Patent US5223896A successfully refreshed from Google Patents.
US5223896A
Expired / Lapsed
US
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Image forming apparatus having self-diagnostic function relating to the potential of the photoreceptor
Assignee: Minolta Co Ltd
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Filing: 1992-06-10
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Granted: 1993-06-29
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Expires: 2012-06-10
Abstract
Abstract A copying apparatus for forming a hard copy image through an electrophotographic process includes an image forming apparatus which can form an image on a recording paper in various density levels, and a diagnostic unit for discriminating the image forming apparatus into three states of being capable of forming a proper image, being operable but incapable of forming a proper image, and being incapable of operation. Since the image forming states of the copying apparatus are divided into three stages, appropriate operation is performed in the copying apparatus using the electrophotographic process in response to the state of the machine.
Inventors
- 👤 Tadafumi Shimizu
- 👤 Masahide Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:27
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/55; G03G15/553; G03G15/556; G03G15/50; G03G15/5033; G03G15/5037; G03G15/5075; G03G15/5079; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
138 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor at a prescribed potential; developing means having a developer containing toner and a carrier for supplying said toner to said photoreceptor, said developing means being capable of changing toner density in said developer within a prescribed range; bias means for supplying a prescribed bias potential to said developing means; potential difference adjusting means for adjusting potential difference between said photoreceptor and said developing means; first control means for controlling said potential difference adjusting means so that said potential difference between said photoreceptor and said developing means reaches a prescribed value; and second control means for changing said toner density in said developer when said potential difference between said photoreceptor and said developing means does not reach said prescribed value by said potential difference adjusting means.
Claim 2
Dependent Claim
138 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor at a prescribed potential; developing means having a developer containing toner and a carrier for supplying said toner to said photoreceptor, said developing means being capable of changing toner density in said developer within a prescribed range; bias means for supplying a prescribed bias potential to said developing means; potential difference adjusting means for adjusting potential difference between said photoreceptor and said developing means; first control means for controlling said potential difference adjusting means so that said potential difference between said photoreceptor and said developing means reaches a prescribed value; and second control means for changing said toner density in said developer when said potential difference between said photoreceptor and said developing means does not reach said prescribed value by said potential difference adjusting means.
Claim 3
Dependent Claim
64 words
An image forming apparatus in accordance with claim 1, wherein said developing means comprises: toner supply means for supplying said toner into said developer, detection means for detecting said toner density in said developer, and supply control means for controlling said toner supply means so that said toner density in said developer reaches prescribed target density, said second control means changing said target density.
Claim 4
Dependent Claim
103 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor; developing means having a developer containing toner and a carrier for supplying said toner to said photoreceptor, said developing means being capable of changing toner density in said developer within a prescribed range; potential measuring means for measuring the surface potential of said photoreceptor; toner density control means for changing said toner density when prescribed potential adjustment cannot be performed by said potential control means; and potential control means for adjusting output of said charging means on the basis of the result of said measurement by said potential measuring means.
Claim 5
Dependent Claim
103 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor; developing means having a developer containing toner and a carrier for supplying said toner to said photoreceptor, said developing means being capable of changing toner density in said developer within a prescribed range; potential measuring means for measuring the surface potential of said photoreceptor; toner density control means for changing said toner density when prescribed potential adjustment cannot be performed by said potential control means; and potential control means for adjusting output of said charging means on the basis of the result of said measurement by said potential measuring means.
Claim 6
Dependent Claim
66 words
An image forming apparatus in accordance with claim 3, wherein said developing means comprises: toner supply means for supplying said toner into said developer, density measuring means for measuring said toner density in said developer, and supply control means for controlling said toner supply means so that said toner density in said developer reaches prescribed target density, said toner density control means changing said target density.
Claim 7
Dependent Claim
61 words
In an image forming apparatus for developing a photoreceptor using a developer containing toner and a carrier, an image forming method including the steps of: adjusting a charge voltage so that potential difference between a developing electrode and said photoreceptor reaches a prescribed value; and changing toner density in said developer when said potential difference does not reach said prescribed value.
Claim 8
Dependent Claim
61 words
In an image forming apparatus for developing a photoreceptor using a developer containing toner and a carrier, an image forming method including the steps of: adjusting a charge voltage so that potential difference between a developing electrode and said photoreceptor reaches a prescribed value; and changing toner density in said developer when said potential difference does not reach said prescribed value.
Claim 9
Dependent Claim
34 words
An image forming method in accordance with claim 5, further including a step of measuring the potential of said photoreceptor, said charge voltage being adjusted on the basis of the result of said measurement.
Claim 10
Dependent Claim
35 words
An image forming method in accordance with claim 5, further including a step of measuring said toner density in said developer, said toner density being adjusted on the basis of the result of said measurement.
Claim 11
Dependent Claim
54 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor; measured means for measuring the surface potential of said photoreceptor; cleaning means for cleaning said charging means; and cleaning control means for driving said cleaning means when said surface potential measured by said measuring means does not reach a prescribed value.
Claim 12
Dependent Claim
54 words
An image forming apparatus including: a photoreceptor; charging means for charging said photoreceptor; measured means for measuring the surface potential of said photoreceptor; cleaning means for cleaning said charging means; and cleaning control means for driving said cleaning means when said surface potential measured by said measuring means does not reach a prescribed value.
Claim 13
Dependent Claim
25 words
An image forming apparatus in accordance with claim 8, wherein said charging means has a discharge electrode, and said cleaning means cleans said discharge electrode.
Claim 14
Dependent Claim
103 words
An image forming apparatus in accordance with claim 8, further including: developing means having a developer containing toner and a carrier for supplying said toner to said photoreceptor, supply means for supplying said toner into said developer, density measuring means for measuring density of said toner in said developer, density control means for controlling said toner supply means so that said toner density reaches a prescribed desired value, and second control means for changing said desired value of said toner density when said surface potential does not yet reach said prescribed value after said charging means is cleaned by said cleaning control means.
Claim 15
Dependent Claim
48 words
In an image forming apparatus having a photoreceptor, a cleaning method for charging means, including the steps of: charging said photoreceptor using said charging means; measuring the surface potential of said photoreceptor; and cleaning said charging means when the measured surface potential does not reach a prescribed value.
Claim 16
Dependent Claim
48 words
In an image forming apparatus having a photoreceptor, a cleaning method for charging means, including the steps of: charging said photoreceptor using said charging means; measuring the surface potential of said photoreceptor; and cleaning said charging means when the measured surface potential does not reach a prescribed value.
Claim 17
Dependent Claim
52 words
A cleaning method in accordance with claim 11, further including the steps of: further charging said photoreceptor after said cleaning step, measuring the surface potential of said photoreceptor, and changing the mixing ratio of said toner and said carrier in said developer when said surface potential does not reach said prescribed value.
References Cited (Backward Citations)
US3842273A
Cited
US3997873A
Cited
JPS53136838A
Cited
US4583834A
Cited
US4162396A
Cited
US4277549A
Cited
US4497037A
Cited
JPS58109926A
Cited
US4586147A
Cited
JPS59142559A
Cited
US4549044A
Cited
US4809037A
Cited
US4835738A
Cited
US4855754A
Cited
JPS63296062A
Cited
JPS6463177A
Cited
US4885466A
Cited
JPH01261676A
Cited
US4879577A
Cited
US5089848A
Cited
USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1996-06-28 | 1996-12-28 | 1997-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-28 | 2000-12-28 | 2001-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-28 | 2004-12-28 | 2005-06-29 | $7700.00 | Window Closed / Lapsed |