US3738732A
Expired / Lapsed
US
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Multi-layer antireflection coating
Assignee: Nikon Corp
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Filing: 1970-10-06
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Granted: 1973-06-12
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Expires: 1990-10-06
Abstract
Abstract A quasi-symmetrical three-layer coating of a desired equivalent refractive index N having a wide dispersion effect in the regions adjacent to the visible region is presented. The coating consists of various substances deposited in vacuum in a stable manner. One layer of a quasi-symmetrical three-layer coating is substituted by a glass to be coated. When the glass to be coated has not the refractive index of 1.52 or 1.74, a suitable layer lambda /4 in thickness is coated over said glass.
Inventors
- 👤 H Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:59
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/113; G02B1/115
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
238 words
In an optical component including a body having at least one surface through which light is transmissible, and having an antireflection coating on said one surface, the improvement wherein said anireflection coating comprises five layers of material having optical thicknesses not less than one-quarter of the central wave length lambda s of the coating; the first layer adjacent to the air having an optical thickness of lambda /4 and refractive index n1 of less than 1.39, the second layer adjacent to said first layer having an optical thickness of lambda /2 and refraCtive index n2 of about 2.0, the third and fifth layers having refractive indices of about 1.60 and respective different optical thicknesses, wherein the third layer is disposed adjacent the second layer, the fifth layer is disposed on said one surface of said body, and the fourth layer is disposed between the third and fifth layers; and wherein said third to fifth layers form a quasi-symmetrical three layer anti-reflection member, and said component satisfies the following conditions Delta n3/n3 < 0.2 2n3d3 + n4d4 m/4 lambda s (m 1, 2 . . .) n3d3 n4d4 where Delta n3 is the difference between index n3 of the third layer and index n5 of the fifth layer, d3 and d4 designate actual thicknesses of the third and fourth layers, and n3d3/ lambda s and n4d4/ lambda s designate the optical thicknesses of the third and fourth layers respectively.
Claim 2
Dependent Claim
73 words
An optical component according to claim 2, wherein optical thicknesses of the third, fourth and fifth layers are lambda /2, lambda /2 and lambda /4 respectively, the fourth layer has a refractive index of about 2.0, Delta n3/n3 is about 0.05 and the second, third and fourth layers form a second quasi-symmetrical three-layer member satisfying the relationship Delta n2/n2 0.05 * 0.10, where Delta n2 is the difference between index n2 and n4.
Claim 3
Dependent Claim
38 words
An optical component according to claim 2, wherein the optical thicknesses of the third, fourth and fifth layers are lambda /4, lambda /4 and lambda /2 respectively, and the fourth layer has a refractive index of about 1.60.
Claim 4
Dependent Claim
219 words
In an optical component including a body having at least one surface through which light is transmissible, and having an antireflection coating on said one surface, the improvement wherein said antireflection coating comprises at least four layers of material having optical thicknesses not less than one-quarter of the central wavelength lambda s of the coating; wherein three successive layers of said coating form a quasi-symmetrical three-layer antireflection coating, said three successive layers having respective refraction indices n1, n2, and n3; wherein said indices of the first and third layers of said three successive layers satisfy the relationship Delta n1/n1 < 0.2, where Delta n1 is the difference between index n1 of the first layer and index n 3 of the third layer; and wherein said antireflection coating satisfies the following conditions 2n1d1 + n2d2 m/4 lambda s (m + 1, 2, . . .), n1d1 n2d2, and cos g about (n1/n1+ n2), where d1 and d2 designate actual thicknesses of the first and second layers of said three successive layers, n1d1/ lambda s and n2d2/ lambda s designate the optical thicknesses of the first and second layers, respectively, lambda s is a central wavelength, g (2 pi n1d1/ lambda s) lambda s/ lambda and lambda is an arbitrarily chosen wavelength adjacent to the visible range centered at lambda s.
Claim 5
Dependent Claim
218 words
In an optical component including a body having at least one surface through which light is transmissible, and having an anti-reflection coating on said one surface, the improvement wherein said antireflection coating comprises at least four layers of material having optical thicknesses not less than one-quarter of the central wavelength lambda s of the coating; wherein three successive layers of said coating form a quasi-symmetRical three-layer antireflection coating, said three successive layers having respective refraction indices n1, n2, and n3; wherein said indices of the first and third layers of said three successive layers satisfy the relationship Delta n1n1 < 0.2, where Delta n1 is the difference between index n1 of the first layer and index n3 of the third layer; and wherein said anti-reflection coating satisfies the following conditions 2n1d1 + n2d2 m/4 lambda s (m 1, 2, . . . ) , 2n1d1 n2d2, and tan g about n2/n1, where d1 and d2 designate actual thicknesses of the first and second layers of said three successive layers, n1d1/ lambda s and n2d2/ lambda s designate the optical thicknesses of the first and second layers, respectively, lambda s is a central wavelength, g (2 pi n1d1/ lambda s) lambda s/ lambda and lambda is an arbitrarily chosen wavelength adjacent to the visible range centered at lambda s.
Claim 6
Dependent Claim
223 words
In an optical component including a body having at least one surface through which light is transmissible, and having an anti-reflection coating on said one surface, the improvement wherein said antireflection coating comprises at least four layers of material having optical thicknesses not less than one-quarter of the central wavelength lambda s of the coating; wherein three successive layers of said coating form a quasi-symmetrical three-layer antireflection coating, said three successive layers having respective refraction indices n1, n2, and n3; wherein said indices of the first and third layers of said three successive layers satisfy the relationship Delta n1/n1 < 0.2, where Delta n1 is the difference between index n1 of the first layer and index n3 of the third layer; and wherein said anti-reflection coating satisfies the following conditions 2n1d1 + n2d2 m/4 lambda s ( m 1, 2 . . . . ), n1d1 2n2d2 , and cos g about (1+ (n2)/(n1+n2)2 )1/2 n2/n1n2, where d1 and d2 designate actual thicknesses of the first and second layers of said three successive layers, n1d1/ lambda s and n2d2/ lambda s designate the optical thicknesses of the first and second layers, respectively, lambda s is a central wavelength, g 2 pi n1d1/ lambda s) lambda s/ lambda and lambda is an arbitrarily chosen wavelength adjacent to the visible range centered at lambda s.
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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |