Patent US3679290A successfully refreshed from Google Patents.
US3679290A
Expired / Lapsed
US
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Liquid crystal optical filter system
Assignee: Xerox Corp
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Filing: 1971-01-06
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Granted: 1972-07-25
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Expires: 1991-01-06
Abstract
Abstract An optical filter system capable of transmitting light at substantially all wavelengths of incident radiation while simultaneously reflecting radiation at a single wavelength band or plurality of wavelength bands within the incident radiation is described. The system employs liquid crystal films having optically negative properties but which are opposite in intrinsic screw sense.
Inventors
- 👤 James E Adams
- 👤 Lewis B Leder
- 👤 Werner E L Haas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:23
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3016; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
81 words
An optical filter comprising at least one complementary matched pair of liquid crystal films having optically negative characteristics, the two films in each pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered around lambda o will be essentially completely transmitted by said pair.
Claim 2
Dependent Claim
81 words
An optical filter comprising at least one complementary matched pair of liquid crystal films having optically negative characteristics, the two films in each pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered around lambda o will be essentially completely transmitted by said pair.
Claim 3
Dependent Claim
30 words
The optical filter as claimed in claim 1 wherein lambda o for each said complementary matched pair of liquid crystal films is in the visible region of the light spectrum.
Claim 4
Dependent Claim
33 words
The optical filter as defined in claim 1 wherein each liquid crystal film of each said complementary matched pair of liquid crystal films is from about 0.5 to about 20 microns in thickness.
Claim 5
Dependent Claim
33 words
The optical filter as defined in claim 2 wherein each liquid crystal film of each said complementary matched pair of liquid crystal films is from about 3 to about 10 microns in thickness.
Claim 6
Dependent Claim
79 words
The optical filter as defined in claim 1 wherein each liquid crystal film of Each said complementary matched pair of liquid crystal films comprises a composition chosen from the group consisting of: cholesteric liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and nematic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and smectic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and non-liquid crystalline substances which are compatible with cholesteric liquid crystalline substances; and mixtures thereof.
Claim 7
Independent Claim
159 words
A method for removing at least one wavelength band from incident light radiation while substantially retaining all other wavelengths of light within the incident radiation comprising: a. providing a light source; b. providing an optical filter comprising at least one complementary matched pair of liquid crystal films having optically negative characteristics, the two films in each pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered around lambda o will be essentially completely transmitted by said pair; and c. directing light from said light source upon said optical filter whereby the emergent light beam contains all the wavelengths of light of the incident radiation with the exception of a wavelength band corresponding to each said complementary matched pair of liquid crystal films.
Claim 8
Independent Claim
159 words
A method for removing at least one wavelength band from incident light radiation while substantially retaining all other wavelengths of light within the incident radiation comprising: a. providing a light source; b. providing an optical filter comprising at least one complementary matched pair of liquid crystal films having optically negative characteristics, the two films in each pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered around lambda o will be essentially completely transmitted by said pair; and c. directing light from said light source upon said optical filter whereby the emergent light beam contains all the wavelengths of light of the incident radiation with the exception of a wavelength band corresponding to each said complementary matched pair of liquid crystal films.
Claim 9
Dependent Claim
28 words
The method as defined in claim 6 whrein said incident light is directed upon said optical filter at an angular incidence of from about 80* to about 100*.
Claim 10
Dependent Claim
20 words
The method as defined in claim 6 wherein said incident light is directed upon said optical filter at normal incidence.
Claim 11
Dependent Claim
29 words
The method as defined in claim 8 wherein lambda o for each said complementary matched pair of liquid crystal films is in the visible region of the light spectrum.
Claim 12
Dependent Claim
32 words
The method as defined in claim 9 wherein each liquid crystal film of each said complementary matched pair of liquid crystal films is from about 3 to about 10 microns in thickness.
Claim 13
Dependent Claim
32 words
The method as defined in claim 6 wherein each liquid crystal film of each said complementary matched pair of liquid crystal films is from about 0.5 to about 20 microns in thickness.
Claim 14
Dependent Claim
78 words
The method as defined in claim 6 wherein each liquid crystal film of each said complementary matched pair of liquid crystal films comprises a composition chosen from the group consisting of: cholesteric liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and nematic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and smectic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and non-liquid crystalline substances which are compatible with cholesteric liquid crystalline substances; and mixtures thereof.
Claim 15
Dependent Claim
150 words
A detection device for indicating the presence of stimuli to which liquid crystal substances having optically negative properties are sensitive comprising an optically transparent and isotropic spacing member carrying on each surface thereof a thin layer of a liquid crystalline substance having optically negative properties, said layers of liquid crystalline substances comprising a complementary matched pair of liquid crystal layers, each of said layers of liquid crystalline substances carrying on the respective surfaces thereof remote from said spacing member a thin layer of an optically transparent material, the two layers in said pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered arOund lambda o will be essentially completely transmitted by said pair.
Claim 16
Dependent Claim
150 words
A detection device for indicating the presence of stimuli to which liquid crystal substances having optically negative properties are sensitive comprising an optically transparent and isotropic spacing member carrying on each surface thereof a thin layer of a liquid crystalline substance having optically negative properties, said layers of liquid crystalline substances comprising a complementary matched pair of liquid crystal layers, each of said layers of liquid crystalline substances carrying on the respective surfaces thereof remote from said spacing member a thin layer of an optically transparent material, the two layers in said pair having the opposite rotatory sense from each other and being arranged so that incident light in the band centered about some wavelength lambda o will be essentially completely reflected by said pair while the remainder of the incident light having wavelengths outside of the band centered arOund lambda o will be essentially completely transmitted by said pair.
Claim 17
Dependent Claim
28 words
The device as defined in claim 13 wherein at least one of said layers of optically transparent material carried by said layers of liquid crystalline substances is flexible.
Claim 18
Dependent Claim
20 words
The device as defined in claim 14 wherein one of said layers of optically transparent material comprises Black Mylar Sheet.
Claim 19
Dependent Claim
30 words
The device as defined in claim 15 wherein the lambda o value of said complementary matched pair of liquid crystal layers is in the visible region of the light spectrum.
Claim 20
Dependent Claim
71 words
The device as defined in claim 13 wherein each layer of liquid crystalline substance comprises a composition chosen from the group consisting of: cholesteric liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and nematic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and smectic liquid crystalline substances; mixtures of cholesteric liquid crystalline substances and non-liquid crystalline substances which are compatible with the cholesteric liquid crystalline substances; and mixtures thereof.
Claim 21
Dependent Claim
30 words
The device as defined in claim 13 wherein the lambda o value of said complementary matched pair of liquid crystal layers is in the visible region of the light spectrum.
Claim 22
Dependent Claim
26 words
The device as defined in claim 18 wherein each of said layers of liquid crystalline substance is from about 3 to about 10 microns in thickness.
Claim 23
Dependent Claim
26 words
The device as defined in claim 13 wherein each of said layers of liquid crystalline substance is from about 0.5 to about 20 microns in thickness.
References Cited (Backward Citations)
US3582225A
Cited
US3592526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |