JP2008211296A - Television receiver and white balance adjusting method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve picture display performance by preventing a deviation in white balance due to signal processing for various adjustments and corrections of a video signal processing unit block by simple configurations and adjustments. <P>SOLUTION: The white balance of three primary color signals of a display image is roughly adjusted by adjusting characteristics of signal processing of a panel signal processing unit 13 provided behind a color matrix circuit unit 12 of the video signal processing unit block 3. Then, a gamma correcting circuit unit 15 provided at the final stage of the video signal processing unit block 3 sets gamma correction characteristics of the two primary color signals of red and blue having a small influence on the lightness of a picture to characteristics finely adjusted to correct a deviation in white balance due to various signal processing of the video signal processing unit block 3, and drives a display device 17 for display with the three primary color signals of the display image after the rough adjustment and fine adjustment to prevent the deviation in white balance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a television receiver including a thin display panel display device such as a liquid crystal display panel or a plasma display panel, and a white balance adjustment method thereof, and more particularly to prevention of white balance adjustment deviation.

  Conventionally, in a television receiver having a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel, a received video signal reproduced from a received signal of a television broadcast or an external input video signal is converted into a digital video signal. The screen is displayed on the display device through the processing block.

  In the video signal processing block, the received video signal and the external input video signal are subjected to A / D conversion and YC separation as necessary, and then automatic brightness level adjustment (ABL), automatic color level Adjustment (ACL), scan conversion, and the like are performed.

  After that, it is converted into digital RGB primary color signals by color matrix processing in the color matrix circuit unit, and amplitude adjustment (signal amplification), pedestal clamp, Various adjustments and corrections such as contrast adjustment, dither correction, and tint correction are performed, and the three primary color signals subjected to these adjustments and corrections are supplied to the display device as display drive signals.

  At this time, the panel signal processing unit automatically adjusts the white balance by performing level adjustment related to white balance such as amplitude adjustment of the three primary color signals, DC level adjustment of the pedestal clamp (cutoff level adjustment), and contrast adjustment (for example, , See Patent Document 1).

Further, the correction of the gamma characteristic due to the characteristics of the panel or backlight of the display device has conventionally been performed by using the three primary color signals before or after the white balance adjustment and the set reference correction characteristics (for example, brightness adjustment). Gamma correction is performed with a predetermined broken line approximation characteristic with respect to a change in gradation (see, for example, Patent Document 2).
JP-A-2005-191618 (paragraphs [0007]-[0008], [0017], FIG. 1, etc.) JP 2003-122330 A (paragraphs [0004]-[0008], [0019], FIG. 1 etc.)

  In the case of the conventional television receiver, for example, in the adjustment process at the time of manufacture, the panel signal processing unit has characteristics of signal level adjustment such as amplitude adjustment, DC level adjustment, contrast adjustment, etc. It is adjusted and set so that white balance can be obtained in the gradation state.

  In the adjustment step and the like, other adjustments such as dither correction and tint correction in the subsequent circuit unit of the panel signal processing unit and setting of signal processing characteristics for correction are also performed.

  On the other hand, the gamma correction characteristics of the three primary color signals are obtained by, for example, setting the signal level adjustment characteristics related to white balance by the gamma correction circuit section provided in the panel signal processing section of the video signal processing section block or in the subsequent stage. Are independently set to the reference correction characteristics of the preset three primary color signals.

  In this case, the three primary color signals output from the color matrix circuit unit of the panel signal processing unit are subjected to white balance adjustment by gamma correction fixed to the reference correction characteristic and the level adjustment set by the signal processing unit. However, after the level adjustment, the other adjustment and correction signal processing of the video signal processing unit block is performed, so that a white balance shift occurs, and depending on the brightness gradation state of the screen of the display device, There is a problem that the white balance is out of the allowable range, the screen becomes unsightly, and the screen display performance is impaired.

  Further, when the display device has a large screen, it is difficult to make the so-called gamma characteristic uniform over the entire screen based on the panel characteristics, the backlight characteristics, and the like. For this reason, in particular, when a large-screen display device is provided, it is difficult to set the gamma correction characteristics of the three primary color signals of the entire screen as the reference correction characteristics to achieve a good white balance of the entire screen of the display device.

  When a display device with a large screen is provided, the white balance of the three primary color signals subjected to the level adjustment is shifted by other adjustment and correction signal processing of the video signal processing block, and the gamma characteristic of the display device is changed to the screen. Since it differs depending on the position, the deviation of the white balance of the display screen of the display device becomes more conspicuous.

  The present invention is a television receiver equipped with a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel, and is caused by various adjustment and correction signal processing of the video signal processing block with a simple configuration and adjustment. The purpose is to improve the screen display performance by preventing the deviation of the white balance, and to further improve the screen display performance by preventing the deviation of the white balance depending on the screen position of the display device. To do.

  In order to achieve the above object, a television receiver of the present invention is provided in a video signal processing block in a television receiver including a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel. A color matrix circuit unit for outputting the three primary color signals of the display image, and an amplitude adjustment and a DC level related to the white balance so that the white balance can be obtained by the gamma correction of the reference correction characteristic. A signal level adjustment characteristic such as adjustment is set, and a panel signal processing unit for performing the signal level adjustment set for the input three primary color signals, and the input 3 provided at the final stage of the video signal processing block. The gamma correction characteristics of the green primary color signal among the primary color signals are set to the green reference correction characteristics, and the remaining red, blue The reference corrections for red and blue so that the gamma correction characteristics of the two primary color signals can correct white balance deviations associated with the setting of various signal processing characteristics of the video signal processing block including the characteristic setting of the signal level adjustment. A three-primary color signal output from the gamma correction circuit unit, and a gamma correction circuit unit that performs gamma correction on the input three primary color signals with the set gamma correction characteristics. The display device is driven by the display (claim 1).

  In addition, the gamma correction characteristics of the two primary color signals of the gamma correction circuit unit in the television receiver of the present invention are finely adjusted individually for each portion of the display screen of the display device in which a deviation in white balance exceeds an allowable amount. The characteristic is set as described above (claim 2).

  Next, a white balance adjusting method for a television receiver according to the present invention includes a video signal processing unit in a white balance adjusting method for a television receiver including a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel. In the state where the gamma correction characteristics of the three primary color signals of the gamma correction circuit section provided at the last stage of the block are set to the respective reference correction characteristics, 3 of the display image output from the color matrix circuit section of the video signal processing section block Set characteristics of signal level adjustment such as amplitude adjustment and direct current level adjustment related to white balance of the panel signal processing unit to which the primary color signal is input, and include the characteristics of the signal level adjustment of each part of the video signal processing unit block After setting the signal processing characteristics, do not measure the white balance state of the display screen of the display device. Further, the gamma correction characteristics of the two primary color signals of red and blue of the gamma correction circuit unit are finely adjusted and set so as to correct the deviation of the weight balance from the reference correction characteristics of red and blue, and the panel signal The white balance of the three primary color signals output from the gamma correction circuit unit and driving the display device is adjusted by the level adjustment of the processing unit and the gamma correction of the gamma correction circuit unit. 3).

  Further, in the white balance adjustment method of the television receiver of the present invention, the fine adjustment of the gamma correction characteristics of the two primary color signals of the gamma correction circuit unit is such that the deviation of the white balance of the display screen of the display device exceeds an allowable amount. It is characterized in that it is performed individually for each of the following points (claim 4).

  According to the first and third aspects of the present invention, characteristics of signal level adjustment such as amplitude adjustment and DC level adjustment of a panel signal processing unit provided at a subsequent stage of the color matrix circuit unit of the video signal processing block are the video signal processing. The gamma correction circuit unit provided at the last stage of the block is set so that white balance can be obtained in a state where the three primary color signals are gamma-corrected with the respective reference correction characteristics, and the color matrix circuit unit outputs based on the setting. A so-called coarse adjustment of white balance is performed on the three primary color signals of the display image.

  Further, in the gamma correction circuit unit provided at the final stage of the video signal processing block, the gamma correction characteristics of the two primary color signals of red and blue, which have less influence on the screen brightness among the three primary color signals of the display image, The correction characteristics are set by fine adjustment from the respective reference correction characteristics so as to correct the deviation of the white balance based on the various signal processes of the video signal processing block.

  The gamma correction circuit unit applies a gamma correction to the green primary color signal having a large influence on the screen brightness among the three primary color signals of the display image on which the white balance is roughly adjusted. Of the three primary color signals of the display image that have been subjected to the white balance coarse adjustment, the two primary color signals of red and blue that have little influence on the screen brightness are subjected to various signal processing of the video signal processing block. The gamma correction is performed with the gamma correction characteristics set by fine adjustment from the respective reference correction characteristics so as to correct the white balance deviation based on the white balance, and the white balance is applied to the three primary color signals of the display image subjected to the coarse adjustment. The so-called fine adjustment is performed.

  Then, the display device is driven to display by the three primary color signals of the display image subjected to the white balance coarse adjustment and the fine adjustment.

  In this case, even if the white balance of the three primary color signals of the display image roughly adjusted by the signal level adjustment of the panel signal processing unit is shifted by adjustment or correction of other circuit units of the video signal processing unit block, The shift is corrected by gamma correction of the two primary color signals of red and blue in the final stage gamma correction circuit. Since the green primary color signal that affects the brightness is gamma-corrected by the reference correction characteristics, the three primary color signals after the gamma correction output from the gamma correction circuit section are the gradation characteristics before and after the gamma correction. Hardly changes.

  For this reason, the display device is driven by the three primary color signals of the display image that prevents the white balance from shifting, and the white balance does not deviate from the allowable range even if the brightness gradation changes, and the screen display performance is remarkably improved. To do.

  Therefore, in a television receiver equipped with a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel, a gamma correction circuit unit is provided at the final stage of the video signal processing block, and the two primary color signals of red and blue are displayed. A simple configuration and adjustment that fine-tunes the gamma correction characteristics from the respective reference correction characteristics to prevent misalignment of the display device's display screen due to various adjustments and correction signal processing of the video signal processing block. In addition, the screen display performance can be improved.

  According to the second and fourth aspects of the present invention, the gamma correction characteristics of the two primary color signals of red and blue of the gamma correction circuit section are different from each other on the display screen of the display device in which the deviation of white balance exceeds an allowable amount. Since the display device has a large screen and its gamma characteristics are not uniform over the entire screen, white balance deviation due to the screen position can also be prevented. The screen display performance of this type of television receiver can be further improved.

  Next, in order to describe the present invention in more detail, an embodiment thereof will be described in detail with reference to FIGS.

  FIG. 1 shows a block configuration of the television receiver 1, and FIG. 2 shows an example of a gamma correction characteristic setting device. 3A and 3B are explanatory diagrams of a method for setting gamma correction characteristics. FIG. 3A shows an example of selectable gamma correction characteristics, FIG. 3B shows an example of gradation change in screen brightness, and FIG. An example of selecting correction characteristics is shown.

(Configuration and operation of television receiver 1)
The television receiver 1 in FIG. 1 can receive and display, for example, Japanese analog TV broadcasts and digital TV broadcasts (terrestrial digital broadcasts, BS digital broadcasts, CS digital broadcasts, etc.), and an external input terminal unit not shown. It is also possible to display externally input analog and digital video signals (external input video signals) input to.

  When analog TV broadcast is received and displayed on the screen according to the user's channel selection operation or timer reservation setting, the reception signal of the analog TV broadcast of the reception channel is input to the reception demodulation processing unit 2, and the reception demodulation processing unit 2 In this way, the analog composite signal (received video signal) of the reception channel is reconstructed by the well-known NTSC reception demodulation process.

  The analog composite signal is converted into a digital signal by the A / D converter 4 of the video signal processing block 3 and separated into a digital luminance signal Y and a color signal C by the YC separator 5. The color signal C is two known color difference signals.

  The composite signal of the YC separation unit 5 is also sent to the synchronization separation unit 6, and the synchronization separation unit 6 separates and extracts the synchronization signal from the composite signal to control the operation of the television receiver 1. 7 is sent as a reference signal such as reproduction timing.

  Further, the luminance signal Y and the color signal C of the YC separation unit 5 are input to the YC limiting circuit unit 8 and subjected to digital automatic luminance level adjustment (ABL) and automatic color level adjustment (ACL), and then noise reduction ( NR) circuit unit 9 is sent to scan conversion unit 10, and scan conversion unit 10 performs scan conversion from interlaced scan (i) to progressive scan (p).

  Next, the luminance signal Y and the color signal C converted to progressive scanning are sent from the scanning conversion unit 10 to the image quality / field angle correction unit 11, for example, after being subjected to resize field angle correction or sharpness image quality correction, The three primary color signals of red (R), green (G), and blue (B) (hereinafter, the three primary color signals are referred to as RGB signals) which are sent to the color matrix circuit unit 12 and subjected to known matrix processing of the color matrix circuit unit 12 Is converted to

  The RGB signals are sent to the panel signal processing unit 13 at the next stage (following stage) of the color matrix circuit section 12. The panel signal processing unit 13 performs known signal level adjustments such as amplitude adjustment, DC level adjustment (pelestal clamp adjustment), contrast adjustment and the like on the RGB signal with the set characteristics such as signal gain and DC clamp level.

  At this time, the RGB signal is adjusted for each signal level with characteristics set for each primary color signal, and so-called rough adjustment of white balance is performed by the adjustment. The conventional white balance adjustment is only this rough adjustment.

  Further, the RGB signal that has passed through the panel signal processing unit 13 is input to the hue correction unit 14, and the hue correction unit 14 performs other corrections such as tint correction and dither correction on the RGB signal with the set signal processing characteristics. Make various adjustments and corrections.

  The RGB signal that has passed through the hue correction unit 14 is input to a gamma correction circuit unit 15 provided at the final stage of the video signal processing block 3, and the gamma correction circuit unit 15 is a correction data storage unit 16 of a nonvolatile memory. The gamma correction is performed for each signal on the RGB signal input with the gamma correction characteristic of each of the three primary colors of RGB based on the correction data for each of the three primary colors held in the.

  At this time, a green primary color signal (hereinafter referred to as a G signal) that affects the brightness of the screen is a gamma signal having the same G signal reference correction characteristic set based on a characteristic standard of the display device 17 described later. The two primary color signals of red and blue that are corrected but have little influence on the brightness of the screen (hereinafter, the primary color signal of red is referred to as R signal and the primary color signal of blue as B signal) Gamma correction is performed with the respective gamma correction characteristics set by fine adjustment from the reference correction characteristics of the R signal and the B signal so as to correct the white balance deviation based on the setting of the signal processing characteristics. Then, by the gamma correction of the R signal and the B signal, the RGB signal having passed through the gamma correction circuit unit 15 is finely adjusted to correct the deviation of the white balance.

  Then, the RGB signal subjected to gamma correction by the gamma correction circuit unit 15 is displayed on the display device 17 of a thin display panel such as a liquid crystal display panel (LCD) or a plasma display panel (PDP) via a display driving unit (not shown). A display image of the received analog television broadcast is displayed on the display device 17 by the display drive signal supplied as a signal.

  Next, when a digital television broadcast is received and displayed on the screen in accordance with the user's channel selection operation or timer reservation setting, the reception signal of the digital television broadcast of the reception channel is input to the reception demodulation processing unit 2, and the reception demodulation processing unit The digital signal of the reception channel is formed by the well-known digital television broadcast reception demodulation process of the TS decoder built in the signal 2 and the luminance signal (Y signal) and the color signal (reconstructed as the received video signal of the digital signal) C signal) is input to the YC limiting circuit unit 8, and the synchronization signal is input to the synchronization separation unit 6.

  Then, the YC limiting circuit unit 8 to the gamma correction circuit unit 15 of the video signal processing block 3 perform the same signal processing as when receiving the above analog television broadcast and displaying it on the screen, and pass through the gamma correction circuit unit 15. The received display image of the digital television broadcast is displayed on the display device 17 by the display drive of the RGB signals.

  At this time, the received RGB signal of the digital television broadcast is subjected to white balance coarse adjustment by the signal level adjustment of the panel signal processing unit 13, and the white balance of the RGB signal of the R signal and B signal of the gamma correction circuit unit 15 is adjusted. Fine adjustments are made.

  Next, when an analog composite external input video signal is displayed on the screen, the external input video signal is input to the A / D converter 4, and the A / D converter 4 to the gamma correction circuit of the video signal processing block 3. The unit 15 performs the same signal processing as that for receiving the above-mentioned analog television broadcast on the external input video signal and displaying it on the screen, and displays the analog external input video by driving the RGB signal through the gamma correction circuit unit 15. The display image of the signal is displayed on the display device 17 on the screen.

  When a digital external input video signal is displayed on the screen, the external input video signal is demodulated by the TS decoder of the reception demodulation processing unit 2, and the YC limiting circuit unit 8 to the gamma correction circuit of the video signal processing block 3 are processed. The unit 15 performs the same signal processing as when receiving the above-mentioned digital TV broadcast on the external input video signal and displaying it on the screen, and displays the RGB signal through the gamma correction circuit unit 15 to display the digital external input video. The display image of the signal is displayed on the display device 17 on the screen.

  Even in the screen display of the analog and digital external input video signals, the white balance is roughly adjusted by the signal level adjustment of the panel signal processing unit 13, and the R signal and B signal of the gamma correction circuit unit 15 are corrected by gamma correction. The white balance is finely adjusted.

(Setting of the white balance of the television receiver 1)
Next, setting of the white balance coarse adjustment by the signal level adjustment of the panel signal processing unit 13 described above, and the fine adjustment of the white balance by gamma correction of the R signal and B signal of the gamma correction circuit unit 15 will be described.

  First, the rough adjustment of the white balance by the signal level adjustment of the panel signal processing unit 13 described above is performed, for example, in the adjustment process at the time of manufacturing the television receiver 1, the amplitude adjustment related to the white balance of the panel signal processing unit 13, DC Signal level adjustment characteristics such as level adjustment (pelestal clamp adjustment) and contrast adjustment are set as those for gamma correction of RGB signals with the reference correction characteristics.

  Specifically, it is assumed that the RGB signal is subjected to gamma correction with the respective reference correction characteristics as in the conventional case, and the signal level adjustment characteristic of the panel signal processing unit 13 is previously set to a predetermined characteristic similar to the conventional one. In the adjustment step, the panel signal processing unit 13 adjusts the signal level of each unit to a specified level while measuring the voltage or the like in the conventional manner, and sets the characteristics of the signal level adjustment. The coarse adjustment of white balance is set by.

  Next, setting of fine adjustment of white balance by the gamma correction circuit unit 15 will be described.

  In the adjustment process at the time of manufacture of the television receiver 1, before the setting of the signal level adjustment or the like, each reference set in advance at the stage of design or the like as correction data of the gamma correction characteristics of the RGB signal Correction data of correction characteristics is written and held in the correction data storage unit 16. For this reason, when the signal level adjustment is set, the gamma correction circuit unit 15 is initially set so as to perform gamma correction on the RGB signal with the reference correction characteristic.

  After the signal level adjustment is set, various other adjustments such as tint correction and dither correction of the hue correction unit 14 and the characteristics of the correction are adjusted and set, and then the final adjustment of the video signal processing block 3 is performed. As the setting, correction of the gamma correction characteristics of the R signal and B signal of the gamma correction circuit unit 15, that is, correction of the correction data of the R signal and B signal of the correction data storage unit 16 is performed.

  This correction is performed, for example, in the apparatus configuration shown in FIG. 2, and the light receiving sensor 18 is provided facing the display screen of the display device 17 of the television receiver 1 to be adjusted. An external video signal having a predetermined test color tone is input.

  Then, the brightness detection signal of the light receiving sensor 18 is input to the color analyzer 19, and the color analyzer 19 recognizes another brightness of R, G, and B from the detection signal, and these recognition data are converted into the computer configuration. This is sent to the inspection processing device 20.

  The inspection processing device 20 holds a data table of a plurality of types (for example, 60 types) of gamma correction characteristics of the solid line and the broken line shown in FIG. When correcting the correction data of the R signal and the B signal, an automatic adjustment program for the set gamma correction is executed. The solid line in FIG. 3A is the correction characteristic with γ = 1.0. The reference correction characteristic is, for example, a gamma correction characteristic with γ = 2.2.

  Then, by executing the automatic adjustment program, the inspection processing apparatus 20 obtains correction data of optimum correction characteristics of R and B from the data table based on the other recognition data of R, G, and B of the color analyzer 19. A correction is made by rewriting the correction data of the R signal and B signal in the correction data storage unit 16 to the selected correction data.

  Specifically, the brightness and contrast of the display device 17 are switched to the set low (X) and high (Y) brightness states in the state of the reference correction characteristic, and the low (X) and high ( For each brightness of Y), the gradation change of the brightness of each of R and B is measured, and, for example, as shown by the broken line in FIG. 3B, an actual measurement characteristic that increases or decreases from the target brightness of the solid line is obtained. .

  Then, for each of R and B, for each of the low (X) and high (Y) brightness, for example, the actually measured brightness of the broken line of the set point indicated by each arrow line in FIG. The selection of the optimum correction characteristic approaching the above is repeated a set number of times, and finally the optimum correction characteristic for both low (X) and high (Y) is determined and rewritten to the correction data of the correction characteristic.

  At this time, by correcting the correction data of the R signal and the B signal, after the level adjustment, the white balance deviation based on the other adjustment and correction signal processing of the video signal processing unit block 3 is corrected. The gamma correction characteristics of the R signal and the B signal are corrected and set to the correction characteristics finely adjusted from the respective reference correction characteristics. Note that the gamma correction characteristic of the G signal is maintained as the reference correction characteristic, so that the brightness gradation characteristic hardly changes depending on the gamma correction after fine adjustment. In other words, the brightness gradation characteristic is designed. There is no deviation from the expected characteristics. The fine adjustment also has an advantage of suppressing variations in brightness gradation based on individual variations in the characteristics of the display device 17.

  By performing the above-described coarse adjustment and fine adjustment of the white balance, the television receiver 1 that has undergone the adjustment process can display the three primary color signals of the display image that has undergone the coarse adjustment and fine adjustment of the white balance. Thus, the display device 17 is driven to display.

  Even if the white balance of the three primary color signals of the display image coarsely adjusted by the signal level adjustment of the panel signal processing unit 13 is shifted by adjustment or correction of other circuit units of the video signal processing unit block 3, the video signal processing block 3 is corrected by the gamma correction of the R signal and the B signal of the final stage gamma correction circuit unit 15, the display device 17 is driven to display with the RGB signal that prevents the white balance from being shifted, and the brightness level is reduced. Even if a tone change occurs, the white balance is not deviated from the allowable range, and the screen display performance is remarkably improved.

  By the way, especially when the display device 17 has a large screen of more than 30 inches, it is not easy to make the so-called gamma characteristic uniform over the entire screen based on the characteristics of the panel and the backlight. Even if it is uniform, the white balance is shifted.

  Therefore, when the television receiver 1 includes the display device 17 having a large screen, the gamma correction characteristics of the R signal and the B signal are corrected for each divided area of the display screen, and the display screen 17 has a white display screen. The fine adjustment of the white balance is individually set for each location where the balance deviation exceeds the allowable amount.

  Specifically, the display screen of the display device 17 is divided into a matrix having an appropriate number of matrices, and correction data for gamma correction characteristics of RGB signals is set for each divided region.

  First, the correction data of the RGB signal of each area is set to the data of the reference correction characteristic, and when the correction characteristics of the R signal and the B signal are corrected, the white balance deviation in the reference correction characteristic is detected for each area. For areas where the deviation exceeds the set allowable amount, the correction data of the R signal and B signal is corrected as described above, and the white balance deviation of the display screen of the display device 17 exceeds the allowable amount. Set the white balance fine adjustment individually for each.

  In this way, especially when the display device 17 has a large screen and its gamma characteristics are not uniform over the entire screen, it is possible to prevent white balance from being shifted due to the screen position. The screen display performance of the receiver 1 can be further improved.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. Any configuration may be employed as long as the panel signal processing unit 13 is provided at the subsequent stage of the matrix circuit unit 12 and the gamma correction circuit unit 15 at the final stage is provided.

  Further, the setting of the gamma correction characteristic of the gamma correction circuit unit 15 may be performed, for example, by holding data of an approximate characteristic equation, or may be performed by any other method.

  The present invention can be applied to white balance adjustment of a television receiver including a display device of various thin display panels such as a liquid crystal display panel and a plasma display panel.

It is a circuit block diagram of the principal part of the television receiver in one Embodiment of this invention. It is explanatory drawing of an example of an apparatus structure which performs the fine adjustment of the gamma correction characteristic of a television receiver same as the above. FIG. 6 is a characteristic diagram for explaining fine adjustment of the gamma correction characteristic of the television receiver.

Explanation of symbols

3 Video signal processing block 12 Color matrix circuit unit 15 Gamma correction circuit unit 16 Correction data storage unit 17 Display device

Claims (4)

  In a television receiver including a display device of a thin display panel such as a liquid crystal display panel or a plasma display panel, a color matrix circuit unit provided in a video signal processing unit block for outputting three primary color signals of a display image; Three primary color signals that are provided after the matrix circuit and are set with signal level adjustment characteristics such as amplitude adjustment and DC level adjustment related to white balance so that white balance can be achieved with gamma correction of the reference correction characteristics. The panel signal processing unit for adjusting the signal level set to the above and the video signal processing block at the last stage, and the gamma correction characteristic of the green primary color signal among the input three primary color signals is the green reference The gamma correction characteristics of the remaining two primary color signals, red and blue, are set as the correction characteristics. The three primary colors that are set to the correction characteristics finely adjusted from the reference correction characteristics of red and blue so as to correct the deviation of white balance due to the setting of various signal processing characteristics of the video signal processing block. And a gamma correction circuit section for performing gamma correction on the signal with each set gamma correction characteristic, and the display device is driven to display by the three primary color signals output from the gamma correction circuit section. Machine.   The gamma correction characteristics of the two primary color signals of the gamma correction circuit section are characteristics set by finely adjusting each of the display screens of the display device in which a white balance deviation exceeds an allowable amount. The television receiver according to claim 1.   In a white balance adjustment method for a television receiver having a thin display panel display device such as a liquid crystal display panel or a plasma display panel, the gamma of the three primary color signals of the gamma correction circuit unit provided at the final stage of the video signal processing unit block The amplitude related to the white balance of the panel signal processing unit to which the three primary color signals of the display image output from the color matrix circuit unit of the video signal processing unit block are input with the correction characteristics set to the respective reference correction characteristics After setting the signal level adjustment characteristics such as adjustment and DC level adjustment, and setting the signal processing characteristics of each part of the video signal processing block including the signal level adjustment characteristics, the white balance of the display screen of the display device While measuring the state, the gamma correction characteristics of the red and blue primary color signals of the gamma correction circuit section Fine adjustment is made to correct the deviation of the light balance from the reference correction characteristics of red, blue, and blue, and the gamma correction is performed by the level adjustment of the panel signal processing unit and the gamma correction of the gamma correction circuit unit. A white balance adjustment method for a television receiver, comprising: adjusting a white balance of three primary color signals output from a circuit unit and driving the display device.   The fine adjustment of the gamma correction characteristics of the two primary color signals of the gamma correction circuit unit is performed individually for each portion where the deviation of the white balance of the display screen of the display device exceeds an allowable amount. 3. A white balance adjustment method for a television receiver according to item 3.

Images