An experimental ultrahigh-definition color video camera system with 7, 680 (H) x 4, 320 (V) pixels has been developed using four 8-million-pixel CCDs. Each 8-million-pixel CCD with a progressive scanning rate of 60 frames per second has 4, 046 (H) x 2, 048 (V) effective imaging pixels, each of which is 8.4 micron2. We applied the four-imager pickup method to increase the camera's resolution. This involves attaching the CCDs to a special color-separation prism. Two CCDs are used for the green image, and the other two are used for the red and blue images. The spatial image sampling pattern of these CCDs relative to the optical image is equivalent to one with 32 million pixels in the Bayer pattern color filter. The prototype camera attains a limiting resolution of more than 2, 700 TV lines both horizontally and vertically, which is higher than that of an 8-million-pixel CCD. The sensitivity of the camera is 2, 000 lux, F 2.8 at approx. 50 dB of dark-noise level on the HDTV format. This camera system also has a new contour compensation circuit. It suppresses the false color caused by the non-linearity and the pixel-count difference between green and red (or blue). The technique has contributed to the reduction of the camera's signal process circuitry.
