US4542981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Degradation compensation of photoreceptor sensitivity for electrophotographic copying machine
Assignee: Sharp Corp
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Filing: 1984-03-07
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Granted: 1985-09-24
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Expires: 2004-03-07
Abstract
Abstract An electrophotographic copying machine is provided having a photoreceptor, a corona discharger, a lamp, and a compensation circuit. The corona discharger is activated to provide a corona discharge toward the photoreceptor to uniformly and initially charge the surface of the photoreceptor. The lamp is illuminated at the same time as the corona discharge of the corona discharger to improve the charging on the photoreceptor. The compensation circuit is activated to provide an exponential voltage to be applied to the lamp in proportion to the sensitivity degradation of the photoreceptor, to thereby compensate the sensitivity degradation of the photoreceptor.
Inventors
- 👤 Shunju Anzai
- 👤 Yoshiaki Imanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:06
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/0094; G03G15/00; G03G15/02; G03G15/0266; G03G15/0291
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
76 words
An electrophotographic copying machine comprising: photoreceptor means for forming a latent image thereon; corona discharge means for providing corona discharging onto said photoreceptor means; lamp means for emitting light toward said photoreceptor means simultaneously with the discharging of said corona discharge means; and control means for controlling activation of said lamp means so that an amount of light emitted by said lamp means is proportional to an exponential degradation in the sensitivity of said photoreceptor means.
Claim 2
Dependent Claim
76 words
An electrophotographic copying machine comprising: photoreceptor means for forming a latent image thereon; corona discharge means for providing corona discharging onto said photoreceptor means; lamp means for emitting light toward said photoreceptor means simultaneously with the discharging of said corona discharge means; and control means for controlling activation of said lamp means so that an amount of light emitted by said lamp means is proportional to an exponential degradation in the sensitivity of said photoreceptor means.
Claim 3
Dependent Claim
36 words
The electrophotographic copying machine of claim 1, wherein said control means includes means for providing an exponentially changing voltage to said lamp means in accordance with said exponential degradation of the sensitivity of said photoreceptor means.
Claim 4
Dependent Claim
46 words
The electrophotographic copying machine of claim 1, wherein said control means comprises a condenser and means for charging said condenser with an exponentially increasing voltage when said copying machine is not in use and means for exponentially discharging said condenser while said copying machine is used.
Claim 5
Dependent Claim
64 words
The electrophotographic copying machine of claim 1, wherein said control means controls an activation voltage to be applied to a plurality of lamps in said electrophotographic copying machine including a lamp for emitting light toward a document on a document table, a charge removing lamp for emitting light toward said photoreceptor means, and a uniformly emitting lamp for emitting light toward said photoreceptor 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) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |