Apparatus for photometrically detecting an optically focused condition of an optical system
US4711999A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1987 |
| Grant date | Dec 8, 1987 |
| Priority date | — |
| Expiry date | Jan 14, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B23/2407
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for detecting a focused condition of an optical system, in which a light-receiving means arranged at a fixed position corresponding to a focus position photometrically detects a focused condition. A light beam having a definite shape is projected onto an object to be imaged by a light projection means. The reflected light beam is conducted along an optical axis of the optical system, deflected, and detected by the light receiving means for determining whether a focused condition exists. Several embodiments are disclosed for projecting a light spot of high contrast of the object and for detecting a focused condition on the basis of the intensity distribution of light received by the light-receiving means. The apparatus may be applied to an endoscope and other optical systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.