Enhancement latitude of civil digital photography system by liquid crystal

摘要

In order to enhance the civil digital photography system's latitude, a kind of new structure is put forward which is made the liquid crystal plate coupled to CCD/CMOS (Charge Coupled Device/Complementary Metal Oxide Semiconductor) sensitive chip in this paper. We call this structure chip is LCCCD (liquid crystal CCD). This new system's key is proximity coupled a high precision HTPS ( Low Temperature Poly-Silicon ) liquid crystal plate on the foundation of current CCD/CMOS chip; each pixel on the liquid crystal plate corresponds with the pixel on CCD/CMOS one by one. They compose the new sensitive photosensitive chip that can control the each pixel's ratio of photoelectric conversion by changing each liquid crystal unit's transmittance. This paper expounds this system's structure as well as various modules' cooperation mode and the process of achieving the aim. Through analysis original image by common camera and the same image by LCCCD camera, these results are obtained: the image is changed directly on the physical level by the new system is much better than produces by post treatment, moreover the system can rectify images by 10bit precision, and the imaging latitude has been enhanced more than 5EV(EV is exposure level).