Image forming apparatus

Patent metadata

Field	Value
Publication number	US-2024345516-A1
Application number	US-202418599332-A
Country	US
Kind code	A1
Filing date	Mar 8, 2024
Priority date	Apr 17, 2023
Publication date	Oct 17, 2024
Grant date	—

Abstract

Disclosed is an image forming apparatus which is capable of shifting to a standby state in which a heating rotating member is maintained at a first temperature during non-image forming, and to a sleep state in which a heater is turned off during non-image forming. The image forming apparatus turns on the heater before a predetermined time period elapses from when the image forming apparatus shifts to the sleep state such that the heating rotating member is maintained at a second temperature, which is equal to or less than the first temperature when the predetermined time period elapses from when the image forming apparatus shifts to the sleep state.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
a heating rotating member which has a heater and is heated by the heater; a pressing rotating member which contacts the heating rotating member to form a nip portion and fixes a toner image on a recording material together with the heating rotating member; a first temperature detecting portion which detects a temperature of the heating rotating member; and a control portion which controls the heater based on a detection result of the first temperature detecting portion, wherein the image forming apparatus is capable of shifting to a standby state in which the heating rotating member is maintained at a first temperature during non-image forming, and to a sleep state in which the heater is turned off during non-image forming, and wherein the control portion turns on the heater before a predetermined time period elapses from when the image forming apparatus shifts to the sleep state such that the heating rotating member is maintained at a second temperature, which is equal to or less than the first temperature when the predetermined time period elapses from when the image forming apparatus shifts to the sleep state.

2 . The image forming apparatus according to claim 1 ,
wherein the control portion changes a time period from the shift to the sleep state until the heater is turned on based on the detection result of the first temperature detecting portion.

3 . The image forming apparatus according to claim 1 ,
wherein when the temperature of the heating rotating member at a time when the image forming apparatus shifts to the sleep state is a third temperature, a time period from the shift to the sleep state until the heater is turned is a first time period, and wherein when the temperature of the heating rotating member at a time when the image forming apparatus shifts to the sleep state is a fourth temperature, which is higher than the third temperature, a time period from the shift to the sleep state until the heater is turned on is a second time period, which is longer than the first time period.

4 . The image forming apparatus according to claim 1 ,
wherein the first temperature detecting portion does not detect a temperature of the heating rotating member in the sleep state.

5 . The image forming apparatus according to claim 1 ,
wherein a time period from when the image forming apparatus shifts to the sleep state until the heater is turned on is a first predetermined time period, wherein the control portion turns on the heater after the first predetermined time period elapses from when the image forming apparatus shifts to the sleep state to maintain the heating rotating member at the second temperature during a second predetermined time period, and wherein the image forming apparatus shifts to the sleep state after the second predetermined time period elapses.

6 . The image forming apparatus according to claim 5 ,
wherein the control portion turns on the heater after the first predetermined time period elapses from when the image forming apparatus shifts to the sleep state to maintain the heating rotating member at the second temperature during the second predetermined time period, and wherein the control portion turns on the heater after a third predetermined time period elapses, which is longer than the first predetermined time period, from when the image forming apparatus shifts to the sleep state after the second predetermined time period elapses to get the heating rotating member at a third temperature, which is lower than the second temperature.

7 . The image forming apparatus according to claim 1 ,
rotation of the heating rotating member and rotation of the pressing rotating member are stopped in the sleep state.

8 . The image forming apparatus according to claim 1 , further comprising a second temperature detecting portion which detects a temperature outside the image forming apparatus,
wherein the control portion corrects the predetermined time period based on the temperature outside the image forming apparatus detected by the second temperature detecting portion.

9 . The image forming apparatus according to claim 1 , further comprising a fixing device which fixes an image on the recording material,
wherein a temperature of the heating rotating member is higher than the first temperature when the fixing device fixes an image on the recording material.

10 . The image forming apparatus according to claim 1 ,
wherein the image forming apparatus shifts to the sleep state when the standby state continues for a predetermined time period.

11 . The image forming apparatus according to claim 1 , further comprising an operation portion with which a user can operate a setting of the image forming apparatus,
wherein the image forming apparatus shifts to the sleep state when an operation of the setting for shifting to the sleep state is performed on the operation portion in the standby state.

Assignees

• Canon Kk

Inventors

• Koyama Kengo
• Kimura Toshinori
• Suzuki Teruhiko

Classifications

• G03G2215/00084

  the characteristic being the temperature · CPC title

• G03G15/2064

  combined with pressure · CPC title

• G03G15/205 Primary

  specially for the mode of operation, e.g. standby, warming-up, error (G03G15/2046 takes precedence) · CPC title