Optical: systems and elements – Lens – With multipart element
Patent
1995-05-19
1996-10-22
Epps, Georgia Y.
Optical: systems and elements
Lens
With multipart element
G02B 308
Patent
active
055683240
ABSTRACT:
A low-profile transmissive overhead projector employs a folded optical path and an off-axis Fresnel lens condensing system which includes a catadioptric lens element. This lens provides a fast condensing system which allows collimation, dispersion, or concentration of light striking the lens at a high angle of incidence, with efficient transmission to the far edge of the lens. This also enables additional reduction in the OHP base height by allowing the single mirror to be mounted at a flatter angle, with the light source still maintained at a position below (and adjacent) the stage. A novel catadioptric lens design further imparts achromaticity to the element, so that it may be constructed of any material, regardless of its index of refraction. The condensing system may have a single or doublet catadioptric lens.
REFERENCES:
patent: 2003804 (1932-07-01), Falge
patent: 4118761 (1978-10-01), Dey
patent: 4337759 (1982-07-01), Popovich et al.
patent: 4436393 (1984-03-01), Vanderwerf
patent: 4741613 (1988-05-01), Vanderwerf
patent: 4755921 (1988-07-01), Nelson
patent: 4775232 (1988-10-01), Fischbeck et al.
patent: 4859043 (1989-08-01), Carel et al.
patent: 4900129 (1990-02-01), Vanderwerf
patent: 4952053 (1990-08-01), Behr
patent: 4969733 (1990-11-01), Jewison
patent: 5097395 (1992-03-01), Aho et al.
patent: 5150966 (1992-09-01), Nelson
patent: 5161057 (1992-10-01), Johnson
patent: 5317349 (1994-05-01), Vanderwerf
patent: 5453880 (1995-09-01), Vanderwerf
Article entitled "A New Clue to color Correction," published Aug., 1976, in Optical Spectra, pp. 22-24.
Article entitled "Understanding Secondary color," published Jun. 1978, in Optical Spectra, pp. 44-46.
Article entitled "Achromatic and Sharp Real Imaging of a Point by a Single Aspheric Lens," published Oct. 15, 1983, in Applied Optics pp. 3242-3248.
Article entitled "Hybrid Diffractive-Refractive Lenses and Achromats," published Jul. 15, 1988 in Applied Optics; pp. 2960-2971.
Article entitled "Rear Projection System Features Ultra-Slim, 50-Inch Design," published Fall, 1992, in Display Devices, l pp. 34-37.
Article (undated) entitled "Chromatic Dispersion Compensation in a Fresnel Lens by Means of A Diffraction Grating."
SPIE Brochure-"Nonimaaging Optics: Maximun Efficiency Light Transfer"- vol. 1528, Copyright 1991 by the Society of Photo-Optical Instrumentation Engineers.
Fesler Robert M.
Nelson John C.
Vanderwerf Dennis F.
Epps Georgia Y.
Griswold Gary L.
Kirn Walter N.
Lester Evelyn A.
Minnesota Mining and Manufacturing Company
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