US5565995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for correcting a pulse-width-modulated signal in a recording apparatus
Assignee: Canon Inc
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Filing: 1995-05-04
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Granted: 1996-10-15
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Expires: 2015-05-04
Abstract
Abstract An image forming device suitable for use in a laser beam printer includes an image forming unit for forming an image on a photoconductor, and a reproduction unit for reproducing a high density image and a halftone image on the photoconductor. A detector then detects the density of the high density image and the halftone image formed on the photoconductor. A controller controls an image forming condition of the image forming unit based on a detection result by the detector.
Inventors
- 👤 Hiromichi Yamada
- 👤 Masaharu Ohkubo
- 👤 Masaki Ojima
- 👤 Hiroshi Sasame
- 👤 Takashi Kawana
- 👤 Kaoru Seto
- 👤 Hiroshi Mano
- 👤 Tetsuo Saito
- 👤 Atsushi Kashihara
- 👤 Michio Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:52
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4056; H04N1/407; H04N1/4076; H04N1/4078
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
154 words
An image forming apparatus comprising: image forming means for forming an image on an image bearing member; reproduction means for reproducing a high density image and a halftone image on the image bearing member; detecting means for detecting the density of the high density image and the halftone image formed on the image bearing member; control means for controlling an image forming condition of said image forming means based on a detection result by said detecting means; and input means for inputting an image signal, wherein said image forming means includes beam generating means for generating a beam in accordance with the image signal input from said input means, and developing means for developing the image formed on the image bearing member, and wherein said control means controls at least one of the developing bias of said developing means and the drive current of said beam generating means for controlling the image forming condition.
Claim 2
Dependent Claim
154 words
An image forming apparatus comprising: image forming means for forming an image on an image bearing member; reproduction means for reproducing a high density image and a halftone image on the image bearing member; detecting means for detecting the density of the high density image and the halftone image formed on the image bearing member; control means for controlling an image forming condition of said image forming means based on a detection result by said detecting means; and input means for inputting an image signal, wherein said image forming means includes beam generating means for generating a beam in accordance with the image signal input from said input means, and developing means for developing the image formed on the image bearing member, and wherein said control means controls at least one of the developing bias of said developing means and the drive current of said beam generating means for controlling the image forming condition.
Claim 3
Dependent Claim
131 words
An image forming apparatus comprising: image forming means for forming an image on an image bearing member; pattern generation means for generating a predetermined patter, wherein said image forming means forms a halftone image based on the predetermined pattern generated by said pattern generation means; detection means for detecting the density of the halftone image; and adjusting means for adjusting the image forming means based on a detection result by said detecting means, wherein said image forming means forms a solid image based on the predetermined pattern generated by said pattern generation means, and wherein said detecting means detects the density of the solid image, and said adjusting means adjusts the image forming means based on the density of the halftone image and the solid image detected by said detecting means.
Claim 4
Dependent Claim
131 words
An image forming apparatus comprising: image forming means for forming an image on an image bearing member; pattern generation means for generating a predetermined patter, wherein said image forming means forms a halftone image based on the predetermined pattern generated by said pattern generation means; detection means for detecting the density of the halftone image; and adjusting means for adjusting the image forming means based on a detection result by said detecting means, wherein said image forming means forms a solid image based on the predetermined pattern generated by said pattern generation means, and wherein said detecting means detects the density of the solid image, and said adjusting means adjusts the image forming means based on the density of the halftone image and the solid image detected by said detecting means.
Claim 5
Dependent Claim
73 words
An image forming apparatus according to claim 2, wherein said image forming means further comprises a charger for charging the image bearing member, developing means for developing the image formed on the image bearing member, a beam generating means for generating a beam, wherein said adjusting means adjusts at least one of the output of said charger, the developing bias of said developing means and the light quantity of the beam generating means.
Claim 6
Dependent Claim
51 words
An image forming apparatus according to claim 3, wherein said image forming means further comprises input means for inputting image data, and converting means for converting the image data input from said input means and outputting converted image data, wherein said adjusting means adjusts a conversion mode of said converting means.
Claim 7
Dependent Claim
187 words
An electrophotographic image forming apparatus, comprising: converting means for converting an input image data; image forming means for forming an image by an electrophotographic method on the basis of converted image data from said converting means; generating means for generating a first predetermined signal for causing said image forming means to form a high density image, and for generating a second predetermined signal for causing said image forming means to form a halftone image; detecting means for detecting a density of at least the high density image and the halftone image; control means for controlling a condition of an electrophotographic image formation by said image forming means, in accordance with the density of the high density image detected by said detecting means; and correcting means for correcting a conversion characteristic of said converting means in accordance the density of the halftone image detected by said detecting means, wherein said apparatus causes said image forming means to form the halftone image in response to the second predetermined signal and under the condition controlled by said control means in accordance with the density detected for the high density image.
Claim 8
Dependent Claim
187 words
An electrophotographic image forming apparatus, comprising: converting means for converting an input image data; image forming means for forming an image by an electrophotographic method on the basis of converted image data from said converting means; generating means for generating a first predetermined signal for causing said image forming means to form a high density image, and for generating a second predetermined signal for causing said image forming means to form a halftone image; detecting means for detecting a density of at least the high density image and the halftone image; control means for controlling a condition of an electrophotographic image formation by said image forming means, in accordance with the density of the high density image detected by said detecting means; and correcting means for correcting a conversion characteristic of said converting means in accordance the density of the halftone image detected by said detecting means, wherein said apparatus causes said image forming means to form the halftone image in response to the second predetermined signal and under the condition controlled by said control means in accordance with the density detected for the high density image.
Claim 9
Dependent Claim
73 words
An electrophotographic image forming apparatus according to claim 5, wherein said image forming means comprises charging means for uniformly charging an image bearing member, emitting means for emitting a light modulated in accordance with the image data converted by said converting means and for forming a latent image on the image bearing member uniformly charged by said charging means, developing and means for developing the latent image formed on the image bearing member.
Claim 10
Dependent Claim
36 words
An electrophotographic image forming apparatus according to claim 6, wherein said control means controls a light intensity of said emitting means in accordance with the detection result of the high density image by said detecting means.
Claim 11
Dependent Claim
38 words
An electrophotographic image forming apparatus according to claim 6, wherein said control means controls a voltage to be applied to said charging means in accordance with the detection result of the high density image by said detecting means.
Claim 12
Dependent Claim
36 words
An electrophotographic image forming means according to claim 6, wherein said control means controls a developing bias of said developing means in accordance with the detection result of the high density image by said detecting means.
Claim 13
Dependent Claim
25 words
An electrophotographic image forming apparatus according to claim 6, wherein said detecting means detects a density of the image formed on the image bearing member.
Claim 14
Dependent Claim
47 words
An electrophotographic image forming apparatus according to claim 6, further comprising transfer means for transferring the developed latent image on the image bearing member onto a transfer material, wherein said detecting means detects the density of the image transferred on the transfer material by said transfer means.
Claim 15
Dependent Claim
30 words
An electrophotographic image forming apparatus according to claim 5, 6, 7, 8, 9, 10, or 11, further comprising binarizing means for binarizing the image data converted by said converting means.
Claim 16
Dependent Claim
29 words
An electrophotographic image forming apparatus according to claim 12, wherein said binarizing means comprises means for processing the image data, converted by said converting means, by a dither method.
Claim 17
Dependent Claim
36 words
An electrophotographic image forming apparatus according to claim 12, wherein said binarizing means comprises pulse-width modulation means for outputting a pulse signal having a width in accordance with the image data converted by said converting means.
Claim 18
Dependent Claim
184 words
A control method for an apparatus having image forming means for forming an image by electrophotographic method, comprising: a first generating step of generating a first predetermined signal, and forming with said image forming means a high density image in response to the first predetermined signal; a first detecting step of detecting a density of the high density image formed by said image forming means; a control step of controlling a condition of an electrophotographic image formation by said image forming means in accordance with the density of the high density image detected in said first detecting step; a second generating step of generating a second predetermined signal under the condition controlled in said controlling step, and forming with said image forming means a halftone image in response to the second predetermined signal; a second detecting step of detecting a density of the halftone image formed by said image forming means; and a correcting step of correcting a conversion characteristic of converting means for converting an input image data in accordance with the density of the halftone image detected in said second detecting step.
Claim 19
Dependent Claim
184 words
A control method for an apparatus having image forming means for forming an image by electrophotographic method, comprising: a first generating step of generating a first predetermined signal, and forming with said image forming means a high density image in response to the first predetermined signal; a first detecting step of detecting a density of the high density image formed by said image forming means; a control step of controlling a condition of an electrophotographic image formation by said image forming means in accordance with the density of the high density image detected in said first detecting step; a second generating step of generating a second predetermined signal under the condition controlled in said controlling step, and forming with said image forming means a halftone image in response to the second predetermined signal; a second detecting step of detecting a density of the halftone image formed by said image forming means; and a correcting step of correcting a conversion characteristic of converting means for converting an input image data in accordance with the density of the halftone image detected in said second detecting step.
Claim 20
Dependent Claim
71 words
A control method according to claim 15, wherein said image forming means comprises charging means for uniformly charging an image bearing member, emitting means for emitting a light modulated in accordance with the image data converted by said converting means and for forming a latent image on the image bearing member uniformly charged by said charging means, and developing means for developing the latent image formed on the image bearing member.
Claim 21
Dependent Claim
37 words
A control method according to claim 16, wherein in said control step, a light intensity of said emitting means is controlled in accordance with the density detected in said first detecting step of the high density image.
Claim 22
Dependent Claim
39 words
A control method according to claim 16, wherein in said control step, a voltage to be applied to said charging means is controlled in accordance with the density detected in said first detecting step of the high density image.
Claim 23
Dependent Claim
37 words
A control method according to claim 16, wherein in said control step, a developing bias of said developing means is controlled in accordance with the density detected in said first detecting step of the high density image.
Claim 24
Dependent Claim
28 words
A control method according to claim 16, wherein in said first and second detecting steps, a density of the image formed on the image bearing member is detected.
Claim 25
Dependent Claim
54 words
A control method according to claim 16, wherein said image forming means further comprises transfer means for transferring the image formed on the image bearing member onto a transfer material, wherein in said first and second detecting steps, the density of the image transferred on the transfer material by said transfer means is detected.
Claim 26
Dependent Claim
24 words
A control method according to claim 15, wherein said apparatus further comprises binarizing means for binarizing the image data converted by said converting means.
Claim 27
Dependent Claim
27 words
A control method according to claim 22 wherein said binarizing means comprises means for processing the image data, converted by said converting means, by a dither method.
Claim 28
Dependent Claim
34 words
A control method according to claim 22, wherein said binarizing means comprises pulse-width modulation means for outputting a pulse signal having a width in accordance with the image data converted by said converting means.
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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) | 1999-10-15 | 2000-04-15 | 2000-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-15 | 2004-04-15 | 2004-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-15 | 2008-04-15 | 2008-10-15 | $7700.00 | Window Closed / Lapsed |