Partially light-controlled imaging system based on High Temperature Poly-Silicon Thin Film Transistor-Liquid Crystal Display

Abstract

A partially light-controlled imaging system is proposed as a novel device. It is used to improve the imaging quality at the illumination of 1.979 x 10(5)lx by means of mitigating image contrast. It consists of a High Temperature Poly-Silicon Thin Film Transistor-Liquid Crystal Display (HTPS TFT-LCD), which is set between the lens and CCD and is coupled with CCD by the optical fiber taper. The transmittance of pixelated LCD can be controlled by Field-Programmable Gate Array to realize the partially light-controlled and thus dynamic range of the imaging system can be extended. Samples of indoor objects and outdoor license plate are photographed by the prototype imaging system under strong light. The imaging results of this novel system are satisfactory with better restored details, compared with the photos taken by normal CCD camera (WAT-231S2) which uses aperture and shutter to control the overall light intensity.