Optical projector for transparencies and opaques
US4912752A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1988 |
| Grant date | Mar 27, 1990 |
| Priority date | — |
| Expiry date | Mar 21, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/132
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical projector having opaque and transparency operating modes employs a pair of illumination paths, conventional overhead-projection optics, common focus elements, and a large-aperture stage. Oversized objects such as large books or magazines are accommodated by a resilient bottom of a light-constraining hood assembly. A light source is oriented in a manner that eliminates optical or physical interferences between the pair of projection modes. The hood assembly provides novel reflectivity for image intensification in the opaque mode and easy access to the stage for either opaque or transparency projection. Most elements associated with either projection mode can be detached in a unit, leaving solely the remaining mode capability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.