Patent US3637295A successfully refreshed from Google Patents.
US3637295A
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Achromatic lens system
Assignee: Nippon Selfoc Co Ltd
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Filing: 1969-12-29
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Granted: 1972-01-25
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Expires: 1989-12-29
Abstract
Abstract An achromatic lens system comprising a lens system which includes at least one lens whose refractive index changes substantially proportional to the square of the distance from a central axis of the lens toward the surface thereof and whose both end planes are perpendicular to said central axis, lenses constituting said lens system being disposed in coaxial relation so as to substantially eliminate the chromatic aberration of the lens system.
Inventors
- 👤 Hiroyoshi Matsumura
- 👤 Shogo Yoshikawa
- 👤 Ryuji Tatsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:54
CPC Classifications
G; G02; G02B; G02B3/00; G02B13/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
125 words
An achromatic lens system comprising a first lens whose focal distance and Abbe''s number are respectively f1 and A1 and a second lens whose focal distance and Abbe''s number are respectively f2 and A2, at least one lens of both of the first lens and second lens having a refractive index which changes substantially proportionally to the square of the distance from the central axis of the lens toward the surface thereof and whose both end planes are perpendicular to said central axes, the first lens and second lens being disposed in a coaxial relation so that the distance D from the second principal plane of the first lens to the first principal plane of the second lens substantially satisfies the following equation: D (A1f1+A2f2)/(A1+A2).
Claim 2
Dependent Claim
125 words
An achromatic lens system comprising a first lens whose focal distance and Abbe''s number are respectively f1 and A1 and a second lens whose focal distance and Abbe''s number are respectively f2 and A2, at least one lens of both of the first lens and second lens having a refractive index which changes substantially proportionally to the square of the distance from the central axis of the lens toward the surface thereof and whose both end planes are perpendicular to said central axes, the first lens and second lens being disposed in a coaxial relation so that the distance D from the second principal plane of the first lens to the first principal plane of the second lens substantially satisfies the following equation: D (A1f1+A2f2)/(A1+A2).
Claim 3
Dependent Claim
97 words
An achromatic lens system according to claim 1, in which both of said lenses have a refractive index which changes substantially proportionally to the square of the distance from the central axis of the lens toward the surface thereof, said first and second lenses being attached closely so as to substantially satisfy the following equation: h1+h2 (A1f1+A2f2)/(A1+A2) where h1 is a distance from the first principal plane of the first lens to the first end plane thereof, and h2 is a distance from the first principal plane of the second lens to the first end plane thereof.
References Cited (Backward Citations)
US3403348A
Cited
US3486808A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |