Overhead projector
US4968134A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1989 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Jun 16, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S353/03
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An overhead projector comprises, a main body, a light source disposed in the main body for emitting a light, a Fresnel lens disposed on an upper surface of the main body, an internal mirror for reflecting the emitted light toward the Fresnel lens, disposed rotatably in the main body such that a portion of the internal mirror is protruded from a bottom of the main body to an outside of the main body upon a use of the projector and is accommodated in the main body upon a non-use of the projector, an arm connected with the main body at one longitudinal end thereof, a projection lens held by the other longitudinal end of the arm for focusing the reflected light which has passed through the Fresnel lens and an original for a projection placed on the Fresnel lens, and a projection mirror for directing the focused light from the projection lens toward a screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.