Image sensor having photodiodes of improved response to low intensity optical input
US5093727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1991 |
| Grant date | Mar 3, 1992 |
| Priority date | — |
| Expiry date | Mar 15, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/701
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A one dimensional image sensor is disclosed which has a series of photodiodes to be electrically scanned by voltages developed by a sawtooth voltage for generating electric outputs representative of incident optical energy. The scanning voltages for the photodiodes have so far risen beyond their predetermined saturation points with each ramp of the sawtooth voltage, deteriorating the image sensor response to low intensity optical input in particular. This weakness of the prior art is overcome by providing a bias source which generates a periodically varying bias voltage having a series of ramps that are opposite in the direction of progress to the ramps of the sawtooth voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.