Device and method for fully automatic measurement and calibration of display gamma curve

Abstract

The invention discloses a device and a method for automatically measuring and calibrating a gamma curve of a display screen. The device comprises a brightness measurement device and a control and calculation assembly. The brightness measurement device is a programmable universal luminosity measurement instrument which performs communication with the control and calculation assembly and is one of the brightness measurement module, the illuminometer, the brightness meter, and the spectrometer of the communication module, the luminosity sensor adopting a photosensitive member and a Y spectrum responding matching optical filtering sheet, wherein the communication module can perform communication with the control and calculation assembly, and the communication module is connected to an electric parameter measurement module and communicates with the calculation assembly; and the control and calculation assembly performs communication with an upper computer software through a protocol order. The invention realizes the whole course automation of measurement and calibration, does not need the artificial setting of the display content, reading and manual correction of the gamma gauge. The invention is easy in operation and good in practicability, makes the uniformity correction of full gray scale bright color practical, realizes mixing usage of screen bodies with various batches and same specifications, and realizes the resource sharing.

Description

technical field [0001] The invention relates to a display screen, in particular to a device and method for fully automatic measurement and calibration of the gamma curve of a display screen. Background technique [0002] Light-emitting diode (Light Emitting Diode, abbreviated as LED) display screen, OLED screen, and OLED video wall control system to set display parameters, generally divided into basic operation interface and advanced operation interface. Complex parameter settings including grayscale, refresh rate, clock, connection, and port are often hidden in the advanced parameter setting interface, and the gamma value and gamma table are also preset by the manufacturer in the advanced parameter setting interface. Experienced engineers and technicians in the manufacturer need to enter a specific password or use other authority management methods to enter the advanced parameter setting interface for adjustment and setting, but screen terminal users generally cannot enter ...

AI Technical Summary

Problems solved by technology

Experienced engineers and technicians in the manufacturer need to enter a specific password or use other authority management methods to enter the advanced parameter setting interface for adjustment and setting, but screen terminal users generally cannot enter and adjust the gamma value, modify the gamma table, etc. step operation

However, the preset gamma value and gamma table, the gamma curve presented on the screen often have more or less errors from the theoretical value, especially in the low gray scale of 0-30, as the gray scale gradually As the level rises, the brightness of the screen often cannot rise smoothly along the theoretical gamma curve, but there are various low-light display problems such as steps, jumps, and even reversals, which make the dark parts of the screen perform poorly, such as human hair, dark suits, etc. Loss of detail in textures and stages of dimly lit shows, resulting in severe image artifacts

In addition, due to the error existing in the gamma curve that cannot be calibrated, the existing bright color consistency correction technology can only ensure that the bright color of a certain gray scale of the LED display is consistent, but cannot ensure that the bright colors of all gray scales are consistent, that is, the LED display is all gray Level bright color consistency correction has not been practical

Since the determination of the gamma curve is essentially the determination of a set of brightness values, 3×255 brightness measurements and subsequent data processing are required, with many procedures, cumbersome steps, high error probability, long time-consuming, and low-gray-scale brightness measurement The requirements for the measurement environment and instruments are too high, and the existing equipment is very expensive. Most companies in the industry have not purchased special equipment for the actual measurement and calibration of the LED screen gamma curve, and do not measure the gamma curve, but only set the gamma based on experience The value is delivered to the user, and the standard pattern of up-down gradient or left-right gradient is displayed on the LED screen, and it is judged whether it is qualified or not through a rough qualitative inspection with the naked eye

When you encounter problems and need to adjust the gamma meter, you also need to modify the values ​​​​one by one based on experience. After visual evaluation, it will inevitably affect the performance of the LED display, and it is difficult to meet the requirements of the end users of the screen.

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