Patent US3704936A successfully refreshed from Google Patents.
US3704936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Achromatic depth-of-field correction for off-axis optical system
Assignee: RCA Corp
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Filing: 1970-03-09
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Granted: 1972-12-05
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Expires: 1990-03-09
Abstract
Abstract Unmodulated, collimated white light is angularly directed to a target reflecting surface which is deformable to represent a subject, and the subject-modulated light reflected from the target surface is directed to a viewing screen by a schlieren optical system including a projection lens and a stop at the focal point of the lens. A prism is located adjacent the real subject-bearing target surface for rendering the apparent target surface parallel, and the light reflected therefrom orthogonal, to the principal plane of the lens and the screen; and for so reducing any color dispersion of the reflected light as to obtain adequate resolution of the image of the subject projected onto the screen.
Inventors
- 👤 Walter Joseph Gorkiewicz
- 👤 John A Van Raalte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:35
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/74
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
234 words
An optical system for projecting an image of a lightreflective subject having an effective principal plane onto a viewing screen, comprising: means for directing a beam of unmodulated, collimated white light onto said subject, said directing means having an optical axis nonorthogonally disposed relative to the effective principal plane of said subject: light-projecting means, including a lens having its principal plane substantially parallel to the plane of said screen and angularly disposed relative to the effective principal plane of said subject, for receiving subject-modulated light reflected from said subject and directing it toward said screen; and means for substantially achromatically orthogonalizing said subject-modulated light relative to the principal plane of said light-projecting lens, said orthogonalizing means comprising a prism located adjacent said subject in the paths of both said beam of unmodulated, collimated white light and said subjectmodulated light, said prism having a rear planar surface closely adjacent to said subject and oriented to be angularly disposed relative to the principal plane of said light-projecting lens, and a front planar surface angularly disposed relative to the principal plane of said light-projecting lens as well as angularly disposed relative to the plane of said rear prism surface, the planes of said front and rear prism surfaces converging at a location on the opposite side of the optical axis of said light-projecting lens from the location of the optical axis of said unmodulated light directing means.
Claim 2
Dependent Claim
234 words
An optical system for projecting an image of a lightreflective subject having an effective principal plane onto a viewing screen, comprising: means for directing a beam of unmodulated, collimated white light onto said subject, said directing means having an optical axis nonorthogonally disposed relative to the effective principal plane of said subject: light-projecting means, including a lens having its principal plane substantially parallel to the plane of said screen and angularly disposed relative to the effective principal plane of said subject, for receiving subject-modulated light reflected from said subject and directing it toward said screen; and means for substantially achromatically orthogonalizing said subject-modulated light relative to the principal plane of said light-projecting lens, said orthogonalizing means comprising a prism located adjacent said subject in the paths of both said beam of unmodulated, collimated white light and said subjectmodulated light, said prism having a rear planar surface closely adjacent to said subject and oriented to be angularly disposed relative to the principal plane of said light-projecting lens, and a front planar surface angularly disposed relative to the principal plane of said light-projecting lens as well as angularly disposed relative to the plane of said rear prism surface, the planes of said front and rear prism surfaces converging at a location on the opposite side of the optical axis of said light-projecting lens from the location of the optical axis of said unmodulated light directing means.
Claim 3
Dependent Claim
42 words
An optical system as defined in claim 1, said prism location placing the effective color-divergence plane for differently colored light ray components emerging from the front prism surface closely adjacent said subject and remote from said principal plane of said light-projecting means.
Claim 4
Dependent Claim
37 words
An optical system as defined in claim 2, said subject being recorded on a deformable film; and said light-projecting means being of the schlieren type having a stop located at the focal point of said light-projecting lens.
Claim 5
Dependent Claim
32 words
An optical system as defined in claim 3, said deformable film being a thin metallic sheet supported in spaced relation to an insulator substrate and constituting an element of a light valve.
Claim 6
Dependent Claim
60 words
An optical system as defined in claim 4, said light valve comprising a cathode ray tube having an envelope including a transparent faceplate enclosing one end of said tube; and an electron gun mounted within said envelope at its other end, said substrate-supported deformable metallic sheet being mounted adjacent said faceplate and constituting a target electrode for said electron gun.
Claim 7
Dependent Claim
18 words
An optical system as defined in claim 5, said prism being cemented to said cathode ray tube faceplate.
Claim 8
Dependent Claim
21 words
An optical system as defined in claim 6, said cathode ray tube faceplate constituting said insulator substrate of said target electrode.
Claim 9
Dependent Claim
26 words
An optical system as defined in claim 2, said prism being a single element device formed of a material having a relatively high color dispersion constant.
Claim 10
Dependent Claim
33 words
An optical system as defined in claim 8, said single element device having a trapezoidal cross-section, and said high color dispersion constant material having an index of refraction of the order of 1.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |