Patent EP0409442A2 successfully refreshed from Google Patents.
EP0409442A2
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EP
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Encapsulated liquid crystal apparatus having low off-axis haze and operable by a sine-wave power source
Assignee: Raychem Corp
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Filing: 1990-07-03
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Granted: —
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Expires: 2010-07-03
Abstract
Abstract A liquid crystal apparatus including a low birefringence encapsulated liquid crystal material in a containment medium. The difference between the ordinary index of refraction and extraordinary index of refraction of the liquid crystal material is between about .050 and .115. The index of refraction of the containment is greater than the ordinary index of refraction of the liquid crystal material. The liquid crystal apparatus provides low haze at off-axis viewing angles and permits efficient sine-wave power operation.
Inventors
- 👤 Paul Drzaic
- 👤 Peter H. Van Konynenburg
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 22:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; C; C09; C09K; C09K19/00; C09K19/52; C09K19/54; C09K19/542; C09K19/544
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
72 words
A liquid crystal apparatus comprising: a containment medium and a low birefringence liquid crystal material dispersed in plural volumes in said containment medium, the effective index of refraction of said liquid crystal material being substantially unchanged for viewing angles up to about plus or minus 30° from the normal, and wherein the index of refraction of the containment medium is greater than the ordinary index of refraction of the liquid crystal material.
Claim 2
Dependent Claim
72 words
A liquid crystal apparatus comprising: a containment medium and a low birefringence liquid crystal material dispersed in plural volumes in said containment medium, the effective index of refraction of said liquid crystal material being substantially unchanged for viewing angles up to about plus or minus 30° from the normal, and wherein the index of refraction of the containment medium is greater than the ordinary index of refraction of the liquid crystal material.
Claim 3
Dependent Claim
20 words
The liquid crystal apparatus of Claim 1 disposed between two optically transparent panels to control the transmission of light therethrough.
Claim 4
Dependent Claim
26 words
The liquid crystal apparatus of Claim 2 further including a sine-wave power source for applying an electric field across said liquid crystal material to transmit light.
Claim 5
Dependent Claim
27 words
The liquid crystal apparatus of Claim 1 wherein the birefringence of said liquid crystal material is not greater than about 0.115 and not less than about 0.050.
Claim 6
Dependent Claim
26 words
The liquid crystal apparatus of Claim 1 wherein acceptable haze levels exist at viewing angles of up to about plus or minus 60° from the normal.
Claim 7
Dependent Claim
68 words
A liquid crystal apparatus comprising: an encapsulated liquid crystal material in a containment medium, said liquid crystal material having an extraordinary index of refraction and an ordinary index of refraction wherein the difference between said extraordinary index of refraction and ordinary index of refraction is between about .050 and .115, and wherein the index of refraction of the containment medium is greater than said ordinary index of refraction.
Claim 8
Dependent Claim
68 words
A liquid crystal apparatus comprising: an encapsulated liquid crystal material in a containment medium, said liquid crystal material having an extraordinary index of refraction and an ordinary index of refraction wherein the difference between said extraordinary index of refraction and ordinary index of refraction is between about .050 and .115, and wherein the index of refraction of the containment medium is greater than said ordinary index of refraction.
Claim 9
Dependent Claim
29 words
The liquid crystal apparatus of Claim 6 wherein the difference between the said extraordinary index of refraction and said ordinary index of refraction is between about 0.080 and 0.100.
Claim 10
Dependent Claim
30 words
The liquid crystal apparatus of Claim 6 wherein the index of refraction of the containment medium is not greater than about 0.020 than that of said ordinary index of refraction.
Claim 11
Dependent Claim
30 words
The liquid crystal apparatus of Claim 8 wherein the index of refraction of the containment medium is no greater than about 0.010 than that of said ordinary index of refraction.
Claim 12
Dependent Claim
35 words
The liquid crystal apparatus of Claim 6 wherein said liquid crystal material is disposed in a plurality of capsule-like volumes, and the mean volume diameter of said capsules is between about 2 and 8 microns.
Claim 13
Dependent Claim
18 words
The liquid crystal apparatus of Claim 10 wherein said mean volume diameter is about 3 to 4 microns.
Claim 14
Dependent Claim
40 words
The liquid crystal apparatus of Claim 6 further including two optically transparent panels between which the liquid crystal apparatus is disposed to form a window means wherein the liquid crystal apparatus controls the transmission of light through said window means.
Claim 15
Dependent Claim
25 words
The liquid crystal apparatus of Claim 6 further including electrode means for applying an electric field across at least some of said liquid crystal material.
Claim 16
Dependent Claim
20 words
The liquid crystal apparatus of Claim 13 further including electrical circuit means for providing electrical power to said electrode means.
Claim 17
Dependent Claim
26 words
The liquid crystal apparatus of Claim 14 wherein said electrical circuit means includes a sine-wave power source for applying said electric field without producing objectionable haze.
Claim 18
Dependent Claim
107 words
A window comprising two optically transparent panels between which is disposed an encapsulated liquid crystal material in a containment medium, said liquid crystal material having an extraordinary index of refraction and an ordinary index of refraction wherein the difference between said extraordinary index of refraction and said ordinary index of refraction is between about .050 and .115, and wherein the index of refraction of the containment medium is greater than said ordinary index of refraction, and wherein said liquid crystal material may be switched between a field-on and field-off state by the application of an electric field from a sine-wave power source without producing objectionable haze levels.
Claim 19
Dependent Claim
107 words
A window comprising two optically transparent panels between which is disposed an encapsulated liquid crystal material in a containment medium, said liquid crystal material having an extraordinary index of refraction and an ordinary index of refraction wherein the difference between said extraordinary index of refraction and said ordinary index of refraction is between about .050 and .115, and wherein the index of refraction of the containment medium is greater than said ordinary index of refraction, and wherein said liquid crystal material may be switched between a field-on and field-off state by the application of an electric field from a sine-wave power source without producing objectionable haze levels.
Claim 20
Independent Claim
72 words
A method of making a light control device having low off-axis haze comprising: selecting a birefringent liquid crystal material having a birefringence of between about 0.050 and 0.115, and mixing said liquid crystal material and a containment medium to form plural copsule-like volumes containing said liquid crystal material and such that the index of refraction of said containment medium is greater than the ordinary index of refraction of said liquid crystal material.
Claim 21
Independent Claim
72 words
A method of making a light control device having low off-axis haze comprising: selecting a birefringent liquid crystal material having a birefringence of between about 0.050 and 0.115, and mixing said liquid crystal material and a containment medium to form plural copsule-like volumes containing said liquid crystal material and such that the index of refraction of said containment medium is greater than the ordinary index of refraction of said liquid crystal material.
Claim 22
Dependent Claim
22 words
The method of Claim 17 further comprising adding a polymer material to said containment medium to adjust the index of refraction thereof.
Claim 23
Dependent Claim
32 words
The method of Claim 17 wherein the effective index of refraction of said liquid crystal material is substantially unchanged for viewing angles up to about plus or minus 30° from the normal.
Claim 24
Dependent Claim
18 words
The method of Claim 17 further including applying the light control device to a generally optically transmissive panel.
Claim 25
Dependent Claim
27 words
The method of Claim 17 further including applying a sine-wave voltage to at least some of said liquid crystal material such that there is no objectionable haze.
Claim 26
Dependent Claim
43 words
The method of Claim 17 further including selecting said containment medium and said liquid crystal material such that the index of refraction of said containment medium is not greater than about 0.020 of said ordinary index of refraction of said liquid crystal material.
Claim 27
Dependent Claim
32 words
The method of Claim 17 wherein said liquid crystal material and said containment medium are mixed to form plural capsule-like volumes having a mean diameter of between about 2 and 8 microns.
Claim 28
Dependent Claim
32 words
The method of Claim 17 wherein the viewing angle of the light control device is about plus or minus 60° from the normal and the haze does not exceed about twenty percent.
References Cited (Backward Citations)
No citation records indexed.
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