Patent EP0195655A2 successfully refreshed from Google Patents.
EP0195655A2
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EP
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Automatic setup of electrophotographic printing machines
Assignee: Xerox Corp
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Filing: 1986-03-18
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Granted: —
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Expires: 2006-03-18
Abstract
Abstract An automated process and apparatus for establishing the basic xerographic operating parameters for an electophotographic printing machine. The document scanning means (42, 43, 44, 45) is used in a setup mode to generate test patches (100, 102, 104, 106) of varying density on the machine photoreceptor (10). The levels are measured and compared to pre-set values stored in a digital controller memory until convergence is obtained along three separate points on the photo-induced discharge curve (PIDC) (see Figure 2). The controller (31) adjusts the system parameters of charge circuit, developer bias and system exposure in an iterative process and corresponding to the PIDC for the particular machine.
Inventors
- 👤 James Patrick Russell
- 👤 Ralph Gordon Faull
- 👤 Wayne Alan Buchar
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5041; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
283 words
Apparatus for optimizing the operation of an electrophotographic printing machine having a corona device for applying a charge to the machine photoreceptor, a scan-illumination optical system for illuminating a document to be copied on a platen surface and for projecting an image of the document along an optical path onto the photoreceptor to form a latent image thereof, a developer unit for applying toner to the belt surface, said apparatus comprising, a digital controller, memory means within said controller, having stored therein a digital representation of the photo-induced discharge curve (PIDC) for the machine photoreceptor, optical test patch generation means comprising part of said scan-illumination system, said patch generation means adapted to form at least a dark development V DDP patch, a second, full illumination V SG patch and a third intermediate development patch on said photoreceptor, a voltmeter for sensing photoreceptor voltage at said test patch areas and for sending representative signals to said memory means, arid first logic means within said controller for analyzing the voltmeter input signals representing the values V DDP and V BG levels, comparing the difference (constant contrast voltage V c ), between these signals and a preset optimum value of Vc stored within the memory means and selectively regulating the corona device and the developer unit in an iterative process until convergence is obtained between said difference and said preset value, said logic means being adapted to analyze the voltmeter input signals representing said intermediate development patch, comparing said signal with a preset optimum value stored within the memory means and selectively regulating the illumination output level of said scan-illumination optical system in an iterative process until convergence is obtained between said measured and stored values.
Claim 2
Dependent Claim
283 words
Apparatus for optimizing the operation of an electrophotographic printing machine having a corona device for applying a charge to the machine photoreceptor, a scan-illumination optical system for illuminating a document to be copied on a platen surface and for projecting an image of the document along an optical path onto the photoreceptor to form a latent image thereof, a developer unit for applying toner to the belt surface, said apparatus comprising, a digital controller, memory means within said controller, having stored therein a digital representation of the photo-induced discharge curve (PIDC) for the machine photoreceptor, optical test patch generation means comprising part of said scan-illumination system, said patch generation means adapted to form at least a dark development V DDP patch, a second, full illumination V SG patch and a third intermediate development patch on said photoreceptor, a voltmeter for sensing photoreceptor voltage at said test patch areas and for sending representative signals to said memory means, arid first logic means within said controller for analyzing the voltmeter input signals representing the values V DDP and V BG levels, comparing the difference (constant contrast voltage V c ), between these signals and a preset optimum value of Vc stored within the memory means and selectively regulating the corona device and the developer unit in an iterative process until convergence is obtained between said difference and said preset value, said logic means being adapted to analyze the voltmeter input signals representing said intermediate development patch, comparing said signal with a preset optimum value stored within the memory means and selectively regulating the illumination output level of said scan-illumination optical system in an iterative process until convergence is obtained between said measured and stored values.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 further including discrete patch generator erase means positioned adjacent the photoreceptor and adapted to selectively erase said development patches during said iterative process.
Claim 4
Dependent Claim
91 words
The apparatus of claim 1 or claim 2 further including a densitometer positioned adjacent the photoreceptor downstream from the development station, and wherein said optical test patch generation means is adapted to produce a second intermediate development patch on said photoreceptor, said logic means further adapted to analyze the voltmeter input representing said second intermediate level and the V DDP level, comparing the difference between these signals, and, if a difference is detected, selectively regulating the discrete patch generator output in an iterative process until the two measured values are equal.
Claim 5
Dependent Claim
96 words
The apparatus of claim 1 wherein said optical test patch generation means includes a scan carriage comprising an elongated illumination assembly and a scan mirror, an opaque occluder which can be positioned in the optical path before the photoreceptor, said platen surface having a first intermediate density target strip affixed to the bottom surface at a test patch generation position and a second intermediate density target strip affixed to the bottom surface at a further position, said digital controller adapted to vary the output of said illuminator assembly at each of the test patch generation positions.
Claim 6
Dependent Claim
159 words
A process of automatically adjusting the basic xerographic parameters of an electrophotographic printing machine evaluating charging circuit, lc, developer bias V BIAS and system exposure E o , comprising the steps of: a) driving the machine document scanning optics in a test patch generation mode to lay down a plurality of test patches of different densities on the machine photoreceptor, including a first test patch representing dark decay potential V DDP , a second patch representing background voltage level V BG and a third patch representing an intermediate voltage level Vo. 3 o, b) measuring the voltage levels at said test patches and generating signals indicative thereof, c) analyzing said voltage level signals and comparing preset values representative of values lying along the PIDC curve of the particular photoreceptor, d) adjusting the machine parameters Ic , V BIAS , and Eo until these comparison values find convergence with these points on the PIDC curve established for the machine photoreceptor.
Claim 7
Dependent Claim
159 words
A process of automatically adjusting the basic xerographic parameters of an electrophotographic printing machine evaluating charging circuit, lc, developer bias V BIAS and system exposure E o , comprising the steps of: a) driving the machine document scanning optics in a test patch generation mode to lay down a plurality of test patches of different densities on the machine photoreceptor, including a first test patch representing dark decay potential V DDP , a second patch representing background voltage level V BG and a third patch representing an intermediate voltage level Vo. 3 o, b) measuring the voltage levels at said test patches and generating signals indicative thereof, c) analyzing said voltage level signals and comparing preset values representative of values lying along the PIDC curve of the particular photoreceptor, d) adjusting the machine parameters Ic , V BIAS , and Eo until these comparison values find convergence with these points on the PIDC curve established for the machine photoreceptor.
Claim 8
Dependent Claim
19 words
The process of claim 4 including the step of selectively erasing said test patches using a discrete light source5
Claim 9
Dependent Claim
22 words
7 . The process of claim 6 including the additonal step of calibrating said discrete light source to the final machine parameters.
Claim 10
Dependent Claim
219 words
An electrophotographic printing machine wherein a document on a support platen is scanned and an image thereof is projected onto a photoreceptor surface, having an optical illumination and scanning system adapted to operate in a first and second mode of operation, said system comprising: means for moving an illumination and scan assembly mounted beneath said platen in a first, document copying, mode from a start of scan to an end of scan to the start of scan position whereby a latent image of the document is formed on the photoreceptor surface, at least one density target strip affixed to the bottom surface of the platen at a location outside the end of scan position, said moving means adapted to move said illumination and scan assembly, in a second, test, mode of operation, to a first position outside the start of scan position, said motion occurring coincident with the positioning of an opaque occluder in the optical path to form a dark decay test patch at the photoreceptor surface, said moving means further adapted to move said illumination and scan assembly from said first position to a second position beneath said target strip, and means for selectively and sequentially altering the illumination level directed to said target strip to thereby form test patches of varying density at the photoreceptor surface.
Claim 11
Dependent Claim
219 words
An electrophotographic printing machine wherein a document on a support platen is scanned and an image thereof is projected onto a photoreceptor surface, having an optical illumination and scanning system adapted to operate in a first and second mode of operation, said system comprising: means for moving an illumination and scan assembly mounted beneath said platen in a first, document copying, mode from a start of scan to an end of scan to the start of scan position whereby a latent image of the document is formed on the photoreceptor surface, at least one density target strip affixed to the bottom surface of the platen at a location outside the end of scan position, said moving means adapted to move said illumination and scan assembly, in a second, test, mode of operation, to a first position outside the start of scan position, said motion occurring coincident with the positioning of an opaque occluder in the optical path to form a dark decay test patch at the photoreceptor surface, said moving means further adapted to move said illumination and scan assembly from said first position to a second position beneath said target strip, and means for selectively and sequentially altering the illumination level directed to said target strip to thereby form test patches of varying density at the photoreceptor surface.
Claim 12
Dependent Claim
19 words
The electrophotographic printing machine of claim 8 wherein the test patches are formed along the centerline of the photoreceptor.
References Cited (Backward Citations)
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