Shutter instrumentation device for detecting the opening and the closing of a camera shutter
US5457514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1994 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Feb 23, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/097
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera having a mechanism to determine the precise times at which a shutter or shutter blinds open or close an aperture. The camera measures the actual time in which shutter blinds pass over the aperture by utilizing a projection unit, positioned on one side of the shutter, to project a signal towards the aperture. A signal receiving unit is placed on the other side of the shutter and receives the signal. The output of the signal receiving unit changes depending on whether the signal projected by the projection unit is blocked by the shutter (when the shutter is closed) or whether the projected signal passes through the aperture. The projection unit and the receiving unit can also be placed on the same side of the shutter, with a reflecting unit placed on the other side of the shutter, with the shutter blinds having a different reflectivity than the reflecting unit. When the shutter blinds are closed, the projected signal is reflected off the shutter blinds and received by the receiving unit. When the shutter blinds are open, the projected signal is reflected from the reflecting unit and received by the receiving unit. The output of the receiving unit is different, depending on w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.