Patent US4627688A successfully refreshed from Google Patents.
US4627688A
Expired / Lapsed
US
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Beam splitter
Assignee: Sano Kiko Co Ltd
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Filing: 1985-11-20
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Granted: 1986-12-09
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Expires: 2005-11-20
Abstract
Abstract A beam splitter comprises a transparent substrate having a refractive index N S , at least one low refractive index film layer having a refractive index N L higher than N S , and at least one high refractive index film layer having a refractive index N H higher than N L . The low refractive index film layer and the high refractive index film layer are alternately stacked on the substrate so that the lowermost film layer and the uppermost film layer of the stack are the low refractive index film layer, or the lowermost film layer is the high refractive index film layer and the uppermost film layer is the low refractive index film layer.
Inventors
- 👤 Takeshi Kobayashi
- 👤 Kazuo Endo
- 👤 Nobumasa Nanbu
- 👤 Yoshizi Kawamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:13
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/142; G02B27/28; G02B27/283; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1356
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
120 words
A beam splitter consisting essentially of a transparent substrate having a refractive index N S , one or more low refractive index film layers, each low refractive index film layer having a refractive index N L higher than said refractive index N S , and one or more high refractive index film layers, each high refractive index film layer having a refractive index N H higher than said refractive index N L , whereby N S <N L <N H , said low refractive index film layer and said high refractive index film layer being alternately stacked on said transparent substrate in such a manner that the uppermost film layer of the stack is the low refractive index film layer.
Claim 2
Dependent Claim
120 words
A beam splitter consisting essentially of a transparent substrate having a refractive index N S , one or more low refractive index film layers, each low refractive index film layer having a refractive index N L higher than said refractive index N S , and one or more high refractive index film layers, each high refractive index film layer having a refractive index N H higher than said refractive index N L , whereby N S <N L <N H , said low refractive index film layer and said high refractive index film layer being alternately stacked on said transparent substrate in such a manner that the uppermost film layer of the stack is the low refractive index film layer.
Claim 3
Dependent Claim
24 words
A beam splitter as defined in claim 1 wherein also the lowermost film layer of said stack is the low refractive index film layer.
Claim 4
Dependent Claim
38 words
A beam splitter as defined in claim 2 wherein said refractive index N S satisfies the condition of 1.3<N.sub.S <4, and said refractive indices N H and N L satisfy the conditions of 2.5<N.sub.H <8, and 1.6<N.sub.L <5.
Claim 5
Dependent Claim
31 words
A beam splitter as defined in claim 2 or 3 wherein the optical film thickness of each film layer is substantially λ 0 /4, where λ 0 is the design wavelength.
Claim 6
Dependent Claim
37 words
A beam splitter as defined in claim 2 or 3 wherein said transparent substrate is in the prism form, and said uppermost film layer of said stack is adhered to a prism block via an adhesive layer.
Claim 7
Dependent Claim
73 words
A beam splitter as defined in claim 1 wherein said transparent substrate is in plate form and positioned in air having a refractive index N O of 1.0, and said low refractive index film layer and said high refractive index film layer are alternately stacked on said transparent substrate in such a manner that the lowermost film layer and the uppermost film layer of the stack are the low refractive index film layers.
Claim 8
Dependent Claim
38 words
A beam splitter as defined in claim 6 wherein said refractive index N S satisfies the condition of 1.3<N.sub.S <4, and said refractive indices N H and N L satisfy the conditions of 1.8<N.sub.H <5, and 1.4<N.sub.L <3.
Claim 9
Dependent Claim
29 words
A beam splitter as defined in claim 6 or 7 wherein the optical film thickness of each film layer is substantially λ/4, where λ 0 is the design wavelength.
Claim 10
Dependent Claim
83 words
A beam splitter as defined in claim 1 wherein said transparent substrate is in plate form and positioned in air having a refractive index N O of 1.0, and said low refractive index film layer and said high refractive index film layer are alternately stacked on said transparent substrate in such a manner that the lowermost film layer of the stack is the high refractive index film layer and the uppermost film layer of the stack is the low refractive index film layer.
Claim 11
Dependent Claim
38 words
A beam splitter as defined in claim 9 wherein said refractive index N S satisfies the condition of 1.3<N.sub.S <4, and said refractive indices N H and N L satisfy the conditons of 1.8<N.sub.H <6, and 1.4<N.sub.L <3.
Claim 12
Dependent Claim
31 words
A beam splitter as defined in claim 9 or 10 wherein the optical film thickness of each film layer is substantially λ 0 /4, where λ 0 is the design wavelength.
Claim 13
Dependent Claim
130 words
A beam splitter for splitting a light beam that consists principally of a single wavelength consisting essentially of a transparent substrate having a refractive index N S and a plurality of film layers one atop the next each having a refractive index higher than the refractive index N S , including at least one low refractive index film layer having a refractive index N L higher than said refractive index N S , and at least one high refractive index film layer having a refractive index N H higher than said refractive index N L , said low refractive index film layer and said high refractive index film layer being stacked on said substrate such that the uppermost film layer of the stack is the low refractive index film layer.
Claim 14
Dependent Claim
130 words
A beam splitter for splitting a light beam that consists principally of a single wavelength consisting essentially of a transparent substrate having a refractive index N S and a plurality of film layers one atop the next each having a refractive index higher than the refractive index N S , including at least one low refractive index film layer having a refractive index N L higher than said refractive index N S , and at least one high refractive index film layer having a refractive index N H higher than said refractive index N L , said low refractive index film layer and said high refractive index film layer being stacked on said substrate such that the uppermost film layer of the stack is the low refractive index film layer.
Claim 15
Dependent Claim
29 words
A beam splitter as defined in claim 12, wherein the optical film thickness of each film layer is substantially λ 0 /4, where λ 0 is the design wavelength.
References Cited (Backward Citations)
US4415233A
Cited
US4431258A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-08 | 1990-06-09 | 1990-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-08 | 1994-06-09 | 1994-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-08 | 1998-06-09 | 1998-12-09 | $7700.00 | Window Closed / Lapsed |