Camera shutter having an electronic timing device
US4057812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1976 |
| Grant date | Nov 8, 1977 |
| Priority date | — |
| Expiry date | Apr 14, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/083
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera shutter that has an electronic timing device and a photo-electric resistor and associated capacitor timing circuit; a charge starting contact is actuatable to commence the timing circuit action, and an electro-magnetically actuated locking device energized by the timing circuit to hold the shutter blade system open for the duration of the exposure time as determined by the photo-electric resistor. In addition, a mechanical device is provided which acts to delay the opening movement of the driving mechanism of the shutter blade system after actuation of the contact by an amount to compensate for the time taken by the electro-magnetic locking device to move to an unlocking position after the magnet thereof is de-energized by the timing circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.