Focus controller and optical apparatus using the same
US7801434B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2009 |
| Grant date | Sep 21, 2010 |
| Priority date | — |
| Expiry date | Jan 22, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/673
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A focus controller configured to control focus of an optical element includes a focus state detector configured to detect a focus state based on a contrast value of an image formed by the optical element, and a driving mechanism that moves the optical element including a motor, a position sensor configured to detect a position of a rotor in the motor, and a driving controller configured to select, in accordance with the contrast value, first driving configured to switch an electrization to a coil in accordance with an output of the position senor, or second driving configured to switch the electrization to the coil in the motor in accordance with a determined time interval.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.