JP2009111868A - Display device and white balance control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a color temperature, through simple operation, without considerably getting out of a black body radiation line. <P>SOLUTION: On a setting screen 100 for color temperature control, a color temperature selection part 102 for selecting a plurality of preset color temperature settings and RGB gain setting parts 103-105 are displayed. A user can select a desired color temperature setting from the plurality of color temperature settings. In such a case, if a default control value is not changed by user control, on a display device, previously controlled RGB conversion table data are used to convert an input signal, herein the user can change default RGB control values by arbitrarily operating slide bars 103a, 104a, 105a displayed on the RGB gain setting parts 103-105. White balance is controlled in accordance with the RGB control values based on the RGB gains changed by user control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device and a white balance adjustment method, and more particularly, to a technique for easily and accurately adjusting white balance when displaying an image to be displayed on a display device at a target color temperature.

  For example, in a display device such as a PC monitor or a liquid crystal television, white balance is adjusted in the manufacturing process. Here, the color development of each RGB color is adjusted so that an appropriate white color is displayed on the display screen. For example, during the manufacturing process, an image having a predetermined gradation is displayed on the display screen of the display device, and the display screen is detected by a sensor to measure the coordinate values x and y on the CIE chromaticity diagram. Then, based on the measured coordinate values, adjustment is performed for each of RGB so that the coordinate values become a predetermined target value. The adjustment is performed by adjusting the gain and the cut-off value in the RGB conversion table that defines the output gradation value for the gradation of the input video signal.

  As an example, when the gradation of an image is 256 bits of 8 bits, a slightly dark gray (for example, 64 gradations) and a light gray (for example, 200 gradations) are displayed on the screen, and an offset is applied to the dark gray gradation. Adjust and adjust the gain value in light gray tones. Thereby, the white balance of the display device is adjusted, and the adjustment value is stored.

In addition, there is a configuration in which such white balance adjustment is opened to the user so that the user can further change the white balance setting value set in advance in the manufacturing process.
FIG. 7 is a diagram for explaining a conventional white balance adjustment that can be adjusted by the user, and shows an example of a user interface screen displayed on the screen of the display device. In this example, a user interface for adjusting each gain and offset of RGB is displayed, and the user can arbitrarily adjust the gain and offset of RGB by using an operation input device such as a remote controller. It has become.

  In many PC monitors, liquid crystal televisions, and the like, the user can select a white color temperature. For example, in a liquid crystal television, a plurality of standard color temperature settings are prepared in advance, and the user can arbitrarily select these color temperatures. In many display devices such as a PC monitor, in addition to the selection of a plurality of standard color temperatures as described above, the user can adjust the color temperature.

  FIG. 8 shows an example of a screen of a user interface of the display device that can set an arbitrary color temperature from a plurality of color temperatures prepared in advance. In this example, red (R) and blue (B) gain adjustment is possible, and the color temperature of the display screen can be set. Here, it is possible to set the color temperature in about five steps discretely around 7500K. As a result, for example, the user selects an arbitrary color temperature from among the color temperatures prepared in advance between white with a bluish color (color temperature → high) and white with a bluish color (color temperature → low). It can be done.

With regard to such white balance adjustment technology by a user, for example, Patent Document 1 discloses a function that allows a user to select a desired color temperature by moving a cursor while viewing a color sample by displaying a color sample on a screen. Is disclosed. Here, the image display device of Patent Document 1 includes a display unit that displays a color sample on a screen, a moving unit that moves a cursor in response to an input from the user, and a determination input from the user. Adjusting means for adjusting RGB gain in accordance with the position of the cursor.
Japanese Patent Laid-Open No. 2001-177846

  As described above, in some display devices such as a PC monitor and a liquid crystal television, white balance adjustment is open to the user. However, the adjustment that is open to the user simply adjusts the RGB gain (and offset), and in the situation where there is no knowledge or measuring instrument for adjustment, the final white point after adjustment is the color. There arises a problem that the black body radiation line of the degree table easily deviates and adjustment becomes difficult.

For example, even if the white balance is adjusted by adjusting the RGB gain (and offset) at a specific color temperature setting, if the color temperature setting is changed, the balance is lost and the color temperature for each gradation is shifted. There is a problem that a desired color temperature cannot be obtained at each gradation. For example, an undesired phenomenon such as a greenish white at a low gradation and a reddish white at a high gradation occurs.
In this case, as the user's adjustment range for a specific color temperature setting increases, the white point tends to deviate greatly from the black body radiation line, and the color temperature shift for each gradation increases in other color temperature settings. As a result, the quality of image quality is significantly reduced. In other words, in the conventional white balance setting by RGB, when the color temperature setting is changed, an unexpected RGB adjustment value is applied, resulting in an unexpected image quality.

  In the technique of Patent Document 1, usability is improved by using an intuitive display method called a color sample, but a function that can be finely adjusted by a user based on a plurality of typical color temperature settings is disclosed and suggested. It has not been.

  The present invention has been made in view of the above circumstances, and allows a user to change a color temperature by using a plurality of color temperature settings prepared in advance, so that a black body radiation line can be easily operated. It is an object of the present invention to provide a display device and a white balance adjustment method capable of adjusting a color temperature without greatly deviating.

  In order to solve the above problems, the first technical means stores an adjustment value used for adjusting the white balance in each of a plurality of predetermined color temperature settings, and stored in the storage means. And a white balance adjustment means for adjusting the white balance using the adjustment value, and a display device capable of adjusting the white balance for each of a plurality of predetermined color temperature settings. The adjustment value changing means for changing the adjustment value being changed, and when the adjustment value is changed by the adjustment value changing means, the white balance adjustment means has changed the color temperature setting for which the adjustment value has been changed. The white balance is adjusted using the adjustment value.

  According to a second technical means, in the first technical means, a means for displaying a plurality of predetermined color temperature settings on the display device, and a color temperature setting to be set on the display device from the displayed plurality of color temperature settings. A means for receiving an instruction input for selecting a color, a means for displaying on the display device a screen for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting, and corresponding to the selected color temperature setting Means for receiving an instruction input for changing the setting of the adjustment value to be adjusted, and the adjustment value changing means changes the adjustment value stored for each color temperature setting in accordance with the instruction input for changing the adjustment value. It is what.

  According to a third technical means, in the first technical means or the second technical means, the adjustment value is conversion table data in which the gradation of the output video signal relative to the gradation of the input video signal is determined for each of RGB. Is.

  According to a fourth technical means, in the third technical means, the adjustment value is changed by adjusting the gain of the conversion table data.

  According to a fifth technical means, in the fourth technical means, the adjustment value is changed by multiplying a conversion function for converting an input value of the video signal into an output value by a coefficient. .

  The sixth technical means stores adjustment values used for adjusting the white balance for each of a plurality of predetermined color temperature settings, and uses the stored adjustment values to determine a plurality of predetermined color temperature settings. A white balance adjustment method in which a white balance can be adjusted for each display, wherein a display device includes a step of displaying a plurality of predetermined color temperature settings on a display screen of the display device and the displayed plurality of color temperature settings. A step of receiving an instruction input for selecting a color temperature setting to be set, a step of causing a display device to display a screen for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting, Receiving an instruction input for changing the setting of the adjustment value corresponding to the set color temperature, and storing for each color temperature setting according to the instruction input for changing the adjustment value. And changing the that adjustment value is obtained by further comprising a.

According to the present invention, the user can change the color temperature using a plurality of color temperature settings prepared in advance, so that the color temperature can be adjusted by a simple operation without greatly deviating from the black radiation line. Display device and white balance adjustment method can be provided.
In particular, according to the present invention, an adjustment range along the black body radiation line can be realized, and a desired color temperature can be obtained safely. Furthermore, according to the present invention, it is possible to perform the adjustment with a small adjustment amount by performing the user adjustment based on the color temperature setting prepared in advance, and the adjustment can be performed in a short time. Here, it is possible to make an adjustment to further change the color temperature while maintaining the white balance adjustment value unique to the liquid crystal module.

  Further, according to the present invention, the user only performs an operation of selecting a desired color temperature setting from the color temperature settings prepared in advance and an operation of changing each RGB color gain based on the selected color temperature setting. In the display device, the adjustment UI (user interface) can be simplified.

FIG. 1 is a block diagram for explaining a configuration example of an embodiment of a display device according to the present invention, and shows an example in which the display device of the present invention is applied to a liquid crystal television.
The AV selector 13 of the display device 1 receives a broadcast video signal received by the antenna 10 and selected and demodulated by the tuner unit 11 or an external input signal from an external device or the like to the external input terminal 12. The output signal is selected by.
The separation unit 14 separates the signal output from the AV selector 13 into a video signal, a data signal, an audio signal, and the like. The decoder unit 15 performs a decoding process on the separated signal. The data signal includes EPG (electronic program guide) program information, a code signal for OSD (on screen display) display, and the like.

The audio signal decoded by the decoder unit 15 is subjected to audio processing by the audio processing unit 16 and output from the speaker 17 as audio.
The video signal and data signal decoded by the decoder unit 15 are input to the video processor 18. The video processor 18 includes a video signal processing unit 181 and a white balance adjustment unit 182. The video signal processing unit 181 executes ADC (A / D conversion processing), YC separation processing, IP conversion processing, matrix conversion processing, or other video processing as necessary, and outputs RGB signals.

  The white balance adjustment unit 182 receives the RGB signals of the video output from the video signal processing unit 181 and adjusts the white balance. Here, gamma correction processing is also executed. In the display device 1, a plurality of color temperature settings are prepared in advance, and the white balance is adjusted in advance for each color temperature setting. The white balance adjustment value in each of the plurality of color temperature settings is set in the production process of the display device 1 and is held in the nonvolatile memory 19 such as an EEPROM. As the adjustment value, RGB conversion table data that defines the output gradation for the input gradation of the video signal for each of RGB is used.

  The RGB conversion table data held in the nonvolatile memory 19 is used for setting an output value in the white balance adjustment unit 182 of the video processor 18. Here, when the user selects an arbitrary color temperature setting from among a plurality of color temperature settings prepared in the display device 1, conversion table data for each color of RGB set in advance according to the color temperature setting is used, and the conversion is performed. The video signal is converted according to the table data, and the video signal is output with the converted output value.

  In the display device 1, any one of a plurality of color temperature settings can be selected by the user, and when any one of the plurality of color temperature settings is selected, RGB set for the color temperature setting is selected. For the conversion table data, the user can adjust the RGB gain for each of RGB. While confirming the adjustment UI displayed on the liquid crystal module 20 of the display device 1, the user performs adjustment by arbitrarily changing the RGB gain using an operation input unit such as a remote controller (not shown).

  The RGB conversion table data whose RGB gain has been adjusted by the user is newly stored in the non-volatile memory 19, and the white balance adjustment unit 182 of the video processor 18 performs the RGB conversion conversion to adjust the white balance at the color temperature setting value. Use table data. Also, when the gamma adjustment is performed by the user, the RGB output values are adjusted at the same ratio using the EGB conversion table data to adjust the RGB output values.

  The display device 1 includes a liquid crystal module 20 as display means. The liquid crystal module 20 includes a display device using a liquid crystal panel and a backlight. The liquid crystal panel displays an image by driving the liquid crystal according to the image signal whose output value has been adjusted by the white balance adjustment unit 182. The backlight includes a drive circuit and a light emitter, and the light emitter is driven by the drive circuit. As the illuminant, a general cold cathode tube (CCFL) or LED, or a hybrid type using both a cold cathode tube and an LED is applied.

  In the above configuration, the storage means of the present invention for storing the adjustment value used for adjusting the white balance for each of a plurality of predetermined color temperature settings corresponds to the nonvolatile memory 19 of FIG. The white balance adjusting means of the present invention corresponds to the white balance adjusting unit 182 of FIG. The adjustment value changing means of the present invention for changing the adjustment value stored for each color temperature setting is realized by a control unit such as a microcomputer (not shown) that controls each element such as the video processor 18.

  Similarly, according to the present invention, means for displaying the color temperature setting on the display screen of the display device, means for receiving an instruction input for selecting the color temperature setting to be set for the display device from the displayed plurality of color temperature settings, are selected. Means for displaying on the display device a screen for changing the adjustment value for the adjustment value corresponding to the selected color temperature setting, and means for receiving an instruction input for changing the setting of the adjustment value corresponding to the selected color temperature setting And the like are realized by a control unit such as a microcomputer. The operation input by the user to the control unit can be realized by a remote controller (not shown), an operation input button provided on the display device, or the like.

Next, the white balance adjustment applied to the embodiment of the present invention will be further described.
The liquid crystal panel included in the liquid crystal module 20 has a characteristic that the white chromaticity changes depending on the input gradation. For example, when an input signal of (R, G, B) = (128, 128, 128) is input, white emitted from the liquid crystal panel and an input signal of (R, G, B) = (255, 255, 255) The white that the LCD panel emits when is entered is not the same color.

Therefore, the difference is compensated, and adjustment is performed so that the white chromaticity (white point) is the same in all gradations of the input signal (white balance adjustment). In the embodiment according to the present invention, as described above, a plurality of color temperature settings are prepared in advance, and the white balance is adjusted in advance for each color temperature setting. The plurality of color temperature settings are set in five stages, for example, “high”, “high-medium”, “medium”, “medium-low”, and “low”.
Here, the most ideal white balance is realized, for example, by setting adjustment values as shown in FIG. 2 for the RGB values of the input signal.

As described above, in the embodiment according to the present invention, the adjustment for changing the RGB gain is released to the user for each of a plurality of color temperature settings preset in the display device 1.
Here, in order to prevent the preset light balance from being lost for each color temperature setting, a process of multiplying the RGB conversion function by a coefficient (which becomes a gain) is performed.
The general formula of conversion is given by the following formula when RGB conversion functions are f_R (input), f_G (input), and f_B (input), respectively, and RGB gains are g_R, g_G, and g_B, respectively.
Ouput (G) = g_R x f_R (Input)
Ouput (R) = g_G x f_G (Input)
Ouput (B) = g_B x f_B (Input)

  FIG. 3 is a diagram illustrating an example when the RGB conversion table data is multiplied by a coefficient. In this example, the conversion function of the RGB conversion table data shown in FIG. 3A is multiplied by a coefficient based on user settings. Here, it is assumed that the coefficients based on the user settings are g_R = 0.8, g_G = 1.1, and g_B = 0.8. In this case, the RGB conversion table data after the conversion function is multiplied by the coefficient is as shown in FIG. In the display device 1, the RGB conversion table data is stored in the nonvolatile memory 19 and used for white balance adjustment processing in the white balance adjustment unit 182.

  FIG. 4 is a chromaticity diagram for explaining the color temperature setting and the adjustment range thereof in the embodiment of the display device according to the present invention. In FIG. 4, P1 to P5 indicate a plurality of color temperature setting points set in the display device 1 of the present embodiment. In this example, the preset color temperature setting values are 5 points of 12000K (P1), 10500K (P2), 9300K (P3), 8000K (P4), and 6500K (P5). The point of 6500K corresponds to sRGB (standard RGB). In FIG. 4, S1 to S5 are color temperature adjustment ranges open to the user corresponding to the color temperature settings P1 to P5, respectively, and T is a color temperature adjustment range open to the user in the prior art. is there.

  As shown in FIG. 4, in the example of the prior art, since simple RGB gain adjustment is released to the user in a wide range, the range (adjustment range) T that can be adjusted by the user is large and has been adjusted by the user. There is a risk that the color temperature may deviate significantly from the blackbody radiation line. In this case, the larger the user's adjustment range at a specific color temperature setting, the more easily the adjusted white point deviates from the black body radiation line, and an unexpected RGB adjustment value when changing to another color temperature setting Has been applied, resulting in unexpected image quality.

  In the embodiment according to the present invention, the white point on the chromaticity diagram does not deviate greatly from the black body radiation line by appropriately setting the RGB gain adjustment ranges S1 to S5 that are released to the user. As described above, in this embodiment, the user performs adjustment to change the RGB gain with respect to the RGB adjustment values at a plurality of predetermined color temperature settings, and at this time, a constant based on the initial values at the color temperature settings is performed. Open the range as a user adjustable range. For this reason, the adjustment value by the user is not greatly deviated from the black body radiation line, and it is possible to prevent the RGB adjustment value from being greatly disturbed. Since the adjustment range along the black body radiation line can be realized, a desired color temperature can be obtained safely. Here, the white balance in the original color temperature setting can be prevented from being greatly reduced, and the deviation of the white point due to gradation can be suppressed. Furthermore, according to the present embodiment, since user adjustment is performed based on a color temperature setting prepared in advance, user adjustment can be performed in a short time.

FIG. 5 is a diagram showing an example of a user interface screen for color temperature adjustment in the display device according to the present invention.
In the display device 1, a color temperature adjustment setting screen 100 as shown in FIG. 5 can be displayed as a user interface screen according to the menu selection by the user. Here, from among the selection items displayed on the setting screen 100, when the “color temperature” 101 is selected by the user's operation, a color temperature selection unit that allows selection of a plurality of preset color temperature settings. 102 and RGB gain setting sections 103 to 105 are displayed.

  The color temperature selection unit 102 shows five predetermined color temperature settings. Here, five levels of “high”, “high-medium”, “medium”, “medium-low”, and “low” are set as the color temperatures of five points. These color temperature setting values correspond to the above 12000K (P1), 10500K (P2), 9300K (P3), 8000K (P4), and 6500K (P5).

  The user can select a desired color temperature setting from among these five color temperature settings using an operation input means such as a remote controller. For example, it is assumed here that “high-medium” is selected. In this case, if the default adjustment value is not changed by the user adjustment, the white balance adjustment unit 182 of the display device 1 uses the “high-medium” color temperature setting, that is, the RGB conversion table data adjusted in advance to 10500K. Is used to convert the input signal.

Here, the user can arbitrarily operate the slide bars 103a, 104a, and 105a displayed in the RGB gain setting sections 103 to 105 to change the default RGB gain. In this example, an adjustment range set in advance for the default RGB gain is represented by an index of +30 to −30, and the user moves the slide bars 103a, 104a, and 105a within the adjustment range, and an arbitrary index value is obtained. Is selected, the coefficient for multiplying the conversion function of the RGB conversion table data is determined based on the selected value. In this case, if the setting value of the RGB gain setting units 103 to 105 is “0”, the default RGB gain in the color temperature setting is used.
The RGB conversion table data based on the RGB gain changed by the user adjustment is held in the nonvolatile memory 19 and used for white balance adjustment in the white balance adjustment unit 182.

  The process as described above can be executed for each of the five color temperature settings displayed in the color temperature selection unit 102 of FIG. For example, when the user selects another color temperature using the color temperature selection unit 102, the white balance adjustment unit 182 of the display device 1 uses RGB conversion table data set in advance corresponding to the selected color temperature setting. Use to adjust the white balance. When the RGB gain is changed by the RGB gain setting units 103 to 105, the RGB conversion table data based on the changed RGB gain is held in the nonvolatile memory 19 and the white balance adjustment unit 182 adjusts the white balance. Used for.

  The embodiment of the white balance adjustment method of the embodiment according to the present invention stores an adjustment value used for adjusting the white balance for each of a plurality of predetermined color temperature settings, and uses the stored adjustment value. The white balance can be adjusted for each of a plurality of predetermined color temperature settings. Here, a step of displaying a plurality of predetermined color temperature settings on the display screen of the display device, and a step of receiving an instruction input for selecting a color temperature setting to be set for the display device from the displayed plurality of color temperature settings And a step of causing the display device to display a screen for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting, and changing the setting of the adjustment value corresponding to the selected color temperature setting. Receiving an instruction input; and changing an adjustment value stored for each color temperature setting in accordance with an instruction input for changing the adjustment value.

FIG. 6 is a flowchart for explaining an example of the white balance adjustment processing according to the present invention. Here, an example of the processing will be described using the display device 1 of FIG. 1 as an example.
First, the display device 1 displays a menu screen for color temperature adjustment in accordance with a menu display request or the like by a user operation (step S1). This menu screen is a higher-level menu screen before entering the setting screen 100 of FIG.

Then, a video adjustment item is selected by a user operation (step S2), and a professional setting item is further selected (step S3). Then, a color temperature item is selected from the professional setting items (step S4).
In this example, setting items such as “video adjustment”, “audio adjustment”, “energy saving setting”, “main unit setting”, and the like can be selected on the menu screen in step S1, and when “video adjustment” is selected here, In addition to the adjustment items such as “Brightness”, “Black Level”, “Color Saturation”, “Hue” of the image, a menu that allows the selection of “Pro Settings” is displayed. “Pro setting” is an item for setting the image more finely. When “Pro Settings” is selected, for example, a setting screen 100 as shown in FIG. 5 is displayed. Here, by selecting “color temperature”, a plurality of predetermined color temperature settings are displayed.

  As described above, in this example, the target color temperature can be adjusted by performing the operations of Step S1 to Step S4. Of course, such a menu setting is only an example, and in the embodiment according to the present invention. It is only necessary that the screen that enables selection of the color temperature setting and the adjustment value change setting at this time can be opened in accordance with the user operation.

  When the color temperature item is selected in step S4, the user next performs an operation of selecting a color temperature setting closest to the desired color temperature from among a plurality of color temperature settings previously set in the display device 1. (Step S5). Here, the display device 1 accepts an instruction input for selecting a color temperature setting. The selection of the color temperature setting is, for example, from among the five color temperature settings of “high”, “high-medium”, “medium”, “medium-low”, and “low” as shown in FIG. Refers to selecting the desired color temperature setting.

Then, the user adjusts the RGB gain with the slide bar for the selected color temperature setting (step S6). Here, the display device 1 displays a screen displaying a slide bar for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting, and instructs to change the setting of the adjustment value using the slide bar. Accept input.
As a result, the user can further arbitrarily change the RGB adjustment values set in advance for the selected color temperature setting, and adjust the color temperature to a desired color temperature.

It is a block diagram for demonstrating the structural example of one Embodiment of the display apparatus which concerns on this invention. It is a figure which shows an example of RGB conversion table data. It is a figure which shows an example when a coefficient is multiplied to RGB conversion table data. It is a chromaticity diagram for demonstrating the color temperature setting and its adjustment range in embodiment of the display apparatus which concerns on this invention. It is a figure which shows an example of the user interface screen for color temperature adjustment in the display apparatus which concerns on this invention. It is a flowchart for demonstrating an example of the white balance adjustment process which concerns on this invention. It is a figure for demonstrating the conventional white balance adjustment which can be adjusted by a user, and shows an example of the screen of the user interface displayed on the screen of a display apparatus. An example of a screen of a user interface of a display device that allows an arbitrary color temperature to be set from a plurality of color temperatures prepared in advance is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 10 ... Antenna, 11 ... Tuner part, 12 ... External input terminal, 13 ... AV selector, 14 ... Separation part, 15 ... Decoder part, 16 ... Sound processing part, 17 ... Speaker, 18 ... Video processor, DESCRIPTION OF SYMBOLS 19 ... Nonvolatile memory, 20 ... Liquid crystal module, 100 ... Setting screen, 101 ... Color temperature, 102 ... Color temperature selection part, 103 ... Setting part, 103a, 104a, 105a ... Slide bar, 181 ... Video signal processing part, 182 ... white balance adjustment section.

Claims (6)

Storage means for storing adjustment values used for adjusting white balance for each of a plurality of predetermined color temperature settings, and white balance for adjusting white balance using the adjustment values stored in the storage means And a display device that is capable of adjusting white balance for each of the plurality of predetermined color temperature settings,
Adjustment value changing means for changing the adjustment value stored for each color temperature setting, and when the adjustment value is changed by the adjustment value changing means, the white balance adjustment means changes the adjustment value. For the set color temperature, a white balance is adjusted using the changed adjustment value. The display device according to claim 1, wherein the display device displays the plurality of predetermined color temperature settings;
Means for receiving an instruction input for selecting a color temperature setting to be set in the display device from among the plurality of displayed color temperature settings;
Means for causing the display device to display a screen for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting;
Means for receiving an instruction input for changing the setting of the adjustment value corresponding to the selected color temperature setting;
The display device according to claim 1, wherein the adjustment value changing unit changes the adjustment value stored for each color temperature setting in accordance with an instruction input for changing the adjustment value.   3. The display device according to claim 1, wherein the adjustment value is conversion table data in which the gradation of the output video signal with respect to the gradation of the input video signal is determined for each of RGB.   4. The display device according to claim 3, wherein the adjustment value is changed by adjusting a gain of the conversion table data.   5. The display device according to claim 4, wherein the adjustment value is changed by multiplying a conversion function for converting an input value of a video signal into an output value by a coefficient. The adjustment value used for adjusting the white balance is stored for each of a plurality of predetermined color temperature settings, and the stored adjustment value is used to adjust the white balance for each of the plurality of predetermined color temperature settings. A white balance adjustment method that can be adjusted,
Displaying the predetermined plurality of color temperature settings on a display screen of a display device;
Receiving an instruction input for selecting a color temperature setting to be set in the display device from the displayed plurality of color temperature settings;
Displaying, on the display device, a screen for changing the setting of the adjustment value for the adjustment value corresponding to the selected color temperature setting;
Receiving an instruction input for changing the setting of the adjustment value corresponding to the selected color temperature setting;
Changing the stored adjustment value for each of the color temperature settings in accordance with an instruction input for changing the adjustment value.

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