Patent US5337012A successfully refreshed from Google Patents.
Patent US4786151A successfully refreshed from Google Patents.
US4786151A
Expired / Lapsed
US
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Scanning lens system for a light beam scanning device
Assignee: Minolta Co Ltd
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Filing: 1988-01-11
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Granted: 1988-11-22
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Expires: 2008-01-11
Abstract
Abstract A scanning lens system for a light beam scanning device in which a light beam emitted from a light source is shaped by a beam shaping optical element into a linear image to enter a surface of a deflection member and the beam deflected by the deflection member is restored to a circular-like image and projected onto an objective surface by the scanning lens system. The scanning lens system consisting of from the deflection member side a first, second and third single lens, the first single lens being a spherical lens with a positive refractive power, the second single lens being a toric lens with a negative refractive power in a scanning plane and with a positive refractive power in a plane perpendicular to the scanning plane, and the third single lens being a spherical lens with a positive refractive power.
Inventors
- 👤 Akiyoshi Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:42
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/0005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A scanning lens system for a light beam scanning device in which a light beam emitted from a light source is shaped by a beam shaping optical element into a linear image to enter a surface of a deflection member and the beam deflected by the deflection member is restored to a circular-like image and projected onto an objective surface by the scaning lens system, the scanning lens system consisting of from the deflection member side a first, second and third single lens, the first single lens being a spherical lens with a positive refractive power, the second single lens being a toric lens with a negative refractive power in a scanning plane and with a positive refractive power in a plane perpendicular to the scanning plane, and the third single lens being a spherical lens with a positive refractive power.
Claim 2
Dependent Claim
141 words
A scanning lens system for a light beam scanning device in which a light beam emitted from a light source is shaped by a beam shaping optical element into a linear image to enter a surface of a deflection member and the beam deflected by the deflection member is restored to a circular-like image and projected onto an objective surface by the scaning lens system, the scanning lens system consisting of from the deflection member side a first, second and third single lens, the first single lens being a spherical lens with a positive refractive power, the second single lens being a toric lens with a negative refractive power in a scanning plane and with a positive refractive power in a plane perpendicular to the scanning plane, and the third single lens being a spherical lens with a positive refractive power.
Claim 3
Dependent Claim
34 words
A scanning lens system as claimed in claim 1, wherein the second single lens is a toroidal lens having the center point of the surface curvatures near the deflection point on the deflection member.
Claim 4
Dependent Claim
53 words
A scanning lens system as claimed in claim 2 fulfilling the following condition: ##EQU2## wherein l is a length between the deflection point on the deflection member and the center of curvature of the second lens surfaces and f M is a focal length of the scanning lens system in the scanning direction.
Claim 5
Dependent Claim
42 words
A scanning lens system as claimed in claim 2 fulfilling the following condition: ##EQU3## wherein f 1 is a focal length of the first single lens and f M is a focal length of the scanning lens system in the scanning direction.
Claim 6
Dependent Claim
64 words
A scanning lens system as claimed in claim 2 fulfilling the following conditions: ##EQU4## wherein l is a length between the deflection point on the deflection member and the center of curvature of the second lens surfaces, f 1 is a focal length of the first single lens and f M is a focal length of the scanning lens system in the scanning direction.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |