US5387965A
Expired / Lapsed
US
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Toner concentration control method
Assignee: Ricoh Co Ltd
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Filing: 1992-12-09
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Granted: 1995-02-07
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Expires: 2012-12-09
Abstract
Abstract A toner density control method senses the concentration of a toner image for control formed on a photoconductive element by an optical sensor and, based on the output of the sensor, corrects a target target toner concentration for toner supplement control to be effected in response to an output of a toner concentration sensor mounted on a developing device. When the output Vs of the optical sensor is determined to be greater than a reference value Vs 0 (short toner deposition), the reference value Vt 0 is corrected to smaller one. When Vs determined to be smaller than Vs 0 (excessive toner deposition), Vt 0 is corrected to greater one. In each of such cases, a predetermined amount n·ΔVT is subtracted from or added to the output Vt of the toner concentration sensor of that instant.
Inventors
- 👤 Shin Hasegawa
- 👤 Yasushi Koichi
- 👤 Shinji Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:15
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
160 words
A toner concentration control method comprising the steps of: sensing a density of a toner image for control formed on an image carrier by an optical sensor; sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor mounted on said developing device; correcting a target toner concentration for toner supplement control on the basis of an output of said toner concentration sensor and an output of said optical sensor; wherein the step of correcting the target toner concentration further includes determining a correction value based on said output of said optical sensor and a reference density value; and wherein the step of correcting the target toner concentration further includes determining a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
Claim 2
Dependent Claim
160 words
A toner concentration control method comprising the steps of: sensing a density of a toner image for control formed on an image carrier by an optical sensor; sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor mounted on said developing device; correcting a target toner concentration for toner supplement control on the basis of an output of said toner concentration sensor and an output of said optical sensor; wherein the step of correcting the target toner concentration further includes determining a correction value based on said output of said optical sensor and a reference density value; and wherein the step of correcting the target toner concentration further includes determining a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
Claim 3
Dependent Claim
35 words
The method of claim 1, further including controlling an amount of toner supply to said developing device based on a sensed toner concentration value sensed by said toner concentration sensor and the target toner concentration.
Claim 4
Dependent Claim
168 words
In a toner concentration control method comprising the steps of sensing a density of a toner image for control formed on an image carrier by an optical sensor, comparing an output of said optical sensor with a reference value corresponding to a desired image density, and correcting, based on a result of comparison, a target toner concentration for toner supplement control to be executed in response to an output of a toner concentration sensor which is mounted on a developing device; the method further including determining when the output of said optical sensor and said reference value differ from each other by more than a predetermined amount, and in response to a determination that the output of said optical sensor and said reference value differ from each other by more than said predetermined amount controlling whether or not a toner is supplemented during a subsequent predetermined number of copying cycles based on a result of the comparison of the output of said optical sensor and said reference value.
Claim 5
Dependent Claim
168 words
In a toner concentration control method comprising the steps of sensing a density of a toner image for control formed on an image carrier by an optical sensor, comparing an output of said optical sensor with a reference value corresponding to a desired image density, and correcting, based on a result of comparison, a target toner concentration for toner supplement control to be executed in response to an output of a toner concentration sensor which is mounted on a developing device; the method further including determining when the output of said optical sensor and said reference value differ from each other by more than a predetermined amount, and in response to a determination that the output of said optical sensor and said reference value differ from each other by more than said predetermined amount controlling whether or not a toner is supplemented during a subsequent predetermined number of copying cycles based on a result of the comparison of the output of said optical sensor and said reference value.
Claim 6
Dependent Claim
32 words
The method of claim 3, wherein the step of correcting the target toner concentration further includes determining a correction value based on said output of said optical sensor and said reference value.
Claim 7
Dependent Claim
60 words
The method of claim 4, wherein the step of correcting the target toner concentration further includes determining a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
Claim 8
Dependent Claim
166 words
A toner supply control method comprising: sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor mounted on said developing device; controlling supply of additional toner to said developing device based upon a comparison of a sensed toner concentration and a target toner concentration value; sensing a density of a toner image formed on an image carrier by an optical sensor; and modifying the target toner concentration value based upon both a sensed toner concentration and a sensed toner image density as respectively output by said toner concentration sensor and said optical sensor; wherein the step of modifying the target toner concentration value includes comparing a sensed toner image density with a reference toner density value and determining a correction value based upon the toner density comparison, and wherein a modified target toner concentration value is based upon one of: (1) a sensed toner concentration plus said correction value; and (2) a sensed toner concentration minus said correction value.
Claim 9
Dependent Claim
166 words
A toner supply control method comprising: sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor mounted on said developing device; controlling supply of additional toner to said developing device based upon a comparison of a sensed toner concentration and a target toner concentration value; sensing a density of a toner image formed on an image carrier by an optical sensor; and modifying the target toner concentration value based upon both a sensed toner concentration and a sensed toner image density as respectively output by said toner concentration sensor and said optical sensor; wherein the step of modifying the target toner concentration value includes comparing a sensed toner image density with a reference toner density value and determining a correction value based upon the toner density comparison, and wherein a modified target toner concentration value is based upon one of: (1) a sensed toner concentration plus said correction value; and (2) a sensed toner concentration minus said correction value.
Claim 10
Dependent Claim
142 words
A toner supply control method comprising: sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor stored in said developing device, controlling supply of additional toner to said developing device based upon a comparison of a sensed toner concentration and a target toner concentration value; sensing a density of a toner image formed on an image carrier by an optical sensor; determining a difference between a sensed density as sensed by said optical sensor and a reference toner density value; determining whether said difference is greater than a predetermined difference value; and modifying said target toner concentration value in response to a determination that said difference is greater than said predetermined difference value while maintaining said target toner concentration value in response to a determination that said difference is less than said predetermined difference value.
Claim 11
Dependent Claim
142 words
A toner supply control method comprising: sensing a toner concentration of a developer stored in a developing device by a toner concentration sensor stored in said developing device, controlling supply of additional toner to said developing device based upon a comparison of a sensed toner concentration and a target toner concentration value; sensing a density of a toner image formed on an image carrier by an optical sensor; determining a difference between a sensed density as sensed by said optical sensor and a reference toner density value; determining whether said difference is greater than a predetermined difference value; and modifying said target toner concentration value in response to a determination that said difference is greater than said predetermined difference value while maintaining said target toner concentration value in response to a determination that said difference is less than said predetermined difference value.
Claim 12
Dependent Claim
54 words
The toner supply control method of claim 7, further including a step of at least temporarily overriding the controlling step based upon said comparison of a sensed toner concentration and a target toner concentration, with said overriding step occurring in response to a determination that said difference is greater than said predetermined difference value.
Claim 13
Dependent Claim
35 words
The toner supply control method of claim 8, wherein said overriding step includes suppressing the supply of additional toner when the sensed density of said toner image is greater than said reference toner density value.
Claim 14
Dependent Claim
31 words
The toner supply control method of claim 8, wherein said overriding step includes supplying additional toner when the sensed density of said toner is less than said reference toner density value.
Claim 15
Dependent Claim
54 words
The toner supply control method of claim 8, wherein said overriding step includes suppressing the supply of additional toner when the sensed density of said toner image is greater than said reference toner density value, and supplying additional toner when the sensed density of said toner is less than said reference toner density value.
Claim 16
Dependent Claim
143 words
A developing device including a toner concentration control comprising: an optical sensor for sensing a density of a toner image formed on an image carrier; a toner concentration sensor for sensing a toner concentration of a developer stored in said developing device; control means for correcting a target toner concentration for toner supplement control based on an output of said toner concentration sensor and an output of said optical sensor; wherein said control means includes means for determining a correction value based on said output of said optical sensor and a reference density value; and wherein said control means determines a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
Claim 17
Dependent Claim
143 words
A developing device including a toner concentration control comprising: an optical sensor for sensing a density of a toner image formed on an image carrier; a toner concentration sensor for sensing a toner concentration of a developer stored in said developing device; control means for correcting a target toner concentration for toner supplement control based on an output of said toner concentration sensor and an output of said optical sensor; wherein said control means includes means for determining a correction value based on said output of said optical sensor and a reference density value; and wherein said control means determines a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
Claim 18
Dependent Claim
38 words
The developing device of claim 12, wherein said control means controls an amount of toner supply to said developing device based on a sensed toner concentration value sensed by said toner concentration sensor and the target toner concentration.
Claim 19
Dependent Claim
185 words
A developing device including a toner concentration control comprising: an optical sensor for sensing a density of a toner image formed on an image carrier; a toner concentration sensor for sensing a toner concentration of a developer stored in said developing device; means for comparing an output of said optical sensor with a reference value corresponding to a desired image density, and for correcting a target toner concentration for toner supplement control based on the comparison such that said toner supplement control is executed in response to an output of said toner concentration sensor and said target toner concentration; and means for determining when the output of said optical sensor and said reference value differ from each other by more than a predetermined amount and in response to a determination that the output of said optical sensor and said reference value differ from each other by more than a predetermined amount controlling whether or not a toner is supplemented during a subsequent predetermined number of copying cycles based on a result of the comparison of the output of said optical sensor and said reference value.
Claim 20
Dependent Claim
185 words
A developing device including a toner concentration control comprising: an optical sensor for sensing a density of a toner image formed on an image carrier; a toner concentration sensor for sensing a toner concentration of a developer stored in said developing device; means for comparing an output of said optical sensor with a reference value corresponding to a desired image density, and for correcting a target toner concentration for toner supplement control based on the comparison such that said toner supplement control is executed in response to an output of said toner concentration sensor and said target toner concentration; and means for determining when the output of said optical sensor and said reference value differ from each other by more than a predetermined amount and in response to a determination that the output of said optical sensor and said reference value differ from each other by more than a predetermined amount controlling whether or not a toner is supplemented during a subsequent predetermined number of copying cycles based on a result of the comparison of the output of said optical sensor and said reference value.
Claim 21
Dependent Claim
29 words
The developing device of claim 14, wherein said control means includes means for determining a correction value based on said output of said optical sensor and said reference value.
Claim 22
Dependent Claim
54 words
The developing device of claim 15, wherein said control means determines a corrected target toner concentration by one of: (a) adding said correction value to a sensed toner concentration value sensed by said toner concentration sensor; and (b) subtracting said correction value from a sensed toner concentration value sensed by said toner concentration sensor.
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