Apparatus and method for projecting laser pattern with reduced speckle noise
US5621529A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Apr 5, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T7/521
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illuminating apparatus is for use with a visual sensory apparatus, for projecting a light pattern onto a surface to be viewed by the sensory apparatus. The illuminating apparatus comprises: a light source; a patterniser for constraining light emitted from the source to produce on the surface, a light pattern having a light interface, the interface having an extended dimension. The light pattern is caused to move relative to the surface, parallel to the extended dimension of the light interface. The pattern may comprise a plurality of extended straight line interfaces, each interface being parallel to the other interfaces of the plurality. Rather than straight, the plurality may be circular and concentric. Rather than a plurality, the pattern may comprise a single straight line or circular light interface. The motion of the light pattern relative to the surface minimizes any speckle pattern that might arise from optical interference, below the degree of speckle that would be presence if the pattern were not moving. The pattern may be made to move by moving the light source, or a mirror or prism interposed in the optical path from the light source to the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.