Exposure controller having coring value adapted to the discharge pulse count
US6239840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/73
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An exposure controller comprises a discharge pulse calculation circuit for calculating a discharge pulse count to be output to a solid-state image pickup device within one field period, and a coring circuit for defining the quotient obtained from the discharge pulse count divided by a predetermined setting value and plus 1 as a coring value. In an electronic camera system incorporating an electronic iris, when one discharge pulse changes, the amount of change in the luminance level of an image signal becomes larger as an exposure time becomes shorter, whereby hunting is prevented from occurring at the convergent point of the luminance level, and an exposure controller which is compact and has excellent characteristics can be embodied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.