Image focusing system
US4311366A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1979 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Feb 28, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/24
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention concerns an image focusing system for use in a reprographic camera. To improve the compactness of such a camera, it is known to provide a reflecting element to fold the optical axis extending from an object plane O to the image plane. The known disposition of the reflecting element between a focusing lens system and the image plane necessitates a very large reflecting surface area to satisfy the usual operational requirements of the aperture and field angle. This precludes the use of prisms as the reflecting element, and therefore introduces instability where image reversal is required since a roof mirror, in which the roof angle may drift, must be used. It is proposed to arrange the reflecting element within the focusing lens system, i.e. between two lens assemblies to permit smaller elements, and more particularly interchangeable plane and roof reflector prisms, to be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.