Image forming apparatus

Patent metadata

Field	Value
Publication number	US-12566391-B2
Application number	US-202418793036-A
Country	US
Kind code	B2
Filing date	Aug 2, 2024
Priority date	Aug 4, 2023
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

An image forming apparatus includes a rotatable image bearing member, a developing device including a developing container and a developer carrying member, a rotatable intermediary transfer member, and a carrier collecting device including a rotatable sleeve and a magnet. With respect to a rotational direction of the intermediary transfer member, the collecting device is disposed downstream of a first transfer position where a toner image borne on the image bearing member is transferred onto the intermediary transfer member and upstream of a second transfer position where the toner image borne on the intermediary transfer member is transferred onto a recording material.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
a rotatable image bearing member on which an electrostatic latent image is formed; a developing device including a developing container configured to accommodate a developer containing non-magnetic toner and a magnetic carrier, and a developer carrying member configured to carry the developer for developing the electrostatic latent image, formed on the image bearing member, into a toner image; a rotatable intermediary transfer member onto which the toner image borne on the image bearing member is transferred; a carrier collecting device including a rotatable sleeve provided opposed to the intermediary transfer member and a magnet non-rotationally provided inside the sleeve and configured to collect the carrier on the intermediary transfer member, and a voltage applying portion configured to apply a voltage of the same polarity as a charge polarity of the non-magnetic toner to the sleeve, wherein with respect to a rotational direction of the intermediary transfer member, the collecting device is disposed downstream of a first transfer position where the toner image borne on the image bearing member is transferred onto the intermediary transfer member and upstream of a second transfer position where the toner image borne on the intermediary transfer member is transferred onto a recording material.

2 . An image forming apparatus according to claim 1 , wherein a lowermost end of the carrier collecting device is positioned above the secondary transfer position.

3 . An image forming apparatus according to claim 1 , further comprising:
a rotatable steering roller configured to control a position of the intermediary transfer member with respect to a direction perpendicular to a movement direction of the intermediary transfer member; and a supporting member configured to support an end portion of a rotation shaft of the steering roller, wherein the carrier collecting device is connected to the supporting member so as maintain a relative position to the intermediary transfer member.

4 . An image forming apparatus according to claim 1 , further comprising:
a rotatable second image bearing member on which an electrostatic latent image is formed; a second developing device including a second developing container configured to accommodate a second developer containing non-magnetic toner and a magnetic carrier, and a second developer carrying member configured to carry the second developer for developing the electrostatic latent image, formed on the second image bearing member, into a toner image; and a second carrier collecting device including a rotatable second sleeve provided opposed to the intermediary transfer member and a second magnet non-rotationally provided inside the second sleeve and configured to collect the carrier on the intermediary transfer member, wherein the toner image borne on the second image bearing member is transferred onto the intermediary transfer member, and wherein with respect to the rotational direction of the intermediary transfer member, the second carrier collecting device is disposed downstream of a third transfer position where the toner image borne on the second image bearing member is transferred onto the intermediary transfer member and upstream of the first transfer position.

5 . An image forming apparatus comprising:
a rotatable image bearing member on which an electrostatic latent image is formed; a developing device including a developing container configured to accommodate a developer containing non-magnetic toner and a magnetic carrier, and a developer carrying member configured to carry the developer for developing the electrostatic latent image, formed on the image bearing member, into a toner image; a rotatable intermediary transfer member onto which the toner image borne on the image bearing member is transferred; and a carrier collecting device including a rotatable sleeve provided opposed to the intermediary transfer member and a magnet non-rotationally provided inside the sleeve and configured to collect the carrier on the intermediary transfer member, wherein with respect to a rotational direction of the intermediary transfer member, the collecting device is disposed downstream of a first transfer position where the toner image borne on the image bearing member is transferred onto the intermediary transfer member and upstream of a second transfer position where the toner image borne on the intermediary transfer member is transferred onto a recording material, and wherein a lowermost end of the carrier collecting device is positioned above the secondary transfer position.

6 . An image forming apparatus according to claim 5 , further comprising:
a voltage applying portion configured to apply a voltage of the same polarity as a charge polarity of the non-magnetic toner to the sleeve.

7 . An image forming apparatus according to claim 5 , further comprising:
a rotatable steering roller configured to control a position of the intermediary transfer member with respect to a direction perpendicular to a movement direction of the intermediary transfer member; and a supporting member configured to support an end portion of a rotation shaft of the steering roller, wherein the carrier collecting device is connected to the supporting member so as maintain a relative position to the intermediary transfer member.

8 . An image forming apparatus according to claim 5 , further comprising:
a rotatable second image bearing member on which an electrostatic latent image is formed; a second developing device including a second developing container configured to accommodate a second developer containing non-magnetic toner and a magnetic carrier, and a second developer carrying member configured to carry the second developer for developing the electrostatic latent image, formed on the second image bearing member, into a toner image; and a second carrier collecting device including a rotatable second sleeve provided opposed to the intermediary transfer member and a second magnet non-rotationally provided inside the second sleeve and configured to collect the carrier on the intermediary transfer member, wherein the toner image borne on the second image bearing member is transferred onto the intermediary transfer member, and wherein with respect to the rotational direction of the intermediary transfer member, the second carrier collecting device is disposed downstream of a third transfer position where the toner image borne on the second image bearing member is transferred onto the intermediary transfer member and upstream of the first transfer position.

Assignees

• Canon Kk

Inventors

• Fujita Hideki

Classifications

• G03G15/1605

  using at least one intermediate support (G03G15/1625 takes precedence) · CPC title

• G03G15/0189

  primary transfer to an intermediate transfer belt (G03G15/0184 takes precedence) · CPC title

• G03G15/0131

  for transferring a pattern to a second base · CPC title

• G03G21/10 Primary

  Collecting or recycling waste developer · CPC title

• G03G15/161

  with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent · CPC title