Patent US3711181A successfully refreshed from Google Patents.
US3711181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical notch filter
Assignee: Xerox Corp
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Filing: 1971-03-05
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Granted: 1973-01-16
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Expires: 1991-03-05
Abstract
Abstract An optical filter system capable of transmitting light at substantially all wavelengths of incident radiation while simultaneously rejecting radiation at a single wavelength band or plurality of wavelength bands within the incident radiation is described. The system employs optically negative liquid crystal films which are the same in intrinsic rotatory sense and means for converting circularly polarized light of one sense, e.g., right handed, to circularly polarized light of the opposite sense, e.g., left handed.
Inventors
- 👤 J Adams
- 👤 J Dailey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:21
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/12; G02; G02B; G02B5/00; G02B5/30; G02B5/3016; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
43 words
An optical apparatus comprising at least one optical filter, each said optical filter comprising means for converting circularly polarized light of one sense to circularly polarized light of the opposite sense arranged between a cooperative matched pair of optically negative liquid crystal films.
Claim 2
Dependent Claim
43 words
An optical apparatus comprising at least one optical filter, each said optical filter comprising means for converting circularly polarized light of one sense to circularly polarized light of the opposite sense arranged between a cooperative matched pair of optically negative liquid crystal films.
Claim 3
Dependent Claim
24 words
The optical apparatus defined in claim 1 wherein lambda Omicron for each said optical filter is in the visible region of the light spectrum.
Claim 4
Dependent Claim
29 words
ThE optical apparatus as defined in claim 1 wherein each individual liquid crystal film of each said optical filter is from about 0.5 to about 20 microns in thickness.
Claim 5
Dependent Claim
29 words
The optical apparatus as defined in claim 2 wherein each individual liquid crystal film of each said optical filter is from about 3 to about 10 microns in thickness.
Claim 6
Dependent Claim
75 words
The optical apparatus as defined in claim 1 wherein each individual liquid crystal film of each said optical filter comprises a composition selected 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
Dependent Claim
28 words
The optical apparatus as defined in claim 1 wherein the individual liquid crystal films of at least one of said optical filters comprise the same liquid crystalline substance.
Claim 8
Dependent Claim
27 words
The optical apparatus as defined in claim 1 wherein the individual liquid crystal films of at least one of said optical filters comprise different liquid crystalline substances.
Claim 9
Independent Claim
117 words
A method for removing at least one wavelength band from incident light radiation while retaining substantially all other wavelengths of light within the incident radiation comprising: a. providing a light source; b. providing an optical apparatus comprising at least one optical filter each said optical filter comprising means for converting circularly polarized light of one sense to circularly polarized light of the opposite sense arranged between a cooperative matched pair of optically negative liquid crystal films; and c. directing light from said light source upon said optical apparatus whereby the emergent light beam contains substantially all the wavelengths of light of the incident radiation with the exception of a wavelength band corresponding to each said optical filter.
Claim 10
Independent Claim
117 words
A method for removing at least one wavelength band from incident light radiation while retaining substantially all other wavelengths of light within the incident radiation comprising: a. providing a light source; b. providing an optical apparatus comprising at least one optical filter each said optical filter comprising means for converting circularly polarized light of one sense to circularly polarized light of the opposite sense arranged between a cooperative matched pair of optically negative liquid crystal films; and c. directing light from said light source upon said optical apparatus whereby the emergent light beam contains substantially all the wavelengths of light of the incident radiation with the exception of a wavelength band corresponding to each said optical filter.
Claim 11
Dependent Claim
20 words
The method as defined in claim 8 wherein said incident light is directed upon said optical apparatus at normal incidence.
Claim 12
Dependent Claim
29 words
The method as defined in claim 8 wherein said incident light is directed upon said optical apparatus at an angular incidence of from about 80* to about 100* .
Claim 13
Dependent Claim
24 words
The method as defined in claim 8 wherein lambda Omicron for each said optical filter is in the visible region of the light spectrum.
Claim 14
Dependent Claim
28 words
The method as defined in claim 8 wherein each individual liquid crystal film of each said optical filter is from about 0.5 to about 20 microns in thickness.
Claim 15
Dependent Claim
28 words
The method as defined in claim 11 wherein each individual liquid crystal film of each said optical filter is from about 3 to about 10 microns in thickness.
Claim 16
Dependent Claim
74 words
The method as defined in claim 8 wherein each individual liquid crystal film of each said optical filter comprises a composition selected 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 17
Dependent Claim
27 words
The method as defined in claim 8 wherein the individual liquid crystal films of at least one of said optical filters comprise the same liquid crystalline substance.
Claim 18
Dependent Claim
26 words
The method as defined in claim 8 wherein the individual liquid crystal films of at least one of said optical filters comprise different liquid crystalline substances.
References Cited (Backward Citations)
US3114836A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |