US3804491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer reflection proof film
Assignee: Olympus Corp
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Filing: 1972-08-15
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Granted: 1974-04-16
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Expires: 1992-08-15
Abstract
Abstract A multilayer anti-reflection film for use in high class camera lenses, microscope objective lenses, etc. has an antinonhomogeneous film held between a reflective film and a glass substrate and having a refractive index continuously changing in a direction perpendicular to said film and toward the outermost film from a refractive index which is equal to the refractive index of the glass substrate. The continuous change of refractive index of the nonhomogeneous film is effected by continuously changing a mixing ratio of the amount of vapors produced when both materials having large and small refractive indexes are vapor deposited on the glass substrate.
Inventors
- 👤 T Morokuma
- 👤 T Kozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:00
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; G02B1/115
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A multilayer anti-reflection film as claimed in claim 1 wherein one side of said nonhomogeneous film which has a large refractive index is formed of a mixture of compounds selected from the group consisting of MgF2, CeF2 and CeO2 and the other side of said nonhomogeneous film which has a small refractive index is formed of a material selected from the group consisting of MgF2, NaF, cryolite, and mixtures thereof, said continuous change of the refractive index in the direction perpendicular to said nonhomogeneous film and toward the outermost film being effected by continuously changing a mixing ratio of the amount of vapors produced when both the materials having large and small refractive indexes are vapor deposited on said glass substrate.
Claim 2
Dependent Claim
78 words
A multilayer anti-reflection film as claimed in claim 1 wheRein the refractive index of said nonhomogeneous film is continuously changing in a direction perpendicular to said nonhomogeneous film and toward the outermost film from a refractive index which is equal to the refractive index of said glass substrate to a refractive index which is smaller than the refractive index of said glass substrate and said anti-reflection film coated on said nonhomogeneous film consists of at least three layers.
Claim 3
Dependent Claim
119 words
A multilayer anti-reflection film as claimed in claim 3 wherein said anti-reflection film consists of three layers having refractive indexes n1, n2 and n3, respectively, and the smaller refractive index ns of said nonhomogeneous film is decreased to a refractive index between ns 1.30 and ns 1.40 and the refractive indexes n1, n2 and n3 and the thicknesses d1, d2 and d3 of the first, second and third layers of the anti-reflection film counted from the top thereof are given by n1 1.38, n1d1 125 m Mu ; n2 2.24, n2d2 250 m Mu ; and n3 n1 Square Root ns, n3d3 125 m Mu , respectively, the refractive index nB of the glass substrate being larger than ns.
Claim 4
Dependent Claim
119 words
A multilayer anti-reflection film as claimed in claim 3 wherein said anti-reflection film consists of three layers having refractive indexes n1, n2 and n3, respectively, and the smaller refractive index ns of said nonhomogeneous film is decreased to a refractive index between ns 1.30 and ns 1.40 and the refractive indexes n1, n2 and n3 and the thicknesses d1, d2 and d3 of the first, second and third layers of the anti-reflection film counted from the top thereof are given by n1 1.38, n1d1 125 m Mu ; n2 2.1, n2d2 250 m Mu ; and n3 n1 Square Root ns, n3d3 125 m Mu , respectively, the refractive index nB of the glass substrate being larger than ns.
Claim 5
Dependent Claim
75 words
A multilayer anti-reflection film as claimed in claim 1 wherein the refractive index of said nonhomogeneous film is continuously changing in a direction perpendicular to said film and toward the outermost film from a refractive index which is equal to the refractive index of said glass substrate to a refractive index which is larger than the refractive index of said glass substrate, and said anti-reflection film coated on said nonhomogeneous film consists of two layers.
Claim 6
Dependent Claim
104 words
A multilayer anti-reflection film as claimed in claim 6 wherein said anti-reflection film consists of two layers having refractive indexes n1 and n2, respectively, and the larger refractive index ns of said nonhomogeneous film is enlarged to a refractive index between ns 1.75 and ns 1.90, and the refractive indexes n1 and n2 and the thicknesses d1 and d2 of the first and second layers of the anti-reflection film counted from the top thereof are given by n1 1.39, n1d1 125 m Mu and n2 2.08, n2d2 250 m Mu , respectively, the refractive index nB of the glass substrate being smaller than ns.
References Cited (Backward Citations)
US3176574A
Cited
US3706485A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |