Optical system vibro-isolating apparatus
US5130729A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1990 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Oct 2, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/005
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An acceleration of a vibration generated in an optical system of, e.g., a camera is detected by a subtracter from output signals of acceleration sensors. An absolute value circuit calculates an absolute value of an acceleration signal from the subtracter. A voltage-controlled oscillator (VCO) generates clocks having a frequency corresponding to a magnitude of the absolute value from the absolute value circuit. The clocks from the VCO are input to a clock terminal of an up/down counter. An ultrasonic motor (USM) drives the optical system in a direction to cancel the vibration. The USM is driven and controlled by a USM control circuit so as to be rotated at a speed corresponding to a count value of the counter. A motor speed detector detects a USM motor speed from output signals of a rotary encoder. An integrator integrates the acceleration signal from the subtracter to obtain a vibration speed. A comparator compares the USM motor speed with the vibration speed and outputs a comparison result to an up/down terminal of the counter, thereby switching between count-up and count-down operations of the counter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.