Optical data recording circuit for a film camera
US6035141A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1999 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Feb 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical data recording circuit suitably adapted for a low cost, one-time-use camera in which an LED optical recording device is connected via a switch device from one terminal of a battery supply to the base of an oscillator transistor in an oscillator charging circuit. The base of the oscillator transistor is connected via a resistor to the other terminal of the battery supply and via an oscillator charger circuit ON/OFF switch and secondary winding of the charger step-up transformer to the first terminal of the battery supply. The battery is such that its no-load output voltage is sufficient to illuminate the LED. When the switch device is closed to initiate recording of an optical data bit on film in the camera, the LED is illuminated from the battery no-load output voltage if the ON/OFF switch is open and the charging circuit is not running. If the ON/OFF is being held closed while taking a picture, the LED is then illuminated by pulses from the oscillator circuit step-up transformer, preferably by flyback pulses from the transformer secondary winding to the base of the oscillator transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.