Optical data recording circuit for a film camera
US6038408A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1999 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Feb 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B17/245
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical data recording circuit includes an optical recording device normally illuminated from a camera battery means in conjunction with initiation of flash illumination in the camera flash illumination circuit. The data recording circuit includes a first charging circuit path having a charging diode and an auxiliary charge storage capacitor for maintaining a charge voltage substantially equal to battery no-load voltage. The optical recording device, typically an LED, is connected to the charge voltage point of the first circuit and, through a switch device to a return terminal of the battery. When the switch device is closed in conjunction with initiating flash illumination, the LED is illuminated by the battery through the charging diode of the first circuit path. If, however, load on the battery from another circuit, such as the flash charging circuit, causes battery voltage to drop below a level needed to effect illumination of the recording device, the auxiliary storage capacitor charge voltage operates to effect illumination of the recording device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.