US5081498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Humidity compensation in electrophotographic printing by measuring the dielectric characteristics of the development mixture
Assignee: Xerox Corp
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Filing: 1991-01-10
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Granted: 1992-01-14
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Expires: 2011-01-10
Abstract
Abstract A developer unit which stores a supply of developer material has a capacitance cell positioned therein contacting the developer material. The capacitance cell measures the change in capacitance of the developer material and generates a signal indicative thereof. The capacitance change is caused by a change in the dielectric characteristics of the developer material due to changes in the moisture content thereof. This signal, in combination with a signal indicating the concentration of toner particles in the developer material, is used to control various processing stations in the printing machine employing the developer unit.
Inventors
- 👤 Jan Bares
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:46
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0851
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
An electrophotographic printing machine of the type having a plurality of processing stations with one of the stations being a developer station storing a supply of developer material comprising at least carrier granules and toner particles for developing a latent image recorded on an image receiving member with the toner particles, wherein the improvement includes: means, in contact with the developer material in the developer station, for measuring the developer material dielectric characteristics and generating a signal indicative thereof which corresponds to changes in the moisture content of the developer material; means for detecting the concentration of toner particles in the developer material and generating a signal indicative thereof; and means, responsive to the signal from said measuring means and the signal from said detecting means, for controlling discharge of toner particles into the developer station.
Claim 2
Dependent Claim
136 words
An electrophotographic printing machine of the type having a plurality of processing stations with one of the stations being a developer station storing a supply of developer material comprising at least carrier granules and toner particles for developing a latent image recorded on an image receiving member with the toner particles, wherein the improvement includes: means, in contact with the developer material in the developer station, for measuring the developer material dielectric characteristics and generating a signal indicative thereof which corresponds to changes in the moisture content of the developer material; means for detecting the concentration of toner particles in the developer material and generating a signal indicative thereof; and means, responsive to the signal from said measuring means and the signal from said detecting means, for controlling discharge of toner particles into the developer station.
Claim 3
Dependent Claim
19 words
A printing machine according to claim 1, wherein said measuring means detects the change in the developer material impedance.
Claim 4
Dependent Claim
21 words
A printing machine according to claim 1, wherein said measuring means detects the change in the capacitance of the developer material.
Claim 5
Dependent Claim
27 words
A printing machine according to claim 3, wherein said measuring means includes a capacitance cell positioned in the developer station so that developer material continuously flows therethrough.
Claim 6
Dependent Claim
102 words
A developer unit, including: means for storing a supply of developer material comprising at least toner particles and carrier granules; means, positioned in said storing means and contacting the developer material therein, for measuring the developer material dielectric characteristics and generating a signal indicative thereof which corresponds to changes in the moisture content of the developer material; means for detecting the concentration of toner particles in the developer material and generating a signal indicative thereof; and means, responsive to the signal from said measuring means and the signal from said detecting means, for controlling discharge of toner particles into said storing means.
Claim 7
Dependent Claim
102 words
A developer unit, including: means for storing a supply of developer material comprising at least toner particles and carrier granules; means, positioned in said storing means and contacting the developer material therein, for measuring the developer material dielectric characteristics and generating a signal indicative thereof which corresponds to changes in the moisture content of the developer material; means for detecting the concentration of toner particles in the developer material and generating a signal indicative thereof; and means, responsive to the signal from said measuring means and the signal from said detecting means, for controlling discharge of toner particles into said storing means.
Claim 8
Dependent Claim
19 words
A developer unit according to claim 5, wherein said measuring means senses the change in the developer material impedance.
Claim 9
Dependent Claim
19 words
A developer unit according to claim 6, wherein said measuring means senses the change in the developer material capacitance.
Claim 10
Dependent Claim
27 words
A developer unit according to claim 7, wherein said measuring means includes a capacitance cell positioned in the developer station so that developer material continuously flows therethrough.
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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) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |