Displacement information detecting apparatus and doppler velocimeter apparatus
US5483332A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1995 |
| Grant date | Jan 9, 1996 |
| Priority date | — |
| Expiry date | Apr 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/4812
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A doppler velocimeter determines the velocity of an object moving through a beam intersection area by using a doppler frequency obtained by detecting light from the beam intersecting area. The doppler velocimeter includes: a light source; a diffraction grating for diffracting light received from the light source; first and second lens systems for transmitting diffracted light from the diffraction grating to irradiate a portion of a movable object to be examined, the first and second lens systems having the same focal length F; and a detector device for receiving light from the portion of the object irradiated with the light which has been transmitted through the first and second lens systems and for obtaining a doppler signal used for velocity determination. The interval between the first and second lens systems is twice as long as the focal length F. Spherical aberration caused by a portion of the first lens system through which the diffracted light travels is offset by spherical aberration caused by a portion of the second lens system through which the diffracted light travels. This simple construction achieves equidistant interference fringes over the beam intersection area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.