JPH0933886A - Driving method for light source color switching type color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source color switch system color liquid crystal display device without necessitating a color filter and advantageous for resolution and a light transmittance. SOLUTION: This method is the drive method for the light source color switching type color liquid crystal display device successively selectively light emitting light source colors different from each other among three colors R, G, B arranged on display areas adjacent to each other of the display areas (A-E) dividing a display pixel part corresponding to respective display areas. Thus, since display (color) signals are time division displayed in respective display areas in the direction of a time base, and the color signals are time division displayed in the direction of a vertical scan (that is, at every display area) also, the high resolution is obtained even when a moving image is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a color liquid crystal display device of a light source color switching type which does not require a color filter.

[0002]

2. Description of the Related Art In a conventional color display device, R, G and B color filters as shown in FIG. 6 are provided on a two-dimensionally arranged liquid crystal pixel, and color display is performed by turning on a white light source. Was there.

This color filter type liquid crystal panel is
Since each pixel of RGB color is arranged at a different position in the panel, the resolution is about 1/3 and the light transmittance is 1/3 or less as compared with the black and white liquid crystal panel without a filter. .

As a method of solving the problem of the color filter as described above, a method of sequentially inputting signals of R, G and B colors to a black and white liquid crystal panel and switching display of light source colors corresponding to the color signals. (Patent Publication No. 63-41078, etc.).

FIG. 7 shows an explanatory view in the case of the light source color switching system in which the light source colors are switched over the entire panel surface. In the light source color switching frame sequential method, writing and display of three color signals are individually performed within one vertical scanning period. for that reason,
The writing period did not contribute to the display and the display efficiency was low.

Therefore, a proposal for improving the display efficiency is disclosed in Japanese Patent Laid-Open No. 5-80716. This is to lengthen the lighting time by dividing the inside of the panel into a plurality of display areas and controlling the lighting of the light source color for each display area. An example of this light source color switching block sequential system will be described with reference to FIG.

In the example shown in FIG. 8, the display surface of the panel is divided into five blocks of display areas A to E, and the light source color (R) of the same color is turned on by using a separate light source for each block to turn on the panel. Color images of the same color are displayed from the upper side to the lower side, and the color display is performed by sequentially switching to another light source color (B) of the same color for each block.

[0008]

In the above-mentioned conventional light source color switching block sequential method, the light source colors of the same color are sequentially switched for each block, so that the high-speed display field image of R, G, B colors can be seen by human eyes. Although full color is realized by the afterimage, there is a problem that the moving resolution of the moving image is deteriorated particularly when displaying the moving image.

Therefore, an object of the present invention is to solve the above problems in a color liquid crystal display device of a light source color switching system, which is advantageous in terms of resolution, light transmittance and the like with respect to a liquid crystal display device of a color filter system. It is an object of the present invention to provide a driving method of a color liquid crystal display device of a light source color switching system which can obtain high resolution even when displaying an image.

[0010]

In order to achieve the above object, the present invention divides a display surface composed of a plurality of pixels into a plurality of display areas, and light sources of a plurality of colors are arranged in the display areas. In the driving method of the light source color switching color liquid crystal display device for sequentially displaying the image by selectively emitting the light source colors corresponding to the display signals, different light source colors are sequentially displayed in the adjacent display areas of the plurality of display areas. A method of driving a light source color switching color liquid crystal display device is characterized in that light is selectively emitted.

According to the present invention, it is possible to display R, G, and B for all pixels which cannot be realized by the color filter method, and high resolution is realized, and in particular, display (color) signals are displayed in the time axis direction in each display area. Since the color signals are time-divisionally displayed in the vertical scanning direction (that is, in each display area) in addition to the divided display, high resolution can be obtained even when a moving image is displayed.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples.

[Embodiment 1] FIG. 1 shows an example of the configuration of a color liquid crystal display device which carries out the driving method of the present invention. Reference numeral 100 denotes a display surface (display pixel portion) composed of a plurality of pixels.
An image output device 10 outputs the R, G, B signals of the TV or the R, G, B signals of the personal computer. The signal from the image output device 10 is input to the color signal memory circuit 20 and stored for each color signal. When the TV signal is the source source, the input signal to the color signal memory circuit 20 is 60H for one screen.
Although it is a signal of z, the output signal S1 from the color signal memory circuit 20 is output as a high speed signal of 180 Hz. 30
Is an inversion circuit, which converts the signal S1 into an alternating signal by the inversion control signal FI from the control circuit 40 as a measure against the image sticking of the liquid crystal, and outputs the signal S2.

Reference numeral 50 is a vertical scanning circuit (VSR) of the display pixel section 100, 60 is a horizontal scanning circuit (HSR), and 70 is an input image signal S by a pulse signal from the horizontal scanning circuit 20.
2 is a sampling circuit for sampling 2. The signal sampled by the sampling circuit 70 is written in the pixel row of the display pixel unit 100 selected by the vertical scanning circuit 50. Reference numeral 80 denotes a lighting light source switching device, which switches the light source color according to a pulse signal from the control circuit 40.

An outline of the arrangement of the display pixel section 100 and each light source color in this embodiment is shown in FIG. In this embodiment, the display pixel portion is divided into five display areas A to E, and each display area is composed of a plurality of pixel rows (not shown). Light sources of three colors of R, G, and B are arranged in each display area.

The display pixel section 100 has five display areas A to E.
The display color for each display area can be switched by arbitrarily switching the R, G, B light source colors by the lighting light source switching device 80.

In the present invention, different light source colors are selected for the adjacent display areas to emit light.
A predetermined signal S1 corresponding to the display color of each display area is output from the color signal memory circuit 20 and written in the pixel of each display area. Then, the display color of each display area is sequentially switched to perform color display.

The display color in each display area in this embodiment will be described with reference to the timing chart of FIG.

First, R signals for a plurality of pixel rows are written in the display area A, and the R light source arranged in the display area A is turned on. Next, G signals for a plurality of pixel rows are written in the display area B, and the G light source arranged in the display area B is turned on.
Next, B signals for a plurality of pixel rows are written in the display area C, and the B light source arranged in the display area C is turned on. Similarly, the R and G light sources are turned on in the display areas D and E. Then, in each display area, each light source color is sequentially turned on within one vertical scanning period in the order of R, G, B following the above display colors, and R,
G, B three colors are displayed. As a result, it appears to the human eye that full-color display is performed due to afterimages of three colors.

As described above, by adopting the light source color switching system, it is possible to display R, G, and B for all pixels which cannot be realized by the color filter system, and high resolution is realized, and in particular, the time axis is set in each display area. Since the color signals are time-divisionally displayed in the same direction and the color signals are also time-divisionally displayed in the vertical scanning direction (that is, in each display area), high resolution can be obtained even when displaying a moving image.

FIG. 4 shows the signal polarity of the signal S2 inverted by the FI signal from the control circuit 40, which is written in each pixel row in this embodiment.

As shown in FIG. 4, first, in the V11 period of the V1 field, the pixel rows g1 and g of the display area A are displayed.
2, ... Positive polarity signal (+) and non-polarity signal (-) respectively
Are written alternately. Next, the signal polarity is written in the V12 period, being inverted from that in the V11 period. In this way, each pixel row and high-speed field (V11, V12, V13
By inverting the signal polarity every (period), the flicker that depends on the polarity reversal error is reduced and cannot be recognized by human eyes.

[Embodiment 2] As in Embodiment 1, the driving method of the present embodiment is such that, as shown in FIG. 3, different light source colors are selected so as to emit light in adjacent display areas. A predetermined signal S1 corresponding to the display color of each display area is output from the signal memory circuit 20 and written in the pixel of each display area, and the display color of each display area is sequentially switched to perform color display. The difference from the first embodiment is the signal polarity of the inversion signal S2 written in each pixel row.

The signal polarity of the inverted signal S2 written in each pixel row in this embodiment is shown in FIG.

Inverting the signal polarity for each pixel row is the same as in the first embodiment, but inverting the signal polarity in the same pixel row is performed in each field cycle (V1, V1) in this embodiment.
2, V3, ...).

Also in the case of this embodiment, R for each field,
Since the average value of the polarity reversal errors of G and B is integrated by the human eye, flicker cannot be recognized.

[0027]

As described above, according to the present invention,
R, G, B display is possible for all pixels that cannot be realized with the color filter system, and high resolution is realized. In particular, display (color) signals are time-divisionally displayed in the time axis direction in each display area, and vertical scanning direction ( That is, since color signals are also displayed in a time-divisional manner in each display area), high resolution can be obtained even when displaying a moving image.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a system configuration of a color liquid crystal display device according to the present invention.

FIG. 2 is a schematic layout diagram of a display pixel portion and each light source color shown in an embodiment of the present invention.

FIG. 3 is a timing chart for explaining display colors in each display area shown in the embodiment of the present invention.

FIG. 4 is a diagram showing a signal polarity of an inversion signal written in each pixel row in the first embodiment.

FIG. 5 is a diagram showing a signal polarity of an inversion signal written in each pixel row in the second embodiment.

FIG. 6 is a layout view of color filters in a color filter type color liquid crystal display panel.

FIG. 7 is a diagram for explaining a conventional light source color switching frame sequential system.

FIG. 8 is a diagram for explaining a conventional light source color switching block sequential system.

[Explanation of symbols]

 10 image output device 20 color signal memory circuit 30 inversion circuit 40 control circuit 50 vertical scanning circuit 60 horizontal scanning circuit 70 sampling circuit 80 lighting light source switcher 100 display pixel unit

Claims (1)

[Claims] 1. A display surface composed of a plurality of pixels is divided into a plurality of display areas, and light sources of a plurality of colors are respectively arranged in the display areas, and light source colors corresponding to display signals are sequentially selected to emit light to display an image. A driving method of a light source color switching color liquid crystal display device for displaying, characterized in that different light source colors are sequentially selected to emit light in adjacent display areas of the plurality of display areas. Driving method.