A COMPACT, HIGH-PERFORMANCE HDTV CAMERA WITH 4-CCD CHIPS

A compact, high-performance and yet less-expensive camera is urgently needed to create more diverse and flexible HDTV program productions. I n order to meet the demand, we propose a completely new image acquisit ion system with four CCDs, two CCDs for green light, one for red, and the other for blue. The major purpose of our system is to obtain high- quality pictures with less pixel-number CCDs. The reduction in the num ber of pixels results in wider dynamic range, higher aperture ratio an d low cost The resolution power is secured by adding one more CCD to t he conventional three-CCD system. We succeeded in improving the resolu tion by introducing spatial pixel offset imaging, in which the two G-C CDs are aligned by one-half pitch of a pixel and one of them is aligne d with the R-CCD and the other with the B-CCD. This new method has two major advantages: it prevents resolution degradation caused by chroma tic aberration and improves the resolution of colored signals over a w ide range. The prototype camera has fully satisfied HDTV quality requi rements : limiting resolution 1200 TV lines, sensitivity F5 at 2000lux , dynamic range 500%, SNR 52dB.