A CCD image sensor with 768 × 490 pixels

A ⅔-in 768(H) × 490(V) element interline CCD image sensor has been successfully developed. The device adopts a vertical overflow drain principle, a buried,channel amplifier, three-level polysilicon technology, and 1.5-µm-rule fine-pattern process. The device operates with an NTSC format. The 560 TV lines limiting resolution is obtained in the horizontal direction. No significant loss in transfer efficiency is observed in the horizontal register, even at the 14.32 MHz clock rate. Optimal photosensitivity spectrum response is obtained and the peak response appears at 550 nm. The noise equivalent signal is reduced to 48 electrons, using correlated double sampling. Then, the dynamic range reaches 68 dB. The correlated double sampling, combined with buried-channel amplifier technology is found to be also effective for great reduction in horizontal line noise.