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US4700206A Expired / Lapsed US ⏱️ 0.0 years remaining

Image formation apparatus

Assignee: Canon Inc
•
Filing: 1987-01-08
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Granted: 1987-10-13
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Expires: 2007-01-08
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Abstract

Abstract An image formation apparatus has a photosensitive drum or photosensitive paper sheet for forming a dot image thereon, a printer head having an LED array, and LED drive ICs for selectively driving the LEDs. Dot width in the subscanning direction is properly controlled to form an excellent pseudo halftone image. A cylindrical lens or the like can be inserted between the LED array and the drum so as to prevent formation of black or white stripes in white or black image portions.

Inventors

  • 👤 Tadashi Yamakawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 08:02
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1247; B; B41; B41J; B41J2/00; B41J2/435; B41J2/447; B41J2/45; H; H04; H04N; H04N1/00; H04N1/024; H04N1/032; H04N1/036; H04N1/40; H04N1/40025; H04N1/40031; H10; H10H; H10H29/00; H10H29/10; H10H29/14

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 114 words
An image formation apparatus comprising; a photosensitive body; a light-emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction planes thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicualr to an array direction of the array of said diodes is shorter than that in the array direction; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 2
Dependent Claim 114 words
An image formation apparatus comprising; a photosensitive body; a light-emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction planes thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicualr to an array direction of the array of said diodes is shorter than that in the array direction; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 3
Dependent Claim 36 words
An apparatus according to claim 1, wherein said photosensitive body and said light emitting diode array are moved relative to each other in a direction substantially perpendicular to an array direction of said light-emitting diode array.
Claim 4
Dependent Claim 28 words
An apparatus according to claim 1, further comprising an imaging optical system for forming images of said light-emitting end faces of said light-emitting diodes onto said photosensitive body.
Claim 5
Dependent Claim 17 words
An apparatus according to claim 3, wherein said imaging optical system comprises a converging light transmitter array.
Claim 6
Dependent Claim 24 words
An apparatus according to claim 3, wherein said imaging optical system forms reduced images of said light emitting end faces on said photosensitive body.
Claim 7
Dependent Claim 35 words
An apparatus according to claim 1, wherein said control means includes a driving circuit for driving said light-emitting diodes and said driving circuit is fixed on a common substrate together with said light-emitting diode array.
Claim 8
Dependent Claim 139 words
An image formation apparatus comprising: a photosensitive body; a light emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes which emit light from end faces thereof perpendicular to p-n junction planes thereof and which are formed by being separated by grooves, a light absorbing member being coated to cover at least side surfaces of said grooves, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than that in the array direction; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 9
Dependent Claim 139 words
An image formation apparatus comprising: a photosensitive body; a light emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes which emit light from end faces thereof perpendicular to p-n junction planes thereof and which are formed by being separated by grooves, a light absorbing member being coated to cover at least side surfaces of said grooves, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than that in the array direction; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 10
Dependent Claim 41 words
An apparatus according to claim 7, wherein each of said light-emitting diodes of said light-emitting diode array is formed monolithically on said substrate, and said grooves are formed on said substrate to separate said p-n junction planes of said light-emitting diodes.
Claim 11
Dependent Claim 20 words
An apparatus according to claim 7, wherein said grooves of said light-emitting diodes are buried with the light absorbing member.
Claim 12
Dependent Claim 35 words
An apparatus according to claim 7, wherein said photosensitive body and said light-emitting diode array are moved relative to each other in a direction substantially perpendicular to an array direction of said light-emitting diode array.
Claim 13
Dependent Claim 28 words
An apparatus according to claim 7, further comprising an imaging optical system for forming images of said light-emitting end faces of said light-emitting diodes onto said photosensitive body.
Claim 14
Dependent Claim 33 words
An apparatus according to claim 7, further comprising a fiber plate for guiding light from said light-emitting diode array to said photosensitive body and consisting of a closely packed bundle of optical fiber.
Claim 15
Dependent Claim 174 words
An image formation apparatus comprising: a photosensitive body; a substrate; a light-emitting diode array for exposing said photosensitive body and fixed on said substrate, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction planes thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than that in the array direction; an imaging optical system for forming images of said light-emitting end faces of said light-emitting diodes in said diode array on said photosensitive body, said imaging optical system being fixed on a surface of said substrate which is parallel to a surface thereof mounting said light-emitting diode array through a height adjusting plate; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 16
Dependent Claim 174 words
An image formation apparatus comprising: a photosensitive body; a substrate; a light-emitting diode array for exposing said photosensitive body and fixed on said substrate, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction planes thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than that in the array direction; an imaging optical system for forming images of said light-emitting end faces of said light-emitting diodes in said diode array on said photosensitive body, said imaging optical system being fixed on a surface of said substrate which is parallel to a surface thereof mounting said light-emitting diode array through a height adjusting plate; and control means for selectively turning on said light-emitting diodes of said light-emitting diode array so as to form a dot image on said photosensitive body.
Claim 17
Dependent Claim 17 words
An apparatus according to claim 13, wherein said imaging optical system comprises a converging light transmitter array.
Claim 18
Dependent Claim 179 words
An image formation apparatus comprising: a photosensitive body; a light-emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction plane thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than in the array direction; an imaging optical system for forming images of said end faces of said diodes on said photosensitive body; optical means for reducing a modulation transfer function of the images formed by said imaging optical system in only the direction perpendicular to the array direction; means for moving said photosensitive body and said diode array relative to each other in the direction substantially perpendicular to the array direction of said diodes; and control means for selectively driving said diodes of said diode array and for forming a dot image on said photosensitive body.
Claim 19
Dependent Claim 179 words
An image formation apparatus comprising: a photosensitive body; a light-emitting diode array for exposing said photosensitive body, said array consisting of at least one array each consisting of a plurality of light-emitting diodes for emitting light from end faces thereof perpendicular to p-n junction plane thereof, said light emitting end face of each said diode having a shape such that a length of said end face in a direction perpendicular to an array direction of the array of said diodes is shorter than in the array direction; an imaging optical system for forming images of said end faces of said diodes on said photosensitive body; optical means for reducing a modulation transfer function of the images formed by said imaging optical system in only the direction perpendicular to the array direction; means for moving said photosensitive body and said diode array relative to each other in the direction substantially perpendicular to the array direction of said diodes; and control means for selectively driving said diodes of said diode array and for forming a dot image on said photosensitive body.
Claim 20
Dependent Claim 37 words
An apparatus according to claim 15, wherein said optical means comprises a cylindrical lens which is interposed between said diode array and said photosensitive body and a shape of which has a generatrix in the array direction.
Claim 21
Dependent Claim 17 words
An apparatus according to claim 15, wherein said imaging optical system comprises a converging light transmitter array.
Claim 22
Dependent Claim 27 words
An apparatus according to claim 15, wherein sid imaging optical system reduces the images of the light output surfaces and forms the images on said photosensitive body.
Claim 23
Dependent Claim 35 words
An apparatus according to claim 1, wherein said end faces of said light-emitting diodes are disposed near said photosensitive body and said photosensitive body is directly exposed to the light emitted from said end faces.
Claim 24
Dependent Claim 35 words
An apparatus according to claim 7, wherein said end faces of said light-emitting diodes are disposed near said photosensitive body and said photosensitive body is directly exposed to the light emitted from said end faces.
Claim 25
Dependent Claim 35 words
An apparatus according to claim 13, wherein said end faces of said light-emitting diodes are disposed near said photosensitive body and said photosensitive body is directly exposed to the light emitted from said end face.
Claim 26
Dependent Claim 35 words
An apparatus according to claim 13, wherein said photosensitive body and said light-emitting diode array are moved relative to each other in a direction substantially perpendicular to an array direction of said light-emitting diode array.

References Cited (Backward Citations)

US4467367A Cited
US4415913A Cited
US4455562A Cited
US4521790A Cited
US4525729A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-10-12 1991-04-13 1991-10-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-10-12 1995-04-13 1995-10-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-10-12 1999-04-13 1999-10-13 $7700.00 Window Closed / Lapsed

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