Star field projection apparatus
US7641345B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 2007 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Apr 8, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09B27/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A projection apparatus for generating a moving star field and a cloud-like effect comprises a means for generating a cloud-like effect using at least one non-coherent light source, a means for generating a moving star field using at least one coherent light source and a means for regulating and supplying electric power. The means for generating cloud-like effect using at least one non-coherent light source comprises at least one pair of condenser lenses and an interferential filter wheel rotated by a motor, disposed between at least one pair of condenser lenses. The means for generating the moving star field using a coherent light source comprises a grating wheel rotated by a motor and a diffractive optical element disposed between the at least one coherent light source and the grating wheel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.