US3847585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preparation of multilayer optical filters
Assignee: Dow Chemical Co
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Filing: 1973-01-08
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Granted: 1974-11-12
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Expires: 1993-01-08
Abstract
Abstract Optical filters are prepared from transparent glasses by the formation of multilayer streams of molten glass. The optical filter is formed by flowing molten first and second glass compositions substreams and interdigitating the substreams into a composite stream on a bath and shaping the composite stream that the interfaces of the substreams are parallel to the major surface of the composite stream. By choice of layer thickness reflection can be obtained in infrared, visible ultraviolet range.
Inventors
- 👤 D Chisholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:16
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285; C; C03; C03B; C03B17/00; C03B17/02; C03B18/00; C03B18/02; C03B18/12; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
128 words
A method for the preparation of a multilayer optical filter, the steps of the method comprising providing at least first and second thermoplastic transparent glass compositions, dividing the first and second glass compositions into first and second substreams, interdigitating the first and second substreams to provide a single composite stream, deforming the single composite stream to alternate the shape of the substreams to provide the substreams with a plurality of interfaces, the interfaces being deposited in generally parallel planes which are parallel to a major surface of the composite stream and being separated by a distance from about 0.05 micron to about one micron, with the further limitation that the first and second glass compositions have refractive indices which differ from each other by at least about 0.05.
Claim 2
Independent Claim
128 words
A method for the preparation of a multilayer optical filter, the steps of the method comprising providing at least first and second thermoplastic transparent glass compositions, dividing the first and second glass compositions into first and second substreams, interdigitating the first and second substreams to provide a single composite stream, deforming the single composite stream to alternate the shape of the substreams to provide the substreams with a plurality of interfaces, the interfaces being deposited in generally parallel planes which are parallel to a major surface of the composite stream and being separated by a distance from about 0.05 micron to about one micron, with the further limitation that the first and second glass compositions have refractive indices which differ from each other by at least about 0.05.
Claim 3
Dependent Claim
80 words
The method of claim 1 wherein the first and second glass compositions are interdigitated to form a stream having a plurality of alternating strips of the first and second compositions in side by side relationship, subsequently compressing the composite stream in the direction of its width and expanding the stream in the direction of its thickness to thereby provide a composite glass stream having a plurality of layers therein extending generally parallel to a major surface of the composite stream.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the composite stream is floated on the surface of a bath.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the composite stream is stretched to provide interfaces having the desired spacing therebetween.
Claim 6
Dependent Claim
27 words
The method of claim 1 including the step of providing at least one layer of the finished composite stream having a thickness greater than about one micron.
Claim 7
Dependent Claim
19 words
The method of claim 1 including the step of providing surface layers having thicknesses greater than about one micron.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |