Laser speckle velocity-measuring apparatus
US4912519A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1988 |
| Grant date | Mar 27, 1990 |
| Priority date | — |
| Expiry date | Jun 17, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/806
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
There is provided a laser speckle velocity-measuring apparatus comprising: a semiconductor laser to irradiate the light to a moving object; first and second photo sensing devices whose light receiving points are arranged in the moving direction of the objects at a predetermined distance so as to be away from each other; a clock signal generating and control circuit for determining a clock frequency of the clock signal so that the number of clocks of the clock signal is always set to a constant value when the delay time of the photo sensing signal of the second photo sensing device for the photo sensing signal of the first photo sensing device is measured by the clock signals; and an arithmetic operating circuit for counting the clock signals and calculating the length, moving distance, or velocity of the object on the basis of the count value. With this apparatus, the detecting time of the length or velocity of the moving object can be reduced and the measuring processes can be performed in a real-time manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.