Automatic focus device and method
US5614983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Jun 29, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic focus state detection device executes focus adjustment by taking environmental factors such as temperature and power source voltage into consideration. The temperature of the camera, the power source voltage of the battery in the camera, and the posture of the camera are detected. Then, lens driving times for six representative points of the driving lens distance are computed. A driving time table is produced, and the defocus amount is detected. Then, based on the updated driving time table, the lens driving time corresponding to the current defocus amount is computed. Finally, the timing for each sequential process from release to start of exposure is determined. In this manner, the driving time is computed by taking the temperature, the power source voltage, and the posture into consideration, and a more accurate estimation of the lens driving time is realized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.