Short throw, oblique incidence, visual transparency projector
OwnerGerald Altmaninventor
Life of this patent
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Abstract
A visual transparency projector has a short throw, oblique incidence catadioptric optical system, capable of enabling (1) a viewing screen and (2) the projector with its operator to be seen by an audience in side-by-side relation.
Claims14
A large copy projector for imaging a visual sheet on a viewing screen, said projector comprising:
- a. Fresnel field lens means having a first axis;
- b. wide angle catadioptric objective reflector means having a second axis;
- c. deflecting mirror means obliquely disposed with respect to said first axis and said second axis;
- d. said objective reflector means establishing a first conjugate surface and a second conjugate surface;
- e. said first conjugate surface including said visual sheet in association with said Fresnel lens means;
- f. said second conjugate surface including said viewing screen;
- g. said deflecting mirror means establishing a folded path involving said first conjugate surface and said second conjugate surface;
- and
- h. lamp means for illuminating said folded path.
A large copy projector for imaging a visual sheet on a viewing screen, said projector comprising a lower housing, an upper casing, and a post extending between and fixed to said housing and said casing, said housing including an upper stage having an upper opening, side panels having a lower opening, a Fresnel lens at said upper opening, said Fresnel lens having an axis, a wide field catadioptric reflector at said lower opening, said catadioptric reflector having an axis, said Fresnel lens having an axis, a deflecting mirror extending obliquely with respect to said axis of said Fresnel lens and said axis of said catadioptric reflector, and a lamp in said casing, said lamp directing diverging illuminating light along an illuminating axis segment that is oblique with respect to said axis of said Fresnel lens, said deflecting mirror establishing a folded optical path for converging imaging light from said Fresnel lens to said catadioptric reflector and for directing diverging imaging light from said catadioptric reflector to a viewing screen.
Dependencies are inferred from the claim text.