Lens driving apparatus for a camera
US4984000A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Nov 3, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B3/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens driving apparatus for use in a camera, which adjusts the focus or the angle of view of a lens by means of a motor driven in accordance with the amount of rotation and the rotational angle of rotational operation member provided on a lens body or a camera body, comprises a first detector for detecting the operational direction and the amount of operation of the rotational operation member and generates an operational direction signal and an amount-of-operation pulse signal, a second detector for detecting the actual amount of driving of the lens and generating a drive pulse signal, a motor driver for rotating the motor in a direction according to the operational direction signal until the difference between the count value of an amount-of-operation pulse and an amount-of-driving pulse becomes 0, and a CPU for detecting pressing of the lens against a drivable end portion, inhibiting driving of the lens in that direction, and changing the resistive force of the operation member when operated, thus alarming that the lens has reached the end, in a case where a generation interval of the drive pulse signal is greater than a predetermined time even if the motor is driven.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.