JPS63282717A - Active matrix type liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain a high resolution, and also, to prevent the generation of a moire by constituting one picture element of R, G and B, respectively, of two pieces of sub-picture elements of R, G and B, and arranging them repeatedly so that two pieces or more of sub-picture elements of the same color are not continued in the same direction. CONSTITUTION:One picture element is formed by six pieces of sub-picture elements of R1 and R2, G1 and G2, B1 and B2 surrounded by a contour C. Among four quadrants for surrounding an intersection of a scanning electrode in the horizontal direction and a signal electrode in the vertical direction shown in the figure, the sub-picture element for forming one picture element of the same color of R, G or B is assigned to two pieces of quadrants of one pair which face each other across this intersection. To two pieces of quadrants of the other pair, the sub-picture element of the remaining colors is assigned by one color each, respectively. The assignment of these sub-picture elements is executed repeatedly at the intersection of every scanning electrode and a color picture element array is formed. In such a way, a picture element array which has a high resolution and has prevented the generation of a moire can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an active matrix liquid crystal display device, and particularly to a color pixel arrangement thereof.

(Prior Art) Various types of liquid crystal display devices have been developed and put into practical use. Among these, active matrix liquid crystal display devices have attracted particular attention and are being developed because they are capable of displaying extremely fine images. This is a technology in which liquid crystals are arranged in a matrix pattern and these active elements directly drive liquid crystals to display images.

The basic structure of a conventionally known typical active matrix color liquid crystal display device is schematically shown in FIG.
In the figure, 10 is the lower glass substrate, 12 is this substrate 1
A pixel electrode formed on the surface of 0, 14 an active element such as a thin film transistor (TPT), 16 a scanning electrode,
18 is a signal electrode, 20 is a liquid crystal, 22 is a common electrode, 24 is a color filter in which a large number of fine transmission areas of the three primary colors (red), G (green), and B (blue) are arranged, and 26 is a color filter 24. The upper glass substrates 28 and 30 on which are formed are a lower polarizing plate and an upper polarizing plate, respectively. Since each of these constituent elements is conventionally known, a detailed explanation thereof will be omitted, but this device uses white light from below to connect pixel electrodes 12 and common electrodes 2 that are selectively driven by active elements.
2, and passes through the corresponding color transmission area of the color filter 24 to the upper side to display an image. Then, one pixel electrode 1
2 and one color transmission area of the opposing color filter 24 acts to display one pixel,
One picture element is composed of one R pixel, one G pixel, and one B pixel that are in contact with each other. Therefore, each pixel is displayed in a predetermined color by the active element 14 which is selectively activated by signals from the scanning electrode 16 and the signal electrode 18, and color display such as multicolor or full color is performed by additive color mixture of R, G, and 8. It is something that will be realized. In the following description, each RlG and B pixel will be represented by its associated pixel electrode.

By the way, the conventional color pixel array of this color liquid crystal display device can be the same as the color pixel array used in a multiplex type color liquid crystal display device. As such arrays, stripe arrays, mosaic arrays, and triangular arrays are known.

FIG. 7(A) is an example in which a stripe array is used for the color pixel array of an active matrix liquid crystal device, in which sequential scanning electrodes 34% S J+1 , . . . and sequential signal electrodes A , A1+1, ... form one pixel, pixels of the same color are arranged in blocks in the same row direction, and day pixels, G pixels, and B pixels are arranged in blocks in the same column direction. It has a repeating circular arrangement. In the figure, for example, each pixel of RG8 indicated by diagonal lines is combined to form one picture element. Incidentally, below are active elements provided for each pixel.

FIG. 7(B) is an example in which a mosaic arrangement is used for the color pixel arrangement, and the scanning electrodes S J % S J+1 . . .
Among the blocks surrounded by the signal electrode Ai% A t++ . For example, eight pixels of the same color are arranged in each block on the next diagonal line, and G pixels of the same color are arranged in each block on the next diagonal line. An example of a combination of pixels constituting one picture element in this case is shown with diagonal lines.

Further, the triangular array is constructed by shifting the pixels in the above-mentioned mosaic array by half a pitch in each row in the column direction, but a description thereof will be omitted.

(Problems to be solved by the invention) However, in this conventional color pixel array,
Since one pixel is formed at each intersection of the scanning electrode and the signal electrode, there is a problem in that sufficient resolution cannot be obtained.

Roughly speaking, as shown in FIG. 7(B), in the case of a mosaic arrangement, signals inputted from signal electrodes A>, AI+I, . . . are scanned by scanning electrodes SJ, SJ+□, . It is necessary to switch the color information as R, R, G, R, R, G, etc. at each time. This requires an extra drive circuit for switching information, which poses a problem in that the drive circuit becomes complicated.

Roughly speaking, in the case of a stripe array, as shown in FIG. 7(A), color information is transferred to signal electrodes A, AI+1%...
・The driving circuit is not complicated.However, each color of day, G, and B is arranged with only that color from the top to the bottom of the display area in the row direction (vertical direction). Therefore, vertical moire occurs in the stripe direction, and in the case of a mosaic arrangement, diagonal moire occurs in the diagonal direction, that is, the diagonal direction of the image display section, and this hardens the image.
There was a problem that the displayed image was hard to see.

An object of the present invention is to provide an active matrix type liquid crystal display device that does not complicate the drive circuit and has a color pixel array that suppresses the occurrence of vertical moire and diagonal moire as described above and provides an easy-to-see display image. It's about doing.

Another object of the present invention is to provide an active matrix liquid crystal display device with a color pixel array that provides high resolution.

(Means for Solving the Problems) In order to achieve these objectives, the active matrix liquid crystal display device according to the present invention takes the following measures.

First, each of R, G and 8 pixels is formed using two sub-pixels.

Of the four quadrants surrounding the intersection of a certain scanning electrode and a signal electrode, two
Allocate subpixels forming one pixel of the same color R, G, or B to each quadrant, and allocate subpixels of the remaining colors one by one to the other two quadrants, and assign these subpixels sequentially. This is repeated at the intersection of each scanning electrode to form a color pixel array.

In this case, the four quadrants surrounding this intersection are the first quadrant, which is the area above the scanning electrode and to the right of the signal electrode, the second quadrant, which is the area above the scanning electrode and to the left of the signal electrode, and the second quadrant, which is the area below the scanning electrode. Consider the third quadrant, which is the area on the left side of the signal electrode, and the fourth quadrant, which is the area on the right side of the signal electrode, below the scanning electrode. And among these quadrants, the second and fourth
Subpixels forming one pixel of the same color of R, G, or B are assigned to the quadrant, and subpixels of the remaining two colors are assigned to the first and third quadrants, one by one. Or R in the first and third quadrants
, G, or 8 to form one pixel of the same color, and the remaining two subpixels of the remaining two colors are assigned to the second and fourth quadrants.

Roughly speaking, the three sub-pixels of RlG and B arranged sequentially above the scanning electrode, and the sub-pixel of one of the RlG and B arranged sequentially below the scanning electrode combine to form one pixel of R, G, and B. A total of six sub-pixels including the other three sub-pixels formed by each sub-pixel constitute one picture element.

As described above, in the color pixel array according to the present invention, the colors of the sub-pixels forming one pixel allocated to the area surrounding each intersection of each successive scanning electrode and one common signal electrode are R,
The configuration is such that the color G or B is repeated, and the color is sequentially repeated as R, G, and B at each intersection between a certain scanning electrode and a sequential signal electrode.

According to a preferred embodiment of the invention, an active element can be provided separately for two sub-pixels of the same color extending at the intersection of a certain scan electrode and a signal electrode.

In the present invention, the aspect ratio of the sub-pixel is preferably set to an appropriate value according to the design.

(Function) With the color pixel array of the present invention as described above, R
, G, and 8 pixels of the same color are not arranged consecutively in the - direction, so there is no risk of vertical moire or diagonal moire that conventionally occurs, resulting in an image that is easy to see.

Further, according to the present invention, R, G, 8 constituting one picture element
Each pixel is divided into two sub-pixels, and the two sub-pixels of the same color operate in the same manner as one conventional pixel of the same color, so the resolution is higher than in the past.

Therefore, the active matrix liquid crystal display device of the present invention has better image quality than the conventional one.

Further, according to the present invention, the scanning electrode is arranged so as to pass between each of the subpixels constituting one pixel each of RlG and B, and the signal electrode is placed on the left or right side with respect to the subpixel above the scanning electrode. In addition, since the scanning electrode is arranged on the opposite side (ζ position) to the lower sub-pixel than the upper side, a drive circuit corresponding to the drive circuit for the conventional stripe array can be used. , Therefore, the drive circuit is not complicated.

(Embodiment) An embodiment of the structure of an active matrix liquid crystal display device of the present invention will be described below with reference to the drawings.

It should be noted that the drawings referred to in the embodiments described below are merely shown schematically to the extent that the present invention can be understood, and therefore the shapes, dimensions, and arrangement of each component may differ. The 1ff31 section is not limited to the illustrated example.

FIG. 1 is an explanatory diagram of a color pixel arrangement for explaining the active matrix type liquid crystal display device of the present invention, and is shown as a planar view of the image display surface.

In the embodiment shown in FIG. 1, each of the pixels R, G and B is divided into two sub-pixels R4 and R, respectively, according to the invention.
2, Gl and G2, B, and B2. A scanning electrode and a signal electrode are provided between each subpixel electrode corresponding to these subpixels. Two scan electrodes S, , Sj, and V are shown in sequence as representatives of a large number of scan electrodes provided in the row direction. Similarly,
Among the many signal electrodes arranged, representative ones include signal electrodes b1-1 to bi+1 for B pixels, signal electrodes r+ -r1++ for R pixels, and signal electrodes 9 for G pixels. ~9i+
These signal electrodes are collectively referred to as a b signal electrode, an r signal electrode, and a 9 signal electrode, respectively, as required.These r, g, and b signal electrodes are used for each scan as in the conventional case. In addition to being provided orthogonally to the electrodes, a large number of r, 9, and b signal electrodes for each pixel group constituting one picture element are arranged in a column direction in a manner that is repeated periodically.

The arrangement of subpixels obtained by dividing into two as described above will be explained below.

As shown in the figure, the scan electrodes S j and S J+I sequentially arranged in the row direction intersect with the r, 9, and b signal electrodes, sequentially forming a large number of intersections. When the image display surface is viewed two-dimensionally, four regions, ie, four quadrants, defined by the scanning electrodes and the signal electrodes are formed around each intersection. These areas are
As shown in the quadrant explanatory diagram of FIG. 2, a first quadrant Q1 is an area above the scanning electrode S and to the right of the signal electrode A, a second quadrant Q2 is an area above the scanning electrode and to the left of the signal electrode, The third quadrant Q is the area below the scanning electrode and to the left of the signal electrode.
3 and the fourth quadrant Q4, which is a region below the scanning electrode and to the right of the signal electrode.

Therefore, if we focus on the four quadrants around the intersection of the scanning electrode Sj and the signal electrode ri in FIG. R2, one subpixel G of the remaining two colors G and B is assigned to the first quadrant, and the other subpixel B2 is assigned to the third quadrant. Then, active elements T1 and T2'a are connected to the pixel electrodes of subpixels R8 and R2 of the same color among the subpixel electrodes to which subpixels are assigned in this way, so that the pixels on both sides can be controlled and driven as one eight pixels. Connections are made to each.

Around the intersection of the same scanning electrode S and signal electrode 91, sub-pixels G and G2 of 0 pixel are assigned to the second and fourth quadrants, respectively, and
One of the sub-pixels B1 is assigned, and the other sub-pixel R2 is assigned to the third quadrant. and,
Among the subpixel electrodes to which subpixels are assigned in this way, active elements T1 and T2 (reference numerals in the figure ) are connected and formed, respectively.

Similarly, around the intersection of the scanning electrode S and the signal electrode bi, sub-pixels B and B2 of the B pixel are assigned to the second and fourth quadrants, respectively, and the remaining two colors R are assigned to the first quadrant. and G, and the other sub-pixel G2 is assigned to the third quadrant.

Then, active elements TI and T2 ( The numbers in the figure are omitted.) They are connected to each other.

In this way, subpixels are arranged in the same allocation method for the same scanning electrode at each intersection with the r, 9, and b signal electrodes in each subsequent cycle.

Furthermore, in this embodiment, the next scanning electrode SJ++
I @ beginning, each scanning electrode and these signal electrodes ri, 9
At each intersection with i and bl, each subpixel is repeatedly arranged in the same subpixel color arrangement as in the case of the scanning electrode S and each signal electrode ri, 9i, and bI described above.

As can be understood from the above configuration, in the present invention, one of a pair of sub-pixels forming one pixel of the same color for each scanning electrode is placed above each scanning electrode and on the left side of the signal electrode (or One electrode is arranged on the right side), and the other is arranged below the same scanning electrode and on the right side (or left side) of the same signal electrode. Then, the sub-pixels above a certain scanning electrode are sequentially arranged in the column direction...R+, Gl, sl,
They are repeatedly arranged in the order of R1, Gl, sl, R1, +31, al, . . . , and the lower subpixel is shifted to the left or right by one signal electrode, and similarly in the column direction. Day 3
,G4,B7,day 7,G,,8. ,R,,Gl,B
The sub-pixels are arranged repeatedly in the order of +, .

In this way, in this invention, sub-pixels of three colors are allocated to the area surrounding the intersection to form a color pixel array. Combinations of the six sub-pixels making up the image are shown with diagonal lines.

For the color pixel arrangement as described above, each subpixel electrode corresponding to the two subpixels B1 and R2 of day, the two subpixels G1 and G2 of G, and the two subpixels B1 and B2 of B has a pixel of each color. By adding the same color information corresponding to each subpixel, multicolor or full color can be realized by additive color mixing of these six subpixels. in this case,
As a drive circuit for inputting these color information, the same drive circuit as that used in the conventional stripe array can be used.

FIG. 3 is a diagram showing a display pattern for explaining a comparison of the display between the color pixel array according to the present invention configured as described above, and the conventional stripe array and mosaic array. The subject used in this comparative example is the letter "A", and the letter font is t5x7. Roughly speaking, one character displayed by 5x7 picture elements is approximately 4.2 mm in height and 3.2 mm in width. In order to make the sizes almost equal, the vertical pixel pitch and the horizontal pixel pitch are set to 300 μm and 200 μm for one color pixel array of the present invention.
and 380um and 3 for mosaic arrangement.
20 μm, and 600 um and 210 um for striped arrays. Under the above conditions, the letter "A" was displayed in a single color of B.

FIG. 3(A) is a display pattern using a color pixel array according to the present invention, FIG. 3(B) is a display pattern using a mosaic array,
FIG. 3(C) shows a display pattern in a stripe array, and display locations are shown with diagonal lines. As can be understood from this comparative example, the color pixel array of the present invention is easier to see than the mosaic or stripe arrays. Further, in the case of the color pixel array of the present invention, unpleasant moiré such as the vertical moiré seen in stripes and the diagonal moire seen in mosaics was not observed at all. Such comparison results are the same even if the character font and character size are set to other conditions, and the aspect ratio does not need to be limited to the above values, for example, 4:3 or 2:3.
Even if you change it to 1 or some other value, the aspect ratio of the font will change, but it will not affect the appearance of moire etc. at all.

Figure 4 is a schematic diagram for explaining the arrangement of one picture element, one pixel, two sub-pixels, and the active elements that drive them. In the same figure, the scanning electrodes are Sj, SJ+
7. SJ+□, signal electrode rs, 9. , bs and Wi
, r , Wi, t++, Wii, ya, each have one line j, j+
1. This is the pixel in the second column. This one picture element W89.
~W, , +2 are R1. j
, G1. j,Bm,.

~R1, J+2, Gt, t+2, B1. It shows that it includes one each of J+2 pixels, and thus includes a total of six sub-pixels. Roughly speaking, 40 is a liquid crystal, and 42 is an active element. As can be understood from this figure, the scanning electrodes S J , S j++, S
The positions of J+2, etc. and the signal electrodes r1.91, bl, etc. are such that the active element above the scanning electrode and the active element below the scanning electrode are left and right opposite to the signal electrode. The same signal information is written into two sub-pixel electrodes that constitute one pixel of the same color.

FIG. 5 is a diagram schematically showing the arrangement state of one picture element by taking a part of the image display surface. In the figure, horizontal lines indicate scanning electrodes, vertical lines indicate signal electrodes, and picture elements consisting of six sub-pixels: R2, GI and G2, B1 and B2. Each is shown surrounded by a closed curve C.

It should be noted that the arrangement of sub-pixels constituting each pixel illustrated in the above-mentioned embodiments is not limited to the arrangement from the second quadrant to the fourth quadrant in the illustrated example, but from the first quadrant to the fourth quadrant. 3
It may also be an array in the quadrant direction.

(Effects of the Invention) As is clear from the above description, according to the active matrix liquid crystal display device of the present invention, one pixel of each of R, G, and B constituting one picture element is 2
Since the color pixel array is composed of 10 sub-pixels and is arranged in a color pixel array in which two or more sub-pixels of the same color are not consecutively arranged in the same direction, images can be obtained with high resolution, and unlike conventional It is possible to obtain an image that is easy to view without causing any moiré. Therefore, according to this invention,
An active matrix liquid crystal display device with high quality display can be obtained.

Further, according to the active matrix liquid crystal display device of the present invention, the scanning electrode is arranged to pass between each subpixel constituting each pixel, and the signal electrode is arranged to pass between the subpixels above the scanning electrode. Since it is located on the left or right side and is located on the opposite side to the upper side of the sub-pixel on the lower side of the scanning electrode, a drive circuit corresponding to the drive circuit for the conventional stripe array can be used. Therefore, the drive circuit does not become complicated.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the color pixel arrangement of the active matrix type liquid crystal display device of the present invention, FIG. 2 is a quadrant explanatory diagram for explaining FIG. 1, and FIG. A diagram showing a display pattern for explaining a comparison of display with a device, FIG. 4 is a diagram showing the arrangement relationship of one picture element, one pixel, and an active element, and FIG. 5 is a diagram showing the arrangement state of one picture element. , Fig. 6 is a diagram showing a typical basic configuration of active matrix color liquid crystal display production, Fig. 7 (A) and (B)
1 is a diagram for explaining a conventional color pixel arrangement. 10... Lower glass substrate, 12... Pixel electrode 14.
42, T1, T2...active element (switching element) 16, S, SJ, S*+1. SJ+2...Scanning electrode 18, A, rr, r++. % 9t, 9+++, b
1++, b (, b +++...Signal electrode 20.40...Liquid crystal, 22...Common electrode 2
4... Color filter, 26... Upper glass substrate 28... Upper polarizing plate, 30... Lower polarizing plate R
1, j, R1, j +, RL, J and 2, GL, j, G
1. J+l, Gt, *+2, B1. J, St, j+
+, 81, J+2...1 pixel W Natsume-J -W 1- j + I, W l -
J + 2 °°° 1 picture element Q, ... 1st quadrant,
G2...second quadrant Q3...third quadrant,
G4... Fourth quadrant. Patent applicant Oki Electric Industry Co., Ltd.--br-+
ri 9t bt r+++ 914
11 b+++ --- Breast, Sj+I・scanning electrode
T1. T2 Near active element bx-f ~bx+
+, rr, rr+j-91,9+++: Signal electrode R,, R2, G,, G2.8. , B2: Sub-pixel. Explanatory diagram of the color pixel arrangement of the present invention. Figure 2 Display pattern comparison example Figure 3 Arrangement status of C1 picture element 1 picture element Figure 5 Active matrix type color liquid crystal display device Pixel Arrangement Figure 7 Procedural Amendments July 17, 1986

Claims (4)

[Claims] (1) R individually driven by active elements connected to mutually orthogonal scanning electrodes and signal electrodes;
In an active matrix liquid crystal display device that includes G and B pixels and has a large number of picture elements formed by these R, G, and B pixels, each of the R, G, and B pixels is divided into two sub-pixels. One pixel of the same color of R, G, or B is formed in two quadrants of one set facing each other across the intersection among the four quadrants surrounding an intersection between a certain scanning electrode and a signal electrode. the remaining color subpixels are assigned to each of the two quadrants of the other set, and the assignment of these subpixels is repeated at the intersection of each scanning electrode to form a color pixel array; One pixel of R, G, and B is formed by combining three subpixels of one of R, G, and B arranged sequentially above the scanning electrode and one of the subpixels arranged sequentially below the scanning electrode. An active matrix type liquid crystal display device characterized in that one picture element is formed by the other three sub-pixels. (2) The active matrix liquid crystal display device according to claim 1, wherein the two quadrants of the one set are the second and fourth quadrants. (3) The active matrix liquid crystal display device according to claim 1, wherein the two quadrants of the one set are the first and third quadrants. (4) Claims 1 to 3, characterized in that active elements are individually provided for two subpixels of the same color at the intersection of a certain scanning electrode and a signal electrode.
The active matrix liquid crystal display device according to any one of the items.