US 7,065,306 B2Granted

Toner residual amount detection apparatus

AssigneeCanon Kabushiki Kaisha

InventorsKazukiyo Akashi, Yoshio Mizuno, Atsushi Chaki, Ryo Hanashi

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Abstract

In order to prevent a toner residual amount from being erroneously judged as “toner present” after the toner residual amount has been judged to be insufficient, a toner residual amount detection apparatus includes a developing device for developing an electrostatic image formed on an image bearing member by a toner, the developing device being provided for movement relative to an apparatus main body, a sensor for outputting information corresponding to the toner residual amount in the developing device, a judging device for comparing the output of the sensor with a reference value to thereby judge the toner residual amount, wherein image forming is inhibited via a predetermined number of times of image forming after the toner residual amount is judged to be not sufficient, and a changing device for changing the reference value to a smaller value with the judgement that the toner residual amount is not sufficient.

Claims14

Dependent claims

A toner residual amount detection apparatus comprising:

a developing device for developing an electrostatic image formed on an image bearing member by a toner, said developing device being provided on and movable with respect to an apparatus main body;
toner residual amount detection means for detecting an amount of residual toner in said developing device, said toner residual amount detection means performing a detection operation at predetermined frequencies in a predetermined period;
counting means for determining whether each of detection results obtained from said toner residual amount detection means is less than a predetermined toner residual amount value and counting a number of times which is determined that the detection result is less than the predetermined toner residual amount value;
control means for, in a case where the number of times counted by said counting means exceeds a reference number of times, determining and displaying that the toner residual amount is insufficient, and for, in a case where a number of times of image forming operation performed after said displaying is equal to or greater than a predetermined number of times, inhibiting the image forming operation;
and
change means for changing the reference number of times to a smaller value in a case where the toner residual amount is insufficient.

3 more elements

A toner residual amount detection apparatus comprising:

a developing device for developing an electrostatic image formed on an image bearing member by a toner, said developing device being provided on and movable with respect to an apparatus main body;
toner residual amount detection means for detecting an amount of residual toner in said developing device, said toner residual amount detection means performing a detection operation during a predetermined period;
calculation means for accumulating a period in which a detection result obtained from said toner residual amount detection means is less than a predetermined toner residual amount value, and calculating a ratio value of the accumulated period to the predetermined period;
control means for, in a case where the ratio value calculated by said calculation means exceeds a reference ratio value, determining and displaying that the toner residual amount is insufficient, and for, in a case where a number of times of image forming operation performed after said displaying reaches a predetermined number of times, inhibiting the image forming operation;
and
change means for changing the reference ratio value to a smaller value in a case where the toner residual amount is insufficient.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/165,206Filed 24 Jun 2005 · division
Priority: JP 2002-1926951 Jul 2002
Published: US 2005/0244173 A13 Nov 2005
Granted: 20 Jun 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G03G 15/0856
Arrangements for testing or measuring developer properties or quality, e.g. charge, size, flowability: detection or control means for the…
G03G 15/086
Detection or control means for the developer level: the level being measured by electro-magnetic means
G03G 2215/0888
Details of powder developing device not concerning the development directly: arrangements for detecting toner level or concentration in the…
G03G
Electrography

Family

Application10/606,228Parent of this division · filed 26 Jun 2003
US 2005/0244173 A1Pre-grant publication · published 3 Nov 2005
US 6,931,217 B2Parent of this division
US 2004/0001724 A1Published application
US 7,065,306 B2This patent

From the US filing history. Foreign family members aren’t listed.