JPH06342156A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To make it possible to drive this device with a simple driving circuit and to obtain high-grade reproduced images by adopting delta arrangement. CONSTITUTION:Picture elements are arranged repetitively in specified order with three colors; red R, green G and blue B as one period in odd lines and are arranged with deviation by 1.5 picture element pitch from the arrangement of the odd lines in even lines. Scanning electrodes 11 or signal electrodes 16 are formed zigzag in such a manner that the amplitude attains half the picture element pitch. These electrodes are connected to the picture elements of the same color alternately on the left and the right on the outer side of zigzag projecting parts of the same signal lines. The timing of sampling is shifted by the time corresponding to 1.5P (P=effective horizontal scanning time/number of horizontal picture elements) in the odd lines and the even lines. The signals to drive the signal electrodes are delayed by 1.5P only in either case according to whether selected scanning electrodes are the odd number place or the even number place in order to shift the timing of the sampling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to picture elements of a color liquid crystal display device, color arrangement of a coloring means, and electrical control.

[0002]

2. Description of the Related Art A color liquid crystal display device will be described. The color liquid crystal display device has a large number of picture elements arranged in a dot matrix and a coloring means arranged corresponding to each picture element. By applying an image signal corresponding to the color corresponding to each picture element and controlling it, it is possible to display an arbitrary color image which is additively mixed by the same principle as the color CRT and which includes an intermediate color. For more information on liquid crystals, refer to "Basics and Applications of Liquid Crystal Electronics" edited by Sasaki (Ohmsha, 1979).

The operation modes of the liquid crystal display device include twisted nematic (TN) and guest host (G).
H), there are many modes such as phase transition, and the present invention can be applied to any of them, but TN and GH give preferable results. The GH uses a black pigment and operates as a so-called black shutter.

Normally, the additive three primary colors are selected as the colors of the coloring means. As the coloring means, an interference filter or an inorganic or organic dye or pigment color filter is used. The coloring means may be provided on the outer surface or the inner surface of the substrate forming the liquid crystal display device. In the latter case, it may be provided above or below the signal electrode, scanning electrode, pixel electrode or common electrode.

In the color liquid crystal display device, only the spectrum region of one of the three primary colors is used in the spectrum of the incident light, and the remaining components are absorbed by the coloring means. Further, in the case of the liquid crystal operation mode using a polarizing plate, the amount of light that can be used is further halved, so that it becomes very dark in the reflection type mode in which no illumination means is provided. For this reason, as a lighting means, a light source such as an incandescent lamp, a fluorescent lamp, and an EL device is provided, or means for guiding ambient light to the back surface of the liquid crystal display device is provided. In the case of application to portable equipment, improvement of luminous efficiency of a light source is an important point because power source capacity is severely restricted.

To faithfully reproduce a video signal, a large number of scanning lines are required. For example, consider a liquid crystal panel for a color television. In the NTSC system of television broadcasting,
The band of the luminance signal (Y signal) is 4 MHz, while
The bands of the I signal and the Q signal, which are hue signals, are 1.
They are 5 MHz and 0.5 MHz. Since the 0.5 MHz sine wave includes a wave of 26.5 cycles in one effective horizontal scanning period (53 μsec), the horizontal resolution is equivalent to 53 when counted as one light and one dark. According to Canon's theorem, if sampling is performed at a frequency twice the highest frequency of the original signal, the information contained in the original signal should not be lost, but the signal sampled in this way It is hard to say that the image obtained when the image is reproduced as is is visually faithful to the original signal due to the influence of aliasing. Visually satisfying is when sampling is performed at a frequency of 3 times or more the highest frequency. Therefore, to reproduce a 0.5 MHz video signal, if the number of picture elements of the same color on the same horizontal line is 80 or more, the information of the original signal can be reproduced almost faithfully.

In a liquid crystal display device having a large number of picture elements, one of the following three methods is usually used to individually control each picture element.

(1) Simple Matrix As shown diagrammatically in FIG. 6A, a stripe-shaped electrode group is provided on each of two opposing substrates, and they are laminated so that they are orthogonal to each other to form a liquid crystal display device. . A row selection signal is sequentially applied to the row electrodes (scanning electrodes) SL, SL provided on one substrate. Image signals are applied to the column electrodes (signal electrodes) DL and DL provided on the other substrate in synchronization with the row selection signal. The overlap region (indicated by diagonal lines) of the row electrode SL and the column electrode DL serves as a pixel, and the liquid crystal sandwiched between the two electrodes responds to the potential difference between the two.

In this method, since the liquid crystal responds to the effective value, the number of scanning lines cannot be increased so much in terms of crosstalk and dynamic range.

Multiple matrices have been devised to overcome these limitations. This is a method of increasing the number of picture elements in the scanning electrode direction without increasing the number of scanning electrodes by deforming the signal electrodes of the simple matrix. (See Sasaki ed., "Basics and Applications of Liquid Crystal Electronics" (Ohm Co., 1979)) Currently, dual matrix and quadruple matrix liquid crystal display devices have been commercialized or prototyped. In the double matrix schematically shown in FIG. 6B, the number of scan electrodes SL is kept the same as the conventional one, while the number of signal electrodes DL is doubled and the number of picture elements (shown by diagonal lines) is doubled. Thus, two adjacent rows of picture elements are simultaneously scanned.

In the multi-matrix, since the shape of the signal electrode is complicated and a portion having a narrow wiring width is formed, the wiring resistance tends to increase. If the wiring resistance cannot be sufficiently reduced only by the transparent conductive film, metal wiring is used together. The use of metal wiring reduces the effective pixel area and darkens the screen. Further, when the multiplicity is increased, the area of the wiring portion becomes relatively large and the effective pixel area decreases.

The following two methods have been developed which are effective when the number of picture elements is large.

(2) Addition of non-linear element A varistor, Back- is used as an active element for each picture element.
To-Back diode, MIM (Metal / In
This is a method of suppressing crosstalk by adding a non-linear element such as a sulator / metal) element. As schematically shown in FIG. 6C, a picture element electrode PE corresponding to each picture element is provided, and each picture element electrode PE is connected to a signal electrode DL via a non-linear element NL. The scanning electrodes SL, SL are provided on the opposing substrates in a direction perpendicular to the signal electrodes DL. The picture element is located in a portion where the picture element electrode PE and the scan electrode SL overlap each other, as indicated by the diagonal lines.

(3) Addition of switching element In this method, a switching transistor is added as an active element to each picture element and driven individually. As schematically shown in FIG. 6D, a picture element electrode PE corresponding to each picture element is provided and connected to the signal electrode DL via the switching element SW. The scan electrodes SL, SL are provided in the direction orthogonal to the signal electrodes DL and connected to the gate of the switching element SW. On the other hand, the common electrode CE is provided on the opposing substrate. The picture element is composed of a picture element electrode PE and a common electrode CE, as indicated by diagonal lines.
It is in the overlapping part with. The liquid crystal itself is a capacitive load, but a storage capacitor is added if necessary.
A drive voltage is applied during the selection period, the capacitor is charged, and it is held during the non-selection period. The liquid crystal itself is also a capacitive load, and the storage capacitor can be omitted if its own constant is sufficiently larger than the driving repetition period.

As the switching transistor, a thin film transistor or a MOS-FET formed on a silicon wafer is used.

Although not specifically shown in the above description, in the color liquid crystal display device, a color filter is arranged corresponding to each picture element.

The present invention can be applied to any of the above methods.

Next, the color array which is the object of the present invention will be described. Color liquid crystal display devices using liquid crystal have already been disclosed in, for example, Japanese Patent Laid-Open Nos. 49-57726 and 49-49.
-74438 gazette etc. are disclosed. The former discloses an XY matrix display device using a striped color filter of three primary colors, and the latter discloses a matrix display device in which a thin film transistor (TFT) is provided for each pixel electrode. In these examples, it is described that a color filter having three primary colors in a stripe shape or a mosaic shape is used, and the method of arranging the three primary colors in the color arrangement is not specifically mentioned. Further, in the conventional TFT matrix display substrate, the signal electrodes and scan electrodes connected to the vertical and horizontal rows of picture elements are straight lines, and all the picture element electrodes have corresponding signal electrodes and scan electrodes. Were arranged on the same side of the intersection.

Conventional color arrays (see FIG. 7) are roughly divided into stripes and mosaics. The former striped color array is an array of strip-shaped picture elements arranged in parallel, and has vertical stripes (Fig. 7A) and horizontal stripes (Fig. 7A).
B) The latter is a mosaic color array in which square or rectangular picture elements are arranged in a grid pattern.
9 picture element stairs (Fig. 7C), 6 picture elements vertically (Fig. 7D), 6 picture elements horizontally
There are picture element types (FIG. 7E), four picture element types (FIG. 7F), etc., and further variations thereof are conceivable. In FIG. 7, the symbols R, G, and B respectively indicate the additive three primary colors red, green, and blue, and the parentheses {indicate the basic cycle of the pattern of arrangement of the three colors (R, G, B). . The 6-pixel type and the 4-pixel type are proposed by the present inventors. (Japanese Patent Application Sho 5
(8-242548, etc.) If the number of picture elements is sufficient to faithfully reproduce the video signal, the color arrangement of the picture elements does not affect the quality of the reproduced image. If is not large enough, the quality of the reproduced image is significantly affected by the color arrangement. In the case of a striped color array, the vertical stripe does not require color switching of drive signals, and the horizontal stripe has the advantage that color switching can be performed for each scanning line in front of the analog line memory. The spatial resolution in the direction perpendicular to the stripe is as bad as 3 picture elements, and has a drawback that moire fringes are likely to occur. Further, in terms of visual characteristics, when the white balance is satisfied, the brightness of blue is low and it looks very dark, so the blue line appears as a black striped pattern and the image quality is impaired. On the other hand, in the case of a mosaic color array, 9
In the picture element staircase type, picture elements of the same color are diagonally connected in a staircase pattern, but the spatial resolution in the direction perpendicular to the series is 3 /
√2, and although the above-mentioned drawbacks are somewhat reduced, it is necessary to switch the color of the video signal for each signal electrode and each scanning electrode.

In order to solve such a drawback, the inventors of the present invention have proposed 6-pixel type and 4-pixel type color arrays in the above application. In the 6-pixel type, the blue line becomes zigzag and the striped pattern becomes less noticeable. In the 4-pixel type, the green pixels are arranged in a checkered pattern, the spatial resolution is 1 pixel in both vertical and horizontal directions, and √2 pixels in the worst diagonal direction, and the anisotropy is considerably small. Since the blue picture elements are arranged in a scattered manner, dark lines will not occur. Vision has the characteristic that the spatial resolution with respect to brightness (brightness) is high, but the spatial resolution with respect to hue is not so high. Contribution to brightness is that green is the largest in red, green, and blue, so the green picture element As long as the signal (Y signal) is reproduced faithfully, the red and blue picture elements have no spatial degradation even if the spatial resolution is only half that of green.

However, in the mosaic color array,
Although the resolution and the reproduced image quality are improved, the picture element drive circuit is complicated. That is, as described below, since the color of the picture element driven by the same signal electrode is two or three, it is necessary to switch the color of the video signal.

FIGS. 8A and 8B are wiring diagrams when a liquid crystal is driven by a thin film transistor (TFT) panel having a conventional mosaic pixel array. All pixel electrodes are arranged on the same side of the intersection of the corresponding signal electrode and scan electrode. TF is applied to the pixel electrodes arranged in a mosaic pattern (not shown).
The drain electrodes of T1, 1, ... And storage capacitors provided as necessary are connected. In the figure, capacitors 2, 2, ... Are equivalent circuits representing the capacitance of the liquid crystal, and the tips of the arrows are commonly connected to a common electrode. Each scan electrode (gate line) 3 is a TFT lined up horizontally
It is connected to the gates of 1, 1, ... In addition, each signal electrode (data line) 4 is composed of vertically arranged TFTs 1, 1,
It is connected to the source electrode of. The gate driver 5 composed of a shift register scans the scan electrodes 3, 3, ... Sequentially and cyclically by a scan pulse (horizontal synchronizing signal H), and the TFT connected to the selected scan electrode 3.
The image signals applied to the signal electrodes in synchronization with the signals 1, 1, ... Are applied to the picture element electrodes (not shown) and the capacitors 2, 2, ... Through the TFTs 1, 1 ,. The capacitors 2, 2, ... Hold the voltage to be applied to the liquid crystal even while the TFTs 1, 1 ,.
If the time constant of the liquid crystal is sufficiently larger than the scanning cycle, the storage capacitor need not be provided.

In the conventional mosaic color array,
Two-color or three-color picture elements are connected to the same signal electrode 4, signals (R, G, B) corresponding to each color are applied to the signal electrode 4, while the scanning electrodes 3, 3, ... By scanning to, each picture element selects only the corresponding signal. Therefore, a circuit that periodically switches the signals (R, G, B) is required. Therefore, in FIG. 7A, the R, G, and B video signals are input to the analog line memory 6, respectively, and the video signals of the respective colors sampled by the analog line memory 6 are provided in the color switching circuits 7 provided for the respective signal electrodes 4. Input to and select the signal corresponding to the color array. Here, the analog line memory 6 samples the color video signal R, G, or B and outputs the signal in synchronization with the scan electrodes. In FIG. 7B, the video signal is sent to the analog line memory 6. A so-called delta arrangement is disclosed in the color liquid crystal display device disclosed in JP-A-59-9636. That is, the rows of color filters arranged in order of red, green, and blue are arranged adjacent to each other with a shift of 0.5 cycle. (See FIGS. 2A and 2B of the same publication) As a result, the resolution of the image is improved. However, it is desirable that the driving circuit of the delta liquid crystal display device can be further simplified.

An object of the present invention is to provide an array pattern of picture element electrodes which can be driven by a simple driving circuit and which provides a reproduced image of high quality.

[0025]

As described above, in the conventional color liquid crystal display device, the image resolution is low,
The display quality was also poor. There is also a problem that the drive circuit is complicated.

[0026]

Therefore, the present inventors have
It has been found that this objective can be achieved by employing a delta arrangement.

According to the present invention, in a color liquid crystal display device in which corresponding picture elements of red, green and blue colors are linearly arrayed periodically, the picture elements are three lines of red, green and blue in odd lines. The scan lines or the signal electrodes are repeatedly arranged in a fixed order with one cycle of the color, and are arranged with a shift of 1.5 pixel pitch with respect to the arrangement of the odd lines in the even lines.
It is characterized in that it is formed in a meandering manner so that its amplitude is 1/2 of the picture element pitch, and that it is alternately connected to the picture elements of the same color outside the meandering convex portion of the same signal line.

[0028]

According to the present invention, the image resolution is improved and the display quality is improved by using the delta arrangement of the picture elements as in the means for solving the above problems. Also,
Since the electrode drive circuit is also simple, it is possible to significantly reduce the influence of wiring resistance.

[0029]

The present invention will be described in detail below with reference to the drawings.

In the present invention, a delta arrangement is adopted as the color arrangement. It is known that this delta array has the smallest direction dependence of spatial resolution. That is,
By adopting the delta arrangement, it becomes possible to realize a high-quality reproduced image. The color array of the color filter and the array of picture elements corresponding to the color array are made into a delta array.
In the delta arrangement, the three colors red, green and blue are periodically arranged linearly, and the adjacent linear arrangements are offset from each other by half a period in the parallel direction. 1A and 1B show the case where the shape of the picture element is rectangular and hexagonal, respectively. The center of gravity of each color is arranged in an isosceles triangle. If the ratio of the height of the triangle to the base is √3 / 2, the position of the center of gravity of each picture element becomes an equilateral triangle. If you take out only the picture elements of the same color, they are arranged in hexagonal symmetry. Further, the columns of the same-colored picture elements are arranged every other row in the direction perpendicular to this linear arrangement, and the columns of the same-colored picture elements in the vertical direction are arranged in the horizontal direction.
It has an interval of 1.5 pitches (half cycle) and is vertically displaced by one picture element.

In the present embodiment, in order to simplify the picture element drive circuit, for example, as shown in FIG. 1C, the signal electrodes are cranked or curved so that the amplitude is 1/2 of the picture element pitch. The picture elements (B in FIG. 1C), which are meandered in the meandering direction and are driven by the same scanning electrode, are arranged alternately on the left and right. That is, the positions of the centers of gravity of the picture elements to which the video signals are supplied by the same signal electrode are arranged alternately on the left and right by 1.5 picture element pitch (half cycle) for each row. According to such a configuration, since it is necessary to apply only the video signal of the same color to the same signal electrode, it is not necessary to switch the color video signal of the analog line memory, and the driving circuit becomes very simple. It also has features.

Although the delta array was initially adopted in a color CRT belonging to a technical field different from that of the present invention,
The reason for this is that the electron gun having the largest diameter should be arranged on the thin neck as much as possible, and the present invention was adopted from another technical requirement. Nowadays,
Since a high-performance electron gun can be obtained, it is rarely used for a home color TV.

Next, an embodiment of a color liquid crystal display device to which a switching element is added will be described. FIG. 2A is a plan view schematically illustrating an example of a thin film transistor (TFT) that is a switching element, and FIG. 2B is a cross-sectional view taken along the line AA. The TFT is formed by sequentially patterning and stacking a scanning electrode 11, a gate insulating film 12, a semiconductor film 13, a signal electrode 14, and a drain electrode 15 on a transparent insulating substrate 10 such as glass. A pixel electrode 16 and a storage capacitor (not shown) provided as necessary are connected to the drain electrode 15. As a thin film forming method, a vacuum evaporation method, a sputtering method, a CVD method, a plasma CVD method, a low pressure CVD method, or the like is used, and patterning is performed by a shadow mask or photolithography technique. A light shield and an alignment film are further provided to drive the liquid crystal on the substrate on which the TFT is formed. When an n-type semiconductor is used as the semiconductor film 13, the scanning electrode 11
When a positive voltage is applied to, an electron storage layer is formed at the interface of the semiconductor film 13 on the gate insulating film 12 side, and the resistance between the signal electrode (source electrode) 14 and the drain electrode 15 is modulated.

One feature of the present invention is that the signal electrodes are meandered to the left and right, and the picture elements driven by the same signal electrode are synchronized with the meandering and are alternately distributed to the left and right to arrange the picture element array for each scanning line. 1.5 Pixel pitch shift Delta array is realized. With such a configuration, the colors of the picture elements driven by the same signal electrode are the same, and switching is unnecessary. 3A and 3B show an example of the connection pattern. A is an example where the shape of the picture element is a rectangle, and B is an example where it is a hexagon. In the figure, for simplicity, the insulating film 12 at the intersection of the semiconductor film 13 and the signal electrode 14 and the scanning electrode 11 is shown.
Was omitted.

The gist of the present invention is that the position of the center of gravity of each picture element is in a delta arrangement, and the shape of the picture element is not limited to a rectangle and a hexagon. The patterns shown in FIGS. 3A and 3B are examples of patterns in which only the scan electrodes are branched to form a transistor, but only the scan electrodes or both the signal electrodes and the scan electrodes are branched to form a transistor. It is also possible to do so. Further, these are examples in which the scanning electrode is provided first and the signal electrode and the drain electrode are provided later, but they may be provided in the reverse order.

In the present invention, the picture elements of the same color are driven by the same signal electrode, but in the delta arrangement of picture elements,
If the sampling timing of the analog line memory remains fixed, the reproduced image is shifted by 1.5 pixels to the left and right for each scanning electrode, and the resolution is reduced.
This problem is solved by shifting the sampling timing between the odd line and the even line by a time corresponding to 1.5P (P = effective horizontal scanning time / number of horizontal picture elements). To shift the sampling timing,
This is achieved by delaying the signal driving the signal electrode by 1.5P only in either case depending on whether the selected scan electrode is odd-numbered or even-numbered.

FIG. 4 shows an example of a drive circuit for a liquid crystal display panel according to the present invention. The gate driver 20 formed of a shift register sequentially scans the scan electrodes 11, 11, ... With a horizontal synchronizing signal H, and turns on the transistors 2, 2, ... Connected to the selected scan electrode 11. The time width of the gate pulse does not necessarily have to be 1H (horizontal scanning time), and the pulses applied to the respective scanning electrodes may overlap each other. For making the gate pulse width greater than 1H:
The application has been filed by the present inventors. The purpose is to turn on the scan electrode 11 and precharge the liquid crystal and the storage capacitor prior to the original timing. When used in the embodiment, the video signal of the same color is always applied on the same signal electrode 14, and the signal correlation between adjacent scanning lines is high in a normal video signal, so that the effect of precharging is large. Crosstalk between colors is less likely to occur.

The analog line memory 21 for driving the signal electrodes comprises a shift register 22 and sample and hold circuits 23, 23, .... The shift register 22 generates a sampling pulse by sequentially transferring the start pulse ST with a clock pulse Ck having a period of 1 / 2P. Sample and hold circuit 2
Receiving this sampling pulse, 3, 23, ... Sample the color video signals R, G, B, and drive the signal electrodes 14, 14, ... In synchronization with the gate signal H. In the arrangement of picture elements according to this embodiment, all the picture elements driven by the same signal electrode 14 have the same color.
It is not necessary to switch the color of the video signal input to 3, 23, ....

The start pulse delay circuit 24 shifts the sampling timings of the odd scan lines and the even scan lines. In the example of FIG. 4, when the scan electrodes are even-numbered, the sampling timing is delayed by 3 clock pulses = 1.5P. In such a sampling method, the period = 1 /
A clock pulse of 2P is required, but if it is desired to avoid shortening the clock period, a clock pulse having a period of 1P or 1.5P can be substituted. In the former case, a 1/2 pixel position shift occurs between the odd line and the even line. In the latter case, the G video signal may be sampled at the original timing, and the R and B signals may be simultaneously sampled at the timing corresponding to the central position where both are continuous. Even in this case, the deterioration of the image quality is hardly felt for the following reason. Visual sense has high spatial resolution with respect to brightness (brightness), but spatial resolution with respect to hue is not so high. The contribution to brightness is R,
Since G is the largest of G and B, if G is faithfully reproduced, even if the position shift of 1/2 picture element occurs in R and B, it has almost no visual effect.

Next, although not shown, a common electrode side substrate, in which a transparent conductive film and a color filter are provided on a transparent substrate such as glass, is prepared by a known method. An interference filter, an inorganic or organic dye or pigment is used as the color filter. The color filter is one in which the three primary colors are arranged in delta by photolithography or a printing method so as to correspond to the delta arrangement of the picture element electrodes. On top of this, ITO
The transparent conductive film made of is formed by a method such as ion plating. An alignment layer for aligning the liquid crystal is provided thereon.

A substrate provided with a delta-arrangement pixel electrode and a substrate provided with a common electrode are attached through a spacer,
Liquid crystal is injected into the gap between both substrates to complete a color liquid crystal panel. When the liquid crystal operation mode is TN, polarizing plates are provided on both side surfaces of the liquid crystal panel.

When images were reproduced by the color liquid crystal display panel completed in this way, moire fringes were hard to occur and good resolution and display quality were exhibited.

In the above description, the picture elements that meander the signal electrodes and are driven by the same signal electrode are arranged alternately to the left and right. On the other hand, meanwhile, the picture electrodes meander and the same scanning electrodes alternate vertically. It goes without saying that the same effect will be produced when arranging. In this case, it is necessary to hold a video signal on one or two scanning lines before by a delay element such as a surface acoustic wave (SAW) element or an analog line memory.

FIG. 5 is a diagram showing an embodiment of a color liquid crystal display device to which a non-linear element is added.

In FIG. 5, the pixel electrodes 4 arranged in a delta array.
, 41, ... are respectively non-linear elements 42, 42 ,.
Are connected to the signal electrodes 43, 43 ,. Each signal electrode 43 is meandered so that the amplitude is 1/2 of the picture element pitch, and 1.5 picture element pitch (half cycle) per row.
And the pixel electrodes 41 and 4 of the same color that are alternately arranged on the left and right
1, ... The scanning electrodes 44, 44, ... Are provided in parallel to each other on the opposing substrate in a manner corresponding to the horizontal arrangement of the pixel electrodes 41, 41 ,.

Normally, in the simple matrix method and the non-linear element addition method, the picture elements are driven by the voltage averaging method (see the above-mentioned book). In order to obtain a halftone by the voltage averaging method, the width of the selection pulse applied to the signal electrode is modulated according to the gradation. (See Television Society Journal 31, 940 (1977)). To apply the present invention in this case, for example, FIG.
A pulse width modulation circuit is provided between the sample and hold circuit 23 of the analog line memory 21 and the signal electrode 14. This circuit modulates the width of the selection pulse applied to the signal electrode according to the video signal sampled and held by the sample and hold circuit 23.

In some cases, a digital line memory may be used instead of the analog line memory 21. In this case, the video signal is converted into a digital signal by the AD converter and sequentially stored in the digital line memory. Next, the width of the selection pulse applied to the signal electrode is controlled by the digital video signal stored in the digital line memory. In this case, A
A method is used in which a series of pulses having different pulse widths are generated according to the number of bits of D conversion and a pulse having a pulse width corresponding to the level of a video signal is selected by a multiplexer.

Whether the analog line memory or the digital line memory is used, it is necessary to switch colors in the conventional configuration. However, according to the present invention, as in the case where a switching element is added, the color switching is performed. Switching is unnecessary.

[0049]

According to the color liquid crystal display device of the present invention,
The image resolution is improved and the display quality is good,
The electrode drive circuit can be simplified.

Further, since the length of the signal line can be shortened, the influence of wiring resistance can be remarkably reduced.

[Brief description of drawings]

1A and 1B are diagrams showing an example of a delta array used in the present invention, and FIG. 1C is a diagram showing a relationship between electrodes and a delta array.

2A is a schematic plan view of a TFT, and FIG. 2B is a sectional view taken along line AA of FIG.

3A and 3B are schematic plan views of a TFT.

FIG. 4 is a drive circuit diagram of pixel electrodes in a color array according to an embodiment of a color liquid crystal display device to which a TFT is added.

FIG. 5 is a diagram schematically showing an embodiment in which a non-linear element is added to a simple matrix.

FIG. 6A is a diagram schematically showing a simple matrix display method. FIG. 3B is a diagram schematically showing a double matrix display system. (C) is a figure which shows the case where a non-linear element is added diagrammatically. (D) is a diagram schematically showing a case where a switching element is added.

FIG. 7A is a conventional color array (vertical stripe type).
FIG. FIG. 6B is a diagram showing a conventional color array (horizontal stripe type). (C) is a diagram showing a conventional color array (9-pixel gradation type). (D) is a diagram showing a conventional color array (vertical 6-pixel type). (E) is a diagram showing a conventional color array (horizontal 6-pixel type). (F) is a diagram showing a conventional color array (4-pixel type).

FIGS. 8A and 8B are wiring diagrams when driving liquid crystal by a thin film transistor (TFT) panel having a conventional mosaic pixel array.

[Explanation of symbols]

 1 Thin Film Transistor 2 Capacitor 3 Scanning Electrode 4 Signal Electrode 5 Gate Driver 6 Analog Line Memory 7 Color Switching Circuit 11 Scanning Electrode 12 Gate Insulating Film 13 Semiconductor Film 14 Signal Electrode 15 Drain Electrode 16 Picture Element Electrode 21 Analog Line Memory 22 shift register 23 sample and hold circuit 24 start pulse delay circuit 41 picture element electrode 42 non-linear element 43 signal electrode 44 scanning electrode

Claims (1)

[Claims] 1. A color liquid crystal display device in which picture elements corresponding to red, green and blue colors are periodically arranged linearly, and the picture elements are three lines of red, green and blue in odd lines. The pixels are repeatedly arranged in a fixed order of one cycle, and the even lines are arranged with a shift of 1.5 pixel pitch with respect to the arrangement of the odd lines. The scan electrode or the signal electrode has an amplitude of the above pixel pitch. 1
A color liquid crystal display device, wherein the color liquid crystal display device is formed in a meandering manner such that it has a width of / 2, and is alternately connected to picture elements of the same color on the outside of the meandering convex portion of the same signal line.