Application of industrial camera in point-by-point correction technology of LED electronic display
Since the chromaticity of the LED will change significantly with the current change, PWM pulse width modulation is generally used to adjust the brightness of the LED.
The chromaticity and brightness correction of the pixel is achieved by adjusting the red, green and blue components of the point respectively. For each pixel to be corrected, a 3*3 correction coefficient matrix is required to multiply it. The LED is driven by the pulse width corresponding to the correction coefficient, so that the brightness and chromaticity of the entire display screen can be highly consistent.
The LED point-by-point correction system based on industrial cameras can measure multiple pixels at a time. The measurement process is as follows:
(1) Use a standard light source to calibrate the camera and lens.
(2) Using an industrial camera to image multiple pixels on the display screen.
(3) The user sets the corrected target value, including the brightness of the white screen, the chromaticity of the red component, the green component and the blue component.
(4) The host software locates the pixels, and calculates the luminance and chromaticity values of each pixel according to the obtained image.
(5) The host software calculates the correction coefficient matrix of each point.
(6) Send the correction coefficient matrix to the display screen, and the display screen performs matrix operation for each point to realize point-by-point correction.