US5376956A
Expired / Lapsed
US
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Image forming apparatus
Assignee: Canon Inc
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Filing: 1992-12-30
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Granted: 1994-12-27
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Expires: 2012-12-30
Abstract
Abstract An image forming apparatus forms a predetermined test image, detects a spatial frequency characteristic of the test image, and determines an optimum image forming condition on the basis of the detected spatial frequency characteristic.
Inventors
- 👤 Yoshinori Nagao
- 👤 Koji Amemiya
- 👤 Masami Izumizaki
- 👤 Nobuatsu Sasanuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:32
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/23; H04N1/29; H04N1/295; B; B41; B41J; B41J2/00; B41J2/525; G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/0131; G03G15/50; G03G15/5033; G03G15/5041; G03G15/5054; G03G15/5058; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042; G03G2215/00059; G03G2215/01; G03G2215/0167; G03G2215/0174; G03G2215/0177
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
An image forming method comprising the steps of: a) forming a test image having a striped pattern on a recording medium by image forming means; b) reading the test image formed on said recording medium by a line sensor which is arranged opposite to said recording medium, said line sensor consisting of a plurality of photosensitive elements; c) detecting a maximum value and a minimum value of output from each photosensitive element of said line sensor and calculating the detected maximum value and minimum value; and d) determining an operating condition of said image forming means so as to obtain an optimum calculation result of said detecting means.
Claim 2
Dependent Claim
108 words
An image forming method comprising the steps of: a) forming a test image having a striped pattern on a recording medium by image forming means; b) reading the test image formed on said recording medium by a line sensor which is arranged opposite to said recording medium, said line sensor consisting of a plurality of photosensitive elements; c) detecting a maximum value and a minimum value of output from each photosensitive element of said line sensor and calculating the detected maximum value and minimum value; and d) determining an operating condition of said image forming means so as to obtain an optimum calculation result of said detecting means.
Claim 3
Dependent Claim
31 words
An image forming method according to claim 1, wherein the determining step repeats the forming step, reading step, and detecting step under a different operating condition of said image forming means.
Claim 4
Dependent Claim
24 words
An image forming method according to claim 1, wherein the operating condition of said image forming means is determined for every image forming color.
Claim 5
Dependent Claim
104 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; a line sensor, being arranged opposite to said recording medium, for reading the image formed on said recording medium, said line sensor including a plurality of reading elements; and control means for making said image forming means form a test image having a striped pattern on said recording medium, for making said line sensor read the formed test image, and for determining an optimum operating condition of said image forming means on the basis of a maximum value and a minimum value of output from said line sensor.
Claim 6
Dependent Claim
104 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; a line sensor, being arranged opposite to said recording medium, for reading the image formed on said recording medium, said line sensor including a plurality of reading elements; and control means for making said image forming means form a test image having a striped pattern on said recording medium, for making said line sensor read the formed test image, and for determining an optimum operating condition of said image forming means on the basis of a maximum value and a minimum value of output from said line sensor.
Claim 7
Dependent Claim
58 words
An image forming apparatus according to claim 4, wherein said control means makes said image forming means form the test image repeatedly under a different operating condition and determines the optimum operating condition on the basis of a calculation result of the maximum value and minimum value output from said line sensor after each test image is read.
Claim 8
Dependent Claim
37 words
An image forming apparatus according to claim 4, wherein said image forming means can form an image having a plurality of colors, and said control means determines the optimum operating condition for every color in the image.
Claim 9
Dependent Claim
48 words
An image forming apparatus according to claim 4, wherein said image forming means comprises latent image forming means for forming a latent image on the recording medium and developing means for developing the latent image, and wherein said control means controls a developing bias of said developing means.
Claim 10
Dependent Claim
21 words
An image forming apparatus according to claim 7, wherein said control means controls an alternating-current developing bias of said developing means.
Claim 11
Dependent Claim
110 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; a line sensor, being arranged opposite to said recording medium, for reading the image formed on said recording medium, said line sensor including a plurality of reading elements; and control means for making said image forming means form a test image having a striped pattern on said recording medium, for making said line sensor read the formed test image, for calculating a modulation transfer function on the basis of output from said line sensor, and for determining an operating condition of said image forming means so that the calculated modulation transfer function is optimum.
Claim 12
Dependent Claim
110 words
An image forming apparatus comprising: image forming means for forming an image on a recording medium; a line sensor, being arranged opposite to said recording medium, for reading the image formed on said recording medium, said line sensor including a plurality of reading elements; and control means for making said image forming means form a test image having a striped pattern on said recording medium, for making said line sensor read the formed test image, for calculating a modulation transfer function on the basis of output from said line sensor, and for determining an operating condition of said image forming means so that the calculated modulation transfer function is optimum.
Claim 13
Dependent Claim
47 words
An image forming apparatus according to claim 9, wherein said control means makes said image forming means form the test image repeatedly under a different operating condition and determines the optimum operating condition on the basis of the calculated modulation transfer function corresponding to each test image.
Claim 14
Dependent Claim
36 words
An image forming apparatus according to claim 9, wherein said image forming means form an image having a plurality of colors, and said control means determines the optimum operating condition for every color in the image.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |