US5100222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen and image display apparatus
Assignee: Canon Inc
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Filing: 1990-07-27
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Granted: 1992-03-31
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Expires: 2010-07-27
Abstract
Abstract A screen is disposed in the position at which an image is formed by an image projector. The screen comprises a transparent sheet having a longitudinal direction and a latitudinal direction, and a fresnel lens surface formed on one surface of the transparent sheet to condense a light beam entered thereinto and emit the condensed light beam, the focal length of the Fresnel lens surface in the longitudinal direction of said transparent sheet being shorter than that in the latitudinal direction of the sheet.
Inventors
- 👤 Nobuo Minoura
- 👤 Katsumi Kurematsu
- 👤 Haruyuki Yanagi
- 👤 Hideaki Mitsutake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:54
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
87 words
A screen to be disposed in the position at which an image is formed by image projection means, said screen comprising: a transparent sheet having a first longitudinal direction and a latitudinal direction; and a Fresnel lens surface formed on said first transparent sheet to condense a light beam entered thereinto and emit the condensed light beam, the focal length of said Fresnel lens surface in the longitudinal direction of said first transparent sheet being shorter than that in the latitudinal direction of said first transparent sheet.
Claim 2
Dependent Claim
87 words
A screen to be disposed in the position at which an image is formed by image projection means, said screen comprising: a transparent sheet having a first longitudinal direction and a latitudinal direction; and a Fresnel lens surface formed on said first transparent sheet to condense a light beam entered thereinto and emit the condensed light beam, the focal length of said Fresnel lens surface in the longitudinal direction of said first transparent sheet being shorter than that in the latitudinal direction of said first transparent sheet.
Claim 3
Dependent Claim
35 words
A screen according to claim 1, wherein said Fresnel lens surface comprises a plural number of concentrical elliptic prisms with the center of the ellipses being eccentric to the center of said first transparent sheet.
Claim 4
Dependent Claim
58 words
A screen according to claim 3, further comprising a second transparent sheet opposed to said first transparent sheet, said second transparent sheet having a Fresnel lens surface formed thereon to condense a light beam entered thereinto and emit the condensed light beam, the longitudinal focal length of said Fresnel lens surface being shorter than the latitudinal focal length.
Claim 5
Dependent Claim
100 words
An image display apparatus comprising: image projection means for projecting an image to be displayed; and a screen disposed in the position at which said image projection means forms an image, said screen comprising a first transparent sheet having a longitudinal direction and a latitudinal direction, and a Fresnel lens surface formed on said first transparent sheet to condense a light beam entered thereinto and emit the condensed light beam, the focal length of said Fresnel lens surface in the longitudinal direction of said first transparent sheet being shorter than that in the latitudinal direction of said first transparent sheet.
Claim 6
Dependent Claim
100 words
An image display apparatus comprising: image projection means for projecting an image to be displayed; and a screen disposed in the position at which said image projection means forms an image, said screen comprising a first transparent sheet having a longitudinal direction and a latitudinal direction, and a Fresnel lens surface formed on said first transparent sheet to condense a light beam entered thereinto and emit the condensed light beam, the focal length of said Fresnel lens surface in the longitudinal direction of said first transparent sheet being shorter than that in the latitudinal direction of said first transparent sheet.
Claim 7
Dependent Claim
37 words
An image display apparatus according to claim 4, wherein said fresnel lens surface comprises a plural number of concentrical elliptic prisms with the center of the ellipses being eccentric to the center of said first transparent sheet.
Claim 8
Dependent Claim
51 words
An image display unit according to claim 5, wherein said image projection means projects a light beam obliquely into said first transparent sheet and said Fresnel lens surface emits a principal ray of the entered light beam while deflecting the ray in the direction substantially normal to said first transparent sheet.
Claim 9
Dependent Claim
60 words
An image display unit according to claim 6, further comprising a second transparent sheet opposed to said first transparent sheet, said second transparent sheet having a Fresnel lens surface formed thereon to condense a light beam entered thereinto and emit the condensed light beam, the longitudinal focal length of said Fresnel lens surface being shorter than the latitudinal focal length.
Claim 10
Dependent Claim
85 words
A screen to be disposed in a position at which an image is projected by an image projector for viewing by a viewer, said screen comprising: a screen having a longitudinal direction and a latitudal direction; and a Fresnel lens, formed on the sheet, for condensing a light beam from the image projector, with a focal length of said Fresnel lens in the longitudinal direction of said sheet being shorter than a focal length of said Fresnel lens in the latitudinal direction of said sheet.
Claim 11
Dependent Claim
85 words
A screen to be disposed in a position at which an image is projected by an image projector for viewing by a viewer, said screen comprising: a screen having a longitudinal direction and a latitudal direction; and a Fresnel lens, formed on the sheet, for condensing a light beam from the image projector, with a focal length of said Fresnel lens in the longitudinal direction of said sheet being shorter than a focal length of said Fresnel lens in the latitudinal direction of said sheet.
Claim 12
Dependent Claim
120 words
An image display apparatus for displaying a predetermined image to a viewer, comprising: a projector for projecting the image; and a screen on which the image is projected, said screen including a sheet having a longitudinal direction and a latitudinal direction, with a Fresnel lens formed on said sheet and having a focal length in the longitudinal direction different from a focal length in the latitudinal direction, and wherein each of the focal lengths of said Fresnel lens is determined so that a first focused position, determined by said screen, of light from said projector in the longitudinal direction is closer to the viewer than a second focal position, determined by said screen, of the light in the latitudinal direction.
Claim 13
Dependent Claim
120 words
An image display apparatus for displaying a predetermined image to a viewer, comprising: a projector for projecting the image; and a screen on which the image is projected, said screen including a sheet having a longitudinal direction and a latitudinal direction, with a Fresnel lens formed on said sheet and having a focal length in the longitudinal direction different from a focal length in the latitudinal direction, and wherein each of the focal lengths of said Fresnel lens is determined so that a first focused position, determined by said screen, of light from said projector in the longitudinal direction is closer to the viewer than a second focal position, determined by said screen, of the light in the latitudinal direction.
Claim 14
Dependent Claim
32 words
An apparatus according to claim 9, wherein the focal length of said Fresnel lens in the longitudinal direction is shorter than the focal length of said Fresnel lens in the latitudinal direction.
Claim 15
Dependent Claim
13 words
An apparatus according to claim 9, wherein said sheet is a transparent sheet.
Claim 16
Dependent Claim
13 words
An apparatus according to claim 10, wherein said sheet is a transparent sheet.
Claim 17
Dependent Claim
18 words
An apparatus according to claim 8, wherein the first position is set in the vicinity of the viewer.
Claim 18
Dependent Claim
18 words
An apparatus according to claim 9, wherein the first position is set in the vicinity of the viewer.
Claim 19
Dependent Claim
18 words
An apparatus according to claim 10, wherein the first position is set in the vicinity of the viewer.
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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) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |