Safety shut-off protection system
US4960988A · kind A · utility
20Cited by
3References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1989 |
| Grant date | Oct 2, 1990 |
| Priority date | — |
| Expiry date | Mar 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/40
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A safety shut-off protection system is provided for a light responsive system such as video cameras, image intensifiers, thermal imagers, or the like. The light responsive system further includes several series-connected, normally-closed, light responsive photoelectric Darlington safety switches. These safety switches are located to receive light along with the light responsive systems. Light exceeding a threshold intensity impinging on any one of the Darlington safety switches causes such a switch to operate to deactivate the light sensitive system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.