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US 6,959,156 B2Granted
Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorTakao Ogata
Life of this patent
Estimating the term…
Abstract
An image forming apparatus includes a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier, a density sensor for detecting a density of the toner, a control unit for controlling the amount of toner to be supplied to the developing device by comparing an output of the density sensor with a target value, a changing unit for changing the target value when the output of the density sensor falls into an error level, and a recovering unit for supplying the toner based on the target value changed by the changing unit to perform a recovery operation.
Claims7
An image forming apparatus comprising:
- a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier;
- a density sensor for detecting a density of a toner image;
- control means for controlling an amount of toner to be supplied to said developing device by comparing an output of said density sensor with a target value;
- changing means for changing the target value when the output of said density sensor falls into an error level;
- and
- recovering means for supplying the toner based on the target value changed by said changing means to perform a recovery operation,
- wherein when the output of said density sensor falls into the error level, said changing means changes the target value to a second target value, which is lower than a first target value, which is the target value before the output of said density sensor falls into the error level,
- wherein when the output of said density sensor reaches the second target value, said recovering means performs a detection operation by said density sensor, and finishes the recovery operation.
5 more elements
An image forming apparatus comprising:
- a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier;
- a density sensor for detecting a density of a toner image;
- control means for controlling an amount of toner to be supplied to said developing device by comparing an output of said density sensor with a target value;
- changing means for changing the target value when the output of said density sensor falls into an error level;
- and
- recovering means for supplying the toner based on the target value changed by said changing means to perform a recovery operation,
- wherein when the output of said density sensor falls into the error level, said changing means changes the target value to a second target value, which is lower than a first target value, which is the target value before the output of said density sensor falls into the error level, and
- wherein when the output of said density sensor reaches the second target value, said changing means changes the target value to a third target value having a level between the second target value and the first target value, and said recovering means supplies the toner based on the third target value, and continues the recovery operation.
5 more elements
An image forming apparatus comprising:
- a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier;
- a density sensor for detecting a density of a toner image;
- control means for controlling an amount of toner to be supplied to said developing device by comparing an output of said density sensor with a target value;
- changing means for changing the target value when the output of said density sensor falls into an error level;
- and
- recovering means for supplying the toner based on the target value changed by said changing means to perform a recovery operation,
- wherein when the output of said density sensor falls into the error level, said changing means changes the target value to a second target value, which is lower than a first target value, which is the target value before the output of said density sensor falls into the error level, and
- wherein unless the output of said density sensor reaches the second target value in a predetermined time, the recovery operation is stopped and a warning is given.
5 more elements
An image forming apparatus comprising:
- a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier;
- a density sensor for detecting a density of a toner image;
- control means for controlling an amount of toner to be supplied to said developing device by comparing an output of said density sensor with a target value;
- changing means for changing the target value when the output of said density sensor falls into an error level;
- and
- recovering means for supplying the toner based on the target value changed by said changing means to perform a recovery operation,
- wherein when the output of said density sensor falls into the error level, said changing means changes the target value to a second target value, which is lower than a first target value, which is the target value before the output of said density sensor falls into the error level, and
- wherein the following expression is satisfied:
- Ve+(V1−Ve) ×0.5 ≦V2≦Ve+(V1−Ve) ×0.8
- where Ve is the error level, V1 is the first target value, and V2 is the second target value.
7 more elements
An image forming apparatus comprising:
- a developing device for developing an electrostatic image formed on an image bearing member with developer including toner and carrier;
- a density sensor for detecting a density of a toner image;
- control means for controlling an amount of toner to be supplied to said developing device by comparing an output of said density sensor with a target value;
- changing means for changing the target value when the output of said density sensor falls into an error level;
- and
- recovering means for supplying the toner based on the target value changed by said changing means to perform a recovery operation,
- wherein said recovering means performs a detection operation by said density sensor, and finishes the recovery operation.
4 more elements
Dependencies are inferred from the claim text.