JP2005269110A - Gamma correction circuit, display panel, and display device including them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of adjusting a color balance of a display panel.
A display device 1 includes a gamma correction data output circuit 11a for outputting a plurality of gamma correction data for each of RGB colors, and a plurality of registers 12 _{1 to} 12 _m for inputting and holding a plurality of gamma correction data. And a plurality of D / A converters (DACs) 13 _{1 to} 13 _m that convert the data of the plurality of registers 12 _{1 to} 12 _m into analog voltages and output the gamma correction setting voltages VI _{1 to} VI _m , respectively. A gamma correction circuit 5a, a source driver 6 that outputs a corrected image voltage by inputting image data and selecting a corresponding gamma correction setting voltage or an interpolation voltage thereof, and a gate driver 8 for one color. The gate line to which a plurality of display elements consisting of the above are connected is driven, and the corrected image voltage of the source driver 6 is the source And a display panel 7 that is input to the in-and.
[Selection] Figure 1

Description

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

Generally, a display panel of a display device such as a liquid crystal display device has a non-linear correlation, that is, a gamma characteristic, between a voltage applied to a display element and luminance. A solid curve A in FIG. 5 is a characteristic of the liquid crystal display element, that is, a gamma characteristic when the applied voltage is used as it is without correcting (gamma correction) the image voltage (for example, V ₁ or V _m ). 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, if the image voltage (for example, V ₁ or V _m ) is applied as it is without performing gamma correction, a good image cannot be displayed because it follows this nonlinear correlation. Therefore, in order to display a good image, the image voltage (for example, V ₁ or V _m ) is corrected by gamma correction so that the image voltage and the luminance are along a broken straight line B having a linear correlation. The applied image voltage (for example, VI ₁ or VI _m ) is used.

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. The applicant of the present application has proposed a gamma correction circuit based on those disclosed in these patent documents in Japanese Patent Application No. 2002-326266. FIG. 6 shows a liquid crystal display device having a gamma correction circuit similar to Japanese Patent Application No. 2002-326266. The liquid crystal display device 101 receives a gamma correction circuit 105 a that outputs gamma correction setting voltages VI _{1 to} VI _m and n-bit (for example, 8 bits) image data Di, and corresponding gamma correction setting voltages VI _{1 to} VI _1. By selecting VI _m or an interpolation voltage thereof described later, a source driver 6 that outputs the corrected image voltage Vo as an applied voltage to a display panel 107 described later for each source line, a display panel 107, and a display panel 107 And a non-volatile memory 109 for storing gamma correction data.

The gamma correction circuit 105a converts serial gamma correction data input from the outside via the input terminal SD into L-bit (for example, 10 bits) parallel gamma that is digital data corresponding to the gamma correction setting voltages VI _{1 to} VI _m. A gamma correction data output circuit 111a that converts and outputs the correction data, m registers (for example, nine registers) 12 _{1 to} 12 _m that receive and store the gamma correction data, and converts the data into an analog voltage. For example, 8-bit D / A converters (DACs) 13 _{1 to} 13 _m, and buffers 14 _{1 to} 14 _m for increasing the output current capability and outputting them as gamma correction setting voltages VI _{1 to} VI _m , It has. The gamma correction data output circuit 111a stores the gamma correction data in the nonvolatile memory 109 and retrieves it from the nonvolatile memory 109 as necessary.

The source driver 6 uniformly interpolates between each of the gamma correction setting voltages VI _{1 to} VI _m that are the output of the gamma correction circuit 105a, for example, between VI ₁ and VI ₂ with m ′ resistors, and generates an interpolation voltage. A resistor ladder 15 to be generated, and a decoder 16 that outputs a corrected image voltage Vo by selecting gamma correction setting voltages VI _{1 to} VI _m or their interpolation voltages in accordance with n-bit image data Di. . The display panel 107 to which the image voltage Vo is input has ²ⁿ gradations. That is, if n is 8, the gradation of the display panel 107 is 256. Further, the value of m ′ is obtained by 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 the voltage value of VI ₁ , and if the value of the image data Di is 16, the corrected image voltage Vo is the voltage at the center of VI ₁ and VI _2. Value.

The gamma correction setting voltages VI _{1 to} VI _m are made appropriate by confirming the display on the display panel 107 in real time and inputting serial gamma correction data from the outside to the gamma correction circuit 105a via the input terminal SD. Adjusted. When the adjustment is completed, the gamma correction data in the adjustment completed state is stored in the nonvolatile memory 109, and thereafter, the gamma correction data stored in the nonvolatile memory 109 is used.

Next, a liquid crystal display device having the same components as those of another embodiment of Japanese Patent Application No. 2002-326266 is shown in FIG. The liquid crystal display device 102 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 device 101 described above, and a gamma correction circuit. Instead of 105a, a gamma correction circuit 105b having a different configuration is provided. The gamma correction circuit 105b includes a gamma correction data output circuit 111b and two sets of m registers 12 ₁ a to 12 _m a and 12 ₁ b for data corresponding to odd / even numbers of a horizontal line to be described later. to 12 _m b and, either one of the selectors 117 ₁ to 117 _m to set the selected output to the later of the D / a converter 131 _to 13 _m, the horizontal scanning lines of the display panel 107 (horizontal line) And a selector control circuit 118 that performs switching control of the selectors 117 _{1 to} 117 _m according to the odd number / even number of the horizontal line, and the D / A converters 13 _{1 to} 13. _m and buffers 14 _{1 to} 14 _m . The gamma correction circuit 105b, in addition to the function of the gamma correction circuit 105a, since the gamma correction setting voltages VI ₁ to VI _m depending on the odd-numbered / even-numbered horizontal line can be varied at high speed, for example, the upper and lower horizontal This is suitable for a line inversion driving method for inverting the polarity of positive and negative lines.

Next, a liquid crystal display device having the same components as those of still another embodiment of Japanese Patent Application No. 2002-326266 is shown in FIG. 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 gamma correction. Instead of the circuits 105a and 105b, a gamma correction circuit 105c having a different configuration is provided. The gamma correction circuit 105c includes a gamma correction data output circuit 111b and two sets of m registers 12 ₁ a to 12 _m a and 12 ₁ b to 12 for data corresponding to the odd number / even number of the horizontal line. _m b and two sets of m D / A converters 13 ₁ a to 13 _m a, 13 ₁ b to 13 _m b directly connected to them, and one of these sets is selected to be described later comprises a selector 117 ₁ to 117 _m to be output to the buffer 14 ₁ to 14 _m, the selector control circuit 118 which performs switching control of the selector 117 ₁ to 117 _m by the horizontal synchronizing signal HS, the buffer 14 ₁ to 14 _m, a. Similar to the gamma correction circuit 105b, this gamma correction circuit 105c is suitable for, for example, a line inversion type driving method that inverts positive and negative polarities in the upper and lower horizontal lines. Since the gamma correction setting voltages VI _{1 to} VI _m can be changed according to the number, it is more suitable for the display panel 107 having a high horizontal line frequency.

Japanese Patent Laid-Open No. 10-108040 JP-A-11-32237 US Pat. No. 5,796,384

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 _{1 to} VI _m according to the individual display panels 107.

By the way, in recent years, color liquid crystal display devices have become widespread, and further enlargement of the display and higher quality have been demanded. As shown in FIG. 9A, the display panel of the color liquid crystal display device has a plurality of display elements arranged two-dimensionally for each of RGB colors, and R (red) and G (green) in the column direction. , B color (blue) in the order of stripes. FIG. 4B is a circuit diagram corresponding to the arrangement diagram of FIG. The display elements in one row are connected to one gate line Gi (or Gi _{+ 1} or the like) and are provided in the order of R color, G color, and B color. The display elements in one column are connected to one source line Sj (or Sj _{+ 1} or the like), and are composed of one color of RGB.

  In order to display a good image, the luminance balance, that is, the color balance is taken for each of the RGB colors so that the color is not shifted to a specific color. However, when a color balance is lost due to a characteristic shift of a backlight or a color filter when a display panel is manufactured, a phenomenon such as a slight shift to a specific color and, for example, the entire image becomes bluish. The inventor of the present application has also considered the progress of display enlargement, and has studied a means for relatively easily adjusting the color balance of the display panel to suppress the above phenomenon in order to further improve the image quality. Focused on improving the gamma correction circuit and display panel.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a gamma correction circuit capable of adjusting the color balance of the display panel, a display panel, and a display device including them. is there.

  In order to solve the above problems, a gamma correction circuit according to claim 1 is a gamma correction circuit that outputs a gamma correction setting voltage to correct an image voltage in accordance with a non-linear correlation between an applied voltage and luminance of a display element. A correction circuit for outputting a plurality of gamma correction data for each of RGB colors, a plurality of registers for inputting and holding a plurality of gamma correction data, and a plurality of registers for analog data And a plurality of D / A converters that convert the voltage to output a gamma correction set voltage.

  A gamma correction circuit according to a second aspect of the present invention is the gamma correction circuit according to the first aspect, wherein the gamma correction data output circuit receives a plurality of gamma correction data inputted from the outside for each color of RGB at the time of adjusting the gamma correction setting voltage. After the output and the gamma correction setting voltage adjustment, a plurality of gamma correction data for each color of RGB are extracted from the nonvolatile memory and output.

  A gamma correction circuit according to a third aspect is the gamma correction circuit according to the first or second aspect, wherein the gamma correction data output circuit sequentially includes a plurality of gamma correction data for each color of RGB in accordance with a horizontal synchronizing signal of the display panel. Is output.

  A gamma correction circuit according to a fourth aspect of the present invention is the gamma correction circuit according to the first or second aspect, wherein the plurality of registers are provided for each color of RGB, and the plurality of registers for each color are sequentially provided by a horizontal synchronization signal of a display panel. Is selected and input to the D / A converter.

  A gamma correction circuit according to a fifth aspect is the gamma correction circuit according to the first or second aspect, wherein the plurality of registers and the plurality of D / A converters are provided for each color of RGB, and a horizontal synchronization signal of a display panel Thus, the gamma correction setting voltage for each color is selected and output in order.

  The display panel according to claim 6 is a display panel in which a plurality of display elements are arranged two-dimensionally for each of RGB colors, and a source line applied voltage is applied to the plurality of display elements connected to the selected gate line. In addition, a plurality of display elements of one color 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.

  A display device according to claim 7 receives the gamma correction circuit according to any one of claims 1 to 5 and image data, and selects a corresponding gamma correction setting voltage or an interpolation voltage thereof, 7. A source driver that outputs a corrected image voltage; and a display panel according to claim 6, wherein the gate line is driven by the gate driver, and the corrected image voltage of the source driver is input to the source line. It is characterized by.

  The gamma correction circuit of the present invention is provided with a gamma correction data output circuit for outputting a plurality of gamma correction data for each color of RGB, so that it is used together with a display panel in which a plurality of display elements of one color are connected to the gate line. By doing so, it is possible to perform gamma correction for each color of RGB, thereby adjusting the color balance of the display panel. Further, in the display panel of the present invention, a plurality of display elements of one color 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 by the gamma correction circuit of the present invention. The display device of the present invention including the gamma correction circuit and the display panel can display a good image without shifting to a specific color.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of a liquid crystal display device 1 according to an embodiment of the present invention. The liquid crystal display device 1 includes a gamma correction circuit that outputs gamma correction setting voltages VI _{1 to} VI _m for correcting an image voltage in accordance with a non-linear correlation between an applied voltage and luminance of a liquid crystal display element. 5a and n-bit (for example, 8-bit) image data Di are input, and the corresponding gamma correction setting voltages VI _{1 to} VI _m or their interpolated voltages are selected to apply the corrected image voltage Vo to the applied voltage. The source driver 6 that outputs to the display panel 7 to be described later for each source line, the display panel 7 that has a color liquid crystal display element, the gate driver 8 that drives the gate line of the display panel 7, and the gamma correction data are stored. A non-volatile memory 9. 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 input terminal SD from the outside into L bits (for example, 10 bits) which are digital data corresponding to the gamma correction setting voltages VI _{1 to} VI _m. Bit) parallel gamma correction data and output the gamma correction data output circuit 11a, m (for example, 9) registers 12 _{1 to} 12 _m for inputting and holding the gamma correction data, and the data Are converted into analog voltages and output, for example, 8-bit D / A converters (DACs) 13 _{1 to} 13 _m, and a buffer 14 that increases the current capability of the output and outputs them as gamma correction setting voltages VI _{1 to} VI _{m 1 to} 14 _m . Further, the gamma correction data output circuit 11a, when adjusting the gamma correction setting voltages VI ₁ to VI _m, gamma correction data of the serial input sequentially for each color of RGB through the input terminal SD from the outside of the parallel gamma while outputs the converted correction data register ₁₂₁ to 12 _m, to store for each of the RGB color gamma correction data, i.e. R gamma correction data, G gamma correction data, and B gamma correction data in the nonvolatile memory 9. The gamma correction data output circuit 11a adjusts the gamma correction setting voltages VI _{1 to} VI _m and then sequentially stores the gamma corrections stored in the non-volatile memory 9 for each color of RGB in accordance with the horizontal synchronization signal HS of the display panel 7. Remove the data into the register 12 ₁ through 12 _m.

As shown in FIG. 2A, the display panel 7 has a plurality of display elements arranged in two dimensions for each of the RGB colors, and is arranged in a stripe shape in the order of R, G, and B in the row direction. Yes. FIG. 4B is a circuit diagram corresponding to the arrangement diagram of FIG. Each row, that is, each gate line Gi (or Gi _{+ 1,} etc.) is connected to a plurality of display elements made of one color of RGB. A plurality of display elements are connected in the order of R, G, and B to one column, that is, one source line Sj (or Sj _{+ 1} or the like). In the display panel 7, a gate line Gi (or Gi _{+ 1} or the like) to which a plurality of display elements of each color are connected in order by a horizontal synchronization signal HS is selected by a gate driver 8, and the selected gate line Gi (or Gi) is selected. applied voltage on the source line Sj (or Sj _{+ 1,} etc.) is applied to the plurality of display devices connected to _+1, etc.).

Next, the operation for adjusting the gamma correction setting voltages VI _{1 to} VI _m and the operation after the adjustment will be described. First, the case where the gamma correction setting voltages VI _{1 to} VI _m are adjusted will be described. For example, when a plurality of R color gamma correction data is input to the gamma correction circuit 5a in synchronization with the horizontal synchronization signal HS, R color gamma correction setting voltages VI _{1 to} VI _m corresponding to the gamma correction data are output. Is done. The R image voltage Vo corrected by the gamma correction setting voltages VI _{1 to} VI _m is output from the source driver 6 to the display panel 7 as an applied voltage. What is important here is that the gate line to which the display element of R color is connected in the display panel 7 is selected at this time. In other words, the R color image voltage corrected by the R color gamma correction setting voltages VI _{1 to} VI _m corresponding to the R color gamma correction data input to the gamma correction circuit 5a is applied to the R color display element. Is done. Then, a plurality of gamma correction data for G color in synchronization with the next horizontal synchronizing signal HS is input to the gamma correction circuit 5a, the G color corrected by the gamma correction setting G color corresponding voltage VI ₁ to VI _m Is applied to the G 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 color of RGB, and while the display on the display panel 7 is confirmed in real time, the gamma correction data value from the outside is changed, and the gamma correction setting voltages VI _{1 to} VI _m are appropriate. Adjustments are made to

  When the adjustment is completed, the gamma correction data in the adjustment completed state is stored in the non-volatile memory 9, and thereafter, the gamma correction data stored in the non-volatile memory 9 is used. Here, the gamma correction data stored in the non-volatile memory 9 corresponds to the gamma characteristic for each color of RGB. Note that the gamma correction data may be stored in the nonvolatile memory 9 not only when the adjustment is completed, but also whenever new gamma correction data is input from the outside.

After adjusting the gamma correction setting voltages VI _{1 to} VI _m for each of the RGB colors, the gamma correction data stored in the nonvolatile memory 9 is used. In this case, the gamma correction data stored in the nonvolatile memory 9 is extracted. Is performed for each color of RGB in turn by the horizontal synchronization signal HS. For example, when R-color gamma correction data is extracted in response to the horizontal synchronization signal HS, the data is output to the registers 12 _{1 to} 12 _m and converted to analog voltages by the D / A converters 13 _{1 to} 13 _m. The converted color is output as the R color gamma correction setting voltages VI _{1 to} VI _m via the buffers 14 _{1 to} 14 _m . The R color image voltage Vo corrected by the gamma correction setting voltages VI _{1 to} VI _m is output from the source driver 6 to the display panel 7 as an applied voltage. The gate line to which the color display element is connected is selected. Similar operations are performed for the G and B colors, and these operations are repeated for each of the RGB colors. As described above, gamma correction is appropriately performed for each color of RGB.

  In this way, the gamma correction circuit 5a can perform gamma correction for each of the RGB colors, and thereby adjust the color balance of the display panel. Further, in the display panel 7, a plurality of display elements of one color 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 the horizontal synchronization signal HS. Therefore, the color balance can be adjusted by performing gamma correction on each of the RGB colors by the gamma correction circuit 5a. 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 embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 2 is an improvement of the liquid crystal display device 1 from the viewpoint of suppressing 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 includes a gamma correction circuit 5a. Instead, a gamma correction circuit 5b having a different configuration is provided. The gamma correction circuit 5b includes a gamma correction data output circuit 11b and three sets of m registers 12 ₁ R to 12 _m R, 12 ₁ G to 12 _m G, and 12 ₁ B to 12 provided for each color of RGB. selectors 17 _{1 to} 17 _m for selecting _m B and any one of them and outputting them to D / A converters 13 _{1 to} 13 _m, which will be described later, and selectors 17 _{1 to} 17 _{m in} turn by the horizontal synchronization signal HS A selector control circuit 18 that performs switching control, D / A converters 13 _{1 to} 13 _m , and buffers 14 _{1 to} 14 _m are provided.

The gamma correction circuit 5b takes out all gamma correction data for each color of RGB from the nonvolatile memory 9 when the power is turned on, and extracts them from three sets of registers 12 ₁ R to 12 _m R, 12 ₁ G to 12 _m G, 12 Hold at ₁ B to 12 _mB . The data held for each color of RGB is sequentially selected by the horizontal synchronization signal HS, input to the D / A converters 13 _{1 to} 13 _m , converted into analog voltages, and passed through the buffers 14 _{1 to} 14 _m. Gamma correction setting voltages VI _{1 to} VI _m are output. As described above, in the liquid crystal display device 2, in the liquid crystal display device 1 described above, the gamma correction data stored in the nonvolatile memory 9 is extracted, that is, the nonvolatile memory 9 is accessed for each horizontal synchronization signal HS. On the other hand, the non-volatile memory 9 is accessed only when the power is turned on, and the number of times can be greatly reduced, thereby suppressing current consumption.

Next, a liquid crystal display device 3 which is still another 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 nonvolatile memory 9 having substantially the same circuit configuration or the same structure as the liquid crystal display devices 1 and 2. Instead of the gamma correction circuit 5a or 5b, a gamma correction circuit 5c having a different configuration is provided. The gamma correction circuit 5c includes a gamma correction data output circuit 11b and three sets of m registers 12 ₁ R to 12 _m R, 12 ₁ G to 12 _m G, and 12 ₁ B to 12 provided for each color of RGB. _m B and three sets of m D / A converters 13 ₁ R to 13 _m R, 13 ₁ G to 13 _m G, and 13 ₁ B to 13 _m B directly connected to them Selectors 17 _{1 to} 17 _m that select a set of the outputs and output to buffers 14 _{1 to} 14 _m, which will be described later, a selector control circuit 18 that performs switching control of the selectors 17 _{1 to} 17 _{m in} order by a horizontal synchronization signal HS, and a buffer 14 _{1 to} 14 _m .

The gamma correction circuit 5c takes out all gamma correction data for each color of RGB from the nonvolatile memory 9 when the power is turned on, and extracts them from three sets of registers 12 ₁ R to 12 _m R, 12 ₁ G to 12 _m G, 12 ₁ B to 12 _m B, and converted into analog voltages for each color of RGB by D / A converters 13 ₁ R to 13 _m R, 13 ₁ G to 13 _m G, 13 ₁ B to 13 _m B deep. The analog voltages for the respective RGB colors are sequentially selected by the horizontal synchronization signal HS, input to the buffers 14 _{1 to} 14 _m, and output as the gamma correction setting voltages VI _{1 to} VI _m . Thus, the gamma correction circuit 5c is configured to suppress current consumption of the liquid crystal display device 3, already since the converted analog voltage can be switched at high speed gamma correction setting voltages VI ₁ to VI _m. 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 buffers 14 _{1 to} 14 _m can be omitted if the current output capability of the D / A converter (DAC) is sufficient.

  Further, although the liquid crystal display device has been described in the present embodiment, the gamma correction circuit, the display panel, and the display device of the present invention are not limited to this, and are applied to a display device that requires gamma correction (for example, an organic EL display device). Is possible.

1 is a circuit diagram of a display device according to an embodiment of the present invention. The display panel same as the above is shown, (a) is an array diagram of RGB display elements. (B) is a circuit diagram corresponding to it. The circuit diagram of the display device concerning another embodiment of the present invention. The circuit diagram of the display apparatus concerning another embodiment of the present invention. Gamma characteristic diagram. The circuit diagram of the display apparatus of background art. The circuit diagram of another display apparatus of background art. The circuit diagram of another display apparatus of background art. The color display panel of background art is shown, (a) is an array diagram of RGB display elements. (B) is a circuit diagram corresponding to it.

Explanation of symbols

1, 2, 3 Liquid crystal display device (display device)
5a, 5b, 5c gamma correction circuit
6 Source driver
7 Display panel
8 Gate driver
9 Nonvolatile memory 11a, 11b Gamma correction data output circuit 12 _{1 to} 12 _m Register in the 12 gamma correction circuit 5a 12 ₁ R to 12 _m R R color register in the gamma correction circuits 5b and 5c 12 ₁ G to 12 _m G Gamma correction circuit 5b, G color register 12 ₁ B to ₁₂ m of the 5c B gamma correction circuit 5b, the register 13 ₁ through 13 of the B-color in 5c _m gamma correction circuit 5a, D / a converter 13 in 5b ₁ R to 13 _m R D / A converter 13 ₁ G to 13 _m G in the gamma correction circuit 5c G D / A converter 13 ₁ B to 13 _m B in the gamma correction circuit 5c / A converter

Claims (7)

A gamma correction circuit that outputs a gamma correction setting voltage to correct an image voltage according to a non-linear correlation between an applied voltage and luminance of a display element,
A gamma correction data output circuit for outputting a plurality of gamma correction data for each color of RGB,
A plurality of registers for inputting and holding a plurality of gamma correction data;
A plurality of D / A converters for converting data of a plurality of registers into analog voltages and outputting a gamma correction setting voltage;
A gamma correction circuit comprising: The gamma correction circuit according to claim 1,
The gamma correction data output circuit outputs a plurality of externally input gamma correction data for each of the RGB colors when adjusting the gamma correction setting voltage, and after adjusting the gamma correction setting voltage, the plurality of gamma correction data for each of the RGB colors is nonvolatile. Gamma correction circuit, wherein the gamma correction circuit is output from the memory. In the gamma correction circuit according to claim 1 or 2,
The gamma correction data output circuit outputs a plurality of gamma correction data for each color of RGB sequentially in accordance with a horizontal synchronizing signal of the display panel. In the gamma correction circuit according to claim 1 or 2,
A plurality of registers are provided for each color of RGB, and data of a plurality of registers of each color is selected in order by a horizontal synchronizing signal of a display panel and input to a D / A converter. In the gamma correction circuit according to claim 1 or 2,
The plurality of registers and the plurality of D / A converters are provided for each color of RGB, and a gamma correction setting voltage for each color is selected and output in order by a horizontal synchronization signal of the display panel. . A display panel in which a plurality of display elements are arranged two-dimensionally for each color of RGB and a source line applied voltage is applied to a plurality of display elements connected to a selected gate line,
A display panel, wherein a plurality of display elements of one color are connected to each gate line, and a gate line to which a plurality of display elements of each color are connected in order is selected by a horizontal synchronization signal. A gamma correction circuit according to any one of claims 1 to 5,
A source driver that inputs image data and outputs a corrected image voltage by selecting a corresponding gamma correction setting voltage or an interpolation voltage thereof; and
The display panel according to claim 6, wherein the gate line is driven by the gate driver, and the corrected image voltage of the source driver is input to the source line;
A display device comprising:

Images