Method of photoelectric detection with reduction of remanence of a phototransistor, notably of the NIPIN type
US4952788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1989 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Oct 6, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/548
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The disclosure concerns photosensitive matrices, and especially those using NIPIN or PINIP type phototransistors made of amorphous silicon. To prevent problems of remanence, due to the collecting of holes in the base after an illumination stage, it is proposed to follow the step for reading the illumination signal by a remanence erasure step in which the phototransistor is made conductive in forward or reverse bias, so as to inject, into the base, electrons which will eliminate the holes by recombination. Switching on by reverse bias proves to be more efficient than switiching on by forward bias. The invention is applicable notably to a matrix structure of rows and columns of photosensitive sites in which each site is formed by a NIPIN transistor made of amorphous silicon in series with a reading diode that may be put into reverse conduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.