Closed-loop calibration of RGB LED consumer projectors

Abstract

Recently, Light Emitting Diode (LED) projectors have been widely adopted by consumers. These low-cost compact projectors provide high-brightness and high-resolution images. In addition, the LED bias current can be incrementally adjusted individually for each color LED, i.e. Red, Green, and Blue, which allow a more accurate tuning capability than in traditional light bulb projectors. The variation of current consumption and the projected brightness for each color LED may cause unbalanced color gamut and white point. This paper proposes a closed-loop system that explores LED projectors features by increasing the color gamut range and by permitting dynamic dimming, while white point balance and power consumption are preserved.