Patent US4810070A successfully refreshed from Google Patents.
US4810070A
Expired / Lapsed
US
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Lens system having a good image performance for white light
Assignee: Canon Inc
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Filing: 1986-08-26
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Granted: 1989-03-07
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Expires: 2006-08-26
Abstract
Abstract A lens system has a lens unit comprising a positive lens and a negative lens. The positive lens has an index distribution in the direction of the optic axis. The value of the index gradient for a light having a short wavelength in the vicinity of the vertex of at least one convex surface of the positive lens is smaller than the value of the index gradient for a light having a long wavelength.
Inventors
- 👤 Shigeyuki Suda
- 👤 Jun Hattori
- 👤 Nozomu Kitagishi
- 👤 Hiroki Nakayama
- 👤 Akihisa Horiuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:30
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0087; G02B15/00; G02B15/14; G02B15/144; G02B15/1441
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
A lens unit comprising a positive lens and a negative lens disposed adjacent to each other, said positive lens having an index distribution in the direction of the optic axis, said position lens having a convex surface, the index gradient for a light having a short wavelength being smaller than the index gradient for a light having a long wavelength in the vicinity of the vertex of said convex surface.
Claim 2
Dependent Claim
70 words
A lens unit comprising a positive lens and a negative lens disposed adjacent to each other, said positive lens having an index distribution in the direction of the optic axis, said position lens having a convex surface, the index gradient for a light having a short wavelength being smaller than the index gradient for a light having a long wavelength in the vicinity of the vertex of said convex surface.
Claim 3
Dependent Claim
12 words
A lens unit according to claim 1, having a positive composite power.
Claim 4
Dependent Claim
12 words
A lens unit according to claim 2, which is a collimator lens.
Claim 5
Dependent Claim
21 words
A lens unit according to claim 1, wherein said positive lens and said negative lens are adhesively secured to each other.
Claim 6
Dependent Claim
25 words
A lens unit according to claim 4, wherein said positive lens is of a biconvex shape and said negative lens is of a biconcave shape.
Claim 7
Dependent Claim
78 words
A lens system having a plurality of lens units, one of said lens unit being provided with a positive lens and a negative lens, said positive lens having an index distribution in the direction of the optic axis, said positive lens having a convex surface, the index gradient for a light having a short wavelength being smaller than the index gradient for a light having a long wavelength in the vicinity of the vertex of said convex surface.
Claim 8
Dependent Claim
78 words
A lens system having a plurality of lens units, one of said lens unit being provided with a positive lens and a negative lens, said positive lens having an index distribution in the direction of the optic axis, said positive lens having a convex surface, the index gradient for a light having a short wavelength being smaller than the index gradient for a light having a long wavelength in the vicinity of the vertex of said convex surface.
Claim 9
Dependent Claim
12 words
A lens system according to claim 6, which is a zoom lens.
Claim 10
Dependent Claim
24 words
A lens system according to claim 7, wherein the lens unit provided with the positive lens having an index distribution is a focusing lens.
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) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |