Compact overhead projector
US3979160A · kind A · utility
11Cited by
10References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1975 |
| Grant date | Sep 7, 1976 |
| Priority date | — |
| Expiry date | Mar 3, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/132
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A compact portable overhead projector providing improved uniformity and efficiency of illumination employs an off-focus light source within a truncated light-diffusing ellipsoidal reflector in conjunction with an off-focus aperture plate adjacent the open end of the reflector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.