JPH09198011A - Liquid crystal display controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce a multilevel display corresponding to the characteristic of liquid crystal and to make a circuit scale small by outputting display signals while selecting a gradation pattern stored in a gradation pattern storage part based on gradation signals to be inputted. SOLUTION: A ROM 10 as a gradation pattern storage part stores preliminarily gradation patterns of kinds corresponding to the number of gradation steps of gradation signals Sr, Sg, Sb as to respective colors R(red), G(green) and B(blue) from the outside. Moreover, a frame thinning control part 20 outputs display control signals Dr, Dg, Db by selecting the gradation pattern signal P stored in the ROM 10 based on the gradation signals Sr, Sg, Sb. Then, a CRT timing, etc., are inputted to an LCD timing control part 30, which outputs a video signal CP and a frame signal FRM to a liquid crystal display part (an LCD) 40. In this case, gradation pattern signals Ps to be made to be stored in the ROM 10 are made to be signals matched to the characteristic of the liquid crystal display part 40 and to the visual sense of the observer of the LCD 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display control device for inputting R (red), G (green), and B (blue) display data (RGB data) to a liquid crystal panel from the outside and performing color display. Regarding

[0002]

2. Description of the Related Art In a liquid crystal display control device of this type, RGB data is output as it is to the liquid crystal panel by simply adjusting the display data output timing peculiar to the liquid crystal panel. Reproducibility is often not obtained. On the other hand, for example, Japanese Patent Application Laid-Open No. 5-232449 discloses a liquid crystal display control device intended to reproduce gradation display according to the characteristics of liquid crystal. This liquid crystal display control device includes a correction reference data table, a calculation unit that performs calculation on the reference data from the correction reference data table,
A selector for selecting reference data and calculation result data by the calculation unit, a gradation pattern generation unit for generating a plurality of selector switching timings, and a correction for storing data for selecting one of the plurality of switching timings. It has an attribute data table and a selection signal generating section for selecting a switching timing based on the attribute data output from the correction attribute data table and generating a selector selection signal. Then, display data matching the characteristics of the liquid crystal panel is stored in the correction reference data table and the correction attribute data table, and a plurality of types of gradation patterns corresponding to these are stored in the pattern generation unit, and input. The correction reference data table and the correction attribute data table are accessed for each data, and gradation display between the reference data and the calculation result data by the calculation unit is performed.

[0003]

The liquid crystal display control device described in the above publication stores the correction reference data according to the number of gradation steps of the input data, the storage of the correction attribute data for selecting the gradation pattern, and the reference. It is necessary to store a gradation pattern that determines the timing for selecting either data or calculation data, and a circuit for controlling these and a calculation circuit are also necessary. That is, although this conventional liquid crystal display control device can reproduce gradation display according to the characteristics of the liquid crystal,
As described above, the R, G, and B display data each have a complicated configuration, a large circuit scale, and a high cost. Further, if the structure is complicated, there is a problem in terms of processing speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display control device having a simple and inexpensive structure which can reproduce gradation display according to the characteristics of liquid crystal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display control device which can reproduce a gradation display according to the characteristics of liquid crystal and has a high processing speed.

[0006]

According to the present invention, a gradation pattern storage unit storing in advance a gradation pattern of a type corresponding to the number of gradation steps of the gradation signal, and a gradation signal input based on the gradation signal. A liquid crystal display control device having a frame thinning control unit for selecting a gradation pattern stored in the gradation pattern storage unit and outputting a display control signal is obtained.

Further, according to the present invention, the frame thinning control section inputs a gradation pattern from the selector for selecting a gradation pattern on the basis of the input gradation signal and the gradation pattern storage section and outputs all the gradation patterns. The gradation patterns of various types are arranged side by side in a ring shape and stored, and the gradation patterns stored in the ring shape are shifted based on the input frame signal so that the constituent elements of the gradation pattern selected by the selector are sequentially turned one by one. A gradation pattern shift register for outputting to the selector, and the selector further outputs a display control signal based on an input gradation signal and a gradation pattern input from the gradation pattern shift register for each constituent element. The liquid crystal display control device that outputs is obtained.

Further, according to the present invention, the liquid crystal display control device can be obtained in which the gradation pattern storage section rewritably stores the gradation pattern.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the present liquid crystal display control device. Referring to FIG. 1, the present liquid crystal display control device is provided with R (red), G (green), and B from the outside of the device.
ROM 10 as a gradation pattern storage unit that stores in advance gradation patterns of types corresponding to the gradation levels of the gradation signals Sr, Sg, and Sb for each (blue), and the input gradation signals Sr, Sg. , And RO based on Sb
The frame thinning control unit 20 that selects the gradation pattern signal P stored in M10 and outputs the display control signals Dr, Dg, and Db, the CRT timing signal TM, and the like are input, while the liquid crystal display unit (LCD) 40. To video signal CP,
The LCD timing control unit 30 outputs the frame signal FRM. The gradation pattern signal P stored in the ROM 10 is based on various characteristics of the liquid crystal display unit 40 and the LCD 40.
It should be adjusted to the visual sensitivity of the observer.

FIG. 2 is a block diagram showing the internal structure of the frame thinning control section 20. Referring to FIG. 2, the frame thinning control unit 20 controls the grayscale signals Sr, Sg, and Sb.
Selector 22 for selecting the gradation pattern signal P based on
Then, the gradation pattern signal P is input from the gradation pattern storage unit 10, all kinds of gradation patterns are arranged side by side in a ring shape, and the gradation patterns stored in this ring shape are stored based on the input frame signal FRM. Shift to selector 22
And a gradation pattern shift register 21 for sequentially outputting the component signal PB of the gradation pattern selected by the selector 22 to the selector 22 one by one. The selector 22 receives the display control signals Dr, Dg, and D based on the input grayscale signals Sr, Sg, and Sb and the grayscale pattern signal P input from the grayscale pattern shift register 21 one by one.
b is output.

Next, the operation of the present liquid crystal display control device will be described with reference to FIGS. 1 and 2.

The gradation pattern stored in the ROM 10 in advance depends on the characteristics of the LCD 40, the visual sensitivity of the observer, etc., as a result of the experiment and measurement of R, G, and B separately. is there. In the present embodiment, when the gradation signals Sr, Sg, and Sb are all represented by three gradations (0, 1, 2), a pattern representing 0 gradation, a pattern representing 1 gradation, and The pattern representing the gradation of 2 is stored in the ROM 10. As an example of this, in the present embodiment, a gradation pattern (111) in which three frames are “1” as a gradation pattern of 0 and the next frame is “0”.
0), the gradation pattern of 1 is “0” for one frame, and the gradation pattern of the next frame is “1” (0
1) A gradation pattern (00) in which two frames are “0” between the two frames and the next frame is “1”
1) is stored in the ROM 10.

Now, when this device is turned on, the LCD timing control unit 30 which receives the CRT timing signal TM receives R
The frame signal FRM is output to the OM 10 and the frame thinning control unit 20.

In the frame thinning control section 20, the selector 22 selects any one of the above three patterns as the gradation pattern signal P based on the gradation signals Sr, Sg and Sb. The gradation shift pattern register 21 is a ROM
The gradation pattern signal P is input from 10, and three kinds of gradation patterns (1110), (01), and (001) are arranged side by side in a ring shape and stored. Along with this, the gradation pattern signal P stored in the ring shape is inputted to the frame signal FR to be inputted.
By shifting based on M, the component signal PB of the gradation pattern signal P selected by the selector 22 is sequentially output to the selector 22 one by one. For example, the gradation signal S
If r is the gradation of 1, the gradation pattern signal P representing the gradation of 1 is (01), so 0 is output first, and when the next frame signal FRM comes, the gradation shift pattern register 21 The value of is shifted and 1 is output. As described above, the selector 22 of the frame thinning-out control unit 20 determines, based on the input grayscale signals Sr, Sg, and Sb and the grayscale pattern signal P input from the grayscale pattern shift register 21 for each component. Display control signals Dr, Dg,
And Db are output to the LCD timing control unit 30.

The LCD timing control section 30 includes a CRT timing signal TM and display control signals Dr, Dg,
And Db based on the video signal CP and the frame signal F.
The RM is displayed on the LCD 40 for gradation display.

In the present embodiment, the ROM is taken as an example of the gradation pattern storage unit, but the gradation pattern storage unit according to the present invention is E so that the gradation pattern can be rewritten.
You may comprise by EPROM etc.

[0018]

According to the liquid crystal display control device of the present invention, a gradation pattern storage section that stores in advance a gradation pattern of a type corresponding to the number of gradation steps of the gradation signal, and a gradation pattern based on the input gradation signal. Since it has a configuration including a frame thinning control unit that selects a gradation pattern stored in the tone pattern storage unit and outputs a display control signal, a correction reference data table, a correction attribute table, which the conventional device has, And a calculation unit is unnecessary. Therefore, it is of course possible to reproduce the gradation display according to the characteristics of the liquid crystal, and the circuit scale is small, and the structure is simple and inexpensive. Also, the algorithm is simple,
High processing speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a liquid crystal display control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the inside of a frame thinning control unit in the liquid crystal display control device shown in FIG.

[Explanation of symbols]

 10 ROM 20 Frame thinning control unit 30 LCD timing control unit 40 Liquid crystal display unit (LCD) CP video signal Dr, Dg, Db display control signal FRM frame signal P gradation pattern signal PB component signal Sr, Sg, Sb gradation signal TM CRT timing signal

Claims (3)

[Claims] 1. A gradation pattern storage section in which a gradation pattern of a type corresponding to the number of gradation steps of a gradation signal is stored in advance, and a floor stored in the gradation pattern storage section based on an input gradation signal. A liquid crystal display control device, comprising: a frame thinning control unit that selects a tone pattern and outputs a display control signal. 2. The frame thinning-out control unit inputs a gradation pattern from a selector that selects a gradation pattern based on an input gradation signal, and a gradation pattern of all types by inputting the gradation pattern from the gradation pattern storage unit. Are arranged side by side in a ring shape, and the gradation patterns stored in the ring shape are shifted based on the input frame signal and the constituent elements of the gradation pattern selected by the selector are sequentially output to the selector one by one. A gradation pattern shift register is provided, and the selector outputs a display control signal based on an input gradation signal and a gradation pattern input from the gradation pattern shift register one by one. The liquid crystal display control device according to claim 1. 3. The liquid crystal display control device according to claim 1, wherein the gradation pattern storage unit rewritably stores the gradation pattern.