Scanning optical system
First Claim
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1. A scanning optical system, comprising:
- a light source;
a deflector that deflects a beam emitted from said light source; and
a scanning lens that converges said beam deflected by said deflector onto a surface to be scanned, said scanning lens having a positive power and a plurality of refraction lens elements, a diffraction lens structure being formed on at least one surface of one of said plurality of refraction lens elements, said diffraction lens structure compensating a lateral chromatic aberration caused by said plurality of refraction lens element, said scanning lens includes at least one toric surface.
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Abstract
Disclosed is a scanning optical system, which is provided with a light source, a deflector, which deflects a beam emitted from said light source, and a scanning lens for converging the beam deflected by said deflector onto a surface to be scanned. The scanning lens has a positive power as a whole, and includes a plurality of refraction lens elements. Further, a diffraction lens structure is formed on at least one surface of one of the plurality of lens elements. Combination of the refraction lens elements and the diffraction lens structure compensates a lateral chromatic aberration caused by the refraction lens elements.
33 Citations
12 Claims
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1. A scanning optical system, comprising:
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a light source; a deflector that deflects a beam emitted from said light source; and a scanning lens that converges said beam deflected by said deflector onto a surface to be scanned, said scanning lens having a positive power and a plurality of refraction lens elements, a diffraction lens structure being formed on at least one surface of one of said plurality of refraction lens elements, said diffraction lens structure compensating a lateral chromatic aberration caused by said plurality of refraction lens element, said scanning lens includes at least one toric surface. - View Dependent Claims (2, 3, 4, 5, 6)
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- 7. A scanning lens having a positive power, said scanning lens having a plurality of refraction lens elements, a diffraction lens structure being formed on at least one surface of said plurality of refraction lens elements, said diffraction lens structure compensating a lateral chromatic aberration within a range of approximately minus 15 nm to approximately plus 15 nm with respect to a design wavelength that is caused by said plurality of refraction lens elements, said scanning lens includes at least one toric surface.
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9. A scanning optical system, comprising:
a scanning lens that has a positive power and a plurality of refraction lens elements, a diffraction lens structure being formed on at least one surface of one of said plurality of refraction lens elements, said diffraction lens structure compensating a lateral chromatic aberration caused by said plurality of refraction lens elements, said scanning lens having at least one toric surface. - View Dependent Claims (10, 11, 12)
Specification