US4616902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite filter, observation system and filamentary display device
Assignee: Individual
•
Filing: 1984-07-10
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Granted: 1986-10-14
•
Expires: 2004-07-10
Abstract
Abstract A composite filter (i) which transmits starlight radiation having a wavelength of 400 up to but not including 600 nm and (ii) does not transmit radiation having a wavelength of 600 to 900 nm comprising at least one organic film filter and at least one glass filter, in which said organic film filter absorbs light radiation having a wavelength of 600-700 nm and said glass filter comprises a glass plate colored with a cobalt-containing salt which absorbs light radiation having a wavelength of 700-900 nm.
Inventors
- 👤 Kiyoshi Nagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:34
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/208; G02B5/22; G02B5/223; G02B5/226
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
A composite filter (i) which transmits starlight radiation having a wavelength of 400 up to but not including 600 nm and (ii) does not transmit radiation having a wavelength of 600 to 900 nm comprising at least one organic film filter and at least one glass filter, in which said organic film filter absorbs light radiation having a wavelength of 600-700 nm and said glass filter comprises a glass plate colored with a cobalt-containing salt which absorbs light radiation having a wavelength of 700-900 nm.
Claim 2
Dependent Claim
85 words
A composite filter (i) which transmits starlight radiation having a wavelength of 400 up to but not including 600 nm and (ii) does not transmit radiation having a wavelength of 600 to 900 nm comprising at least one organic film filter and at least one glass filter, in which said organic film filter absorbs light radiation having a wavelength of 600-700 nm and said glass filter comprises a glass plate colored with a cobalt-containing salt which absorbs light radiation having a wavelength of 700-900 nm.
Claim 3
Dependent Claim
19 words
The composite filter as claimed in claim 1, in which said organic film filter comprises a dyed cellulose derivative.
Claim 4
Dependent Claim
24 words
The composite filter as claimed in claim 2, in which said dyed cellulose derivative is a dyed cellulose diacetate or a dyed cellulose triacetate.
Claim 5
Dependent Claim
22 words
The composite filter as claimed in claim 1, in which said organic filter has a thickness in the range of 0.01-2 mm.
Claim 6
Dependent Claim
19 words
The composite filter as claimed in claim 1, in which said glass filter has a thickness of 0.1-10 mm.
Claim 7
Dependent Claim
21 words
The composite filter as claimed in claim 1, in which said glass filter is a phosphate glass containing a cobalt-containing salt.
Claim 8
Dependent Claim
40 words
The composite filter as claimed in claim 1, in which said organic filter has a thickness in the range of 0.01-2 mm, said glass filter has a thickness of 0.1-10 mm and is a phosphate glass containing a cobalt-containing salt.
Claim 9
Dependent Claim
19 words
The composite filter as claimed in claim 7, in which said organic film filter comprises a dyed cellulose derivative.
Claim 10
Dependent Claim
24 words
The composite filter as claimed in claim 8, in which said dyed cellulose derivative is a dyed cellulose diacetate or a dyed cellulose triacetate.
References Cited (Backward Citations)
US2418605A
Cited
US2525638A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-13 | 1990-04-14 | 1990-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-13 | 1994-04-14 | 1994-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-13 | 1998-04-14 | 1998-10-14 | $7700.00 | Window Closed / Lapsed |