Masking device for use with image projectors
US5121984A · kind A · utility
Inventors
Key dates
| Filing date | Mar 5, 1990 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Mar 5, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S353/03
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A masking device is provided for use with projectors, such as an overhead projector, to selectively block the projection beam that carries an image disposed on a substrate, such as a transparency, for projection onto a viewing screen. The masking device has a framework having preferably guide rails that form slideways receiving a shutter panel. A transparency is aligned by the guide rails and the shutter panel has a leading edge that extends transversely across the aligned transparency so that only the image portion forward of the leading edge is projected. The shutter panel is constructed of a material that inhibits the projectiton beam, but allows the projection to read or view the image portion that is blocked. A base plate of transparent material supports the guide rails and provides a stage on which the transparency may be positioned for projection of the image disposed thereon. Adjustably mounts to retro-fit the masking device on various projectors is described, but the device could be made integrally with the projector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.