US3706487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photochromic projection system
Assignee: United States Department of the Army
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Filing: 1971-05-04
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Granted: 1972-12-19
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Expires: 1991-05-04
Abstract
Abstract A photochromic projection system wherein indicia appearing on a cathode ray tube, and forming an opaque image on an ultravioletsensitive film positioned against the end face of the cathode ray tube, is imaged upon a viewing screen after passing through a transparent map. A pair of dichroic filters are used both of which reflect yellow and green radiation so that only the yellow and green portion of the radiation from an external illuminating source for the film is reflected to the film. The red and blue portion of the source radiation is transmitted through one of the dichroic filters and reflected from a mirror through the second dichroic filter where it is recombined with the yellow and green light reflected from the face of the cathode ray tube and from the second dichroic filter to provide an image in white light which then is directed through the transparent map onto the viewing screen.
Inventors
- 👤 Salvatore F Laforgia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:33
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/48; G03B21/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
230 words
A projection system comprising an illuminating white light source emanating radiant energy extending from the infrared to the ultraviolet portion of the electromagnetic energy spectrum, a cathode ray tube having a screen which generates ultraviolet radiation in response to impingement thereupon of a positioncontrolled electron beam, said cathode ray tube further having a dichroic coated face plate for reflecting the yellow-green radiation, a photochromic film responding to said ultraviolet radiation for providing a photochromic film image, a pair of dichroic filters which reflect the yellow and green constituents of said radiant energy and transmit the remaining constituents of the radiant energy from said source, means for directing said radiant energy along a first path onto the first of said dichroic filters, said first dichroic filter reflecting the yellow and green constituents of said radiant energy along a second path through the photochromic film image plane to said dichroic coating, said yellow and green constituents reflecting from dichroic coating along a third path to said second dichroic filter, said yellow-green constituents reflecting from said second dichroic filter along a fourth path, the remaining constituents of said energy other than said yellow and green constituents being transmitted through said first dichroic filter along said first path, optic means including a reflector for reflecting said remaining constituents which are transmitted along said first path along said fourth path through said second dichroic filter.
Claim 2
Dependent Claim
230 words
A projection system comprising an illuminating white light source emanating radiant energy extending from the infrared to the ultraviolet portion of the electromagnetic energy spectrum, a cathode ray tube having a screen which generates ultraviolet radiation in response to impingement thereupon of a positioncontrolled electron beam, said cathode ray tube further having a dichroic coated face plate for reflecting the yellow-green radiation, a photochromic film responding to said ultraviolet radiation for providing a photochromic film image, a pair of dichroic filters which reflect the yellow and green constituents of said radiant energy and transmit the remaining constituents of the radiant energy from said source, means for directing said radiant energy along a first path onto the first of said dichroic filters, said first dichroic filter reflecting the yellow and green constituents of said radiant energy along a second path through the photochromic film image plane to said dichroic coating, said yellow and green constituents reflecting from dichroic coating along a third path to said second dichroic filter, said yellow-green constituents reflecting from said second dichroic filter along a fourth path, the remaining constituents of said energy other than said yellow and green constituents being transmitted through said first dichroic filter along said first path, optic means including a reflector for reflecting said remaining constituents which are transmitted along said first path along said fourth path through said second dichroic filter.
Claim 3
Dependent Claim
21 words
The projection system of claim 1 further including a spherical reflector at the focal point of which said source is disposed.
Claim 4
Dependent Claim
31 words
The projection system of claim 1 further comprising a transparent map and image relay lens means for forming the image at said photochromic film plane onto the plane of said map.
Claim 5
Dependent Claim
122 words
The projection system of claim 3 further including field lens means disposed in said first path, said means for directing comprising condensing lens means for imaging said source onto said field lens means, said field lens imaging the aperture of said condensing lens onto said film and onto said reflector, an imaging relay lens means disposed in said fourth path, first relay condensing lens disposed adjacent said film for imaging the aperture of said field lens on said imaging relay lens means, said optic means further including second relay condensing lens means for imaging the aperture of said field lens on said imaging relay lens means, said imaging relay lens means imaging said photochromic film image on the plane of said map.
Claim 6
Dependent Claim
21 words
The projection system of claim 4 further including a spherical reflector at the focal point of which said source is disposed.
Claim 7
Dependent Claim
97 words
The projection system of claim 3 further including a projector assembly imaging both said map and said photochromic film image on said viewing screen and positioned along said fourth path between said map and said viewing screen, said projector assembly comprising third relay condensing lens means for yielding a virtual erect magnified image of both said map and said photochromic film image, and projecting lens means upon which said source is imaged and which projects the two magnified superimposed virtual images of said third relay condensing lens means onto said viewing screen in a short throw distance.
Claim 8
Dependent Claim
97 words
The projection system of claim 4 further including a projector assembly imaging both said map and said photochromic film image on said viewing screen and positioned along said fourth path between said map and said viewing screen, said projector assembly comprising third relay condensing lens means for yielding a virtual erect magnified image of both said map and said photochromic film image, and projecting lens means upon which said source is imaged and which projects the two magnified superimposed virtual images of said third relay condensing lens means onto said viewing screen in a short throw distance.
Claim 9
Dependent Claim
21 words
The projection system of claim 6 further including a spherical reflector at the focal point of which said source is located.
Claim 10
Dependent Claim
176 words
An image projection system comprising an illuminating white light source emitting radiant energy which extends from the infrared to the ultraviolet portion of the electromagnetic energy spectrum, a photochromic film which changes from a normal optically transparent condition to an optically opaque condition in response to controlled impingement thereupon of ultraviolet energy to form a photochromic image, first dichroic filter means for reflecting onto said film the spectral constituents of said radiant energy which have negligible effect on the photochromic properties of said film and for transmitting the remaining constituents of said radiant energy which would adversely affect the photochromic image, second dichroic filter means having the same optical reflection and transmission properties as said first dichroic filter means, optical means for directing said remaining constituents of said radiant energy transmitted by said first dichroic filter means onto said second dichroic filter means for transmission therethrough and means for directing the spectral constituents reflected from said film onto said second dichroic filter means, the energy emanating from said second dichroic filter means being reconstituted white light.
Claim 11
Dependent Claim
176 words
An image projection system comprising an illuminating white light source emitting radiant energy which extends from the infrared to the ultraviolet portion of the electromagnetic energy spectrum, a photochromic film which changes from a normal optically transparent condition to an optically opaque condition in response to controlled impingement thereupon of ultraviolet energy to form a photochromic image, first dichroic filter means for reflecting onto said film the spectral constituents of said radiant energy which have negligible effect on the photochromic properties of said film and for transmitting the remaining constituents of said radiant energy which would adversely affect the photochromic image, second dichroic filter means having the same optical reflection and transmission properties as said first dichroic filter means, optical means for directing said remaining constituents of said radiant energy transmitted by said first dichroic filter means onto said second dichroic filter means for transmission therethrough and means for directing the spectral constituents reflected from said film onto said second dichroic filter means, the energy emanating from said second dichroic filter means being reconstituted white light.
Claim 12
Dependent Claim
39 words
An image projection system according to claim 9 further including a viewing screen and a transparent data-bearing medium, and means for projecting a reconstituted white image of said photochromic film image through said transparent medium and onto said screen.
References Cited (Backward Citations)
US3601470A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |