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US4070089A Expired / Lapsed US ⏱️ 0.0 years remaining

Two dimensional laser scanner with movable cylinder lens

Assignee: Xerox Corp
•
Filing: 1976-07-01
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Granted: 1978-01-24
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Expires: 1996-07-01
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Abstract

Abstract An intensity modulated laser beam is directed to a rotating scanner having a plurality of facets which scans the beam across the surface of a movable mirror in a first scan direction. The mirror is movable in a manner whereby the beam is deflected in a second scan direction. The light reflected from the movable mirror is directed through a focusing lens onto a movable cylinder lens located adjacent the platen which is movable in a direction corresponding to the second scan direction, thereby providing two-dimensional scanning of a document. In one embodiment, the movable mirror and the movable cylinder lens are driven by a single motor and are coupled together in the manner whereby the movement thereof is mechanically interlocked thereby providing perfect tracking of the scanned laser beam within the clear aperture of the cylinder lens. In a second embodiment, the movable mirror and the movable cylinder lens may be independently driven and interlocked electronically. By proper focusing of the laser beam such that the sagittal focal plane is located between the movable mirror and the rotating scanner, a compromise of sagittal motion compensation due to pyramidal errors of the scanner facets and sagittal angular variations of the movable mirror is achieved. The rotating scanner may also be tilted in a predetermined manner whereby unsymmetrical scan linearity in the first scan direction upon each side of the scan line center is minimized.

Inventors

  • 👤 David A. Grafton

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 20:31
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/113; G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/123

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 200 words
A flying spot scanning system comprising: means for generating a beam of coherent light, a rotatable mirror, a rotatable polygon scanner located between said light generating means and said rotatable mirror and in the path of said beam for scanning said beam onto said rotatable mirror, a stationary mirror positioned adjacent said rotatable mirror, lens means interposed between said rotatable mirror and said stationary mirror whereby the beam reflected from said rotatable mirror is directed to said stationary mirror through said lens means, a generally planar document support member, a movable cylinder lens movable in a first direction and positioned adjacent said document support member, said stationary mirror reflecting said beam to said document support member through said cylinder lens, said cylinder lens extending in a direction whereby the beam will be scanned across a document placed on said document support member in a second direction and orthogonal to said first direction, and means for controlling the rotation of said rotatable mirror and the movement of said cylinder lens such that the light reflected from said rotatable mirror is always incident on said cylinder lens as the cylinder lens moves in said first direction whereby said document is completely scanned.
Claim 2
Dependent Claim 200 words
A flying spot scanning system comprising: means for generating a beam of coherent light, a rotatable mirror, a rotatable polygon scanner located between said light generating means and said rotatable mirror and in the path of said beam for scanning said beam onto said rotatable mirror, a stationary mirror positioned adjacent said rotatable mirror, lens means interposed between said rotatable mirror and said stationary mirror whereby the beam reflected from said rotatable mirror is directed to said stationary mirror through said lens means, a generally planar document support member, a movable cylinder lens movable in a first direction and positioned adjacent said document support member, said stationary mirror reflecting said beam to said document support member through said cylinder lens, said cylinder lens extending in a direction whereby the beam will be scanned across a document placed on said document support member in a second direction and orthogonal to said first direction, and means for controlling the rotation of said rotatable mirror and the movement of said cylinder lens such that the light reflected from said rotatable mirror is always incident on said cylinder lens as the cylinder lens moves in said first direction whereby said document is completely scanned.
Claim 3
Dependent Claim 15 words
The scanning system as defined in claim 1 wherein said generating means comprises laser means.
Claim 4
Dependent Claim 50 words
The scanning system as defined in claim 2 wherein said laser means comprises first and second lasers, said first laser generating an output beam having a first wavelenght and said second laser means generating an output beam having a second wavelength, said first wavelength being different than said second wavelength.
Claim 5
Dependent Claim 33 words
The scanning system as defined in claim 1 wherein said controlling means comprises a motor which drives a drive member, said drive member being coupled to said rotatable mirror and said cylinder lens.
Claim 6
Dependent Claim 16 words
The scanning system as defined in claim 4 wherein said drive member comprises a cable arrangement.
Claim 7
Dependent Claim 48 words
The scanning system as defined in claim 1 wherein said controlling means comprises an amplifier the output of which is coupled to first and second drive means, said first drive means being coupled to said rotatable mirror and said second drive means being coupled to said cylinder lens.
Claim 8
Dependent Claim 43 words
The scanning system as defined in claim 1 further including a lens assembly positioned between said light generating means and said rotatable mirror and in the path of said beam, said lens assembly focusing the beam incident thereon at two different focal lines.
Claim 9
Dependent Claim 25 words
The scanning system as defined in claim 7 wherein one of said focal lines is located between said rotating polygon scanner and said rotatable mirror.

References Cited (Backward Citations)

US3719780A Cited
US3701999A Cited
US3877777A Cited
US3946150A Cited
US4002829A Cited
US3944323A Cited
US3973825A Cited
US3970359A Cited
US3966319A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-01-23 1981-07-25 1982-01-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-01-23 1985-07-25 1986-01-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-01-23 1989-07-25 1990-01-24 $7700.00 Window Closed / Lapsed

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