JP4348517B2 - Panel display television adjustment system, panel display television adjustment method, and panel display television. - Google Patents

Description

The present invention relates to a panel display television adjustment system, a panel display television adjustment method for a panel display television capable of performing gamma correction in particular, and a panel display television as an object thereof.

Conventionally, this type of panel display television stores a correction table indicating the correspondence of output gradation after gamma correction corresponding to each input gradation value in a memory in advance, and dynamically performs gamma correction based on the correction table. One that adjusts the maximum value, brightness, and contrast is known (for example, see Patent Document 1).
According to such a configuration, it is possible to perform appropriate gamma correction based on the correction table. In this configuration, the correction table corresponding to the representative value of the input gradation is stored in advance, and the correction table corresponding to the input gradation at all stages is generated by plotting the correction table and connecting them with a polygonal line. (See FIG. 2 of Patent Document 1).
JP 2001-309207 A

In the conventional panel display television described above, the gamma characteristic may be different for each panel display television set due to manufacturing errors of the panel display panel, etc., and the appearance of the image is different for each panel display television set. There was a case. In this case, even if the dynamic maximum value, brightness, and contrast can be adjusted, the correction table itself cannot be optimized, and there is a problem that it cannot be fundamentally solved.
In addition, when trying to optimize the correction table for each panel display television set, the output tone value after gamma correction is optimized for each representative value of the input tone for each panel display television set. In addition, it is necessary to store a plurality of correction tables in a memory in advance, and select a table suitable for each panel display television set from among them.

However, in the former, since it is necessary to calculate the optimum output tone value after gamma correction for each representative value of the input tone and rewrite the correction table, data transmission between the adjusting device and the panel display television There was a problem that it took time. In the latter, since it is necessary to store a plurality of the correction tables in a memory, there is a problem that a large-capacity memory is required.
The present invention has been made in view of the above problems, and is a panel display television adjustment system capable of efficiently optimizing a gamma correction table for each panel display television set while saving memory capacity. Another object is to provide a panel display television adjustment method and a panel display television.

In order to achieve the above object, the invention according to claim 1 generates video data expressed by digital gradation values for each of a plurality of pixels constituting a screen based on an input video signal, and has non-linear characteristics. A correction table indicating the correspondence between input gradation values and output gradation values for compensation and display on the display panel is stored in the EEPROM, and the video data is converted with reference to the correction table to perform gamma correction. A panel display television adjustment system comprising: a panel display television to perform, and an adjustment device for setting a parameter for compensating for the nonlinear characteristic in the panel display television,
The above-mentioned panel display television has a low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and the inflection point scale. The correction consisting of a predetermined correction curve passing through the inflection point based on the parameter corresponding to the high gradation γ value for generating a correction curve using a gamma correction curve in a gradation range larger than the tone value A correction table generating means for generating a table, a parameter storage means for inputting the parameters set by the adjusting device and storing them in the EEPROM, and generating the correction table based on the stored parameters Correction table updating means for storing the correction table in the EEPROM, and the adjusting device is provided in the panel display television. And parameter setting means for setting the parameters stored in the parameter storage means delivers outputs the gray reference video signal while changing the gradation value in the range of all gradation values for the panel display television Video signal output means;
It is possible to measure the brightness of the screen displayed by the panel display television based on the output reference video signal, and the correspondence between the same gradation value and the same brightness according to the change of the same gradation value A measuring unit that measures the image, and whether or not the correspondence between the gradation value and the brightness is linear within an allowable range based on a measurement result by the measuring unit, and the allowable range If it is not linear, a parameter setting control means for increasing / decreasing the value of the parameter and executing setting by the parameter setting means, output by the video signal output means, and measurement by the measuring means is provided.

  In the invention of claim 1 configured as described above, the panel display television can generate video data expressed by digital gradation values for each of a plurality of pixels constituting the screen based on an input video signal. Is possible. Gamma correction is performed by converting the video data generated with reference to the correction table stored in the EEPROM. That is, since the correction table shows the correspondence between the input gradation value and the output gradation value that can compensate for the nonlinear characteristic, it is possible to ensure linearity in the image displayed on the display panel. The adjusting device adjusts and sets a parameter for compensating for the nonlinear characteristic of an image displayed on the display panel. That is, the gamma correction in the panel display television can be properly performed by the adjustment device appropriately adjusting the parameter.

The panel display television is provided with correction table generation means, and the correction table generation means generates the correction table including a predetermined correction curve. This correction curve is defined more inflection point gradation value and the low gradation γ value and high gradation γ value corresponding to the inflection point, it passes through the inflection point. The correction curve is generated from a gamma correction curve based on the low gradation γ value in a gradation range smaller than the inflection point gradation value, and in the gradation range larger than the inflection point gradation value. It is generated from a gamma correction curve with high gradation γ values. That is, the correction table generating means can generate the correction table from the parameter and the gamma correction curve composed of the inflection point gradation value, the low gradation γ value, and the high gradation γ value. .

  The parameters used for generating the correction table are set by the adjusting device and stored in an EEPROM provided in the panel display television by the parameter storage means. The correction table generated based on the parameters by the correction table updating means is also stored in the EEPROM. Accordingly, when the correction table is updated in the EEPROM, the gamma correction can be performed with reference to the updated correction table. In other words, the parameters set by the adjusting device can be reflected in the gamma correction performed thereafter.

  On the other hand, the adjusting device includes parameter setting means, sets the parameters adjusted by the parameter setting means, and outputs them to the parameter storage means in the panel display television. At this time, the data output from the adjusting device to the panel display television need only be the parameters. The adjusting device includes a video signal output means, which outputs a gray reference video signal to the panel display television while changing the gradation values in the range of all gradation values. In other words, the gradation value of each channel of red, green, and blue is kept uniform, and the gradation value is changed in the range of all gradation values and output. Therefore, since the contribution ratio to the luminance of each channel can be equalized, the luminance of each channel can be evaluated simultaneously. When a reference video signal is output to the panel display television, an image corresponding to the display panel of the panel display television is displayed. The measuring means can measure the luminance of the video screen, and can measure the correspondence between the gradation value of the reference video signal and the luminance according to the change of the gradation value. . Further, since the gradation value is changed in the range of all gradation values, the correspondence relationship of the luminance with respect to all gradations can be measured.

  The correspondence relationship between the measured gradation value of the reference video signal and the luminance corresponding to the change in the gradation value is analyzed by the parameter setting control means. That is, it is determined whether or not the gamma correction based on the parameter compensates for the nonlinear characteristic of an image displayed on the display panel. In determining whether or not to compensate for this nonlinear characteristic, an allowable predetermined range is set, and it is determined whether or not linearity is realized within the same range. If the linearity is not realized within the above range, the value of the parameter is increased or decreased. That is, the value of the parameter is increased or decreased to change the gamma correction characteristic. When the value of the parameter is increased or decreased, setting by the parameter setting unit, output by the video signal output unit, and measurement by the measuring unit are executed in order to confirm the validity of the increase or decrease. By repeating the above processing until the linearity is realized, the parameter can be adjusted so that the nonlinear characteristic of the video displayed on the display panel can be compensated.

Furthermore, the invention according to claim 2 generates video data expressed by digital gradation values for each of a plurality of pixels constituting the screen based on an input video signal, and compensates for nonlinear characteristics to display a display panel. A panel display that stores a correction table showing the correspondence between input gradation values and output gradation values for display above in a non-volatile memory, converts the video data with reference to the correction table, and performs gamma correction A panel display television adjustment system comprising a television and an adjustment device for setting a parameter for compensating for the nonlinear characteristic in the panel display television,
The above-mentioned panel display television has a low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and the inflection point scale. The correction consisting of a predetermined correction curve passing through the inflection point based on the parameter corresponding to the high gradation γ value for generating a correction curve using a gamma correction curve in a gradation range larger than the tone value A correction table generating means for generating a table; a parameter storage means for inputting the parameters set by the adjusting device and storing them in a nonvolatile memory; and generating the correction table based on the stored parameters. Correction table updating means for storing the generated correction table in the non-volatile memory, and the adjustment device includes the panel display television. A video signal output means for outputting the video signal while changing the gradation value in a predetermined range and parameter setting means for setting the parameters stored in the parameter storage means, with respect to the panel display television in, The brightness of the screen displayed by the panel display television can be measured based on the output video signal, and the correspondence between the same gradation value and the same brightness according to the change of the same gradation value can be measured. It is determined whether or not the correspondence between the gradation value and the luminance is within a predetermined allowable range based on the measurement unit to be measured and the measurement result by the measurement unit. A parameter setting control means for increasing / decreasing the value of the parameter and executing setting by the parameter setting means, output by the video signal output means, and measurement by the measuring means; Are you.

  In the invention of claim 2 configured as described above, the panel display television may generate video data expressed by digital gradation values for each of a plurality of pixels constituting the screen based on an input video signal. Is possible. Gamma correction is performed by converting the video data generated with reference to the correction table stored in the non-volatile memory. That is, since the correction table shows the correspondence between the input gradation value and the output gradation value that can compensate for the nonlinear characteristic, it is possible to ensure linearity in the image displayed on the display panel. The adjusting device adjusts and sets a parameter for compensating for the nonlinear characteristic of an image displayed on the display panel. That is, the gamma correction in the panel display television can be properly performed by the adjustment device appropriately adjusting the parameter.

The panel display television is provided with correction table generation means, and the correction table generation means generates the correction table including a predetermined correction curve. This correction curve is defined more inflection point gradation value and the low gradation γ value and high gradation γ value corresponding to the inflection point, it passes through the inflection point. The correction curve is generated from a gamma correction curve based on the low gradation γ value in a gradation range smaller than the inflection point gradation value, and in the gradation range larger than the inflection point gradation value. It is generated from a gamma correction curve with high gradation γ values. That is, the correction table generating means, that upper SL low gradation γ value and the composed of the high gradation γ value the parameter and the inflection point gradation value and from the above gamma correction curve to generate the correction table it can.

  The parameters used for generating the correction table are set by the adjusting device and stored in a nonvolatile memory provided in the panel display television by the parameter storage means. Further, the correction table generated based on the parameters by the correction table updating means is also stored in the nonvolatile memory. Accordingly, when the correction table is updated in the nonvolatile memory, the gamma correction can be performed with reference to the updated correction table. In other words, the parameters set by the adjusting device can be reflected in the gamma correction performed thereafter.

  On the other hand, the adjusting device includes parameter setting means, sets the parameters adjusted by the parameter setting means, and outputs them to the parameter storage means in the panel display television. The adjusting device includes a video signal output means, and the video signal output means outputs a video signal to the panel display television while changing a gradation value within a predetermined gradation value range. When a reference video signal is output to the panel display television, an image corresponding to the display panel of the panel display television is displayed. The measuring means can measure the luminance of the video screen, and measures the correspondence between the gradation value of the reference video signal and the luminance according to the change of the gradation value in a predetermined range. can do.

The correspondence relationship between the measured gradation value of the reference video signal and the luminance corresponding to the change in the gradation value is analyzed by the parameter setting control means. That is, it is determined whether or not the gamma correction based on the parameter compensates for the nonlinear characteristic of an image displayed on the display panel. In determining whether or not to compensate for this nonlinear characteristic, an allowable predetermined range is set, and it is determined whether or not the actual luminance falls within this range. Then, if there Tei becomes within a predetermined range actual luminance is acceptable, increase or decrease the value of the parameter. That is, the value of the parameter is increased or decreased to change the gamma correction characteristic. When the value of the parameter is increased or decreased, setting by the parameter setting unit, output by the video signal output unit, and measurement by the measuring unit are executed in order to confirm the validity of the increase or decrease. By repeating the above processing until the linearity is realized, the parameter can be adjusted so that the nonlinear characteristic of the video displayed on the display panel can be compensated.

  According to a third aspect of the present invention, is the parameter setting control means linear in a predetermined range in which a correspondence relationship between the gradation value and the luminance is allowed based on a measurement result by the measurement means? A parameter for determining whether or not the value is not linear within an allowable range and executing the setting by the parameter setting means, the output by the video signal output means, and the measurement by the measuring means by increasing or decreasing the value of the parameter And a setting control means.

  In the invention of claim 3 configured as described above, the parameter setting control means determines whether or not the correspondence relationship between the gradation value and the luminance is linear within an allowable range. If the correspondence between the gradation value and the luminance is within a predetermined allowable range, it can be determined that the gamma correction is properly performed, and the correspondence between the gradation value and the luminance is allowed. If it is out of the predetermined range, it can be determined that the gamma correction is not properly performed. If it is determined that the gamma correction is not properly performed, the parameter is increased or decreased. That is, the gamma correction correction characteristic is corrected by increasing or decreasing the parameter.

Furthermore, the invention according to claim 4 is configured such that the video signal output means outputs a gray reference video signal while changing a gradation value within a predetermined range with respect to the panel display television.
In the invention according to claim 4 configured as described above, the video signal output means outputs a gray reference video signal to the panel display television while changing a gray scale value in a range of all gray scale values. . That is, the gradation value of each channel of red, green, and blue is kept uniform and the gradation value is changed within a predetermined gradation value range and output. Therefore, since the contribution ratio to the luminance of each channel can be equalized, the luminance of each channel can be evaluated simultaneously.

According to a fifth aspect of the present invention, the video signal output means outputs a video signal while changing the gradation value in the range of all gradation values with respect to the panel display television.
In the invention of claim 5 configured as described above, the video signal output from the video signal output means to the panel display television can be changed in gradation value in the range of all gradation values. That is, it is possible to confirm whether or not the non-linear characteristic of the image displayed on the display panel is compensated by gamma correction in all gradations.

  Further, as in the invention according to claim 6, the same effect and effect can be obtained by the panel display television adjustment method for setting and outputting the parameter to the panel display television.

Furthermore, the invention according to claim 7 generates video data expressed by digital gradation values for each of a plurality of pixels constituting the screen based on an input video signal, and compensates for nonlinear characteristics to display a display panel. A panel display that stores a correction table showing the correspondence between input gradation values and output gradation values for display above in a non-volatile memory, converts the video data with reference to the correction table, and performs gamma correction A television,
A low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and a gradation range larger than the inflection point gradation value A correction table generating means for generating the correction table including a predetermined correction curve passing through the inflection point based on a parameter including a high gradation γ value for generating a correction curve using a gamma correction curve in A parameter storage means for inputting the parameters adjusted by an adjustment device connected to the outside and storing the parameters in a nonvolatile memory; and generating the correction table based on the stored parameters and generating the correction table A panel display television, comprising: a correction table updating means stored in the nonvolatile memory.

In the invention of claim 7 configured as described above, the correction table includes the parameter including the low gradation γ value and the high gradation γ value, the inflection point gradation value, and the gamma correction curve. Since it can be generated, the adjusted correction table can be obtained by receiving the parameter adjusted by the adjusting device.

According to the first, second, sixth, and seventh aspects of the invention, the gamma correction table itself can be optimized, so that different gamma characteristics are uniform for each body of the panel display television. Adjustment is possible.
In the invention according to claim 3, it can be determined whether or not the gamma correction compensates for the non-linearity of the display panel.

In the invention according to claim 4, gamma correction can be simultaneously evaluated for each of the red, green, and blue channels.
In the invention according to claim 5, it is possible to determine whether or not the gamma correction compensates for the non-linearity of the display panel in all gradations.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of panel display television adjustment system:
(2) About the gamma correction table:
(3) Configuration of adjustment computer:
(4) Explanation of adjustment process and panel display television adjustment method:

(1) Configuration of panel display television adjustment system:
FIG. 1 is a system configuration diagram showing a schematic configuration of an example of a panel display television adjustment system 10 according to an embodiment of the present invention, and FIG. 3 shows a configuration of a liquid crystal television (TV) 100 as a panel display television. FIG.

  The liquid crystal television adjusting device of the present invention comprises a color analyzer 30 and a personal computer (PC) 40 which is an adjusting computer. The system 10 includes the liquid crystal television adjustment device and the TV 100. The TV 100 to be adjusted is connected to the PC 40 via a predetermined signal cable 29 and also connected to the PC 40 via another predetermined signal cable 49.

  FIG. 2 is a block diagram showing the configuration of the color analyzer 30. The color analyzer 30 includes, as an optical system, a CCD image pickup device 31, a controller 32a to which the CCD image pickup device 31 is connected, a lens control system 32b, and the like. Further, as a control system, an analog / digital conversion circuit (A) connected to a microcomputer 33a and a controller 32a having a CPU, ROM, RAM, I / O port and the like connected to an internal bus and connected to a CCD image pickup device 31. / D conversion circuit) 33b, an interface (I / F) 33c to which a predetermined signal cable 39 is connected, and the like are connected to the system bus 30a. A controller 32a is connected to the I / O port of the microcomputer 33a, and the microcomputer 33a reads a digital luminance value (measured value) from the A / D conversion circuit 33b via the bus 30a while controlling the operation of the controller 32a. It is possible to output from the I / F 33c to the outside. A PC 40 is connected to the I / F 33c via a cable 39.

  With the above configuration, when the color analyzer 30 having the CCD image pickup device receives a signal indicating an image pickup instruction from the PC 40, the color analyzer 30 picks up an image of the display screen 199 of the TV 100, and the CCD image pickup device 31 corresponds to the luminance for each CCD image pickup device. The voltage is detected and converted into a digital voltage value (256 gradations of 0 to 255) corresponding to the voltage detected by the A / D conversion circuit 33b, and the converted voltage value is detected as a luminance value. In addition, the gradation value output from the PC 40 to the TV 100 is acquired via the I / F 33c and the cable 39, and the correspondence between the luminance value and the gradation value output from the PC 40 to the TV 100 is determined. ing. Then, data indicating the correspondence between the luminance value and the gradation value output from the PC 40 to the TV 100 is output to the PC 40 via the I / F 33 c and the cable 39. The measuring means referred to in the present invention is constituted by the color analyzer 30.

  FIG. 3 is a block diagram showing a configuration of a liquid crystal display television (TV) 100 as a panel display television. In the TV 100, the power supply device 190 includes a main body unit 101, an inverter 186, a liquid crystal module (liquid crystal display unit) 180, and the like. The power supply device 190 supplies a predetermined direct current voltage to the main body 101, the inverter 186, and the liquid crystal module (liquid crystal display unit) 180. The inverter 186 receives the DC voltage from the power supply device 190, generates a high voltage, and supplies it to the backlight 185 of the liquid crystal module 180.

  The main body 101 includes the respective units 103, 110, 111, 112, 120, 121, 122, 123, 130, 170, CLK1, CLK2, and the like shown in FIG. The IIC bus 102 including the clock line SCL and the data line SDA has an IIC bus data port 103, a microcomputer 110, an EEPROM (nonvolatile memory capable of rewriting stored data) 112, and a known tuner IC. The tuner circuit 120 and the I / F 164 of the video signal processing unit 130 are connected. These circuits transmit / receive serial data to / from each other via the bus 102. The tuner circuit 120 is operated by a control based on a signal input from the microcomputer 110 directly connected via another signal line via the signal line.

  The video signal processing unit 130 that operates by being supplied with a clock signal from the oscillation circuit CLK2 has an IC as a main part, and is composed of the respective units 140, 150, 161 to 164, and the like. Further, the RGB signal generation unit 140 is configured by the units 141 to 145 and the RGB signal processing unit 150 is configured by the units 151 to 155 and the like.

  The microcomputer 110 is directly connected to the oscillation circuit CLK1, the operation panel 111, and a remote control signal light receiving unit (not shown), and can input data corresponding to an operation input to the operation panel 111 or the like from the operation panel 111 or the like. . The microcomputer 110 also includes a CPU, ROM, RAM, a plurality of I / O ports, a timer circuit (not shown), and the like connected to an internal bus. The microcomputer 110 controls internal circuits written in the ROM or the EEPROM 112. The function as a TV is realized by controlling the entire TV according to the program.

  The EEPROM 112 stores a gamma correction table (correction table) 113 that represents the correspondence between input gradation values and output gradation values for reference when performing gamma correction that compensates for the non-linear characteristics of display of the liquid crystal module 180. ing. Further, a function 114 of the gamma correction curve necessary for generating the correction table and its parameter 115 are stored.

  The correction table generation circuit 170 reads the function 114 of the gamma correction curve and the parameter 115 of the function 114 from the EEPROM 112, creates a gamma correction table 113 based on these functions, and stores it in the EEPROM 112.

  The tuner circuit 120 is a known circuit for analog television whose main part is an IC. An analog television signal (a kind of video signal) according to a predetermined broadcasting system is input from the antenna 121 to generate an intermediate frequency signal. It is possible to create and output. The predetermined broadcasting system includes a PAL system, a SECAM system, an NTSC system, etc., and the tuner circuit may be a circuit that inputs a TV signal of a plurality of types of broadcasting systems and generates an intermediate frequency signal. The circuit 120 incorporates a so-called frequency synthesizer type tuner, and includes a high-frequency amplifier circuit, a local oscillation circuit, a mixing circuit, and the like (not shown). Of course, a voltage synthesizer system or the like may be used.

  The main part of the switch circuit 122 is an IC, to which the microcomputer 110, the tuner circuit 120, and the composite video input terminal 123 are connected. The switch circuit 122 selectively inputs an intermediate frequency signal from the tuner circuit 120 and an analog composite video signal (a type of video signal) from the terminal 123 in accordance with a selection instruction input from the microcomputer 110, and outputs a synchronization signal. The separated signal is output to the synchronization signal control circuit 161, and the video signal from which the synchronization signal is separated is output to the A / D conversion circuit 141.

The synchronization signal control circuit 161 receives the synchronization signal and performs control to synchronize the signal in the video signal processing unit 130 in synchronization with the clock signal of the oscillation circuit CLK2. The video timing circuit 162 generates a video timing signal for matching the timing of the generated YUV signal (the signal composed of the luminance signal Y and the color difference signals RY and BY) in accordance with the instruction of the circuit 161, and the chroma decoder circuit 143. To the panel timing circuit 163. The panel timing circuit 163 generates a panel timing signal for matching the timing of the generated RGB signal (a signal composed of an R signal, a G signal, and a B signal) and outputs the panel timing signal to the RGB signal processing unit 150.
The RGB signal generation unit 140 is connected to the I / F 164 and performs predetermined processing in accordance with an instruction from the microcomputer 110.

  The A / D conversion circuit 141 inputs the video signal from which the synchronization signal is separated, performs A / D conversion, and 256-step digital gradation corresponding to the voltage between the white level and the black level of the video signal. Convert to value. Then, a digital signal having a digital gradation value is output to the YC separation circuit 142. The YC separation circuit 142 receives this digital signal, separates it into a luminance signal Y and a carrier color signal C, and outputs it to the chroma decoder circuit 143. The chroma decoder circuit 143 receives the luminance signal Y and the carrier color signal C, generates a YUV signal corresponding to the luminance signal Y and the carrier color signal C, matches the timing with the video timing signal, and adjusts the image quality adjustment circuit 144. Output for. The image quality adjustment circuit 144 receives the YUV signal, performs color adjustment such as contrast adjustment, TINT adjustment, brightness adjustment, and skin color correction, black and white expansion adjustment, delay adjustment, horizontal sharpness adjustment, and the like. The signal is output to the matrix circuit 145. The matrix circuit 145 receives the YUV signal after the adjustment process, generates a RGB signal which is a three-color signal for each of the three primary colors by combining the luminance signal Y and the color difference signals RY and BY, and the pixel number conversion circuit 151. Output for. This RGB signal is video data that expresses an image with digital gradation values for a large number (multiple) of pixels for each color. The larger the gradation value, the brighter the image (the higher the luminance), and the smaller the gradation value. The image becomes darker (the brightness decreases).

  The RGB signal processing unit 150 is connected to the I / F 164 and performs predetermined processing in accordance with an instruction from the microcomputer 110. A memory 155 including a RAM is connected to each of the units 151 to 154, holds image quality adjustment data such as a correction table for gamma correction, and stores video data including RGB signals for one screen.

  A pixel number conversion circuit 151, also called a scaler, inputs RGB signals, performs a predetermined scaling process for converting the number of pixels according to the number of pixels of the liquid crystal panels 182 to 184, matches the timing with the panel timing signal, The RGB signal after the number conversion is written in the memory 155. In the present embodiment, the number of pixels of the liquid crystal panels 182 to 184 will be described as being 640 × 480 pixels, but may be 1024 × 768 pixels or the like. The RGB signal written in the memory 155 is video data that expresses video with digital gradation values for each 640 × 480 pixels for each color, and the gradation values are assumed to be 256 gradations from 0 to 255. explain.

  The image quality adjustment circuit 152 sequentially refers to the gradation value of each pixel for each color from the memory 155, and performs contour correction, OSD signal superimposition, and saturation correction for the gradation value constituting the RGB signal after the number of pixels conversion. , Etc. are adjusted.

  The γ correction circuit 153 performs gamma correction on the RGB signal after the adjustment process, and compensates for the gamma characteristic of the display of the liquid crystal module 180. When the power of the TV is turned on, the microcomputer 110 reads the correction table 113 from the EEPROM 112 and stores it in the memory 155 via the I / F 164. The γ correction circuit 153 refers to the correction table held in the memory 155 in the power-on state, and acquires the output gradation value corresponding to the input gradation value for each pixel of each color of the RGB signal from the correction table. Then, gamma correction for generating video data after gamma correction is performed by replacing the input gradation value with the acquired output gradation value.

  The luminance / contrast adjustment circuit 154 performs luminance adjustment and contrast adjustment processing on the video data after the gamma correction expressed by the gradation value for each color pixel stored in the memory 155, and Output to the control circuit 181.

The control circuit 181 is an electronic circuit that performs a screen display control driving process, and drives the R liquid crystal panel 182, the G liquid crystal panel, and the B liquid crystal panel 184 for each color from the video data that has been subjected to gamma correction. Is generated. The backlight 185 is turned on when a high voltage is supplied from the inverter 186, and the generated light is transmitted through the liquid crystal panels 182 to 184 from the back to the front. Accordingly, the liquid crystal module 180 displays a video corresponding to the video data from the screen 199, that is, a video corresponding to the video signal.

In the TV to which the reference signal is input, video data corresponding to the reference signal is generated, gamma correction is performed on the video data, and a reference display screen corresponding to the reference signal is displayed from the screen 199.

  An I / O port 24 connected to the signal switching unit 23 may be provided. If the I / O port 24 is connected to the I / O port 41g of the PC 40, the reference signal for the composite video signal and the reference signal for the component video signal can be switched by input from the PC. Become.

(2) About the gamma correction table:
The relationship between the correction table 113, the gamma correction curve function 114, and the parameter 115 of the function 114 will be described in detail below. FIG. 4 schematically shows the correction table. The correction table D1 is composed of numerical data composed of a plurality of output gradation values after gamma correction corresponding to the input gradation values of all stages from 0 to 255, respectively. In the graph G1 on the right side of the figure, the horizontal axis represents the input gradation value, and the vertical axis represents the output gradation value after gamma correction.

A correction table D1 composed of a plurality of output tone values after gamma correction corresponding to the input tone values can be shown as a single curve in the graph G1, and this curve is shown as a γ curve C. However, strictly speaking, the γ curve C is a discontinuous digital gradation value, so it is approximated to a continuous curve. Whereas the input tone value is γ curve C in I _t is less than the low gray scale region has a curved shape that is convex to the output tone value side of the gamma correction, the input tone values I _t In a larger high gradation region, the γ curve C has a curved shape that is convex toward the input gradation value side. That, gamma curve C at the point where the input tone value is I _t is inflected. Hereinafter referred to as inflection point gradation value input gradation value I _t. Further, the output tone value O _t after correction in the input gradation value I _t is equal to the input tone value I _t.

一方、入力階調値がＩ_tより小さい低階調領域においては下記式（２）により、ガンマ補正後の出力階調値Ｏが与えられる。

なお、上記の二式おいて、Ｉは入力階調値を示し、Ｏはガンマ補正後の出力階調値を示し、Ｉ_rは入力階調値の最大値（２５５）を示し、Ｏ_rは補正後の出力階調値の最大値（２５５）を示し、γ₁は低階調γ値を示し、γ₂は高階調γ値を示している。上記の二式において、ガンマ補正後の出力階調値Ｏは、入力階調値の最大値Ｉ_rと出力階調値の最大値Ｏ_rと低階調γ値γ₁と高階調γ値γ₂と変曲点階調値Ｉ_tとを定数パラメータとして有するとともに、入力階調値Ｉを変数として有するガンマ補正曲線の関数として表される。 Here, the relationship between the input tone value and the output tone value after the gamma correction can be expressed by a function 113 of a gamma correction curve stored in the EEPROM 112. The function 113 of the gamma correction curve is composed of, for example, two formulas of the following formula (1) and the following formula (2). In the input tone value I _t is less than the low gray scale region by the following formula (1), the output tone value O after gamma correction is applied.

On the other hand, in the input tone values I _t is less than the low gray scale region by the following formula (2), the output tone value O after gamma correction is applied.

In the above two equations, I represents the input gradation value, O represents the output gradation value after gamma correction, I _r represents the maximum value (255) of the input gradation value, and _Or represents The maximum output gradation value (255) after correction is indicated, γ ₁ indicates a low gradation γ value, and γ ₂ indicates a high gradation γ value. In the two-equations, the output tone value O after gamma correction, the maximum value of the output gradation value and the maximum value I _r of the input tone value O _r and low gradation gamma value gamma ₁ and high gradation gamma value gamma together with a ₂ and the inflection point gradation value I _t as a constant parameter, expressed as a function of the gamma correction curve having the input gradation value I as variables.

In other words, the maximum value maximum value O _r and low gradation gamma value gamma ₁ and high gradation gamma value gamma ₂ of I _r and the output tone value of the input tone values, to obtain the inflection point gradation value I _t If possible, the output tone value O after gamma correction can be uniquely calculated from the input tone value I. In other words, if these parameters are given, the correction table D1 can be generated. Therefore, the maximum value I _r and the maximum value O _r and low gradation gamma value gamma ₁ and high gradation gamma value gamma ₂ and the inflection point gradation value I _t and gamma of the output tone value of the input tone value as a parameter The correction curve function is stored in the EEPROM 112, so that the correction table generation circuit 170 can read the parameter 115 and the gamma correction curve function 114 to generate a gamma correction table. Of course, since the gamma correction table needs to be stored in digital gradation, strictly speaking, the output gradation value O after the gamma correction calculated by the γ function is converted into an integer by rounding up, rounding down, or rounding.

The output tone value O after correction and substituting inflection point gradation value I _t to an input gradation value I in the above formula (1) and the formula (2) is both equal to the input tone value I . That is, the gamma curve C in the low gradation region, gamma curve C in high gradation region is connected at the inflection point gradation value I _t, the output tone value O and the corrected input gradation value I in the connection point Are equal.

Here, the maximum value I _r of the input tone values, the maximum value O _r of the output tone values are all in a single model the same (256 gradations in this embodiment). Therefore, there is no difference between individual aircraft. However, even if it is a single model, individual gamma characteristics may differ due to manufacturing errors of mounted liquid crystal panels and the like. In this case, it is desirable to perform gamma correction suitable for the gamma characteristics of the individual aircraft, and the gamma correction table 113 stored in the EEPROM 112 is also desirably adapted to the gamma characteristics of the individual aircraft. In order to correct the gamma correction table 113 to be adapted to the gamma characteristic of each aircraft, the value of the parameter 115 of the function 114 of the gamma correction curve used to generate the gamma correction table D1 is corrected as follows. That's fine.

In the low gradation region, the curve shape of the γ curve C is determined by the low gradation γ value γ ₁ . The larger the low gradation γ value γ ₁ , the greater the bulge of the γ curve C toward the output gradation value axis after correction. For example, in FIG. 4, the γ curve C given by the low gradation γ value γ ₁ = 2.2 and the low gradation γ value γ ₁ = 2.3 is compared. That is, as the low gradation γ value γ ₁ is larger, the corrected output gradation value with respect to the input gradation value becomes larger. As described above, since the curve shape of the γ curve C is convex toward the corrected output tone value axis in the low tone region, the range of possible values of the low tone γ value γ ₁ is “γ ₁ ≧ 1 ". From the above, when the output gradation after gamma correction in the low gradation area is large (brighter than ideal), the low gradation γ value γ ₁ may be corrected, and the output level after gamma correction may be corrected. When the tone is small (darker than ideal), the low gradation γ value γ ₁ may be increased.

On the other hand, the curve shape of the γ curve C in the high gradation region is determined by the high gradation γ value γ ₂ . The smaller the high gradation γ value γ ₂ , the larger the bulge of the γ curve C toward the input gradation value axis. For example, in FIG. 4, the γ curve C given by the high gradation γ value γ ₂ = 0.45 and the high gradation γ value γ ₂ = 0.43 is compared and shown. That is, the smaller the high gradation γ value γ ₂ , the smaller the output gradation value after correction for the input gradation value. As described above, since the curve shape of the γ curve C is convex toward the input gradation value axis in the high gradation region, the range of values that the high gradation γ value γ ₂ can take is “γ ₂ ≦ 1”. From the above, when the output gradation after gamma correction in the high gradation area is large (brighter than ideal), it is sufficient to correct the high gradation γ value γ _2, and the output gradation after gamma correction is If it is small (darker than ideal), the low gradation γ value γ ₂ may be increased.

As described above, by adjusting the low gradation γ value γ ₁ and the high gradation γ value γ ₂ , it is possible to generate the correction table D1 capable of performing desired gamma correction. Of course, it may also adjust the characteristics of the gamma correction by adjusting the inflection point gradation value I _t, low gradation gamma value gamma ₁ and high gradation gamma value gamma ₂ only an adjustment in the present embodiment By doing so, the correction table is adjusted. The adjustment process of the low gradation γ value γ ₁ and the high gradation γ value γ ₂ as parameters will be described later.

However, the function of the gamma correction curve shown in the above formula (1) and the above formula (2) is adapted to the gamma characteristic of the model of the TV 100 of the present embodiment, and an optimal function is provided for each model of the panel display television. Is set. For example, the possible value of the high gradation γ value γ ₂ with “γ ₂ ≦ 1” may be unlimited, or a function having two or more inflection points may be set.

(4) Configuration of adjustment computer:
As shown in FIG. 5, the PC (adjustment computer) 40 includes a CPU 41a, a ROM 41b, a RAM 41c, a display I / F 41d, a hard disk (HD) 41e having a driver function, an input I / F 41f, and an I / O port. 41g, a communication port 40a, an I / O board 40b, a TVI / F 40c, and the like are connected. As the communication port 40a, for example, an LPT port, an RS-232 port, a COM port, or the like can be used. A display 41d1 is connected to the display I / F 41d, and a keyboard 41f1 and a mouse 41f2 are connected to the input I / F 41f. The IIC data port 103 of the TV 100 is connected to the port 40a via the cable 49, and the color analyzer 30 is connected to the I / O board 40b via the cable 39. A TV terminal 123 is connected to the TVI / F 40 c through a signal cable 29.

  The CPU 41a executes a predetermined control program written in the ROM 41b while using the RAM 41c as a work area. The HD 41e stores an application program (APL) for determining a correction table for gamma correction and storing it in the TV, an APL for generating a reference video signal, and an ideal luminance line (curve). It is read and APL is executed. Based on the above hardware, the PC 40 performs a process for adjusting the parameters for generating the gamma correction table, and performs a process for outputting the adjusted parameters and the reference video signal to the TV 100.

  Various PCs such as a desktop type, a notebook type, and a mobile type can be adopted as the PC 40, but computers other than the PC can also be adopted.

(4) Explanation of adjustment process and panel display television adjustment method:
FIG. 6 shows the flow of adjustment processing of the present system, and the processing of the adjustment computer 40 and the liquid crystal TV 100 is shown by a flowchart. These flows are performed by the CPU 41a of the PC or the microcomputer 110 of the TV. The parameter setting control means referred to in the present invention is composed of a PC 40 that performs the adjustment processing shown in the figure, control units 33a-c, 30a of the color analyzer 30, and a cable 39. It is assumed that the TV image quality adjustment is performed in the final adjustment process at the factory where the TV is manufactured. Here, the function of the gamma correction curve, the correction inflection point gradation value as constant parameter I _t and the default low gradation gamma value gamma ₁ and high gradation gamma value gamma _2, and are generated based on these tables This processing is performed after mounting the EEPROM in which is written on the TV.

When a factory worker turns on the power of the TV 100 to adjust the image quality, the TV reads out a correction table generated from the default low gradation γ value γ ₁ and high gradation γ value γ ₂ from the EEPROM 112 and sets the terminal. The reference signal of the same video signal is received from 123 (step S105). That is, the TV 100 generates video data that represents a video with a digital gradation value for each of a number of pixels from the video signal, and an output gradation corresponding to an input gradation value that constitutes the video data by the γ correction circuit 153. The value is acquired from the correction table 113 in the EEPROM 112, and while maintaining this in the memory 155, the gamma correction circuit 152 performs gamma correction by replacing the input gradation value with the acquired output gradation value. The video data on which the gamma correction has been performed is on standby in a state where it can be output to the liquid crystal module 180.

Note that the operation of the TV 100 so far is also the operation performed in the start-up operation that is executed during normal use. Next, when the PC 40 is connected to the TV 100 and the operator performs a predetermined operation on the PC 40 to start the adjustment flow (step S110), the TV 100 is switched from the normal mode to the factory mode in step S115. In this factory mode, the low gradation γ value γ ₁ and the high gradation γ value γ ₂ stored in the parameter 115 of the EEPROM 112 can be rewritten as required by the adjustment computer 40 and are generated based on these. The correction table 113 can also be rewritten.

  On the other hand, when the adjustment flow is started in step S110 in the PC 40, a reference signal is generated by the APL stored in the HD 41e in step S120, and the reference signal is output to the TV 100 waiting in the signal waiting state. This reference signal includes signals of each channel of red (R), green (G), and blue (B). Here, a gray signal in which the input gradation value of each channel is R = G = B. Is generated and output. In the gray signal, all channels are output as equal gradation values, so that all channels can be adjusted simultaneously. However, as long as the correspondence of the output luminance to the input gradation value can be obtained as the reference signal, for example, a monochromatic video signal for evaluating each of the red (R), green (G), and blue (B) channels individually. May be output.

PC40 is the input tone value of each channel while maintaining the R = G = B, the input tone value to the inflection point gradation value I _t from 0 (in a low gradation region) is varied. Then, the TV 100 waiting in the signal waiting state outputs the reference signal input in step S125 to the liquid crystal module 180 while performing gamma correction. Images displayed on the liquid crystal module 180, a black screen input tone value R = G = B = 0, the brightness is light gray screen increases as it approaches the input tone value R = G = B = I _t . The color analyzer 30 picks up this image with the CCD image pickup device 31 or the like and detects it as a luminance value. The color analyzer 30 is connected to the adjustment computer 40 and measures the correspondence between the input gradation value and the luminance value of the captured image.

  In step S130, the PC 40 analyzes the correspondence relationship between the input gradation value acquired by the color analyzer 30 and the luminance value of the image. FIG. 7 is a graph showing the state of analysis performed in step S130. In the figure, the horizontal axis represents the input gradation value, and the vertical axis represents the image luminance. Therefore, the correspondence between the input gradation value and the luminance value of the image can be expressed as a luminance curve S. Here, since the video displayed on the liquid crystal module 180 is an image based on the video signal after the gamma correction, it is desirable that the luminance change based on the input gradation value is linear. That is, if the luminance value of the image is proportional to the input gradation value as indicated by an ideal straight line (curve) L indicated by diagonal lines in the graph, the gamma correction performed by the TV 100 compensates for the nonlinearity. I can say. Note that data indicating the correspondence relationship of the ideal straight line L is stored in advance in the HD 41e, and is read and used as appropriate.

In each gradation value of the graph, an allowable width (± d) of a predetermined luminance value is set on the high luminance side and the low luminance side of the luminance value on the ideal line L, and the range of the allowable width of the predetermined luminance value The inner area is indicated by hatching. In step S135, if the actual luminance curve S is within the allowable range in all gradations, it is determined that the gamma correction in the low gradation region based on the default low gradation γ value γ ₁ is appropriate. If the actual luminance curve S is not within the allowable range, it is determined that the gamma correction in the low gradation region based on the default low gradation γ value γ ₁ is not appropriate.

  Note that, as shown in the figure, the allowable width may be a constant allowable width (for example, ± d) for all gradation values to the high luminance side and the low luminance side, or may be a predetermined value for the luminance value of the ideal line L. The range of the ratio may be an allowable width. Of course, an allowable width may be applied according to the ideal accuracy of gamma correction. In the present embodiment, the ideal straight line L is a straight line, but it is not necessarily a straight line, and may be a curved line or the like. In other words, depending on the conditions of other components and the like, an ideal gamma correction may be realized by using a curve or the like, and a target luminance characteristic may change depending on the viewer's preference.

  Further, by determining whether or not the actual luminance curve S falls within the allowable range in all gradations, it is possible to determine whether or not gamma correction is appropriate over all gradations. However, it is not always necessary to determine whether gamma correction is appropriate for all gradations. For example, when the range of gradation values that may cause variations in gamma characteristics for each machine is known in advance, only the range of gradation values may be evaluated to improve processing efficiency.

Here, when the actual luminance curve has a luminance value higher than the upper limit value of the allowable width indicated by diagonal lines, the corrected output gradation value is too large, and thus it is necessary to reduce the corrected output gradation value. . Accordingly, in step S140, the value of the low gradation γ value γ ₁ is reduced by 5%, thereby reducing the bulge of the γ curve C shown in FIG. On the other hand, when the actual luminance curve has a luminance value lower than the lower limit value of the allowable width indicated by the diagonal lines, the corrected output gradation value is too small, and thus the corrected output gradation value needs to be increased. . Therefore, in step S140, the value of the low gradation γ value γ ₁ is increased by 5% to increase the bulge of the γ curve C shown in FIG.

The low gradation γ value γ ₁ increased or decreased in step S140 is output to the TV 100. The default low gradation gamma value gamma ₁ at accepts an input step S150 in the low gradation gamma value gamma ₁ which is increased or decreased in step S145 in TV100 is a was increased or decreased low gradation gamma value gamma ₁ The latter is stored, and the latter is stored in the EEPROM 112. Further, the replaced low tone γ value γ ₁ is substituted as a parameter of the function of the gamma correction curve expressed by the above formula (1), thereby generating a correction table. Then, the default correction table is replaced with the generated correction table and stored in the EEPROM 112. Accordingly, the video data input to the TV 100 thereafter is gamma-corrected using the correction table 113 that has been replaced and stored in step S150.

On the other hand, when the PC 40 increases or decreases the value of the low gradation γ value γ ₁ in step S140 and outputs it to the TV 100, step S120 and subsequent steps are repeated. However, the image luminance value of the liquid crystal module 180 analyzed again in step S130 is an output image of image data that has been subjected to gamma correction using the replaced correction table 113. Therefore, it can be expected to be closer to the ideal curve than the first time. If the luminance value does not fall within the allowable range again in step S135, the same processing is further repeated. That is, by repeating the processing of steps S120 to S140, the brightness value that greatly deviated from the ideal curve in the initial stage can be gradually made closer to the ideal curve. At this time, since the TV 100 stands by in the factory mode, the low gradation γ value γ ₁ and the correction table are sequentially stored in the EEPROM 112 according to the request of the PC 40.

In step S135, if the luminance value falls within the allowable range, the setting of the low gradation γ value γ ₁ is terminated assuming that the low gradation γ value is appropriate, and the high gradation γ value γ ₂ after step S155 is set. Start setting. In step S155, the PC 40 generates a reference signal and outputs the reference signal to the TV 100 standing by in a signal waiting state. The reference signal output here is a gray signal in which the input gradation value of each channel is R = G = B, as in step S120. In a state where the input tone value of each channel is kept R = G = B, the input tone values from I _t to 255 (maximum gradation value I _r), i.e. varying in the high tone region.

The TV 100 waiting in the video signal waiting state outputs a video signal based on the reference signal to the liquid crystal module 180 while performing gamma correction in step S160. Images displayed on the liquid crystal module 180, the gray screen input tone value _{R = G = B = I t} , the brightness is increased white screen as it approaches the input tone value R = G = B = 255. The color analyzer 30 picks up this image with the CCD image pickup device 31 or the like and detects it as a luminance value. In step S165, as in step S130, the correspondence between the actual luminance value and the input gradation value is compared with the ideal straight line L stored in the HD 41e. That is, it is determined whether or not the default high gradation γ value γ ₂ is a value capable of gamma correction that can compensate for linearity. Also in step S170, as in step S135, it is determined whether or not the actual luminance value falls within the allowable range.

Here, when the actual luminance curve has a luminance value higher than the upper limit value of the allowable width indicated by diagonal lines, the corrected output gradation value is too large, and thus it is necessary to reduce the corrected output gradation value. . Accordingly, in step S175, the value of the high gradation γ value γ ₂ is reduced by 5% to increase the bulge of the γ curve C shown in FIG. 4 toward the output gradation value side. On the other hand, if the actual luminance curve has a luminance value lower than the lower limit value of the allowable width indicated by diagonal lines, the corrected output gradation value is too large, and thus it is necessary to increase the corrected output gradation value. . Accordingly, in step S175, the bulge of the γ curve C shown in FIG. 4 toward the input gradation value side is reduced by reducing the value of the high gradation γ value γ ₂ by 5%.

Then, the TV 100 receives the output of the increased and decreased high gradation γ value γ ₂ in step S180. If the increased / decreased high gradation γ value γ ₂ is output, step S185 is executed assuming that the high gradation γ value γ ₂ is input. In step S185, a default replaced by high gradation gamma value gamma ₂ high gradation gamma value gamma ₂ which is increased or decreased, the function of the gamma correction curves shown high gradation gamma value gamma ₂ by replacing the above formula (2) By substituting as a parameter, a new correction table is generated. That is, the default correction table is replaced with the correction table based on the increased / decreased high gradation γ value γ ₂ and stored in the EEPROM 112. Therefore, the image output to the liquid crystal module 180 thereafter is gamma-corrected by the correction table based on the new high gradation γ value γ ₂ .

When the high gradation γ value γ ₂ increased or decreased is output to the TV 100, the PC 40 repeats the processing of steps S155 to S175. However, since the image displayed on the liquid crystal module 180 in step S160 is closer to the ideal curve than in the previous time, the possibility that the actual luminance value falls within the allowable range in step S170 that is repeated increases. That is, by repeatedly executing the processing of steps S155 to S175, the actual luminance value can be made asymptotic to the ideal curve until it falls within the allowable range. If it is determined in step S170 that the actual luminance value is within the allowable range, the setting process of the high gradation γ value γ ₂ is completed. Of the processes in steps S110 to S175 described above, the process performed by the PC 40 corresponds to the parameter setting control means in the present invention.

On the other hand, if the update of the high gradation γ value γ ₂ is not accepted in step S180, the TV 100 also ends the factory mode in step S190. That is, the low gradation γ value γ ₁ and the high gradation γ value γ ₂ and the correction table cannot be rewritten. At this time, the correction table last generated in step S185 or step S150 or the default correction table is finally stored. In any case, the correction table stored in the step S190 ensures that the actual luminance is within the allowable range in both the low gradation region and the high gradation region. Therefore, the TV 100 that has been adjusted and shipped in step S190 can realize linearity of output luminance by gamma correction. In addition, since the above processing is performed for each aircraft, it is possible to realize a uniform output characteristic by compensating for an error in gamma characteristics for each aircraft.

  As described above, in the present invention, by adjusting the gamma correction table for each body of each panel display television, it is possible to make the gamma characteristic varying for each body uniform. Further, since the panel display television generates the gamma correction table from the function of the gamma correction curve, the adjusting device does not need to output the data of the correction table itself to the panel display television. That is, it is sufficient that the adjusting device outputs the adjusted parameter of the function of the gamma correction curve to the panel display television. Therefore, the time required for data transmission can be shortened, and transmission errors can be made difficult to occur.

  Further, as means for preventing the data of the correction table itself from being output from the adjusting device to the panel display television, a plurality of gamma correction tables are stored in advance in the EEPROM of the panel display television, and the plurality of gamma correction tables are stored in accordance with an instruction from the adjusting device. A system that selects and uses the most suitable gamma correction table among the gamma correction tables is also conceivable. However, in this system, it is necessary to store a plurality of gamma correction tables in an EEPROM or the like, and it is difficult to realize with an EEPROM or the like having a small storage capacity.

It is a system configuration figure showing the schematic structure of an example of a panel display television adjustment system. It is a block diagram which shows the structure of a color analyzer. It is a block diagram which shows the structure of a liquid crystal television. It is a figure which shows a gamma curve correction table typically. It is a block diagram which shows schematic structure of the computer for adjustment. It is a flowchart for the flow of adjustment processing of the panel display television adjustment system. It is a figure which shows the parameter adjustment process typically.

Explanation of symbols

30 ... Color analyzer 40 ... Computer for adjustment (PC)
40a ... communication port 40b ... I / O board 41a ... CPU
41b ... ROM
41c ... RAM
41e ... Hard disk (HD)
100 ... Liquid crystal television (TV)
DESCRIPTION OF SYMBOLS 101 ... Main-body part 102 ... IIC bus 103 ... IIC bus data port 110 ... Microcomputer 111 ... Operation panel 112 ... EEPROM
113 ... γ curve correction table (correction table)
114: Gamma correction curve function 115 ... Parameter 130 ... Video signal processing unit 153 ... Gamma correction circuit 155 ... Memory 170 ... Gamma correction table generation circuit 180 ... Liquid crystal module (liquid crystal display unit)
181 ... Control circuits 182-184 ... Liquid crystal panel 185 ... Backlight 186 ... Inverter 190 ... Power supply device 199 ... Display screen CLK1, CLK2 ... Oscillator circuit

Claims (7)

Based on the input video signal, it generates video data represented by digital gradation values for each of the many pixels that make up the screen,
A correction table indicating a correspondence relationship between the input gradation value and the output gradation value for compensating the nonlinear characteristic and displaying on the display panel is stored in the EEPROM.
A panel display television that performs gamma correction by converting the video data with reference to the correction table;
A panel display television adjustment system comprising an adjustment device for setting a parameter for compensating for the nonlinear characteristic in the panel display television,
The panel display television is
A low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and a gradation range larger than the inflection point gradation value A correction table generation for generating the correction table including a predetermined correction curve passing through the inflection point based on the parameter corresponding to the high gradation γ value for generating a correction curve using a gamma correction curve in Means,
Parameter storage means for inputting the parameters set by the adjustment device and storing them in the EEPROM;
A correction table updating unit for generating the correction table based on the stored parameter and storing the generated correction table in the EEPROM;
The adjusting device is
And parameter setting means for setting the parameters stored in the parameter storage unit in the panel display television,
Video signal output means for outputting a gray reference video signal while changing the gradation value in a range of all gradation values for the panel display television;
It is possible to measure the brightness of the screen displayed by the panel display television based on the output reference video signal, and the correspondence between the same gradation value and the same brightness according to the change of the same gradation value Measuring means for measuring
It is determined whether or not the correspondence relationship between the gradation value and the luminance is linear within a predetermined allowable range based on the measurement result by the measuring means. A panel display television adjustment system comprising: parameter setting control means for increasing and decreasing the parameter value to execute setting by the parameter setting means, output by the video signal output means, and measurement by the measuring means . Based on the input video signal, it generates video data represented by digital gradation values for each of the many pixels that make up the screen,
A correction table indicating a correspondence relationship between the input gradation value and the output gradation value for compensating the nonlinear characteristic and displaying on the display panel is stored in the nonvolatile memory,
A panel display television that performs gamma correction by converting the video data with reference to the correction table;
A panel display television adjustment system comprising an adjustment device for setting a parameter for compensating for the nonlinear characteristic in the panel display television,
The panel display television is
A low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and a gradation range larger than the inflection point gradation value A correction table generation for generating the correction table including a predetermined correction curve passing through the inflection point based on the parameter corresponding to the high gradation γ value for generating a correction curve using a gamma correction curve in Means,
Parameter storage means for inputting the parameters set by the adjustment device and storing them in a nonvolatile memory;
A correction table updating unit for generating the correction table based on the stored parameter and storing the generated correction table in the nonvolatile memory;
The adjusting device is
And parameter setting means for setting the parameters stored in the parameter storage unit in the panel display television,
Video signal output means for outputting a video signal while changing a gradation value within a predetermined range with respect to the panel display television;
The brightness of the screen displayed by the panel display television can be measured based on the output video signal, and the correspondence between the same gradation value and the same brightness according to the change of the same gradation value can be measured. Measuring means for measuring;
Based on the measurement result by the measuring means, it is determined whether or not the correspondence relationship between the gradation value and the luminance is within a predetermined allowable range. If it is out of the allowable range, the value of the parameter is increased or decreased. And a parameter setting control means for executing the setting by the parameter setting means, the output by the video signal output means, and the measurement by the measuring means. The parameter setting control means includes
It is determined whether or not the correspondence relationship between the gradation value and the luminance is linear within a predetermined allowable range based on the measurement result by the measuring means, and if the linear relationship is not linear within the allowable range The parameter setting control means for executing the setting by the parameter setting means, the output by the video signal output means, and the measurement by the measuring means by increasing / decreasing the value of the parameter. Panel display television adjustment system. The video signal output means includes
4. The panel display television adjustment according to claim 2, wherein a gray reference image signal is output while changing a gradation value within a predetermined range with respect to the panel display television. system. The video signal output means includes
5. The panel display television adjustment according to claim 2, wherein a video signal is output while changing a gradation value in a range of all gradation values with respect to the panel display television. system. Based on the input video signal, it generates video data represented by digital gradation values for each of the many pixels that make up the screen,
A correction table indicating a correspondence relationship between the input gradation value and the output gradation value for compensating the nonlinear characteristic and displaying on the display panel is stored in the nonvolatile memory,
For a panel display television that performs gamma correction by converting the video data with reference to the correction table,
A panel display television adjustment method for setting a parameter for compensating for the nonlinear characteristic in the panel display television using an adjustment device,
The panel display television is
A low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and a gradation range larger than the inflection point gradation value A correction table generation for generating the correction table including a predetermined correction curve passing through the inflection point based on the parameter corresponding to the high gradation γ value for generating a correction curve using a gamma correction curve in Process,
A parameter storage step of inputting the parameters set by the adjustment device and storing them in a nonvolatile memory;
It performs a correction table updating step of storing a correction table the generated while generating the correction table based on the parameters the stored in the nonvolatile memory,
The adjusting device is
A parameter setting step of setting the parameters stored in the parameter storage step in the panel display television,
A video signal output step of outputting a video signal while changing a gradation value within a predetermined range with respect to the panel display television;
The brightness of the screen displayed by the panel display television can be measured based on the output video signal, and the correspondence between the same gradation value and the same brightness according to the change of the same gradation value can be measured. Measuring process to measure,
Based on the measurement result of the measurement process, it is determined whether or not the correspondence between the gradation value and the luminance is within a predetermined allowable range. If it is out of the allowable range, the value of the parameter is increased or decreased. panel display television adjustment method characterized by performing the parameter setting control process to execute the measurement by the output and the measurement process by the setting and the video signal output step by the parameter setting step in. Based on the input video signal, it generates video data represented by digital gradation values for each of the many pixels that make up the screen,
A correction table indicating a correspondence relationship between the input gradation value and the output gradation value for compensating the nonlinear characteristic and displaying on the display panel is stored in the nonvolatile memory,
A panel display television that performs gamma correction by converting the video data with reference to the correction table,
A low gradation γ value for generating a correction curve using a gamma correction curve in a gradation range smaller than the inflection point gradation value corresponding to the inflection point, and a gradation range larger than the inflection point gradation value A correction table generating means for generating the correction table including a predetermined correction curve passing through the inflection point based on a parameter including a high gradation γ value for generating a correction curve using a gamma correction curve in ,
Parameter storage means for inputting the parameters adjusted by the adjustment device connected to the outside and storing them in a nonvolatile memory;
And a correction table updating means for generating the correction table based on the stored parameters and storing the generated correction table in the nonvolatile memory.

Images