JP2001343636A - Matrix type color display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce disturbance in the picture quality observed as vertical or horizontal lines in a matrix type color liquid crystal display device. SOLUTION: A plurality of pixels are arranged in a matrix in the row direction and column direction, and each pixel is divided into sub pixels of R, G, B to make color display possible. The G sub pixel having highest luminance among the sub pixels of the three primary colors R, G, B is arranged in the center of each pixel. The peripheral sub pixels are arranged by alternately exchanging the colors R and B by every column. Because the G sub pixel having highest luminance in the three primary colors is arranged in the center of each pixel while other sub pixels are arranged in the peripheral part of each pixel, and because the relative position of sub pixels arranged in the peripheral part differs by every column, the disturbance in the picture quality observed as vertical lines by proximity observation can be hardly caused while coloring of the display relating to the sub pixels is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type color display device in which a plurality of pixels are arranged in a matrix, and each pixel is formed by using sub-pixels of three primary colors to perform color display.

[0002]

2. Description of the Related Art A matrix type color display device such as a color liquid crystal display device is generally characterized by being thin and lightweight. Therefore, Cathode Ray Tube to CRT
As a display device that replaces a cathode ray tube, which is abbreviated as "CRT", it is widely used for portable devices and the like. For example, Thin
As an active matrix type liquid crystal display device using a thin film transistor, which is abbreviated as a TFT from the Film Transistor, as a switching element, a size of 20 inches or more whose diagonal length reaches 50 cm has been put to practical use. Although the liquid crystal display device is a non-light emitting type display device, the self-luminous type matrix type color display device has a diagonal length of 100 cm.
Plasma displays of at least 40 inches have been put to practical use. In a matrix type color display device, color display is performed by a method of mixing colors spatially or temporally. In particular, in the case of a direct-view type, a method of performing color mixture by using three sub-pixels of the primary colors and performing additive color mixing at each pixel is most widely used.

FIG. 13 shows an example of an array of sub-pixels used in a TFT active matrix type liquid crystal display device. In the currently mainstream liquid crystal display device, each liquid crystal display element controls the amount of light, and a color difference is generated by a color filter. Therefore, in a color liquid crystal display element in which one pixel is composed of sub-pixels of three primary colors, a color filter and a liquid crystal display element are arranged corresponding to the arrangement of the sub-pixels as shown in FIG. There is a need.

FIG. 13A shows a delta arrangement, and FIG.
Is a stripe arrangement, FIG. 13C is a mosaic arrangement, FIG.
3 (d) shows a square arrangement, respectively. Each array is
Each has its advantages and disadvantages, and for a computer display, it is required that the pixel aspect ratio be 1: 1. Therefore, a stripe arrangement as shown in FIG. 13B is widely used. Although the delta arrangement shown in FIG. 13 (a) has conventionally been frequently used for television reception, television receivers are increasingly used for multimedia applications represented by the Internet. As shown in FIG.
Examples using the vertical stripe arrangement shown in (b) are increasing. In the stripe arrangement, R, which is a red sub-pixel, G, which is a green sub-pixel, and B, which is a blue sub-pixel, are arranged in the row direction in which horizontal scanning is performed. In the column direction perpendicular to the row direction, sub-pixels R, G, and B of each color are vertically connected.

FIG. 14 shows a partial configuration of an active matrix type liquid crystal display device using a TFT which is most widely used among various matrix type color display devices.
In an active matrix type liquid crystal display device, it is usually necessary to provide an auxiliary capacitor for each pixel in order to hold signal charges for one frame period and to suppress voltage fluctuation due to anisotropy of liquid crystal. In general, the storage capacitor line connected to the storage capacitor is arranged in parallel with the scanning line for each row. The auxiliary capacitance line is formed of a metal wiring using a metal such as aluminum (Al) or tantalum (Ta) from the viewpoint of reducing the electric resistance value. If a metal wiring is used for the auxiliary capacitance line, no light is transmitted, so that the metal wiring part becomes a light shielding area as shown by hatching.

[0006] A prior art for forming one pixel of a color matrix display device into sub-pixels of three primary colors is disclosed in, for example, JP-A-58-23084. In this prior art, a plurality of portions corresponding to three primary color sub-pixels are provided in one pixel for each of the three primary colors so that the resolution does not decrease even if the size of the pixel increases.

[0007]

Even if the size of the matrix type color display device has been increased recently, the proportion of the area occupied by one pixel increases if the number of pixels used for display does not change. Would. In a matrix type color display device that performs color display by additive color mixture using sub-pixels of three primary colors, there is no problem if the pixel pitch is sufficiently small or if the viewing distance from the viewer to the display device is sufficiently large. However, if these conditions are not satisfied, the sub-pixel structure will be observed by the viewer. In particular, in the case of a vertical stripe structure widely used in an active matrix type liquid crystal display device, a resolution condition such that a pixel pitch is sufficiently small or a viewing distance from a monitor to a display device is sufficiently long is satisfied. If this is not the case, for example, when displaying “white solid” for displaying white as a whole, a vertical line in pixel units will be observed by the observer. This is because the commonly used RG
In the three primary colors B, the luminance ratio of each sub-pixel is approximately G: R: B
= 6: 3: 1, and the luminance ratio between the G sub-pixel and the B sub-pixel becomes extremely large. In addition, since the spatial resolution characteristic with respect to the luminance of human vision is superior to the color difference, the luminance difference between the sub-pixels is easily seen as a vertical line. From the viewpoint of the image quality of the display device, it is desirable that such a phenomenon as a vertical line is hardly observed as much as possible. In recent years, when the size and area of a matrix type color display device have been increasing, the number of pixels to be displayed is determined by the screen format. The problem becomes more pronounced.

In an active matrix type liquid crystal display device using a TFT as shown in FIG. 14, an auxiliary capacitance formed for each sub-pixel is connected to a connection point between the TFT and a liquid crystal electrode.
Because of the Cs-on-common structure connected to the auxiliary capacitance line, there is also a problem that the light-shielded area as shown by hatching in FIG. 14 is easily observed as a horizontal line.

An object of the present invention is to provide a matrix type color display device in which the above-mentioned vertical lines and horizontal lines are hardly observed, and the occurrence of image quality disturbance can be reduced.

[0010]

The present invention provides a matrix in which one pixel is composed of sub-pixels of three primary colors, and a plurality of pixels are arranged in a row direction in which horizontal scanning is performed and a column direction orthogonal to the row. In the type color display device, of the three primary colors, the sub-pixel of the first primary color having the highest luminance component is arranged at the center of each pixel, and the sub-pixels of the second primary color and the third primary color are located at the peripheral portion of each pixel. A matrix-type color display device, wherein the matrix-type color display device is arranged in such a manner that a relative position of a first primary color with respect to a sub-pixel is different for each predetermined row on one side and on another side.

According to the present invention, in the matrix type color display device, one pixel is composed of sub-pixels of three primary colors, and a plurality of pixels are arranged in a row direction in which horizontal scanning is performed and a column direction orthogonal to the row. Is done. At the center of each pixel, a sub-pixel of the first primary color having the highest luminance component among the three primary colors is arranged. Around the periphery of each pixel, sub-pixels of the second primary color and the third primary color have relative positions with respect to the sub-pixels of the first primary color.
They are arranged differently for each row. This makes it possible to suppress the occurrence of image quality disturbance observed as a vertical line when the viewing distance is short, while suppressing the coloring phenomenon at the pixel level.

The present invention also provides a color switching circuit for switching the color signal component of the second primary color and the color signal component of the third primary color every horizontal period and outputting the same, and the color signal of the first primary color. The component is supplied to a signal line for displaying a sub-pixel in a central portion of each pixel, and an output of the color replacement circuit is supplied to a signal line for displaying a sub-pixel on one side of the peripheral portion, and the sub-pixel display on the other side. And a signal line driving circuit for supplying the signal lines to the respective signal lines.

According to the present invention, the color exchange circuit converts the color signal component of the second primary color and the color signal component of the third primary color into one.
The signal line driving circuit supplies the color signal component of the first primary color to the signal line for displaying the sub-pixel in the center of each pixel, and outputs the output replaced by the color replacement circuit in the peripheral portion. It is supplied to signal lines for displaying sub-pixels on one side and the other side, respectively. Even if a color display signal of a normal vertical stripe arrangement which does not correspond to the arrangement of the sub-pixels in which the positions of the second primary color and the third primary color are interchanged is input, the sub-pixels of the second primary color and the third primary color are line Can be replaced with the display. The signal line drive circuit can also use the conventional configuration as it is.

In the present invention, a color display signal of three primary colors is input, and the color signal component of the first primary color is supplied to a signal line for displaying a sub-pixel in the central portion, and the color signal component of the second primary color is supplied. And the color signal component of the third primary color are 1
A signal line drive circuit with a switching function, which is alternately switched every horizontal period and supplies the signal line for displaying a sub-pixel on one side of the peripheral portion and the signal line for displaying a sub-pixel on the other side, respectively. It is characterized by.

According to the present invention, the signal line driving circuit with the replacement function receives the color display signals of the three primary colors and supplies the color signal components of the first primary color to the signal lines for displaying the sub-pixels in the center. The color signal component of the second primary color and the color signal component of the third primary color are alternately replaced every one horizontal period, so that a signal line for displaying a sub-pixel on one side of the peripheral portion and a signal for displaying a sub-pixel on the other side are provided. And supply to the line respectively. Even if a conventional color display signal is input, the second primary color and the third primary color are supplied to the sub-pixel display signal line in the peripheral portion of each pixel while the second primary color and the third primary color are switched for each row by the signal line driving circuit. It is possible to perform signal line driving in which image quality disturbance is less likely to occur without increasing the number of components used.

Further, in the present invention, each of the pixels has a rectangular shape surrounded by sides parallel to the row direction and the column direction, and the sub-pixel has a boundary whose rectangular shape is parallel to the column direction. It is characterized by being formed by being separated by a line.

According to the present invention, each pixel has a rectangular shape surrounded by sides parallel to the row direction and the column direction, respectively.
The sub-pixels are formed by dividing a rectangular shape by a boundary line parallel to the column direction, and thus have a stripe arrangement as a whole.
In the column direction, the sub-pixels of the second primary color and the sub-pixels of the third primary color at the periphery of each pixel are alternately switched, so that it is possible to suppress the occurrence of image quality disturbance that appears as a vertical line.

Further, in the present invention, each pixel is constituted by a liquid crystal display element having color filters of three primary colors.

According to the present invention, in a liquid crystal display device having color filters of three primary colors, it is possible to suppress the occurrence of image quality disturbance that appears as a vertical line.

In the present invention, the liquid crystal display element is of an active matrix type, and an auxiliary capacitance line is provided for each row, and each auxiliary capacitance line is formed of a plurality of capacitance lines at substantially equal intervals in a display portion of each pixel. It is characterized in that it is divided into

According to the present invention, in an active matrix type liquid crystal display device having an auxiliary capacitance line, it is possible to suppress the image quality disturbance that appears as a vertical line and to reduce the image quality disturbance of a horizontal line based on the auxiliary capacitance line. .

Further, according to the present invention, in a matrix type color liquid crystal display device using an active matrix type liquid crystal display element in which auxiliary capacitance lines are arranged for each row, the auxiliary capacitance lines arranged for each row are arranged in a display portion of each pixel. The matrix type color display device is characterized by being divided into a plurality of capacitance lines at substantially equal intervals.

According to the present invention, the matrix type color display device uses an active matrix type liquid crystal display element in which auxiliary capacitance lines are arranged for each row. Since the auxiliary capacitance line arranged for each row is divided into a plurality of approximately equally-spaced capacitance lines at the display portion of each pixel, a single auxiliary capacitance line serves as a light-shielding area and prevents image disturbance that appears as a horizontal line. In this case, it is possible to divide the capacitance line to suppress occurrence of image quality disturbance.

[0024]

FIG. 1 shows an arrangement of sub-pixels of a matrix type color display device according to a first embodiment of the present invention. FIG. 1 shows only a 5 × 5 pixel area for convenience of explanation. For example, V of 10.4 type screen size
In the case of the GA (Video Graphics Array) format, the number of pixels is 640 × 480 pixels. The pixel pitch is 330 μm in both the vertical and horizontal directions. Each pixel is composed of three sub-pixels that emit each of the three primary colors of RGB. The arrangement pitch of the sub-pixels is 330 μm in the vertical direction and 1 in the horizontal direction.
10 μm. As described above, in the three primary colors of RGB,
G has the highest luminance. In the present embodiment, the G sub-pixel having the highest luminance is arranged at the center of each pixel. Remaining R
And the B sub-pixel are arranged on both sides of the G sub-pixel. Further, the relative positions of the R sub-pixel and the B sub-pixel are exchanged for each row. The fill factor (aperture ratio in the case of a color liquid crystal display device) of each sub-pixel is generally about 0.3 to 0.9, and the entire sub-pixel does not necessarily contribute to display. In FIG. 1, the fill factor of each sub-pixel is represented as 1 for convenience of explanation.

Although the above-described arrangement of the sub-pixels differs in the manufacturing method depending on the display system, it is basically a matter of the arrangement of the color filters or the light-emitting elements and can be realized relatively easily. For example, in the case of an active matrix type liquid crystal display device using a TFT, TF
The design of the T substrate is performed in the conventional manner, and the pattern design of the color filter provided on the substrate on the opposite side may be performed in accordance with the arrangement of the sub-pixels shown in FIG. When forming a color filter on a TFT substrate for the purpose of improving the aperture ratio,
Similarly, the pattern design of the color filter may be changed.

With the arrangement of the sub-pixels as shown in FIG. 1, the R and B sub-pixels are evenly arranged on both sides of the G sub-pixel. As compared with the conventional vertical stripe arrangement as shown in FIG. 13B in which only the B sub-pixel is arranged on one side, the change in luminance can be made uniform. Interference factors observed as vertical lines of the unit can be reduced. By arranging the G sub-pixel having the highest luminance at the center, it is possible to suppress the interference between the two adjacent pixels.

In the matrix type color display device of this embodiment, it is necessary for the host which supplies a color image signal for display to exchange the color signal components corresponding to the arrangement of the sub-pixels as shown in FIG. is there. Such replacement of color signal components is conventionally performed by software at the stage of forming an image image separately for each color of RGB, or at the stage of hardware for reading a color image and supplying it to a matrix type color display device. It can also be done.

As is apparent from the above description, the matrix type color display device of the present embodiment is not limited to a transmission type or reflection type non-light emitting type liquid crystal display device, but also to a plasma display or EL (electroluminescence).
The present invention can be applied to a self-luminous display device such as a display. Further, it is needless to say that the present invention can be applied not only to the direct view type but also to a projection type display having a sub-pixel configuration.

FIG. 2 shows a schematic system configuration of a matrix type color display device according to a second embodiment of the present invention. In the present embodiment, a case where the matrix type color display device is an active matrix type liquid crystal panel 1 using TFTs will be described as an example. When the liquid crystal panel 1 is of a transmissive type, a backlight and a backlight power supply are additionally provided. The pixels constituting the liquid crystal panel 1 are arranged in a matrix in the row direction and the column direction, and perform color image display by switching control by the TFTs constituting the active matrix. The signal lines in the column direction of the active matrix are each driven by the signal line driving circuit 2. The scanning lines in the row direction of the active matrix are each driven by the scanning line driving circuit 3. The timing of driving the signal line driving circuit 2 and the scanning line driving circuit 3 is controlled by a timing signal provided from the timing control circuit 4. Timing control circuit 4
Is a horizontal synchronizing signal H provided together with the color display signal.
Various timing signals are generated based on the sync, the vertical synchronization signal Vsync, and the clock signal CLK.

The matrix type color display device of the present embodiment is different from the conventional color display device in that it has a color signal switching circuit 5 for alternately switching input color signal components every horizontal period and supplying the color signal components to the signal line driving circuit 2. That is. In each pixel of the liquid crystal panel 1, sub-pixels are arranged as in the embodiment of FIG. The color signal exchange circuit 5 exchanges the R and B color signal components for each horizontal scan according to the switching control signal SEL given from the timing control circuit 4.
By providing such a color signal exchange circuit 5, desired display can be performed only by inputting the same color display signal as in the related art while using the liquid crystal panel 1 having the arrangement configuration of the sub-pixels in FIG. .

The color display signal inputted from the outside is, for example, a digital signal of 18 bits, and each color of RGB is composed of 6 bits. Therefore, the liquid crystal panel 1
In this case, display of 64 tones for each color is performed. The input 18-bit color display signals (R0 to R5, G0
G5, B0 to B5) are sent to the color signal exchange circuit 5 via the buffer circuit 6. In the color signal interchange circuit 5, the color signal components G0 to G5 having the highest luminance among the input color display signals are sent to the signal line drive circuit 2 as they are. On the other hand, the remaining color signal components R0 to R5 and B0 to B5 are alternately exchanged every horizontal period and sent to the signal line driving circuit 2. A required power supply voltage is supplied from a power supply circuit 7 to each part of the matrix type color display device of the present embodiment. The power supply circuit 7 supplies DC power of different voltages separately for, for example, a logic, a scanning line driving circuit, and a signal line driving circuit.

FIG. 3 shows the color signal exchange circuit 5 shown in FIG.
Here is an example. The color signal interchange circuit 5 can be easily realized using, for example, two multiplexer circuits 11 and 12. The switching control signal SEL is supplied to a selection input S of one multiplexer circuit 11 as it is, and is supplied to a selection input S of the other multiplexer circuit 12 via an inverter circuit 13. Color signal components R0
R5 is connected to the A-side inputs of both multiplexer circuits 11 and 12, respectively. The multiplexer circuit 11
The A-side input or the B-side input is switched and derived from the output Y depending on whether the selection input S is at a high level or a low level. With such a configuration, the switching control signal SE
If L is switched between a high level and a low level every horizontal scanning period, the color signal components output from one multiplexer circuit 11 and the other multiplexer circuit 12 can be switched alternately.

FIG. 4 shows a partial configuration in which the control signal SEL is generated by the timing control circuit 4 of FIG. The timing control circuit 4 generates a timing signal required for display based on the input clock signal and synchronization signal. The timing control circuit 4 of the present embodiment is different from the conventional one in that the switching control signal S supplied to the color signal switching circuit 5 is different.
It has a function of generating an EL. The switching control signal SEL can be easily created using the flip-flop circuit 14. Flip-flop circuit 1
4 is cleared when the vertical synchronization signal Vsync connected via the inverter circuit 15 becomes high level,
The output state is inverted every time the horizontal synchronization signal Hsync rises. For example, a signal for deriving the output Q of the flip-flop circuit 14 through the inverter circuit 16 can be used as the switching control signal SEL.

FIG. 5 shows a comparison between the switching control signal SEL generated by the timing control circuit 4 of FIG. 2 and the timing of the scanning signal generated by the scanning line driving circuit 3. The switching control signal SEL goes high when the vertical synchronizing signal Vsync goes high, and thereafter, the horizontal synchronizing signal Hsy
The output level is inverted every time nc rises. When a predetermined number of horizontal scans are completed from the vertical synchronization signal Vsync, the scan outputs SL1, SL2, and SL3 are sequentially output from the scan line drive circuit 3.

The liquid crystal panel 1 has the same structure as the conventional one, except that the color filter arrangement is as shown in FIG. Basically, it has a structure in which a liquid crystal layer is sandwiched between two glass substrates, and a pixel array is formed on one of the glass substrates. One pixel is composed of three sub-pixels, and each sub-pixel is driven by the signal line driving circuit 2 and the scanning line driving circuit 3.

FIG. 6 shows the pixel array section, the signal line driving circuit 2 and the scanning line driving circuit 3 of the liquid crystal panel 1 of FIG. 2 in more detail. The liquid crystal panel 1 is formed so that a large number of scanning lines and a large number of signal lines intersect with each other.
Sub-pixels are arranged in a matrix at a portion surrounded by two scanning lines and two adjacent signal lines.

FIG. 7 shows the structure of one sub-pixel shown in FIG. Each sub-pixel includes a TFT 17 as a switching element, a liquid crystal capacitor CL, and an auxiliary capacitor CS. The auxiliary capacitance CS is the anisotropy of the liquid crystal dielectric constant forming the liquid crystal capacitance CL, the leakage current of the TFT 17,
It is used to suppress the influence of the fluctuation of the sub-pixel potential caused by the parasitic capacitance between the gate and the source of the FT. The signal line DLj is connected to one electrode of each of the liquid crystal capacitance CL and the auxiliary capacitance CS via the source and the drain of the TFT 17 serving as a switching element. The gate of the TFT 17 of the sub-pixel is connected to the scanning line SLi.
The other electrode of the liquid crystal capacitor CL is provided as a counter electrode on the counter substrate side sandwiching the liquid crystal cell. The other electrode of the auxiliary capacitance CS is connected to an auxiliary capacitance line common to all pixels. As shown in FIG. 14, the auxiliary capacitance lines are generally wired in parallel with the scanning lines for each row. Note that i and j are integers in the range of 1 ≦ i ≦ m and 1 ≦ j ≦ n. In the VGA format, m = 480 and n = 640 × 3.

The scanning line DLj is connected to the scanning line driving circuit 3, and the signal line SLi is connected to the signal line driving circuit 2. The scanning line driving circuit 3 sequentially scans the scanning lines DLj and applies a voltage of about 20 to 30 V to the gate of the TFT 17 connected to each scanning line DLj for a necessary period as shown in FIG. have. The signal line driving circuit 2 sequentially samples and holds the input color display signal over one horizontal period, further performs digital / analog (hereinafter abbreviated as “D / A”) conversion, and performs necessary conversion. The signal is output as an analog signal to the signal line DLj at the timing. The scanning line SL by the scanning line driving circuit 3
When i becomes active, the TFT 17 whose gate is connected to the scanning line DLi becomes conductive and the signal line D
The signal output to Lj charges the liquid crystal capacitor CL and the auxiliary capacitor CS via the source and drain of the TFT 17,
The signal output on the signal line is written to the sub-pixel. The charge written to the sub-pixel is held for one frame period,
The display is maintained. A general liquid crystal driver LSI can be used for the scanning line driving circuit 3 and the signal line driving circuit 2.

Since the liquid crystal element is deteriorated by an electrochemical reaction when a DC voltage is applied, it is necessary to perform an AC drive for periodically inverting the polarity of the applied voltage in order to extend the life. Hereinafter, this AC driving is referred to as inversion driving. When the liquid crystal panel 1 using a TFT is driven to be inverted, if the polarity is inverted every frame, the anisotropy of the liquid crystal dielectric constant, the variation of the leak current of the TFT, and the variation of the sub-pixel potential due to the parasitic capacitance of the TFT Due to various factors such as deviation from the center value of the counter electrode signal, it is inevitable that some imbalance occurs between the positive and negative voltages applied to the liquid crystal, and a slight luminance variation occurs at half the frame frequency. Then, it is visually recognized as flicker. As a countermeasure, in addition to reversing every frame,
An inversion driving method is used in which the polarity between adjacent lines or between adjacent pixels is reversed.

As described above, in the matrix type color display device of the present embodiment, only the same color display signal as in the prior art is input, and as in the case of the first embodiment, conventionally, as a vertical line in pixel units, Observed interference factors can be reduced. In the present embodiment, the case of an active matrix type liquid crystal display device is described as an example. However, as in the case of the first embodiment, the present invention is widely applied to display devices of other types. Of course you can.

FIG. 8 shows a schematic system configuration of a matrix type color display device according to a third embodiment of the present invention. In this embodiment, parts corresponding to those in the embodiment shown in FIG. 2 are denoted by the same reference numerals, and redundant description will be omitted.
This embodiment is different from the embodiment of FIG. 2 in that the color signal exchange circuit 5 is not provided as shown in FIG.
Using the signal line drive circuit 22 with the replacement function, the two color signal components whose luminance components are not the highest among the color display signals to be input in the signal line drive circuit 22 with the replacement function are
It is provided with a drive signal switching function of alternately switching every one horizontal period and supplying a driving signal to a signal line for displaying a sub-pixel in a peripheral portion of each pixel. However, since the replacement timing is different from that of the embodiment of FIG. 2, the timing control circuit 24 that generates the control signal SEL is different from the timing control circuit 4 of FIG.

FIG. 9 shows an example of the configuration of the signal line drive circuit 22 with a replacement function used in the matrix type color display device of this embodiment. The signal line drive circuit 22 with the replacement function includes a shift register 31, a data register 32, a latch 33, and a D / A
It includes a converter 34, a drive signal switching circuit 35, an output buffer 36, and a reference voltage generation circuit 37. The configuration excluding the drive signal switching circuit 35 is the same as that of a conventional signal line drive circuit. The drive signal switching circuit 35 is provided before the output buffer 36 that finally drives the signal line, and selects one of the R and B color signal components from the two signals in accordance with the switching control signal SEL. Output to the signal line.

FIG. 10 shows the drive signal switching circuit 3 shown in FIG.
5 shows a configuration corresponding to one pixel. The drive signal switching circuit 35 includes four analog switches 35a, 35b, 35
It can be easily realized using c and 35d. D /
Of the analog signals corresponding to the luminances of the RGB colors respectively derived from the A converter 34 as Rout, Gout, and Bout, the G signal having the highest luminance is directly supplied to the output buffer 36, and the R and B signals are converted into analog signals. Switches are alternately switched by switches 35a, 35b, 35c, and 35d. Switching timing is performed based on a switching control signal SEL supplied from the timing control circuit 24, and is switched every horizontal period. It should be noted here that the timing for switching the signal for display is the timing shown in FIG.
Is delayed by one horizontal period as compared with the embodiment shown in FIG.

Also in this embodiment, just by inputting a color display signal similar to the conventional one, display similar to that of the embodiment of FIG. 2 for mitigating a disturbance factor conventionally observed as a vertical line in pixel units is performed. It can be carried out. Further, in the present embodiment, the case of an active matrix type liquid crystal display device is described as an example, but the present invention can be widely applied to other types of display devices as in the case of the embodiment of FIG.

FIG. 11 shows a schematic pixel configuration of a matrix type color display device using an active matrix type liquid crystal display element 40 according to a fourth embodiment of the present invention.
In the present embodiment, although the TFT 41 is formed on a glass substrate in the same process as in the related art, the auxiliary capacitance lines 42 and 43 are designed with a completely different idea. That is, as shown in FIG. 11, the auxiliary capacitance lines 42 and 43 are divided into two capacitance lines at substantially equal intervals in the picture element electrode 44, which is a portion contributing to the display of each pixel, and are wired. Is done. The sum of the capacitance values of the two auxiliary capacitance lines 42 and 43 in each sub-pixel is set to be the same as the capacitance value of the auxiliary capacitance as in the conventional design. Therefore, the line width of each of the auxiliary capacitance lines 42 and 43 can be made narrower than in the case where the storage capacitance lines 42 and 43 are formed by one conventional auxiliary capacitance line. Further, since there is a space between the auxiliary capacitance lines 42 and 43, even if the auxiliary capacitance lines 42 and 43 are formed of metal wiring and serve as a light-shielding region, they can be made inconspicuous as horizontal lines.

FIG. 12 shows a schematic pixel configuration of a matrix type color display device using an active matrix type liquid crystal display element 50 as a fifth embodiment of the present invention.
In the present embodiment, portions corresponding to the configuration shown in FIG. 11 are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, two auxiliary capacitance lines 42 and 4 are provided in the same sub-pixel.
3 are connected to each other by a short-circuit line 51. An auxiliary capacitance is also formed at the portion where the two auxiliary capacitance lines 42 and 43 are connected by the short-circuit line 51, and a change in potential between the auxiliary capacitance lines 42 and 43 can be reduced.

As described above, the auxiliary capacitance line 4 serving as a light shielding area
By dividing the storage capacitor lines 2 and 43 into two in the display section of each sub-pixel, the line widths of the individual auxiliary capacitance lines 42 and 43 can be reduced and the wirings are wired at substantially equal intervals. In comparison, horizontal lines formed by the auxiliary capacitance lines 42 and 43 can be made inconspicuous. Although FIG. 11 and FIG. 12 illustrate the case of dividing into two, as long as the process does not cause a problem, the dividing into three or more may be performed at all, and the horizontal line can be made inconspicuous. The effect is even more pronounced.

It is of course possible to apply the concept of the fourth or fifth embodiment in combination with the first to third embodiments. The combination makes it difficult to see both vertical and horizontal lines, thereby improving the quality of a color image.

[0049]

As described above, according to the present invention, the positions of the sub-pixels of the second primary color and the third primary color excluding the first primary color having the highest luminance among the three primary color components in each pixel are determined. By replacing each row, it is possible to make it difficult to observe a vertical line for each pixel which is likely to hinder image quality. Therefore, it is possible to improve the image quality especially at the time of white solid display.

Further, according to the present invention, a conventional color display signal is input by using a color replacement circuit for replacing and outputting the color signal components of the second primary color and the third primary color every horizontal cycle. By using the signal line driving circuit as it is, it is possible to reduce image quality disturbance that appears as a vertical line.

Further, according to the present invention, a signal line driving circuit having a switching function, which alternately outputs a color signal component of the second primary color and a color signal component of the third primary color alternately every one horizontal cycle, is used. Even if a color display signal is input as it is, it is possible to reduce the occurrence of image quality disturbance that appears as a vertical line.

Further, according to the present invention, even if the rectangular sub-pixels are arranged in a stripe pattern, the positions of the second primary color sub-pixels and the third primary color sub-pixels at the periphery of each pixel are determined for each row. Since the replacement is performed, it is possible to suppress the image quality disturbance that appears as a vertical line even when approaching, while suppressing the coloring phenomenon at the pixel level.

Further, according to the present invention, in a liquid crystal display device having three primary color filters, it is possible to suppress color phenomena at a pixel level and to prevent image quality disturbance that appears as a vertical line even when approaching. Can be.

Further, according to the present invention, in an active matrix type liquid crystal display device, the arrangement of sub-pixels is changed for each row to suppress the occurrence of image quality disturbance that appears as a vertical line, and the image quality of a horizontal line based on an auxiliary capacitance line is reduced. The occurrence of interference can also be suppressed.

Further, according to the present invention, the auxiliary capacitance line arranged in the row direction is divided into a plurality of capacitance lines at substantially equal intervals in the display portion of each pixel.
It is possible to reduce the occurrence of image quality disturbance that appears as a horizontal line.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement of sub-pixels according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic electrical configuration as a second embodiment of the present invention.

FIG. 3 is a block diagram showing an electrical configuration of a color signal exchange circuit 5 of FIG. 2;

FIG. 4 is a block diagram showing a partial electrical configuration of a timing control circuit 4 of FIG. 2;

5 is a time chart showing a control signal from a timing control circuit 4 and a scanning signal from a scanning line driving circuit 3 in FIG.

FIG. 6 is a partial block diagram showing a configuration for driving a sub-pixel in the liquid crystal panel 1 of FIG. 2 by a signal line driving circuit 2 and a scanning line driving circuit 3.

7 is an electric circuit diagram showing a simplified equivalent electric configuration of the sub-pixel in FIG. 6;

FIG. 8 is a block diagram showing a schematic electrical configuration of a matrix type color display device according to a third embodiment of the present invention.

9 is a block diagram showing an internal configuration of a signal line driving circuit with a replacement function 22 shown in FIG. 8;

FIG. 10 is a block diagram showing an internal configuration of a drive signal switching circuit 35 of FIG. 9;

FIG. 11 is a view schematically showing a part of an active matrix type liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 12 is a diagram schematically showing a part of an active matrix liquid crystal display element 50 according to a fifth embodiment of the present invention.

FIG. 13 is a diagram showing an example of an array of sub-pixels conventionally used in a matrix type color display device.

FIG. 14 is a diagram showing a partial configuration of a conventional active matrix liquid crystal display device using a TFT.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid crystal panel 2 signal line driving circuit 3 scanning line driving circuit 4, 24 timing control circuit 5 color signal switching circuit 11, 12 multiplexer circuit 14 flip-flop circuit 17, 41 TFT 22 signal line driving circuit with switching function 35 drive signal switching circuit 35a, 35b, 35c, 35d Analog switch 36 Output buffer 40, 50 Active matrix liquid crystal display element 42, 43 Auxiliary capacitance line 44 Pixel electrode 51 Short-circuit line

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Claims (7)

[Claims] 1. One pixel is composed of three primary color sub-pixels,
In a matrix type color display device in which a plurality of pixels are arranged in a row direction in which horizontal scanning is performed and in a column direction orthogonal to the rows, a sub-pixel of a first primary color having the highest luminance component among the three primary colors is each pixel. And the sub-pixels of the second primary color and the third primary color are respectively disposed in the peripheral portion of each pixel, and the relative position with respect to the sub-pixel of the first primary color is located on one side and the other side which are predetermined. And a matrix type color display device characterized by being different for each row. 2. A color exchange circuit for exchanging the color signal component of the second primary color and the color signal component of the third primary color every one horizontal period and outputting the color signal component. The signal is supplied to a sub-pixel display signal line at the center of each pixel, and the output of the color replacement circuit is supplied to one of the peripheral sub-pixel display signal lines and the other sub-pixel display signal. 2. A matrix type color display device according to claim 1, further comprising a signal line driving circuit for supplying each of said lines. 3. A color display signal of three primary colors is inputted, and a color signal component of the first primary color is supplied to a signal line for displaying a sub-pixel in the central part, and a color signal component of the second primary color and the color signal component of the second primary color are supplied. The color signal components of the three primary colors are alternately exchanged every horizontal period and supplied to one of the peripheral sub-pixel display signal lines and the other of the sub-pixel display signal lines. 2. The matrix type color display device according to claim 1, further comprising a signal line drive circuit with a replacement function. 4. Each of the pixels has a rectangular shape surrounded by sides parallel to the row direction and the column direction, and the sub-pixel has a boundary line whose rectangular shape is parallel to the column direction. 4. The method according to claim 1, wherein the first and second parts are divided.
A matrix type color display device according to any one of the above. 5. The matrix type color display device according to claim 1, wherein each of said pixels is constituted by a liquid crystal display element having color filters of three primary colors. 6. The liquid crystal display element is of an active matrix type, and an auxiliary capacitance line is provided for each row, and each auxiliary capacitance line is divided into a plurality of approximately equally spaced capacitance lines in a display portion of each of the pixels. 6. The method according to claim 5, wherein
A matrix type color display device as described in the above. 7. In a matrix type color liquid crystal display device using an active matrix type liquid crystal display element in which auxiliary capacitance lines are arranged for each row, the auxiliary capacitance lines arranged for each row are substantially equal in a display portion of each pixel. A matrix-type color display device which is divided into a plurality of spaced capacitance lines.