Lens drive apparatus for camera
US4896179A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1989 |
| Grant date | Jan 23, 1990 |
| Priority date | — |
| Expiry date | Jan 11, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens drive apparatus includes a manual operating member. A pulse generator produces pulses as the operating member is moved. Based on a phase shift between the pulses, the speed with which and the direction in which the operating member is moved are detected. Control circuitry delivers a drive signal to a lens driving motor in accordance with the speed of movement signal and the direction of movement signal. A relationship between the speed of movement signal and the drive signal which prevails in the control circuitry can be modified, allowing a high or low level of the drive output to the motor to be selected with respect to the speed of movement and also allowing the speed with which and the direction in which the motor is driven, thus enabling the control circuitry to control the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.