Parallel Signal Processing System for a Super High-Resolution Digital Camera

The technology of the digital still camera has recently achieved remarkable progress. The number of pixels in the main stream of consumer-use cameras has reached the 3 million-range, with 5 million the maximum. And for professional-use, the number of pixels has reached the 16 million. Digital still cameras convert signal data generated from these pixel CCD's to luminosity signals and chromaticity signals, which are compressed in conformity with JPEG standards by a signal processing circuit incorporated in the cameras. The increase in the number of pixels results in the increase in the volume of signal processing, as a matter of course. In order to prevent increase in the recording time required for the increased volume of signal processing, the signal processing circuit has been designed and developed to process the signal at a higher rate, with the application of cutting-edge fine-fabrication technology of semiconductors. However, fine-fabrication with a design rule smaller than 0.09 micron needs a vast amount of investment for production, which might lead to a delay in the progress of high-rate processing. Therefore, a new technique of high-rate processing is required that does not depend on smaller scale fine-fabrication. In this paper, we propose a technique for achieving the required high-rate signal processing by the use of parallel connection of the signal processing circuits necessary for handling signals of the digital cameras of high pixel-number CCD's. At the same time, we also report the excellent results obtained with a prototype camera made in accordance with our proposal.