A device structure and spatial spectrum for checker-pattern CCD color camera

In order to develop practical color cameras with useful resolution, a novel image processing and charge-coupled device (CCD) structure is proposed which results in shrinking chip size and easing photolithography. The resolution of CCD cameras is limited by the aliasing errors associated with spatially discrete sampling on a photosensing area. The photosensing array arranged in a two-dimensional face-centered rectangular lattice scheme, and the spatial offsetting technique among three CCD's avoid undesirable signal carriers accompanied by aliasing errors. A unique signal processing about vertical correlation of an image is put to use, in order to reduce spurious effects of aliasing. These image processing techniques are theoretically treated on a spectrum space. The photosensing array arranged in a face-centered rectangular lattice scheme is successfully implemented with a zigzag-transfer CCD with checker-pattern sensing sites, which relax some of the lithography requirements and improve image qualities. By means of the zigzag-transfer CCD structure and the image processing, the resolution of color camera has been expanded by a factor of 2.5, compared with that of the conventional CCD cameras employing the same number of pixels. According to the theory, the factor may be increased further up to three or four.