Auto-zooming camera apparatus having advanced photographing-magnification setting and displaying functions
US5227831A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1991 |
| Grant date | Jul 13, 1993 |
| Priority date | — |
| Expiry date | Jul 22, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B17/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photographing lens system includes at least one zooming lens. A photometric circuit measures brightness of an object. An exposure calculation circuit calculates an exposure value in accordance with an output from the photometric circuit. A distance measurement circuit measures a distance to the object. A magnification setting circuit determines a photographing magnification of an image of the object to be formed on a film arranging surface. An auto-zooming calculation circuit determines a focal length of the photographing lens system in accordance with an output from the magnification setting circuit, and an output from the distance measurement circuit. A drive circuit drives the zooming lens in accordance with an output from the auto-zooming calculation circuit. A switch is turned on upon a first stroke of a release button. A switching circuit outputs a first value in accordance with a setting value of the magnification setting circuit before the switch is turned on, and outputs a second value according to an output from the exposure calculation circuit after the switch is turned on. A display selectively displays the first and second values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.