Image forming apparatus

Patent metadata

Field	Value
Publication number	US-2018259885-A1
Application number	US-201815958057-A
Country	US
Kind code	A1
Filing date	Apr 20, 2018
Priority date	Mar 13, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

An embodiment provides an image forming apparatus that has a first operation mode and a second operation mode. The first operation mode forms an image on a sheet with toner. The second operation mode decolorizes the toner on the sheet on which the image is formed with a decolorable toner having a decoloring function. In the first operation mode, when the sheet passes through a transfer unit, a transfer bias having the same polarity as that of a charge of the toner is applied to the transfer member and a toner image formed on a surface of the transfer member is transferred to the sheet. In the second operation mode, when the sheet passes through the transfer unit, a cleaning bias having a reverse polarity to that of the transfer bias is applied to the transfer member.

First claim

What is claimed is:

1 . A method for an image forming apparatus having a first operation mode in which an image is formed on a sheet with toner and a second operation mode in which the toner on the sheet on which the image is formed with decolorable toner is decolorized, comprising:
in the first operation mode,
transferring a toner image on the sheet, the toner image is formed on a transfer unit, and
supplying a bias voltage to the transfer unit by a voltage supply unit; and
in the second operation mode,
supplying a cleaning bias having a reverse polarity to that of the transfer bias to the transfer member when the sheet passes through the transfer unit,
supplying a first voltage when the sheet is in contact with the first transfer member, and
supplying the cleaning bias when the sheet is not contact with the transfer member

2 . The method according to claim 1 ,
wherein in the second operation mode, when the sheet is not in contact with the transfer member, the cleaning bias is supplied at a second voltage higher than the first voltage.

3 . The method according to claim 1 ,
wherein in the second operation mode, when the sheet is not in contact with the transfer member, alternately supplying a bias having a same polarity as that of the cleaning bias and a bias having a reverse polarity to that of the transfer bias to the transfer member.

4 . The method according to claim 3 , further comprising:
setting a sheet to be decolorized, wherein the alternately supplying is carried out after decoloring of all the sheets.

5 . The method according to claim 3 ,
wherein when a number of the decolorized sheets reaches a preset number, the alternately supplying is carried out.

6 . The method according to claim 1 , further comprising:
when a number of decolorized sheets reaches a preset number, alternately supplying a bias having a same polarity as that of the cleaning bias and a bias having a reverse polarity to that of the transfer bias to the transfer member.

7 . An image processing method having a first operation mode in which an image is formed on a sheet with toner and a second operation mode in which the toner on the sheet on which the image is formed with decolorable toner is decolorized, comprising:
in the first operation mode,
transferring a toner image on the sheet, the toner image is formed on a transfer unit, and
supplying a bias voltage to the transfer unit by a voltage supply unit; and
in the second operation mode,
supplying a cleaning bias having a reverse polarity to that of the transfer bias to the transfer member when the sheet passes through the transfer unit,
supplying a first voltage when the sheet is in contact with the first transfer member, and
supplying the cleaning bias when the sheet is not contact with the transfer member

8 . The image processing method according to claim 7 ,
wherein in the second operation mode, when the sheet is not in contact with the transfer member, the cleaning bias is supplied at a second voltage higher than the first voltage.

9 . The image processing method according to claim 7 ,
wherein in the second operation mode, when the sheet is not in contact with the transfer member, alternately supplying a bias having a same polarity as that of the cleaning bias and a bias having a reverse polarity to that of the transfer bias to the transfer member.

10 . The image processing method according to claim 9 , further comprising:
setting a sheet to be decolorized, wherein the alternately supplying is carried out after decoloring of all the sheets.

11 . The image processing method according to claim 9 ,
wherein when a number of the decolorized sheets reaches a preset number, the alternately supplying is carried out.

12 . The image processing method according to claim 7 , further comprising:
when a number of decolorized sheets reaches a preset number, alternately supplying a bias having a same polarity as that of the cleaning bias and a bias having a reverse polarity to that of the transfer bias to the transfer member

Assignees

• Toshiba Kk
• Toshiba Tec Kk

Inventors

• Takahashi Koji

Classifications

• B41M7/0009

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• G03G15/5004

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