Camera finder employing holographic view field frames
US4576458A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1984 |
| Grant date | Mar 18, 1986 |
| Priority date | — |
| Expiry date | Apr 2, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B13/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera finder capable of indicating a view field frame for determining the range of photographing and a target mark for showing a desired focus adjusting portion. Interposed between an objective lens and an eye lens in this finder are holograms having recorded thereon view field frames and a target mark. The hologram is irradiated by a reference beam or beams, whereby the view field frame and the target mark are regenerated. In the hologram, there are recorded a first view field frame in which a parallax is corrected in the long-medium distance and a second view field frame in which a parallex is corrected in the short distance. A beam source for regenerating each view field frame is selected in accordance with an object distance, whereby a view field frame corresponding to the object distance is regenerated. The parallax can be corrected as described above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.