Power focus device in a camera
US4864344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Sep 5, 1989 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A power focus device in a camera has a manually rotatively operated focus ring, a lens driving drive source for driving a focusing lens, and a pulse generating device operatively associated with the rotation of the focus ring to generate a pulse signal conforming to the amount of rotation of the focus ring. A focus ring rotation direction detecting device detects the direction of rotation of the focus ring from the pulse signal, a focus ring rotation amount detecting device detects the amount of rotation of the focus ring from the pulse signal, and a drive direction setting device sets the direction of drive of the lens driving drive source on the basis of the result of the detection in the focus ring rotation direction detecting device. A drive amount setting device memorizes the result of the detection in the focus ring rotation amount detecting device and sets the memorized value as the amount of drive of the lens driving drive source. A drive source control device control the lens driving drive source in accordance with the direction of drive set in the drive direction setting device and the amount of drive set in the drive amount setting device. A reversing device immediately …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.