EP0500134A2
Expired / Lapsed
EP
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Image forming apparatus
Assignee: Canon Inc
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Filing: 1992-02-21
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Granted: —
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Expires: 2012-02-21
Abstract
Abstract An image forming apparatus includes a generating section for generating an image signal representing an image of a predetermined density, an image forming section for forming an image on a recording medium on the basis of the image signal generated by the generating section, a measurement section for measuring the density of the image formed on the recording medium, and a control section for determining a condition for image formation on the basis of a measurement result from the measurement section. The control section selects a density of the image signal to be generated from the generating section according to an environment around the image forming section or an operation time of the image forming section.
Inventors
- 👤 Masanori C/O Canon Kabushiki Kaisha Muramatsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 14:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/50; G03G15/5033; G03G15/5041; H; H04; H04N; H04N1/00; H04N1/23; H04N1/29; H04N1/295; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042; G03G2215/00063; G03G2215/00071; G03G2215/00084
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
113 words
An image forming apparatus comprising: generating means for generating an image signal representing an image of a predetermined density; image forming means for forming an image on a recording medium on the basis of the image signal generated by said generating means; measurement means for measuring a density of the image formed on said recording medium; and control means for determining a condition for image formation on the basis of a measurement result from said measurement means, wherein said control means selects a density of the image signal to be generated from said generating means according to an environment around said image forming means or an operation time of said image forming means.
Claim 2
Dependent Claim
22 words
An apparatus according to claim 1, wherein said generating means generates image signals representing a plurality of images having different gray-scale levels.
Claim 3
Dependent Claim
53 words
An apparatus according to claim 1, wherein said image forming means comprises visualizing means of a plurality of colors for forming color images, and said control means selects the density of the image signal to be generated from said generating means according to a visualizing color of the visualizing means to be used.
Claim 4
Dependent Claim
29 words
An apparatus according to claim 1, wherein said control means forms a conversion table for converting a density on the basis of the measurement result from said measurement means.
Claim 5
Dependent Claim
50 words
An apparatus according to claim 1, wherein said control means comprises a memory for storing data representing a relationship between the environment around said image forming means or the operation time of said image forming means, and the density of the image signal to be generated from said generating means.
Claim 6
Dependent Claim
98 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; measurement means for measuring a density of the image formed on said recording medium; correction means for correcting a measurement result from said measurement means in a state wherein the image is formed on said recording medium on the basis of a measurement result from said measurement means in a state wherein no image is formed on said recording medium; and control means for determining a condition for image formation on the basis of the measurement result corrected by said correction means.
Claim 7
Dependent Claim
37 words
An apparatus according to claim 6, wherein said correction means obtains and stores a correction coefficient for correcting the measurement result of said measurement means in the state wherein the image is formed on said recording medium.
Claim 8
Dependent Claim
37 words
An apparatus according to claim 6, wherein said image forming means forms a toner image on said recording medium, and said correction means corrects a measurement error due to a stain with toner of said measurement means.
Claim 9
Dependent Claim
45 words
An apparatus according to claim 6, wherein said correction means receives the measurement result from said measurement means in the state wherein no image is formed on said recording medium before said image forming means forms an image for density measurement on said recording medium.
Claim 10
Dependent Claim
146 words
An image forming apparatus comprising: generating means for generating an image signal representing an image of a predetermined density; image forming means for forming an image on a rotating recording medium on the basis of the image signal generated from said generating means; measurement means for measuring a density of the image formed on said recording medium; first control means for controlling said generating means, said image forming means, and said measurement means to form an image of a predetermined density along the rotating direction of said recording medium for one rotation, and to sample and measure the density of the formed image for one rotation of said recording medium; and second control means for determining a condition for image formation on the basis of an average value of the densities sampled and measured by said measurement means under the control of said first control means.
Claim 11
Dependent Claim
29 words
An apparatus according to claim 10, wherein said second control means forms a conversion table for converting a density on the basis of the average value of the densities.
Claim 12
Dependent Claim
147 words
An image forming apparatus comprising: generating means for generating an image signal representing an image of a predetermined density; image forming means for forming an image on a rotating recording medium on the basis of the image signal generated from said generating means; measurement means for measuring a density of the image formed on said recording medium; first control means for controlling said generating means, said image forming means, and said measurement means to form images of a predetermined density on a plurality of 180°-opposing regions in the rotating direction of said recording medium, and to measure the densities of the plurality of formed images; and second control means for determining a condition for image formation on the basis of an average value of the densities of the images on the plurality of regions measured by said measurement means under the control of said first control means.
Claim 13
Dependent Claim
29 words
An apparatus according to claim 12, wherein said second control means forms a conversion table for converting a density on the basis of the average value of the densities.
Claim 14
Dependent Claim
118 words
An image forming apparatus comprising: generating means for generating image signals representing images having first and second density ranges; image forming means for forming images on a recording medium on the basis of the image signals generated by said generating means; measurement means for measuring densities of the images formed on said recording medium; control means for determining a condition for image formation on the basis of a measurement result from said measurement means, wherein said control means varies the condition for image formation to be determined depending on the measurement result of the density of the image having the first density range and the measurement result of the density of the image having the second density range.
Claim 15
Dependent Claim
24 words
An apparatus according to claim 14, wherein the first density range is a high-density range, and the second density range is a middle-density range.
Claim 16
Dependent Claim
36 words
An apparatus according to claim 15, wherein said control means forms a conversion table for converting a density on the basis of the measurement result of the density of the image having the second density range.
Claim 17
Dependent Claim
45 words
An apparatus according to claim 15, wherein said image forming means comprises charging means for charging said recording medium, and said control means controls said charging means on the basis of the measurement result of the density of the image having the first density range.
Claim 18
Dependent Claim
113 words
An image forming apparatus comprising: image forming means for forming a toner image on a photosensitive body; a sheet holding member, arranged to be in contact with said photosensitive body, for holding a transfer sheet so as to transfer the toner image formed on said photosensitive body onto the transfer sheet; a sensor for measuring a density of the toner image formed on said photosensitive body; control means for executing image stabilization control for determining a condition for image formation on the basis of an output from said sensor; and cleaning means for cleaning a surface of said sheet holding member, which holds the transfer sheet, during execution of the image stabilization control.
Claim 19
Dependent Claim
99 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; a sensor for measuring a density of the image formed on said recording medium; control means for executing image stabilization control for determining a condition for image formation on the basis of a measurement result from said sensor; and measurement means for measuring characteristics of said sensor or said recording medium prior to the image density measurement by said sensor, wherein said control means determines according to a measurement result from said measurement means whether or not the image stabilization control is executable.
Claim 20
Dependent Claim
61 words
An apparatus according to claim 19, wherein said control means permits an image forming operation, and inhibits execution of the image stabilization control when the measurement result from said measurement means indicates a first state, and inhibits both the image forming operation and execution of the image stabilization control when the measurement result from said measurement means indicates a second state.
Claim 21
Dependent Claim
43 words
An apparatus according to claim 20, wherein said control means permits an image forming operation on the basis of the condition for image formation determined by the latest image stabilization control when the measurement result from said measurement means indicates the first state.
Claim 22
Dependent Claim
18 words
An apparatus according to claim 19, wherein said measurement means measures a degree of stain of said sensor.
Claim 23
Dependent Claim
29 words
An apparatus according to claim 19, wherein said recording medium comprises a photosensitive body, and said measurement means measures charging characteristics of the entire surface of said photosensitive body.
Claim 24
Dependent Claim
145 words
An image forming apparatus comprising: generating means for generating an image signal representing an arbitrary density; image forming means for forming an image on a recording medium on the basis of the image signal generated by said generating means; measurement means for measuring a density of the image formed on said recording medium; and control means for determining a condition for image formation on the basis of a measurement result from said measurement means, wherein said control means causes said generating means to generate at least two types of image signals representing densities near a minimum density, calculates the measurement results of densities of images formed based on the two types of image signals to obtain a density of an image signal for minimizing the measurement result of said measurement means, and determines the condition for image formation on the basis of the obtained density.
Claim 25
Dependent Claim
24 words
An apparatus according to claim 24, wherein said recording medium comprises a photosensitive body, and said control means determines a potential for preventing fogging.
Claim 26
Dependent Claim
109 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; first measurement means for measuring an environmental condition of said image forming means; second measurement means for measuring a density of the image formed on said recording medium; and control means for controlling execution of image stabilization control for determining a condition for image formation on the basis of a measurement result from said second measurement means, wherein said control means executes the image stabilization control when a difference between the latest environmental condition measured by said first measurement means and the previously measured environmental condition is not less than a predetermined value.
Claim 27
Dependent Claim
122 words
An image forming apparatus comprising: image forming means for forming a color image on a recording medium, said image forming means comprising visualizing means of a plurality of colors; count means for counting the number of times of use of each of said plurality of visualizing means; measurement means for measuring a density of an image of each color formed on said recording medium; and control means for controlling execution of image stabilization control for determining a condition for image formation of each color on the basis of a measurement result from said measurement means, wherein said control means executes the image stabilization control of the color corresponding to a count value of said count means, which value exceeds a predetermined value.
Claim 28
Dependent Claim
25 words
An apparatus according to claim 27, wherein said count means resets the count value of the color for which the image stabilization control is executed.
References Cited (Backward Citations)
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