EP0744669A2
Expired / Lapsed
EP
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Wide area beam sensing method and apparatus for image registration calibration in a color printer
Assignee: Xerox Corp
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Filing: 1996-05-24
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Granted: —
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Expires: 2016-05-24
Abstract
Abstract Disclosed is a color printer including an image bearing member (10) having an imageable surface (11) for movement along a preselected path, at least a first imaging assembly (26,30) for forming sets of multiple black toner registration marks on different areas of the imageable surface, and for forming second sets of multiple non-black toner registration marks corresponding respectively to black marks in each set of the first sets of black marks so as to create a series of sets of multicolor registration marks. Each of the second sets is formed thus in accordance with a predetermined different condition of image misregistration relative to the corresponding first set of black toner marks. The color printer also includes a light source (142) for producing a wide area beam (172) to illuminate each set of the series of sets of multicolor marks, and a wide area beam (WAB) sensor (146) for measuring scattered or diffuse light (174) reflected from each set of the illuminated series of sets of multicolor marks, and for producing an actual light reflectance measurement value (Ca) from each such illuminated set. The printer further includes a comparing device for determining a degree of actual image misregistration by comparing each of the actual light reflectance measurement values with a stored predetermined registration offset value (Cp) corresponding to a predetermined condition of image misregistration for each illuminated set of multicolor marks. Mechanisms (137,138,139) are included in the printer for adjusting an imaging parameter of an imaging assembly responsively to the determined condition of actual misregistration so as to correct for the determined actual misregistration.
Inventors
- 👤 Jeffrey J. Folkins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5041; G03G15/01; G03G15/0142; G03G15/0147; G03G15/0152; G03G15/0163; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
363 words
A wide area beam (WAB) sensing method of calibrating for image registration in a color printer having an electronic control subsystem (28), the method comprising the steps of: (a) storing in the electronic control subsystem a first and at least a second predetermined registration offset value (Cp1,Cp2) corresponding to a first condition of image misregistration and to at least a second different condition of image misregistration, by the printer; (b) creating a first set (S1) of registration calibration marks (BM) of a first toner color on a first wide area and at least a second set of registration calibration marks (S2) of the first toner color on at least a second wide area of an image bearing member (10); (c) forming in accordance with the first condition of image misregistration, a first set of multi-color registration calibration marks (MM) by creating a set of registration marks (CM) of a different color toner relative to the first set of marks of the first toner color, wherein one of said first and said different color toners is black and the other non-black; (d) forming in accordance with the at least second condition of image misregistration, at least a second set (S2) of multicolor registration calibration marks (MM) by creating another set of registration marks (CM) of the different color toner relative to the at least second set of marks (BM) of the first toner color, wherein one of said first and said different color toners is black and the other non-black; (e) producing a first and at least a second actual light reflectance measurement value (Ca1) by illuminating the first and the at least second sets of multicolor registration calibration marks, and by sensing (124) the diffuse reflectance (174) from each set of multicolor registration calibration marks; (f) comparing the produced first (Ca1) and at least second (Ca2) actual light reflectance measurement values to the stored predetermined first (Cp1) and at least second (Cp2) registration offset values so as to determine an actual measure of image misregistration; and (g) adjusting an image forming parameter of the color printer responsively to the determined actual measure of image misregistration, thereby correcting for such determined actual image misregistration.
Claim 2
Dependent Claim
96 words
The method of claim 1, wherein step (b) comprises creating the first set of registration calibration marks (S1) on the first wide area, and four additional sets of registration calibration marks (S2-S5) on four additional wide areas of the image bearing member, and wherein the first set of registration calibration marks (S1) preferably include a plural number of spaced apart line marks (MM) in the first set, and the at least second set of registration calibration marks (S2) include a plural number of spaced apart line marks (MM) in each of the at least second sets.
Claim 3
Independent Claim
50 words
The method of claims 1 or 2, wherein steps (c) and (d) comprise creating sets of non-black toner marks (CM) that are each equal in dimension to the corresponding black toner mark (BM) only in the direction of image registration calibration in order to isolate misregistration in the calibration direction.
Claim 4
Dependent Claim
296 words
A color printer comprising: (a) an image bearing member (10) having a photoreceptive imageable surface (11) for movement along a preselected path; (b) first means (26,30) for forming on a different wide area of the imageable surface a plural number of first sets (S1-S5) of black toner registration calibration marks (BM), each said set including multiple spaced apart marks (BM); (c) second means (40a,100a) for forming a plural number of second sets (S1-S5) of non-black toner registration calibration marks (CM) corresponding to, and in accordance with predetermined built-in different conditions of image misregistration relative to, said plural number of first sets of black toner registration calibration marks, thereby creating a series of sets of multicolor registration calibration marks (MM); (d) a light source (142) for producing a wide area beam (172) for illuminating each set of said plural number of sets of multicolor marks; (e)a wide area beam (WAB) sensor (124) for producing an actual light reflectance measurement value (Cal-Ca5) from each said illuminated set of multicolor marks by measuring scattered light (174) from each said illuminated set (S1-S5) of said plural number of sets of multicolor marks (MM); (f) a comparing device (28) for determining a degree of actual misregistration between said first sets of black toner marks and said second sets of non-black toner marks of each illuminated set of multicolor marks corresponding to each predetermined condition of image misregistration by comparing said actual light reflectance measurement value (Ca1-Ca5) from said each illuminated set (S1-S5) with the stored predetermined registration offset value (Cp1-Cp3) for said set; and (g) mechanisms (137,138,139) for adjusting an image forming parameter of at least one of said first and said second means responsively to said determined degree of actual misregistration so as to correct for said determined actual misregistration.
Claim 5
Dependent Claim
83 words
The color printer of claim 4, wherein said wide area beam sensor (124) includes; (a) a collimating lens (156); (b) a collecting lens (154) for collecting reflected light rays (172); and (c) a photosensor array (146) for receiving reflected light rays being transmitted through said collecting lens to generate (i) a total signal proportional to a total flux of said light rays being transmitted through said collecting lens, and (b) a diffuse signal proportional to a diffuse component (174) of the total flux.
Claim 6
Dependent Claim
63 words
The color printer of claims 4 or 5, wherein said wide area beam sensor is mounted within the printer at a diffuse angle relative to said light source and preferably at a location downstream of imager assemblies (26,40a-40c) for forming in proper registration different color component images so as to enable image registration calibration, misregistration correction, and image formation in a single pass.
Claim 7
Dependent Claim
75 words
The color printer of any one of claims 4 to 6, including a controller (28) for controlling said first and said second means to selectively (a) form series of sets of registration calibration marks comprising lines running orthogonally to the process direction for calibrating process direction registration, as well as (b) form series of sets of registration calibration marks comprising lines running orthogonally to the cross-process direction for calibrating cross-process direction registration in the printer.
Claim 8
Dependent Claim
45 words
The color printer of any one of claims 4 to 7, wherein said light source (142) comprises an erase lamp also usable for erasing charges from portions of the photoreceptive surface, and wherein said light source is preferably built into said wide area beam sensor.
Claim 9
Dependent Claim
34 words
The color printer of any one of claims 4 to 8, wherein said image bearing member (10) is translucent and said light source (142) is mounted to the backside of the image bearing member.
Claim 10
Dependent Claim
36 words
The color printer of any one of claims 4 to 9, wherein said predetermined different conditions of image misregistration include -2U, -1U, 0U, +1U, and +2U where 'U' is a unit of measure of image misregistration.
References Cited (Backward Citations)
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