Lens motor drive device in automatic focusing camera
US4432620A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 9, 1982 |
| Grant date | Feb 21, 1984 |
| Priority date | — |
| Expiry date | Mar 9, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B3/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens motor drive in an automatic focusing camera, in which current corresponding to a degree of focalization of an optical system is supplied to a lens motor in which there is provided a signal forming circuit performing a focalization signal representing the focalization of the optical system, and a focalization deviation signal having a level corresponding to a degree of focalization of the optical system. In addition, there is provided a limiting circuit for providing an output when the level of said focalization signal decreases to an extent that the lens motor cannot continue rotation, and a timing circuit for providing an output when the limiting circuit provides the output for a predetermined period of time. A start pulse generating circuit is also provided for generating a start pulse having a duration long enough to start the lens motor when the output of the timing circuit is provided under the condition that there is an absence of the focalization signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.