JPH1115444A - Liquid crystal display device and liquid crystal control circuit used for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of adjusting change characteristics of display luminance and color for values of the input display data. SOLUTION: This circuit 4 is constituted so as to supply the liquid crystal displaying display data and a synchronizing signal to a data driver 10 and a scan driver 12. In such a case, a data conversion circuit 4 is provided in this circuit 4, and fetches the display data 3 of N bits capable of specifying gradation of 2N pieces (N is natural number), and converts the display data 3 to the display data for displaying one gradation among the gradation more than prescribed 2N pieces according to a prescribed conversion rule to supply them to a data driver 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal display device for performing gradation display and a liquid crystal control circuit for generating display data and a synchronization signal used for the display.

[0002]

2. Description of the Related Art A conventional liquid crystal display device converts an input video signal into display data to be input to a liquid crystal driver, supplies the display data to the liquid crystal driver, and the liquid crystal driver responds to the given display data. A liquid crystal driving voltage is generated and output to a liquid crystal panel to display an image. For example, in a liquid crystal display device that displays eight gradations, the liquid crystal driver selects one of the eight gradation voltages and outputs it to the liquid crystal panel according to the input eight gradation display data.

[0003] A typical method of performing gradation display on a liquid crystal panel using a plurality of levels of gradation voltages as described above includes, for example, the paper essay C-1991 of the IEICE Spring Conference.
480. In this method, the voltage applied to the liquid crystal panel is changed at constant level intervals in response to a change in the value of input display data.

[0004]

In the prior art, the voltage applied to the liquid crystal panel is changed at constant level intervals in response to a change in the value of input display data, and the display luminance of each gradation is balanced. No consideration is given to adjusting (gradation display characteristics). Thus, for example,
It has not been possible to achieve gamma correction for correcting distortion of gradation display characteristics due to device-specific characteristics, or gradation display characteristics and colors suitable for the user's preference or display target image.

An object of the present invention is to provide a liquid crystal display device capable of adjusting the change characteristics of display luminance and color with respect to input display data values.

[0006]

In order to achieve the above object, the present invention provides a liquid crystal panel, a data driver for applying a gradation voltage corresponding to display data supplied to a data line of the liquid crystal panel, A scan driver for applying a selection voltage to a scan line of the liquid crystal panel, a power supply circuit for generating a plurality of grayscale voltages of different voltage levels and supplying the data driver to the data driver; A liquid crystal control circuit for supplying display data and a synchronization signal, wherein the liquid crystal control circuit fetches N-bit display data capable of designating 2 N (N is a natural number) gray scales, and converts the display data. And converting the data into display data for displaying one of more than two predetermined N-th gradations according to a predetermined conversion rule. To provide a liquid crystal display device characterized by having a data conversion means for supplying.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

First, a liquid crystal display device according to a first embodiment of the present invention will be described with reference to FIGS. FIG.
1 is a block diagram of a liquid crystal display device according to the present embodiment. As illustrated, the liquid crystal display device includes a color adjustment control circuit 4, a data driver 10, a scanning driver 12, a liquid crystal panel 14, and a gradation power supply circuit 15.

In the present embodiment, the liquid crystal panel 14 is a TFT type liquid crystal panel that performs color display. The liquid crystal panel 14 has a level of a gray scale voltage applied to a data line and a level of a gray scale voltage applied to a data line. Perform gradation display according to the gradation.

A color adjustment control circuit 4 takes in a display synchronization signal 1, a color setting signal 2, and input display data 3 from an external system such as a personal computer or a workstation (not shown), and displays display data 5 for liquid crystal panel display and a synchronization signal. Generate 6-9. The liquid crystal display data 5, the liquid crystal horizontal synchronization signal 6, and the liquid crystal display data synchronization signal 7 thus generated are supplied to a data driver 10, and the frame synchronization signal 8 and the scanning synchronization signal 9 are supplied to a scanning driver 12.

The scanning driver 12 applies a scanning selection signal 13 to a scanning line of a liquid crystal panel 14 in synchronization with the supplied frame synchronization signal 8 and scanning synchronization signal 9.

The gradation power supply circuit 15 generates a plurality of levels of gradation voltages 116 and supplies them to the data driver 10. In the present embodiment, the number of levels of the gradation voltage 116 is 256 levels.

The data driver 10 fetches the liquid crystal display data 5 in synchronization with the supplied liquid crystal horizontal synchronizing signal 6 and liquid crystal display data synchronizing signal 7, and outputs a gradation voltage 16 having a level corresponding to the liquid crystal display data 5 to a data voltage. 11 is applied to the data line of the liquid crystal panel 14.

FIG. 2 is a block diagram of the color adjustment control circuit 4. As shown, the color adjustment control circuit 4
It has a data conversion circuit 21, a timing control circuit 23, and a characteristic register 24.

The data conversion circuit 21 includes a characteristic register 24
The input display data 3 is converted based on the value of the setting data, and the conversion result is output as the liquid crystal display data 22. In the present embodiment, the input display data 3 includes R (red), G
(Green) and B (blue) are 6-bit display data.
Each of G and B represents 64 gradation information.
Further, the liquid crystal display data 22 as the conversion result includes R, G,
B is 8-bit display data. The specific contents of the conversion will be described later in detail.

The characteristic register 24 sets and changes data in response to a color setting signal 2 supplied from an external system. The data to be set specifies a conversion rule for display data in the data conversion circuit 21.
It is changed according to the type of the display image or the user's instruction.
The liquid crystal display device may be provided with a function that allows the setting value of the characteristic register 24 to be changed according to a user operation.

The timing control circuit 23 generates liquid crystal display synchronizing signals 6 to 9 based on the supplied display synchronizing signal 1, and converts the liquid crystal display synchronizing signals 6 to 9 by the data conversion circuit 21. The liquid crystal display data 22 (R, G, B) thus obtained are output in synchronization. The supplied display synchronization signal 1
Includes a vertical synchronization signal VSYNC and a horizontal synchronization signal HSYNC.
C, and a data synchronous clock DCLK. The output synchronization signals 6 to 9 are a liquid crystal horizontal synchronization signal CL1, a liquid crystal display data synchronization signal CL2, a frame synchronization signal FLM, and a scanning synchronization signal CL3, respectively.

Here, the display operation of the liquid crystal display device will be described with reference to FIG. In the data driver 10,
When the liquid crystal display data 5 is sequentially captured in synchronization with the liquid crystal display data synchronization signal CL2, and the display data for one line is captured, the liquid crystal application voltage 11 corresponding to each display data is output in synchronization with the liquid crystal horizontal synchronization signal CL1. . At this time, the liquid crystal applied voltage 11 is the liquid crystal display data 5 (R,
G, B) is selected from among the gray scale voltages 16 supplied from the gray scale power supply circuit 15. On the other hand, the scanning driver 12 outputs a scanning selection signal 13 (G1 to Gn) for sequentially selecting display lines from the top line in synchronization with the frame synchronization signal FLM and the scanning synchronization signal CL3. As a result, the liquid crystal applied voltage 11 output from the data driver 10 is written to the pixels on the display line selected by the scanning driver 12, and a gradation display is performed. By such a display operation, at most, R, G, and B are each 2
Color display of a total of 16.770,000 colors with 56 gradations is performed.

As shown in FIG. 4, the relationship between the applied voltage and the display luminance of the liquid crystal panel is different between a normally black mode liquid crystal panel and a normally white mode liquid crystal panel. A normally black mode liquid crystal panel has low luminance at a low applied voltage and high luminance at a high applied voltage. This characteristic is represented by an S-shaped curve that saturates in both the low and high applied voltage regions. In a normally white mode liquid crystal panel, the relationship between the applied voltage and the display luminance shows a characteristic opposite (symmetric) to that in the normally black mode. The present invention can be carried out irrespective of the mode of the liquid crystal panel. Hereinafter, it is assumed that the liquid crystal panel 14 is in a normally black mode.

FIG. 5 shows a circuit 25 generated by the gradation power supply circuit 15.
An example of setting a 6-level gradation voltage will be described. In this embodiment,
Each value of the 8-bit liquid crystal display data 5 is associated with each of the 256 levels of gradation voltages V (0) to V (255) on a one-to-one basis. That is, the value 00h (h
Is a symbol indicating hexadecimal notation) and the applied voltage V (0), 01
.., and FFh corresponds to V (255). The data driver 10 selects a gradation voltage corresponding to the value of the supplied liquid crystal display data 5 according to the correspondence, and applies the selected gradation voltage to the data line of the liquid crystal panel 14.

Next, the conversion rule of the display data in the data conversion circuit 21 will be described.

The data conversion circuit 21 has a plurality of conversion rules for associating each value of the 6-bit input display data 3 with the value of the 8-bit liquid crystal display data 5 on a one-to-one basis. Then, the display data is converted using a conversion rule corresponding to the value of the setting data in the characteristic register 24. The conversion rules include, for example, as shown in FIG. 6, values 00h to 3Fh of the input display data 3 are sequentially selected from the value 00h of the liquid crystal display data 22 at four-value intervals.
h,..., FCh. According to such a conversion rule, the data conversion circuit 21 outputs the value of the liquid crystal display data 22 corresponding to the value of the supplied input display data 3 as a conversion result. Further, by switching the conversion rule to be used, the relationship between the input display data 3 and the actual display luminance (gradation display characteristics) can be switched.

FIG. 7 shows an example of the relationship between the input display data 3 according to each conversion rule and the actual display luminance. FIG. 6 (a)
Is a setting example in which the gradation display becomes bright overall, and is suitable for displaying a natural image. FIG. 6B shows a setting example in which the gradation display becomes dark as a whole, and is suitable for displaying computer graphics and text. FIG.
(C) is a setting example in which the relationship between the input display data 3 and the actual display luminance is linear, and this characteristic is obtained when the conversion rule shown in FIG. 5 is used. These conversion rules are selected according to the set value of the characteristic register 24. For example, when the set value is 0, the conversion rule of FIG. 6A is selected, when the set value is 1, the conversion rule of FIG. 6B is selected, and when the set value is 2, the conversion rule of FIG. Is done.

FIG. 8 shows a specific example of the configuration of the data conversion circuit 21. The data conversion circuit 21 shown in the figure includes three blocks corresponding to R, G, and B. Each block has the same configuration, and includes a register group 211 and a plurality of characteristic selectors 2.
12 and a data selector 213. In each block, the register group 211 stores 00h to FCh in advance.
Consists of registers that are individually set. Each of the characteristic selectors 212 is connected to three registers in the register group 211, and selects and outputs the set value of one of the registers in accordance with the set value of the characteristic register 24. The data selector 213 selects and outputs one of the output of the register not connected to the characteristic selector 212 and the output of each characteristic register 212 according to the supplied input display data 3. The data input terminal of each characteristic selector 212 and each register of the register group 211 are connected such that conversion and switching of gradation display characteristics as shown in FIG. 8 are performed. This connection relationship may be different for each of the R, G, and B blocks. By doing so, it is also possible to switch colors.

The number of bits of each of the input display data 3 and the liquid crystal display data 5, the contents and number of conversion rules, and the like can be changed according to the specifications of the liquid crystal display device to be designed.

With the above functions, in the liquid crystal display device of the present embodiment, the gradation is adjusted according to the user's preference, the type of the displayed image (natural image, computer graphics, text, etc.), the characteristic unique to the device, and the like. Display characteristics and hue can be changed.

Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIGS.

In the present embodiment, the contents of the conversion rule of the display data can be arbitrarily changed, and the color adjustment circuit 4 and its control signals are different from those of the first embodiment. The description of the same configuration and operation as in the first embodiment will be omitted.

FIG. 9 shows the configuration of the color adjustment circuit 4 of the present embodiment. As illustrated, the color adjustment circuit 4 of the present embodiment includes a pallet circuit 81, a data conversion circuit 83, and a timing control circuit 23. Timing control circuit 2
3 is the same as in the first embodiment.

The pallet circuit 81 has 64 pallets (registers) corresponding to each value (0h to 3Fh) of the 6-bit input display data 3, and sets the set value of each pallet to the value of the input display data 3. Pallet data 8 in an array corresponding to
The number 2 is supplied to the data conversion circuit 83. In each palette, each value of the 8-bit liquid crystal display data 5 (0h to FC
h) are individually set. Thereby, each value of the input display data 3 of 6 bits and the value of the liquid crystal display data 5 of 8 bits are associated one-to-one. The set value of each pallet is set and changed by a pallet setting signal 2 supplied from an external system.

The data conversion circuit 83 takes in the input display data 3 of 6 bits, selects the value of the liquid crystal display data 5 of 8 bits corresponding to the value of the input display data 3 from the pallet data 82, and selects the value as the display data 22. It is supplied to the timing control circuit 23. Thus, the input display data 3 of 6 bits is converted into the display data 22 of 8 bits.

The data conversion circuit 83 can be constituted by three selectors 831 as shown in FIG. Each selector 831 is provided corresponding to R, G, and B, and pallet data is individually input to 64 data input terminals. Then, the pallet data of the data input terminal corresponding to the value of the input display data 3 input to the select terminal is selected and output.

The pallet circuit 8 according to the pallet setting signal 2
By setting 1, the setting and change of the gradation display characteristics as shown in FIGS. 6A, 6B and 6C are realized. Further, by providing the pallet circuit 81 individually for each of R, G, and B, different settings can be made for each of R, G, and B, thereby enabling setting of the color temperature.

Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to FIGS.

This embodiment differs from the first embodiment in the color adjustment circuit 4 and its input display data. In the present embodiment, the input display data 3 supplied from the external system
Is 8 bits for each of R, G, and B, as in the liquid crystal display data 5, and represents gradation information of 256 gradations. However, due to the gradation display by time division driving, any two of 1021 gradations can be selected.
Display of 56 gradations can be performed.

The color adjustment circuit 4 according to the present embodiment has the configuration shown in FIG.
As shown in (1), it has a data conversion circuit 92, an FRC data generation circuit 91, a timing control circuit 23, and a register 24. Timing control circuit 23 and characteristic register 24
Is the same as in the first embodiment.

The gradation display by the time division driving is realized by the FRC data generation circuit 91 and the data conversion circuit 92. In the present embodiment, as shown in FIG. 12, the gray scale voltage V (n) for displaying the display luminance B (m) and the display luminance B (m)
By selectively applying the gray scale voltage V (n + 1) for displaying (m + 4) to the same pixel for each frame, in addition to the display brightnesses B (m) and B (m + 4), the gray scale brightness between them B (m + 1), B (m + 2) B (m + 3) can be displayed (see FIG. 13). That is, the display luminance B (m) is displayed by applying the gradation voltage V (n) in all of the four frame periods, and the gradation voltage V (n) is applied once.
By applying the gradation voltage V (n + 1) three times, the brightness B
(M + 1) is displayed. Here, the gradation voltages V (n) and V (n + 1) are arbitrary two adjacent levels in the 256-level gradation voltage 16. Furthermore, in the present embodiment, flicker is reduced by making the selection pattern of the gradation voltage applied to each pixel different in four adjacent pixels.

As in the first embodiment, the data conversion circuit 92 has a plurality of display data conversion rules, and utilizes a conversion rule corresponding to the value set in the characteristic register 24 by the color setting signal 2. And conversion of display data. Specifically, the data conversion circuit 92 temporarily converts 8-bit input display data into 10-bit gradation data according to a conversion rule. Then, one or two liquid crystal display data (8 bits) corresponding to the gradation represented by the converted gradation data
Is selectively output in a plurality of frame periods.

The display data conversion rules include, for example, those shown in FIG.
4 is included. In the example of FIG. 14, the input display data of 00h is converted into the gradation data of 000h,
The h input display data is converted to 005h gradation data.

Between the gradation data and the liquid crystal display data,
The correspondence shown in FIG. 14 is predetermined. That is, the gradation data of 000h corresponds to the liquid crystal display data of 00h, and the gradation data of 004h corresponds to the liquid crystal display data of 01h. Further, the gradation data between 000h and 004h corresponds to two liquid crystal display data values of 00h and 01h.

When an intermediate gradation display is performed, two corresponding liquid crystal display data are selectively output for the same pixel according to the FRC data 93. Thus, when the gradation data is 000h, the luminance B (m) change pattern shown in FIG.
When the change pattern of (m + 1) and the gradation data are 002h, the pattern of the luminance B (m + 2) and the gradation data are 00
In the case of 3h, the liquid crystal display data is selected so that the display is performed in the pattern of the luminance B (m + 3). Thereafter, the liquid crystal display data is selected so that the same change pattern is displayed in the four-value cycle of the gradation data.

The liquid crystal display device of the present embodiment switches the display data conversion rules to provide a display luminance as shown in FIGS. 6A, 6B, and 6C as in the first embodiment. Conversion and switching of characteristics can be performed.

Next, specific examples of the FRC data generation circuit 91 and the data conversion circuit 92 will be described.

FIG. 15 shows a configuration example of the FRC data generation circuit 91. As shown, the FRC data generation circuit 9
Reference numeral 1 denotes a synchronization signal 1 (VSYNC, HSYNC, DCLK) including a counter, a flip-flop, and a logic element.
Based on the FRC data 93 (SEL (n + 1), SEL
(N + 2) and SEL (n + 3)). here,
SEL (n + 1), SEL (n + 2), SEL (n +
3) are the luminances B (m + 1) and B shown in FIG.
This is data for giving a change pattern of (m + 2) and B (m + 3).

FIG. 16 shows a configuration example of the data conversion circuit 92. As shown, the data conversion circuit 92 includes R,
It is composed of three blocks corresponding to G and B. Each block has the same configuration and includes a register group 921, a plurality of characteristic selectors 922, a data selector 932, and an FRC selection circuit 924. In each block, the register group 921 includes registers in which data indicating respective values from 00h to 3FCh are individually set in advance. Each characteristic selector 922 is connected to three registers in the register group 921, and selects and outputs the set value of one of the registers in accordance with the set value of the characteristic register 24. The data selector 923 selects and outputs one of an output of a register not connected to the characteristic selector 922 and an output of each characteristic register 922 according to the supplied input display data 3. The data input terminal of each characteristic selector 922 and the registers of the register group 921 are connected so that conversion and switching of gradation display characteristics as shown in FIG. 7 are performed. This connection relationship may be different for each of the R, G, and B blocks. By doing so, it is also possible to switch colors.

The FRC selection circuit 924 outputs the FRC data 9
The liquid crystal display data 5 is generated based on 3 and the 10-bit gradation data output from the data selector 923. As shown in FIG. 17, the FRC selection circuit 924 includes a logic circuit 9241 including a plurality of logic elements, a +1 adder 9242, and a selector 9243. In the gradation data, the upper 8 bits are used as liquid crystal display data, and the lower 2 bits are used to specify a change pattern (see FIG. 12). The selector 9243 receives the upper 8 bits of the gradation data and the data obtained by adding 1 thereto,
One of them is selected and output according to the select data from the logic circuit 9241. The logic circuit 9241 generates the select data based on the lower two bits of the grayscale data and the FRC data 93 so that the grayscale display represented by the grayscale data is performed.

In the liquid crystal display device of this embodiment, the input display data supplied from the external system and the liquid crystal display data supplied to the data driver have the same number of bits.
6A, 6B, and 6C, as in the first embodiment.
The conversion and change of the display luminance characteristic as shown in FIG.

Next, a liquid crystal display device according to a fourth embodiment of the present invention will be described with reference to FIGS.

This embodiment is different from the third embodiment in the color adjustment circuit 4 and the signal for controlling the same. The color adjustment circuit 4 of the present embodiment includes an FRC data generation circuit 91, a pallet circuit 131, a data conversion circuit 133, and a timing control circuit 23, as shown in FIG. F
RC data generation circuit 91 and timing control circuit 23
Is the same as in the third embodiment.

The pallet circuit 131 has 256 pallets (registers) corresponding to each value of the input display data 3 of 8 bits, and sets the setting data of each pallet in an array corresponding to the value of the input display data 3. The data is supplied to the data conversion circuit 133 as pallet data 132. Each pallet has
10-bit gradation data (000h to 3FCh) is individually set. With this setting, each value of the 8-bit input display data 3 and the value of the 10-bit gradation data are associated one-to-one. The set value of each pallet of the pallet circuit 131 is changed by a pallet setting signal 2 supplied from an external system.

The data conversion circuit 133 selects the value of the gradation data corresponding to the value of the input display data 3 supplied from the pallet data 132 supplied from the pallet circuit 131, and displays the gradation of the selected gradation data. The one or two liquid crystal display data corresponding to the FRC data generation circuit 91
Selectively output according to the FRC data supplied from. Thus, similarly to the third embodiment, the gray scale voltage is selected according to the change pattern shown in FIG. 12, and 256 gray scales out of 1021 gray scales are displayed.

FIG. 19 shows a configuration example of the data conversion circuit 133. The data conversion circuit 133 shown in the figure includes three blocks corresponding to R, G, and B, and each block includes a data selector 923 and an FRC selection circuit 924. The data selector 923 and the FRC selection circuit 924 are the same as those in the third embodiment (see FIG. 16). Also, the 1 selected by the data selector 923 according to the input display data.
In the 0-bit gradation data, the upper 8 bits are used as liquid crystal display data, and the lower 2 bits are used to specify a change pattern (see FIG. 12). FRC selection circuit 9
24, the upper 8 bits of the grayscale data and 1 bit based on the lower 2 bits of the grayscale data and the FRC data 93.
And the data obtained by adding. This allows
The gradation display corresponding to the gradation data is performed.

In the liquid crystal display device of this embodiment, the input display data supplied from the external system and the liquid crystal display data supplied to the data driver have the same number of bits.
As in the second embodiment, the display luminance characteristic can be set and changed to an arbitrary characteristic. In addition, by providing the pallet circuit 131 individually for each of R, G, and B, different settings can be made for each of R, G, and B, thereby enabling setting of the color temperature.

[0054]

As described above, according to the present invention, it is possible to provide a liquid crystal display device capable of adjusting the display luminance and color change characteristics with respect to the value of input display data.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a color adjustment control circuit according to the first embodiment.

FIG. 3 is a diagram showing operation timing of a liquid crystal display device.

FIG. 4 is a diagram showing a relationship between applied voltage and luminance of a liquid crystal panel.

FIG. 5 is a diagram showing a relationship between liquid crystal display data of a data driver and luminance.

FIG. 6 is a diagram showing an example of a conversion rule from input display data to liquid crystal display data.

FIG. 7 is a diagram showing a change in the relationship between input display data and luminance due to switching of a conversion rule.

FIG. 8 illustrates a configuration of a data conversion circuit.

FIG. 9 is a block diagram of a color adjustment control circuit according to a second embodiment.

FIG. 10 illustrates a configuration of a data conversion circuit.

FIG. 11 is a block diagram of a color adjustment control circuit according to a third embodiment.

FIG. 12 is a diagram showing a method of displaying an intermediate gradation by time-division driving.

FIG. 13 is a diagram showing a relationship between applied voltage and luminance of a liquid crystal panel.

FIG. 14 is a diagram showing an example of a conversion rule from input display data to liquid crystal display data.

FIG. 15 is a diagram showing a configuration of an FRC data generation circuit.

FIG. 16 illustrates a configuration of a data conversion circuit.

FIG. 17 is a diagram showing a configuration of an FRC selection circuit.

FIG. 18 is a block diagram of a color adjustment control circuit according to a fourth embodiment.

FIG. 19 illustrates a configuration of a data conversion circuit.

[Explanation of symbols]

1 ... Display synchronization signal, 2 ... Color setting signal, 3 ... Input display data, 4 ... Color adjustment control circuit, 5 ... Liquid crystal display data, 6 ... Liquid crystal horizontal synchronization signal, 7: liquid crystal display data synchronization signal, 8: frame synchronization signal indicating the display frame period, 9: scanning synchronization signal, 10: data driver,
11: applied voltage of liquid crystal, 12: scanning driver, 13:
Scanning selection signal, 14: liquid crystal panel, 15: gradation power supply circuit, 16: gradation voltage, 21: data conversion circuit, 22
... Display data converted by the data conversion circuit 21, 23 ...
Timing control circuit, 24: characteristic register, 81: palette circuit, 82: palette data, 83: data conversion circuit, 91: FRC data generation circuit, 92: data conversion circuit, 93: FRC data, 131: palette circuit, 132: palette data, 133: data conversion circuit.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor ▲ Shin Hiroyuki No. 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory Co., Ltd. No. 20-1, Hitachi Semiconductor Co., Ltd. Semiconductor Division (72) Inventor Hiroshi Kurihara 3300 Hayano, Mobara-shi, Chiba Pref. Electronic Device Division, Hitachi, Ltd.

Claims (10)

[Claims] 1. A liquid crystal panel, a data driver for applying a gradation voltage corresponding to display data supplied to a data line of the liquid crystal panel, and a scan driver for applying a selection voltage to a scan line of the liquid crystal panel. A power supply circuit that generates a plurality of grayscale voltages having different voltage levels and supplies the data driver to the data driver; and a liquid crystal control circuit that supplies display data and a synchronization signal for liquid crystal display to the data driver and the scan driver. The liquid crystal control circuit fetches N-bit display data capable of designating 2 N (N is a natural number) gradations, and converts the display data into a predetermined 2 according to a predetermined conversion rule.
A liquid crystal display device comprising: data conversion means for converting one of the gradations, which is more than N to the display power, into display data for display and supplying the display data to the data driver. 2. The liquid crystal display device according to claim 1, wherein the gray scale voltage generated by the power supply circuit is 2 M (M)
Is a natural number that satisfies N <M). The conversion rule is a pair of each value of the N-bit display data to be taken and the value of the M-bit display data as a conversion result of the data conversion unit. 1. A liquid crystal display device, which corresponds to 1. 3. The liquid crystal display device according to claim 2, wherein a plurality of types of said conversion rules are determined, and said data conversion means converts one conversion rule specified by input control information into a conversion rule for display data. A liquid crystal display device characterized by being used for: 4. The liquid crystal display device according to claim 2, wherein the correspondence between the N-bit display data and the M-bit display data in the conversion rule is changed according to input control information. Liquid crystal display. 5. The liquid crystal display device according to claim 1, wherein the gray scale voltage generated by the power supply circuit has 2 N levels, and the conversion rule is a level of N-bit display data to be captured. N-bit display for time-divisionally displaying each value and one of more than a predetermined 2 N number of tones, which is a conversion result of the data conversion means, in a plurality of periods. A liquid crystal display device for associating a data arrangement with a data arrangement. 6. The liquid crystal display device according to claim 5, wherein a plurality of types of said conversion rules are determined, and said data conversion means converts one conversion rule specified by input control information into display data. A liquid crystal display device characterized by being used for: 7. The liquid crystal display device according to claim 5, wherein the correspondence between the N-bit display data and the arrangement of the N-bit display data in the conversion rule is changed according to input control information. Liquid crystal display device. 8. A liquid crystal panel, a data driver for applying a gradation voltage corresponding to display data supplied to a data line of the liquid crystal panel, and a scan driver for applying a selection voltage to a scan line of the liquid crystal panel. And a power supply circuit for generating a plurality of grayscale voltages having different voltage levels and supplying the grayscale voltages to the data driver, and supplies display data and a synchronization signal for liquid crystal display to the data driver and the scan driver. In the liquid crystal control circuit, N-bit (N is a natural number) gray scale display data of N bits that can be designated is taken in, and the display data is converted into a predetermined 2 N power according to a predetermined conversion rule. It is characterized in that it comprises a data conversion means for converting one of the gradations out of the number into display data for displaying and supplying the display data to the data driver. LCD control circuit. 9. The liquid crystal control circuit according to claim 8, wherein the gradation voltage generated by the power supply circuit is 2 M (M)
Is a natural number that satisfies N <M). The conversion rule is a pair of each value of the N-bit display data to be taken and the value of the M-bit display data as a conversion result of the data conversion unit. 1. A liquid crystal control circuit, which corresponds to 1. 10. The liquid crystal control circuit according to claim 8, wherein the gray scale voltage generated by the power supply circuit has 2 N levels, and the conversion rule is a level of N-bit display data to be captured. N bits for displaying each value and a corresponding one of more than 2 predetermined N tones as a conversion result of the data conversion means in a time-division manner over a plurality of periods A liquid crystal control circuit for associating the display data with the display data sequence.