US4647159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gradient index type single lens
Assignee: Canon Inc
•
Filing: 1984-12-26
•
Granted: 1987-03-03
•
Expires: 2004-12-26
Abstract
Abstract In a gradient index type single lens having a gradient index in a direction perpendicular to the optic axis thereof, the surface of the single lens on the light beam incidence side when the single lens is used at a reduced magnification forms a planar surface, the surface of the single lens on the light beam emergence side forms a convex surface and are satisfied the following conditions: 0.55≦(1-N.sub.0)·f/r.sub.2 ≦1.20 0.8≦d/f≦2.2 where r 2 is the radius of curvature of the surface on said light beam emergence side, d is the thickness of the single lens, N 0 is the on-axis refractive index of the single lens, and f is the focal length of the single lens.
Inventors
- 👤 Takeshi Baba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:14
CPC Classifications
G; G02; G02B; G02B3/00; G02B3/0087
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
119 words
A gradient index type single lens having an gradient index in a direction perpendicular to the optic axis thereof, wherein the surface of said single lens on the light beam incidence side when said single lens is used at a reduced magnification forms a planar surface and the surface of said single lens on the light beam emergence side forms a convex surface, said single lens satisfying the following conditions: 0.55≦(1-N.sub.0)·f/r.sub.2 ≦1.20 0.8≦d/f≦2.2 where r 2 is the radius of curvature of the surface on said light beam emergence side, d is the thickness of said single lens, N 0 is the on-axis refractive index of said single lens, and f is the focal length of said single lens.
Claim 2
Dependent Claim
119 words
A gradient index type single lens having an gradient index in a direction perpendicular to the optic axis thereof, wherein the surface of said single lens on the light beam incidence side when said single lens is used at a reduced magnification forms a planar surface and the surface of said single lens on the light beam emergence side forms a convex surface, said single lens satisfying the following conditions: 0.55≦(1-N.sub.0)·f/r.sub.2 ≦1.20 0.8≦d/f≦2.2 where r 2 is the radius of curvature of the surface on said light beam emergence side, d is the thickness of said single lens, N 0 is the on-axis refractive index of said single lens, and f is the focal length of said single lens.
Claim 3
Dependent Claim
23 words
A gradient index type single lens according to claim 1, wherein said d and said r 2 satisfy the relation that 0.45≦|r.sub.2 /d|≦0.58.
References Cited (Backward Citations)
JPS6354A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |