Focus correcting apparatus for an auto focus camera
US5493361A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jun 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus correcting apparatus for an auto focus camera having non-TTL type distance measuring means has first memory means for memorizing the amount of deviation of an imaging point from the surface of film caused by the irregularity during lens assembly or the irregularity of the dimensions of lens parts or the refractive indices of lens materials, calculating means for calculating the amount of correction movement of a focusing lens group from the memorized value in the first memory means and the amount of movement of the imaging point per unit amount of movement of the focusing lens group, and lens driving means for driving the focusing lens group on the basis of the final amount of movement consisting of the amount of movement of the focusing lens group calculated from a measured distance value obtained by the non-TTL type distance measuring means, plus the amount of correction movement of the focusing lens group found by the calculation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.