Method of controlling power source of camera
US6519419B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2001 |
| Grant date | Feb 11, 2003 |
| Priority date | — |
| Expiry date | Jul 30, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a camera having an LCD and a clock device, a power source consists of a battery and a booster circuit. When a power switch button is pressed, the camera moves to an ON mode including a drive mode and a standby mode. In the drive mode, the booster circuit is continuously turned on to supply voltage of a predetermined high level. In the standby mode, the booster circuit is intermittently turned on to output voltage of between the predetermined high level and a minimum display voltage level that is necessary for the LCD to keep its display density in a proper range. The booster circuit is normally turned off in an OFF mode. But if the battery voltage goes below a reset level below which a clock device of the camera cannot work, the booster circuit is intermittently turned on in the OFF mode, to boost the battery voltage up above the reset level and drive the clock device by the output voltage of the booster circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.