A compact, high-performance HDTV camera with four-CCD chips

A compact, high-performance and yet less-expensive camera is urgently needed to create more diverse and flexible HDTV program productions. In order to meet the demand, we propose a completely new image acquisition 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 number of pixels results in wider dynamic range, higher aperture ratio and low cost. The resolution power is secured by adding one more CCD to the conventional three-CCD system. We succeeded in improving the resolution by introducing spatial pixel offset imaging, in which the two G-CCDs are aligned by one-half pitch of a pixel and one of them is aligned with the R-CCD and the other with the B-CCD. This new method has two major advantages: it prevents resolution degradation caused by chromatic aberration and improves the resolution of colored signals over a wide range. The prototype camera has fully satisfied HDTV quality requirements: limiting resolution 1200 TV lines, sensitivity F5 at 2000 lux, dynamic range 500%, SNR 52 dB. >