US4511211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection screen anchor
Assignee: Iowa State University Research Foundation Inc
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Filing: 1982-12-13
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Granted: 1985-04-16
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Expires: 2002-12-13
Abstract
Abstract A projection screen having spaced apart lateral edges and opposite upper and lower ends that is mounted at its upper end by appropriate support means to a wall and which has a means for releasably magnetically securing the lower end of the screen to the wall. By securing the lower end of the screen to the wall while the upper end of the screen is spaced apart from the wall, the keystone effect that occurs when an overhead projector is used to upwardly project an image onto a vertically hanging screen is eliminated.
Inventors
- 👤 William S. Runyan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:54
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/58; Y; Y10; Y10S; Y10S160/00; Y10S160/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
153 words
A projection screen comprising: a screen having spaced-apart lateral edges and opposite upper and lower ends; support means adapted to be attached to a wall and adapted to support said screen at said lateral edges of said upper end; a pair of elongated magnetic anchor means pivotally secured to said wall and extending upwardly and outwardly therefrom, said anchor means each having adjustment means thereon for selectively adjusting the angle of said anchor means with respect to the wall; and said lateral edges of said lower end of said screen each have a metal cap capable of magnetic engagement with said anchor means whereby, upon adjustment of said anchor means to an angle in nonintersecting relation with the top of the screen, adjustment of said lateral edges of said lower end of the screen longitudinally of said anchor means is operative to adjust the angle of the screen with respect to the wall.
Claim 2
Dependent Claim
153 words
A projection screen comprising: a screen having spaced-apart lateral edges and opposite upper and lower ends; support means adapted to be attached to a wall and adapted to support said screen at said lateral edges of said upper end; a pair of elongated magnetic anchor means pivotally secured to said wall and extending upwardly and outwardly therefrom, said anchor means each having adjustment means thereon for selectively adjusting the angle of said anchor means with respect to the wall; and said lateral edges of said lower end of said screen each have a metal cap capable of magnetic engagement with said anchor means whereby, upon adjustment of said anchor means to an angle in nonintersecting relation with the top of the screen, adjustment of said lateral edges of said lower end of the screen longitudinally of said anchor means is operative to adjust the angle of the screen with respect to the wall.
Claim 3
Dependent Claim
22 words
A projection screen according to claim 1, wherein said metal caps include magnetic material and are releasably magnetically secured to said wall.
Claim 4
Dependent Claim
24 words
A projection screen according to claim 1 wherein said projection screen is raised and lowered by an electric motor having an automatic shut-off switch.
Claim 5
Dependent Claim
37 words
A projection screen according to claim 3 wherein said metal caps of said lower end of said projection screen slide upwardly and off of said anchor means when said electric motor is activated to raise said screen.
Claim 6
Dependent Claim
61 words
A projection screen according to claim 1 wherein said support means support said upper end of said screen away from said wall and said anchor means secure said lower end of said screen closer to said wall than said upper end of said screen, whereupon said screen produces no "keystone" effect when an image is projected upwardly from an overhead projector.
Claim 7
Dependent Claim
164 words
A projection screen, comprising: a screen having spaced-apart lateral edges and opposite upper and lower ends, support means adapted to be attached to a wall and adapted to support said screen at said lateral edges of said upper end, a pair of elongated magnetic anchor means secured to said wall and extending upwardly and outwardly therefrom in nonintersecting relation with the top of the screen, an electric motor operatively connected to said projection screen to raise and lower said screen, said motor having an automatic shut-off switch, said lateral edges of said lower end of said screen each having a metal cap capable of slidable magnetic engagement with said anchor means whereby sliding adjustment of said metal caps longitudinally of said anchor means is operative to adjust the angle of the screen with respect to the wall, said metal caps of said lower end of said screen sliding upwardly and off said anchor means when said electric motor is activated to raise said screen.
Claim 8
Dependent Claim
164 words
A projection screen, comprising: a screen having spaced-apart lateral edges and opposite upper and lower ends, support means adapted to be attached to a wall and adapted to support said screen at said lateral edges of said upper end, a pair of elongated magnetic anchor means secured to said wall and extending upwardly and outwardly therefrom in nonintersecting relation with the top of the screen, an electric motor operatively connected to said projection screen to raise and lower said screen, said motor having an automatic shut-off switch, said lateral edges of said lower end of said screen each having a metal cap capable of slidable magnetic engagement with said anchor means whereby sliding adjustment of said metal caps longitudinally of said anchor means is operative to adjust the angle of the screen with respect to the wall, said metal caps of said lower end of said screen sliding upwardly and off said anchor means when said electric motor is activated to raise said screen.
Claim 9
Dependent Claim
36 words
The projection screen of claim 6 wherein said anchor means is pivotally secured to said wall and has an adjustment means thereon for selectively adjusting the angle of said anchor means with respect to said wall.
Claim 10
Dependent Claim
61 words
A projection screen according to claim 6 wherein said support means support said upper end of said screen away from said wall and said anchor means secure said lower end of said screen closer to said wall than said upper end of said screen, whereupon said screen produces no "keystone" effect when an image is projected upwardly from an overhead projector.
References Cited (Backward Citations)
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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) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |