JPH0640252B2 - Color image display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a high-quality pixel array of a dot matrix type color image display device.

[Conventional technology]

When displaying an image, it is said that it is most natural to arrange the color display dots of the three primary colors of red, green, and blue in a triangular arrangement so as to stack bricks (1985 International).
Display Research Conference (Inter-nati
onal DisplayReser-ch Conference), pages 24-26).

A conventional triangular array diagram of red (R), green (G), and blue (B) color display dots is shown in FIG. Further, FIG. 6 shows a color display dot arrangement and a circuit configuration of a conventional active matrix type color image display device using a liquid crystal and a thin film field effect transistor as a switching element for driving each color display dot. Also, in FIG.
It is an equivalent circuit diagram of one color display dot. Figure 8 shows
It is a figure which shows the structure of 1 pixel at the time of dividing one color display dot into three color display cells.

In FIG. 5, the R, G, and B color display dots 2 are
The cells of the same color are arranged in a triangle so that they are not adjacent to each other. The pixel 3 surrounded by a thick solid line is composed of a set of R, G, and B color display dots. In FIG.
The scanning circuit 4 generates a scanning pulse, which is applied to the gate of the thin film field effect transistor through the gate line 6 in a line sequential manner. The video signal processing circuit 5 processes the video signal to generate a voltage corresponding to the brightness of each display dot, and applies the voltage to the drain of the thin film field effect transistor through the drain line 7. The thin film field effect transistor is formed in a portion indicated by 8. In FIG. 7, 10 is a thin film field effect transistor, and 11 is a liquid crystal capacitor. Further, in order to remedy defects in the color display dots due to defects such as defects in thin film transistors that drive the color display dots, a plurality of color display dots 2 are formed as indicated by the dotted line in the color display dots 2 in FIG. Even if one color display cell is divided into the color display cells 1 and becomes defective, a structure that avoids a complete defect by displaying other normal color display cells may be adopted.

The operation of this display device will be described with reference to FIGS. 6 and 7. First, the video signal processing circuit 5 parallelizes serial video signals in one horizontal scanning period to generate a signal voltage to be input to each color display dot 2 and to generate a signal voltage for each color display dot 2 through the drain line 7. It is applied to the drain of the thin film field effect transistor 10. Next, a scanning pulse is applied to the gate line 6 to be selected by the scanning circuit 4. The thin film field effect transistor 10 of each color display dot 2 connected to the gate line 6 to which the scanning pulse is applied.
Is turned on, the signal voltage applied to the drain is input as a signal charge to the capacitor 11 using the liquid crystal itself of each color display dot 2. When the field effect transistor 10 is turned on for a certain period of time to sufficiently store the signal charge in the liquid crystal capacitor 11, the gate line 6 is deselected and the field effect transistor 11 is turned off.
Since the signal charge is held in the liquid crystal capacitor 11, the liquid crystal can be driven by this voltage. In this way, the video signal processing circuit 5 parallelizes the video signals in one horizontal scanning period and applies the processed signals to the drain line 7, and the gate lines 6 are sequentially applied with selection pulses from the scanning circuit 4 by the line sequential method. The image can be displayed by repeating the process.

[Problems to be Solved by the Invention]

Now, the number of pixels is 1000 in the horizontal direction (3000 in the case of color display dots), 1000 in the vertical direction, the aspect ratio of each pixel is 1: 1, that is, the pixel pitch also has an aspect ratio of 1: 1.
Considering the color image display device of (1), one color display dot has an aspect ratio of 3: 1 (FIG. 5). As can be seen from FIG. 5, one color display dot has a considerably long length, and even if it is arranged in a triangle, the pixel configuration is unnatural. Even when an image is actually displayed, a vertically long display dot is conspicuous and unnatural, especially in the case of an image whose luminance changes in an oblique direction.

It is an object of the present invention to provide a display device having a pixel array in which a natural image in which vertically long display dots are not noticeable can be obtained, particularly in a color image display device having a pixel aspect ratio close to 1: 1.

[Means for Solving the Problems]

According to the present invention, an image in which a color display dot of one color is formed from a plurality of color display cells of the same color, the color display dots of the three colors are arranged in a triangle, and one set of the color display dots arranged in the triangle is defined as one pixel. In the display device, 1 for each color
The plurality of color display cells forming one color display dot are arranged in a triangle.

[Action]

FIG. 1 is an array of color display dots according to the present invention. In FIG. 1, each display dot is composed of three color display cells, and these three color display cells are arranged in a triangle. Therefore, like the color display dots shown by the thin solid lines in FIG. 1, the color display dots of each color are triangular, so that even in the case of an image whose luminance changes in an oblique direction, a vertically long color like a conventional display device is used. It is possible to obtain a high quality and natural image display without conspicuous display dots.

〔Example〕

FIG. 1 is an array diagram of a color display cell according to the present invention. FIG. 2 is a dot arrangement and circuit configuration diagram showing an embodiment of an active matrix type color liquid crystal image display device according to the present invention.

In FIG. 1, R, G, and B surrounded by a dotted line indicate one color display cell 1. One color display dot 2
As shown by the thin solid line, three color display cells 1 of the same color are arranged in a triangle so as to stack bricks.
The color display dots 2 have a shape close to a triangle because the color display cells 1 are arranged in a triangle. The triangular color display dots 2 are arranged alternately in the vertical direction in the horizontal direction to form one pixel 3 from a set of R, G, and B color display dots 2. 1 pixel is 3
It is composed of color display cells 1 for rows.

In FIG. 2, the scanning circuit 4 generates a scanning pulse, which is applied to the gate of the thin film field effect transistor through the gate line 6 in a line sequential manner. The video signal processing circuit 5 processes the video signal to generate a voltage corresponding to the brightness of each display dot, and applies the voltage to the drain of the thin film field effect transistor through the drain line 7. The thin film field effect transistor is formed in a portion indicated by 8. As shown in FIGS. 1 and 2, in the color display dot arrangement of the present invention, three rows of color display cells form one row of pixels, so that by forming the gate line 6 between the color display cells, Two gate lines 6 are arranged in parallel.

The operation of this display device will be described with reference to FIGS. 2 and 7. First, in the video signal processing circuit 2, the serial video signals in one horizontal scanning period are processed in parallel to generate a signal voltage to be input to each color display dot 2, and the signal voltage of each color display dot 2 is supplied through the drain line 7. It is applied to the drain of the thin film field effect transistor 10. As shown in FIG. 2, since the color display dot 2 is composed of three color display cells, one drain line 7 corresponds to the drains of three thin film field effect transistors. Next,
A scanning pulse is applied to the gate line 6 to be selected by the scanning circuit 4. Since the thin film field effect transistors 10 of the color display cells 1 for three rows connected to the gate line 6 to which the scanning pulse is applied are in the ON state, the signal voltage applied to the drain changes the signal voltage applied to each color display cell 1 The signal charge is input to the capacitor 11 using the liquid crystal itself. After the field effect transistor 10 is turned on for a certain period of time to sufficiently accumulate the signal charges in the liquid crystal capacitor 11, the gate line 6
When the field effect transistor 11 is turned off by deselecting, the signal charge is held in the liquid crystal capacitor 11, so that the liquid crystal can be driven by this voltage. In this way, in the video signal processing circuit 5, the video signals in one horizontal scanning period are parallelized and applied to the drain line 7,
An image can be displayed by repeatedly applying a selection pulse from the scanning circuit 4 to the gate line 6 sequentially in a line-sequential manner.

A liquid crystal color image display device having a display area of 240 mm wide and 180 mm long (12 inches diagonal) according to the present invention was manufactured. The number of pixels is 640 horizontal and 48 vertical
0, and the pixel pitch was 375 μm both vertically and horizontally.
The total number of pixels was 307,200, and the total number of color display dots was 921,600 by multiplying the total number of pixels by 3. Therefore, the total number of color display cells is 2754800, and the pitch of color display cells is 1 in both vertical and horizontal directions.
The shape was square at 25 microns. When an image was actually displayed on this display device, not only characters but also a landscape image or the like was displayed, and a natural image display without vertical eyes was obtained. Further, since the color display dot is composed of three color display cells, even if one color display cell is defective, the defect can be remedied by another normal color display cell. Further, as shown in FIG. 2, two gate lines are arranged in one row of pixels, and by connecting the two gate lines on the opposite side of the scanning circuit 4, one gate line is formed. Even if a disconnection occurs, a line defect is prevented by supplying a scanning pulse from another gate line.

Another pixel array diagram according to the present invention is shown in FIG. In this case, six color display cells are arranged in a triangle to form one color display dot close to a triangle, and further three color display dots form one pixel. Also in this embodiment, the same effect as the above-mentioned embodiment can be obtained.

FIG. 4 shows still another pixel array diagram according to the present invention. In this case, four color display cells are arranged in a triangle to form one diamond-shaped color display dot, and further three color display dots form one pixel. Also in this embodiment, a natural display in which the shape of the display dot is not noticeable can be obtained.

The case of an active matrix type using liquid crystal as a display element has been described above, but the present invention similarly uses liquid crystal to arrange color display cells in a triangular arrangement. The present invention can also be applied to a simple matrix type display device and other color image display devices such as an electroluminescent element and a plasma display.

〔The invention's effect〕

As described above, according to the color image display device of the present invention, it is possible to obtain a high-quality and natural display in which the shape of the display dots is not conspicuous particularly in the display of a landscape image, which is practically effective. .

[Brief description of drawings]

FIG. 1 is a color display dot arrangement diagram according to the present invention, FIG. 2 is a color display dot arrangement and circuit configuration diagram showing an embodiment of a color image display device according to the present invention, and FIGS.
FIG. 7 is another color display dot arrangement diagram according to the present invention, FIG. 5 is a conventional color display dot arrangement diagram, FIG. 6 is a color display dot arrangement and circuit configuration diagram of a conventional color image display device, and FIG. An equivalent circuit diagram of one color display dot, and FIG. 8 is a configuration diagram of one pixel. In the figure, 1 ... color display cell, 2 ... color display dot, 3 ... pixel, 4 ... scanning circuit, 5 ... video signal processing circuit, 6 ... gate line, 7 ... drain line, 8 ... …
Thin film field effect transistor forming part, 10 ... Thin film field effect transistor, 11 ... Liquid crystal capacitor.

Claims (1)

[Claims] 1. A color display dot of one color is formed from a plurality of color display cells of the same color, the color display dots of three colors are arranged in a triangle, and one set of the color display dots arranged in the triangle is defined as one pixel. In the image display device, the color image display device is characterized in that the plurality of color display cells forming one color display dot of each color are arranged in a triangle.