Exposure control device having a plurality of light detecting areas
US5677733A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1994 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Feb 1, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/71
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An exposure control device having a light measuring area setting circuit which sets a light measuring area on an image sensing plane, a discriminating circuit which discriminates from each other varied states of the image sensing plane through video signal parts corresponding to the inside and the outside of the light measuring area and an exposure compensating circuit which compensates the state of exposure to light is arranged to shift the set position of the light measuring area to trace an object's image at least when the exposure compensating circuit is in operation. The operating modes of the device includes a first light measuring mode in which a quantity of light is measured on the basis of the average video signal level of the whole image sensing plane, a second light measuring mode in which the light quantity is measured with weight attached to a video signal part obtained from the inside of the light measuring area, and a third light measuring mode in which the light quantity is measured with weight attached to the video signal of the light measuring area by shifting the light measuring area to trace the object. The three light measuring modes are adaptively switched fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.