US3848965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling monochromatic collimated light by controlling the light reflection band of a liquid crystal
Assignee: Xerox Corp
•
Filing: 1973-10-17
•
Granted: 1974-11-19
•
Expires: 1993-10-17
Abstract
Abstract A method wherein an optically negative liquid crystal film or layer which initially does not substantially scatter incident monochromatic light is caused to diffusely scatter the incident light by means of relatively small pitch changes effected in the optically negative material. An imaging system wherein an optically negative liquid crystal film is imaged in the desired image configuration by the above-described method is also disclosed.
Inventors
- 👤 J Adams
- 👤 W Haas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:31
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13718
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
136 words
A method for placing a layer of an optically negative liquid crystal material in a diffusely light scattering condition comprising a. providing a layer of an optically negative liquid crystalline material in its Grandjean texture state, said optically negative material having a light reflection band with center wavelength lambda o. b. directing incident collimated monochromatic light upon said liquid crystal layer at an angle of incidence from 0* to about 15*, wherein said incident light is not diffusely scattered by said liquid crystal layer; and c. applying to said liquid crystal film some external stimulus which is capable of changing the location of the light reflection band and applying said stimulus until the incident light is diffusely scattered by said liquid crystal layer whereby the diffusely scattered light is observable from a wide range of angles.
Claim 2
Independent Claim
136 words
A method for placing a layer of an optically negative liquid crystal material in a diffusely light scattering condition comprising a. providing a layer of an optically negative liquid crystalline material in its Grandjean texture state, said optically negative material having a light reflection band with center wavelength lambda o. b. directing incident collimated monochromatic light upon said liquid crystal layer at an angle of incidence from 0* to about 15*, wherein said incident light is not diffusely scattered by said liquid crystal layer; and c. applying to said liquid crystal film some external stimulus which is capable of changing the location of the light reflection band and applying said stimulus until the incident light is diffusely scattered by said liquid crystal layer whereby the diffusely scattered light is observable from a wide range of angles.
Claim 3
Dependent Claim
35 words
The method as defined in claim 1 wherein said liquid crystalline layer is arranged between a pair of electrodes at least one of which is substaNtially transparent and said external stimulus comprises an electric field.
Claim 4
Dependent Claim
19 words
The method as defined in claim 2 wherein said liquid crystal layer is shaped in a desired image configuration.
Claim 5
Dependent Claim
21 words
The method as defined in claim 2 wherein said electric field is applied to said liquid crystal layer in imagewise configuration.
Claim 6
Dependent Claim
15 words
The method as defined in claim 4 wherein said electrodes comprise an X-Y address system.
Claim 7
Dependent Claim
21 words
The method as defined in claim 4 wherein at least one of said electrodes is shaped in a desired image configuration.
Claim 8
Dependent Claim
29 words
The method as defined in claim 4 wherein one of said electrodes includes a photoconductive insulating surface and imagewise activating electromagnetic radiation is directed upon said photoconductive insulating surface.
Claim 9
Dependent Claim
23 words
The method as defined in claim 2 wherein the liquid crystal layer has a thickness of from about 0.5 to about 50 microns.
Claim 10
Dependent Claim
16 words
The method as defined in claim 2 wherein said incident light is substantially completely circularly polarized.
Claim 11
Dependent Claim
16 words
The method as defined in claim 2 wherein said incident light is provided by a laser.
Claim 12
Dependent Claim
17 words
The method as defined in claim 2 and further including the step of removing said electric field.
Claim 13
Dependent Claim
26 words
The method as defined in claim 2 wherein said optically negative liquid crystal film has a lambda o in the visible region of the electromagnetic spectrum.
Claim 14
Dependent Claim
20 words
The method as defined in claim 2 wherein said optically negative liquid crystalline material comprises a cholesteric liquid crystalline material.
Claim 15
Dependent Claim
24 words
The method as defined in claim 2 wherein said optically negative liquid crystalline material comprises a mixture of cholesteric and nematic liquid crystalline materials.
Claim 16
Dependent Claim
27 words
The method as defined in claim 2 wherein said optically negative liquid crystalline material comprises a mixture of nematic liquid crystalline material and optically active non-mesomorphic material.
Claim 17
Dependent Claim
24 words
The method as defined in claim 2 wherein the liquid crystal layer has a thickness of from about 0.5 microns to about 20 microns.
Claim 18
Dependent Claim
24 words
The method as defined in claim 12 wherein the liquid crystal layer has a thickness of from about 3 microns to about 10 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |