Doppler velocity meter
US5216478A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1992 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Feb 24, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J11/42
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A Doppler velocity meter has a radiation source for emitting a radiation beam the wavelength of which fluctuates, such as a laser; an optical system for directing the radiation beam to an object at an incident angle .theta. and a detector for detecting scattered beam generated from the object by directing the radiation beam. The optical system has a diffraction grating which serves to change the incident angle .theta. in accordance with a change in the wavelength .lambda. of the radiation beam in such a manner as to maintain the value of sin .theta./.lambda. substantially constant. The velocity meter can accurately detect the velocity of movement of the object regardless of any change in the wavelength .lambda., because the diffraction grating serves to substantially compensate for any change in the frequency of the scattered beam caused by the change in the wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.