US5206755A
Expired / Lapsed
US
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Optical beam scanner
Assignee: Fujinon Corp
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Filing: 1991-10-03
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Granted: 1993-04-27
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Expires: 2011-10-03
Abstract
Abstract An optical beam scanner capable of correcting irregularities in pitch of beam scanning as caused by inclination or angular deviations of reflective deflection surfaces of a deflector, the scanner including a first image-forming optical system arranged to form an image of a light beam from a light source linearly on or in the vicinity of a reflective deflection surface of a deflector, and a second image-forming optical system arranged to form an image of the deflected light beam from the deflector on a scanning surface. The second image-forming optical system is constituted, successively from the side of the deflector, by a first singular lens element provided with at least one toric surface and having positive refractive power in a plane of transverse main scan direction, and a second singular lens element provided with either a spherical or cylindrical surface and having negative refractive power in the plane of the main scan direction.
Inventors
- 👤 Hiromitsu Yamakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:21
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/125; G02B27/00; G02B27/0025; G02B27/0031
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
314 words
An optical beam scanner of the type including a first image-forming optical system arranged to form an image of a light beam from a light source linearly on or in the vicinity of a reflective deflection surface of a deflector, and a second image-forming optical system arranged to form an image of the deflected light beam from said deflector on a scanning surface; characterized in that said second image-forming optical system comprises successively from the side of said deflector: a first singular lens element in the form of a positive meniscus, wherein in a first cross-section of the first singular lens element taken in a plane extending parallel to a main scan direction of said light beam, the first cross-section of the first singular lens element has a convex curve facing the scanning surface, and wherein in a second cross-section of the first singular lens element taken in a plane extending parallel to a subscan direction which is perpendicular to said main scan direction, the second cross-section of the first singular lens element has a convex curve facing said scanning surface, and wherein said first singular lens element has a toric surface at least one the side facing the deflector; a second singular lens element in the form of a negative meniscus, wherein in a first cross-section of the second singular lens element taken in a plane extending parallel to the main scan direction, the first cross-section of the second singular lens element has a convex curve facing said scanning surface and a concave curve facing said deflector, and wherein in a second cross-section of the second singular lens element taken in a plane ext ending parallel to said subscan direction, the second cross-section of the second singular lens element has either a convex curve or a straight line facing said scanning surface and either a concave curve or straight line facing said deflector.
Claim 2
Dependent Claim
314 words
An optical beam scanner of the type including a first image-forming optical system arranged to form an image of a light beam from a light source linearly on or in the vicinity of a reflective deflection surface of a deflector, and a second image-forming optical system arranged to form an image of the deflected light beam from said deflector on a scanning surface; characterized in that said second image-forming optical system comprises successively from the side of said deflector: a first singular lens element in the form of a positive meniscus, wherein in a first cross-section of the first singular lens element taken in a plane extending parallel to a main scan direction of said light beam, the first cross-section of the first singular lens element has a convex curve facing the scanning surface, and wherein in a second cross-section of the first singular lens element taken in a plane extending parallel to a subscan direction which is perpendicular to said main scan direction, the second cross-section of the first singular lens element has a convex curve facing said scanning surface, and wherein said first singular lens element has a toric surface at least one the side facing the deflector; a second singular lens element in the form of a negative meniscus, wherein in a first cross-section of the second singular lens element taken in a plane extending parallel to the main scan direction, the first cross-section of the second singular lens element has a convex curve facing said scanning surface and a concave curve facing said deflector, and wherein in a second cross-section of the second singular lens element taken in a plane ext ending parallel to said subscan direction, the second cross-section of the second singular lens element has either a convex curve or a straight line facing said scanning surface and either a concave curve or straight line facing said deflector.
Claim 3
Dependent Claim
64 words
An optical beam scanner as defined in claim 1, wherein said second image-forming optical system is arranged to satisfy the condition of 0.2<f.sub.v /f<0.5 where f is the overall focal length of said second optical system in the plane of said main scan direction and f v is the overall focal length of said second optical system in the plane of said subscan direction.
Claim 4
Dependent Claim
57 words
An optical beam scanner as defined in claim 1, wherein said first singular lens element is constituted by a cylindrical surface and a toric surface successively from the side of said deflector, and said second singular lens element is constituted by a first spherical surface and a second spherical surface successively from the side of said deflector.
Claim 5
Dependent Claim
55 words
An optical beam scanner as defined in claim 1, wherein said first singular lens element is constituted by a cylindrical surface and a toric surface successively from the side of said deflector, and said second singular lens element is constituted by a spherical surface and a cylindrical surface successively from the side of said deflector.
Claim 6
Dependent Claim
55 words
An optical beam scanner as defined in claim 1, wherein said first singular lens clement is constituted by a cylindrical surface and a toric surface successively from the side of said deflector, and said second singular lens element is constituted by a cylindrical surface and a spherical surface successively from the side of said deflector.
Claim 7
Dependent Claim
57 words
An optical beam scanner as defined in claim 1, wherein said first singular lens element is constituted by a cylindrical surface and a toric surface successively from the side of said deflector, and said second singular lens element is constituted by a first cylindrical surface and a second cylindrical surface successively from the side of said deflector.
Claim 8
Dependent Claim
59 words
An optical beam scanner as defined in claim 1, wherein said first singular lens element is constituted by a first toric surface and a second toric surface successively from the side of said deflector, and said second singular lens element is constituted by a first spherical surface and a second spherical surface successively from the side of said deflector.
Claim 9
Dependent Claim
57 words
An optical beam scanner as defined in claim 1, wherein said first singular lens element is constituted by a first toric surface and a second toric surface successively from the side of said deflector, and said second singular lens element is constituted by a cylindrical surface and a spherical surface successively from the side of said deflector.
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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) | 1996-04-26 | 1996-10-26 | 1997-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-26 | 2000-10-26 | 2001-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-26 | 2004-10-26 | 2005-04-27 | $7700.00 | Window Closed / Lapsed |