US4418986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear projection screen
Assignee: Mitsubishi Chemical Corp
•
Filing: 1982-03-31
•
Granted: 1983-12-06
•
Expires: 2002-03-31
Abstract
Abstract Provided is a rear projection screen having a front surface receiving light rays from a projector and a viewing surface formed with a lenticulated surface in which lenticules each consisting of a crest, a trough and a flank interconnecting the crest and trough are continuously laid. The flank surface is provided with, on at least a part thereof, a total reflecting surface on which all light rays impinging thereto are reflected and then emanate from the crest through a medium interface thereof.
Inventors
- 👤 Yukio Yata
- 👤 Koichi Inagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:51
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
93 words
A rear projection screen having a viewing side surface, a projection side surface and a medium therebetween and having a plurality of lenticules which are formed on said viewing side surface so as to form a lenticulated surface thereon, said each lenticule comprising a crest and trough portions interconnected by flank portions wherein at least a portion of each flank has a total reflection surface so that all light rays impinging on said flank are reflected by said total reflection surface and emanate through said medium at portions other than said flank portions.
Claim 2
Dependent Claim
93 words
A rear projection screen having a viewing side surface, a projection side surface and a medium therebetween and having a plurality of lenticules which are formed on said viewing side surface so as to form a lenticulated surface thereon, said each lenticule comprising a crest and trough portions interconnected by flank portions wherein at least a portion of each flank has a total reflection surface so that all light rays impinging on said flank are reflected by said total reflection surface and emanate through said medium at portions other than said flank portions.
Claim 3
Dependent Claim
103 words
A rear projection screen having a viewing side surface, a projection side surface and a medium therebetween and having a plurality of lenticules which are formed on said viewing side surface so as to form a lenticulated surface, said each lenticule comprising a crest and trough portions interconnected by flank portions wherein at least a portion of each flank has a total reflection surface so that all light rays impinging on said flank are reflected by said total reflection surface and emanate through the crest portion, and wherein at least one of said crest and trough portions are provided with a lens surface.
Claim 4
Dependent Claim
103 words
A rear projection screen having a viewing side surface, a projection side surface and a medium therebetween and having a plurality of lenticules which are formed on said viewing side surface so as to form a lenticulated surface, said each lenticule comprising a crest and trough portions interconnected by flank portions wherein at least a portion of each flank has a total reflection surface so that all light rays impinging on said flank are reflected by said total reflection surface and emanate through the crest portion, and wherein at least one of said crest and trough portions are provided with a lens surface.
Claim 5
Dependent Claim
24 words
A rear projection screen as claimed in claim 1 or 2 wherein a Fresnel lens is formed on the projecting side of said medium.
Claim 6
Dependent Claim
25 words
A rear projection screen as claimed in claim 1 or 2 wherein said total reflection surface is formed over the entire area of said flank.
Claim 7
Dependent Claim
46 words
A rear projection screen as claimed in claim 1 or 2 wherein the angle α between said total reflection surface and the plane of the projection surface is selected to meet the condition of: α≧90°-(1/2) sin.sup.-1 (1/n) where, n represents the refractive index of said medium.
Claim 8
Dependent Claim
38 words
A rear projection screen as claimed in claim 1 or 2 wherein said medium includes a light diffusion means for diffusing light impinging on the projection surface to increase the angular field of view at the viewing surface.
Claim 9
Dependent Claim
21 words
A rear projection screen as claimed in claim 6, wherein said light diffusion means includes a pigment dispersed in said medium.
Claim 10
Dependent Claim
34 words
A rear projection screen as claimed in claim 1 or 2 wherein a light absorbing layer is formed on the outer side of said reflection surface to improve the contrast of the projected image.
Claim 11
Dependent Claim
46 words
A rear projection screen as claimed in claim 1 or 2 wherein a coating layer of a substance having a refractive index smaller than the refractive index of said medium, and a light absorbing layer are applied on the outer surface of said total reflection surface.
Claim 12
Dependent Claim
15 words
A rear projection screen as claimed in claim 7, wherein said pigment comprises organic material.
Claim 13
Dependent Claim
15 words
A rear projection screen as claimed in claim 7, wherein said pigment comprises inorganic material.
Claim 14
Dependent Claim
22 words
A rear projection screen as claimed in claim 2, wherein both of said crests and troughs are provided with a lens surface.
Claim 15
Dependent Claim
19 words
A rear projection screen as claimed in claim 1 or 2 wherein said trough portions have a concave surface.
Claim 16
Dependent Claim
19 words
A rear projection screen as claimed in claim 1 or 2 wherein said trough portions have a convex surface.
Claim 17
Dependent Claim
20 words
A rear projection screen as claimed in claim 1 or 2 wherein said flank has a generally straight, flat surface.
References Cited (Backward Citations)
CH98590A
Cited
US2510344A
Cited
US2529701A
Cited
GB656651A
Cited
US2738706A
Cited
US2870673A
Cited
US3218924A
Cited
US3257900A
Cited
US3279314A
Cited
US3830556A
Cited
FR2276605A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |