Auto focusing apparatus selectively operable in an ordinary mode and a high speed mode
US6972799B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 1998 |
| Grant date | Dec 6, 2005 |
| Priority date | — |
| Expiry date | Sep 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/73
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A subject image is formed on a CCD through an imaging optical system including a focusing lens. The output from the CCD is input, through an A/D converter and the like, to an AE processor circuit for performing an auto-exposure control processing and an AF processor circuit for obtaining an evaluation value for auto-focusing through a gate circuit. When a release operation is performed, a CPU drives the focusing lens and operates the AF processor circuit and the like at a high speed frame rate if the CPU determines, on the basis of brightness evaluation values from the AE processor circuit, that the brightness of the subject is equal to or higher than predetermined brightness, and drives the focusing lens and operates the AF processor circuit and the like with high precision at an ordinary frame rate if the CPU determines that the brightness of the subject is lower than the predetermined brightness, thereby performing auto-focusing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.