Perforation detection device and camera provided with the perforation detection device
US5923912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Apr 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B1/60
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A perforation detection device of a contact piece type to be built into a camera. A detection section of a first contact piece arranged on the rear surface side of a path in which the perforations of a film advance in a film feeding stage is constructed of a metal ball which is a separate member from that of the first contact piece. This metal ball comes in pressure contact with a second contact piece arranged on the front surface side of the film as the perforations pass. When the metal ball faces a perforation of the film, this metal ball comes in contact with both the first and the second contact pieces to provide a continuity between the first and second contact pieces, so that the position of the perforation is detected. In the film feeding stage, the metal ball comes in rolling contact with the film surface. The contact pieces have a very small resistance to the film feed, and it is scarcely possible that the film will be injured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.