WO2005088591A1

WO2005088591A1 - Gamma correction circuit, display panel, and display having them

Info

Publication number: WO2005088591A1
Application number: PCT/JP2005/004641
Authority: WO
Inventors: Kenichi Nakata
Original assignee: Rohm Co., Ltd
Priority date: 2004-03-17
Filing date: 2005-03-16
Publication date: 2005-09-22
Also published as: CN1954352A; KR20060130231A; JP2005269110A; TW200540794A

Abstract

A display having a display panel the color balance of which can be adjusted. The display (1) comprises a gamma correcting circuit (5a) including a gamma data output circuit (11a) for outputting gamma correction data for each color of RGB, registers (121 to 12m) receiving and holding the gamma correction data, and D/A converters (DAC) (131 to 13m) for converting the data in the registers (121 to 12m) into analog voltages and outputting gamma correction setting voltages VI1 to VIm, a source driver (6) receiving image data, selecting gamma correction setting voltages or their interpolation voltages in accordance with the image data, and thereby outputting a corrected image voltage, and a display panel (7) in which gate lines are connected to display elements each displaying one color are driven by a gate driver (8) and the corrected image voltage from the source driver (6) is inputted into a source line.

Description

Specification

Gamma correction circuit, display panel, and display device having the same

Technical field

The present invention relates to a gamma correction circuit and a display panel. Further, the present invention relates to a display device such as a liquid crystal display device including a gamma correction circuit and a display panel. Background art

[0002] In general, a display panel of a display device such as a liquid crystal display device has a non-linear correlation between an applied voltage of a display element and luminance, that is, a gamma characteristic. Figure 5 shows general gamma characteristics. A solid line curve A in FIG. 5 shows the characteristics of the liquid crystal display element when the image voltage (for example, V or V) is directly applied without correction (gamma correction) (that is, gamma characteristics). In the figure, the horizontal axis represents the applied voltage, and the vertical axis represents the relative luminance (that is, the light transmittance of the liquid crystal). Now, the image voltage (for example, V or V) is

If the applied voltage is used as it is without 1 m correction, a good image cannot be displayed due to the nonlinear correlation. Therefore, in order to display a good image, a corrected image obtained by gamma-correcting the image voltage (for example, V or V) so that the image voltage and the luminance are along a dashed straight line B having a linear correlation. Voltage (e.g. VI or V

1 m 1

I) is used as the applied voltage.

As gamma correction circuits for performing gamma correction in a liquid crystal display device as described above, for example, those disclosed in Patent Documents 1, 2, and 3 are known. Further, the applicant of the present application has proposed in Patent Document 4 a gamma correction circuit based on those disclosed in these Patent Documents as background art. FIG. 6 shows a liquid crystal display device including a gamma correction circuit similar to that of Patent Document 4. This liquid crystal display device 101 has a gun for outputting gamma correction setting voltages VI to VI.

1 m

Inputting the gamma correction circuit 105a and the n-bit (eg, 8-bit) image data Di, and selecting the corresponding gamma correction setting voltages VI to VI or their interpolation voltages described later.

1 m

The source driver 6 outputs the corrected image voltage Vo as an applied voltage to the display panel 107 described below for each source line, the display panel 107, the gate driver 8 that drives the gate lines of the display panel 107, the gamma Non-volatile memory for storing correction data 1 09, including.

[0004] The gamma correction circuit 105a converts serial gamma correction data, which is also input via the input terminal SD, into digital data corresponding to the gamma correction setting voltages VI to VI.

1 m

A gamma correction data output circuit 11 la for converting and outputting L-bit (for example, 10-bit) parallel gamma correction data, and m (for example, 9) registers 12 for inputting and holding the parallel gamma correction data To 12 and the data output from registers 12 to 12

1 m 1 m

Convert to analog voltage, e.g. 10-bit DZA conversion (DAC) 13 to 13; D

1 m

Input analog voltage output from ZA converter (DAC) 13 to 13 to increase current capability.

1 m

Buffers 14 to 14 which output gamma correction setting voltages VI to VI. Also

1 m 1 m

The gamma correction data output circuit llla stores the gamma correction data in the nonvolatile memory 109, and retrieves the data from the nonvolatile memory 109 as needed.

[0005] The source driver 6 uniformly compensates between adjacent voltages (for example, between VI and VI) in the gamma correction set voltage VI to VI which is the output of the gamma correction circuit 105a by m resistors. A resistance ladder 15 that generates an interpolation voltage by using the gamma correction setting voltages VI to VI or an image voltage V corrected by selecting those interpolation voltages according to the n-bit image data Di.

1 m

and a decoder 16 for outputting o. The display panel 107 to which the corrected image voltage Vo is input has 2 ⁿ gradations. That is, if n is 8, the gray scale of the display panel 107 is 256. The value of m, is calculated as 2 ⁿ / (m-1). That is, if n is 8 and m is 9, m 'is 32. For example, if the value of the image data Di is 0, the corrected image voltage Vo is a voltage equal to VI, and if the value of the image data Di is 16, the corrected image voltage Vo is the center voltage between VI and VI. .

1 2

[0006] At the time of adjustment, the display on the display panel 107 is checked in real time, and the gamma correction setting voltages VI to VI are adjusted by inputting serial gamma correction data to the gamma correction circuit 105a from the outside via the input terminal SD. It is adjusted to become. Once the adjustment is complete

1 m

The gamma correction data in the adjustment completed state is stored in the non-volatile memory 109, and thereafter, the gamma correction data stored in the non-volatile memory 109 is used.

Next, FIG. 7 shows a liquid crystal display device having the same components as the other embodiments in Patent Document 4. This liquid crystal display device 102 is substantially the same as the liquid crystal display device 101 described above. It includes a source driver 6, a display panel 107, a gate driver 8, and a nonvolatile memory 109 having the same circuit configuration or the same structure, and includes a gamma correction circuit 105b having a different configuration from the gamma correction circuit 105a instead of the gamma correction circuit 105a. The gamma correction circuit 105b includes a gamma correction data output circuit 11 lb and two sets of m registers 12 that hold data corresponding to odd-numbered Z-even numbers of horizontal lines (horizontal scanning lines) of the display panel 107. a to 12a, 12b to 12b

1 mlm or one of the two sets is selected and output to DZA converters 13 to 13 described later.

1 m

Horizontal synchronization which is a synchronization signal of horizontal lines of the display panel 107

1 m

The signal HS is input, and the selectors 117 to 117 are selected according to the odd number Z even number of the horizontal line.

1 m Selector control circuit 118 for switching control, DZA conversions 13 to 13, buffer 14

1 m 1 to 14. The gamma correction circuit 105b uses the functions of the gamma correction circuit 105a to generate gamma correction setting voltages VI to VI according to the odd-numbered Z even-numbered horizontal lines.

Since it can be changed at a high speed of 1 m, it is suitable for, for example, a line inversion driving method in which positive and negative polarities are inverted on upper and lower horizontal lines.

Next, FIG. 8 shows a liquid crystal display device having components similar to those of the other embodiments in Patent Document 4. The liquid crystal display device 103 includes a source driver 6, a display panel 107, a gate driver 8, and a nonvolatile memory 109 having substantially the same circuit configuration or the same structure as the liquid crystal display devices 101 and 102, and performs gamma correction. A gamma correction circuit 105c having a different configuration from that of the circuits 105a and 105b is included. The gamma correction circuit 105c includes a gamma correction data output circuit 111b, and two sets of m registers 12a to 12a, 12b to 12b that hold data corresponding to odd-numbered Z-even-numbered horizontal lines. Directly to them

1 ml m

Connected two sets of m DZA converters 13a to 13a, 13b to 13b, whichever

1 ml m

Selectors 117 to 1 for switching and selecting one of the sets and outputting the same to buffers 14 to 14 described later.

1 m 1

17 and a selector system that controls switching of the selectors 117 to 117 by the horizontal synchronization signal HS m 1 m

It includes a control circuit 118 and the knockers 14 to 14. This gamma correction circuit 105c

1 m

Similar to the correction circuit 105b, for example, it is suitable for a driving method of a line inversion method in which the polarity of the upper and lower horizontal lines is inverted, but gamma correction setting is further performed according to the odd number z even number of the horizontal line. Since the voltages VI to VI can be changed, the display panel 10

1 m

It is more suitable for those having a high frequency of 7 horizontal lines. Patent Document 1: Japanese Patent Application Laid-Open No. 10-108040

Patent Document 2: JP-A-11 32237

Patent Document 3: US Pat. No. 5,796,384

Patent Document 4: Japanese Patent Application No. 2002-326266 (Japanese Patent Application Laid-Open No. 2004-165749;)

Disclosure of the invention

Problems to be solved by the invention

As described above, in the liquid crystal display devices 101, 102, and 103, appropriate gamma correction is performed by adjusting the gamma correction setting voltages VI to VI in accordance with the individual display panels 107.

1 m

Done.

[0011] In recent years, color liquid crystal display devices have become widespread, and there is a demand for a larger display screen and higher quality. As shown in FIG. 9 (a), a display panel of a color liquid crystal display device has a plurality of display elements arranged two-dimensionally for each color of RGB, and R (red) and G (green) are arranged in a column direction. , B are arranged in stripes in the order of blue (blue). FIG. 2B is a circuit diagram corresponding to the array diagram of FIG. The display elements in one row are connected to one gate line Gi (or Gi or the like), and are provided in the order of R, G, and B colors. Display element in one column

+ 1

Is connected to one source line Sj (or Si, etc.), and also has one color power of RGB.

+ 1

[0012] In order to display a good image, it is necessary to balance the luminance of each of the RGB colors (ie, the color balance) so as not to shift to a specific color. However, when the color balance is broken due to a characteristic shift of a backlight or a color filter when manufacturing a display panel, a phenomenon that the color shifts to a specific color slightly and, for example, the entire image becomes bluish is generated. Occur. The inventor of the present application has considered a means for relatively easily adjusting the color balance of the display panel for suppressing the above-mentioned phenomenon in order to further improve the quality of an image in consideration of the progress of a large screen display. We focused on improving the gamma correction circuit and display panel.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gamma correction circuit capable of adjusting the color balance of a display panel, a display panel, and a display device including the same. To provide.

Means for solving the problem A gamma correction circuit according to a preferred embodiment of the present invention is a gamma correction circuit that outputs a gamma correction setting voltage to correct an image voltage according to a non-linear correlation between a voltage applied to a display element and luminance. There is a gamma correction data output circuit that outputs a plurality of gamma correction data for each of the RGB colors, a plurality of registers that inputs and holds a plurality of gamma correction data, and the data of the plurality of registers to analog voltages. And a plurality of DZA converters for converting and outputting a gamma correction setting voltage.

[0015] The gamma correction data output circuit of the gamma correction circuit desirably outputs a plurality of gamma correction data input from outside for each of RGB colors at the time of gamma correction setting voltage adjustment, and adjusts the gamma correction setting voltage. Is for extracting and outputting a plurality of gamma correction data for each color of RGB from the non-volatile memory.

[0016] Preferably, the gamma correction data output circuit of the gamma correction circuit outputs a plurality of gamma correction data for each of the RGB colors sequentially in accordance with the horizontal synchronization signal of the display panel. Alternatively, preferably, the plurality of registers of the gamma correction circuit are provided for each color of RGB, and the data of the plurality of registers of each color are sequentially selected by the horizontal synchronization signal of the display panel, and the DZA conversion is performed. Entered in ^. Alternatively, preferably, the plurality of registers and the plurality of DZA converters of the gamma correction circuit are provided for each color of RGB, and the gamma correction setting voltage of each color is sequentially selected by the horizontal synchronization signal of the display panel. Is output.

In a display panel according to another preferred embodiment of the present invention, a plurality of display elements are arranged two-dimensionally for each of RGB colors, and a source is supplied to a plurality of display elements connected to a selected gate line. A display panel to which a line applied voltage is applied.A plurality of display elements of one color are connected to each gate line, and a plurality of display elements of each color are connected in order by a horizontal synchronization signal. The line is selected.

A display device according to still another preferred embodiment of the present invention includes the above-described gamma correction circuit according to a preferred embodiment of the present invention, a gamma correction setting voltage corresponding to the input of image data, and a corresponding gamma correction setting voltage. A source driver for outputting a corrected image voltage by selecting the interpolation voltage of the above, a gate line driven by a gate driver, and the corrected image voltage of the source driver being input to the source line. Another embodiment And the above-described display panel.

The invention's effect

According to a preferred embodiment of the present invention, the gamma correction circuit is provided with a gamma correction data output circuit that outputs a plurality of gamma correction data for each of the RGB colors. When used together with a display panel to which a plurality of powerful display elements are connected, gamma correction can be performed for each of the RGB colors. As a result, the color balance of the display panel can be adjusted. In the display panel, a plurality of display elements having one color strength are connected to each gate line, and a gate line to which a plurality of display elements of each color are sequentially connected is selected by a horizontal synchronization signal. Therefore, the color balance can be adjusted by performing gamma correction for each of the RGB colors using this gamma correction circuit. The display device including the gamma correction circuit and the display panel can display a good image without shifting to a specific color.

Brief Description of Drawings

FIG. 1 is a circuit diagram of a display device according to a preferred embodiment of the present invention.

FIG. 2 is a view showing a display panel of the above, in which (a) is an arrangement diagram of RGB display elements and (b) is a circuit diagram corresponding thereto.

FIG. 3 is a circuit diagram of a display device according to another preferred embodiment of the present invention.

FIG. 4 is a circuit diagram of a display device according to still another preferred embodiment of the present invention.

FIG. 5 is a diagram showing general gamma characteristics.

FIG. 6 is a circuit diagram of a display device of the background art.

FIG. 7 is a circuit diagram of another display device of the background art.

FIG. 8 is a circuit diagram of still another display device of the background art.

FIG. 9 shows a color display panel of the background art, where (a) is an arrangement diagram of RGB display elements and (b) is a circuit diagram corresponding thereto.

Explanation of symbols

[0021] 1, 2, 3 liquid crystal display devices (display devices)

5a, 5b, 5c gamma correction circuit

6 Source dryno 7 Display panel

8 Gate driver

9 Non-volatile memory

l la, l ib gamma correction data output circuit

12 to 12 Register in gamma correction circuit 5a

1 m

12R to 12R R register in gamma correction circuit 5b, 5c

1 m

G register in 12G to 12G gamma correction circuit 5b, 5c

1 m

12B to 12B B color register in gamma correction circuit 5b, 5c

1 m

13 ~ 13 DZA conversion in gamma correction circuit 5a, 5b

1 m

13R to 13R DZA transformation of R color in gamma correction circuit 5c ^^

1 m

13G to 13G DZ A transformation of G color in gamma correction circuit 5c ^^

1 m

13B to 13B DZ A transformation of B color in gamma correction circuit 5c ^^

1 m

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of a liquid crystal display device 1 according to a preferred embodiment of the present invention. The liquid crystal display device 1 includes a gamma correction circuit 5a that outputs gamma correction setting voltages VI to VI for correcting an image voltage according to a nonlinear correlation between an applied voltage of a liquid crystal display element and luminance.

1 m

And n-bit (eg, 8-bit) image data Di and input the corresponding gamma correction setting voltages VI to VI or their interpolation voltages to select the corrected image power Di.

1 m

A source driver 6 that outputs a voltage Vo as an applied voltage to a display panel 7 described below for each source line, a display panel 7 having a color liquid crystal display element, and a gate driver 8 that drives a gate line of the display panel 7. And a nonvolatile memory 9 for storing gamma correction data. Here, the source driver 6 and the gate driver 8 have substantially the same circuit configuration as the liquid crystal display device 101 described above.

The gamma correction circuit 5a converts serial gamma correction data sequentially input for each color of RGB via the external force input terminal SD into gamma correction setting voltages VI to VI.

A gamma correction data output circuit 11a that converts L-bit (eg, 10-bit) parallel gamma correction data that is 1 m digital data and outputs the converted data. M (for example, 9) registers 12 to 12 for inputting and holding data, and registers 12 to 12

1 m 1

12 converts the data output to an analog voltage, for example, a 10-bit DZA converter (DAC) 13 to 13 and an analog voltage output from the DZA converter (DAC) 13 to 13

1 m 1 m

Input and output the gamma correction setting voltages VI to VI by increasing the current capability.

1 m

4 to 14 are included. Also, the gamma correction data output circuit 11a provides a gamma correction setting

1 m

When adjusting the pressures VI to VI, adjust the RGB colors through the external color input terminal SD.

1 m

The serial gamma correction data that is input sequentially is converted to parallel gamma correction data and output to registers 12 through 12, and the gamma correction data for each RGB color is converted.

1 m

Data (ie, R gamma correction data, G gamma correction data, and B gamma correction data) are stored in the nonvolatile memory 9. After adjusting the gamma correction setting voltages VI to VI, the gamma correction data output circuit 11a outputs the horizontal synchronizing signal HS signal of the display panel 7.

1 m

The gamma correction data stored in the non-volatile memory 9 is extracted for each of the RGB colors in order, and output to the registers 12 to 12.

1 m

As shown in FIG. 2 (a), the display panel 7 has a plurality of display elements two-dimensionally arranged for each of the RGB colors, and is arranged in the row direction in a stripe shape in the order of R, G, and B colors. They are arranged. FIG. 2B is a circuit diagram corresponding to the arrangement diagram of FIG. Each row, that is, each gate line Gi (or Gi, etc.) has a plurality of display elements of one color strength of RGB.

+ 1

The child is connected. One column, that is, one source line ¾ (or ¾ etc.) has R

+ 1

, G, and B are connected to a plurality of display elements in this order. The display panel 7 includes a gate line Gi (or Gi or the like) to which a plurality of display elements of each color are sequentially connected by a horizontal synchronization signal HS.

+ 1

) Is selected by the gate driver 8 and the selected gate line Gi (or Gi, etc.) is selected.

+1 Applied voltage of source line 等 (or ¾ etc.) is applied to multiple connected display elements

+ 1

Next, the operation when adjusting the gamma correction setting voltages VI to VI and the operation after the adjustment

1 m

Will be described. First, the case of adjusting the gamma correction setting voltages VI to VI will be described.

1 m

The For example, when a plurality of R-color gamma correction data are input to the gamma correction circuit 5a in synchronization with the horizontal synchronization signal HS, the R-color gamma correction setting voltages VI to VI corresponding to the gamma correction data are output. You. Corrected by the gamma correction setting voltage VI to VI The R image voltage Vo is output from the source driver 6 to the display panel 7 as an applied voltage. What is important here is that, at this time, the gate line to which the R-color display element is connected in the display panel 7 is selected. That is, the R color image voltage corrected by the R color gamma correction setting voltages VI to VI corresponding to the R color gamma correction data input to the gamma correction circuit 5a is applied to the R color display element. You. And the next water

1 m

A plurality of G-color gamma correction data is input to the gamma correction circuit 5a in synchronization with the plane synchronization signal HS, and corrected by the corresponding G-color gamma correction setting voltages VI to VI.

1 m

The G color image voltage is applied to the G color display element. The same operation is performed for the B color, and these operations are repeated for each of the RGB colors. As described above, gamma correction is performed for each of the RGB colors, and while the display on the display panel 7 is checked in real time, the gamma correction data value of the external force is changed, and the gamma correction setting voltage VI Or VI

1 m adjustment is made to be appropriate.

When the adjustment is completed, the gamma correction data in the adjustment completed state is stored in the nonvolatile memory 9, and thereafter, the gamma correction data stored in the nonvolatile memory 9 is used. Here, the gamma correction data stored in the nonvolatile memory 9 corresponds to the gamma characteristics of each of the RGB colors. The storage of the gamma correction data in the nonvolatile memory 9 may be performed not only when the adjustment is completed but also every time new gamma correction data is input from an external force.

[0027] After adjusting the gamma correction setting voltages VI to VI for each of the RGB colors,

1 m

In this case, the gamma correction data stored in the non-volatile memory 9 is taken out for each of the RGB colors in order by the horizontal synchronization signal HS. Then, for example, when receiving the horizontal synchronization signal HS and extracting the R color gamma correction data, the data is output to the registers 12 to 12, and the DZA conversion is performed.

1 m

^ 13 to 13 convert to analog voltage, and R color via

1 m 1 m

Are output as the gamma correction setting voltages VI to VI of. The gamma correction setting voltage VI

The R-color image voltage Vo corrected by 1 m 1 to VI is output from the source driver 6 to the display panel 7 as an applied voltage. At this time, the R-color display element The connected gate line is selected. Same for G and B colors The same operation is performed, and these operations are repeated for each of the RGB colors. That is, the gamma correction circuit 5a sequentially outputs the gamma correction setting voltages VI to VI for each of the RGB colors by the horizontal synchronization signal HS, and the display panel 7 is connected to the display element of that color.

1 m

The selected gate line is selected. As described above, gamma correction is appropriately performed for each of the RGB colors.

As described above, the gamma correction circuit 5a can perform gamma correction for each of the RGB colors, and thus can adjust the color balance of the display panel. The display panel 7 is configured such that a plurality of display elements having one color strength are connected to each gate line, and a gate line to which a plurality of display elements of each color are sequentially connected is selected by a horizontal synchronization signal HS. Since the gamma correction circuit 5a performs gamma correction for each of the RGB colors, the color balance can be adjusted. Then, the liquid crystal display device 1 including the gamma correction circuit 5a and the display panel 7 can display a good image without shifting to a specific color.

Next, a liquid crystal display device 2 according to another preferred embodiment of the present invention will be described with reference to FIG. This liquid crystal display device 2 is an improvement of the above-described liquid crystal display device 1 in view of reducing current consumption. The liquid crystal display device 2 includes a source driver 6, a display panel 7, a gate driver 8, and a nonvolatile memory 9 having substantially the same circuit configuration or the same structure as the liquid crystal display device 1, and performs gamma correction. A gamma correction circuit 5b having a different configuration from that of the circuit 5a is included instead of the circuit 5a. The gamma correction circuit 5b includes a gamma correction data output circuit l ib and three sets of m registers 12 R to 12 R and 12 G to 12 G provided for each color of RGB.

1 ml m

, 12 B to 12 B, and any one of them is switched and selected, and a DZA converter 13

Selectors 17 to 17 that output to 1 m 1 to 13 and the selector 17 m 1 m in order by the horizontal synchronization signal HS

, A selector control circuit 18 for performing switching control of DZA converters 13 to 13,

1 m 1 m buffer 14 to 14.

1 m

The gamma correction circuit 5b extracts all gamma correction data for each color of RGB from the non-volatile memory 9 when the power is turned on, and stores them in three sets of registers 12R to 12R, 12R.

1 ml

G to 12G and 12B to 12B. This RGB color is kept for each color

m l m

The data is sequentially selected by the horizontal synchronization signal HS and enters the DZA converters 13 to 13. Is converted to an analog voltage, and the gamma correction setting current is supplied via the buffers 14 to 14.

1 m

Output as pressures VI through VI. As described above, this liquid crystal display device 2

1 m

In the display device 1, the gamma correction data stored in the nonvolatile memory 9 is taken out, that is, the access to the nonvolatile memory 9 is performed for each horizontal synchronization signal HS, whereas the access to the nonvolatile memory 9 is turned on. Only at the time, the number of times can be greatly reduced and the current consumption can be suppressed.

Next, a liquid crystal display device 3 according to still another preferred embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 3 includes a source driver 6, a display panel 7, a gate driver 8, and a non-volatile memory 9, which have substantially the same circuit configuration or structure as the liquid crystal display devices 1 and 2 described above. In place of the gamma correction circuit 5a or 5b, a gamma correction circuit 5c having a different configuration from them is included. The gamma correction circuit 5c includes a gamma correction data output circuit l ib and three sets of m registers 12 R to 12 R, 12 R,

1 ml

G to 12G, 12B to 12B, and three sets of m DZA transforms directly connected to them.

m l m

Switch 13R to 13R, 13G to 13G, 13B to 13B and any one of them

1 m l m l m

Selectors 17 to 17 for selecting and outputting to buffers 14 to 14 to be described later.

1 m 1 m

Selector control circuit 18 that controls switching of selectors 17 to 17 in order by the

1 m

And Knoffers 14 to 14.

1 m

[0032] The gamma correction circuit 5c extracts all gamma correction data for each color of RGB from the nonvolatile memory 9 when the power is turned on, and stores them in three sets of registers 12R to 12R, 12R.

1 ml

G to 12 G, 12 B to 12 B, and D / A converters 13 R to 13 R, 13 G

m l m 1 m l to 13 G, 13 B to 13 B, convert to analog voltage for each color of RGB and m l m

The The analog voltages for each of the RGB colors are sequentially selected by the horizontal synchronization signal HS, input to the buffers 14 to 14, and output as gamma correction setting voltages VI to VI.

1 m 1 m is applied. Therefore, the gamma correction circuit 5c can suppress the current consumption of the liquid crystal display device 3 and can switch the gamma correction setting voltage VI to VI at high speed because the voltage has already been converted to an analog voltage. Therefore, it is suitable for a display panel 7 having a high horizontal line frequency and requiring high-speed processing.

In the above gamma correction circuits 5a, 5b, and 5c, the D / A conversion ^ (DAC) If the current output capability is sufficient, the buffers 14 to 14 can be omitted.

1 m

In addition, the present invention is not limited to the above-described embodiment, and various design changes can be made within the scope of the claims. For example, in the present embodiment, the liquid crystal display device has been described. However, the gamma correction circuit, the display panel, and the display device of the present invention are not limited thereto, and a display device requiring gamma correction (for example, an organic EL display device) It is possible to apply to

Claims

The scope of the claims

[1] A gamma correction circuit that outputs a gamma correction setting voltage to correct an image voltage according to a non-linear correlation between a voltage applied to a display element and luminance.

A gamma correction data output circuit that outputs a plurality of gamma correction data for each of the RGB colors,

A plurality of registers for inputting and holding a plurality of gamma correction data;

A plurality of DZA converters for converting data of a plurality of registers into analog voltages and outputting a gamma correction setting voltage,

A gamma correction circuit comprising:

[2] The gamma correction circuit according to claim 1,

The gamma correction circuit outputs the gamma correction setting voltage via a buffer.

[3] The gamma correction circuit according to claim 1 or 2,

The gamma correction data output circuit outputs multiple sets of gamma correction data that are input externally for each color of RGB when adjusting the gamma correction setting voltage, and outputs multiple sets of gamma correction data for each color of RGB after adjusting the gamma correction setting voltage. A gamma correction circuit for extracting data from nonvolatile memory and outputting the data.

[4] The gamma correction circuit according to any one of claims 1 to 3,

The gamma correction data output circuit outputs a plurality of gamma correction data for each of the RGB colors in order according to a horizontal synchronization signal of the display panel.

[5] The gamma correction circuit according to any one of claims 1 to 3,

The plurality of registers are provided for each of RGB colors, and data of the plurality of registers of each color are sequentially selected by a horizontal synchronization signal of a display panel and input to the DZA converter. Gamma correction circuit.

[6] The gamma correction circuit according to any one of claims 1 to 3,

The plurality of registers and the plurality of DZA conversions are provided for each color of RGB, and the gamma correction setting voltage of each color is sequentially selected by a horizontal synchronization signal of a display panel and output. Gamma correction circuit characterized by being applied.

[7] In the gamma correction circuit according to claim 5 or 6,

A gamma correction circuit, wherein the plurality of registers provided for each color of RGB hold gamma correction data extracted from a non-volatile memory for each color of RGB when power is turned on.

[8] A display panel in which a plurality of display elements are arranged two-dimensionally for each of the RGB colors, and an applied voltage of a source line is applied to a plurality of display elements connected to a selected gate line,

A display panel, characterized in that a plurality of display elements having one color power are connected to each gate line, and a gate line to which a plurality of display elements of each color are sequentially connected is selected by a horizontal synchronization signal.

[9] a gamma correction circuit according to any one of claims 1 to 7,

A source driver for inputting image data and selecting a corresponding gamma correction setting voltage or their interpolation voltage to output a corrected image voltage;

9. The display panel according to claim 8, wherein the gate line is driven by the gate driver, and the corrected image voltage of the source driver is input to the S source line.

A display device comprising:

[10] The display device according to claim 9,

A display device wherein a gamma correction circuit sequentially outputs a gamma correction setting voltage for each color of RGB according to a horizontal synchronization signal, and a display panel selects a gate line to which a display element of the color is connected.

[11] The display device according to claim 9 or 10,

The display device is a liquid crystal display device.