Title :
A 1/2-in 1.3 M-pixel progressive-scan IT-CCD for digital still camera applications
Author :
Yamada, Toru ; Hatano, Keisuke ; Morimoto, Michihiro ; Furumiya, Masayuki ; Nakashiba, Yasutaka ; Uchiya, Satoshi ; Tanabe, Akihito ; Kawakami, Yukiya ; Nakano, Takashi ; Kawai, Shin´ichi ; Suwazono, Shinobu ; Utsumi, Hiroaki ; Katoh, Satoshi ; Syohji, Da
Author_Institution :
Silicon Syst. Res. Lab., NEC Corp., Kanagawa, Japan
fDate :
2/1/2001 12:00:00 AM
Abstract :
A 1/2-in 1.3 M-pixel progressive-scan interline-transfer charge-coupled-device (IT-CCD) image sensor has been developed for small, low-power mega-pixel digital still cameras (DSCs). The pixel size as small as 5 μm square makes small-size progressive-scan IT-CCD (8.3×7.1 mm2) for the SXGA format. A two-phase-drive horizontal-CCD with phosphorus-implanted storage regions helps reduce the driving voltage to 2.5 V, resulting in the power consumption of the device being as low as 146 mW. A new source-follower amplifier with separate p-well driver transistors achieves 12% higher gain than that obtained using a conventional amplifier. An overflow drain with a self-adjusting potential barrier can instantly remove superfluous charges in vertical-CCDs just before an exposure period, which enables DSCs to perform such functions as quick auto-focusing and dark-current removal. New dual operation modes for still and motion pictures can provide not only high-resolution color signals in a 15-frame/s 1050-line progressive mode but also wide-dynamic-range color signals in a 30-frame/s 525-line progressive mode. The latter mode employs a pixel-exchange-and-mix readout operation that helps halve the number of scanning lines with no loss in sensitivity and color information
Keywords :
CCD image sensors; cameras; low-power electronics; 0.5 in; 1.3 Mpixel; 146 mW; 2.5 V; H-CCD; PST-HCCD; SA-OFD; SXGA format; V-CCD; auto-focusing; dark current removal; dynamic range; high-resolution color signal; low-power digital still camera; p-well driver transistor; pixel-exchange-and-mix readout operation; progressive-scan IT-CCD image sensor; source-follower amplifier; Charge coupled devices; Costs; Digital cameras; Driver circuits; Energy consumption; Laboratories; Motion pictures; National electric code; Optical amplifiers; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
