US6239907B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rear projection screen using birefringent optical film for asymmetric light scattering
Assignee: 3M Innovative Properties Co
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Filing: 1999-09-03
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Granted: 2001-05-29
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Expires: 2019-09-03
Abstract
Abstract A dispersing element for a rear projection screen assembly is sensitive to the polarization of the light passing through the element. In particular, the element disperses light having a first polarization differently from light having a second polarization orthogonal to the first polarization. The dispersing element may be aligned with a polarization axis neither parallel nor perpendicular to the polarization of the light passing through the element. The dispersing element may also be employed with a polarizer to remove unwanted light that propagates through the dispersing element. The dispersing element may also be rotatably mounted relative to a polarized light source so as to vary the angle between the polarization axis of the element and the polarization direction of the light.
Inventors
- 👤 Richard C. Allen
- 👤 Jeffrey C. Chang
- 👤 William W. Merrill
- 👤 Robert S. Moshrefzadeh
- 👤 Michael F. Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:07
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62; G03B21/625; G02; G02B; G02B27/00; G02B27/28; G02B27/283; G02B3/00; G02B3/02; G02B3/08; G02B5/00; G02B5/02; G02B5/0205; G02B5/021; G02B5/0273; G02B5/0294; G02B5/30; G02B5/3025; G02B5/3033
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
101 words
A rear projection system, comprising a light source, projecting light having a polarization parallel to a source polarization direction; a transmission screen disposed to receive light from the light source, the transmission screen having a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first polarization axis, an angle between the first polarization axis and the source polarization direction being selected to be greater than 0° and less than 90°.
Claim 2
Dependent Claim
101 words
A rear projection system, comprising a light source, projecting light having a polarization parallel to a source polarization direction; a transmission screen disposed to receive light from the light source, the transmission screen having a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first polarization axis, an angle between the first polarization axis and the source polarization direction being selected to be greater than 0° and less than 90°.
Claim 3
Dependent Claim
29 words
A rear projection system as recited in claim 1 , wherein the light source is an image light source projecting an image of polarized light towards the transmission screen.
Claim 4
Dependent Claim
77 words
A rear projection system as recited in claim 1 , wherein the scattering transmission screen includes a polymeric matrix layer embedded with discrete bodies, a difference in refractive index between the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the first scattering axis being different from a difference in refractive index between the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the second scattering axis.
Claim 5
Dependent Claim
17 words
A rear projection system as recited in claim 2 , wherein the polymeric matrix layer is birefringent.
Claim 6
Dependent Claim
16 words
A rear projection system as recited in claim 2 , wherein the discrete bodies are birefringent.
Claim 7
Dependent Claim
20 words
A rear projection system as recited in claim 2 , wherein the discrete bodies are formed from a polymeric material.
Claim 8
Dependent Claim
22 words
A rear projection system as recited in claim 2 , wherein the discrete bodies are aligned substantially parallel to a common axis.
Claim 9
Dependent Claim
55 words
A rear projection system as recited in claim 1 , wherein a first viewing angle defined for light scattered, in the first scattering distribution, in a direction along the first polarization axis is different from a second viewing angle for light scattered, in the first scattering distribution, in a direction along the second polarization axis.
Claim 10
Dependent Claim
54 words
A rear projection system as recited in claim 1 , wherein the transmission screen further includes a second scattering layer disposed to scatter light passing through the first scattering layer, the second scattering layer having a third scattering distribution that is independent of a polarization direction of light passing through the second scattering layer.
Claim 11
Dependent Claim
40 words
A rear projection system as recited in claim 1 , wherein the transmission screen further includes a diffusing surface provided on a layer of the transmission screen to diffuse light passing through the diffusing surface from the image light projector.
Claim 12
Dependent Claim
40 words
A rear projection system as recited in claim 1 , further comprising a Fresnel lens on an input side of the transmission screen, facing the light source, to change divergence of light reaching the transmission screen from the light source.
Claim 13
Dependent Claim
60 words
A rear projection system as recited in claim 1 , wherein the transmission screen further includes a polarizer layer oriented to transmit light transmitted through the first scattering layer, which is polarized parallel to the source polarization direction, and to prohibit transmission of light transmitted through the first scattering layer and which is polarized perpendicular to the source polarization direction.
Claim 14
Dependent Claim
36 words
A rear projection system as recited in claim 1 , wherein the transmission screen is rotatable and the angle between the first polarization axis and the source polarization direction is rotatably selectable between 0° and 90°.
Claim 15
Dependent Claim
111 words
A rear projection system, comprising a light source, projecting light having a polarization parallel to a source polarization direction; and a transmission screen disposed to receive light from the light source, the transmission screen including a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first polarization axis, the transmission screen also including a polarizing layer oriented to transmit light polarized parallel to the source polarization direction, and to prohibit transmission of light polarized perpendicular to the source polarization direction.
Claim 16
Dependent Claim
111 words
A rear projection system, comprising a light source, projecting light having a polarization parallel to a source polarization direction; and a transmission screen disposed to receive light from the light source, the transmission screen including a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first polarization axis, the transmission screen also including a polarizing layer oriented to transmit light polarized parallel to the source polarization direction, and to prohibit transmission of light polarized perpendicular to the source polarization direction.
Claim 17
Dependent Claim
29 words
A rear projection system as recited in claim 14 , wherein the light source is an image light source projecting an image of polarized light towards the transmission screen.
Claim 18
Dependent Claim
27 words
A system as recited in claim 14 , wherein the first scattering layer substantially specularly transmits light having a polarization direction perpendicular to the source polarization direction.
Claim 19
Dependent Claim
75 words
A system as recited in claim 14 , wherein the scattering transmission screen includes a polymeric matrix layer embedded with discrete bodies, a difference between refractive indices of the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the first scattering axis being different from a difference between refractive indices of the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the second scattering axis.
Claim 20
Dependent Claim
15 words
A system as recited in claim 17 , wherein the polymeric matrix layer is birefringent.
Claim 21
Dependent Claim
14 words
A system as recited in claim 17 , wherein the discrete bodies are birefringent.
Claim 22
Dependent Claim
18 words
A system as recited in claim 17 , wherein the discrete bodies are formed from a polymeric material.
Claim 23
Dependent Claim
20 words
A system as recited in claim 17 , wherein the discrete bodies are aligned substantially parallel to a common axis.
Claim 24
Dependent Claim
18 words
A system as recited in claim 14 , wherein dispersion of light transmitted through the screen is asymmetric.
Claim 25
Dependent Claim
52 words
A system as recited in claim 14 , wherein the transmission screen further includes a second scattering layer disposed to scatter light passing through the first scattering layer, the second scattering layer having a third scattering distribution that is independent of a polarization direction of light passing through the second scattering layer.
Claim 26
Dependent Claim
37 words
A system as recited in claim 14 , wherein the transmission screen further includes a dispersing surface provided on a layer of the transmission screen to disperse light passing through the dispersing surface from the light source.
Claim 27
Dependent Claim
40 words
A system as recited in claim 14 , further comprising a Fresnel lens positioned on an input side of the transmission screen, facing the light source, to change divergence of light reaching the first scattering layer from the light source.
Claim 28
Dependent Claim
32 words
A system as recited in claim 14 , wherein an angle between the first polarization axis and the source polarization direction is selected to be greater than 0° and less than 90°.
Claim 29
Dependent Claim
113 words
A display device, comprising: a light source, projecting light having a polarization parallel to a source polarization direction; and a transmission screen disposed to receive light from the light source, the transmission screen having a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first scattering axis, the first scattering layer being rotatably mounted in the display device; wherein rotation of the first scattering layer results in a variation of an angle between the first polarization axis and the source polarization direction.
Claim 30
Dependent Claim
113 words
A display device, comprising: a light source, projecting light having a polarization parallel to a source polarization direction; and a transmission screen disposed to receive light from the light source, the transmission screen having a first scattering layer with a first scattering distribution for light having a polarization parallel to a first screen polarization axis and a second scattering distribution for light having a polarization parallel to a second screen polarization axis orthogonal to the first scattering axis, the first scattering layer being rotatably mounted in the display device; wherein rotation of the first scattering layer results in a variation of an angle between the first polarization axis and the source polarization direction.
Claim 31
Dependent Claim
76 words
A display device as recited in claim 27 , wherein the first scattering layer includes a polymeric matrix layer embedded with discrete bodies, a difference between refractive indices of the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the first polarization axis being different from a difference between refractive indices of the discrete bodies and the polymeric matrix layer for light having a polarization parallel to the second polarization axis.
Claim 32
Dependent Claim
51 words
A display device as recited in claim 27 , wherein the transmission screen further includes a second scattering layer disposed to disperse light passing through the first scattering layer, the second scattering layer having a third scattering distribution that is independent of polarization of light passing through the second scattering layer.
Claim 33
Dependent Claim
39 words
A display device as recited in claim 27 , wherein the transmission screen further includes a dispersing surface provided on a layer of the transmission screen to disperse light passing through the dispersing surface from the image light projector.
Claim 34
Dependent Claim
40 words
A display device as recited in claim 27 , further comprising a Fresnel lens on an input side of the transmission screen, facing the light source, to change divergence of light reaching the first scattering layer from the light source.
Claim 35
Dependent Claim
29 words
A rear projection system as recited in claim 27 , wherein the light source is an image light source projecting an image of polarized light towards the transmission screen.
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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) | 2004-05-28 | 2004-11-27 | 2005-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-28 | 2008-11-27 | 2009-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-28 | 2012-11-27 | 2013-05-29 | $7700.00 | Window Closed / Lapsed |