US 10,241,460 B2Granted

Image forming apparatus

AssigneeCanon Kabushiki Kaisha

InventorsHiroto Nishihara, Shinnosuke Iwadate, Teruhito Kai, Hiromi Shimura, Keita Takahashi

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Abstract

An image forming apparatus including a normal power mode and a power saving mode includes a fixing unit configured to bring first and second rotary members into contact with each other to form a nip portion and fix a toner image onto a sheet with a pressing force of the nip portion. The image forming apparatus executes a rotation operation or a separation operation to separate the first and second rotary members from each other in order to prevent a deformation of the nip portion in the fixing unit. The image forming apparatus measures a time during which the first and second rotary members are in contact with each other without rotating. The image forming apparatus determines whether to execute the separation operation or the rotation operation based on a result of the power mode determination and the measured time.

Claims20

Dependent claims

An image forming apparatus including a first power mode and a second power mode in which power consumption is lower than power consumption in the first power mode, the image forming apparatus comprising:

an image bearing member;
an image forming unit configured to form an image on the image bearing member when an image formation request is received;
a transfer unit configured to transfer onto a sheet the image formed on the image bearing member;
a fixing unit, including a first rotary member and a second rotary member, fix onto the sheet the image transferred by the transfer unit with a pressing force of the nip portion while applying heat via the first rotary member;
a first driving unit configured to rotate one of the first rotary member and the second rotary member;
and
a second driving unit configured to bring the first rotary member and the second rotary member into contact with each other to form a nip portion and separate one of the first rotary member and the second rotary member from the other of the first rotary member and the second rotary member;
and
a control unit configured to cause the first driving unit to execute a rotation operation to rotate one of the first rotary member and the second rotary member in a case where a predetermined time passes while the first rotary member and the second rotary member are in contact with each other without rotating and the image forming apparatus is in the first power mode, whereas the control unit causes the second driving unit to execute a separation operation to separate one of the first rotary member and the second rotary member from the other of the first rotary member and the second rotary member in a case where the predetermined time passes while the first rotary member and the second rotary member are in contact with each other without rotating and the image forming apparatus is in the second power mode,
wherein during the first power mode, power is supplied to the first driving unit and the second driving unit, and
wherein during the second power mode, power is not supplied to the first driving unit and the second driving unit.

8 more elements

an image bearing member;
an image forming unit configured to form an image on the image bearing member when an image formation request is received;
a transfer unit configured to transfer onto a sheet the image formed on the image bearing member;
a fixing unit, including a first rotary member and a second rotary member, fix onto the sheet the image transferred by the transfer unit with a pressing force of the nip portion while applying heat via the first rotary member;
a rotation unit configured to rotate one of the first rotary member and the second rotary member;
and
a contact/separation unit configured to bring the first rotary member and the second rotary member into contact with each other to form a nip portion and separate one of the first rotary member and the second rotary member from the other of the first rotary member and the second rotary member;
and
a control unit configured to cause the rotation unit to execute a rotation operation to rotate one of the first rotary member and the second rotary member in a case where a predetermined time passes while the first rotary member and the second rotary member are in contact with each other without rotating and the image forming apparatus is in the first power mode, whereas the control unit causes the contact/separation unit to execute a separation operation to separate one of the first rotary member and the second rotary member from the other of the first rotary member and the second rotary member in a case where the predetermined time passes while the first rotary member and the second rotary member are in contact with each other without rotating and the image forming apparatus is in the second power mode,
wherein during the first power mode power is supplied to the rotation unit and the contact/separation unit, and
wherein during the second power mode, power is not supplied to the rotation unit and the contact/separation unit.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/610,408Filed 31 May 2017
Priority: JP 2016-1155229 Jun 2016
Published: US 2017/0357204 A114 Dec 2017
Granted: 26 Mar 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G03G 15/80
Apparatus for electrographic processes using a charge pattern: details relating to power supplies, circuits boards, electrical connections
G03G 15/2028
Structural details of the fixing unit in general, e.g. cooling means, heat shielding means: with means for handling the copy material in the…
G03G 15/2032
Structural details of the fixing unit in general, e.g. cooling means, heat shielding means: retractable heating or pressure unit
G03G 15/5004
Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode…:…