Patent US3909114A successfully refreshed from Google Patents.
US3909114A
Expired / Lapsed
US
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Variable spherulitic diffraction
Assignee: Xerox Corp
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Filing: 1974-05-28
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Granted: 1975-09-30
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Expires: 1994-05-28
Abstract
Abstract Variable diffraction of light is provided by utilization of a novel, stable spherulitic texture of a liquid crystalline composition. Light directed upon an array of spherulites in the liquid crystalline composition is diffracted; and the diffraction is changed by applying a voltage across the layer of liquid crystalline composition which results in the change in size of the spherulites. The variable diffraction thus produced can be utilized in optical filters, modulators, color displays and beam splitters.
Inventors
- 👤 Werner E L Haas
- 👤 James E Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
178 words
A method of variably diffracting light, comprising: a. providing on a substrate a layer of aligned liquid crystalline composition comprising a dielectrically negative nematic liquid crystalline material and from about 0.4% to about 3% by weight of an optically acitve material, said liquid crystalline material when not in the aligned state being optically negative and having a light reflection band centered about lambda o 2np where n index of refraction and p helical pitch, the ratio of the helical pitch of the nonaligned liquid crystalline composition to the layer thickness of liquid crystalline composition being from about 1 to about 10, said layer of aligned liquid crystalline composition comprising spherulitic regions of liquid crystalline composition; b. directing light upon said spherulitic regions wherein said light is diffracted; and c. applying a voltage across said layer of liquid crystalline composition in an amount less than that required to produce dynamic scattering in said layer of liquid crystalline composition wherein the spherulitic regions of said liquid crystalline composition are increased in size and diffraction of said light is correspondingly altered.
Claim 2
Independent Claim
178 words
A method of variably diffracting light, comprising: a. providing on a substrate a layer of aligned liquid crystalline composition comprising a dielectrically negative nematic liquid crystalline material and from about 0.4% to about 3% by weight of an optically acitve material, said liquid crystalline material when not in the aligned state being optically negative and having a light reflection band centered about lambda o 2np where n index of refraction and p helical pitch, the ratio of the helical pitch of the nonaligned liquid crystalline composition to the layer thickness of liquid crystalline composition being from about 1 to about 10, said layer of aligned liquid crystalline composition comprising spherulitic regions of liquid crystalline composition; b. directing light upon said spherulitic regions wherein said light is diffracted; and c. applying a voltage across said layer of liquid crystalline composition in an amount less than that required to produce dynamic scattering in said layer of liquid crystalline composition wherein the spherulitic regions of said liquid crystalline composition are increased in size and diffraction of said light is correspondingly altered.
Claim 3
Independent Claim
308 words
A method of variably diffracting light, comprising: a. providing on a substrate, a layer of liquid crystalline composition comprising a dielectrically negative nematic liquid crystalline material and from about 0.4% to about 3% by weight of an optically active material, said liquid crystalline composition when out of contact with an aligning agent or treated substrate being optically negative and having a light reflection band centered about lambda o equal to 2np, where n index of refraction and p helical pitch of said liquid crystalline composition, Said liquid crystalline composition when in contact with an aligning agent or treated substrate being in the homeotropic or homogeneous texture of the nematic mesophase, said liquid crystalline composition when in the homeotropic or homogeneous texture of the nematic mesophase capable of undergoing electrically induced transition into a spherulitic texture upon removal of an applied voltage; the ratio of said helical pitch to the thickness of said layer being from about 1 to about 10; an aligning agent or treated substrate in contact with said layer of liquid crystalline composition; and, within a portion of interest of said layer of liquid crystalline composition, an array of spherulites, said spherulites lacking the optical characteristics of the homeotiopic or homogeneous texture of the nematic mesophase and being surrounded by said liquid crystalline composition having the optical characteristics of the homeotropic or homogeneous texture of the nematic mesophase; b. providing a light source and directing light from said source upon said layer portion of interest having said array of spherulites wherein light from said light source undergoes diffraction; and c. applying a voltage across said layer portion of interest in an amount less than that required to produce dynamic scattering in said layer of liquid crystalline composition wherein the spherulites are increased in size and the diffraction of light from said light source is correspondingly altered.
Claim 4
Independent Claim
308 words
A method of variably diffracting light, comprising: a. providing on a substrate, a layer of liquid crystalline composition comprising a dielectrically negative nematic liquid crystalline material and from about 0.4% to about 3% by weight of an optically active material, said liquid crystalline composition when out of contact with an aligning agent or treated substrate being optically negative and having a light reflection band centered about lambda o equal to 2np, where n index of refraction and p helical pitch of said liquid crystalline composition, Said liquid crystalline composition when in contact with an aligning agent or treated substrate being in the homeotropic or homogeneous texture of the nematic mesophase, said liquid crystalline composition when in the homeotropic or homogeneous texture of the nematic mesophase capable of undergoing electrically induced transition into a spherulitic texture upon removal of an applied voltage; the ratio of said helical pitch to the thickness of said layer being from about 1 to about 10; an aligning agent or treated substrate in contact with said layer of liquid crystalline composition; and, within a portion of interest of said layer of liquid crystalline composition, an array of spherulites, said spherulites lacking the optical characteristics of the homeotiopic or homogeneous texture of the nematic mesophase and being surrounded by said liquid crystalline composition having the optical characteristics of the homeotropic or homogeneous texture of the nematic mesophase; b. providing a light source and directing light from said source upon said layer portion of interest having said array of spherulites wherein light from said light source undergoes diffraction; and c. applying a voltage across said layer portion of interest in an amount less than that required to produce dynamic scattering in said layer of liquid crystalline composition wherein the spherulites are increased in size and the diffraction of light from said light source is correspondingly altered.
Claim 5
Dependent Claim
28 words
The method according to claim 2 wherein in step (b) the light from said light source is transmitted through said layer of liquid crystalline composition and said substrate.
Claim 6
Dependent Claim
28 words
The method of claim 2 wherein said substrate is a reflective substrate and wherein in step (b) the light from said light source is reflected from said substrate.
Claim 7
Dependent Claim
22 words
The method of claim 2 further including a linear polarizer positioned between said light source and said layer of liquid crystalline composition.
Claim 8
Dependent Claim
13 words
The method of claim 2 wherein said applied voltage is a D.C. voltage.
Claim 9
Dependent Claim
33 words
The method of claim 6 wherein said voltage is applied in an amount up to about one-half the amount of voltage required to produce dynamic scattering in said layer of liquid crystalline composition.
Claim 10
Dependent Claim
21 words
The method of claim 2 wherein said voltage is an A.C. voltage at a frequency of up to about 1000 Hz.
Claim 11
Dependent Claim
34 words
The method of claim 8 wherein said voltage is applied in an amount up to to about one-half the amount of voltage required to produce dynamic scattering in said layer of liquid crystalline composition.
Claim 12
Dependent Claim
15 words
The method of claim 2 wherein, in step (c) the spherulites become hexagonal in shape.
Claim 13
Dependent Claim
21 words
The method of claim 2 further including the transmission of at least one wavelength of diffracted light through an optical stop.
Claim 14
Dependent Claim
18 words
The method of claim 11 wherein only one wavelength of diffracted light is passed through the optical stop.
Claim 15
Dependent Claim
20 words
The method of claim 12 wherein said one wavelength of diffracted light is in the visible region of the spectrum.
Claim 16
Dependent Claim
19 words
The method of claim 11 wherein all but one wavelength of diffracted light is passed through the optical stop.
Claim 17
Dependent Claim
22 words
The method of claim 14 wherein said all but one wavelength of diffracted light is in the visible region of the spectrum.
Claim 18
Dependent Claim
26 words
The method of claim 11 wherein said at least one wavelength of diffracted light transmitted through said optical stop is further transmitted through a collimating lens,
Claim 19
Dependent Claim
26 words
The method of claim 11 wherein said at least one wavelength of diffracted light transmitted through said optical stop is further transmitted through a collecting lens.
Claim 20
Dependent Claim
14 words
The method of claim 2 wherein said light source comprises a white light source.
Claim 21
Dependent Claim
12 words
The method of claim 2 wherein said light source comprises a laser.
Claim 22
Dependent Claim
22 words
The method of claim 2 wherein the light directed upon said layer portion of interest in step (c) is in imagewise configuration.
Claim 23
Dependent Claim
20 words
The method of claim 2 wherein the layer portion of interest having said array of spherUlites is in imagewise configuration.
Claim 24
Dependent Claim
32 words
The method according to claim 2 further including the step (d) of decreasing or increasing the voltage applied in step (c) wherein the size of said spherulites is decreased or increased, respectively.
References Cited (Backward Citations)
US3806230A
Cited
US3813145A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |