WO2011043290A1 - 液晶表示装置 - Google Patents
液晶表示装置 Download PDFInfo
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- WO2011043290A1 WO2011043290A1 PCT/JP2010/067357 JP2010067357W WO2011043290A1 WO 2011043290 A1 WO2011043290 A1 WO 2011043290A1 JP 2010067357 W JP2010067357 W JP 2010067357W WO 2011043290 A1 WO2011043290 A1 WO 2011043290A1
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- temperature
- liquid crystal
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- display device
- gamma
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
- G09G3/3648—Control of matrices with row and column drivers using an active matrix
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0252—Improving the response speed
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/04—Maintaining the quality of display appearance
- G09G2320/041—Temperature compensation
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2340/00—Aspects of display data processing
- G09G2340/16—Determination of a pixel data signal depending on the signal applied in the previous frame
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
- G09G3/3426—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines the different display panel areas being distributed in two dimensions, e.g. matrix
Definitions
- the present invention relates to a liquid crystal display device, and more specifically, a liquid crystal having an overdrive function for improving the response speed of liquid crystal to a video signal and a function for adjusting gamma characteristics according to a temperature detected by a temperature sensor.
- the present invention relates to a display device.
- LCD Liquid Crystal Display
- CRT Cathode Ray Ray Tube
- TFT thin film transistor
- LCDs are widely used as display devices for television receivers, it is necessary to embody moving images, but until now, LCDs have a slow response speed and it is difficult to embody moving images. It was.
- the driving is higher than the gradation voltage for the input image signal of the current frame determined in advance according to the combination of the input image signal of the previous frame and the input image signal of the current frame.
- a liquid crystal drive (overdrive) system that supplies a voltage to a liquid crystal display panel is known.
- this driving method is referred to as overshoot driving.
- a temperature sensor is arranged in a place where the heat generation action by other members such as an inverter transformer and a power supply unit for lighting the backlight light source is hardly received, and the temperature of the liquid crystal display panel is detected as accurately as possible. I have to. Then, an appropriate enhancement conversion parameter corresponding to the detected temperature of the liquid crystal display panel is selected, whereby appropriate enhancement conversion data (write gradation data), that is, overshoot drive voltage (hereinafter referred to as OS drive voltage) is selected.
- OS drive voltage overshoot drive voltage
- Patent Document 1 discloses a temperature sensor that detects the temperature in the device and an installation mode detection unit that detects the installation mode of the device. Regardless of the installation form of the apparatus, appropriate enhancement conversion data can always be obtained and supplied to the liquid crystal display panel.
- a gamma that performs gamma correction on input digital image data in order to display an image more naturally or in a quality according to user's preference.
- a correction circuit is provided.
- appropriate conversion data set according to the gamma characteristic of the liquid crystal panel used is stored in advance in a lookup table (LUT) set in a ROM or the like. Yes.
- the gamma correction circuit performs gamma correction by reading conversion data corresponding to the gradation value of the input digital image data from the LUT.
- the response speed of the liquid crystal has a very large temperature dependency, and the gamma curve changes according to the change of the ambient temperature.
- the gate voltage supplied to the liquid crystal panel is adjusted according to the ambient temperature detected by a temperature sensor (such as a thermistor) so that the gamma curve change (gamma deviation) due to this temperature is corrected and the gamma curve is kept constant.
- a temperature sensor such as a thermistor
- the OS drive voltage is determined based on the correlation between the sensor temperature (ambient temperature) at the maximum brightness of the backlight and the panel surface temperature. Specifically, the correlation between the sensor temperature and the panel surface temperature can be indicated by a cubic approximate curve shown in FIG. When the sensor temperature changes, the OS drive voltage is changed following this.
- the panel surface temperature changes quickly, but the sensor temperature may not change immediately.
- the OS drive voltage since the panel surface temperature has changed, it is necessary to change the OS drive voltage.
- the OS drive voltage since the sensor temperature does not change, the OS drive voltage that follows this cannot be changed. That is, it is necessary to increase the OS drive voltage when the panel surface temperature is lowered, but the original OS drive voltage cannot be supplied to the liquid crystal panel, thereby reducing the response speed of the liquid crystal and degrading the image quality. There is a problem.
- the temperature sensor for measuring the ambient temperature is preferably provided in the liquid crystal display panel for its original purpose, but this is difficult because it hinders display. It is attached to other members such as a circuit board. For this reason, a temperature sensor is arranged in a place where the heat generation action by other members such as an inverter transformer and a power supply unit for lighting the backlight light source is hardly received, and the temperature of the liquid crystal display panel is detected as accurately as possible. I have to.
- the correlation between the sensor temperature and the panel surface temperature can be represented by a cubic approximate curve shown in FIG.
- the panel surface temperature changes quickly, but the sensor temperature may not change immediately.
- the gamma value is deviated from the set value (for example, 2.2) in accordance with the change in the panel surface temperature.
- the gamma shift is adjusted by changing the gate voltage according to the sensor temperature in the method described in Patent Document 2, the sensor temperature does not change even if the panel surface temperature changes as described above. In this case, the gamma shift cannot be adjusted.
- the present invention has been made in view of the above circumstances, and provides a liquid crystal display device capable of performing appropriate overshoot driving even when the panel surface temperature changes due to a change in the luminance of the backlight. Objective. It is another object of the present invention to provide a liquid crystal display device capable of performing appropriate gamma correction even when the panel surface temperature changes due to a change in the light emission luminance of the backlight.
- a first technical means of the present invention includes a liquid crystal panel that displays an input video signal, a light source that illuminates the liquid crystal panel, and a light source luminance control unit that controls the light emission luminance of the light source.
- a temperature detection unit for detecting a temperature in the liquid crystal display device, and transmission of the liquid crystal panel after the vertical display period of the liquid crystal panel is determined by the input video signal.
- the second technical means in the first technical means the first correlation data between the temperature detected by the temperature detection unit and the panel surface temperature of the liquid crystal panel when the light source is at the maximum emission luminance,
- a memory that stores second correlation data between a light emission luminance of the light source and a correction value for a panel surface temperature at the maximum light emission luminance of the liquid crystal panel; and the panel temperature correction unit changes a light emission luminance of the light source.
- a panel surface temperature at the maximum light emission luminance of the liquid crystal panel corresponding to the temperature detected by the temperature detection unit is obtained, and the light emission luminance with respect to the panel surface temperature is obtained.
- the correction based on the second correlation data is performed based on the second correlation data.
- a third technical means includes a memory that stores correlation data between a temperature detected by the temperature detection unit and a panel surface temperature of the liquid crystal panel for each emission luminance of the light source in the first technical means,
- the panel temperature correction unit corrects the panel surface temperature of the liquid crystal panel corresponding to the temperature detected by the temperature detection unit based on the correlation data when the light emission luminance of the light source changes. It is what.
- the fourth technical means in any one of the first to third technical means, when it is determined that the temperature detected by the temperature detection unit does not change when the light emission luminance of the light source changes,
- the panel temperature correction unit performs the correction.
- a fifth technical means includes an area dividing unit that divides the liquid crystal panel into a plurality of areas according to any one of the first to fourth technical means, and the panel temperature correction unit divides the liquid crystal panel.
- the panel surface temperature for each area is corrected based on the changed light emission luminance
- the enhancement conversion unit is configured for each area of the liquid crystal panel based on the panel surface temperature corrected by the panel temperature correction unit.
- the emphasis conversion parameter is variably controlled.
- a sixth technical means is the fifth technical means, wherein the temperature detection unit has a number of temperature measurement points smaller than the number of the plurality of areas, and each area is based on the temperature of the temperature measurement points. It is characterized by predicting the ambient temperature.
- a seventh technical means is the fifth technical means, wherein the temperature detecting section has the same number of temperature measurement points as the number of the plurality of areas, and the temperature of the temperature measurement points is determined as the ambient temperature of each area. It is characterized by that.
- the eighth technical means is a liquid crystal display device comprising a liquid crystal panel for displaying an input video signal, a light source for illuminating the liquid crystal panel, and a light source luminance control unit for controlling the light emission luminance of the light source, Corresponding to the temperature detected by the temperature detector when the emission luminance of the light source changes, a temperature detector that detects the temperature in the liquid crystal display device, a gamma correction unit that performs gamma correction on the input video signal A panel temperature correction unit that corrects a panel surface temperature of the liquid crystal panel based on the changed light emission luminance, and the gamma correction unit includes a gamma value corresponding to the panel surface temperature corrected by the panel temperature correction unit. And the gradation value of the input video signal is converted and output according to the calculated gamma value.
- the first correlation data between the temperature detected by the temperature detection unit and the panel surface temperature of the liquid crystal panel when the light source is at the maximum emission luminance A memory that stores second correlation data between a light emission luminance of the light source and a correction value for a panel surface temperature at the maximum light emission luminance of the liquid crystal panel; and the panel temperature correction unit changes a light emission luminance of the light source. Then, based on the first correlation data, a panel surface temperature at the maximum light emission luminance of the liquid crystal panel corresponding to the temperature detected by the temperature detection unit is obtained, and the light emission luminance with respect to the panel surface temperature is obtained. The correction based on the second correlation data is performed based on the second correlation data.
- a tenth technical means includes, in the eighth technical means, a memory that stores correlation data between the temperature detected by the temperature detection unit and the panel surface temperature of the liquid crystal panel for each emission luminance of the light source,
- the panel temperature correction unit corrects the panel surface temperature of the liquid crystal panel corresponding to the temperature detected by the temperature detection unit based on the correlation data when the light emission luminance of the light source changes. It is what.
- the gamma correction unit includes a panel surface temperature at the maximum light emission luminance of the liquid crystal panel and a gamma setting value preset in the liquid crystal display device.
- the gamma value corresponding to the panel surface temperature corrected by the panel temperature correction unit is calculated based on the third correlation data with the correction value for.
- the gamma value calculated by the gamma correction unit and the liquid crystal when the light emission luminance of the light source is changed by a user operation input is changed from the gamma setting value to the calculated gamma value at the same time when the light emission luminance of the light source is changed when it is determined that the gamma setting value preset in the display device is different. is there.
- the gamma correction unit calculates when the light emission luminance of the light source automatically changes according to a change in ambient brightness.
- the gamma value is gradually changed from the gamma setting value to the calculated gamma value.
- the fourteenth technical means determines in any one of the eighth to thirteenth technical means that when the light emission luminance of the light source changes, the temperature detected by the temperature detector does not change by a predetermined value or more.
- the panel temperature correction unit corrects the panel surface temperature of the liquid crystal panel corresponding to the temperature detected by the temperature detection unit based on the light emission luminance.
- the gamma correction unit converts the gamma value corresponding to the panel surface temperature corrected by the panel temperature correction unit to white, red, Calculated for each green and blue, and if the gamma value of the white and the gamma value of the green are determined to be equal, determine whether the gamma value of each of the red and blue is equal to the gamma value of the green When it is determined that the red and blue gamma values are not equal to the green gamma value, the red and blue gamma values are adjusted to be the green gamma values. It is what.
- a sixteenth technical means includes an area dividing unit that divides the liquid crystal panel into a plurality of areas according to any one of the eighth to fourteenth technical means, and the panel temperature correction unit divides the liquid crystal panel.
- the panel surface temperature for each area is corrected based on the changed light emission luminance, and the gamma correction unit is configured for each area of the liquid crystal panel based on the panel surface temperature corrected by the panel temperature correction unit.
- a gamma value is calculated, and the gradation value of the input video signal is converted for each area according to the calculated gamma value and output.
- a seventeenth technical means is the sixteenth technical means, wherein the temperature detection unit has a number of temperature measurement points smaller than the number of the plurality of areas, and each area is determined based on the temperature of the temperature measurement points. It is characterized by predicting the ambient temperature.
- the temperature detection unit has the same number of temperature measurement points as the number of the plurality of areas, and the temperature of the temperature measurement points is determined as the ambient temperature of each area. It is characterized by that.
- the gamma correction unit calculates a gamma value corresponding to the panel surface temperature corrected by the panel temperature correction unit for each area. Calculated for each of white, red, green, and blue, and if it is determined that the gamma value of the white and the gamma value of the green are equal, are the gamma values of the red and blue and the green gamma value equal? For each area, and if it is determined that the red and blue gamma values are not equal to the green gamma value, the red and blue gamma values are determined for each area. It is characterized by adjusting to a green gamma value.
- the overshoot drive voltage can be changed according to the change in the panel surface temperature. Can be executed. Further, according to the present invention, even when the panel surface temperature changes due to a change in the light emission luminance of the backlight, a gamma value corresponding to the change in the panel surface temperature can be calculated, so that an appropriate gamma correction is performed. can do.
- FIG. 1 is a block diagram illustrating a schematic configuration example of a liquid crystal display device according to a first embodiment of the present invention. It is a figure which shows an example of the OS setting value table which consists of an emphasis conversion parameter. It is a figure which shows an example of the 1st correlation data which shows the correlation of sensor temperature-panel surface temperature, and the 2nd correlation data which shows the correlation of backlight brightness-temperature correction value. It is a figure for demonstrating an example of the method of estimating a panel surface temperature from backlight brightness
- FIG. 11 is a flowchart for explaining an example of a method for performing gamma correction by estimating the panel surface temperature from the backlight luminance by the liquid crystal display device shown in FIG. 10. It is a flowchart for demonstrating an example of the chromaticity deviation correction method by this invention. It is a figure which shows an example of the distribution state of the panel surface temperature for every area which divided
- FIG. 1 is a diagram showing a configuration example of a backlight applicable to the liquid crystal display device of the present invention.
- the backlight of this example is configured as an array type LED backlight.
- a plurality of LED substrates 101 are arranged on a chassis 105.
- the LED substrate 101 has a horizontally long rectangular strip shape, and is arranged so that the longitudinal direction of the rectangle coincides with the horizontal direction of the screen of the liquid crystal display device.
- FIG. 1 illustrates an array-type LED backlight 10 applied to a 40-inch screen liquid crystal display device.
- the LED substrate 101 is divided into two in the horizontal direction, and two LED substrates 101 in each row are arranged in 10 columns in the vertical direction.
- the LED board 101 generally has vertical and horizontal maximum outer dimensions at the time of manufacture, that is, a standard size.
- the standard length varies depending on the material of the LED substrate 101 and the manufacturing apparatus, but for example, the vertical length is 510 mm and the horizontal length is 340 mm.
- the LED substrate 101 is divided into several parts. In the embodiment according to the present invention, such division of the LED substrate 101 in the horizontal direction is not essential, and here, an example of a configuration to which the present invention can be applied is shown.
- Each LED board 101 has a plurality of (eight here) LEDs 102 arranged in a straight line. That is, the array type LED backlight 10 of FIG. 1 uses a total of 160 LEDs 102 over the entire screen. In addition, the LEDs 102 as a whole are arranged in a hexagonal lattice shape. In the hexagonal lattice arrangement, another LED 102 is arranged at the apex of a virtual regular hexagon formed around a certain LED 102. Thereby, the backlight 10 can irradiate a uniform backlight light with respect to a liquid crystal panel.
- the LEDs 102 mounted on each LED substrate 101 are connected in series with each other by a wiring pattern (not shown) formed on each LED substrate 101.
- a harness 103 is provided to connect the LED boards 101 divided in two in the horizontal direction
- a harness 104 is provided to connect one LED board 101 and an external driver board.
- a connector 106 to which the harnesses 103 and 104 are connected is installed on each LED board 101.
- Each LED board 101 is fixed to the chassis 105 by a screw (not shown) disposed in the vicinity of each connector 106.
- the backlight 10 includes an LED driver mounted on a driver board (drive circuit board) (not shown).
- the LED driver supplies current to the LEDs 102 connected in series, and drives the LEDs 102 by current, PWM (pulse width modulation) control, or both.
- PWM pulse width modulation
- the number of LEDs usually differs depending on the size of the screen.
- the number of units of the LED substrate 101 in which two sheets are arranged in one row is 10, for example, the number of units is 9 for 32 inches and the unit for 46 inches.
- the number is 12, and the number of units of the LED substrate 101 (that is, the number of LEDs) is appropriately changed according to the size of the screen, the required luminance, and the like.
- the number of LEDs and the number of LEDs per substrate are examples, and the present invention does not limit the number of LEDs or the number of units.
- the present invention can also be applied to a backlight in which CCFLs (cold cathode fluorescent lamps) are arranged in parallel.
- CCFLs cold cathode fluorescent lamps
- FIG. 2 is a block diagram showing a schematic configuration example of the liquid crystal display device according to the first embodiment of the present invention.
- the liquid crystal display device includes a frame frequency conversion unit 1, an emphasis conversion unit 2, a ROM 3, an electrode drive unit 4, a liquid crystal panel 5, a frame memory 6, a synchronization extraction unit 7, a main microcomputer 8, a light source drive unit 9, a backlight 10, and a memory. 11, a monitor microcomputer 12, a temperature sensor 13, a light receiving unit 14, and an area dividing unit 15.
- the synchronization extraction unit 7 extracts a vertical / horizontal synchronization signal from an input image signal (for example, a 60 Hz progressive scan signal).
- the main microcomputer 8 includes a control CPU, and controls the operation of each unit based on the vertical / horizontal synchronization signal extracted by the synchronization extraction unit 7.
- the frame frequency conversion unit 1 converts the frame frequency of the input image signal to, for example, twice (120 Hz) based on the control signal from the main microcomputer 8.
- the frame frequency conversion unit 1 is described as an example. However, the frame frequency conversion unit 1 may not be included.
- the frame frequency conversion unit 1 performs frequency conversion based on a control signal from the main microcomputer 8 so that an image for one frame of the two-input image signal has a double frame frequency (120 Hz).
- image signals having a frame display period (vertical display period) on the liquid crystal panel 5 of 1/120 seconds (about 8.3 msec) are continuously output.
- the parameter is stored.
- an OS (overshoot) setting value table is stored that includes enhancement conversion parameters for nine representative gradations for every 32 gradations before and after one vertical display period. Note that these gradation conversion parameters are obtained from actual measured values of the optical response characteristics of the liquid crystal panel 5.
- Image data (Previous Data) before the period is read and output to the enhancement conversion unit 2.
- the enhancement conversion unit 2 reads the corresponding gradation conversion parameter from the gradation transition of the image data before and after one frame period with reference to the OS setting value table of the ROM 3, and uses this gradation conversion parameter for one frame period. After that, the liquid crystal obtains an enhancement conversion signal (writing gradation data) that provides the transmittance determined by the current image data, and outputs it to the electrode driver 4.
- the electrode driving unit 4 performs writing scanning of the image signal in one frame cycle of the input image signal.
- the main microcomputer 8 outputs a control signal for controlling turning on / off of the backlight 10 to the light source driving unit 9 based on the vertical synchronization signal extracted by the synchronization extracting unit 7.
- the light source drive unit 9 is composed of, for example, an FPGA (Field Programmable Gate Array), and performs lighting control of the backlight 10 in accordance with a control signal output from the main microcomputer 8.
- the emphasis conversion parameter is stored in the ROM 3, but instead of using the ROM 3, for example, a two-dimensional function f (pre, curl) having a gradation before transition and a gradation after transition as variables. ) May be prepared, and an enhancement conversion parameter that compensates for the optical response characteristics of the liquid crystal panel 5 with respect to the vertical display period (scanning period) may be used.
- a two-dimensional function f pre, curl
- an enhancement conversion parameter that compensates for the optical response characteristics of the liquid crystal panel 5 with respect to the vertical display period (scanning period) may be used.
- the monitor microcomputer 12 is connected to a light receiving unit 14 that receives an operation signal from a remote controller (not shown) operated by a user, and is connected to a temperature sensor 13 such as a thermistor.
- the temperature sensor 13 is installed on, for example, a circuit board in the liquid crystal display device, and measures the temperature in the device.
- the temperature measured by the temperature sensor 13 is referred to as a sensor temperature.
- the monitor microcomputer 12 is connected to the main microcomputer 8 and transmits an operation signal from the remote controller, a sensor temperature from the temperature sensor 13, and the like to the main microcomputer 8.
- the memory 11 stores correlation data shown in FIG. 4 to be described later, that is, a first temperature between the temperature detected by the temperature sensor 13 when the backlight 10 is at the maximum light emission luminance and the panel surface temperature of the liquid crystal panel 5. Correlation data and second correlation data of the light emission luminance of the backlight 10 and the correction value for the panel surface temperature at the maximum light emission luminance of the liquid crystal panel 5 are stored, and the main microcomputer 8 stores these correlation data. You can refer to it as necessary.
- the liquid crystal display device includes a liquid crystal panel 5 that displays an input video signal, a backlight 10 that is a light source that illuminates the liquid crystal panel 5, and a light source luminance control unit that controls the light emission luminance of the backlight 10. Is provided.
- the light source luminance control unit is realized by the main microcomputer 8 and the light source driving unit 9.
- the liquid crystal display device determines the transmittance of the liquid crystal panel 5 as the input video signal after the elapse of one vertical display period of the liquid crystal panel 5 and the temperature sensor 13 corresponding to the temperature detection unit that detects the temperature in the liquid crystal display device.
- An enhancement conversion unit 2 that obtains an enhancement conversion parameter for reaching the transmittance and outputs a voltage signal applied to the liquid crystal panel 5 based on the enhancement conversion parameter, and a temperature sensor when the emission luminance of the backlight 10 changes.
- a panel temperature correction unit that corrects the panel surface temperature of the liquid crystal panel 5 corresponding to the temperature detected in 13 based on the changed light emission luminance, and the enhancement conversion unit 2 is a panel corrected by the panel temperature correction unit.
- the enhancement conversion parameter is variably controlled based on the surface temperature.
- the panel temperature correction unit is realized by the main microcomputer 8.
- FIG. 4 is a diagram illustrating an example of first correlation data indicating a correlation between sensor temperature and panel surface temperature, and second correlation data indicating a correlation between backlight luminance and temperature correction value.
- FIG. 4A shows an example of the first correlation data, where the vertical axis represents the panel surface temperature (unit: ° C.), and the horizontal axis represents the sensor temperature (unit: ° C.).
- y (5 ⁇ 10 ⁇ 5 ) x 3 ⁇ 0.004x 2 + 1.230x ⁇ 0.046
- R 2 0.999 (R 2 is a correlation coefficient) It can be expressed as.
- FIG. 4B shows an example of second correlation data, where the horizontal axis represents backlight luminance (duty ratio, unit:%), and the vertical axis represents temperature correction value (change amount of panel surface temperature, unit: ° C).
- FIG. 5 is a diagram for explaining an example of a method for estimating the panel surface temperature from the backlight luminance.
- an item “brightness (brightness)” is provided as an item that can be set by a user operation.
- the backlight luminance is divided into 33 levels from +16 (maximum luminance) to -16 (minimum luminance), and each level is associated with a backlight duty.
- the backlight duty For example, when the user sets the luminance “+14” using a remote controller or the like, “95.0%” is set as the backlight duty.
- the sensor temperature does not change, but the panel surface temperature changes. Estimate the panel surface temperature from the duty.
- the monitor microcomputer 12 detects the sensor temperature of the temperature sensor 13 when detecting the change of the backlight duty by the user operation. Then, the monitor microcomputer 12 transmits the detected sensor temperature to the main microcomputer 8. Since the main microcomputer 8 periodically receives the sensor temperature from the monitor microcomputer 12, it can determine whether the temperature has changed by comparing the sensor temperature at the time of changing the duty with the sensor temperature immediately before it. . Then, the main microcomputer 8 refers to the first correlation data shown in FIG. 4A based on the sensor temperature at the time of changing the duty, and obtains the panel surface temperature corresponding to the sensor temperature at the duty of 100%. The panel surface temperature at this time corresponds to the panel surface temperature “A” in FIG.
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B based on the luminance (+14) changed by the user, and obtains a temperature correction value corresponding to the backlight duty.
- the relationship between the backlight duty and the temperature correction value can be linearly approximated.
- the panel surface temperature changes by a ° C. when the luminance is changed by one step. It will be explained as a thing.
- the change amount of the panel surface temperature is “2a”.
- the main microcomputer 8 can estimate the panel surface temperature corresponding to the luminance (+14) of the backlight 10 as “A-2a” ° C.
- the panel surface temperature at the maximum light emission luminance of the corresponding liquid crystal panel 5 is obtained, and the actual light emission luminance is calculated based on the second correlation data (FIG. 4B) stored in the memory 11 with respect to this panel surface temperature. Make corrections. Thereby, the exact panel surface temperature corresponding to a luminance change can be estimated.
- FIG. 6 is a diagram showing an example of an emphasis conversion parameter switching table for switching the OS setting value table shown in FIG.
- This enhancement conversion parameter switching table is stored in the memory 11 (or ROM 3).
- the table number is, for example, the number of the OS setting value table including the emphasis conversion parameters shown in FIG. 3.
- eight types of OS setting value tables corresponding to the table numbers 0 to 7 are stored in the ROM 3. Yes.
- OS setting value tables are associated with the sensor temperature and the panel surface temperature, respectively, and can be switched by this emphasis conversion parameter switching table.
- the relationship between the sensor temperature and the panel surface temperature is obtained from the first correlation data shown in FIG. That is, it is obtained from the correlation between the sensor temperature and the panel surface temperature when the duty is 100% (maximum light emission luminance).
- the OS setting value table with the table number “0” is selected and the sensor temperature is 1 ° C.
- the OS setting value table with the table number “1” is selected.
- one of eight types of OS setting value tables is selected according to the sensor temperature.
- the main microcomputer 8 refers to the emphasis conversion parameter switching table (FIG. 6) stored in the memory 11 based on the panel surface temperature obtained by the method of the present invention described in FIG.
- the table number is determined, and this table number is output to the emphasis conversion unit 2.
- the emphasis conversion unit 2 determines the OS setting value table in the ROM 3 based on the table number from the main microcomputer 8.
- the enhancement conversion unit 2 reads the corresponding gradation conversion parameter from the gradation transition of the image data before and after one frame period with reference to the determined OS setting value table, and uses this gradation conversion parameter.
- the liquid crystal After a lapse of one frame period, the liquid crystal obtains an enhancement conversion signal (writing gradation data) that has a transmittance determined by the current image data, and outputs it to the electrode drive unit 4.
- the electrode driving unit 4 performs writing scanning of the image signal in one frame cycle of the input image signal.
- the OS set value table cannot be switched unless the sensor temperature changes.
- the maximum light emission occurs when the backlight emission luminance changes. Based on the correlation data between the sensor temperature in brightness and the panel surface temperature, the panel surface temperature of the liquid crystal panel corresponding to the temperature detected by the temperature sensor is obtained, and the correction based on the changed emission brightness is performed on this panel surface temperature. Therefore, it is possible to estimate an accurate panel surface temperature corresponding to the luminance change and thereby switch the OS setting value table.
- the panel surface temperature is estimated to be 17 ° C. or higher and lower than 22 ° C., and the OS setting value table of table number 2 is selected.
- the panel surface temperature is changed to, for example, 16 ° C. without changing the sensor temperature. It is necessary to switch to the OS setting value table.
- the panel surface temperature of 16 ° C. can be estimated. It is possible to switch to one table.
- FIG. 7 is a flowchart for explaining an example of a method for estimating the panel surface temperature from the backlight luminance by the liquid crystal display device shown in FIG.
- the main microcomputer 8 determines whether or not the brightness of the backlight 10 has been changed according to user settings or the like (step S1). If it is determined that the brightness of the backlight 10 has not been changed (NO), step In S1, a transition is made to a standby state. If it is determined in step S1 that the brightness of the backlight 10 has been changed (in the case of YES), the sensor temperature detected by the temperature sensor 13 is detected (step S2).
- the main microcomputer 8 determines whether or not the sensor temperature has changed before and after the luminance change of the backlight 10 (step S3). For example, it may be determined whether the sensor temperature has changed by a predetermined value (for example, 2 ° C.) or more. In this step S3, when it is determined that the sensor temperature has changed (in the case of YES), it is determined whether or not switching of the OS setting value table is necessary based on the changed sensor temperature (step S4). If it is determined in step S3 that the sensor temperature has not changed (NO), the first correlation data (FIG. 4A) is referred to based on the sensor temperature, and the corresponding panel surface temperature is determined. Obtained (step S5).
- a predetermined value for example, 2 ° C.
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B and corrects the panel surface temperature obtained in step S5 based on the changed backlight luminance (step S5). S6). Then, the main microcomputer 8 refers to the emphasis conversion parameter switching table shown in FIG. 6, specifies the OS set value table (table number) corresponding to the corrected panel surface temperature (step S7), and the table is switched. It is determined whether or not it is necessary (step S8).
- step S8 When it is determined in step S8 that the OS setting value table needs to be switched (in the case of YES), the emphasis conversion unit 2 accesses the ROM 3 and obtains the emphasis conversion parameter from the switched OS setting value table (step S8). S9), an applied voltage signal to the liquid crystal panel 5 is output based on the emphasis conversion parameter (step S10). If it is determined in step S8 that switching of the OS setting value table is not necessary (in the case of NO), the emphasis conversion unit 3 accesses the ROM 3 and obtains an emphasis conversion parameter from the current OS setting value table (step S8). S11), the process proceeds to step S10.
- step S4 when it is determined that the table needs to be switched due to the changed sensor temperature (in the case of YES), the process proceeds to step S9. In step S4, it is determined that it is not necessary to switch the table. If (NO), the process proceeds to step S5.
- the backlight 10 is actually set to the maximum light emission luminance (backlight duty 100%), and the correlation between the sensor temperature and the panel surface temperature is obtained. You may save it for each light duty.
- correlation data is obtained such as backlight duty (luminance) 100%, 90%, 80%,...,
- the plurality of correlation data is stored in the memory 11.
- the brightness interval is not limited to 10% and may be set as appropriate.
- the main microcomputer 8 refers to the correlation data of the luminance 90% and obtains the panel surface temperature corresponding to the sensor temperature at this time.
- the panel surface temperature corresponding to the change in the backlight luminance is set as in the method using the first correlation data and the second correlation data. Can be sought.
- the panel surface temperature near the approximate center of the liquid crystal panel 5 has been obtained so far, but the panel surface temperature varies depending on the area of the liquid crystal panel 5. For this reason, there is a possibility that appropriate OS driving may not be executed depending on the area. Therefore, in this embodiment, the liquid crystal panel 5 is divided into a plurality of areas, and the panel surface temperature is obtained for each area. And the correction
- FIG. 9 is a diagram showing an example of the distribution state of the panel surface temperature for each area obtained by dividing the liquid crystal panel 5.
- the liquid crystal display device shown in FIG. 2 includes an area dividing unit 15 that divides the liquid crystal panel 5 into a plurality of areas. In this example, the liquid crystal panel 5 is divided into nine areas 5a to 5i. For each of these areas 5a to 5i, the first correlation data shown in FIG. 4 (A) and FIG. The second correlation data shown in FIG. That is, the first correlation data and the second correlation data corresponding to each area are prepared in advance and stored in the memory 11.
- the main microcomputer 8 corrects and emphasizes the panel surface temperature for each area obtained by dividing the liquid crystal panel 5 based on the changed light emission luminance based on the first correlation data and the second correlation data.
- the conversion unit 2 variably controls the enhancement conversion parameter for each area of the liquid crystal panel 5 based on the panel surface temperature corrected by the main microcomputer 8.
- the monitor microcomputer 12 detects the sensor temperature of the temperature sensor 13 for each of the areas 5a to 5i.
- the temperature sensor 13 has a smaller number of temperature measurement points than the number of the plurality of areas, and may predict the sensor temperature (ambient temperature) of each area based on the temperature of the temperature measurement point. Good.
- the temperature measurement points can be set between 1 and 8. For example, when a temperature measurement point is provided near the area 5e at the center of the panel, the temperature at this temperature measurement point is set as the sensor temperature of the area 5e.
- the sensor temperatures of the other areas 5a to 5d and 5f to 5i are predicted from the sensor temperature of the area 5e (that is, the temperature at the temperature measurement point). Specifically, a temperature difference between the temperature of each of the areas 5a to 5d and 5f to 5i and the temperature of the area 5e can be measured in advance and predicted based on this temperature difference.
- the temperature sensor 13 may have the same number of temperature measurement points as the number of the plurality of areas, and the temperature of the temperature measurement points may be the sensor temperature of each area. In this example, since the number of areas is nine, there are nine temperature measurement points. Specifically, temperature measurement points are provided in the vicinity of the nine areas 5a to 5i, and the temperature at each temperature measurement point is set as the sensor temperature of each area 5a to 5i.
- the monitor microcomputer 12 transmits the sensor temperatures of the areas 5a to 5i detected as described above to the main microcomputer 8. Since the main microcomputer 8 periodically receives the sensor temperatures of the areas 5a to 5i from the monitor microcomputer 12, the sensor temperature at the time of changing the duty and the sensor temperature immediately before it are compared for each area, and the temperature changes. It can be determined whether or not. Then, for example, for the area 5a, the main microcomputer 8 refers to the first correlation data shown in FIG. 4A based on the sensor temperature when the duty is changed, and corresponds to the sensor temperature when the duty is 100%. Determine the panel surface temperature. The panel surface temperature at this time corresponds to “A” of the panel surface temperature in FIG. 5 described above. Note that “A” of the panel surface temperature is a value that varies depending on the sensor temperature of each area. In the example of FIG. 9, the panel surface temperature of the area 5a is 42.1 ° C.
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B with the brightness (+14) changed by the user for the area 5a, and the temperature correction value corresponding to the backlight duty Ask for.
- the amount of change in the panel surface temperature is “2a”.
- the change amount “a” of the panel surface temperature indicates that the panel surface temperature changes by a ° C. when the luminance is changed by one step, but this value varies depending on each area.
- the main microcomputer 8 can estimate the panel surface temperature of the area 5a corresponding to the luminance (+14) of the backlight 10 as “A-2a” ° C.
- the other areas 5b to 5i can be estimated by the same method.
- the panel surface temperature at the maximum light emission luminance of the liquid crystal panel 5 corresponding to each sensor temperature is obtained, and the second correlation data (for each area) stored in the memory 11 with respect to the panel surface temperature for each area ( Based on FIG. 4 (B)), correction by actual light emission luminance is performed. In this way, an accurate panel surface temperature corresponding to the luminance change can be estimated for each area of the liquid crystal panel 5.
- the main microcomputer 8 determines the table number by referring to the above-described enhancement conversion parameter switching table shown in FIG. 6 based on the panel surface temperature for each area estimated as described above. Is output to the emphasis conversion unit 2. Since the processing in the emphasis conversion unit 2 is as described above, a description thereof is omitted here.
- the backlight brightness is changed according to user settings.
- the present invention automatically performs backlight brightness according to the average brightness (APL: Average (Picture Level) of the liquid crystal panel (screen).
- APL Average (Picture Level) of the liquid crystal panel (screen).
- the present invention can be similarly applied even when an active backlight technology that changes the above is applied.
- FIG. 10 is a block diagram showing a schematic configuration example of a liquid crystal display device according to the second embodiment of the present invention.
- the liquid crystal display device includes a frame frequency conversion unit 1, a ROM 3, an electrode drive unit 4, a liquid crystal panel 5, a synchronization extraction unit 7, a main microcomputer 8, a light source drive unit 9, a backlight 10, and a memory. 11, a monitor microcomputer 12, a temperature sensor 13, a light receiving unit 14, an area dividing unit 15, and a gamma correction unit 16. It should be noted that repeated description of parts denoted by the same reference numerals is omitted.
- the ROM 3 stores an LUT having conversion data for performing gamma correction on the input image signal.
- An example of this LUT is shown in FIG.
- the gamma correction unit 16 converts the gradation value of the input image signal by referring to the LUT in FIG. 11 when performing gamma correction on the input image signal, and outputs the converted image signal to the electrode driving unit 4. To do.
- the electrode driving unit 4 performs writing scanning of the image signal in one frame cycle of the input image signal.
- the main microcomputer 8 outputs a control signal for controlling turning on / off of the backlight 10 to the light source driving unit 9 based on the vertical synchronization signal extracted by the synchronization extracting unit 7.
- the light source drive unit 9 is composed of, for example, an FPGA (Field Programmable Gate Array) and performs lighting control of the backlight 10 according to a control signal output from the main microcomputer 8.
- the monitor microcomputer 12 is connected to a light receiving unit 14 that receives an operation signal from a remote controller (not shown) operated by a user, and is connected to a temperature sensor 13 such as a thermistor.
- the temperature sensor 13 is installed on, for example, a circuit board in the liquid crystal display device, and measures the temperature in the device.
- the temperature measured by the temperature sensor 13 is referred to as a sensor temperature.
- the monitor microcomputer 12 is connected to the main microcomputer 8 and transmits an operation signal from the remote controller, a sensor temperature from the temperature sensor 13, and the like to the main microcomputer 8.
- the memory 11 stores the correlation data shown in FIG. 4 described above, that is, the first temperature between the temperature detected by the temperature sensor 13 when the backlight 10 is at the maximum light emission luminance and the panel surface temperature of the liquid crystal panel 5.
- the second correlation data of the correction value for the panel surface temperature at the maximum emission luminance of the liquid crystal panel 5 and the main microcomputer 8 stores these correlation data. Can be referred to as necessary.
- the liquid crystal display device includes a liquid crystal panel 5 that displays an input video signal, a backlight 10 that is a light source that illuminates the liquid crystal panel 5, and a light source luminance control unit that controls the light emission luminance of the backlight 10. Is provided.
- the light source luminance control unit is realized by the main microcomputer 8 and the light source driving unit 9.
- the liquid crystal display device has a temperature sensor 13 that corresponds to a temperature detection unit that detects the temperature in the liquid crystal display device, a gamma correction unit 16 that performs gamma correction on the input video signal, and the emission luminance of the backlight 10 has changed.
- a panel temperature correction unit that corrects the panel surface temperature of the liquid crystal panel 5 corresponding to the temperature detected by the temperature sensor 13 based on the changed light emission luminance, and the gamma correction unit 16 includes a panel temperature correction unit.
- the gamma value corresponding to the panel surface temperature corrected by the above is calculated, and the gradation value of the input video signal is converted and output according to the calculated gamma value.
- the panel temperature correction unit is realized by the main microcomputer 8.
- FIG. 12 is a diagram showing an example of correlation data between the sensor temperature and the gamma value by the temperature sensor 13 at the maximum light emission luminance, where the vertical axis is the gamma value and the horizontal axis is the sensor temperature (unit: ° C.).
- the correlation data indicated by the solid line is actually the correlation between the sensor temperature and the gamma value (actual measurement value) with the backlight 10 set to the maximum light emission luminance (duty 100%), and can be approximated by the third order. it can.
- the liquid crystal display device of FIG. 10 is set to have a gamma value of 2.2, for example, when the sensor temperature is 25 ° C. (room temperature) and the maximum light emission luminance is achieved. According to this correlation data, it can be seen that the gamma value tends to decrease as the sensor temperature increases.
- the correlation data at the maximum light emission luminance shown in FIG. 12 is stored in the ROM 3 and can be appropriately referred to by the gamma correction unit 16.
- the gamma correction unit 16 can refer to the correlation data in the ROM 3 and calculate the corresponding gamma value. Then, the gamma correction unit 16 converts the input image signal according to the calculated gamma value and outputs it.
- the gamma correction at this time may be performed by using the above-described equation (2), or by holding a LUT having a plurality of representative gamma values in the ROM 3 in advance and referring to the corresponding LUT. Also good.
- the panel surface temperature changes quickly, but the sensor temperature may not change immediately.
- the gamma value is set to the set value (2.2) at the same sensor temperature (25 ° C.) as shown by the correlation data shown by the dotted line in FIG. I know it will be more misaligned.
- FIG. 4 shows an example of the first correlation data indicating the correlation between the sensor temperature and the panel surface temperature, and the second correlation data indicating the correlation between the backlight luminance and the temperature correction value.
- FIG. 4A shows an example of the first correlation data, where the vertical axis represents the panel surface temperature (unit: ° C.), and the horizontal axis represents the sensor temperature (unit: ° C.).
- FIG. 4B shows an example of second correlation data, where the horizontal axis represents backlight luminance (duty ratio, unit:%), and the vertical axis represents temperature correction value (change amount of panel surface temperature, unit: ° C).
- an item “brightness (brightness)” is provided as an item that can be set by a user operation.
- the backlight luminance is divided into 33 levels from +16 (maximum luminance) to -16 (minimum luminance), and each level is associated with a backlight duty.
- the backlight duty For example, when the user sets the luminance “+14” using a remote controller or the like, “95.0%” is set as the backlight duty.
- the sensor temperature does not change, but the panel surface temperature changes. Estimate the panel surface temperature from the duty.
- the monitor microcomputer 12 detects the sensor temperature of the temperature sensor 13 when detecting the change of the backlight duty by the user operation. Then, the monitor microcomputer 12 transmits the detected sensor temperature to the main microcomputer 8. Since the main microcomputer 8 periodically receives the sensor temperature from the monitor microcomputer 12, it can determine whether the temperature has changed by comparing the sensor temperature at the time of changing the duty with the sensor temperature immediately before it. . Then, the main microcomputer 8 refers to the first correlation data shown in FIG. 4A based on the sensor temperature at the time of changing the duty, and obtains the panel surface temperature corresponding to the sensor temperature at the duty of 100%. The panel surface temperature at this time corresponds to the panel surface temperature “A” in FIG.
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B based on the luminance (+14) changed by the user, and obtains a temperature correction value corresponding to the backlight duty.
- the relationship between the backlight duty and the temperature correction value can be linearly approximated.
- the panel surface temperature changes by a ° C. when the luminance is changed by one step. It will be explained as a thing.
- the change amount of the panel surface temperature is “2a”.
- the main microcomputer 8 can estimate the panel surface temperature corresponding to the luminance (+14) of the backlight 10 as “A-2a” ° C.
- the panel surface temperature at the maximum light emission luminance of the corresponding liquid crystal panel 5 is obtained, and the actual light emission luminance is calculated based on the second correlation data (FIG. 4B) stored in the memory 11 with respect to this panel surface temperature. Make corrections. Thereby, the exact panel surface temperature corresponding to a luminance change can be estimated.
- FIG. 13 is a diagram showing an example of third correlation data indicating the correlation between the panel surface temperature and the gamma correction value.
- the horizontal axis represents the panel surface temperature (unit: ° C.)
- the vertical axis represents the gamma correction value (gamma value change amount).
- the third correlation data actually indicates the correlation between the panel surface temperature at the maximum light emission luminance of the liquid crystal panel 5 and the gamma correction value with respect to the gamma setting value (2.2) preset in the liquid crystal display device.
- the gamma correction value when there is no deviation (change) with respect to the gamma setting value (2.2) is set to zero.
- the third correlation data is stored in the ROM 3 and can be appropriately referred to by the gamma correction unit 16.
- the main microcomputer 8 transmits the panel surface temperature obtained by the above-described method of the present invention to the gamma correction unit 16.
- the gamma correction value ⁇ f3 (Tp) is obtained with reference to the third correlation data in FIG.
- the gamma correction value ⁇ can be added to 2.2 (gamma setting value) to obtain the gamma value ⁇ to be corrected.
- the gamma correction at this time may use the above-described equation (2) for the gamma value ⁇ to be corrected, or hold the LUT of a plurality of representative gamma values in the ROM 3 in advance. It may be performed by referring to the corresponding LUT.
- the main microcomputer 8 determines the gamma calculation value calculated by the gamma correction unit 16 and the gamma setting value preset in the liquid crystal display device when the light emission luminance of the backlight 10 is changed by the user's operation input. It may be determined whether or not (2.2) is different. If the gamma calculation value and the gamma setting value are different from each other as a result of the determination, control is performed so that the gamma setting value is changed to the gamma calculation value simultaneously with the change in the light emission luminance of the backlight 10.
- the gamma value is simultaneously changed according to the change in the light emission luminance of the backlight 10, it is expected that the image quality will change suddenly, but the user intentionally emits the light from the backlight 10. Since the luminance is changed, it is considered that the change on the image quality has little influence on the user.
- the gamma calculation value calculated by the gamma correction unit 16 and the gamma setting preset in the liquid crystal display device are used. It may be determined whether or not the value (2.2) is different.
- the liquid crystal display device of this example has an OPC (Optical Picture Control) function (also called a brightness sensor) (not shown), detects ambient brightness, and automatically adjusts the luminance of the backlight 10 according to the detection result. It is configured to control automatically. If the gamma calculation value and the gamma setting value are different from each other as a result of the determination, control is performed so that the gamma setting value is gradually changed from the gamma setting value. In this example, since the user does not intentionally change the light emission luminance of the backlight 10, the gamma value is gradually changed so as not to make the user feel as uncomfortable as possible. Note that the method of changing the gamma value may be either gradual or stepwise.
- the gamma correction is performed in accordance with the change in the sensor temperature, but also when the panel surface temperature changes due to the change in the light emission luminance of the backlight, the sensor temperature and the panel at the maximum light emission luminance.
- First correlation data with the surface temperature second correlation data between the light emission luminance of the backlight and the temperature correction value for the panel surface temperature at the maximum light emission luminance, the panel surface temperature and the gamma setting value at the maximum light emission luminance Since the gamma value corresponding to the change in the panel surface temperature can be calculated based on the third correlation data with the gamma correction value for (2.2), appropriate gamma correction can be executed.
- FIG. 14 is a flowchart for explaining an example of a method of performing gamma correction by estimating the panel surface temperature from the backlight luminance by the liquid crystal display device shown in FIG.
- the main microcomputer 8 determines whether or not the brightness of the backlight 10 has been changed according to user settings or the like (step S11). If it is determined that the brightness of the backlight 10 has not been changed (NO), step In S11, a transition is made to a standby state. If it is determined in step S11 that the luminance of the backlight 10 has been changed (in the case of YES), the sensor temperature detected by the temperature sensor 13 is detected (step S12).
- the main microcomputer 8 determines whether or not the sensor temperature has changed by a predetermined value before and after the luminance change of the backlight 10 (step S13).
- This predetermined value may be set as appropriate, but in this example, it is determined whether the temperature has changed by 2 ° C. or more. If it is determined in step S13 that the sensor temperature has changed (in the case of YES), the corresponding gamma value is calculated based on the changed sensor temperature with reference to the correlation data in FIG. 12 (step S14). The process proceeds to S19. If it is determined in step S13 that the sensor temperature has not changed (in the case of NO), the first correlation data (FIG. 4A) is referred to based on the sensor temperature, and the corresponding panel surface temperature is determined. Obtained (step S15).
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B and corrects the panel surface temperature obtained in step S15 based on the changed backlight luminance (step S15). S16). Then, the gamma correction unit 16 refers to the third correlation data (ROM 3) shown in FIG. 13 based on the corrected panel surface temperature transmitted from the main microcomputer 8, and corresponds to the corrected panel surface temperature.
- the gamma value to be calculated is calculated (step S17), and it is determined whether or not the calculated gamma value is 2.2 (set value) (step S18).
- step S18 when it is determined that the gamma value calculated in step S17 is not 2.2 (in the case of NO), the gamma correction unit 16 performs gamma correction using the gamma value calculated in step S17 ( Step S19). If it is determined in step S18 that the gamma value calculated in step S17 is 2.2 (YES), the gamma correction unit 16 performs gamma correction using the gamma setting value (2.2). It performs (step S20).
- the backlight 10 is actually set to the maximum light emission luminance (backlight duty 100%), and the correlation between the sensor temperature and the panel surface temperature is obtained. You may save it for each light duty.
- correlation data such as backlight duty (luminance) 100%, 90%, 80%,... Is obtained, and the plurality of correlation data is stored in the memory 11. deep.
- the brightness interval is not limited to 10% and may be set as appropriate.
- the main microcomputer 8 refers to the correlation data of the luminance 90% and obtains the panel surface temperature corresponding to the sensor temperature at this time.
- the panel surface temperature corresponding to the change in the backlight luminance is set as in the method using the first correlation data and the second correlation data. Can be sought.
- the gamma value of white (W) can be adjusted according to the change in the panel surface temperature by the gamma correction method described so far.
- the luminance of white (W) is the sum of the luminances of red (R), green (G), and blue (B).
- the gamma correction unit 16 shown in FIG. 10 described above calculates gamma values corresponding to the panel surface temperature corrected by the main microcomputer 8 for each of W, R, G, and B. When it is determined that the gamma value of W and the gamma value of G are equal, it is determined whether the R and B gamma values are equal to the G gamma value. When it is determined that the R and B gamma values are not equal to the G gamma value, the gamma correction unit 16 adjusts the R and B gamma values to be the G gamma values.
- the ratio of the R, G, and B gamma values changes, the R and B gamma values are matched with the G gamma value. Thereby, it is possible to eliminate the chromaticity shift without changing the gamma value of W.
- the term “equal” here includes not only a case where they completely match but also a case where they substantially match.
- a deviation amount between two gamma values is within a predetermined range. What is necessary is just to determine whether it is in (for example within 0.1).
- FIG. 15 is a flowchart for explaining an example of the chromaticity deviation correction method according to the present invention.
- the gamma correction unit 16 determines whether or not the gamma value of W is equal to the gamma value of G (step S21). If the gamma value of W and the gamma value of G are equal (in the case of YES), it is determined whether or not the gamma values of R and B are equal to the gamma value of G (step S22). In step S21, if the gamma value of W and the gamma value of G are not equal (in the case of NO), the process ends without performing chromaticity deviation correction.
- step S22 if the R and B gamma values are equal to the G gamma value (in the case of YES), there is no need to correct the chromaticity deviation, and the processing is terminated.
- step S22 if the R and B gamma values are not equal to the G gamma value (NO), the R and B gamma values are adjusted to be the G gamma value (step S23). ). Thereby, it is possible to perform chromaticity deviation correction without changing the gamma value of W.
- the panel surface temperature near the approximate center of the liquid crystal panel 5 has been obtained so far, but the panel surface temperature varies depending on the area of the liquid crystal panel 5. For this reason, appropriate gamma correction may not be performed depending on the area. Therefore, in this embodiment, the liquid crystal panel 5 is divided into a plurality of areas, and the panel surface temperature is obtained for each area. And the correction
- FIG. 16 is a diagram showing an example of a distribution state of the panel surface temperature for each area obtained by dividing the liquid crystal panel 5.
- the liquid crystal display device shown in FIG. 10 includes an area dividing unit 15 that divides the liquid crystal panel 5 into a plurality of areas. In this example, the liquid crystal panel 5 is divided into nine areas 5a 'to 5i'.
- the second correlation data shown in FIG. 4 (B) is stored in the memory 11, and the third correlation data shown in FIG. That is, the first correlation data and the second correlation data corresponding to each area are prepared in advance, stored in the memory 11, and the third correlation data corresponding to each area is prepared in advance, and this is stored in the ROM 3. Store it.
- the main microcomputer 8 corrects the panel surface temperature for each area into which the liquid crystal panel 5 is divided based on the first correlation data and the second correlation data, based on the changed light emission luminance.
- the correction unit 16 calculates a gamma value for each area of the liquid crystal panel 5 based on the panel surface temperature corrected by the main microcomputer 8, and calculates the gradation value of the input video signal for each area according to the calculated gamma value. Convert and output. If the sensor temperature changes, the corresponding gamma value can be calculated from the correlation data shown in FIG. In this case, correlation data between the sensor temperature by the temperature sensor 13 and the gamma value at the maximum light emission luminance may be stored in the ROM 3 for each area.
- the monitor microcomputer 12 detects the sensor temperature of the temperature sensor 13 for each of the areas 5a ′ to 5i ′.
- the temperature sensor 13 has a smaller number of temperature measurement points than the number of the plurality of areas, and may predict the sensor temperature (ambient temperature) of each area based on the temperature of the temperature measurement point. Good.
- the temperature measurement points can be set between 1 and 8. For example, when a temperature measurement point is provided near the area 5e ′ at the center of the panel, the temperature at this temperature measurement point is set as the sensor temperature of the area 5e ′.
- the sensor temperatures of the other areas 5a ′ to 5d ′ and 5f ′ to 5i ′ are predicted from the sensor temperature of the area 5e ′ (that is, the temperature at the temperature measurement point). Specifically, the temperature difference between the temperature of each of the areas 5a 'to 5d' and 5f 'to 5i' and the temperature of the area 5e 'can be measured in advance and predicted based on this temperature difference.
- the temperature sensor 13 may have the same number of temperature measurement points as the number of the plurality of areas, and the temperature of the temperature measurement points may be the sensor temperature of each area. In this example, since the number of areas is nine, there are nine temperature measurement points. Specifically, temperature measurement points are provided in the vicinity of nine areas 5a ′ to 5i ′, and the temperature at each temperature measurement point is set as the sensor temperature of each area 5a ′ to 5i ′.
- the monitor microcomputer 12 transmits the sensor temperatures of the areas 5a ′ to 5i ′ detected as described above to the main microcomputer 8. Since the main microcomputer 8 periodically receives the sensor temperatures of the areas 5a ′ to 5i ′ from the monitor microcomputer 12, the sensor temperature at the time of changing the duty and the sensor temperature immediately before it are compared for each area. It can be determined whether or not it has changed. Then, for example, for the area 5a ′, the main microcomputer 8 refers to the first correlation data shown in FIG. 4A based on the sensor temperature at the time of changing the duty, and corresponds to the sensor temperature at the time of 100% duty. Determine the panel surface temperature. The panel surface temperature at this time corresponds to “A” of the panel surface temperature in FIG. 5 described above. Note that “A” of the panel surface temperature is a value that varies depending on the sensor temperature of each area. In the example of FIG. 16, the panel surface temperature of the area 5a ′ is 52.1 ° C.
- the main microcomputer 8 refers to the second correlation data shown in FIG. 4B by the brightness (+14) changed by the user for the area 5a ′, and corrects the temperature corresponding to the backlight duty. Find the value.
- the amount of change in the panel surface temperature is “2a”.
- the change amount “a” of the panel surface temperature indicates that the panel surface temperature changes by a ° C. when the luminance is changed by one step, but this value varies depending on each area.
- the main microcomputer 8 can estimate the panel surface temperature of the area 5a ′ corresponding to the luminance (+14) of the backlight 10 as “A ⁇ 2a” ° C.
- the other areas 5b 'to 5i' can be estimated by the same method.
- the panel surface temperature at the maximum light emission luminance of the liquid crystal panel 5 corresponding to each sensor temperature is obtained, and the second correlation data (for each area) stored in the memory 11 with respect to the panel surface temperature for each area ( Based on FIG. 4 (B)), correction by actual light emission luminance is performed. In this way, an accurate panel surface temperature corresponding to the luminance change can be estimated for each area of the liquid crystal panel 5.
- the gamma correction unit 16 refers to the third correlation data shown in FIG. 13 described above based on the panel surface temperature for each area estimated as described above, and performs gamma correction corresponding to each area.
- the value ( ⁇ ) is obtained.
- the gamma correction value ( ⁇ ) is added to 2.2 (gamma setting value) to obtain the gamma value ⁇ to be corrected for each area.
- the chromaticity deviation correction method described with reference to FIG. 15 may be executed for each area. That is, the gamma correction unit 16 calculates a gamma value corresponding to the panel surface temperature corrected by the main microcomputer 8 for each of W, R, G, and B for each area. Are equal to each other, it is determined for each area whether the R and B gamma values are equal to the G gamma value. When it is determined that the R and B gamma values are not equal to the G gamma value, the gamma correction unit 16 converts the R and B gamma values to the G gamma values for each area. Adjust as follows.
- the backlight luminance is changed according to user settings.
- the present invention automatically performs backlight luminance according to the average luminance (APL: Average (Picture Level) of the liquid crystal panel (screen).
- APL Average (Picture Level) of the liquid crystal panel (screen).
- the present invention can be similarly applied even when an active backlight technology that changes the above is applied.
- DESCRIPTION OF SYMBOLS 1 Frame frequency conversion part, 2 ... Emphasis conversion part, 3 ... ROM, 4 ... Electrode drive part, 5 ... Liquid crystal panel, 6 ... Frame memory, 7 ... Synchronization extraction part, 8 ... Main microcomputer, 9 ... Light source drive part, DESCRIPTION OF SYMBOLS 10 ... Back light, 11 ... Memory, 12 ... Monitor microcomputer, 13 ... Temperature sensor, 14 ... Light-receiving part, 15 ... Area division part, 16 ... Gamma correction part, 101 ... LED board, 102 ... LED, 103, 104 ... Harness , 105, 106 ... connectors.
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Abstract
Description
また、本発明は、バックライトの発光輝度の変化によりパネル表面温度が変化した場合でも、適切なガンマ補正を実行できる液晶表示装置を提供すること、を目的とする。
また、本発明によれば、バックライトの発光輝度の変化によりパネル表面温度が変化した場合でも、このパネル表面温度の変化に応じたガンマ値を算出することができるため、適切なガンマ補正を実行することができる。
バックライト10は、シャーシ105上に、複数のLED基板101が配置されている。LED基板101は、横長矩形の短冊形状を有しており、矩形の長手方向が液晶表示装置の画面の水平方向に一致するように配置されている。
なお、本発明に係る実施形態では、このようなLED基板101の横方向への分割は必須ではなく、ここでは本発明の適用可能な構成例を示している。
図2は、本発明の第1の実施形態に係る液晶表示装置の概略構成例を示すブロック図である。液晶表示装置は、フレーム周波数変換部1、強調変換部2、ROM3、電極駆動部4、液晶パネル5、フレームメモリ6、同期抽出部7、メインマイコン8、光源駆動部9、バックライト10、メモリ11、モニタマイコン12、温度センサ13、受光部14、及びエリア分割部15を備えている。
同期抽出部7は、入力画像信号(例えば、60Hzのプログレッシブスキャン信号)から垂直/水平同期信号を抽出する。メインマイコン8は、制御CPUを含み、同期抽出部7で抽出された垂直/水平同期信号に基づいて、各部の動作制御を行う。フレーム周波数変換部1は、メインマイコン8からの制御信号に基づいて、入力画像信号のフレーム周波数を例えば2倍(120Hz)に変換する。なお、本例では、フレーム周波数変換部1を備えるものとして説明するが、このフレーム周波数変換部1を含まない構成としてもよい。
y=(5×10-5)x3-0.004x2+1.230x-0.046 …式(1)
R2=0.999(R2は相関係数)
と表すことができる。
図10は、本発明の第2の実施形態に係る液晶表示装置の概略構成例を示すブロック図である。液晶表示装置は、第1の実施形態と同様に、フレーム周波数変換部1、ROM3、電極駆動部4、液晶パネル5、同期抽出部7、メインマイコン8、光源駆動部9、バックライト10、メモリ11、モニタマイコン12、温度センサ13、受光部14、及びエリア分割部15を備え、さらに、ガンマ補正部16を備えている。なお、同じ符号が付された部分について繰り返しの説明は省略するものとする。
bra=(brb/255)1/γ・255 …式(2)
しかし、上記式(2)の計算を全ての画素に対して行うのは非効率的であるため、例えば、γ=2.2の場合について、上記式(2)の計算を予め行っておき、この計算結果を図11に示すようなLUTとして格納しておくことで、効率的に処理を行うことができる。なお、以下の説明では液晶表示装置(液晶パネル5)に予め設定されているガンマ設定値を2.2とする。
Claims (19)
- 入力映像信号を表示する液晶パネルと、該液晶パネルを照射する光源と、該光源の発光輝度を制御する光源輝度制御部とを備えた液晶表示装置であって、
該液晶表示装置内の温度を検出する温度検出部と、前記液晶パネルの1垂直表示期間経過後に、前記液晶パネルの透過率を前記入力映像信号の定める透過率に到達させるための強調変換パラメータを求め、該強調変換パラメータに基づいて前記液晶パネルへの印加電圧信号を出力する強調変換部と、前記光源の発光輝度が変化したときに、前記温度検出部で検出された温度に対応する前記液晶パネルのパネル表面温度を前記変化した発光輝度に基づいて補正するパネル温度補正部とを備え、
前記強調変換部は、前記パネル温度補正部により補正されたパネル表面温度に基づいて、前記強調変換パラメータを可変制御することを特徴とする液晶表示装置。 - 請求項1に記載の液晶表示装置において、前記光源が最大発光輝度にあるときの前記温度検出部で検出される温度と前記液晶パネルのパネル表面温度との第1の相関データと、前記光源の発光輝度と前記液晶パネルの最大発光輝度でのパネル表面温度に対する補正値との第2の相関データとを記憶したメモリを備え、前記パネル温度補正部は、前記光源の発光輝度が変化したときに、前記第1の相関データに基づいて、前記温度検出部で検出された温度に対応する前記液晶パネルの最大発光輝度でのパネル表面温度を求め、該パネル表面温度に対する前記発光輝度に基づく補正は、前記第2の相関データに基づいて行われることを特徴とする液晶表示装置。
- 請求項1に記載の液晶表示装置において、前記光源の各発光輝度毎に前記温度検出部で検出される温度と前記液晶パネルのパネル表面温度との相関データを記憶したメモリを備え、前記パネル温度補正部は、前記光源の発光輝度が変化したときに、前記相関データに基づいて、前記温度検出部で検出された温度に対応する前記液晶パネルのパネル表面温度を補正することを特徴とする液晶表示装置。
- 請求項1~3のいずれか1項に記載の液晶表示装置において、前記光源の発光輝度が変化したときに、前記温度検出部で検出される温度が変化しないと判定した場合に、前記パネル温度補正部は、前記補正を行うことを特徴とする液晶表示装置。
- 請求項1~4のいずれか1項に記載の液晶表示装置において、前記液晶パネルを複数のエリアに分割するエリア分割部を備え、前記パネル温度補正部は、前記液晶パネルを分割した各エリア毎のパネル表面温度を、前記変化した発光輝度に基づいて補正し、前記強調変換部は、前記パネル温度補正部により補正されたパネル表面温度に基づいて、前記液晶パネルの各エリア毎に前記強調変換パラメータを可変制御することを特徴とする液晶表示装置。
- 請求項5に記載の液晶表示装置において、前記温度検出部は、前記複数のエリアの数よりも少ない数の温度計測点を有し、該温度計測点の温度に基づいて、各エリアの周囲温度を予測することを特徴とする液晶表示装置。
- 請求項5に記載の液晶表示装置において、前記温度検出部は、前記複数のエリアの数と同じ数の温度計測点を有し、該温度計測点の温度を、各エリアの周囲温度とすることを特徴とする液晶表示装置。
- 入力映像信号を表示する液晶パネルと、該液晶パネルを照射する光源と、該光源の発光輝度を制御する光源輝度制御部とを備えた液晶表示装置であって、
該液晶表示装置内の温度を検出する温度検出部と、前記入力映像信号にガンマ補正を行うガンマ補正部と、前記光源の発光輝度が変化したときに、前記温度検出部で検出された温度に対応する前記液晶パネルのパネル表面温度を前記変化した発光輝度に基づいて補正するパネル温度補正部とを備え、
前記ガンマ補正部は、前記パネル温度補正部により補正されたパネル表面温度に対応するガンマ値を算出し、該算出したガンマ値に従って前記入力映像信号の階調値を変換して出力することを特徴とする液晶表示装置。 - 請求項8に記載の液晶表示装置において、前記光源が最大発光輝度にあるときの前記温度検出部で検出される温度と前記液晶パネルのパネル表面温度との第1の相関データと、前記光源の発光輝度と前記液晶パネルの最大発光輝度でのパネル表面温度に対する補正値との第2の相関データとを記憶したメモリを備え、前記パネル温度補正部は、前記光源の発光輝度が変化したときに、前記第1の相関データに基づいて、前記温度検出部で検出された温度に対応する前記液晶パネルの最大発光輝度でのパネル表面温度を求め、該パネル表面温度に対する前記発光輝度に基づく補正は、前記第2の相関データに基づいて行われることを特徴とする液晶表示装置。
- 請求項8に記載の液晶表示装置において、前記光源の各発光輝度毎に前記温度検出部で検出される温度と前記液晶パネルのパネル表面温度との相関データを記憶したメモリを備え、前記パネル温度補正部は、前記光源の発光輝度が変化したときに、前記相関データに基づいて、前記温度検出部で検出された温度に対応する前記液晶パネルのパネル表面温度を補正することを特徴とする液晶表示装置。
- 請求項9又は10に記載の液晶表示装置において、前記ガンマ補正部は、前記液晶パネルの最大発光輝度でのパネル表面温度と、前記液晶表示装置に予め設定されているガンマ設定値に対する補正値との第3の相関データに基づいて、前記パネル温度補正部により補正されたパネル表面温度に対応するガンマ値を算出することを特徴とする液晶表示装置。
- 請求項8~11のいずれか1項に記載の液晶表示装置において、前記光源の発光輝度がユーザの操作入力により変化したときに、前記ガンマ補正部で算出されたガンマ値と前記液晶表示装置に予め設定されているガンマ設定値とが異なると判定した場合に、前記光源の発光輝度の変化と同時に、前記ガンマ設定値から前記算出したガンマ値へ変化させることを特徴とする液晶表示装置。
- 請求項8~11のいずれか1項に記載の液晶表示装置において、前記光源の発光輝度が周囲の明るさの変化に応じて自動的に変化したときに、前記ガンマ補正部で算出されたガンマ値と前記液晶表示装置に予め設定されているガンマ設定値とが異なると判定した場合に、前記ガンマ設定値から前記算出したガンマ値へ徐々に変化させることを特徴とする液晶表示装置。
- 請求項8~13のいずれか1項に記載の液晶表示装置において、前記光源の発光輝度が変化したときに、前記温度検出部で検出される温度が所定値以上変化しないと判定した場合に、前記パネル温度補正部は、前記温度検出部で検出された温度に対応する前記液晶パネルのパネル表面温度を前記発光輝度に基づいて補正することを特徴とする液晶表示装置。
- 請求項8~14のいずれか1項に記載の液晶表示装置において、前記ガンマ補正部は、前記パネル温度補正部により補正されたパネル表面温度に対応するガンマ値を、白、赤、緑、青毎に算出し、前記白のガンマ値と前記緑のガンマ値とが等しいと判定された場合、前記赤及び青それぞれのガンマ値と前記緑のガンマ値とが等しいか否かを判定し、前記赤及び青それぞれのガンマ値と前記緑のガンマ値とが等しくないと判定された場合、前記赤及び青それぞれのガンマ値を、前記緑のガンマ値になるように調整することを特徴とする液晶表示装置。
- 請求項8~14のいずれか1項に記載の液晶表示装置において、前記液晶パネルを複数のエリアに分割するエリア分割部を備え、前記パネル温度補正部は、前記液晶パネルを分割した各エリア毎のパネル表面温度を、前記変化した発光輝度に基づいて補正し、前記ガンマ補正部は、前記パネル温度補正部により補正されたパネル表面温度に基づいて、前記液晶パネルの各エリア毎にガンマ値を算出し、該算出したガンマ値に従って前記入力映像信号の階調値を各エリア毎に変換して出力することを特徴とする液晶表示装置。
- 請求項16に記載の液晶表示装置において、前記温度検出部は、前記複数のエリアの数よりも少ない数の温度計測点を有し、該温度計測点の温度に基づいて、各エリアの周囲温度を予測することを特徴とする液晶表示装置。
- 請求項16に記載の液晶表示装置において、前記温度検出部は、前記複数のエリアの数と同じ数の温度計測点を有し、該温度計測点の温度を、各エリアの周囲温度とすることを特徴とする液晶表示装置。
- 請求項16~18のいずれか1項に記載の液晶表示装置において、前記ガンマ補正部は、前記パネル温度補正部により補正されたパネル表面温度に対応するガンマ値を、各エリアについて、白、赤、緑、青毎に算出し、前記白のガンマ値と前記緑のガンマ値とが等しいと判定された場合、前記赤及び青それぞれのガンマ値と前記緑のガンマ値とが等しいか否かを各エリア毎に判定し、前記赤及び青それぞれのガンマ値と前記緑のガンマ値とが等しくないと判定された場合、各エリア毎に、前記赤及び青それぞれのガンマ値を、前記緑のガンマ値になるように調整することを特徴とする液晶表示装置。
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Also Published As
Publication number | Publication date |
---|---|
US8553176B2 (en) | 2013-10-08 |
JP5214809B2 (ja) | 2013-06-19 |
US20120212520A1 (en) | 2012-08-23 |
JPWO2011043290A1 (ja) | 2013-03-04 |
EP2487675A4 (en) | 2013-03-06 |
CN102549649A (zh) | 2012-07-04 |
CN102549649B (zh) | 2014-10-15 |
RU2012115463A (ru) | 2013-11-20 |
MX2012004038A (es) | 2012-05-22 |
EP2487675A1 (en) | 2012-08-15 |
US20130106924A1 (en) | 2013-05-02 |
US8363180B2 (en) | 2013-01-29 |
JP2013148912A (ja) | 2013-08-01 |
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