US4688900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light modulating material comprising a liquid crystal dispersion in a plastic matrix
Assignee: Kent State University
•
Filing: 1985-09-17
•
Granted: 1987-08-25
•
Expires: 2005-09-17
Abstract
Abstract A light modulating material consisting of droplets of liquid crystal in a clear or light transmitting, flexible plastic sheet or film, such as a cured epoxy. The light modulating material is prepared by dissolving liquid crystal in an uncured resin and then curing the resin so that droplets of liquid crystal spontaneously form and are uniformly dispersed throughout the sheet or film. The new material shows a reversible, high contrast optical response from an opaque scattering mode to a clear light transmission mode when either the temperature of the material is changed to transform the liquid crystal into the isotropic phase or an electric field is applied across the material. The material is optically responsive to strain, whereby under tension it acts to polarize incident light. Curing the material in the presence of an applied field also causes it to act as an electrically addressable polarizer.
Inventors
- 👤 Joseph W. Doane
- 👤 Giuseppe Chidichimo
- 👤 Nuno A. P. Vaz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:40
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/54; C09K19/542; C09K19/544; G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
40 words
A light modulating material comprising droplets of liquid crystal dispersed in a solid, light transmissive resin matrix, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof.
Claim 2
Dependent Claim
40 words
A light modulating material comprising droplets of liquid crystal dispersed in a solid, light transmissive resin matrix, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof.
Claim 3
Dependent Claim
15 words
A light modulating material as claimed in claim 1 wherein said resin is an epoxy.
Claim 4
Dependent Claim
16 words
A light modulating material as claimed in claim 1 wherein said liquid crystal comprises a cyanobiphenyl.
Claim 5
Dependent Claim
15 words
A light modulating material as claimed in claim 1 wherein said resin is a polyurethane.
Claim 6
Dependent Claim
66 words
A light modulating material as claimed in claim 1 wherein said liquid crystal has an optical index of refraction in the isotropic phase which is similar to that of said resin, whereby said material transmits light, and an optical index of refraction in the liquid crystalline phase which differs from that of said resin matrix such that incident light is scattered and said material is opaque.
Claim 7
Dependent Claim
16 words
A light modulating material as claimed in claim 5 wherein said liquid crystal is a cyanobiphenyl.
Claim 8
Dependent Claim
32 words
A light modulating material as claimed in claim 1 wherein said liquid crystal is nematic having an ordinary optical index of refraction similar to the index of refraction of said resin matrix.
Claim 9
Dependent Claim
16 words
A light modulating material as claimed in claim 7 wherein said liquid crystal is a cyanobiphenyl.
Claim 10
Dependent Claim
33 words
A material capable of modulating light comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in uncured epoxy resin and said droplets being spontaneously formed during curing.
Claim 11
Dependent Claim
33 words
A material capable of modulating light comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in uncured epoxy resin and said droplets being spontaneously formed during curing.
Claim 12
Dependent Claim
14 words
A material as claimed in claim 9 wherein said liquid crystal comprises a cyanobiphenyl.
Claim 13
Dependent Claim
88 words
A thermally responsive, light modulating material capable of reversibly changing between opaque and light transmissive states comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in the uncured epoxy resin and said droplets being spontaneously formed during curing, said liquid crystal having in its isotropic phase an optical index of refraction such as to permit transmission of incident light, and having in its liquid crystalline phase an optical index of refraction such that incident light is scattered and said material is opaque.
Claim 14
Dependent Claim
88 words
A thermally responsive, light modulating material capable of reversibly changing between opaque and light transmissive states comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in the uncured epoxy resin and said droplets being spontaneously formed during curing, said liquid crystal having in its isotropic phase an optical index of refraction such as to permit transmission of incident light, and having in its liquid crystalline phase an optical index of refraction such that incident light is scattered and said material is opaque.
Claim 15
Dependent Claim
14 words
A material as claimed in claim 11 wherein said liquid crystal comprises a cyanobiphenyl.
Claim 16
Dependent Claim
140 words
An electrically responsive device capable of being reversibly switched between opaque and light transmissive states comprising electrode means, a synthetic resin matrix between said electrode means, droplets of nematic liquid crystal dispersed in said resin matrix, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said resin matrix and liquid crystal droplets, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of the matrix so that incident light is passed through said device in the presence of an electric field, and having its other index refraction such that incident light is scattered and said device is opaque in the absence of an electric field.
Claim 17
Dependent Claim
140 words
An electrically responsive device capable of being reversibly switched between opaque and light transmissive states comprising electrode means, a synthetic resin matrix between said electrode means, droplets of nematic liquid crystal dispersed in said resin matrix, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said resin matrix and liquid crystal droplets, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of the matrix so that incident light is passed through said device in the presence of an electric field, and having its other index refraction such that incident light is scattered and said device is opaque in the absence of an electric field.
Claim 18
Dependent Claim
16 words
A device as claimed in claim 13, including a pleochroic dye incorporated in said liquid crystal.
Claim 19
Dependent Claim
14 words
A device as claimed in claim 13 wherein said liquid crystal comprises a cyanobiphenyl.
Claim 20
Dependent Claim
83 words
A light polarizing material comprising droplets of liquid crystal dispersed in a matrix of solid, light-transmissive resin, said liquid crystal being soluble in the matrix-forming composition, said droplets being spontaneously formed from solution in the composition during solidification thereof, and said liquid crystal having an ordinary index of refraction in its liquid crystalline phase such that, when said polarizing material is strained in one direction, one component of plane polarized incident light will be scattered and the other component will be transmitted therethrough.
Claim 21
Dependent Claim
83 words
A light polarizing material comprising droplets of liquid crystal dispersed in a matrix of solid, light-transmissive resin, said liquid crystal being soluble in the matrix-forming composition, said droplets being spontaneously formed from solution in the composition during solidification thereof, and said liquid crystal having an ordinary index of refraction in its liquid crystalline phase such that, when said polarizing material is strained in one direction, one component of plane polarized incident light will be scattered and the other component will be transmitted therethrough.
Claim 22
Dependent Claim
14 words
A material as claimed in claim 16 wherein said liquid crystalline phase is nematic.
Claim 23
Dependent Claim
16 words
A light modulating material as claimed in claim 16 wherein said liquid crystal comprises a cyano-biphenyl.
Claim 24
Dependent Claim
129 words
An electrically responsive, light modulating device comprising spaced, transparent electrode means, a sheet or film formed by a light transmissive synthetic resin matrix containing droplets of liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said sheet or film, said sheet or film being stretched so that light is transmitted through said device and is polarized when said electric field is off, and said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said sheet or film, whereby unpolarized light is transmitted through said device when the electric field is on.
Claim 25
Dependent Claim
129 words
An electrically responsive, light modulating device comprising spaced, transparent electrode means, a sheet or film formed by a light transmissive synthetic resin matrix containing droplets of liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said sheet or film, said sheet or film being stretched so that light is transmitted through said device and is polarized when said electric field is off, and said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said sheet or film, whereby unpolarized light is transmitted through said device when the electric field is on.
Claim 26
Dependent Claim
14 words
A device as claimed in claim 19 wherein said liquid crystal is a cyanobiphenyl.
Claim 27
Dependent Claim
14 words
A device as claimed in claim 20 wherein said matrix is an epoxy resin.
Claim 28
Dependent Claim
83 words
A resin matrix containing droplets of nematic liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidfication thereof, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said matrix so that at least one component of incident light is transmitted when the liquid crystal directors are aligned and so that incident light is scattered when the liquid crystal directors are misaligned.
Claim 29
Dependent Claim
83 words
A resin matrix containing droplets of nematic liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidfication thereof, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said matrix so that at least one component of incident light is transmitted when the liquid crystal directors are aligned and so that incident light is scattered when the liquid crystal directors are misaligned.
Claim 30
Dependent Claim
102 words
An electrically addressable light modulating device capable of being reversibly switched between a polarizing mode and a non-polarizing light transmitting mode comprising: a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets having their optical axes aligned in one direction in the plane of said matrix in said polarizing mode and normal to the plane of said matrix in said non-polarizing, light transmitting mode, and means to deliver a field effective to switch said device from one of said modes to the other.
Claim 31
Dependent Claim
102 words
An electrically addressable light modulating device capable of being reversibly switched between a polarizing mode and a non-polarizing light transmitting mode comprising: a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets having their optical axes aligned in one direction in the plane of said matrix in said polarizing mode and normal to the plane of said matrix in said non-polarizing, light transmitting mode, and means to deliver a field effective to switch said device from one of said modes to the other.
Claim 32
Dependent Claim
45 words
A device as claimed in claim 23 wherein said optical axes are normal to the plane of said matrix and said device is in its non-polarizing, light transmitting mode when the field is on, and is in its other mode when the field is off.
Claim 33
Dependent Claim
46 words
A device as claimed in claim 23 wherein said optical axes are aligned in one direction in the plane of said matrix and said device is in its polarizing mode when the field is on, and is in its other mode when the field is off.
Claim 34
Dependent Claim
17 words
The device as claimed in claim 23, 24 or 25 wherein said liquid crystal is a cyanobyphenyl.
Claim 35
Dependent Claim
86 words
A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged so that their optical axes will scatter at least one component of light incident on a surface of said sheet and being responsive to a field whereby said optical axes are aligned normal to said surfare so that incident light is transmitted through said sheet.
Claim 36
Dependent Claim
86 words
A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged so that their optical axes will scatter at least one component of light incident on a surface of said sheet and being responsive to a field whereby said optical axes are aligned normal to said surfare so that incident light is transmitted through said sheet.
Claim 37
Dependent Claim
34 words
A light modulating material as claimed in claim 27 wherein said microdroplets are arranged so that said optical axes are aligned in one direction parallel to said surface in the absence of said field.
Claim 38
Dependent Claim
28 words
A light modulating material as claimed in claim 27 characterized in that in the absence of said field said optical axes are unaligned and said material is opaque.
Claim 39
Dependent Claim
19 words
A light modulating material as claimed in claim 27, 28, or 29 wherein said liquid crystal is a cyanobiphenyl.
Claim 40
Dependent Claim
95 words
A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged with their optical axes normal to a surface of said sheet so that incident light on said surface is transmitted through said material and being responsive to a field or to strain whereby said optical axes are caused to shift to an orientation effective to scatter at least one component of said incident light.
Claim 41
Dependent Claim
95 words
A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged with their optical axes normal to a surface of said sheet so that incident light on said surface is transmitted through said material and being responsive to a field or to strain whereby said optical axes are caused to shift to an orientation effective to scatter at least one component of said incident light.
Claim 42
Dependent Claim
61 words
A field responsive, light modulating device comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented with their optical axes aligned in one direction, and means for establishing a field effective to shift the alignment of said optical axes.
Claim 43
Dependent Claim
61 words
A field responsive, light modulating device comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented with their optical axes aligned in one direction, and means for establishing a field effective to shift the alignment of said optical axes.
Claim 44
Dependent Claim
63 words
A field responsive, light modulating material comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented so that their optical axes are aligned in one direction and being responsive to a field whereby the alignment of said optical axes is changed.
Claim 45
Dependent Claim
63 words
A field responsive, light modulating material comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented so that their optical axes are aligned in one direction and being responsive to a field whereby the alignment of said optical axes is changed.
Claim 46
Independent Claim
36 words
A method of making a light modulating material comprising the steps of dissolving liquid crystal in a solidifiable, light transmissive resin matrix-forming composition, and thereafter solidifying said composition and causing spontaneous formation of liquid crystal droplets.
Claim 47
Independent Claim
36 words
A method of making a light modulating material comprising the steps of dissolving liquid crystal in a solidifiable, light transmissive resin matrix-forming composition, and thereafter solidifying said composition and causing spontaneous formation of liquid crystal droplets.
Claim 48
Dependent Claim
14 words
A method as claimed in claim 34 wherein said matrix comprises clear epoxy resin.
Claim 49
Dependent Claim
17 words
A method as claimed in claim 34 wherein said matrix is solidified by exposure to ultra-violet light.
Claim 50
Dependent Claim
25 words
A method as claimed in claim 34 including the step of stretching the solidified matrix to orient the optical axes of said liquid crystal droplets.
Claim 51
Dependent Claim
14 words
A method as claimed in claim 34 wherein said liquid crystal comprises a cyanobiphenyl.
Claim 52
Independent Claim
59 words
A method of making a material capable of exhibiting contrasting response from opaque to light transmissive conditions comprising the steps of stirring together liquid crystal, epoxy resin, and curing agent to form a mixture in which the liquid crystal is dissolved, and curing said mixture to form a solid which contains droplets of liquid crystal spontaneously formed upon curing.
Claim 53
Independent Claim
59 words
A method of making a material capable of exhibiting contrasting response from opaque to light transmissive conditions comprising the steps of stirring together liquid crystal, epoxy resin, and curing agent to form a mixture in which the liquid crystal is dissolved, and curing said mixture to form a solid which contains droplets of liquid crystal spontaneously formed upon curing.
Claim 54
Independent Claim
113 words
A method of making a light modulating material comprising the steps of dissolving liquid crystal in a resin capable of being cured to form a clear matrix, said liquid crystal having the characteristic of spontaneously forming droplets upon curing of said resin, and thereafter curing said resin to form a matrix containing a uniform dispersion of liquid crystal droplets, said liquid crystal being further characterized by an ordinary optical index of refraction similar to that of the cured resin so that at least one component of incident light will be transmitted when the liquid crystal directors are aligned and so that incident light will be scattered when the liquid crystal directors are misaligned.
Claim 55
Independent Claim
113 words
A method of making a light modulating material comprising the steps of dissolving liquid crystal in a resin capable of being cured to form a clear matrix, said liquid crystal having the characteristic of spontaneously forming droplets upon curing of said resin, and thereafter curing said resin to form a matrix containing a uniform dispersion of liquid crystal droplets, said liquid crystal being further characterized by an ordinary optical index of refraction similar to that of the cured resin so that at least one component of incident light will be transmitted when the liquid crystal directors are aligned and so that incident light will be scattered when the liquid crystal directors are misaligned.
Claim 56
Dependent Claim
15 words
A method as claimed in claim 40 wherein said liquid crystal droplets comprise a cyanobiphenyl.
Claim 57
Dependent Claim
22 words
A method as claimed in claim 40 including the step of straining the matrix to orient the optical axes of said droplets.
Claim 58
Independent Claim
66 words
A method of making a liquid crystal microdroplet containing, light modulating material comprising the steps of: dissolving liquid crystal in a light transmissive synthetic resin matrix-forming composition, establishing a field effective to align the optical axes of the microdroplets, and solidfying said composition in the presence of said field whereby the dispersed microdroplets that form spontaneously during solidification have their optical axes aligned by said field.
Claim 59
Independent Claim
66 words
A method of making a liquid crystal microdroplet containing, light modulating material comprising the steps of: dissolving liquid crystal in a light transmissive synthetic resin matrix-forming composition, establishing a field effective to align the optical axes of the microdroplets, and solidfying said composition in the presence of said field whereby the dispersed microdroplets that form spontaneously during solidification have their optical axes aligned by said field.
Claim 60
Dependent Claim
12 words
The method of claim 43 wherein said liquid crystal is a cyanobiphenyl.
Claim 61
Dependent Claim
27 words
The method of claim 43 or claim 44 wherein said liquid crystal has an ordinary index of refraction similar to the refractive index of the solidified matrix.
Claim 62
Dependent Claim
24 words
The subject matter of claims 1, 9, 11, 16, 19, 34, 39, 40, or 43 wherein said liquid crystal comprises a nematic liquid crystal.
Claim 63
Dependent Claim
30 words
The subject matter of claim 1, 9, 11, 13, 16, 19, 22, 23, 27, 31, 32, 33, 34, 39, 40 or 43 wherein said liquid crystal exhibits positive dielectric anisotropy.
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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) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |