US4364635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slide-screen for back projection
Assignee: Individual
•
Filing: 1981-06-12
•
Granted: 1982-12-21
•
Expires: 2001-06-12
Abstract
Abstract A slide-screen for back projection has a standing and/or suspended frame (1) and a projection surface arranged within it. The projection surface is made double-skinned and consists of a plastics or similar translucent partition (3), which allows through light rays (5) coming from a reflector (4), and a natural or synthetic glass viewing screeen (2) which reflects the impinging light rays (5) in the direction of the translucent partition (3) preventing dissipation of the light.
Inventors
- 👤 Horst Stief
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:04
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
72 words
In a slide-screen for back projection, having a frame and a projection surface arranged within said frame, the improvement which comprises that the projection surface is double-skinned and consists of: (i) a curved translucent partition which lets through light rays coming from a reflector, and (ii) a natural or synthetic glass viewing screen which reflects the impinging light rays in the direction of the translucent partition while preventing the dissipation of light.
Claim 2
Dependent Claim
72 words
In a slide-screen for back projection, having a frame and a projection surface arranged within said frame, the improvement which comprises that the projection surface is double-skinned and consists of: (i) a curved translucent partition which lets through light rays coming from a reflector, and (ii) a natural or synthetic glass viewing screen which reflects the impinging light rays in the direction of the translucent partition while preventing the dissipation of light.
Claim 3
Dependent Claim
19 words
A slide-screen, according to claim 1, wherein the translucent partition is made convexly curved outwards towards the light rays.
Claim 4
Dependent Claim
21 words
A slide-screen, according to claim 1, wherein the translucent partition is concavely curved inwards in the direction of the light rays.
Claim 5
Dependent Claim
14 words
A slide-screen, according to claim 1, wherein the partition is curved in all directions.
Claim 6
Dependent Claim
17 words
A slide-screen, according to claim 1, wherein the translucent partition is a rigid pre-moulded, curved sheet section.
Claim 7
Dependent Claim
27 words
A slide-screen, according to claim 1, wherein the translucent partition consists of a flexible or resilient foil which can be deformed by means of differential air pressure.
Claim 8
Dependent Claim
30 words
A slide-screen, according to claim 6, wherein the convexly curved translucent partition foil is held deformed by means of compressed air or vacuum introduced between it and the viewing screen.
Claim 9
Dependent Claim
33 words
A slide-screen, according to claim 7, wherein the frame is fitted with a valve for introducing compressed air into or raising a vacuum in a space between viewing screen and translucent partition foil.
Claim 10
Dependent Claim
19 words
A slide-screen according to claim 8, wherein the viewing screen and the translucent partition are sealed in the frame.
Claim 11
Dependent Claim
12 words
A slide-screen, according to claim 1, wherein the viewing screen is flat.
Claim 12
Dependent Claim
12 words
A slide-screen, according to claim 1, wherein the viewing screen is curved.
Claim 13
Dependent Claim
35 words
A slide-screen, according to claim 1, comprising between the viewing screen and the translucent partition a matt, tinted or white colored light-inhibiting material such as a foam material, which darkens or brightens the light rays.
Claim 14
Dependent Claim
25 words
A slide-screen according to claim 1, wherein, on the frame adjacent to the translucent partition, there is removably hinged a pivotable mirror for deflected projection.
Claim 15
Dependent Claim
57 words
A slide-screen, according to claim 1, wherein, on the frame adjacent to the translucent partition, there are removably hinged a plurality of partitions which can be opened up to make the slide-screen into a box, and which when not being used can be folded together as a package, running along the frame parallel to the viewing screen.
Claim 16
Dependent Claim
16 words
A slide-screen, according to claim 14, wherein one of the box partitions consists of the mirror.
Claim 17
Dependent Claim
39 words
A slide-screen, according to claim 14, wherein the frame is provided with a peripheral groove for removably securing hinges of the mirror and the partitions, as well as the locking devices of the partitions when folded against the frame.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |