JPH01234897A - Driving system for color liquid crystal display device - Google Patents

Abstract

PURPOSE:To reduce the discontinuity of the outline of a LCD of R, G, and B stripe constitution by delaying 1st and 2nd colors by a specific time according to the time of the scanning of one group of stripes of the primary colors. CONSTITUTION:When the color strips are in R, G, and B array, a delay circuit 1 delays an R signal ER by 2DELTA and a delay circuit 2 delays a G signal EG by DELTAin DELTA=T/3 units based upon the scanning time T of the scanning of three color stripes; and a B signal EB is not delayed, and the LCD is thus driven. Consequently, outlines in achromatic color and color close to it are displayed smoothly and the picture quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a driving system for a three-primary color stripe type color liquid crystal display device (hereinafter abbreviated as LCD in this specification).

B0 Outline of the invention Stripe color of three primary colors R, G, B L
When the time to scan a set of R, G, and B stripes on a CD is T, the signal ER for driving R is 2Δ(Δ
= T/3), and the signal Eel that drives B is delayed by Δ
Method of delay.

C0 Conventional Technology There are various pixel arrangements for color LCDs, but for Knee, a striped structure is targeted.

Figure 4 shows the pixel structure of a color LCD.
Figure (a) shows the signal distribution on the horizontal scanning line. Figure 5 (a
) signals drive the R, G, and B picture elements of the color LCD shown in FIG. 4 as follows. In the case of one color,
The R element only emits transmitted light in response to the signal ER.

In white light, ER=Ea=En.

As shown in FIG. 5(b), the signal at a certain time ER(t) is R
Since the color is white, Ec(t) drives the G element and Ee(t) drives the B element.

Problems to be solved by the D0 invention Therefore, the LCD screen has a discontinuous distribution. For example, in the case of a diagonally lined outline on the screen, discontinuity occurs as shown in FIG. In order to reduce this discontinuity, the pitch of picture elements must be made finer,
This will reduce the yield of LCD production. That is, the conventional method has drawbacks in that it either causes a decrease in image quality or a decrease in yield.

[Object of the invention] The object of the invention is to
To improve image quality by reducing contour discontinuities in CD. The purpose of the present invention is to provide a driving method for a color LCD.

E4 Means for Solving the Problems In order to achieve the above object, the driving method of the color LCD of the type mentioned at the beginning according to the present invention is as follows. Change the color by 2△(
Δ=T/3), and the gist includes a step of delaying the second color by Δ.

F0 Effect Most actual screens are not monochromatic, but colors that are close to achromatic colors. That is, the display on the achromatic LCD screen greatly influences the image quality. In FIG. 5(a), the signal distribution on the screen is white (achromatic color), and ER=Ec=Ea. A signal every T on the time axis is used to drive the LCD. Note that T corresponds to one cycle of R, G, and B color picture elements. For this reason, the achromatic figure 5(a)
In the pattern of E(tl)t E(t2)(t2=
Drive R, G, and B with a signal of t+10T), and
The distribution is shown in b).

E(
tz), the signals at the time of E(t2) are R and G.

B, as shown in FIG. 6(b), for example, there is a step across three scanning lines, giving a sense of discontinuity to the diagonal lines.

In the present invention, when the color stripes are arranged in R, G, and B, the scanning time of the three color stripes is T, and the unit is Δ=T/3.The R signal ER is delayed by 2Δ, and the G signal Ec is delayed by Δ. Then, the B signal EB drives the LCD.

G. EXAMPLES The present invention will be explained in more detail below using examples with reference to the drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a block diagram showing the configuration of a delay circuit for implementing the color LCD driving method according to the present invention.
1 represents a 2Δ delay circuit, and 2 represents a Δ delay circuit.

The operation of the above embodiment will be explained below.

For an achromatic gradation change as shown in Figure 2 (a), E8 remains as in (a), Ec is delayed as in (b), and ER is delayed as in (c), so the color As for picture elements, smooth signal distribution is possible as shown in FIG. 2(d).

Even for a black and white diagonal outline as shown in Figure 3(a),
According to the present invention, the reproduced image shown in FIG. 3(b) is obtained,
The brightness changes for each scanning line, reducing the sense of discontinuity in one screen.

As described in detail about the H0 invention, according to the present invention, there is an advantage that outlines of achromatic colors or similar dark colors are displayed smoothly and the quality of one image is improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a delay circuit for implementing the color LCD driving method according to the present invention, Fig. 2 is a diagram illustrating driving for changes in white gradation, and Fig. 3 is a diagram showing diagonal contour lines. FIG. 4 is a diagram showing the pixel structure of a color LCD. FIG. 5 is a diagram illustrating driving in response to a change in white gradation using the conventional method, and FIG. 6 is a diagram illustrating reproduction of a diagonal contour line using the conventional method. 1...2Δ delay circuit, 2...
...Δ delay circuit. Patent applicant Tararion Co., Ltd.

Claims (1)

[Claims] In a three primary color stripe type color liquid crystal display driving method, the first
A driving method for a color liquid crystal display device, comprising a step of delaying a color by 2Δ (Δ=T/3) and delaying a second color by Δ.