US5691789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single-layer reflective super broadband circular polarizer and method of fabrication therefor
Assignee: Reveo Inc
•
Filing: 1995-10-30
•
Granted: 1997-11-25
•
Expires: 2015-10-30
Abstract
Abstract The present invention relates generally to broadband, reflective circular polarizers and, more particularly, to single layer super broadband, reflective circular polarizers. The polarizers of the present invention are made from a film of material, like a polymer having a cholesteric order, in which a second liquid crystal material, like a nematic liquid crystal, is distributed in a non-linear fashion across the thickness of the film in a plurality of liquid crystal-rich and liquid crystal-depleted sites in the polymer. The resulting polarizers have band passes approaching 2000 nm and reflect circularly polarized light which is either left-handed or right-handed depending on the final spiral structure of the materials utilized. The material of the present invention is fabricated by mixing commercially available polymers having a cholesteric order, a second liquid crystal material and a photoinitiator at a temperature which maintains the mixture in a liquid state. The polymer and the liquid crystal are present in a ratio by weight of 1:2, for example, and the photoinitiator is present in an amount of 0.6% by weight, for example, in the mixture. The heated mixture is then subjected to actinic radiation for a time and at an intensity sufficient to polymerize the polymer or the liquid crystal material or both. Under all polymerizing conditions the segregation rate of the liquid crystal material has to be greater than the polymerization rate of the material being polymerized. The liquid crystal segregates and diffuses, during polymerization, to sites of enlarged pitch in the polymer material from sites of shrunken pitch in the polymer material. Because the actinic light has an exponential intensity distribution due to light attenuation by, for example, light absorption, polymerization occurs in a non-linear fashion resulting in a non-linear distribution of the polymer and the liquid crystal material across the film.
Inventors
- 👤 Le Li
- 👤 Sadeg Mustafa Faris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:06
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02B; G02B5/00; G02B5/30; G02B5/3016; B; B82; B82Y; B82Y15/00; F; F24; F24S; F24S50/00; F24S50/80; E; E06; E06B; E06B9/00; E06B9/24; E06B2009/2464; Y; Y02; Y02E; Y02E10/00; Y02E10/40
Claims Analysis
Total Claims: 74
Claim 1
Independent Claim
55 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of non-linearly varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites said film having a given bandwidth.
Claim 2
Dependent Claim
55 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of non-linearly varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites said film having a given bandwidth.
Claim 3
Dependent Claim
19 words
A broad band polarizer according to claim 1 wherein said non-linearly varying helix pitch is an exponentially varying pitch.
Claim 4
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said material having a cholesteric order is a polymer.
Claim 5
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said material having a cholesteric order is a monomer.
Claim 6
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said material having a cholesteric order is an oligomer.
Claim 7
Dependent Claim
21 words
A broadband polarizer according to claim 1 wherein said at least one said liquid crystal material is a nematic liquid crystal.
Claim 8
Dependent Claim
20 words
A broadband polarizer according to claim 1 wherein said at least one liquid crystal material is a smectic liquid crystal.
Claim 9
Dependent Claim
19 words
A broadband polarizer according to claim 1 wherein said at least one material having a cholesteric order is photopolymerizable.
Claim 10
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said at least one liquid crystal material is photopolymerizable.
Claim 11
Dependent Claim
31 words
A broadband polarizer according to claim 1 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is polymerizable.
Claim 12
Dependent Claim
32 words
A broadband polarizer according to claim 1 wherein the segregation rate of said at least one liquid crystal material is greater than the polymerization rate of whichever of said materials is polymerized.
Claim 13
Dependent Claim
35 words
A broadband polarizer according to claim 1 wherein the segregation rate of said at least one liquid crystal material, is greater than the polymerization rate of said at least one material having a cholesteric order.
Claim 14
Dependent Claim
34 words
A broadband polarizer according to claim 1 wherein the segregation rate of said at least one material having a cholesteric order is greater than the polymerization rate of said least one liquid crystal material.
Claim 15
Dependent Claim
22 words
A broadband polarizer according to claim 1 wherein said at least one material having a cholesteric order is a cholesteric liquid crystal.
Claim 16
Dependent Claim
23 words
A broadband polarizer according to claim 1 wherein said at least one material having a cholesteric order is a cyclic liquid crystal siloxane.
Claim 17
Dependent Claim
26 words
A broadband polarizer according to claim 1 wherein said at least one material having a cholesteric order is a material which is polymerized by cationic polymerization.
Claim 18
Dependent Claim
24 words
A broadband polarizer according to claim 1 wherein said at least one liquid crystal material is a material which is polymerized by cationic polymerization.
Claim 19
Dependent Claim
25 words
A broadband polarizer according to claim 1 wherein said at least one liquid crystal material is a low molecular weight material having a cholesteric order.
Claim 20
Dependent Claim
28 words
A broadband polarizer according to claim 1 wherein said film has a thickness sufficient to reflect 100 percent of incident circularly polarized electromagnetic radiation over said given bandwidth.
Claim 21
Dependent Claim
22 words
A broadband polarizer according to claim 1 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the visible spectrum.
Claim 22
Dependent Claim
26 words
A broadband polarizer according to claim 1 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the infrared portion of the electromagnetic spectrum.
Claim 23
Dependent Claim
26 words
A broadband polarizer according to claim 1 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the ultraviolet portion of the electromagnetic spectrum.
Claim 24
Dependent Claim
35 words
A broadband polarizer according to claim 1 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is in an anisotropic liquid state.
Claim 25
Dependent Claim
34 words
A broadband polarizer according to claim 1 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is in the solid state.
Claim 26
Dependent Claim
18 words
A broadband polarizer according to claim 1 wherein at least one material having a cholesteric order is unpolymerized.
Claim 27
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said at least one liquid crystal material is unpolymerized.
Claim 28
Dependent Claim
31 words
A broadband polarizer according to claim 1 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is unpolymerized.
Claim 29
Dependent Claim
17 words
A broadband polarizer according to claim 1 wherein said given bandwidth is in excess of 400 nm.
Claim 30
Dependent Claim
22 words
A broadband polarizer according to claim 1 wherein said given bandwidth is in a range of over 400 nm to 2000 nm.
Claim 31
Independent Claim
103 words
A method of fabricating a broadband polarizer comprising the step of: converting a mixture of at least one material having a cholesteric order and sites of a given helix pitch and at least one liquid crystal material such that said at least one liquid crystal material having a cholesteric order is converted to a film wherein said sites of given helix pitch are changed to sites of nonlinearly varying helix pitch across the thickness of said film and wherein said at least one liquid crystal material is distributed across the thickness of said film and disposed at said sites of nonlinearly varying pitch.
Claim 32
Independent Claim
103 words
A method of fabricating a broadband polarizer comprising the step of: converting a mixture of at least one material having a cholesteric order and sites of a given helix pitch and at least one liquid crystal material such that said at least one liquid crystal material having a cholesteric order is converted to a film wherein said sites of given helix pitch are changed to sites of nonlinearly varying helix pitch across the thickness of said film and wherein said at least one liquid crystal material is distributed across the thickness of said film and disposed at said sites of nonlinearly varying pitch.
Claim 33
Dependent Claim
19 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a polymer.
Claim 34
Dependent Claim
19 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a monomer.
Claim 35
Dependent Claim
19 words
A method according to claim 30 wherein said at least one material having a cholesteric order is an oligomer.
Claim 36
Dependent Claim
22 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a low molecular weight material.
Claim 37
Dependent Claim
19 words
A method, according to claim 30 wherein said at least one liquid crystal material is a nematic liquid crystal.
Claim 38
Dependent Claim
19 words
A method according to claim 30 wherein said at least one liquid crystal material is a smectic liquid crystal.
Claim 39
Dependent Claim
18 words
A method according to claim 30 wherein said at least one material having a cholesteric order is photopolymerizable.
Claim 40
Dependent Claim
16 words
A method according to claim 30 wherein said at least one liquid crystal material is photopolymerizable.
Claim 41
Dependent Claim
30 words
A method according to claim 30 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is polymerizable.
Claim 42
Dependent Claim
31 words
A method according to claim 30 wherein the segregation rate of said at least one liquid crystal material is greater than the polymerization rate of whichever of said materials is polymerized.
Claim 43
Dependent Claim
34 words
A method according to claim 30 wherein the segregation rate of said at least one liquid crystal material is greater than the polymerization rate of said at least one material having a cholesteric order.
Claim 44
Dependent Claim
24 words
A method according to claim 30 wherein the segregation rate of said at least one liquid crystal material is greater than its polymerization rate.
Claim 45
Dependent Claim
21 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a cholesteric liquid crystal.
Claim 46
Dependent Claim
21 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a cyclic liquid crystal.
Claim 47
Dependent Claim
25 words
A method according to claim 30 wherein said at least one material having a cholesteric order is a material which is polymerized by cationic polymerization.
Claim 48
Dependent Claim
23 words
A method according to claim 30 wherein said at least one liquid crystal material is a material which is polymerized by cationic polymerization.
Claim 49
Dependent Claim
24 words
A method according to claim 30 wherein said at least one liquid crystal material having a cholesteric order is a low molecular weight material.
Claim 50
Dependent Claim
27 words
A method according to claim 30 wherein said film has a thickness sufficient to reflect 100 percent of incident circularly polarized electromagnetic radiation over said given bandwidth.
Claim 51
Dependent Claim
21 words
A method according to claim 30 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the visible spectrum.
Claim 52
Dependent Claim
25 words
A method according to claim 30 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the infrared portion of the electromagnetic spectrum.
Claim 53
Dependent Claim
25 words
A method according to claim 30 wherein said film is reflective of incident circularly polarized electromagnetic radiation in the ultraviolet portion of the electromagnetic spectrum.
Claim 54
Dependent Claim
34 words
A method according to claim 30 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is in an anisotropic liquid state.
Claim 55
Dependent Claim
33 words
A method according to claim 30 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is in the solid state.
Claim 56
Dependent Claim
18 words
A method according to claim 30 wherein said at least one material having a cholesteric order is unpolymerized.
Claim 57
Dependent Claim
16 words
A method according to claim 30 wherein said at least one liquid crystal material is unpolymerizable.
Claim 58
Dependent Claim
30 words
A method according to claim 30 wherein at least one of said at least one material having a cholesteric order and said at least one liquid crystal material is unpolymerizable.
Claim 59
Dependent Claim
43 words
A method according to claim 30 wherein the step of converting includes the step of: mixing said at least one material having a cholesteric order and said at least one liquid crystal material in a given ratio by weight to form a mixture.
Claim 60
Dependent Claim
14 words
A method according to claim 57 wherein said given ratio by weight is 2:1.
Claim 61
Dependent Claim
38 words
A method according to claim 57 wherein said given ratio by weight of said at least one material having a cholesteric order and said at least one liquid crystal material is in a range of 1:1 to 6:1.
Claim 62
Dependent Claim
17 words
A method according to claim 57 further including the step of adding a photoinitiator into said mixture.
Claim 63
Dependent Claim
18 words
A method according to claim 60 further including the step of adding a chiral additive to said mixture.
Claim 64
Dependent Claim
26 words
A method according to claim 61 further including the step of heating said mixture at a temperature sufficient to maintain said mixture in a liquid state.
Claim 65
Dependent Claim
40 words
A method according to claim 62 further including the step of irradiating said mixture with electromagnetic radiation to polymerize at least one of said at least one material having a cholesteric order and said at least one liquid crystal material.
Claim 66
Dependent Claim
23 words
A method according to claim 63 wherein the step of irradiating said mixture includes the step of applying actinic radiation to said mixture.
Claim 67
Dependent Claim
55 words
A single layer polarizer comprising: a film of a first liquid crystal material and a second liquid crystal material, one of said materials having sites of nonlinearly varying helix pitch distributed across the thickness of said film the other of said materials being distributed across the thickness of said film and disposed at said sites.
Claim 68
Dependent Claim
55 words
A single layer polarizer comprising: a film of a first liquid crystal material and a second liquid crystal material, one of said materials having sites of nonlinearly varying helix pitch distributed across the thickness of said film the other of said materials being distributed across the thickness of said film and disposed at said sites.
Claim 69
Independent Claim
63 words
A method of forming a single layer polarizer comprising the steps of: forming a film from a first liquid crystal material and a second liquid crystal material, one of said materials having sites of nonlinearly varying helix pitch distributed across the thickness of said film the other of said materials being distributed across the thickness of said film and disposed at said sites.
Claim 70
Independent Claim
63 words
A method of forming a single layer polarizer comprising the steps of: forming a film from a first liquid crystal material and a second liquid crystal material, one of said materials having sites of nonlinearly varying helix pitch distributed across the thickness of said film the other of said materials being distributed across the thickness of said film and disposed at said sites.
Claim 71
Dependent Claim
63 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of nonlinearly varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites at least one of said materials being unpolymerized, said film having a given bandwidth.
Claim 72
Dependent Claim
63 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of nonlinearly varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites at least one of said materials being unpolymerized, said film having a given bandwidth.
Claim 73
Dependent Claim
62 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites at least one of said materials being unpolymerized, said film having a given bandwidth.
Claim 74
Dependent Claim
62 words
A broadband polarizer comprising a film of at least one material having a cholesteric order which includes sites of varying helix pitch distributed across the thickness of said film and at least one liquid crystal material distributed across the thickness of said film and disposed at said sites at least one of said materials being unpolymerized, said film having a given bandwidth.
References Cited (Backward Citations)
US3650603A
Cited
US4388453A
Cited
US4637896A
Cited
US4944578A
Cited
EP0506176A1
Cited
US5412492A
Cited
US5427828A
Cited
EP0606940A2
Cited
US5506704A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-24 | 2001-05-26 | 2001-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-24 | 2005-05-26 | 2005-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-24 | 2009-05-26 | 2009-11-25 | $7700.00 | Window Closed / Lapsed |