EP0037731A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Development control of an electrostatographic machine
Assignee: Xerox Corp
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Filing: 1981-04-07
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Granted: —
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Expires: 2001-04-07
Abstract
Abstract The present invention relates to an electrostatographic machine having a toner dispensing control (using a sensor approach directly measuring developed images to eliminate toner mass variations), and a bias control maintaining optimum density images on the photoreceptor in spite of changing humidity conditions. Two test targets, each having two test patches, are selectively exposed to provide test data in the photoreceptor image area for suitable sensing and control of thetoner dispensing and bias control loops.
Inventors
- 👤 Louis J. Fantozzi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 11:21
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855; G03G15/50; G03G15/5033; G03G15/5041; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
87 words
A method of controlling the intensity of the image produced by an electrostatographic machine having a developer bias control and a photoreceptive surface, characterised by the steps of: monitoring the intensity of the toner deposited on a test area of the photoreceptive surface; changing the developer bias voltage when a high-intensity toner image is detected, and periodically reducing the change in bias voltage by a chosen amount,and keeping it at the reduced level for a chosen period conditional on the toner intensity not reaching a high-intensity level.
Claim 2
Independent Claim
87 words
A method of controlling the intensity of the image produced by an electrostatographic machine having a developer bias control and a photoreceptive surface, characterised by the steps of: monitoring the intensity of the toner deposited on a test area of the photoreceptive surface; changing the developer bias voltage when a high-intensity toner image is detected, and periodically reducing the change in bias voltage by a chosen amount,and keeping it at the reduced level for a chosen period conditional on the toner intensity not reaching a high-intensity level.
Claim 3
Dependent Claim
35 words
The method of claim 1 characterised in that the step of monitoring the toner density image condition includes comparing an indication of toner density on the photoreceptor surface with a reference high toner density signal.
Claim 4
Dependent Claim
40 words
The method of claim 1 or 2, characterised in that the step of increasing the bias voltage includes adding a substantial voltage to a normal bias voltage and conveying the combined bias voltage to the developer through the bias control.
Claim 5
Independent Claim
56 words
The method of any preceding claim, characterised in that the step of periodically changing the bias control voltage includes periodically sampling the toner image denisty on the photoreceptor to produce a sampling signal, comparing the sampling signal with a normal-density reference signal, and changing the bias control voltage in response to the result of the comparison.
Claim 6
Dependent Claim
20 words
The method of claim 4 characterised by decreasing the bias control voltage in increments down to a normal bias voltage.
Claim 7
Dependent Claim
20 words
The method of claim 5, characterised in that the bias control is deactivated when the bias voltage reaches normal value.
Claim 8
Dependent Claim
17 words
The method of claim 6 characterised by activating the toner dispense control after deactivating the bias control.
Claim 9
Dependent Claim
20 words
The method of claim 6 or 7 characterised by reactivating the bias control when a high toner density is detected.
Claim 10
Dependent Claim
59 words
An electrostatographic machine having a developer bias control (96) and a toner dispense control (98), characterised by means (97) for disabling or inhibiting the toner dispense control until after the electrical bias on the developer (36, 38) has reverted to its normal value from a changed value, the latter being brought about by detection of an unacceptably-high toner density.
Claim 11
Dependent Claim
59 words
An electrostatographic machine having a developer bias control (96) and a toner dispense control (98), characterised by means (97) for disabling or inhibiting the toner dispense control until after the electrical bias on the developer (36, 38) has reverted to its normal value from a changed value, the latter being brought about by detection of an unacceptably-high toner density.
References Cited (Backward Citations)
No citation records indexed.
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