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EP0378149A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Achromatic-type laser scanning optical system

Assignee: Canon Inc
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Filing: 1990-01-08
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Granted: —
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Expires: 2010-01-08
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Abstract

Abstract An achromatic-type scanning optical arrangement includes a laser source, a first optical system for converging a beam of light emanating from the laser source, a deflecting device for deflecting the beam of light converged by the first optical system and a second optical system for focusing the beam of light deflected by the deflecting device onto a predetermined position. The entire optical system including the first optical system (12) and the second optical system is corrected for chromatic aberration, as a whole, to eliminate the adverse influence of wavelength variations in the laser source upon variations in the focus position of the aforesaid beam of light.

Inventors

  • 👤 Jun Makino
  • 👤 Jun Koide

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 21:33
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B27/00; G02B27/0025; G02B27/0031

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 102 words
A scanning optical apparatus comprising: a laser source; an optical system comprising a first and a second optical system; said first optical system for converging a beam of light emanating from said laser source; deflecting means for deflecting the beam of light converged by said first optical system; said second optical system for focusing the beam of light deflected by said deflecting means onto a predetermined position; and means for correcting chromatic aberration of said optical system, as a whole, to eliminate adverse influence of wavelength variations in said laser source upon variations in the focus position of the beam of light.
Claim 2
Dependent Claim 102 words
A scanning optical apparatus comprising: a laser source; an optical system comprising a first and a second optical system; said first optical system for converging a beam of light emanating from said laser source; deflecting means for deflecting the beam of light converged by said first optical system; said second optical system for focusing the beam of light deflected by said deflecting means onto a predetermined position; and means for correcting chromatic aberration of said optical system, as a whole, to eliminate adverse influence of wavelength variations in said laser source upon variations in the focus position of the beam of light.
Claim 3
Dependent Claim 27 words
A scanning optical apparatus according to claim 1, wherein said first optical system has chromatic aberration opposite in characteristic to chromatic aberration of said second optical system.
Claim 4
Dependent Claim 20 words
A scanning optical apparatus according to claim 1, further comprising means for overcorrecting chromatic aberration of said first optical system.
Claim 5
Dependent Claim 18 words
A scanning optical apparatus according to claim 1, wherein said first optical system comprises a collimator lens arrangement.
Claim 6
Dependent Claim 18 words
A scanning optical apparatus according to claim 1, wherein said first optical system comprises a cylindrical lens arrangement.
Claim 7
Dependent Claim 18 words
A scanning optical apparatus according to claim 1, wherein said second optical system has an fϑ lens arrangement.
Claim 8
Dependent Claim 42 words
A collimating optical apparatus comprising: a laser source; and an optical system for collimating a beam of light emanating from said laser source, said optical system comprising a cemented lens arrangement, said cemented lens arrangement for travelling along an optical axis thereof.
Claim 9
Dependent Claim 42 words
A collimating optical apparatus comprising: a laser source; and an optical system for collimating a beam of light emanating from said laser source, said optical system comprising a cemented lens arrangement, said cemented lens arrangement for travelling along an optical axis thereof.
Claim 10
Dependent Claim 85 words
A scanning optical apparatus comprising: a laser source; a collimator lens assembly comprising a plurality of lens elements for collimating a beam of light emanating from said laser source; a cylindrical lens assembly comprising a plurality of lens elements for converging the beam of light collimated by said collimator lens assembly; deflecting means for deflecting the beam of light converged by said cylindrical lens assembly; and a second optical system for focusing the beam of light deflected by said deflecting means onto a predetermined position.
Claim 11
Dependent Claim 85 words
A scanning optical apparatus comprising: a laser source; a collimator lens assembly comprising a plurality of lens elements for collimating a beam of light emanating from said laser source; a cylindrical lens assembly comprising a plurality of lens elements for converging the beam of light collimated by said collimator lens assembly; deflecting means for deflecting the beam of light converged by said cylindrical lens assembly; and a second optical system for focusing the beam of light deflected by said deflecting means onto a predetermined position.
Claim 12
Dependent Claim 135 words
A scanning optical apparatus comprising: a light source; deflecting means for deflecting a beam of light emanating from said light source; and a scanning lens arrangement having an f·ϑ characteristic for focusing the beam of light deflected by said deflecting means on a predetermined position, said scanning lens arrangement receiving an incident beam of parallel light in a main-scan plane; wherein where f: focal length of said scanning lens arrangement in said main-scan plane, δλ: width of a wavelength variation, λc: wavelength of a C line, λ F : wavelength of an F line, φi: reciprocal of the focal length of each lens element which constitute said scanning lens arrangement, νdi: Abbe number of each lens element which constitute said scanning lens arrangement, α: scanning angle, and d: spot diameter measured in the main-scan direction.
Claim 13
Dependent Claim 135 words
A scanning optical apparatus comprising: a light source; deflecting means for deflecting a beam of light emanating from said light source; and a scanning lens arrangement having an f·ϑ characteristic for focusing the beam of light deflected by said deflecting means on a predetermined position, said scanning lens arrangement receiving an incident beam of parallel light in a main-scan plane; wherein where f: focal length of said scanning lens arrangement in said main-scan plane, δλ: width of a wavelength variation, λc: wavelength of a C line, λ F : wavelength of an F line, φi: reciprocal of the focal length of each lens element which constitute said scanning lens arrangement, νdi: Abbe number of each lens element which constitute said scanning lens arrangement, α: scanning angle, and d: spot diameter measured in the main-scan direction.

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