US4652084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection screens for two- or three-dimensional front and back projections
Assignee: Individual
•
Filing: 1985-05-20
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Granted: 1987-03-24
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Expires: 2005-05-20
Abstract
Abstract The present invention provides projection screens for two- or three-dimensional front and back projections in the form of panes or sheets of plastics, when required with delustering lamina and is characterized in that a plastics having noticeably directed transmission, a transmission degree of approximately 1 to 98%, a scattering power of less than 0.3 and a luminous density coefficient of ε 2 =5° of and exceeding 0.5 is used.
Inventors
- 👤 Jurgen Daszinnies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:20
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
54 words
A projection screen for two- or three-dimensional front or back projections comprising at least one pane of plastic wherein the said pane has a noticeably directed transmission degree of approximately 1 to 98%, a scattering power of less than 0.3, and a luminous dinsity coefficient of or exceeding approximately 0.5 at ε 2 =5°.
Claim 2
Dependent Claim
54 words
A projection screen for two- or three-dimensional front or back projections comprising at least one pane of plastic wherein the said pane has a noticeably directed transmission degree of approximately 1 to 98%, a scattering power of less than 0.3, and a luminous dinsity coefficient of or exceeding approximately 0.5 at ε 2 =5°.
Claim 3
Dependent Claim
19 words
A projection screen according to claim 1 wherein said pane has at most a very slight optical activity .
Claim 4
Dependent Claim
23 words
A projection screen according to claim 1 for the front projection, wherein said pane has a transmission degree of approximately 1 to 44%.
Claim 5
Dependent Claim
23 words
A projection screen according to claim 1 for the back projection, wherein said pane has a transmission degree of approximately 45 to 98%.
Claim 6
Dependent Claim
18 words
A projection screen according to claim 1 wherein said pane has a half-angle value of less than 1°.
Claim 7
Dependent Claim
20 words
A projection screen according to claim 1, wherein said pane has a lamina thickness of greater than approximately 1 mm.
Claim 8
Dependent Claim
20 words
A projection screen according to claim 1 wherein said pane has a lamina thickness of at least approximately 1 mm.
Claim 9
Dependent Claim
24 words
A projection screen according to claim 1 wherein said pane comprises a homo or copolymer of methyl methacrylate and an opalizing agent or pigment.
Claim 10
Dependent Claim
19 words
A projection screen according to claim 1, wherein said pane has a lamina thickness of 1 to 30 mm.
Claim 11
Dependent Claim
33 words
A projection screen according to claim 8, wherein said pane has at most a very slight optical activity, a transmission degree of 1 to 44%, and a half angle of less than 1%.
Claim 12
Dependent Claim
33 words
A projection screen according to claim 8, wherein said pane has at most a very slight optical activity, a transmission degree of 45 to 98%, and a half angle of less than 1%.
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) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |