Digitally controlled quench flash circuit
US5682562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1996 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | May 16, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/74
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A flash quench controller for a camera having a flash unit includes a light detector for producing a signal, an integrator for integrating the signal from the detector and producing an integrated signal, a comparator for comparing the integrated signal to a reference value, and means for quenching the flash unit when the integrated signal reaches the reference value. By using a pulse signal having a variable pulse width to programmably set the reference value, many different quench time values can be easily established. The flash unit may also be quenched by setting a maximum flash time value. The flash is automatically quenched if this flash time value is reached before the integrated signal level reaches the programmed reference value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.