Patent EP0183165A2 successfully refreshed from Google Patents.
EP0183165A2
Expired / Lapsed
EP
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High resolution laser printer
Assignee: ECRM Trust
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Filing: 1985-11-18
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Granted: —
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Expires: 2005-11-18
Abstract
Abstract A high resolution laser printer utilizes a first cylindrical lens to focus a laser beam in the sagittal direction prior to the facets of a rotating polygon. The light reflected from the polygon is focused in the horizontal direction at the photoconductor drum of an electrophotographic process by a scan lens assembly. Following the scan lens assembly, there is a second cylindrical lens which also focuses the laser beam in the horizontal direction at the photoconductor. The first and second cylindrical lenses are positioned to eliminate errors in the facets of the polygon. Scan speed errors are corrected by storing correction information in a memory and using this information to vary the rate at which the laser is modulated with data.
Inventors
- 👤 David R. Spencer
- 👤 Amnon Goldstein
- 👤 David Grey
- 👤 Theodore G. Balchunas
- 👤 Arthur B. Kaplan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:04
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1204; G06K15/1219
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
A high resolution laser printer comprising: photosensitive medium; means for generating a modulated beam of laser light; at least one moving mirror surface located in the path of said light beam and reflecting the beam such that it sweeps across said medium; an optical collimator means located between said laser and said mirror surface for forming the modulated laser light into a substantially collimated beam; first cylindrical lens means located between said collimator means and said mirror surface for focusing the light output of said collimator means in the sagittal or cross-scan direction at a position just prior to said mirror surface; a scan lens assembly positioned between said mirror surface and said medium for focusing the reflected light in the horizontal or scan direction such that it is in focus along a substantially straight line across said medium; and a second cylindrical lens positioned between said scan lens assembly and said medium for focusing said beam in the sagittal direction along said medium.
Claim 2
Dependent Claim
164 words
A high resolution laser printer comprising: photosensitive medium; means for generating a modulated beam of laser light; at least one moving mirror surface located in the path of said light beam and reflecting the beam such that it sweeps across said medium; an optical collimator means located between said laser and said mirror surface for forming the modulated laser light into a substantially collimated beam; first cylindrical lens means located between said collimator means and said mirror surface for focusing the light output of said collimator means in the sagittal or cross-scan direction at a position just prior to said mirror surface; a scan lens assembly positioned between said mirror surface and said medium for focusing the reflected light in the horizontal or scan direction such that it is in focus along a substantially straight line across said medium; and a second cylindrical lens positioned between said scan lens assembly and said medium for focusing said beam in the sagittal direction along said medium.
Claim 3
Dependent Claim
24 words
A laser printer system as claimed in claim 1 wherein the moving mirror surface is formed as a facet of a multi-faceted rotating polygon.
Claim 4
Dependent Claim
33 words
A laser, printer system as claimed in claim 1 wherein said collimator comprises in series a spherical concave- convex lens, a doublet including double concave and double convex lenses, and a plano-convex lens.
Claim 5
Dependent Claim
30 words
A laser printer system convex lenses, and a plano-convex said scan lens assembly comprises in series two spherical concave-convex lenses and a doublet including double concave and double convex lenses.
Claim 6
Dependent Claim
30 words
A laser printer system convex lenses, and a plano-convex said scan lens assembly comprises in series two spherical concave-convex lenses and a doublet including double concave and double convex lenses.
Claim 7
Dependent Claim
132 words
A laser printer system comprising: means for generating an information modulated laser beam; optical means for causing said laser beam to come into focus at, and to sweep across, a recording medium sensitive to said light; a photosensitive means for detecting the start of sweep of said light beam across said recording medium; and correcting means for varying the rate of modulation of said laser beam as it sweeps across said medium to compensate for variations in the velocity of said beam, said correcting means including memory means for storing correction data sufficient to create a continuously varying correction signal opposite to the velocity variations and means for using the correction data stored in the memory to vary the rate at which modulation information is applied to said laser beam generating means.
Claim 8
Dependent Claim
132 words
A laser printer system comprising: means for generating an information modulated laser beam; optical means for causing said laser beam to come into focus at, and to sweep across, a recording medium sensitive to said light; a photosensitive means for detecting the start of sweep of said light beam across said recording medium; and correcting means for varying the rate of modulation of said laser beam as it sweeps across said medium to compensate for variations in the velocity of said beam, said correcting means including memory means for storing correction data sufficient to create a continuously varying correction signal opposite to the velocity variations and means for using the correction data stored in the memory to vary the rate at which modulation information is applied to said laser beam generating means.
Claim 9
Dependent Claim
64 words
A laser printer system as claimed in claim 5 wherein the medium is a photoconductor and further including means for creating an electrostatic charge image on said photoconductor, developing said image and transferring said developed image to plain paper, said means for creating an electrostatic image including at least one corona generator powered by a constant current power supply sensing only its own output.
References Cited (Backward Citations)
No citation records indexed.
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