Encoder device
US5287137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1993 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Feb 3, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/102
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An encoder device of the present invention comprises: PA1 a motor for driving a photographing lens, PA1 a pulse generator operated by a drive force transmitted from the motor to the photographing lens, and generating a coarse pulse signal and a fine pulse signal corresponding to rotation of the motor, PA1 counters for counting the coarse pulse signal and the fine pulse signal, respectively, PA1 a reset device for resetting the number of the coarse pulse signals counted by the counters when the photographing lens reaches a predetermined position, PA1 a motor drive/controller for controlling start and stop of drive of the motor, and PA1 a detector for determing a value related to the driven position of the photographing lens upon halting of the driving of the motor based on the number of the coarse pulse signals counted from the predetermined position for resetting and the number of the fine pulse signals counted after a final one of the coarse pulse signals has been output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.