Infrared imaging systems with pseudo AC coupling circuit
US4580051A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 5, 1984 |
| Grant date | Apr 1, 1986 |
| Priority date | — |
| Expiry date | Nov 5, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/23
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A thermal energy imaging system includes an optical system for focusing thermal energy emanating from a scene on an array of bulk semiconductor photodetectors. The detector array outputs electrical signals representative of the impinging thermal energy, a video electronic circuit and a pseudo ac coupling circuit interconnecting the detector array and video electronic circuit for reducing the required dynamic range of the video electronic circuit. The pseudo ac coupling circuit includes first and second electrical paths to an sychronous clamp. The first path includes a switch to the synchronous clamp; the second clamp includes first and second integrator circuits and a switch; the switch is connected to the synchronous clamp. The synchronous clamp includes an amplifier, capacitor and grounded switch. When the switch of the first electrical path is open and the switch of the second electrical path and synchronous clamp are closed, line picture element signals are voltage averaged and stored on the capacitor of the synchronous clamp. When the switch of the first electrical path is closed and the switches of the second electrical path and synchronous clamp are opened, the stored averag…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.