US4956669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control apparatus for controlling density of toner in a developing unit
Assignee: Minolta Co Ltd
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Filing: 1989-04-11
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Granted: 1990-09-11
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Expires: 2009-04-11
Abstract
Abstract A control apparatus for controlling concentration of toner incorporated in developing material in a developing unit by means of controlling a toner replenishment to supply the toner in accordance with a toner concentration detected by a toner concentration detecting sensor in a first state wherein the detecting signal of the sensor is normal and to supply the toner by a constant volume at the predetermined period in a second state wherein the detecting signal of the sensor is abnormal.
Inventors
- 👤 Minoru Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:48
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0853; G03G15/0887; G03G15/0891; G03G15/0893
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
142 words
A control apparatus for controlling a concentration of toner incorporated in developing a material in a developing unit, comprising: a toner concentration detecting sensor, provided in the developing unit, for detecting said toner concentration; abnormality discriminating means for discriminating an abnormal state in which said detecting sensor is incapable of detecting an accurate toner concentration, and for outputting an abnormal signal indicating the abnormal state; toner replenishing means for replenishing toner to the developing unit; and control means for controlling said toner replenishing means to replenish the toner in accordance with the toner concentration detected by said toner concentration detecting sensor in a first state wherein said abnormality discriminating means does not output the abnormal signal, and to replenish the toner by a constant volume at a predetermined period in a second state wherein said abnormality discriminating means outputs the abnormal signal.
Claim 2
Dependent Claim
142 words
A control apparatus for controlling a concentration of toner incorporated in developing a material in a developing unit, comprising: a toner concentration detecting sensor, provided in the developing unit, for detecting said toner concentration; abnormality discriminating means for discriminating an abnormal state in which said detecting sensor is incapable of detecting an accurate toner concentration, and for outputting an abnormal signal indicating the abnormal state; toner replenishing means for replenishing toner to the developing unit; and control means for controlling said toner replenishing means to replenish the toner in accordance with the toner concentration detected by said toner concentration detecting sensor in a first state wherein said abnormality discriminating means does not output the abnormal signal, and to replenish the toner by a constant volume at a predetermined period in a second state wherein said abnormality discriminating means outputs the abnormal signal.
Claim 3
Dependent Claim
34 words
A control apparatus of claim 1, wherein said developing unit further comprises a mixing member for mixing the developing material, and said toner concentration detecting sensor arranged in a vicinity of the mixing member.
Claim 4
Dependent Claim
18 words
A control apparatus of claim 2, wherein said mixing member transports the developing material while mixing the same.
Claim 5
Dependent Claim
18 words
A control apparatus of claim 2, further comprising: a cleaning member for cleaning said toner concentration detecting sensor.
Claim 6
Dependent Claim
16 words
A control apparatus of claim 4, wherein said cleaning member is provided on said mixing member.
Claim 7
Dependent Claim
26 words
A control apparatus of claim 1, wherein the toner concentration detecting means detects a variation in magnetic permeability of the toner incorporated in the developing material.
Claim 8
Dependent Claim
39 words
A control apparatus of claim 1, wherein the abnormality discriminating means detects the abnormal state by means of a peaked ripple which does not appear in an output waveform of said toner concentration detecting sensor during the predetermined period.
Claim 9
Dependent Claim
25 words
A control apparatus of claim 1, further comprising: means for informing the abnormal state in response to the abnormal signal from said abnormality discriminating means.
Claim 10
Dependent Claim
152 words
A control apparatus for controlling a concentration of toner incorporated in developing material in a developing unit, comprising: a toner concentration detecting sensor, provided in the developing unit, for detecting said toner concentration; abnormality discriminating means for discriminating an abnormal state in which said detecting sensor is incapable of detecting an accurate toner concentration, and for outputting an abnormal signal indicating the abnormal state; toner replenishing means for replenishing toner to the developing unit; and control means for controlling said toner replenishing means to replenish the toner in accordance with the toner concentration detected by said toner concentration detecting sensor in a first state in which said abnormality discriminating means does not output the abnormal signal, and to replenish the toner by a constant volume without regard to the toner concentration detected by said toner concentration detecting sensor in a second state in which said abnormality discriminating means outputs the abnormal signal.
Claim 11
Dependent Claim
152 words
A control apparatus for controlling a concentration of toner incorporated in developing material in a developing unit, comprising: a toner concentration detecting sensor, provided in the developing unit, for detecting said toner concentration; abnormality discriminating means for discriminating an abnormal state in which said detecting sensor is incapable of detecting an accurate toner concentration, and for outputting an abnormal signal indicating the abnormal state; toner replenishing means for replenishing toner to the developing unit; and control means for controlling said toner replenishing means to replenish the toner in accordance with the toner concentration detected by said toner concentration detecting sensor in a first state in which said abnormality discriminating means does not output the abnormal signal, and to replenish the toner by a constant volume without regard to the toner concentration detected by said toner concentration detecting sensor in a second state in which said abnormality discriminating means outputs the abnormal signal.
Claim 12
Independent Claim
73 words
A method of controlling a concentration of toner incorporated in developing material in a developing unit, comprising the steps of, discriminating an abnormal state in which a detecting sensor for detecting toner concentration is incapable of detecting an accurate toner concentration; stopping a replenishment of toner according to the detecting sensor when the abnormal state is discriminated; and starting replenishment of toner without regard to the toner concentration detected by the detecting sensor.
Claim 13
Independent Claim
73 words
A method of controlling a concentration of toner incorporated in developing material in a developing unit, comprising the steps of, discriminating an abnormal state in which a detecting sensor for detecting toner concentration is incapable of detecting an accurate toner concentration; stopping a replenishment of toner according to the detecting sensor when the abnormal state is discriminated; and starting replenishment of toner without regard to the toner concentration detected by the detecting sensor.
Claim 14
Independent Claim
84 words
A method of controlling a concentration of toner incorporated in developing material in a developing unit, comprising the steps of, discriminating an abnormal state in which a detecting sensor for detecting toner concentration is incapable of detecting real toner concentration; and changing a manner of toner replenishment for the developing unit from a first manner in which the toner is replenished in relation to the concentration detected by the detecting sensor to a second manner in which a constant amount of toner is replenished.
Claim 15
Independent Claim
84 words
A method of controlling a concentration of toner incorporated in developing material in a developing unit, comprising the steps of, discriminating an abnormal state in which a detecting sensor for detecting toner concentration is incapable of detecting real toner concentration; and changing a manner of toner replenishment for the developing unit from a first manner in which the toner is replenished in relation to the concentration detected by the detecting sensor to a second manner in which a constant amount of toner is replenished.
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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) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |