Solid state imaging device having transition time relationship for drive signals
US7468750B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2004 |
| Grant date | Dec 23, 2008 |
| Priority date | — |
| Expiry date | Mar 18, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A CMOS sensor has unit pixels each structured by a light receiving element and three transistors, to prevent against the phenomenon of saturation shading and the reduction of dynamic range. The transition time (fall time), in switching off the voltage on a drain line shared in all pixels, is given longer than the transition time in turning of any of the reset line and the transfer line. For this reason, the transistor constituting a DRN drive buffer is made proper in its W/L ratio.Meanwhile, a control resistance or current source is inserted on a line to the GND, to make proper the operation current during driving. This reduces saturation shading amount. By making a reset transistor in a depression type, the leak current to a floating diffusion is suppressed to broaden the dynamic range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.