Patent US4634223A successfully refreshed from Google Patents.
US4634223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prism with no detrimental internal reflection
Assignee: Fujifilm Holdings Corp
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Filing: 1985-06-06
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Granted: 1987-01-06
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Expires: 2005-06-06
Abstract
Abstract A prism partly of a solid glass block enclosed with inoperative planes is provided on the inoperative planes with transparent members each of which comprises a light transmission part and a light attenuation part having a great number of either superfine prismatic protuberances or small acute indentations formed over the whole outer surface thereof. The transparent member has a refractive index of n 1 which satisfies the following condition: n.sub.1 ≧n.sub.0 -0.03 wherein n 0 is the refractive index of the prism. A ray of light incident upon the polished surface of the inoperative plane at an angle less than a critical angle passes the through transmission part and then is gradually attenuated as it is repeatedly reflected by the internal surfaces of the prismatic protuberance.
Inventors
- 👤 Toshio Ishii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:47
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
105 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism and having a refractive index of n 0 ; and transparent members having a refractive index of n 1 which are cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side and satisfying the following condition: n.sub.1 ≧n.sub.0 -0.03, said light attenuation part having a great number of either superfine prismatic protuberances or fine acute indentations formed over the whole outer surface thereof, said outer surface being made flat by being coated with a light opaque material.
Claim 2
Dependent Claim
105 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism and having a refractive index of n 0 ; and transparent members having a refractive index of n 1 which are cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side and satisfying the following condition: n.sub.1 ≧n.sub.0 -0.03, said light attenuation part having a great number of either superfine prismatic protuberances or fine acute indentations formed over the whole outer surface thereof, said outer surface being made flat by being coated with a light opaque material.
Claim 3
Dependent Claim
15 words
A prism as defined in claim 1, in which said transparent member is integrally molded.
Claim 4
Dependent Claim
54 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism; transparent members having a higher index of refraction than said solid block, said transparent members being cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side.
Claim 5
Dependent Claim
54 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism; transparent members having a higher index of refraction than said solid block, said transparent members being cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side.
Claim 6
Dependent Claim
79 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism and having a refractive index of n 0 ; and transparent members having a refractive index of n 1 which are cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side and satisfying the following condition: n.sub.1 ≧n.sub.0 -0.03, said solid block being glass and said transparent members being acrylic resin.
Claim 7
Dependent Claim
79 words
A transparent prism enclosed by operative planes and inoperative planes, said prism comprising: a solid block forming said prism and having a refractive index of n 0 ; and transparent members having a refractive index of n 1 which are cemented to said inoperative planes; each of said transparent members having a light attenuation part on its outer side and satisfying the following condition: n.sub.1 ≧n.sub.0 -0.03, said solid block being glass and said transparent members being acrylic resin.
References Cited (Backward Citations)
US19070A
Cited
USRE19070E
Cited
GB416509A
Cited
US2773411A
Cited
US3603670A
Cited
US3648056A
Cited
US3984157A
Cited
US4093354A
Cited
US4165920A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-05 | 1998-07-07 | 1999-01-06 | $7700.00 | Window Closed / Lapsed |