Infrared imager
US4779004A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1987 |
| Grant date | Oct 18, 1988 |
| Priority date | — |
| Expiry date | Aug 4, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/80
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An infrared imager, wherein a transparent gate 14 is separated from a very narrow bandgap semiconductor 106 (such as HgCdTe) by a thin dielectric 15, 62. The gate 14 is biased to create a depletion well in the semiconductor 106, and photo-generated carriers are collected in the well. The gate voltage is sensed to measure the accumulated charge. Preferably the accumulated charge is not sensed directly from the gate, but the gate output is repeatedly averaged with another capacitor, so that the output of the imager is sensed as in average over a number of read cycles, which provides a greatly improved signal-to-noise ratio. Preferably an array of the MIS detection devices is formed in a thin layer of HgCdTe 106, which is bonded to a silicon substrate 107 containing a corresponding array of the averaging capacitors with addressing and output connections, and via holes 16 through the HgCdTe are used to connect each detection device to its corresponding averaging capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.