US3558802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixable photochromic display apparatus
Assignee: NCR Voyix Corp
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Filing: 1968-01-04
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Granted: 1971-01-26
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Expires: 1988-01-04
Abstract
Abstract An apparatus adapted to receive a filmstrip having a coating of a saccharin-containing photochromic material, includes a central chamber wherein a cathode ray tube imaging means produces reversably opaque image areas on the normally transparent filmstrip. Means are provided to expose the filmstrip to sulfur dioxide gas which affects the photochromic material to render the entire exposed portion of the filmstrip opaque. Means are provided to evacuate the gas and to apply heat which reverses the effect of the gas in those areas that were transparent at the time of exposure. The image areas that were temporarily rendered opaque by the cathode ray tube imaging means remain permanently fixed. The apparatus has a filmstrip inlet chamber and film strip outlet chamber connected to vacuum exhaust system. Leakage of the sulfur dioxide gas from the central chamber is drawn out of the apparatus through the exhaust system before it can escape into the atmosphere.
Inventors
- 👤 William A Stein
- 👤 Robert J Cirillo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:42
CPC Classifications
G; G03; G03B; G03B21/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
175 words
An apparatus for fixing temporary opaque images produced on a transparency that is used in a large screen real-time display system, the transparency being a transparent film coated with a normally transparent photochromic material which is reactive to ultraviolet light exposure to form the temporary image areas, and which is further reactive to certain gas exposure whereby the temporary image areas are fixed, said apparatus comprising: an image-fixing assembly having a central chamber, said assembly having a passageway to allow the film to be drawn through the central chamber, means for directing ultraviolet light rays onto the film in a discriminate pattern to form a desired temporary opaque image area thereon, gas injection means to inject a gas into the central chamber which reacts with the photochromic material to render the entire portion of the film within the central chamber opaque, exhaust means to exhaust the gas from the central chamber, and heating means for heating the film to reverse the gas induced reaction in the nonimage areas with the image areas being permanently opaque.
Claim 2
Dependent Claim
168 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state comprising an image-fixing assembly having a central chamber, said assembly adapted to receive a normally transparent filmstrip having a saccharin-containing ultraviolet light-sensitive photochromic material coated on one side thereof with a portion of said filmstrip positioned within said central chamber, means for discriminately directing ultraviolet light rays onto the filmstrip to produce temporary opaque images thereon, gas injection means for injecting sulfur dioxide gas into the central chamber to react with the saccharin of the photochromic film and render said portion of the filmstrip opaque, exhaust means to evacuate the gas from the central chamber, and heating means for heating said portion of the film to reverse the reaction of the gas in the unimaged areas of the filmstrip for returning it to a transparent state, with the previous temporary images being rendered permanently opaque.
Claim 3
Dependent Claim
92 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 3 wherein the heating means is comprised of means for directing an even flow of hot air over the positioned portion of the photochromic filmstrip, and valve control means for controlling said air flow to heat the film to a temperature of about 70* C. following exposure of the film to the sulfur dioxide gas.
Claim 4
Dependent Claim
85 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 3 wherein the heating means is comprised of a heating plate located within the central chamber, and positioning means for positioning the heating plate from a normal retracted position to an operating position with the heating plate located directly over the gas exposed portion of the photochromic film.
Claim 5
Dependent Claim
125 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 3 wherein a passageway is provided through the image-fixing assembly to allow the film to be drawn through the central chamber and thereby position a different portion of the filmstrip in the central chamber, an inlet chamber and an outlet chamber provided at either side of the central chamber along the passageway, and said exhaust means including a vacuum connected to the inlet and outlet chambers to exhaust sulfur dioxide gas leaking out of the cenTral chamber and thereby avoid escape of the gas into the surrounding atmosphere.
Claim 6
Dependent Claim
84 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 6 wherein the exhaust means includes a first valve control means to produce a vacuum pressure within the inlet and outlet chambers, and said gas injection means includes a second valve control means for injecting a measured volume of gas at a controlled rate into the chamber.
Claim 7
Dependent Claim
157 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 6 wherein said means for directing ultraviolet light rays onto the film to produce the temporary opaque image areas comprises a cathode ray tube, said image-fixing assembly having means to position the cathode ray tube with its face plate located along the pathway whereby the photochromic film is drawn across the outer surface of the face plate and in intimate contact therewith, said face plate comprising a fiber optic plate and a phosphor coated on the inner surface of the fiber optic plate that emits ultraviolet light when bombarded by the electron beam of the cathode ray tube, said fiber optic face plat conducting the ultraviolet light emitted from the phosphor through the face plate and onto the photochromic film.
Claim 8
Dependent Claim
112 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 8 wherein: the image-fixing assembly has a window portion in the central chamber in alignment with the face plate for transmitting a visible light beam into the chamber and toward the face plate, said face plate having a dichroic filter material coated on the outer surface of the fiber optic plate against which the photochromic film is positioned, and said dichroic filter having the properties of transmitting ultraviolet light and of specularly reflecting visible light.
Claim 9
Dependent Claim
137 words
In a real-time display system wherein images temporarily produced on a photochromic film are light projected onto a large size display screen, an apparatus for converting the temporary image to a permanent state as defined in claim 9 wherein a field lens is located in the window portion of the central chamber and including a first light-directing means for directing a visible light beam from a light source through the field lens and onto the face plate of the cathode ray tube where portions of the light beam are blocked by the opaque image areas of the photochromic film, said dichroic filter specularly reflecting the light beam back through the field lens, and a second light-directing means directing the reflected image-bearing light beam into a projection lens for projecting the image onto a large size display screen.
Claim 10
Dependent Claim
107 words
An apparatus as defined in claim 9 wherein the image-fixing assembly includes an inlet chamber and an outlet chamber at either side of the central chamber along the passageway, and gas-impeding seals in the passageway of the assembly at the entrance and exit points of the inlet, central and outlet chambers, the seals being adapted to permit free passage of the film while preventing free flow of the gas therethrough said exhaust means including a vacuum means connected with the inlet and outlet chambers creating negative pressures therein to exhaust the gas leaking past the seals and thereby avoid escape of the gas into the surrounding atmosphere.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |