A charge summation 1/3-inch CCD image sensor with 85 dB dynamic range

A 160-kpixel 1/3-in CCD (charge coupled device) image sensor is described based on signal charge summation of four pixels, predicted by computer simulation to realize a wide dynamic range. The device, called a preprocessing CCD, has 85 dB dynamic range and 16- mu m/sup 2/ optical aperture area unit pixel. The pixel size of this device is effectively the same as that of a 1-in optical-format 2-Mpixel CCD image sensor. Using the configuration, the vertical and horizontal CCD register-drive frequencies are one-half and a one-quarter, respectively, those of the conventional CCD. A schematic diagram of this device is shown. The image area has 333 (H)*494 (V) pixels and measures 4.86 (H)*3.66 (V)mm/sup 2/. The pixel is 15.67 (H)*7.5 (V) mu m/sup 2/. The vertical shift register consists of a four-phase CCD driven by a 7.9-kHz clock. The horizontal shift register uses a single two-phase CCD driven by a 31.6-MHz clock.<>