A Chromatic Aberration Correction Method for RGB LED Based on PWM

This paper proposes a chromatic aberration correction method for dimmable multi-channel Red-Green-Blue (RGB) LED based on pulse-width modulation (PWM) in order to eliminate chrominance difference caused by LED aging. An original LED light intensity correction method is proposed according to the fact that color coordinate after aging is only related to the proportion of relative attenuation value of RGB. Through adjusting the PWM duty cycle with respect to the calculation results of proposed correction method, we are able to correct the LED light drift caused by aging. Lastly, an experiment is designed to verify the correction method, and the methodology is further proved to be highly effective. The color difference after applying the proposed chromatic aberration method can be limited within 10% of their original value, while the chromatic difference can be limited within 5% in the half of cases.