Claims
- 1. A mirror-absorber especially adapted for use in the illumination of transmission holograms and comprising a generally rectangular block of light absorbing material having first and second spaced apart faces, with major dimensions substantially equal to or greater than the major dimensions of a transmission hologram to be illuminated, said first face being formed with a parallel array of stepped segments of generally triangular cross-section, each segment being formed on one face with a mirror surface.
- 2. The apparatus of claim 1, in which said mirror surfaces are disposed at 45.degree. to a plane defined by the major dimensions of said first face such that said array comprises a mirror capable of forming a virtual image of a collimated source incident on said mirror surfaces at 0.degree..
- 3. The apparatus of claim 1, in which said mirror surfaces are disposed at an array of angles to a first plane defined by the major dimensions of said first face progressively increasing from 45.degree. at a first end of said array to an angle .theta. at a second end opposite said first end of said array, and in which said segments are progressively curved in respective second planes normal to said first plane from said first end to said second end, said angle .theta. and said curvature being selected to form a virtual image of a point source directed toward said first face.
Parent Case Info
This is a division of application Ser. No. 253,671, filed Apr. 13, 1981, now U.S. Pat. No. 4,429,947.
US Referenced Citations (4)
Non-Patent Literature Citations (1)
Entry |
"Physics for Students of Science and Engineering, Part II, Second Edition, by Halliday and Resnick, Published in 1962, p. 946. |
Divisions (1)
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Number |
Date |
Country |
Parent |
253671 |
Apr 1981 |
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