JPH0451005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a configuration of color pixels in a color liquid crystal matrix panel in which each pixel is independently driven by a switching element.

(Prior art and its problems) Groove-type flat display devices with a large display capacity for displaying graphics, characters, or television moving images are being actively developed. Among such groove-type display devices, color liquid crystal matrix panels are one that has recently been viewed as promising, and their large display capacity and colorization are achieved by layering switching elements on each color pixel to control each color pixel. This is achieved using an independently driven system. As the switching element, a thin film transistor made of polycrystalline silicon, amorphous silicon, or the like is used.

FIG. 6 schematically shows a part of the thin film transistor substrate of a conventional color liquid crystal matrix panel of the switching element stacking method. 1 is a scanning line, 2 is a signal line, 3 is a thin film transistor as a switching element, and 4 is a transparent pixel electrode.

There is a color filter substrate as shown in FIG. 7 so as to cover the whole thin film transistor substrate in parallel, and each color filter 5 of R (red), G (green), and B (blue) They are arranged in precise alignment with the pixel electrodes 4. Although not shown in this figure, a common transparent electrode 6 is provided to cover the entire color filter substrate.
is formed.

A liquid crystal is filled in the gap between the thin film transistor substrate and the color filter substrate, and the liquid crystal of each pixel electrode 4 is driven by the potential difference between the electrodes. FIG. 8 shows an equivalent circuit of one color pixel. In this figure, the same numbers indicate the same parts as in FIGS. 6 and 7. 6 is a common transparent electrode, and 7 is a liquid crystal layer. A signal voltage is generated in each pixel electrode 4 to turn on and off the liquid crystal by switching thin film transistors.

Since the switching speed of thin film transistors is usually not very fast, liquid crystal matrix panels are driven by line-sequential scanning. To explain with reference to FIG. 6, when a gate voltage is applied to one scanning line and all the thin film transistors for one row are turned on, an image signal voltage is applied to each signal line 2, and these image signals Each liquid crystal cell turns on and off according to the voltage. When image signal application for one line is completed, the next scanning line is driven in the same way. Since the liquid crystal has a very large resistance, the applied image signal is accumulated in each liquid crystal cell for one frame time with almost no attenuation, resulting in a clear image display almost similar to static drive.

In this way, conventional liquid crystal matrix panels use line-sequential scanning drive for each row, so in a color liquid crystal matrix panel that uses R-G-B three-color pixels as one full-color pixel, R-G-B three-color The pixels are arranged in parallel in one row as shown in the shaded area in FIG. (Nikkei Electronics, 1984,
9, No. 10, p215). The reason why the color pixels are arranged one by one in each line is to improve the mixing of colors and improve the image quality.

However, problems with such a color liquid crystal matrix panel using one row of parallel arrangement of R-G-B three-color pixels are that a color moiré pattern occurs and that it is difficult to improve the resolution. That is, since color pixels of the same color are continuous in each row, a diagonal color moiré pattern occurs. Furthermore, within the same row, pixels of the same color are separated by two pixels, so the resolution is poor.

(Objective of the Invention) An object of the present invention is to eliminate the above-mentioned drawbacks and provide a switching element lamination type color liquid crystal matrix pattern which does not generate a color moiré pattern, has good resolution, and has high image quality.

(Structure of the Invention) According to the present invention, in a color liquid crystal matrix panel in which R-G-B three-color pixels independently driven by switching elements are arranged in a matrix, the R-G-B pixels arranged in a matrix are arranged. The G-B tricolor color pixels are arranged in two rows of triangles, and the two rows of triangles consist of upright triangles and inverted triangles, and within the two rows, the upright triangles and inverted triangles are arranged alternately. A color liquid crystal matrix panel is obtained in which the switching elements for driving each pixel are connected to the same scanning line in the two rows.

Conventionally, each pixel was driven by line-sequential scanning for each row, whereas the present invention is characterized in that each pixel is driven in two rows at the same time.

In this way, since two rows are driven simultaneously, R-G-
The arrangement of the B three-color pixels can be configured in a triangular shape. If you make it an R-G-B triangular pixel array,
Color pixels of the same color are shifted by 1.5 pixels in the next row, which prevents color moiré patterns from occurring. Furthermore, within the same row, pixels of the same color are separated by only 1.5 pixels, improving resolution.

In order to drive two rows simultaneously as described above, the signal line must be wired to pass through the center of each pixel. If you wire the signal line like this,
The signal line is straight without any complicated bends, and the occurrence of pixel defects due to wire breakage is suppressed. However, each pixel is divided into two by a signal line, and there are two methods: either divide the switching element of each pixel into two accordingly, or connect the divided pixels with wiring without dividing the switching element into two. There is. Of course, even when the switching element is divided into two, it is a feature of the present invention that the two divided pixels are connected by wiring. By doing so, pixel defects due to switching element defects can be reduced.

Examples will be described in detail below with reference to the drawings.

Example 1 FIG. 1 schematically shows a part of a thin film transistor substrate for explaining an example of the first invention of the present application. 1 is the scanning line, 2a, 2b, 2c
are signal lines, 3a, 3a', 3b, 3b', 3c, 3
c' is a thin film transistor for switching, 4a, 4
a', 4b, 4b', 4c, and 4c' are transparent pixel electrodes. Compared to the conventional example shown in Fig. 6, thin film transistors made above and below one scanning line are connected to the scanning line, and thin film transistors made by symmetrically dividing one signal line to the left and right. is connected to the signal line, and the two divided thin film transistors are connected to two transparent pixel electrodes which are also divided by the signal line. One pixel is constituted by the two divided transparent pixel electrodes.

A color filter substrate as shown in FIG. 2 is provided parallel to and covering the entire thin film transistor substrate. The R (red), G (green), and B (blue) color filters 5a, 5b, and 5c are arranged in a triangular shape in precise alignment with each of the two divided transparent pixel electrodes of the thin film transistor substrate. One color filter covers two divided transparent pixel electrodes. A triangular array of R-G-B color filters as shown by the hatched area constitutes one full-color pixel, and an upright triangular array and an inverted triangular array are arranged alternately to constitute a row screen for one scanning line. However, the entire screen of the color liquid crystal matrix is composed of several hundred or more rows of screens.

FIG. 3 shows an equivalent circuit of one color pixel in this embodiment. In this figure, the same numbers indicate the same parts as in FIGS. 1 and 2. 6 is a common transparent electrode, and 7 is a liquid crystal layer. The divided transparent pixel electrodes are connected to each other by pixel electrode connection wiring 8. Therefore, even if one of the divided thin film transistors becomes malfunctioning, both of the two divided pixels are driven by the other thin film transistor, thereby making it possible to compensate for the pixel defect.

In this example, the pitch size of one color filter was 100 μm in length and 120 μm in width. Two two-part pixel electrodes each having a size of 80 μm×100 μm correspond to one color filter. As shown in Figure 1, one full-color pixel consisting of a mixture of three colors is composed of 100μm x 120μm x 3 triangular pairs.
The area will be 36000μm ² . At this time, the pitch between adjacent color filters of the same color is 180 μm.
On the other hand, a single conventional full-color pixel with the same display area of 36,000 μm ² is lined up three times in parallel, as shown in Figure 7, so the pitch between adjacent color filters of the same color is 360 μm, making it horizontally long. mosquito,
Alternatively, in order to keep the display area the same and make the aspect ratio of one full-color pixel close to 1, the pitch size of one color filter must be extremely long (190 μm x 63 μm), making it difficult to improve resolution. Or the colors were mixed insufficiently.

Even when compared with the conventional example using one full-color pixel with the same display area, in this example, one color filter is not elongated, and therefore the thin film transistor substrate and color filter substrate is also easy to create.

Embodiment 2 FIG. 4 schematically shows a part of a thin film transistor substrate for explaining another embodiment of the second invention of the present application. 1 is the scanning line, 2a, 2b, 2
c is a signal line, 3a, 3b, 3c are thin film transistors for switching, 4a, 4a', 4b, 4b', 4
c and 4c' are transparent pixel electrodes. As in the first embodiment, thin film transistors formed above and below one scanning line are connected to the scanning line. Further, the transparent pixel electrode is divided into left and right halves by one signal line, and one pixel is constituted by the two divided transparent pixel electrodes. The difference from Example 1 is that the thin film transistor is not divided into two parts. A feature of the second embodiment is that a thin film transistor is formed only on one side of the divided transparent pixel electrode. Therefore, the number of thin film transistors is reduced to 1/2 compared to Example 1, making manufacturing easier, reducing the number of defects in thin film transistors, and reducing pixel defects.

The color filter substrate used in the second embodiment is exactly the same as that in the first embodiment shown in FIG. R
- High image quality is achieved with the triangular arrangement of G-B color filters.

FIG. 5 shows an equivalent circuit of one color pixel in the second embodiment. One thin film transistor,
The divided transparent pixel electrode is connected to the pixel electrode connection wiring 8
are interconnected by. This pixel electrode connection wiring usually uses metal wiring, but transparent electrodes themselves may also be used. In this case, the manufacturing process is further simplified.

(Effects of the Invention) As explained in detail above, in the color liquid crystal matrix panel according to the present invention, the three color pixels of R, G, and B constituting one full color pixel are arranged in a two-row triangular arrangement. A display panel with good resolution and excellent color mixing properties can be obtained. Furthermore, in order to create a two-row triangular array, the transparent pixel electrode for one pixel is divided into two by a scanning line, but by connecting these two divided transparent pixel electrodes with mutual wiring, the Defects can be significantly reduced.

Although thin film transistors were used as switching elements in the above embodiments, it is clear that similar effects can be obtained by using other nonlinear switching elements such as thin film diodes MIM.

[Brief explanation of the drawing]

FIG. 1 is for explaining one embodiment of the present invention.
A schematic diagram showing the planar structure of a thin film transistor substrate,
Fig. 2 is a planar filter arrangement diagram of a color filter board showing the arrangement of R-G-B three-color color filters, Fig. 3 is an equivalent circuit diagram of one color pixel, and Fig. 4 is another example of the present invention. FIG. 5 is a schematic diagram showing a planar structure of a thin film transistor substrate for explaining an embodiment, and FIG. 5 is an equivalent circuit diagram of one color pixel. FIG. 6 is a schematic diagram showing the planar structure of a conventional thin film transistor substrate, FIG. 7 is a planar filter arrangement diagram of a color filter substrate, and FIG. 8 is an equivalent circuit diagram of one color pixel. 1... Scanning line, 2, 2a, 2b, 2, c... Signal line, 3, 3a, 3a', 3b, 3b', 3c, 3
c'...Thin film transistor, 4, 4a, 4a', 4
b, 4b', 4c, 4c'...transparent pixel electrode, 5,5
a, 5b, 5c...color filter, 6...common transparent electrode, 7...liquid crystal layer, 8...pixel electrode connection wiring.

Claims (1)

[Claims] 1. A color liquid crystal matrix in which R-G-B three-color pixels are arranged in rows and columns and are driven independently by switching elements connected to scanning lines and signal lines arranged in a matrix. In the panel, the R-G-B three-color pixels arranged in a matrix form are arranged in a two-row triangle, and the two-row triangle consists of an upright triangle and an inverted triangle, and within the two rows, the upright triangle and The inverted triangles are arranged alternately, and the switching elements that drive each pixel in the two rows are connected to the same scanning line in the two rows, and the switching elements that drive each pixel in the two rows are connected to the same scanning line in the two rows to drive each color pixel of the three colors R, G, and B. The switching element to be driven is divided into two by a signal line, and the two divided switching elements are connected to each divided pixel of the divided color pixel and the divided signal line. A color liquid crystal matrix panel characterized in that divided color pixels are interconnected by wiring. 2. In a color liquid crystal matrix panel in which R-G-B three-color pixels are arranged in a matrix and are driven independently by switching elements connected to scanning lines and signal lines arranged in a matrix, The R-G-B three-color pixels arranged in are arranged in two rows of triangles, and the two rows of triangles consist of upright triangles and inverted triangles, and the upright triangles and inverted triangles are arranged alternately within the two rows. The switching elements that drive each pixel in the two rows are connected to the same scanning line in the two rows, and each color pixel of three colors R, G, and B is divided into two by a signal line, There is only one switching element that drives the two-divided color pixel, and it is connected to one of the two divided color pixels and the two-divided signal line, and the two-divided color pixel is connected to the two-divided color pixel by wiring. A color liquid crystal matrix panel characterized in that the panels are interconnected.