Apparatus for and method of reducing or eliminating interference effects in a light tunnel illuminator
US6554464B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2000 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Feb 16, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/09
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light tunnel (24) comprising a hollow light tunnel body (30) or a solid light tunnel body (80) having a central axis (A1 or A2), a reflective surface (42 or 84) facing the axis, and an output end (54 or 94) having an edge (60 or 106) with a chamfered surface (120 or 130) formed on the edge. The chamfered surface is designed to alter the reflective properties of the reflective surfaces of the light tunnel body near the output end so as to reduce or eliminate edge ringing from the light tunnel body edge. In the case of a knife-edge (340) placed at the output end of the light tunnel body, knife-edge ringing is eliminated by providing a light source (310) in the form of a laser with a large number of spatial modes (M2>30). The present invention is expected to be most useful in cases where time-averaging or other interference-eliminating means prove impossible or impractical, such as with applications requiring only one or a few high-irradiance light pulses that need to uniformly irradiate a workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.