US4721369A
Expired / Lapsed
US
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Gradient index single lens
Assignee: Canon Inc
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Filing: 1986-09-17
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Granted: 1988-01-26
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Expires: 2006-09-17
Abstract
Abstract A gradient index single lens has a first surface convex toward the object side, the first surface lying on the object side when the lens is used at a reduction magnification, a second surface concave toward the image side, the second surface lying on the image side when the lens is used at a reduction magnification, and an index distribution formed in the interior of the lens, the index distribution having a sphere symmetrical distribution about a certain point on the optic axis.
Inventors
- 👤 Jun Hattori
- 👤 Shigeyuki Suda
- 👤 Rohra Aruna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:40
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0087
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
82 words
A gradient index single lens having: a first surface convex toward the object side, said first surface lying on the object side when said lens is used at a reduction magnification; a second surface concave toward the image side, said second surface lying on the image side when said lens is used at a reduction magnification; and an index distribution formed in the interior of said lens, said index distribution having a sphere-symmetrical distribution about a certain point on the optical axis.
Claim 2
Dependent Claim
82 words
A gradient index single lens having: a first surface convex toward the object side, said first surface lying on the object side when said lens is used at a reduction magnification; a second surface concave toward the image side, said second surface lying on the image side when said lens is used at a reduction magnification; and an index distribution formed in the interior of said lens, said index distribution having a sphere-symmetrical distribution about a certain point on the optical axis.
Claim 3
Dependent Claim
55 words
A gradient index single lens according to claim 1, satisfying the following conditions: 1.0≦f/r.sub.1 ≦1.8 0<f/r.sub.1 ≦1.9 0.2≦d/f≦1.5 where r 1 and r 2 are the radii of curvature of said first surface and said second surface, respectively, d is the on-axis thickness of said lens, and f is the focal length of said lens.
Claim 4
Dependent Claim
15 words
A gradient index single lens according to claim 2, further satisfying the following condition: ##EQU4##
Claim 5
Dependent Claim
136 words
A gradient index single lens having: a first surface convex toward the object side, said first surface lying on the object side when said lens is used at a reduction magnification; a second surface concave toward the image side, said second surface lying on the image side when said lens is used at a reduction magnification; and an index distribution fdrmed in the interior of said lens, said index distribution having a sphere-symmetrical distribution about the vicinity of the vertex of said first surface or said second surface; said lens satisfying the following conditions: 1.0≦f/r.sub.1 ≦1.8 0<f/r.sub.2 <1.9 0.2≦d/f≦1.5 where r 1 and r 2 are the radii of curvature of said first surface and said second surface, respectively, d is the on-axis thickness of said lens, and f is the focal length of said lens.
Claim 6
Dependent Claim
136 words
A gradient index single lens having: a first surface convex toward the object side, said first surface lying on the object side when said lens is used at a reduction magnification; a second surface concave toward the image side, said second surface lying on the image side when said lens is used at a reduction magnification; and an index distribution fdrmed in the interior of said lens, said index distribution having a sphere-symmetrical distribution about the vicinity of the vertex of said first surface or said second surface; said lens satisfying the following conditions: 1.0≦f/r.sub.1 ≦1.8 0<f/r.sub.2 <1.9 0.2≦d/f≦1.5 where r 1 and r 2 are the radii of curvature of said first surface and said second surface, respectively, d is the on-axis thickness of said lens, and f is the focal length of said 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) | 1991-01-25 | 1991-07-27 | 1992-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-25 | 1995-07-27 | 1996-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-25 | 1999-07-27 | 2000-01-26 | $7700.00 | Window Closed / Lapsed |