Autofocus system
US4414575A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1981 |
| Grant date | Nov 8, 1983 |
| Priority date | — |
| Expiry date | Nov 18, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/38
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an autofocus system in which the image definition of an object to be picked up is detected by image sensor means disposed on a light path of an image-forming optical system and converted into electric signals, and the image-forming position of the image-forming optical system is controlled by using the electric signals, a plurality of electric signals representative of image definitions are obtained from a main image sensor and at least one sub-image sensor which are provided at optically different positions on the light path and subjected to a predetermined logical judgement processing to produce a focus control signal. The position of the image-forming optical system is controlled by the focus control signal. When the sub-image sensor is movably supported and the light path length between the image-forming optical system and the sub-image sensor is varied by changing the position of the sub-image sensor, a signal representative of the position of the sub-image sensor is also subjected to a predetermined logical judgement processing and used for controlling the position of the sub-image sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.