JP2006139295A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display by an IPS display mode having a clear outline for a dynamic image with a high-speed liquid crystal response. <P>SOLUTION: Two selective pulses are applied to a scanning line during a single cycle period 110. An electric potential that is the same as the electric potential of a common electrode is provided to a pixel electrode by the first selector pulse 101, a voltage applied to the liquid crystal becomes zero, and a black tone is displayed in a normally-black display mode. An electric potential for displaying an image is supplied to the pixel electrode by the next selector pulse 102 during the same cycle period 110, and the tone changes from the black tone to the tone for displaying an image. When the luminance of each pixel changes to the tone for displaying image, by making the change from the black tone to the tone for displaying image, without fail, the response time to halftone is shortened. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device having a novel configuration.

  Conventional liquid crystal display devices employ a display mode in which an electric field substantially perpendicular to the substrate surface is applied, as represented by a twisted nematic (TN) display mode. However, the TN display mode has a problem that viewing angle characteristics are insufficient. On the other hand, in-plane switching (IPS) display modes have been proposed in Japanese Patent Publication Nos. 63-21907, USP 4345249, WO 91/10936, and Japanese Patent Laid-Open No. 6-160878.

  In this IPS display mode, the liquid crystal driving electrode is formed on one of the pair of substrates sandwiching the liquid crystal, and an electric field having a component parallel to the substrate surface is applied to the liquid crystal. In this IPS display mode, a wider viewing angle can be obtained than in the TN display mode. However, even in the IPS display mode, there is a problem that the color tone changes according to the viewing angle. A multi-domain IPS display mode that solves this problem has been proposed in Japanese Patent Laid-Open No. 9-258269. A liquid crystal display device according to the multi-domain IPS display mode will be described with reference to FIGS. 2, 3, and 4. FIG.

  FIG. 2 is a diagram illustrating a configuration of a liquid crystal display device in a multi-domain IPS display mode. A signal driver 51 that supplies a signal potential to the pixel electrode 35, a scan driver 52 that supplies a potential for selecting a pixel, a common electrode driver 54 that supplies a potential to the common electrode 36, a signal driver 51 and a scan driver 52, and a common A display control device 53 for controlling the electrode driver 54;

  In the substrate 1, a plurality of scanning lines 32 connected to the scanning driver 52, a signal line 31 connected to the signal driver 51 and intersecting the scanning line 32, and in the vicinity of the intersection of the scanning line 32 and the signal line 31. Correspondingly arranged, the first TFT 33 electrically connected to the scanning line 32 and the signal line 31, the pixel electrode 35 corresponding to the signal line 31 and electrically connected to the first TFT 33, and corresponding to the pixel electrode 35 A common electrode 36 and a common electrode connection portion 36 ′ electrically connected to the common electrode 36 and the common electrode driver 54 are provided. A pixel 11 is formed corresponding to a region surrounded by the signal line 31 and the scanning line 32, and the display unit 22 is formed by the plurality of pixels 11.

  FIG. 3 is a diagram showing a circuit arrangement pattern configuration in the vicinity of a pixel of the liquid crystal display device in the multi-domain IPS display mode. The scanning lines 32 and the signal lines 31 intersect with each other, and the pixels 11 are formed corresponding to the area surrounded by the scanning lines 32 and the signal lines 31. The first TFT 33 is disposed in the vicinity of the intersection of the scanning line 32 and the signal line 31, and is electrically connected to the scanning line 32, the signal line 31, and the pixel electrode 35. The common electrode 36 is disposed corresponding to the pixel electrode 35, and the common electrode 36 and the pixel electrode 35 generate an electric field having a component parallel to the substrate surface. The pixel electrode 35, the common electrode 36, and the signal line 31 are bent one or more times within one pixel to form a multi-domain. This is because the rotation direction of the liquid crystal when an electric field is applied is opposite in adjacent domains to widen the viewing angle.

  FIG. 4 is a cross-sectional view taken along the line A-A ′ of FIG. 3. A substrate 1 made of transparent glass, a substrate 2 made of transparent glass, facing the substrate 1, and a liquid crystal layer 34 sandwiched between the substrate 1 and the substrate 2 are provided. The substrate 1 corresponds to the common electrode 36, the signal line 31 disposed above the common electrode 36 via the first insulating film 81, and the electric field corresponding to the common electrode 36 and having a component parallel to the surface of the substrate 1. On the surface of the substrate 1 that does not face the liquid crystal. The pixel electrode 35 that generates liquid crystal, the protective film 82 provided on the pixel electrode 35, the alignment film 85 provided on the protective film 82, and the liquid crystal The polarizing plate 6 is a means for changing the optical characteristics in accordance with the orientation state. The substrate 2 is provided on the light-shielding film 5 that shields light from unnecessary gaps, the light-shielding film 5, and the color filter 4 that expresses colors corresponding to R, G, and B, and the color filter 4. And a flattening film 3 for flattening the unevenness, an alignment film 85 provided on the flattening film 3, and a polarizing plate 6 provided on the surface of the substrate 2 that does not face the liquid crystal.

  The alignment film 85 is rubbed for aligning the liquid crystal. The rubbing direction is parallel to the extending direction DLa of the signal line. The angle formed between one side of the bent pixel electrode and the rubbing direction is 15 degrees, which corresponds to the IPS display mode. The transmission axis of the polarizing plate 6 is oriented parallel or perpendicular to the rubbing direction of the alignment film on the substrate on which each polarizing plate is disposed. The polarizing plate of the substrate 1 and the polarizing plate of the substrate 2 are crossed. It is arranged in Nicole and corresponds to normally black mode. The image display is performed by applying an electric field having a component parallel to the surface of the substrate 1 to the liquid crystal 34 by the common electrode 36 and the pixel electrode 35 and rotating the liquid crystal 34 in a plane substantially parallel to the substrate 1.

Japanese Examined Patent Publication No. 63-21907 USP 4,345,249 specification WO91 / 10936 JP-A-6-160878 JP-A-9-258269

  In recent years, expectations for liquid crystal display devices are not limited to PC (Personal Computer) monitors, but are expanding to liquid crystal televisions that support moving images. As a liquid crystal television, an IPS display mode with a wide viewing angle is suitable for viewing by a plurality of people. In the liquid crystal display device using the IPS display mode, in order to display a moving image more beautifully, it is desired to shorten the response time of the liquid crystal. In the IPS display mode, there is a problem that the color tone changes depending on the drive voltage, and it is desired to solve this problem. Further, in recent years, a problem has been pointed out that the outline of a moving image becomes unclear in a liquid crystal display device.

  Therefore, the first object of the present invention is to shorten the response time of the liquid crystal by a novel pixel structure. A second object of the present invention is to provide a liquid crystal display device that does not cause a change in color tone due to a drive voltage. Furthermore, a third object of the present invention is to provide a liquid crystal display device in which the outline of a moving image is clear.

  The invention according to claim 1 is a light source, a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate, A plurality of scanning lines disposed on the first substrate, a signal line disposed on the first substrate intersecting with the scanning line, and a region surrounded by the scanning line and the signal line. A pixel configured on the first substrate and corresponding to the signal line; a common electrode disposed on the first substrate or the second substrate and corresponding to the pixel electrode; A first active element disposed corresponding to an intersection of the scanning line and the signal line and electrically connected to the signal line, the scanning line, and the pixel electrode; and disposed on the first substrate. And sequentially applying a pulse voltage to the scanning line during one period of displaying one image. In a liquid crystal display device in which a potential for displaying an image is applied to all of the pixel electrodes and held, and then a light source is turned on after a certain period of time, a pulse is applied at the end of the one cycle period. The state immediately before application of the pulse voltage of the liquid crystal of the pixel corresponding to the scanning line to which the voltage is applied is such that the maximum response time from that state to each gradation is shorter than the predetermined period. It is characterized in that a state adjusting means is provided.

  Since a potential for displaying an image is correctly applied to all the pixel electrodes within a certain period before the light source is turned on, the outline of the moving image becomes clear. According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, the state adjusting unit applies the same voltage to all of the pixel electrodes before sequentially applying the pulse voltage to the scanning lines. It is a means to do. By applying the same voltage to all of the pixel electrodes in advance, the liquid crystal around each pixel electrode is brought into a state where the maximum response time to each gradation is shorter than the predetermined period. For example, if the fixed period is 5 ms, the state may be a gradation close to 0, and if the fixed period is 6 ms, the state may be the gradation 0 to 63.

  According to a third aspect of the present invention, in the liquid crystal display device according to the first or second aspect, before the state adjusting unit sequentially applies the pulse voltage to the scanning lines, the potential of the pixel electrode and the common electrode It is characterized by having a means for equalizing the potential of If the fixed period is 5 ms, the potential of the common electrode is applied to a potential corresponding to a gradation close to 0, and if the fixed period is 6 ms, the potential of the common electrode is applied to a potential corresponding to gradations 0 to 63. It ’s fine.

  According to a fourth aspect of the present invention, there is provided a method for driving a liquid crystal display device, comprising: a light source; a first substrate; a second substrate disposed opposite to the first substrate; the first substrate; the second substrate; A plurality of scanning lines disposed on the first substrate, a signal line disposed across the scanning line on the first substrate, the scanning line and the signal A pixel configured corresponding to a region surrounded by a line, a pixel electrode disposed on the first substrate and corresponding to the signal line, and disposed on the first substrate or the second substrate. A first active electrode disposed corresponding to the intersection of the scanning line and the signal line, and electrically connected to the signal line, the scanning line, and the pixel electrode. 1 period period which has an element and the insulating film arrange | positioned on the said 1st board | substrate, and displays 1 image In addition, a pulse voltage is sequentially applied to the scanning lines to apply and hold a potential for displaying an image on all of the pixel electrodes, and then a light source is turned on after a certain period of time. In the driving method, the liquid crystal state of the pixel corresponding to the scanning line to which the pulse voltage is applied at the end of the one cycle period is set, and the maximum response time from each state to each gradation is shorter than the predetermined period. After the state adjustment is performed, a pulse voltage is sequentially applied to the scanning lines. A driving method corresponding to the liquid crystal display device according to claim 1.

  According to a fifth aspect of the present invention, in the driving method of the liquid crystal display device according to the fourth aspect, the state adjustment is performed by applying the same voltage to all the pixel electrodes before sequentially applying the pulse voltage to the scanning lines. It is characterized by being applied. A driving method corresponding to the liquid crystal display device according to claim 2.

  According to a sixth aspect of the present invention, in the method for driving a liquid crystal display device according to the fourth or fifth aspect, the state adjustment is performed by applying the potential of the pixel electrode and the potential before sequentially applying the pulse voltage to the scanning lines. This is performed by making the potential of the common electrode equal. A driving method corresponding to the liquid crystal display device according to claim 3. It should be noted that even if there is a step in the conventional liquid crystal display device, the step of forming the electrode, the contact hole, the light shielding film, etc. only remains, and as described in the present specification, the response time of the liquid crystal It was never intentionally formed to shorten the length.

  According to the present invention, when the electric field is applied, switching starts from a thick region of the liquid crystal layer, so that the response time of the liquid crystal from the zero gradation to the halftone can be shortened, and the change in the color tone accompanying the change in the driving voltage can be reduced. Can be suppressed. In addition, the outline of the moving image can be clearly displayed.

In the liquid crystal display device using the conventional IPS display mode, the thickness of the liquid crystal layer 34 is substantially constant as shown in FIG. It has been found that the response time of the liquid crystal can be shortened by changing the thickness of the liquid crystal layer as shown in FIG. Here, FIG. 6A differs from FIG. 4 only in that the second insulating film 86 is selectively disposed on the protective film 82 and provided with irregularities. The principle of speeding up by this will be described next. The threshold voltage (V _th ) for the change in liquid crystal alignment in the IPS display mode is generally expressed by the following equation [1].

V _th = (π · L / d) · [K ₂ / (ε ₀ · | Δε |)] ^1/2 [1]
[Where, L: gap between electrodes, d: thickness of liquid crystal layer, K ₂ : elastic constant of twist of liquid crystal, ε ₀ : vacuum dielectric constant, Δε: dielectric constant anisotropy of liquid crystal]

That is, the threshold voltage _Vth decreases as the thickness d of the liquid crystal layer increases. This can be interpreted as follows. In the IPS display mode, switching is performed by a balance between electric field energy generated by applying an electric field and elastic energy at which the twisted liquid crystal tries to return to the initial alignment state. When the thickness d of the liquid crystal layer is increased, the distance between the alignment films that fix the rotation of the liquid crystal is increased, so that the elastic energy is reduced. As a result, the twist of the liquid crystal can be induced with less electric field energy, and the threshold voltage _Vth is lowered.

  Therefore, when the thickness of the liquid crystal layer varies, switching occurs as follows. The elastic energy is low in the concave portion where the liquid crystal layer is thick, and the elastic energy is high in the convex portion where the liquid crystal layer is thin. Therefore, FIG. 6B shows a temporal change in the transmittance of light transmitted through the liquid crystal. When an electric field is applied, switching starts from a thick concave portion of the liquid crystal layer, and thereafter, a thin convex portion of the liquid crystal layer. Switching takes place at. When the voltage is low, switching is performed only near the thick concave portion of the liquid crystal layer.

  As described above, in the switching from the black gradation to the halftone, the high-speed switching near the thick concave portion of the liquid crystal layer becomes dominant, so that the response time of the liquid crystal is shortened. FIG. 7 is a diagram showing an aspect of shortening the response time of the liquid crystal by forming the unevenness. The horizontal axis is the gradation after switching, and the vertical axis is the response time. Here, the gradation before switching is zero. As shown in FIG. 7, in the conventional liquid crystal display device having no unevenness, switching from zero gradation to halftone is slow. On the other hand, in the liquid crystal display device provided with unevenness, switching from zero gradation to halftone is accelerated. Furthermore, according to the present invention, it is possible to suppress a change in color tone that accompanies an increase or decrease in drive voltage. It is based on the principle described below. The transmittance (T) in the IPS display mode is generally expressed by the following equation [2].

T = T ₀ · sin ² (2χ) · sin ² (π · d · Δneff / λ) [2]
[Where T _{0 is a} correction coefficient, χ is an angle between the effective optical axis of the liquid crystal and the polarization direction of the incident light, Δn eff is an effective refractive index anisotropy of the liquid crystal, and λ is the wavelength of the incident light).

  Therefore, when the angle χ between the effective alignment direction of the liquid crystal and the polarization direction of the incident light is π / 4 radians (45 degrees), the light having the wavelength λ that is twice the effective retardation diff · Δneff is maximum. The transmittance is shown. That is, when the effective retardation deff · Δneff changes, the wavelength at which the transmittance is maximized changes, so the color tone changes.

  Here, according to the present invention, when an electric field is applied, switching starts from a region where the liquid crystal layer is thick (def), that is, a region where the effective retardation diff · Δneff is large. That is, even when the driving voltage is low, diff · Δneff is already large, the wavelength at which the transmittance is maximum is long, and yellow is emphasized. Therefore, it is possible to correct the problem that the color tone changes from blue to yellow as the drive voltage increases in the conventional liquid crystal display device in which the thickness of the liquid crystal layer shown in FIGS.

  The present invention is based on the principle that when there is a region having a low elastic energy partially, switching starts from that region. Therefore, in order to apply the present invention, it is sufficient that the thickness of the liquid crystal layer varies in the light transmission region, and the shape of the unevenness is not limited at all. The unevenness may be pointed or rounded. Moreover, the area ratio of a recessed part and a convex part is not limited. However, if the shape of the unevenness or the area ratio between the concave and convex portions is changed, the magnitude of the effect of speeding up, the gradation to be speeded up, and the magnitude of the effect of suppressing the color tone change accompanying the increase or decrease in drive voltage Change. However, in order to increase the effect, it is preferable that the thickness of the liquid crystal layer is not less than a certain level. Next, embodiments of the present invention will be described more specifically based on the drawings.

Embodiment 1
The configuration of the first embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG. As shown in FIG. 2, the liquid crystal display device according to the first embodiment has a signal driver 51 that supplies a signal potential to the pixel electrode 35, a scanning driver 52 that supplies a potential for selecting a pixel, and a potential to the common electrode 36. A common electrode driver 54 to be supplied, and a display control device 53 that controls the signal driver 51, the scan driver 52, and the common electrode driver 54 are provided.

  In the substrate 1, a plurality of scanning lines 32 connected to the scanning driver 52, a signal line 31 connected to the signal driver 51 and intersecting the scanning line 32, and in the vicinity of the intersection of the scanning line 32 and the signal line 31. Correspondingly arranged, the first TFT 33 electrically connected to the scanning line 32 and the signal line 31, the pixel electrode 35 corresponding to the signal line 31 and electrically connected to the first TFT 33, and corresponding to the pixel electrode 35 A common electrode 36 and a common electrode connection portion 36 ′ electrically connected to the common electrode 36 and the common electrode driver 54 are provided. One pixel 11 is formed corresponding to one region surrounded by the signal line 31 and the scanning line 32, and the display unit 22 is formed by the plurality of pixels 11.

  FIG. 1 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the first embodiment. The scanning lines 32 and the signal lines 31 intersect with each other, and the pixels 11 are formed corresponding to the area surrounded by the scanning lines 32 and the signal lines 31. The first TFT 33 is disposed in the vicinity of the intersection of the scanning line 32 and the signal line 31, and is electrically connected to the scanning line 32, the signal line 31, and the pixel electrode 35. The common electrode 36 is disposed corresponding to the pixel electrode 35, and the common electrode 36 and the pixel electrode 35 generate an electric field having a component parallel to the substrate surface. The pixel electrode 35, the common electrode 36, and the signal line 31 are bent one or more times within one pixel to form a multi-domain. The second insulating film 86 is disposed in the light transmission region between the pixel electrode 35 and the common electrode 36, and varies the thickness of the liquid crystal layer 34.

  FIG. 5 is a cross-sectional view taken along the line A-A ′ of FIG. 1. A substrate 1 made of transparent glass, a substrate 2 made of transparent glass, facing the substrate 1, and a liquid crystal layer 34 sandwiched between the substrate 1 and the substrate 2 are provided. The substrate 1 corresponds to the common electrode 36, the scanning line 32 (not shown in FIG. 5), the signal line 31 disposed above the common electrode 36 via the first insulating film 81, and the common electrode 36. A pixel electrode 35 that generates an electric field having a component parallel to the surface of the substrate 1, a protective film 82 provided on the pixel electrode 35, and irregularities provided on the protective film 82 that change the thickness of the liquid crystal layer 34. Are formed on the surface of the substrate 1 on the side not facing the liquid crystal, and the optical film is formed according to the alignment state of the liquid crystal. And a polarizing plate 6 as means for changing the characteristics.

  The common electrode 36, the pixel electrode 35, and the signal line 31 are conductors having a film thickness of about 0.2 μm, and CrMo, Al, ITO (Indium Tin Oxide), or the like can be used. The first insulating film 81 and the protective film 82 are insulators having thicknesses of about 0.3 μm and 0.8 μm, respectively, and silicon nitride or the like can be used. The second insulating film 86 is an insulator having a film thickness of about 1 μm, and is formed to provide a step due to unevenness. Both inorganic substances and organic substances can be used. Needless to say, the present invention is not limited to the above film thickness and material.

  The substrate 2 is provided on the light-shielding film 5 that shields light from unnecessary gaps, the light-shielding film 5, and the color filter 4 that expresses colors corresponding to R, G, and B, and the color filter 4. And a flattening film 3 for flattening the unevenness, an alignment film 85 provided on the flattening film 3, and a polarizing plate 6 provided on the surface of the substrate 2 that does not face the liquid crystal. The alignment film 85 is rubbed for aligning the liquid crystal. The rubbing direction is parallel to the extending direction DLa of the signal line. The angle formed between one side of the bent pixel electrode and the rubbing direction is 15 degrees, which corresponds to the IPS display mode.

  The transmission axes of the polarizing plates 6 are oriented parallel or perpendicular to the rubbing direction of the alignment film 85 on the substrate on which each polarizing plate 6 is disposed. Is arranged in crossed Nicols and corresponds to normally black mode. Needless to say, the present invention is not limited to the rubbing angle described above, and can also be applied to a normally white mode.

  Beads are dispersed between the substrate 1 and the substrate 2 to ensure the thickness of the liquid crystal layer 34. Since the beads also exist in the convex portion, the thickness of the liquid crystal layer is determined by the beads on the convex portion. Therefore, in order to make the average value of the thickness of the liquid crystal layer of each pixel uniform over the entire panel, it is desirable that the area of the convex portion is wide. Therefore, a second insulating film 86 for forming irregularities is disposed outside the display area in the pixel as on the signal line 31 and the scanning line 32. Needless to say, a columnar spacer can be used instead of the second insulating film.

  The diameter of the beads is about 3 μm, the thickness of the liquid crystal layer 34 is about 4 μm, the refractive index anisotropy of the liquid crystal layer 34 is about 0.1, and the combination adjusts the retardation. Needless to say, the present invention is not limited to the above-mentioned retardation. There is no restriction on the backlight (not shown), and either a direct type or a side light type can be used. Driving is performed by active matrix driving.

  According to the present invention, since the thickness of the liquid crystal layer varies, the elastic energy is low in the concave portion where the liquid crystal layer is thick, and when the electric field is applied between the pixel electrode 35 and the common electrode 36, the region of the concave portion Switching starts from. Therefore, switching from zero gradation to halftone can be speeded up, and a liquid crystal display device with excellent moving image display quality can be provided. Needless to say, the present invention can be applied even if the protective film 82 is provided with unevenness without using the second insulating film 86 for forming unevenness. Furthermore, the thickness of the liquid crystal layer 34 is varied in the light transmission region by forming a concave and convex second insulating film on the entire surface of the display unit 22 instead of forming the concave and convex depending on the presence or absence of the second insulating film 86. Needless to say, the present invention can also be applied to cases.

[Comparative Example 1]
The first comparative example of the present invention differs from the first embodiment only in that the second insulating film 86 is not formed and the thickness of the liquid crystal layer 34 is substantially constant in the light transmission region. FIG. 3 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of the pixel of the first comparative example. Unlike the first embodiment, the second insulating film is not formed. 4 is a cross-sectional view taken along the line AA ′ of FIG. Unlike the first embodiment, there is no second insulating film, and the thickness of the liquid crystal layer is substantially constant. For this reason, the response time of the liquid crystal from the zero gradation to the halftone is slower than that of the first embodiment.

[Embodiment 2]
The second embodiment is different from the first embodiment only in the shape of the second insulating film 86. Therefore, this will be described with reference to FIGS. FIG. 8 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the second embodiment. Unlike Embodiment 1, the shape and arrangement of the second insulating film are randomly formed.

  FIG. 9 is a cross-sectional view taken along the line A-A ′ of FIG. 8. Unlike Embodiment 1, the shape and arrangement of the second insulating film and the height of the unevenness are randomly formed. However, it is desirable that the area ratio between the concave and convex portions within one pixel and the average height of the concave and convex portions be the same among the pixels. If they do not match, the magnitude of the speed-up effect changes for each pixel, which causes problems such as uneven brightness.

  According to the present invention, since the thickness of the liquid crystal layer varies as in the first embodiment, the elastic energy is low in the concave portion where the liquid crystal layer is thick, and an electric field is applied between the pixel electrode 35 and the common electrode 36. Switching starts from the region of the recess. Therefore, switching from zero gradation to halftone can be speeded up, and a liquid crystal display device with excellent moving image display quality can be provided.

[Embodiment 3]
Embodiment 3 differs from Embodiment 1 in the shape and arrangement of the second insulating film. This will be described with reference to FIGS. FIG. 10 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the third embodiment. FIG. 11 is a cross-sectional view taken along the line AA ′ of FIG.

  This embodiment is different from the first embodiment in that there is only one step between the pixel electrode 35 and the common electrode 36 due to the unevenness formed by the second insulating film 86. Further, the pixel electrode 35 is disposed so as to overlap the convex portion, and the common electrode 36 is superimposed on the concave portion. Thereby, the pattern width of the unevenness becomes larger than that of the first embodiment, and the processing of the second insulating film 86 is facilitated.

[Embodiment 4]
The fourth embodiment differs from the third embodiment in the arrangement of the electrode and the second insulating film. This will be described with reference to FIGS. FIG. 12 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the fourth embodiment. FIG. 13 is a cross-sectional view taken along the line AA ′ of FIG.

  In the fourth embodiment, unlike the third embodiment, the pixel electrode 35 and the signal line 31 are arranged in a layer above the second insulating film 86. The common electrode 36 is disposed on the substrate 1 together with the scanning line 32 (not shown in FIG. 13). Here, in the third embodiment, as can be seen from FIG. 11, among the electric force lines 21 of the electric field generated between the pixel electrode 35 and the common electrode 36, most of the electric force lines 21 passing through the liquid crystal layer are the first. 2 insulating film 86 also passes. In other words, an electric field is applied to the liquid crystal layer 34 through the second insulating film 86. On the other hand, in the fourth embodiment, as can be seen from FIG. 13, since the pixel electrode 35 is disposed above the second insulating film 86, an electric field is applied to the liquid crystal layer 34 without passing through the second insulating film 86. . Therefore, in the fourth embodiment, the drive voltage can be reduced as compared with the third embodiment.

  Even when the protective film 82 is not formed, when the protective film 82 and the second insulating film 86 are collectively processed, or when the protective film 82 and the second insulating film 86 are integrated with the same material. Needless to say, the present invention is applicable because the thickness of the liquid crystal layer 34 can be varied.

[Embodiment 5]
The fifth embodiment is different from the fourth embodiment in the arrangement of the second insulating film. This will be described with reference to FIGS. 14, 15, and 16. FIG. FIG. 14 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the fifth embodiment. FIG. 15 is a diagram showing a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 2 according to the fifth embodiment. FIG. 16 is a cross-sectional view taken along the line AA ′ of FIG.

  The substrate 1 includes a common electrode 36, a scanning line 32 (not shown in FIG. 16), a signal line 31 disposed above the common electrode 36 via a first insulating film 81, and a pixel electrode 35. The pixel electrode 35 that generates an electric field having a component parallel to one surface, the protective film 82 provided on the pixel electrode 35, the alignment film 85 provided on the protective film 82, and the liquid crystal of the substrate 1 The polarizing plate 6 is provided on the non-facing surface and is a means for changing optical characteristics in accordance with the alignment state of the liquid crystal.

  The substrate 2 is provided on the light-shielding film 5 that shields light from unnecessary gaps, the light-shielding film 5, and the color filter 4 that expresses colors corresponding to R, G, and B, and the color filter 4. On the flattening film 3 for flattening the unevenness, the second insulating film 86 provided on the flattening film 3 and forming the unevenness for changing the thickness of the liquid crystal layer 34, and the second insulating film 86 The alignment film 85 is provided, and the polarizing plate 6 is provided on the surface of the substrate 2 that does not face the liquid crystal.

  In the fifth embodiment, unlike the fourth embodiment, a second insulating film 86 for forming irregularities that change the thickness of the liquid crystal layer is disposed on the substrate 2. Therefore, since the second insulating film 86 is separated from the wiring or electrode such as the pixel electrode 35, the common electrode 36, the signal line 31, and the scanning line 32, and the second insulating film 86, The stray capacitance such as between the pixel electrode 35 and the common electrode 36 does not fluctuate, and display unevenness is less likely to be induced.

[Embodiment 6]
The sixth embodiment differs from the fifth embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 14, 17, 18 and 19. FIG. A diagram showing a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 of the sixth embodiment is the same as FIG. FIG. 17 is a diagram showing a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 2 according to the sixth embodiment. 18 is a cross-sectional view taken along the line AA ′ of FIG. FIG. 19 is a cross-sectional view taken along the line BB ′ of FIGS. 14 and 17.

  In Embodiment 6, the extending direction DLb of the unevenness formed by the second insulating film 86 is shifted from the extending direction DLc of the pixel electrode and intersects substantially vertically. Therefore, even when misalignment occurs between the substrate 1 and the substrate 2, the positional relationship of the second insulating film 86 with respect to the light shielding film 5 does not change for each pixel, and between the pixel electrode 35 and the common electrode 36. In each of the regions, the area ratio between the concave and convex portions does not change, and the effect of shortening the response time of the liquid crystal does not change.

[Embodiment 7]
The seventh embodiment is different from the sixth embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 14, 20 and 21. FIG. The circuit arrangement pattern configuration in the vicinity of the pixel on the substrate 1 of the seventh embodiment is the same as that shown in FIG. FIG. 20 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 2 according to the seventh embodiment. 21 is a cross-sectional view taken along the line AA ′ of FIG. In the seventh embodiment, the step extending direction DLd due to the unevenness formed by the second insulating film 86 coincides with the initial alignment direction DLe of the liquid crystal. Therefore, when the alignment film 85 is subjected to the rubbing process, the rubbing process can be performed uniformly without overcoming the steps due to the unevenness in the light transmission region, and alignment defects and the like are hardly induced.

[Embodiment 8]
The eighth embodiment differs from the seventh embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 22 and 23. FIG. FIG. 22 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the eighth embodiment. 23 is a cross-sectional view taken along the line AA ′ of FIG. 22. The substrate 1 includes a common electrode 36, a scanning line 32 (not shown in FIG. 23), and a first insulation disposed on the common electrode 36. A film 81, a protective film 82 disposed on the first insulating film 81, a second insulating film 86 disposed on the protective film 82 and forming irregularities that vary the thickness of the liquid crystal layer 34, and a second A signal line 31 disposed on the insulating film 86, a pixel electrode 35 disposed above the second insulating film 86 and generating an electric field having a component parallel to the surface of the substrate 1 corresponding to the common electrode 36; And an alignment film 85 disposed on the pixel electrode 35 and a polarizing plate 6 that is provided on the surface of the substrate 1 that does not face the liquid crystal and that changes the optical characteristics in accordance with the alignment state of the liquid crystal. The common electrode 36 is disposed on the substrate 1 together with the scanning line 32.

  The substrate 2 is provided on the light-shielding film 5 that shields light from unnecessary gaps, the light-shielding film 5, and the color filter 4 that expresses colors corresponding to R, G, and B, and the color filter 4. And a flattening film 3 for flattening the unevenness, an alignment film 85 provided on the flattening film 3, and a polarizing plate 6 provided on the surface of the substrate 2 that does not face the liquid crystal. In the eighth embodiment, unlike the seventh embodiment, a second insulating film 86 for forming irregularities that change the thickness of the liquid crystal layer is disposed on the substrate 1. For this reason, even when misalignment occurs between the substrate 1 and the substrate 2, the second insulating film 86 is not affected, so that the effect of shortening the response time of the liquid crystal does not vary over all pixels.

  Further, unlike the fourth embodiment, the eighth embodiment differs from the fourth embodiment in that the step extending direction DLd due to the unevenness formed by the second insulating film 86 coincides with the initial alignment direction DLe of the liquid crystal. Therefore, when the alignment film 85 is subjected to a rubbing process, the rubbing process can be performed uniformly without overcoming the steps associated with the unevenness in the light transmission region, and alignment defects and the like are not induced.

[Embodiment 9]
The ninth embodiment is different from the eighth embodiment only in the arrangement and shape of the second insulating film 86, the pixel electrode 35, and the common electrode 36. Therefore, this will be described with reference to FIG. FIG. 24 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the ninth embodiment. In the ninth embodiment, unlike the eighth embodiment, the pixel electrode 35 and the common electrode 36 are not bent. Therefore, the rubbing direction is inclined 15 degrees with respect to the extending direction of the signal line 31. However, the angle between one side of the pixel electrode 35 and the rubbing direction is 15 degrees, as in the eighth embodiment.

  The extending direction of the step due to the unevenness formed by the second insulating film 86 is inclined by 15 degrees with respect to the extending direction of the signal line 31. However, as in the eighth embodiment, the extending direction DLd of the step due to the unevenness formed by the second insulating film 86 matches the initial alignment direction DLe of the liquid crystal. Therefore, as in the eighth embodiment, in the ninth embodiment, when the alignment film 85 is subjected to the rubbing process, the rubbing process can be performed uniformly without overcoming the unevenness in the light transmission region. It does not induce defects.

[Embodiment 10]
The tenth embodiment differs from the eighth embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 25 and 26. FIG. FIG. 25 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the tenth embodiment. 26 is a cross-sectional view taken along the line AA ′ of FIG. 25. Unlike the eighth embodiment, the pixel electrode 35 and the common electrode 36 are over the step due to the unevenness due to the second insulating film 86. Absent. For example, in the portion C shown in FIG. 22R> 2 in the eighth embodiment, the pixel electrode 35 is over the end of the second insulating film 86. On the other hand, in the portion C shown in FIG. 25 of the tenth embodiment, the pixel electrode 35 does not get over the second insulating film 86. That is, in FIG. 22, when a cross section parallel to the AA ′ cross section is taken, the pixel electrode 35 is located on the second insulating film 86 (upper step) and on the protective film 82 (lower step). 25, the second insulating film 86 is disposed avoiding the pixel electrode 35 in FIG. 25, and the pixel electrode 35 is on the protective film 82 even if the cross section is parallel to the AA ′ cross section. (Below the step). Therefore, in the tenth embodiment, there is no defect such as the pixel electrode 35 being cut due to a step due to the unevenness due to the second insulating film 86.

[Embodiment 11]
The eleventh embodiment differs from the tenth embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 27 and 28. FIG. FIG. 27 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the eleventh embodiment. FIG. 28 is a cross-sectional view taken along the line AA ′ of FIG. 27. Unlike the tenth embodiment, the step due to the unevenness due to the second insulating film 86 overlaps the pixel electrode 35 and the common electrode 36. is doing. For example, in the portion C shown in FIG. 25 of the tenth embodiment, the step due to the unevenness due to the second insulating film 86 is not superimposed on the pixel electrode 35. On the other hand, in the portion C shown in FIG. 27 of the eleventh embodiment, a step due to the unevenness due to the second insulating film 86 is superimposed on the pixel electrode 35. Therefore, in the eleventh embodiment, even if the rubbing process is insufficient at the step portion due to the unevenness due to the second insulating film 86 and alignment failure occurs, if the pixel electrode 35 and the common electrode 36 are opaque conductors, Since the defect is hidden by the pixel electrode 35 and the common electrode 36, the display is not affected.

  In the eleventh embodiment, as in the tenth embodiment, the level difference caused by the unevenness due to the second insulating film 86 overlaps the pixel electrode 35 and the common electrode 36, but does not get over. That is, in FIG. 27, the second insulating film 86 is disposed so as to avoid the pixel electrode 35, but the pixel electrode 35 runs over the second insulating film 86 at the end. For this reason, even if the cross section parallel to the A-A ′ cross section is taken, the pixel electrode 35 is approximately on the protective film 82 (lower step), and only the end portion is on the second insulating film 86 (upper step). Therefore, as in the case of the tenth embodiment, defects such as the pixel electrode 35 being cut due to a step due to the unevenness due to the second insulating film 86 do not occur.

[Embodiment 12]
The twelfth embodiment is different from the ninth embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIG. FIG. 29 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel on the substrate 1 according to the twelfth embodiment. In the twelfth embodiment, unlike the ninth embodiment, the pixel electrode 35 and the common electrode 36 do not get over the step due to the unevenness due to the second insulating film 86. For example, in the portion C shown in FIG. 24 of the ninth embodiment, the pixel electrode 35 gets over the end of the second insulating film 86. On the other hand, in the portion C shown in FIG. 29 of the twelfth embodiment, although the pixel electrode 35 partially overlaps the second insulating film 86, it does not get over. In other words, in FIG. 29, the second insulating film 86 is disposed so as to avoid the pixel electrode 35, but the pixel electrode 35 runs over the second insulating film 86 at the end. For this reason, even if a cross section such as parallel to the horizontal axis is taken, the pixel electrode 35 is approximately on the protective film 82 (lower part of the step), and only the end part is on the second insulating film 86 (upper part of the step).

  Therefore, in the twelfth embodiment, as in the tenth embodiment, there is no defect such as the pixel electrode 35 being cut due to a step due to the unevenness due to the second insulating film 86. Further, the step due to the unevenness due to the second insulating film 86 overlaps with the pixel electrode 35 and the common electrode 36. Therefore, in the twelfth embodiment, even when the rubbing process is insufficient at the step portion due to the unevenness due to the second insulating film 86 and alignment failure occurs, if the pixel electrode 35 and the common electrode 36 are opaque conductors, Since the defect is hidden by the pixel electrode 35 and the common electrode 36, the display is not affected.

[Embodiment 13]
The thirteenth embodiment differs from the eleventh embodiment in the arrangement and shape of the second insulating film. This will be described with reference to FIGS. 30 and 31. FIG. FIG. 30 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the thirteenth embodiment. FIG. 31 is a cross-sectional view taken along the line AA ′ of FIG.

  The thirteenth embodiment differs from the eleventh embodiment in that there is only one step between the pixel electrode 35 and the common electrode 36 due to the unevenness formed by the second insulating film 86. Further, the pixel electrode 35 is disposed so as to overlap the convex portion, and the common electrode is superimposed on the concave portion. Thereby, the pattern width of the unevenness becomes larger than that of the eleventh embodiment, and the processing of the second insulating film 86 is facilitated.

  Since the pixel electrode 35 is disposed above the second insulating film 86, an electric field can be applied to the liquid crystal layer 34 without passing through the second insulating film 86, and an increase in driving voltage is suppressed. . Furthermore, since the extending direction DLd of the level difference caused by the unevenness formed by the second insulating film 86 coincides with the initial alignment direction DLe of the liquid crystal, when the alignment film 85 is rubbed, in the light transmission region Rubbing treatment can be performed uniformly without overcoming the steps due to the unevenness, and alignment defects are hardly induced.

  Further, in the light transmission region, the pixel electrode 35 and the common electrode 36 do not get over the step due to the unevenness due to the second insulating film 86, so that a defect such as the pixel electrode 35 being cut by the step does not occur. That is, in FIG. 30, the pixel electrode 35 and the signal line 31 are all formed on the second insulating film 86 and do not reach the step.

[Embodiment 14]
The fourteenth embodiment is different from the thirteenth embodiment in the shape and arrangement of the signal line 31, the pixel electrode 35, the common electrode 36, and the second insulating film 86. This will be described with reference to FIGS. 32 and 33. FIG. FIG. 32 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the fourteenth embodiment. The scanning lines 32 and the signal lines 31 intersect with each other, and pixels are formed corresponding to a region surrounded by the scanning lines 32 and the signal lines 31. The first TFT 33 is disposed in the vicinity of the intersection of the scanning line 32 and the signal line 31, and is electrically connected to the scanning line 32, the signal line 31, and the pixel electrode 35. The common electrode 36 is disposed corresponding to the pixel electrode 35, and the common electrode 36 and the pixel electrode 35 generate an electric field having a component parallel to the substrate surface. The pixel electrode 35, the common electrode 36, and the signal line 31 are bent one or more times within one pixel to form a multi-domain. The second insulating film 86 is disposed in the light transmission region between the pixel electrode and the common electrode, and varies the thickness of the liquid crystal layer 34. The signal line 31 and the common electrode 36 overlap with each other via the second insulating film 86.

  33 is a cross-sectional view taken along the line A-A ′ of FIG. 32. A substrate 1 made of transparent glass, a substrate 2 made of transparent glass, facing the substrate 1, and a liquid crystal layer 34 sandwiched between the substrate 1 and the substrate 2 are provided. The substrate 1 includes a first insulating film 81, a signal line 31 and a pixel electrode 35 disposed on the first insulating film 81, a protective film 82 disposed on the signal line 31 and the pixel electrode 35, and a protective film 82. A second insulating film 86 disposed above, a common electrode 36 disposed so as to overlap the signal line 31 via the second insulating film 86, an alignment film 85 disposed at the interface with the liquid crystal 34, and a substrate The polarizing plate 6 is provided on the surface of the first liquid crystal that does not face the liquid crystal and is a means for changing the optical characteristics in accordance with the alignment state of the liquid crystal. The common electrode 36 is disposed on the first insulating film 81 together with the scanning line 32 (not shown in FIG. 33).

  The common electrode 36, the pixel electrode 35, and the signal line 31 are conductors having a film thickness of about 0.2 μm, and CrMo, Al, ITO (Indium Tin Oxide), or the like can be used. The first insulating film 81 and the protective film 82 are insulators having thicknesses of about 0.3 μm and 0.8 μm, respectively, and silicon nitride or the like can be used. The second insulating film 86 is an insulator having a thickness of about 1 μm, and an inorganic material or an organic material can be used. Needless to say, the present invention is not limited to the above film thickness. The substrate 2 is provided on the light-shielding film 5 that shields light from unnecessary gaps, the light-shielding film 5, and the color filter 4 that expresses colors corresponding to R, G, and B, and the color filter 4. And a flattening film 3 for flattening the unevenness, an alignment film 85 provided on the flattening film 3, and a polarizing plate 6 provided on the surface of the substrate 2 that does not face the liquid crystal.

  The alignment film 85 is rubbed for aligning the liquid crystal. The rubbing direction is parallel to the extending direction of the signal line. The angle formed between one side of the bent pixel electrode and the rubbing direction is 15 degrees, which corresponds to the IPS display mode. The transmission axis of the polarizing plate 6 is oriented parallel or perpendicular to the rubbing direction of the alignment film on the substrate on which each polarizing plate is disposed. The polarizing plate of the substrate 1 and the polarizing plate of the substrate 2 are crossed. It is arranged in Nicole and corresponds to normally black mode. Needless to say, the present invention is not limited to the rubbing angle described above, and can also be applied to a normally white mode.

  Beads are dispersed between the substrate 1 and the substrate 2 to ensure the thickness of the liquid crystal layer. Since the beads also exist in the convex portion, the thickness of the liquid crystal layer is determined by the beads on the convex portion. Therefore, in order to make the average value of the thickness of the liquid crystal layer of each pixel uniform over the entire panel, it is desirable that the area of the convex portion is wide. Therefore, the second insulating film 86 for forming irregularities is also disposed outside the display area in the pixel on the signal line 31 and the scanning line 32. Needless to say, columnar spacers can be applied to the present invention.

  The diameter of the beads is about 3 μm, the refractive index anisotropy of the liquid crystal layer is about 0.1, and the retardation is adjusted by this combination. Needless to say, the present invention is not limited to the above-mentioned retardation. There is no restriction on the backlight (not shown), and either a direct type or a side light type can be used. Driving is performed by active matrix driving.

  According to the fourteenth embodiment, since the thickness of the liquid crystal layer varies, the elastic energy is low in the concave portion where the liquid crystal layer is thick, and when the electric field is applied between the pixel electrode 35 and the common electrode 36, Switching starts from the region. Therefore, switching from zero gradation to halftone can be speeded up, and a liquid crystal display device with excellent moving image display quality can be provided.

  Further, when an electric field is applied, switching starts from a region where the liquid crystal layer has a large thickness (defeff), that is, a region where the effective retardation deff · Δneff is large, so that the transmittance is already maximum even when the driving voltage is low. The wavelength becomes long and yellow is emphasized. This can correct the problem that the color tone changes from blue to yellow as the drive voltage increases in a conventional liquid crystal display device in which the thickness of the liquid crystal layer does not change.

  In the fourteenth embodiment, unlike the thirteenth embodiment, the signal line 31 and the common electrode 36 overlap with each other via the second insulating film 86. In the thirteenth embodiment, the two common electrodes 36 arranged on both sides of the signal line 31. Are grouped together. Therefore, the aperture ratio is improved without increasing the mask for the photoresist process.

  In the fourteenth embodiment, unlike the thirteenth embodiment, the signal line 31 and the common electrode 36 are overlapped with each other via the second insulating film 86, so that the area ratio of the concave portion and the convex portion in the light transmission region is the same. In comparison with the thirteenth embodiment, the fourteenth embodiment can take a larger area of the second insulating film superimposed on the signal line 31 than the thirteenth embodiment. Accordingly, since the thickness of the liquid crystal layer 34 is determined by the beads on the convex portion, the average value of the thickness of the liquid crystal layer 34 of each pixel is uniform over the entire panel as compared with the thirteenth embodiment. Easy to do.

  Furthermore, unlike Embodiment 11, there is only one step between the pixel electrode 35 and the common electrode 36 due to the unevenness formed by the second insulating film 86. In addition, the pixel electrode 35 is disposed so as to overlap the concave portion, and the common electrode 36 is superimposed on the convex portion. Thereby, the shape of the unevenness becomes larger than that of the eleventh embodiment, and the processing of the second insulating film 86 is facilitated. In addition, since the common electrode 36 superimposed on the convex portion is disposed above the second insulating film 86, an electric field can be applied to the liquid crystal layer 34 without passing through the second insulating film 86, and the drive voltage The rise of is suppressed.

  Furthermore, since the extending direction DLd of the level difference caused by the unevenness formed by the second insulating film 86 coincides with the initial alignment direction DLe of the liquid crystal, when the alignment film 85 is rubbed, in the light transmission region Rubbing treatment can be performed uniformly without overcoming the steps due to the unevenness, and alignment defects are hardly induced. Further, in the light transmission region, the pixel electrode 35 and the common electrode 36 do not get over the step due to the unevenness due to the second insulating film 86, so that a defect such as the pixel electrode 35 being cut by the step does not occur.

[Embodiment 15]
The fifteenth embodiment differs from the fourteenth embodiment in the shape and arrangement of the second insulating film 86. This will be described with reference to FIGS. 34 and 35. FIG. FIG. 34 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the fifteenth embodiment. FIG. 35 is a cross-sectional view taken along the line AA ′ of FIG.

  In the fifteenth embodiment, unlike the fourteenth embodiment, the second insulating film 86 is selectively formed at a portion where the signal line 31 and the common electrode 36 overlap with each other and with a width smaller than the common electrode 36. Therefore, as shown in FIG. 35, the common electrode 36 is formed so as to cover the second insulating film 86. As a result, the noise electric field passing through the second insulating film 86 and the recess of the liquid crystal layer 34 out of the noise electric field generated between the signal line 31 and the pixel electrode 35 as indicated by the electric lines of force 21. The display quality can be improved.

[Embodiment 16]
In the sixteenth embodiment, the shape and arrangement of the common electrode 36 are different from those in the fourteenth embodiment. This will be described with reference to FIGS. 36 and 37. FIG. FIG. 36 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the sixteenth embodiment. FIG. 37 is a cross-sectional view taken along the line AA ′ of FIG.

  In the sixteenth embodiment, unlike the fourteenth embodiment, the common electrode 36 and the alignment film 85 are disposed on the second insulating film 86 in a portion where the signal line 31 and the second insulating film 86 overlap each other. That is, in FIG. 33 of the fourteenth embodiment, the common electrode 36 is superimposed on the entire surface of the signal line 31 (however, it means the entire surface in the section AA ′ in FIG. 36). A common electrode 36 is superimposed on a part of the signal line 31. Therefore, the capacitance generated between the signal line 31 and the common electrode 36 can be changed by changing the overlapping area. Here, in order to cause a delay of the video signal passing through the signal line 31, it is important to adjust this capacity.

  In other words, in the fourteenth embodiment, the capacitance can be changed by changing the thickness of the second insulating film 86, but in the sixteenth embodiment, not only the thickness of the second insulating film 86 but also the signal line 31 is common. The capacitance can also be changed by changing the area where the electrode 36 overlaps. Therefore, the degree of freedom regarding the thickness of the second insulating film 86 is widened, and the thickness of the second insulating film can be determined so that the effect of speeding up due to the unevenness of the thickness of the liquid crystal layer 34 is optimized. In other words, Embodiment 16 can independently optimize the variation in the thickness of the liquid crystal layer 34 and optimize the capacitance between the signal line 31 and the common electrode 36.

[Embodiment 17]
The seventeenth embodiment is different from the fourteenth embodiment only in the shape of the protective film 82. This will be described with reference to FIGS. 32 and 38. FIG. FIG. 32 is a diagram illustrating a circuit arrangement pattern configuration in the vicinity of a pixel according to the seventeenth embodiment. FIG. 38 is a cross-sectional view taken along the line AA ′ of FIG.

  The seventeenth embodiment is different from the fourteenth embodiment in that a protective film 82 that is an insulating film having irregularities is arranged on the substrate 1 and is different from the second insulating film 86 that forms irregularities. The film 86 and the recess of the protective film 82 are overlapped. That is, as shown in FIG. 38, in the seventeenth embodiment, the protective film 82 has irregularities, and the insulating film 86 is disposed in the concave portion of the protective film 82, so that the thickness of the liquid crystal layer is larger than that in the fourteenth embodiment. The fluctuation is small.

  That is, in the seventeenth embodiment, the variation in the thickness of the liquid crystal layer 34 can be changed in both the second insulating film 86 and the protective film 82. Therefore, the capacitance between the signal line 31 and the common electrode 36 can be changed by the thickness of the second insulating film, and the variation in the thickness of the liquid crystal layer 34 is caused by the thickness of the second insulating film 86 and the unevenness of the protective film 82. It can be changed in combination with the size.

  In other words, the seventeenth embodiment can independently optimize the variation in the thickness of the liquid crystal layer 34 and optimize the capacitance between the signal line 31 and the common electrode 36. Note that the same effect can be obtained by forming the protective film 82 from the beginning so that the cross-sectional shape of the second insulating film 86 and the protective film 82 in this embodiment is combined.

[Embodiment 18]
The eighteenth embodiment is different from the first embodiment only in the driving method. This will be described with reference to FIG. FIG. 39 is an example of the time change of the potential of each wiring and electrode and the time change of the voltage applied to the liquid crystal in the eighteenth embodiment.

  In the eighteenth embodiment, two selection pulses are supplied to the scanning line during one cycle period 110. By the first selection pulse 101, the same potential as that of the common electrode is supplied to the pixel electrode, the voltage applied to the liquid crystal becomes zero, and the present liquid crystal display device in the normally black display mode displays a black gradation. In the same period 110, the next selection pulse 102 supplies a potential for displaying an image to the pixel electrode, and the liquid crystal display device changes from a black gradation to a gradation for displaying an image. As described above, the eighteenth embodiment uses a driving method having means for equalizing the potential of the pixel electrode and the potential of the common electrode during one period of displaying one image.

  Therefore, whenever the luminance of each pixel changes to a gradation for displaying an image, it always changes from a black gradation to a gradation for displaying an image. In the eighteenth embodiment, since the response time from the black gradation to the halftone can be shortened, the switching from the black gradation to the halftone that has been speeded up is frequently used by combining the above driving method and the circuit configuration. As a result, the display quality of the moving image is improved.

  In the eighteenth embodiment, the active matrix driving in the first embodiment is replaced with the above driving method. Therefore, in Embodiments 2 to 17 using active matrix driving, it goes without saying that the same effect as in Embodiment 18 can be obtained by replacing active matrix driving with the above driving method.

[Embodiment 19]
The nineteenth embodiment is different from the eighteenth embodiment only in the driving method. This will be described with reference to FIGS. 40 and 41. FIG. A backlight light source may be used.
FIG. 40 is a diagram showing the configuration of the liquid crystal display device according to the nineteenth embodiment. The liquid crystal display device according to the nineteenth embodiment includes a signal driver 51 that supplies a signal potential to the pixel electrode 35, a scanning driver 52 that supplies a potential for selecting a pixel, a common electrode driver 54 that supplies a potential to the common electrode 36, A display controller 53 that controls the signal driver 51, the scan driver 52, and the common electrode driver 54 is provided.

  In the substrate 1, a plurality of scanning lines 32 connected to the scanning driver 52, a signal line 31 connected to the signal driver 51 and intersecting the scanning line 32, and in the vicinity of the intersection of the scanning line 32 and the signal line 31. Correspondingly arranged, the first TFT 33 electrically connected to the scanning line 32 and the signal line 31, the pixel electrode 35 corresponding to the signal line 31 and electrically connected to the first TFT 33, and corresponding to the pixel electrode 35 A common electrode 36, a scanning line different from the scanning line 32 to which the first TFT is connected, a second TFT 33 ′ electrically connected to the pixel electrode 35 and the common electrode 36, a common electrode 36 and a common electrode driver 54 An electrically connected common electrode wiring 36 "is provided.

  FIG. 41 shows an example of the time change of the potential of each wiring and electrode and the time change of the voltage applied to the liquid crystal in the nineteenth embodiment. In the driving of the nineteenth embodiment, as shown in FIG. 41, when 103 negative selection pulses are supplied to the common electrode 36 through the common electrode wiring 36 ″, the scanning line to which the second TFT 33 ′ of FIG. 40 is connected. Therefore, the second TFT 33 'is turned on, the potential of the pixel electrode 35 and the potential of the common electrode 36 are equal, and this liquid crystal display device in the normally black display mode is In this case, since the scanning lines 32 are sequentially selected from the first to the m-th, only the second TFT 33 'connected to the selected scanning line is turned on when the common electrode wiring 36 "is driven. The potential of the pixel electrode 35 and the potential of the common electrode 36 are equal. Subsequently, a potential for displaying an image is supplied to the pixel electrode by the selection pulse 102 in the same period 110, and the present liquid crystal display device changes from a black gradation to a gradation for displaying an image. In this case, since the next scanning line 32 is selected, only the first TFT 33 connected to the pixel electrode 35 having the same potential as the common electrode is turned on, and the potential for displaying an image is the pixel electrode. To be supplied. In this way, as the scanning lines are sequentially selected from the first to the mth, the pixel electrodes connected to the scanning lines are also sequentially selected, and once the potential of the common electrode becomes equal, an image is displayed. Therefore, the potential to be supplied is supplied.

  As described above, the nineteenth embodiment uses a driving method having means for equalizing the potential of the pixel electrode and the potential of the common electrode during one period of displaying one image. Therefore, whenever the luminance of each pixel changes to a gradation for displaying an image, it always changes from a black gradation to a gradation for displaying an image. Since the nineteenth embodiment has a configuration capable of shortening the response time from the black gradation to the halftone, the switching from the black gradation to the halftone, which is accelerated, is frequently used by combining the driving method and the circuit configuration. As a result, the display quality of the moving image is improved.

  In addition, the nineteenth embodiment is different from the eighteenth embodiment in that the means for equalizing the potential of the pixel electrode and the common electrode is independent of the signal line 31, so that the supply of the potential for displaying an image and the pixel The potential of the electrode and the potential of the common electrode can be made equal at different times in different pixels, and the ratio of the time for displaying the black gradation and the time for displaying the image can be arbitrarily changed. it can.

  In the nineteenth embodiment, the active matrix driving in the first embodiment is replaced with the above driving method. Therefore, in Embodiments 2 to 17 using active matrix driving, it goes without saying that the same effect as in Embodiment 19 can be obtained by replacing active matrix driving with the above driving method.

[Embodiment 20]
The embodiment 20 differs from the embodiment 1 only in that, instead of the rubbing treatment, a photoreactive material layer is disposed in a portion in contact with the liquid crystal layer and photo-alignment is applied. That is, a material suitable for photo-alignment was used as the alignment film 85, and the light was polarized in a substantially straight line to determine the initial alignment direction of the liquid crystal layer 34. For this reason, it becomes difficult to induce alignment failure or the like in the stepped portion due to the unevenness. Polyvinyl cinnamate or the like can be used as the photoreactive material. In addition, Embodiment 20 only changes the alignment process in Embodiment 1. Therefore, it goes without saying that in Embodiments 2 to 19, the same effects as those in Embodiment 20 can be obtained by applying photo-alignment to the alignment treatment.

[Comparative Example 2]
Comparative Example 2 of the present invention differs from Embodiments 1 to 20 only in the driving method. Therefore, this will be described with reference to FIG. FIG. 42 is an example of the time change of the potential of each wiring and electrode of Comparative Example 2 and the time change of the luminance of the pixel.

  In Comparative Example 2, the selection pulse is sequentially supplied to all the scanning lines, and the potential for displaying on all the pixel electrodes is applied from the signal line to the pixel electrodes and held, and then the backlight is turned on for display. Is done. In the conventional display method in which the potential is applied to the pixel electrode while the backlight is kept on, there is a problem that the outline of the moving image becomes unclear, but using the drive method of this comparative example 2, By performing intermittent display, it is possible to prevent blurring of the outline. However, in order to realize a uniform display on the entire screen, it is necessary to turn on the backlight after the liquid crystal has completely responded after applying a voltage to the pixel electrode. There is a problem that cannot be obtained.

  In the example shown in FIG. 42, voltage waveforms (selection pulses) VG (1) to VG (m) are sequentially applied to the 1st to mth scanning lines, and the signal voltage VD corresponding to each display is sequentially applied to the pixel electrodes. Write. After the voltage is written to the pixel electrode corresponding to the last scanning line (m-th), the backlight is turned on after a certain period (5 ms in this case). This time is called one frame. In this case, 16.6 ms. In FIG. 42, the luminances B (1) to B (m) of the pixels indicate the luminances of the pixels connected to the 1-mth scanning lines corresponding to the specific signal lines. The period during which the backlight is on is indicated by hatching. In this example, the display has not changed in the (1) and (2) th frames. (3) After the display changes from the image A to the image B in the third frame, the display does not change again in the frames (4) and (5).

  From the (2) th frame to the (3) th frame, the display of the pixels corresponding to the first and second scanning lines is changed from the highest gradation level (255 level) to the intermediate gradation level. The luminance B (1) and B (2) of these pixels has a desired time (for displaying the image B) since there is sufficient time from when the voltage is written to when the backlight is turned on. The backlight is turned on after reaching the halftone level. On the other hand, the display of the pixel corresponding to the mth scanning line is changed from the highest gradation level (255 gradation level) to the lowest gradation level (0 gradation level). In the pixel corresponding to the last m-th scanning line, since the period from when the voltage is applied to the pixel electrode until the backlight is turned on is as short as 5 ms, the luminance is as in B (m). The backlight is turned on before reaching the 0 gradation level. As described above, even in the case of the driving method according to the second comparative example for preventing blurring of the outline of the moving image, the pixel corresponding to the first scanning line that is closest to the first is effective, but is close to the mth. No effect can be obtained with the pixel corresponding to the last scanning line.

  FIG. 43 is a diagram showing the luminance response characteristics of the liquid crystal display element used in this comparative example. In the case of 256 gradations, the response time from the 0 gradation level to each gradation level, the response time from the 255 gradation level to each gradation level, and the response time from the intermediate gradation level to each gradation level are shown. . The final reached gradation level is taken on the horizontal axis, the response time is taken on the vertical axis, and the gradation level at the start point is shown as a parameter. The definition of the response time is shown in FIG. The vertical axis represents luminance in terms of gradation level, and the horizontal axis represents time. The luminance difference between the highest gradation level (255 gradation level in this case) and the lowest gradation level (0 gradation level) is assumed to be 100% until the luminance reaches ± 5% with respect to the final gradation level. Time is defined as response time. FIG. 43A shows a case of a response from a low gradation level (63 gradation levels) to a high gradation level (191 gradation levels) (rise). The response time is −5% of the 191 gradation level which is the final arrival gradation level, that is, the time until the gradation reaches the 178.25 gradation level. FIG. 43B shows a response from the high gradation level (191 gradation level) to the low gradation level (0 gradation level) (falling). The response time is the time required to reach + 5% of the 0th gradation level, which is the final reached gradation level, that is, the 12.75th gradation level.

  In the present invention, the response from the 0 gradation level to each gradation level is improved to 5 ms or less, but the response characteristic from the 255 gradation level is basically due to the relaxation process and is not improved. As shown in FIG. 43, the response is slow. In particular, the response from the 255 gradation level to the 0 gradation level is slow, and unless the period until the backlight is turned on is lengthened, the backlight is turned on before the luminance reaches the 0 gradation level. It is the cause.

[Embodiment 21]
The twenty-first embodiment is a driving method that solves the problem of the second comparative example. Compared with Embodiments 1 to 20, only the driving method is different. FIG. 45 shows an example of the time change of the potential of each wiring and electrode and the time change of the transmittance of the pixel of this embodiment.

  The difference from Comparative Example 2 is that a selection pulse is applied to all scanning lines and a voltage corresponding to the 0 gradation level is applied to all pixels before sequential scanning. In FIG. 45, the pulses are blacked out. Hereinafter, this pulse is referred to as an assist pulse.

  B (1) to B (m), VG (1) to VG (m), and VD are the pixel brightness, scanning line applied voltage waveform (selection pulse), and signal voltage line as in FIG. The applied voltage waveform is shown. As in the case of FIG. 42, the display is not changed in the (1) and (2) th frames. (3) After the display changes from the image A to the image B in the third frame, the display does not change again in the frames (4) and (5).

  The (1) th frame will be described. The brightness B (1) of the pixel corresponding to the first scanning line responds toward the brightness of gradation level 0 by the assist pulse, but immediately after the selection pulse is applied, a predetermined (image A Since the voltage (for displaying) is applied to the pixel electrode, the brightness immediately returns. The same applies to the luminance B (2) of the pixel corresponding to the second scanning line. The luminance B (m) of the pixel corresponding to the last scanning line has a sufficient time until the selection pulse is applied after the assist pulse is applied, so that the luminance reaches the 0 gradation level. Thereafter, the luminance responds toward a predetermined luminance (for displaying the image A) by applying the selection pulse. At this time, as shown in FIG. 4242, since the response from the 0 gradation level to each gradation level is as fast as 5 ms at the maximum, a predetermined (image A is displayed during the period until the backlight is turned on (5 ms). Can reach the brightness. As described above, since the backlight is turned on after all the pixels have responded, uniform display is possible in the (1) th frame. The same applies to the (2) th frame.

  (3) In the second frame, the display changes. As in the case of Comparative Example 2, in the (2) th frame to the (3) th frame, the display of the pixels corresponding to the first and second scanning lines starts from the highest gray level (255 gray level). It has changed to an intermediate gradation level. The luminance B (1) and B (2) of these pixels has a desired time (for displaying the image B) since there is sufficient time from when the voltage is written to when the backlight is turned on. The backlight is turned on after reaching the halftone level. On the other hand, the display of the pixel corresponding to the mth scanning line is changed from the highest gradation level (255 gradation level) to the lowest gradation level (0 gradation level). The period from when the assist pulse is applied to when the selection pulse is applied is the same as that of the (1) th and (2) th frames, and the luminance B (m) of the pixel is after the assist pulse is applied. Since there is a sufficient time until the selection pulse is applied, the luminance reaches the 0 gradation level. Thereafter, a voltage corresponding to the 0 gradation level which is a predetermined display (for displaying the image B) is applied to the pixel electrode by the selection pulse, but the luminance B (m) is already at the 0 gradation level. Has reached. Therefore, when the backlight is lit, all the pixels reach a predetermined luminance (for displaying the image B), and a predetermined display is possible.

  As described above, according to the twentieth embodiment, the response corresponding to the last scanning line closest to the m-th, which has a short period from the selection pulse to lighting, is always a fast response from the 0 gradation level. Therefore, unlike the comparative example 2, the display of the pixel corresponding to the last scanning line does not become defective, and a good display is possible. As described above, after applying a selection pulse in sequence and writing a predetermined voltage to all the pixel electrodes, the selection pulse is applied sequentially in the driving method in which the backlight is turned on to display a moving image clearly. Before the image is displayed, a satisfactory moving image display can be realized by applying a voltage corresponding to the 0 gradation level to all the pixels.

  In this embodiment, the voltage corresponding to the 0 gradation level is applied to and held by all the pixel electrodes by the assist pulse. However, depending on the liquid crystal display method, it is not always necessary to apply the voltage corresponding to the 0 gradation level. . FIG. 46R> 6 shows the response characteristics of the TN liquid crystal. In this case, a voltage corresponding to the 63 gradation level with the smallest maximum response time from the gradation to each gradation level is applied. Should. As described above, in accordance with the characteristics of the liquid crystal element, a voltage that minimizes the maximum response time from each state to each gradation level should be applied to the pixel during the assist pulse period. .

  In the IPS display mode, it is not always necessary to apply a voltage corresponding to the 0 gradation level to all the pixel electrodes by the assist pulse. By applying the same voltage to all of the pixel electrodes in advance before sequentially applying the pulse voltage to the scanning lines, the maximum response time for each gradation of the liquid crystal around each pixel electrode is shorter than the predetermined period. It should be in a state that will be in a state. For example, if the fixed period is 5 ms, the state may be a gradation close to 0, and if the fixed period is 6 ms, the state may be the gradation 0 to 63.

  Further, if such assist pulses are unified to a certain gradation, the same voltage may be applied to all the pixel electrodes. Further, the same voltage may be applied by making the potential of the pixel electrode equal to the potential of the common electrode. Such an assist pulse is applied by using the circuit configuration as shown in FIG. 2 to supply the same potential as the common electrode to the pixel electrode by using the assist pulse instead of the first selection pulse, and by the next selection pulse. This may be realized by supplying a potential for displaying an image to the pixel electrode, and a selection pulse applied to the common electrode 36 through the common electrode wiring 36 ″ using a circuit configuration as shown in FIG. Instead of using the assist pulse, the pixel electrode is supplied with the same potential as the common electrode, and then the pixel pulse is supplied with a potential for displaying an image by the selection pulse 102 during the same period. In addition, the assist pulse is applied by selecting all the scanning lines at once by setting the signal line potential to the 0 gradation level using the circuit configuration as shown in FIG. Etc., before applying the sequential selection pulse to the scanning lines, may be a previously all the pixel electrodes (to near 0 level) given by using the assist pulse to the circuit configuration can supply the potential.

It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 1 by this invention. It is a figure explaining the circuit structure of the conventional liquid crystal display device of this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the conventional liquid crystal display device. It is a figure explaining the cross section of the pixel vicinity in the conventional liquid crystal display device. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 1 by this invention. It is a figure explaining the principle of speeding up by a liquid crystal layer having an unevenness | corrugation. It is a figure explaining the effect of speeding up by a liquid crystal layer having an unevenness | corrugation. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 2 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 2 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 3 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 3 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 4 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 4 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 5 thru | or Embodiment 7 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 5 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 5 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 6 by this invention. It is a figure explaining the cross section (A-A 'cross section of FIG. 17) of the pixel vicinity in the liquid crystal display device of Embodiment 6 by this invention. It is a figure explaining the cross section (B-B 'cross section of FIG. 17) of the pixel vicinity in the liquid crystal display device of Embodiment 6 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 7 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 7 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 8 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 8 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 9 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 10 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 10 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 11 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 11 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 12 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 13 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 13 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 14 and Embodiment 17 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 14 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 15 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 15 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 16 by this invention. It is a figure explaining the cross section of the pixel vicinity in the liquid crystal display device of Embodiment 16 by this invention. It is a figure explaining the circuit arrangement pattern structure of the pixel vicinity in the liquid crystal display device of Embodiment 17 by this invention. It is a figure explaining the time change of the electric potential of each wiring and electrode in a liquid crystal display device of Embodiment 18 by this invention, and the time change of the voltage applied to a liquid crystal. It is a figure explaining the structure of the liquid crystal display device of Embodiment 19 by this invention. It is a figure explaining the time change of the electric potential of each wiring and electrode in a liquid crystal display device of Embodiment 19 by this invention, and the time change of the voltage applied to a liquid crystal. It is a figure explaining the time change of the electric potential of each wiring and the time change of the transmittance | permeability of a pixel in the liquid crystal display device of the comparative example 2 by this invention. It is a figure explaining the response characteristic of the liquid crystal in the liquid crystal display device of the comparative example 2 and Embodiment 21 by this invention. It is a figure explaining the definition of response time. It is a figure explaining the time change of the electric potential of each wiring in the liquid crystal display device of Embodiment 21 by this invention, and the time change of the transmittance | permeability of a pixel. It is a figure explaining the response characteristic of a TN liquid crystal element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Substrate, 3 ... Flattening film, 4 ... Color filter, 5 ... Black matrix, 6 ... Polarizing plate, 11 ... Pixel, 21 ... Electric force line, 22 ... Display part, 31 ... Signal line, 32 ... Scanning 33, first TFT, 33 'second TFT, 34 ... liquid crystal, 35 ... pixel electrode, 36 ... common electrode, 36' ... common electrode connection, 36 "... common electrode wiring, 81 ... insulating film, 82 ... protection Film: 85 ... Alignment film, 86 ... Second insulating film, 101, 102, 103 ... Selection pulse, 110 ... One cycle period

Claims (6)

A light source, a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate,
Corresponding to a plurality of scanning lines arranged on the first substrate, a signal line arranged intersecting the scanning line on the first substrate, and a region surrounded by the scanning lines and the signal lines And a pixel electrode disposed on the first substrate and corresponding to the signal line, and a common electrode disposed on the first substrate or the second substrate and corresponding to the pixel electrode A first active element disposed corresponding to an intersection of the scanning line and the signal line and electrically connected to the signal line, the scanning line, and the pixel electrode; and on the first substrate. And having an insulating film disposed,
During one cycle period for displaying one image, a pulse voltage is sequentially applied to the scanning lines, a potential for displaying an image is applied to all of the pixel electrodes, and held for a certain period. In the liquid crystal display device in which the light source is turned on,
The state immediately before the pulse voltage is applied to the liquid crystal of the pixel corresponding to the scanning line to which the pulse voltage is applied last in the one cycle period is the maximum value of the response time from that state to each gradation is the constant. A liquid crystal display device, characterized in that a state adjusting means is provided to make the state shorter than the period. The liquid crystal display device according to claim 1.
The liquid crystal display device, wherein the state adjusting means is means for applying the same voltage to all of the pixel electrodes before sequentially applying the pulse voltage to the scanning lines. The liquid crystal display device according to claim 1 or 2,
The liquid crystal display device, wherein the state adjusting means includes means for equalizing the potential of the pixel electrode and the potential of the common electrode before sequentially applying the pulse voltage to the scanning lines. A light source, a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate,
Corresponding to a plurality of scanning lines arranged on the first substrate, a signal line arranged intersecting the scanning line on the first substrate, and a region surrounded by the scanning lines and the signal lines And a pixel electrode disposed on the first substrate and corresponding to the signal line, and a common electrode disposed on the first substrate or the second substrate and corresponding to the pixel electrode A first active element disposed corresponding to an intersection of the scanning line and the signal line and electrically connected to the signal line, the scanning line, and the pixel electrode; and on the first substrate. And having an insulating film disposed,
During one cycle period for displaying one image, a pulse voltage is sequentially applied to the scanning lines, a potential for displaying an image is applied to all of the pixel electrodes, and held for a certain period. In a driving method of a liquid crystal display device in which a light source is turned on,
The liquid crystal state of the pixel corresponding to the scanning line to which the pulse voltage is applied last in the one cycle period is set so that the maximum response time from that state to each gradation is shorter than the predetermined period. A method for driving a liquid crystal display device, comprising: sequentially applying a pulse voltage to the scanning lines after adjusting the state. The method for driving a liquid crystal display device according to claim 4,
The method of driving a liquid crystal display device, wherein the state adjustment is performed by applying the same voltage to all of the pixel electrodes before sequentially applying the pulse voltage to the scanning lines. In the driving method of the liquid crystal display device according to claim 4 or 5,
The method for driving a liquid crystal display device, wherein the state adjustment is performed by equalizing a potential of the pixel electrode and a potential of the common electrode before sequentially applying the pulse voltage to the scanning lines.

Images