Image self-calibration method and device for LCD displays

An image self-calibration device for LCD displays, comprising a front optical sensor disposed in front of an LCD display panel and coupled to a calibration unit, and a calibration reference device disposed in a middle of the LCD display, and the calibration reference device and the display are connected to a computer, and the calibration unit is employed to calibrate the gray scale level and color temperature of the display, based on data measured by the front optical sensor, and the calibration reference device is employed to pre-calibrate the front optical sensor, wherein the calibration unit and the calibration reference device calibrate the front optical sensor as following:

• set up the calibration reference device in front of the display;
• connect the display and the calibration reference device to the computer;
• display a test screen on the display, and the calibration reference device measures the coordinates x and y of chrominance space and luminance Y and stores a first measured data on the computer, and the front optical sensor measures the display and stores a second measured data;
• enter the first measured data obtained by the calibration reference device into a relation equation of the chrominance space and color stimulus to get color stimulus;
• establish a transfer matrix between the second measured data obtained by the front optical sensor and the color stimulus obtained to get a transfer matrix coefficient;
• display other test screens on the display and measure them by the front optical sensor to obtain a third measured data, and then convert the third measured data into coordinates of chrominance space and luminance, following the converting, compare them with the first measured data obtained by the calibration reference device, and after the comparing, when the difference between them is smaller than a margin of error, Delta E (2000)<5, the calibration is successful, and the Delta E (2000) is indicated to be a standard unit of measurement defined in 2000 year by CIE for presenting the color difference, the CIE is the international commission on illumination.