JP5531393B2 - Display device - Google Patents

Description

  The present invention relates to a display device in which external light incident on a display surface is reduced.

  A self-luminous display or a liquid crystal display using a backlight as a light source is known as a display. In such an environment where the outside light is strong such as outdoors, the reflected light on the surface of the display is strong and the reflected light is observed strongly, so that the display contrast is lowered and the visibility of the display is poor. For this reason, an antireflection layer is provided on the display surface of a liquid crystal display used outdoors, and this antireflection layer is laminated on a polarizing plate to prevent display quality from being deteriorated. (See Patent Document 1)

JP2003-075603

Display with the antireflection layer, the antireflection layer, is not fully prevent the deterioration of display quality without sufficient anti-reflection, poor visibility. An object of the present invention is to provide a display device in which reflected light on the surface of the display device is reduced.

In order to solve the above problems, an aspect of the display device of the present invention includes a display panel on which a plurality of pixels are formed, and a predetermined height and width provided on the observation side of the display surface of the display panel. An external light shielding member that shields external light obliquely incident on the display surface of the display panel, and the external light shielding member is provided on the display panel. The light shielding wall is formed corresponding to a region between the adjacent pixels, and the light shielding wall includes a line segment connecting a midpoint between the lower ends of the adjacent light shielding walls and an upper end of the light shielding wall, and the display surface. Are formed so that the angle formed by the angle is between 82 ° and 85 ° .

  The display device of the present invention can reduce reflected and scattered light of external light, and can obtain excellent visibility under strong external light such as outdoors.

(First embodiment)
FIG. 1 shows an appearance of a display device according to the first embodiment of the present invention, and FIG. 2 shows a cross-sectional view of the display device shown in FIG. As shown in FIG. 1 and FIG. 2, the display device of this embodiment is disposed on the observation side of the display panel 1 provided with a polarizing plate on the observation side and the polarizing plate 6 on the observation side of the display device, includes a predetermined external light shielding member 2 having a plurality of light blocking walls are formed in a lattice shape having a height and width, and a backlight 4 arranged on the side opposite to the observation side of the display panel 1 Yes.

In this embodiment, for example, a liquid crystal display element is used as the display panel 1, and the liquid crystal display element is a liquid crystal panel 3 and a front polarizing plate disposed on the observation side (hereinafter referred to as the front surface) of the liquid crystal panel 3. 6, the side opposite to the observation side of the liquid crystal panel 3 (hereinafter, referred to as the back) provided with a rear-side polarizing plate 10 arranged on the.

The liquid crystal panel 3 is arranged such that the upper transparent substrate 7 on the front side and the lower transparent substrate 9 on the rear side face each other. One counter electrode 16 formed over the entire display area is formed on the inner surface of the upper transparent substrate 7 facing the lower transparent substrate 9. A plurality of pixel electrodes 12 facing the counter electrode 16 are formed on the surface of the lower transparent substrate 9 facing the upper transparent substrate 7. Regions of the pixel electrode 12 of the lower transparent substrate 9 and the counter electrode 16 of the upper transparent substrate 7 facing each other form a plurality of pixels 12a that are one display element, and these pixels 12a are arranged in rows and They are arranged in a matrix in the column direction.

An inner surface of the upper transparent substrate 7 is further formed in a corresponding inter-pixel region between the plurality of pixel electrodes 12 formed on the lower transparent substrate 9 to block transmission of light from the inter-pixel region. And black filters 13 and color filters 15R, 15G, and 15B formed in correspondence with the respective pixels 12a .

A plurality of thin film transistors (TFTs) 11 provided for each of the plurality of pixel electrodes 12 arranged in a matrix are formed on the inner surface of the lower transparent substrate 9. Connected to data line wiring .

And the upper transparent substrate 7 and the lower transparent substrate 9, on the counter electrode 16 and the pixel electrode 12 formed on the respective inner surfaces, are formed alignment film (not shown) is, substantially orthogonal to each other each of the alignment film After being rubbed in the direction, the liquid crystal layer 14 is sealed in a region surrounded by the upper transparent substrate 7, the lower transparent substrate 9, and the seal material 8.

The liquid crystal panel 3 formed in this manner, the upper transparent substrate 7 and the transmission normally white display color display TN of having a liquid crystal layer 14 in which liquid crystal molecules are substantially 90 ° twisted between the lower transparent substrate 9 This is an active matrix type liquid crystal display element.

The backlight 4 is a surface light source that emits uniform light to the back surface of the liquid crystal panel 3. Although not shown, the backlight 4 includes a light guide plate, LEDs arranged on the side or lower portion thereof, a cold cathode fluorescent lamp, and the like. It is made from a light source,.

  On the observation side of the observation side polarizing plate 6, a multilayer film for reducing surface reflection or a transparent film 22 having an antireflection layer 5 having fine irregularities formed on the surface is provided on the surface. On the top, an external light shielding member 2 is formed.

The external light shielding member 2 extends to a predetermined height in the normal direction of the substrate surface of the upper transparent substrate 7, and the light shielding walls having a width corresponding to the inter-pixel region of the liquid crystal panel 3 are respectively provided. These light shielding walls are formed in a lattice pattern on the observation surface side of the liquid crystal panel 3 so as to surround a region corresponding to a pixel. FIG. 3 is an enlarged plan view of a part of the display device according to the present invention as viewed from above. As shown in FIG. 3, the external light shielding member 2 includes an inter-pixel region 21 between adjacent pixel electrodes 12. In this case, it is arranged at a position that does not hinder the passage of the transmitted light 19. That is, the external light blocking member 2 is made to correspond to a so-called louver black mask 1 3 of the liquid crystal panel 3, by intersecting the row and column directions is obtained by forming a lattice shape. Case child-like external light shielding member 2, a photocurable resin, a thermosetting ink, the cold setting ink such as a material, a photolithography method, an inkjet printing, offset printing, is formed by screen printing or the like.

In this embodiment, the example in which the external light shielding member 2 is formed on the antireflection layer 5 formed on the observation side of the transparent film 22 is shown, but the present invention is not limited to this, The transparent film 22 may be formed separately, and the transparent film 22 may not be provided. That is, the external light shielding member 2 may be formed on the observation side polarizing plate 6. In this case, the external light shielding member 2 may be formed on the polarizing plate 6 before the observation-side polarizing plate 6 is attached to the upper transparent substrate 7, or the observation-side polarizing plate 6 may be formed on the upper transparent substrate 7. it may be formed after pasted to. Further, although not shown, the liquid crystal panel 3 may be disposed between the observation side polarizing plate 6 and the liquid crystal panel.

  In this display device, light from the backlight 4 is incident on the liquid crystal panel 3 and the intensity of transmitted light 19 incident on the liquid crystal panel 3 is changed by controlling the arrangement of liquid crystal molecules in the liquid crystal layer with an electric field. Display image or text information. The external light shielding member 2 reduces the reflected light on the surface of the observation-side polarizing plate 6 by shielding external light incident on the observation-side polarizing plate 6 from an oblique direction in all directions. Therefore, a display with high contrast and excellent visibility can be obtained.

  4 and 5 show an enlarged view of the external light shielding member 2 used in this embodiment. FIG. 4 is a plan view of one of the gratings surrounded by the light shielding walls of the lattice-shaped external light shielding member 2 as viewed from the normal direction of the liquid crystal panel, and FIG. 5 is a cross-sectional view thereof.

Efficiency of the external light shielding is determined by the height and spacing of the light shielding wall extending generally vertically from the surface of the antireflection layer of the transparent film 22. Therefore, as shown in FIGS. 4 and 5, the adjacent light-shielding wall 2a, the distance 2a W, the height of its and H, the light shielding angle is the incident angle of external light shielded by the light shielding wall θ To do. The light shielding angle theta, the observation-side upper end of the apex P and the adjacent contact shielding wall 2a of the light-shielding wall 2a, a line segment connecting the middle point C of the lower end between 2a, a bottom surface, when the angle formed by external light shielding From the height H of the member 2a and the interval W , θ is obtained by the following equation.
θ = arctan (H / (W / 2))
In order to evaluate the effect of shielding external light, the external light illuminance rate is expressed as follows: external light illuminance rate (%) = (illuminance with external light shielding) / (illuminance without external light shielding) × 100
Defining and becomes as is shown in Fig. 6 and light shielding angle θ and the external light illuminance ratio.

Ambient light illuminance ratio in the shielding wall 2a, 2a optical angle θ is 82 degrees to 85 degrees shielding of 6 is about 2%. Therefore, in this embodiment, so that the light angle θ shielding the external light illuminance ratio approximately 2% is obtained becomes 82 degrees to 85 degrees, and setting the height H and width W of the external light shielding member 2a.
That is, for example, a 2.6-inch wide QVGA liquid crystal panel 3 is used in the display device of this embodiment. In this case, the pixel pitch is 47 microns. Since the external light shielding member 2 is formed for each pixel pitch, the light shielding wall height H is set to 270 microns in order to set the light shielding angle θ to 85 degrees.

According to the display device of this embodiment, even in external light under a outdoor illuminance is 100,000 lux in fine weather days, with a child the optical angle θ shielding to 82 degrees to 85 degrees, external light panel surface The illuminance is reduced to 2000 lux and the contrast is 100.

As a comparative example, the relationship between the illuminance of external light and contrast is shown in FIG. 7 for a display device in which the external light shielding member 2 is not disposed. The display device has no external light blocking member 2 as is the contrast in an environment where external light is not incident shows the 600, the illuminance of external light is high, the contrast is lowered by reflection scattering light on the surface of the polarizing plate When the external light is 100,000 lux, the contrast is reduced to about 6. In contrast, the display device of this embodiment can obtain a contrast of 100 even under an external light of 100,000 lux, and the reduction in contrast due to the external light is greatly improved.

  As described above, since the external light shielding member 2 including the lattice-shaped light shielding wall 2a is arranged on the observation side of the liquid crystal panel 3, it is possible to prevent a decrease in contrast even under strong outdoor light outdoors, and the liquid crystal with high visibility. A display device can be provided.

FIG. 8 shows a first modification of the first embodiment. Display device according to this modification, by providing the function of the black mask in the external light shielding member 2 is the ash eliminating black mask.

  The first modification differs from the first embodiment only in that a black mask is not formed in the inter-pixel region 21 between the pixel electrodes 12, and the other structure is the same as the first embodiment. The same members are denoted by the same reference numerals and description thereof is omitted.

  According to the first modified example, since the black mask is not formed, the number of manufacturing steps can be reduced.

  Further, FIG. 9 shows a second modification of the first embodiment. In this second modification, the external light shielding member 2 has a structure in which the four pixel electrodes are surrounded by a lattice-shaped light shielding wall 2a as a unit. This second modification differs from the first embodiment only in that the external light shielding member 2 includes a light shielding wall that surrounds the four pixel electrodes as a unit, and the other structure is the same as that of the first embodiment. Therefore, the same members are denoted by the same reference numerals and description thereof is omitted.

  According to the second modification, the lattice-shaped light shielding wall 2a surrounds a plurality of pixels and is formed so as to correspond to the inter-pixel electrode portion between the pixel electrodes 12, so that the lattice-shaped light shielding wall 2a The spacing is widened, making it easy to manufacture a lattice louver on the antireflection layer provided on the polarizing plate.

In the first embodiment, the liquid crystal display device is a color display TN type for transmissive normally white display. However, the present invention is not limited to this, and can be applied to liquid crystal display devices of all types.

  Furthermore, even if the antireflection layer 5 of the transparent film 22 disposed on the polarizing plate 6 is not provided, a practically sufficient display quality can be obtained by the external light shielding effect of the external light shielding member 2.

(Second Embodiment)
FIG. 10 shows a second embodiment. The second embodiment is different from the first embodiment only in that a color organic EL panel is used instead of the liquid crystal panel, and the other components are the same as those of the first embodiment. Are denoted by the same reference numerals, and description thereof is omitted.

  In the display device according to the second embodiment, the external light shielding member 2 is disposed on the observation side of the color organic EL display panel 24.

The organic EL panel 24, the organic EL substrate 25 on the TFT11 and the pixel electrode 12 are arranged in a matrix, each color of the organic EL layers 28R, which is a light emitting material thereon, 28G, 28B, the single film-like Transparent counter electrodes 16 are sequentially stacked. The transparent protective substrate 26 facing the organic EL substrate 25 is bonded by a seal 31 surrounding the outer periphery of the substrate. The pixel electrode 12 and the counter electrode 16 form a plurality of pixel areas in a region opposed, 28R is an organic EL layer for each of the pixel area portion, 28G, 28B are filled respectively.
The organic EL panel 24 is an active matrix system having TFTs 11, and the TFTs 11 provided on the respective pixel electrodes 12 are connected to gate line wirings and data line wirings not shown. A transparent film 22 on which the quarter-wave retardation plate 27, the observation-side polarizing plate 6, and the antireflection layer 5 are formed is sequentially bonded to the observation-side surface of the transparent protective substrate 26.

  Further, an external light shielding member 2 is formed on the surface of the antireflection layer 5 of the transparent film 22 so as to correspond to an inter-pixel region between adjacent pixel electrodes 12.

In the organic EL panel 24, when a current is applied to the pixel electrode 12 from the TFT 11 , the organic EL layer emits light itself, and display is performed by the emitted light 19 from the observation side surface of the organic EL panel 24.

External light shielding member 2, as well as optimal external light shielding effect of the first embodiment can be obtained, is set to the interval of the light-shielding wall shielding angle θ is 82 degrees to 85 degrees and the height Yes.

Also in self-light device, such as an organic EL panel 24, by on the observation side of the polarizing plate provided rating child-like external light shielding member 2, similarly to the display device shown in the first embodiment, the external light Thus, the influence of the reflected light 18 on the surface of the observation-side polarizing plate 6 can be reduced to prevent a decrease in contrast, and excellent visibility can be obtained.

  In the second embodiment, the transparent film 22 on which the antireflection layer 5 is formed is provided on the observation side of the observation side polarizing plate 6. However, the present invention is not limited thereto, and the transparent film 22 on which the antireflection layer 5 is formed is provided. However, the observation-side polarizing plate 6 may be provided with the external light shielding member 2, and in this case, a practically sufficient display quality can be obtained.

(Third embodiment)
FIG. 11 shows a cross section of a display device according to the third embodiment. In the display device of this embodiment, the external light shielding member 2 formed into a sheet is disposed on the observation side of the liquid crystal panel 3, and the first is only in that the external light shielding member sheet 29 formed into a sheet is disposed. Unlike the first embodiment, the other structure is the same as that of the first embodiment, so the same members are denoted by the same reference numerals and the description thereof is omitted.

The external light shielding member 34 of this embodiment forms a lattice-shaped light shielding wall between a pair of transparent films 30 and 31, and a transparent resin 32 is provided in a region surrounded by the light shielding wall and the transparent films 30 and 31. And the pair of transparent films 30 and 31 are bonded together to form a single sheet.

  And the transparent film 22 which formed the antireflection layer 5 in the observation surface side of one transparent film 30 of this sheet-shaped outside light shielding member sheet | seat 29 is laminated | stacked and formed.

  According to the display device of the third embodiment, since the external light shielding member 2 is formed into a sheet and used as the external light shielding member sheet 29, handling is facilitated and productivity can be improved.

In the display device of the third embodiment, the transparent film 22 to form an antireflection layer 5, and the observation-side surface of the external light blocking member sheet 29, and the opposite surface, at least one surface of the By providing in, the fall of visibility by external light can be improved more.

  Further, even if the transparent film 22 on which the antireflection layer 5 is formed is not provided, a practically sufficient display quality can be obtained by the external light shielding effect of the external light shielding member sheet 29.

As the external light shielding member in the first and second embodiments described above, an example in which the light shielding wall is formed in a lattice shape extending linearly in the row and column directions has been shown. Without limitation, an external light shielding member having a honeycomb-shaped light shielding wall 33 as shown in FIG. 12, or a lattice-shaped light shielding wall 34 shown in FIG. 13 which is shifted by half a lattice between odd rows and even rows. You may use the external light shielding member with.

1 is an external view showing a display device provided with an external light shielding member according to a first embodiment. Sectional drawing of the display apparatus which concerns on 1st Embodiment. The top view which expands and shows a part of display apparatus which concerns on 1st Embodiment. The top view which expands and shows a part of external light shielding member. Sectional drawing which expands and shows a part of external light shielding member. The figure which shows the change of the external light illumination rate with respect to a light-shielding angle. Diagram showing the relationship between the illuminance of outside light and the contrast in the comparative example not of the ambient light shielding member. Sectional drawing which shows the 1st modification in 1st Embodiment. The fragmentary top view which shows the 2nd modification in 1st Embodiment. Sectional drawing which shows the display apparatus which concerns on 2nd Embodiment. Sectional drawing which shows the display apparatus which concerns on 3rd Embodiment. The top view which shows the external light shielding member which has a honeycomb-shaped light shielding wall. The top view which shows the external light shielding member which has the grid | lattice-like light-shielding wall which shifted half a lattice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display panel 2 External light shielding member 3 Liquid crystal panel 4 Backlight 5 Antireflection layer 6 Observation side polarizing plate 7 Upper transparent substrate 8 Sealing material 9 Lower transparent substrate 10 Polarizing plate 11 TFT
12 pixel electrode 13 black mask 14 liquid crystal layer 15R color filter red 15G color filter green 15B color filter blue 16 counter electrode 17 external light 18 reflected scattered light 19 transmitted light 21 inter-pixel region 22 transparent film 24 organic EL panel 25 organic EL substrate 26 Transparent protective substrate 27 Phase difference plate 28R Red EL layer 28G Green EL layer 28B Blue EL layer,
29 Outside light shielding member sheets 30, 31 Transparent film substrate 32 Transparent resin 33 Honeycomb shaped outside light shielding member 34 Half-lattice outside light shielding member C Midpoint H at the lower end between adjacent louvers Height P of outside light shielding member Observation interval θ shielding angle Shah side louver upper vertex W external light blocking member

Claims (13)

A display panel in which a plurality of pixels are formed;
A grid-shaped light shielding wall having a predetermined height and width is provided on the viewing side of the display surface of the display panel, and shields external light incident obliquely on the display surface of the display panel. An external light shielding member to be
With
The external light shielding member is formed corresponding to a region between adjacent pixels of the display panel,
The light shielding wall has an angle between a line segment connecting a midpoint between the lower ends of the adjacent light shielding walls and the upper end of the light shielding wall and the display surface of 82 ° or more and 85 ° or less. Formed,
A display device characterized by that. The display panel includes at least one of the one substrate on which electrodes are formed, it is opposed placed on the one substrate, and the substrate of the other of the plurality of electrodes are formed, and one of the substrate such as the other substrate And a liquid crystal panel in which the plurality of pixels are formed by regions where the electrodes formed on the one substrate and the other substrate face each other. The display device according to claim 1.   The display device according to claim 1, wherein the light shielding wall of the external light shielding member is formed so as to surround each of the plurality of pixels. The external light shielding member is formed on the extending in the height predetermined in the normal direction of the display surface of the display panel, the light shielding wall having a width corresponding to interpixel regions of the display panel is shaped rated child The display device according to claim 1, wherein the display device is a display device. A polarizing plate disposed on the observation side of the display surface of the display panel;
The display device according to claim 1, wherein the external light shielding member is formed on the observation side of the polarizing plate. Further comprising a transparent film disposed on the observation side of the polarizing plate and having an antireflection layer formed on the observation side;
The display device according to claim 5, wherein the external light shielding member is formed on the antireflection layer of the transparent film.   The display device according to claim 1, further comprising a backlight on a side opposite to the observation side of the display surface of the display panel.   In the display panel, a substrate on which a plurality of electrodes are formed, an organic EL layer made of a light emitting material, and a transparent counter electrode are sequentially stacked, and the plurality of pixels are formed by regions facing the respective electrodes. The display device according to claim 1, comprising an organic EL panel. A quarter-wave retardation plate disposed on the observation side of the counter electrode of the organic EL panel;
A polarizing plate disposed on the observation side of the quarter-wave retardation plate,
A transparent film disposed on the observation side of the polarizing plate and having an antireflection layer formed on the observation side;
Further comprising
The display device according to claim 8, wherein the external light shielding member is formed on the antireflection layer of the transparent film.   The external light shielding member includes the light shielding wall formed in a lattice shape between the first transparent film and the second transparent film that are disposed to face each other, the lattice-shaped light shielding wall, and the first transparent film. The display device according to claim 1, comprising an external light shielding sheet formed of a transparent resin filled in a region surrounded by a film and the second transparent film. .   The display device according to claim 10, wherein the external light shielding sheet has an antireflection layer formed on at least one of the observation side and the opposite side of the observation side.   The display device according to claim 1, wherein the external light shielding member includes the honeycomb shaped light shielding wall.   12. The display device according to claim 1, wherein the external light shielding member includes a grid-shaped light shielding wall that is shifted by a half-grating from each other in an odd-numbered row and an even-numbered row.

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