JPH04116687A - Liquid crystal color display device - Google Patents

Abstract

PURPOSE:To obtain a satisfactory display picture with a simple constitution by simultaneously controlling a set of red, green, and blue as a unit by signal lines, switches, and extents of delay. CONSTITUTION:First signal lines LH1 to LHM are divided to sets of red, green, and blue by three continuous lines, and every other picture element electrode in the vertical direction is shifted in the horizontal direction by a 1/2 picture element. The right and the left of every other picture element electrode in the vertical direction are alternately connected to first signal lines LH1 to LHM, and first signal lines LH1 to LHM are connected to three third signal lines 14R to 14B, to which red, green, and blue video signals are supplied, through switches MR1 to MBS with respect to individual colors. The extent of delay corresponding to the 1/2 picture element pitch is relatively given, and switches MR1 to MBS are simultaneously controlled with a set of red, green, and blue as the unit. Thus, the satisfactory display picture is obtained with the simple constitution.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a color liquid crystal display in which images are displayed by arranging liquid crystal display elements having red, green, and blue filters in an X-Y matrix. The present invention relates to a display device.

[Summary of the invention]

The present invention relates to a liquid crystal color display device, in which every three consecutive first signal lines are arranged as a set of red, green, and blue, and pixel electrodes are arranged every other vertically at a pitch of 1/2 pixel horizontally. At the same time, every other signal line in the vertical direction is connected alternately to the left and right to the first signal line, and these first signal lines are connected to each other via a switch to display red, green, and blue images for each color. Connects to three third signal lines to which signals are supplied, and relatively applies a delay amount corresponding to the pixel pitch to the red, green, and blue video signals supplied to these third signal lines, and By controlling the switches simultaneously in units of red, green, and blue, the number of stages of the scanning circuit that drives the switches is reduced, simplifying the configuration and reducing power consumption, resulting in a good display image. This is how it was done.

[Conventional technology]

For example, it has been proposed to display television images using liquid crystals (
(See Japanese Patent Laid-Open No. 59-220793, etc.).

That is, in FIG. 3, (1) is an input terminal to which a video signal is supplied, and the signal from this input terminal (1) is transmitted to switching elements MHI, MHl...MH, each consisting of, for example, an N-channel FET. , the vertical (Y-axis) direction line (first signal line) L H1+
L%□...Supplied to L. Note that m is a number corresponding to the number of pixels in the horizontal (X-axis) direction.

In addition, a horizontal scanning circuit (2
), a clock signal Φ+H+ ΦLM with m times the horizontal frequency is supplied to the horizontal scanning circuit (2), and drive pulse signals φ□, φ9□, etc. are sequentially scanned by the clock signals Φ, □, Φ2H. - φ□ is taken out from each output terminal of the horizontal scanning circuit (2) and supplied to each control terminal of the switching element M HI-M H@1. Note that the horizontal scanning circuit (2) has a low potential (VSS) and a high potential (
VOゎ) is supplied, and drive pulses of these two potentials are formed.

Further, each line LHI to L is provided with a switching element M formed of, for example, an N-channel FET.

M2. ...M□, M1□, M2□...M,,□,
. . . M, , M2, . . . One end of Mo is connected.

Note that n is a number corresponding to the number of horizontal scanning lines.

The other ends of the switching elements M, .about.M0 are connected to the target terminal (3) through liquid crystal cells C, . . . C2, . . . co, respectively. Note that t P Il is indicated by the broken line in the figure.
+P z+...Po substantially covers the pixel electrode.

Furthermore, a vertical scanning circuit (4
) is provided, a horizontal frequency clock signal ΦIV+ Φ2v is supplied to this vertical scanning circuit (4), and drive pulse signals φVI+ φv2...φv1 sequentially scanned by this clock signal ΦlV+ Φ2v are provided to the vertical scanning circuit (4). Gate lines (second signal lines) taken out from each output terminal in the horizontal (X-axis) direction Gv,, cv□・
...G□, and the gates iGv, ~Gv, , are connected to A to switch the switching elements M+I-M□ for each column in the X-axis direction (Mll ~M+,), (Mal-Mz,) ・-(
M...

~M71) are respectively supplied to the control terminals.

Note that VSS and vDD are supplied to the vertical scanning circuit (4) as well as to the horizontal scanning circuit (2).

That is, in this circuit, the scanning ports 8 (2), (4)
The lock signal Φ, as shown in FIGS. 4A and 4B.

Φ2H+ ΦI+/+ Φ2v is supplied. Then, from the horizontal scanning circuit (2), φ8. ~φ is output, and the vertical scanning circuit (4)
As shown in the same figure, φv1 to φ are divided into seven horizontal periods.
, 7 are output. Further, the input terminal (1) is supplied with a signal as shown in the same figure.

When φVII φ□ is output, switching elements MH1 and M11 to M1 . is turned on, and input terminal (1) -M )l I-L N I -M II
-C+ + - A current path of the target terminal (3) is formed, and the potential difference between the signal supplied to the input terminal (1) and the target terminal (3) is supplied to the liquid crystal cell CI+. Therefore, a charge corresponding to the potential difference due to the signal of the first pixel is sampled and held in the capacitance of this cell C1. The light transmittance of the liquid crystal is changed in accordance with this charge cap. The same thing is done sequentially for cells C+Z to C0, and when the next field signal is supplied, each cell C
The amount of charge in Il to C0 is rewritten.

In this way, the light transmittance of the liquid crystal cells C to C76 is changed corresponding to each pixel of the video signal, and this is sequentially repeated to display a television image.

Note that when displaying with a liquid crystal, AC drive is generally used to improve its reliability and extend its life.

For this reason, the input terminal ( ) is supplied with a signal obtained by inverting the video signal for each field or frame in displaying a television image, for example, as shown in the above diagram.

[Problem to be solved by the invention]

However, in this device, when trying to increase the number of horizontal pixels for the purpose of increasing image resolution, the horizontal scanning circuit (
2) The number of stages of the shift register increases, which increases the power consumption for driving (proportional to the number of stages), and the clock frequency increases due to the increase in the number of stages, which also increases power consumption (proportional to the frequency). ).

Further, the signals supplied to the input terminal (1) are φ□ to φ.

During the period of , the vertical signal is once charged to the wiring capacitance cH of the vertical signal line L)l through the switching elements M, , -M, , and then supplied to each liquid crystal cell, but as the number of stages increases and the clock frequency increases, , φ□ to φHi become shorter. Therefore, during the period of φ□, the vertical signal line L
In order to sufficiently drive (charge) the wiring capacitance CM of H with a video signal, the on-resistance of the switching element MH must be made considerably low, and therefore the size of the element (W/L)
will have to be made larger. On the other hand, if an attempt is made to increase the number of horizontal pixels, the number of switching elements MH also increases, and the number and size are large. , the proportion of the area occupied by the area becomes extremely large.

By the way, the applicant had previously filed a patent application for a similar device in 1973.
No. 8-214865 (see Japanese Unexamined Patent Publication No. 60-107862), Japanese Patent Application No. 59-221581 (Japanese Unexamined Patent Publication No. 61-198)
(See Publication No. 00086) and Japanese Patent Application No. 1986-232018
No. (see Japanese Patent Application Laid-open No. 6290692).

This application was made in view of these points.In addition to reducing power consumption by reducing the number of scanning circuit stages, the area occupied by switching elements on the chip is also reduced, resulting in a simple structure and good performance. This allows a display image to be obtained.

[Means to solve the problem]

The present invention provides a plurality of first signal lines (lines LHI to L, 1.) which are arranged in parallel in the vertical direction and each constitutes a set of red, green, and blue, and which are arranged in parallel in the horizontal direction. The double-defeat second signal line (gate line Gv+ to Gv, , ) arranged in
and are provided at the intersections of the first and second signal lines via selection elements CM11 to M□, respectively, and are provided at every other one in the vertical direction and shifted by 1/2 pixel pitch in the horizontal direction. and every other vertical direction, the first
The pixel electrodes (P
II-P, , , l) and a plurality of switches (horizontal switching elements M, lIM G+ + M m + ~M *
s + M e s + M m s ), and three third signals connected to each color of the first signal line through these switches and supplied with red, green, and blue video signals, respectively. Line ((!4R) (14G) (14B)
) and a delay means (circuit (IIRHIIG) (
IIG) (IIB) ) and the above switch to the above red,
This is a liquid crystal color display device characterized by having a switch driving means (horizontal scanning circuit (2)) that simultaneously controls green and blue sets as a unit.

[Operation] According to this, every three consecutive first signal lines are set as red, green, and blue groups, and the pixel electrodes are divided into 1/2 pixel in the horizontal direction for every other one in the vertical direction. They are staggered by a pitch and are alternately connected to the left and right to the first signal line every other signal line in the vertical direction, and these first signal lines are connected to red, green, and blue for each color via switches. The red, green, and blue video signals supplied to these third signal lines have relative delay amounts corresponding to the pixel pitch. By adopting a configuration in which the switches are simultaneously controlled in units of red, green, and blue pairs, the number of scanning circuit stages is reduced, power consumption is reduced, and the proportion of the area occupied by switching elements on the chip is reduced. It is possible to obtain a good display image with a simple configuration.

[Example] In FIG. 1, switching elements MI, ~M r+
For every other line L in the vertical direction, red (R), green (G), and blue (B) color fins LHI~Lots are made of opaque material such as aluminum. , and therefore the line L M I ” L Ns
are provided in a zigzag pattern along the boundaries of the pixel electrodes P, , -P-, and the switching elements M, , '=M
, 1. are provided toward the outside of this zigzag.

On the other hand, the input terminal (I
R) (IG) (IB) are provided, and signals from these input terminals (IR) (IG) (IB) are supplied to delay circuits (IIR) (IIG) (IIB), respectively, and the pixel electrode pH ~ The signal corresponding to the position of P7□ is delayed. These delayed signals are sent to the switch (12
R) (12G) (12B), and the signals from the delay circuits (IIR) (IIG) (IIB) are delayed for the signals corresponding to the positions of the pixel electrodes PII to P7 for each scanning line as described above. A delay circuit (13R) that performs (
13G) (13B) through switch (12R) (
12G) (12B). The signals from these switches (12R) (12G) (12B) are transmitted to the third signal lines (14R) (14G) (1
4B).

In addition, the above-mentioned horizontal switching elements MH1 to MH1 are arranged in groups of red, green, and blue (M * 1°) every three consecutive ones, and these switching elements MRI, MGIM
Signal lines (14R) (14G) (14B) of colors corresponding to m+-M*s, MGs, and Mis are connected. Moreover, these switching elements M, , M,
,,M,,~M11. .

The control terminals of MGS and MBs are commonly connected to each of the above-mentioned red, green, and blue groups.

In addition, a horizontal scanning circuit (2
1) is provided, and this horizontal scanning circuit (21) is provided with a clock signal Φ1. c, Φ2X is supplied,
Drive pulse signals φXl+φ8□...φ are sequentially scanned by the clock signals φIX+φ2X.

is taken out from each output terminal of the horizontal scanning circuit (21), and the switching elements Mll+ MGl+ Mll~Ml
sM (, 5, MB, respectively.
SS) and high potential (■.,) are supplied, and drive pulses of these two potentials are formed.

The rest of the circuit is constructed in the same manner as the circuit described in the description of the prior art.

Therefore, in this device, the number of stages of the shift register as the horizontal scanning circuit (21) is -the number of horizontal pixels, and the time width of the drive pulse signal φ8 is three times as large as φ□, so the switching elements MR, MG, and Ml are ■ The size (W/L) can be reduced to -M, and even if the number of horizontal pixels is tripled, the switching elements M, , M,
, M can be made approximately equal in area.

Furthermore, in this device, the positions of the red, green, and blue pixels are shifted in the horizontal direction, so when switching elements M, MG, and M are driven with the same drive pulse signal φ as described above, , there is a risk that the resolution in the horizontal direction will deteriorate due to the deviation between the signal position and the display position. Therefore, in this device, the input terminals (IR) (IG) (IB)
The signals from the respective delay circuits (IIR) (IIG)
(11B), and the signals corresponding to the positions of the pixel electrodes P to P- are delayed.

That is, in this device, for example, the red video signal is delayed by two clocks of the original drive pulse signal φ8, the green video signal is delayed by one clock, and the blue video signal is delayed by O clocks (no delay).

As a result, for example, when there is a red (R), green (G), and blue (B) video signal as shown in Fig. 2A, conventional equipment performs sampling as shown in Fig. 2B. While the signal at the position indicated by the circle mark was displayed,
In the above-mentioned apparatus, sampling as shown in FIG. 3C is performed. In this case, the delay circuit (IIR
) (IIG) (IIB) red, green,
The blue video signal is as shown in the same figure, and even if sampling is performed using the same drive pulse signal φX, sampling can be performed in the same way as in the conventional method.

Further, the delay circuits (13R), (13G), and (13B) correspond to the horizontal deviation of the pixel electrode pH to P7□ for each scanning line, and are provided with a delay amount of -φ8, for example. And switch (12R) (12G) (
12B) is switched every horizontal period, signals corresponding to the horizontal displacement of the pixel electrodes P II to P, , P, and A are supplied to the signal lines (14R), (14G, and 14B).

Thus, according to this device, the first signal line has three consecutive
Each book has red, green, and blue sets, and pixel electrodes are provided at every other vertical direction and shifted by 1/2 pixel pitch in the horizontal direction, and a first signal line is arranged at every other vertical direction. These first signal lines are connected alternately to the left and right for each color, and these first signal lines are connected to red, green,
By connecting to the three third signal lines that supply the blue video signal and simultaneously controlling each group as a unit, the number of scanning circuit stages is reduced, power consumption is reduced, and the chip In addition, the ratio of the area occupied by the snitching element is also reduced, and a good display image can be obtained with a simple configuration.

Note that this device is applied to a liquid crystal color display device in which a scanning circuit, a sampling means, etc. are integrated into an on-knob system together with a liquid crystal cell.

[Effect of the invention] According to this invention, the first signal line
These first signal lines connect to three third signal lines alternately on the left and right to the left and right signal lines, and these three third signal lines are supplied with red, green, and blue video signals for each color via switches and switches, respectively. The red, green, and blue video signals connected to the signal lines and supplied to these third signal lines are given a relative amount of delay corresponding to the pixel pitch, and the switch switches between the red, green, and blue pairs. By configuring the configuration to be controlled simultaneously in units of units, the number of scanning circuit stages is reduced and power consumption is reduced, and the area occupied by switching elements on the chip is also reduced, making it possible to achieve good display with a simple configuration. Now you can get images.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an example of a liquid crystal color display device according to the present invention, FIG. 2 is a timing chart for explaining the same, FIG. 3 is a block diagram of a conventional liquid crystal display device, and FIG. 4 is a timing chart thereof. It is a diagram. M is an element constituting a horizontal switching element and a selection element, L is a line as a first signal line, G is a gate line as a second signal line, P is a pixel electrode, C is a liquid crystal cell, (I
R) (IG) (IB) are input terminals to which red, green, and blue video signals are supplied, (IIRHIIG) (IIG) (
IIB) (13R) (13G) (13B) is a delay circuit, (12R) (12G) (12B) is a switch,
(14R) (14G) (14B) is the third signal line,
(21) is a horizontal scanning circuit, (3) is a target terminal, (
4) is a vertical scanning circuit.

Claims (1)

[Scope of Claims] A plurality of first signal lines arranged in parallel in the vertical direction and forming groups of red, green, and blue, respectively, every three consecutive signal lines, and a plurality of first signal lines arranged in parallel in the horizontal direction A second signal line is provided at the intersection of the first and second signal lines via selection elements, respectively, and is provided at every other one in the vertical direction and shifted by a 1/2 pixel pitch in the horizontal direction. pixel electrodes connected alternately to the left and right of the first signal line at every other pixel electrode in the vertical direction; a plurality of switches respectively provided corresponding to the first signal line; 3, which are connected to each color of the first signal line through the switches, and are supplied with red, green, and blue video signals, respectively.
the third signal line of the book, and the above red, green,
A liquid crystal display comprising a delay means for relatively giving a delay amount corresponding to a pixel pitch to a blue video signal, and a switch driving means for simultaneously controlling the switches in units of the red, green, and blue sets. Color display device.