Vari-focal viewfinder optical system
US5495367A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1993 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Oct 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B23/145
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A vari-focal viewfinder optical system which comprises an objective lens system for forming an image of an object to be photographed, reflecting members for erecting the image formed by the objective lens system, an eyepiece lens component for allowing observation of the image formed by the objective lens system, and a lens component which has a positive refractive power and is disposed so as to be settable and removable into and out of an optical path between the reflecting members and the eyepiece lens component, and is configured so as to change observing visual fields by varying a focal length of the eyepiece lens component by using the lens component which has the positive refractive power and is settable and removable into and out of the optical path. This vari-focal viewfinder optical system permits observing images with no strange impression and makes it possible to configure cameras compact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.