Epi-illumination type projection device
US4386833A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1981 |
| Grant date | Jun 7, 1983 |
| Priority date | — |
| Expiry date | Jun 11, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An epi-illumination type projection device for forming a projected image of an object comprises a body having a screen, first and second projection lens means alternately mounted at a predetermined location on the body to form different projected images on the screen, and an illuminating system having a light source and a main condenser lens provided in the body to supply an illuminating light to the object through the projection lens means when each of the projection lens means is positioned at said predetermined location. Each of the first and second projection lens means has an engaging surface engaged with the body at said predetermined location, a beam splitter disposed obliquely with respect to the optical axis of the projection lens means, a convergent lens group provided on that side of the beam splitter which is adjacent to the object, and an auxiliary condenser lens provided laterally of the beam splitter. The distance between the position whereat the beam splitter of the first projection lens intersects the optical axis and the engaging surface of the first projection lens means is equal to the distance between the position whereat the beam splitter of the second project…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.