US3833287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Guest-host liquid crystal device
Assignee: AT&T Inc
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Filing: 1973-03-08
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Granted: 1974-09-03
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Expires: 1993-03-08
Abstract
Abstract A pleochroic material is dissolved in a helically ordered liquid crystal mixture to form a thin film which selectively absorbs unpolarized incident light. In the absence of an electric field through the film, virtually all of the unpolarized light is absorbed by the film, even without the use of an auxiliary polarizer. When an electric field is applied to the film, the molecules thereof are reoriented to a nonabsorbing state. This electrically controlled absorption phenomenon is the basis for an advantageous display device.
Inventors
- 👤 G Taylor
- 👤 D White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:57
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13731; G02F1/13737
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
A device which is responsive to the absence or presence of an electric field for either absorbing or transmitting, respectively, unpolarized light incident thereon, said device comprising a liquid crystal host material characterized by a helical molecular ordering in the absence of an electric field and a homeotropic molecular ordering in the presence of an electric field, a pleochroic guest material in said host material to form a mixture in which said host and guest materials assume corresponding molecular orderings, said guest material being absorptive of said light when helically ordered and nonabsorptive of said light when homeotropically ordered, wherein said guest-host material comprises a thin film having a thickness in the range 5 to 30 microns, wherein said host material comprises a nematic liquid crystal material mixed with an optically active material, and wherein said guest material comprises a soluble nonionic dye, and further including two conductive electrodes positioned respectively adjacent opposing surfaces of said film.
Claim 2
Independent Claim
157 words
A device which is responsive to the absence or presence of an electric field for either absorbing or transmitting, respectively, unpolarized light incident thereon, said device comprising a liquid crystal host material characterized by a helical molecular ordering in the absence of an electric field and a homeotropic molecular ordering in the presence of an electric field, a pleochroic guest material in said host material to form a mixture in which said host and guest materials assume corresponding molecular orderings, said guest material being absorptive of said light when helically ordered and nonabsorptive of said light when homeotropically ordered, wherein said guest-host material comprises a thin film having a thickness in the range 5 to 30 microns, wherein said host material comprises a nematic liquid crystal material mixed with an optically active material, and wherein said guest material comprises a soluble nonionic dye, and further including two conductive electrodes positioned respectively adjacent opposing surfaces of said film.
Claim 3
Dependent Claim
20 words
A device as in claim 1 further including a source connected to said electrodes for applying a variable voltage therebetween.
Claim 4
Dependent Claim
84 words
In combination in an electro-optic device, a guest-host liquid crystal mixture whose molecular ordering is characterized by a helical configuration in the absence of an electric field established in the mixture and by a homeotropic configuration in the presence of an electric field established therein, an electrode means for establishing a variable electric field through said mixture, wherein said mixture includes a host material comprising an optically active material and a nematic liquid crystal mixture, and a guest material comprising an absorptive pleochroic material.
Claim 5
Dependent Claim
84 words
In combination in an electro-optic device, a guest-host liquid crystal mixture whose molecular ordering is characterized by a helical configuration in the absence of an electric field established in the mixture and by a homeotropic configuration in the presence of an electric field established therein, an electrode means for establishing a variable electric field through said mixture, wherein said mixture includes a host material comprising an optically active material and a nematic liquid crystal mixture, and a guest material comprising an absorptive pleochroic material.
Claim 6
Dependent Claim
59 words
A combination as in claim 3 wherein said guest-host liquid crystal mixturE comprises a thin film having a thickness in the range 5 to 30 microns, wherein said aforementioned means comprises two planar conductive electrodes in respective contact with opposing surfaces of said film, and further including a source connected to said electrodes for applying a variable voltage therebetween.
Claim 7
Independent Claim
119 words
A device which is responsive to the absence of presence of an electric field for either absorbing or transmitting, respectively, unpolarized light incident thereon, said device comprising a liquid crystal host material characterized by a helical molecular ordering in the absence of an electric field and a homeotropic molecular ordering in the presence of an electric field, a pleochroic guest material in said host material to form a mixture in which said host and guest materials assume corresponding molecular orderings, said guest material being absorptive of said light when helically ordered and nonabsorptive of said light when homeotropically ordered, wherein said guest-host material comprises a thin film, and two conductive electrodes positioned respectively adjacent opposing surfaces of said film.
Claim 8
Independent Claim
119 words
A device which is responsive to the absence of presence of an electric field for either absorbing or transmitting, respectively, unpolarized light incident thereon, said device comprising a liquid crystal host material characterized by a helical molecular ordering in the absence of an electric field and a homeotropic molecular ordering in the presence of an electric field, a pleochroic guest material in said host material to form a mixture in which said host and guest materials assume corresponding molecular orderings, said guest material being absorptive of said light when helically ordered and nonabsorptive of said light when homeotropically ordered, wherein said guest-host material comprises a thin film, and two conductive electrodes positioned respectively adjacent opposing surfaces of said film.
References Cited (Backward Citations)
US3652148A
Cited
US3703329A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |