Image forming apparatus

Patent metadata

Field	Value
Publication number	US-12265354-B2
Application number	US-202318343901-A
Country	US
Kind code	B2
Filing date	Jun 29, 2023
Priority date	Jun 2, 2020
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Provided are an image bearing member; a charging member that charges the image bearing member; an exposure unit that exposes the image bearing member; a developing unit that develops an electrostatic latent image as a developer image by supplying a developer, charged to regular polarity, to the image bearing member; a transfer member that transfers the developer image to a transfer-receiving body; and a collecting member that collects a deposit on the image bearing member downstream of a transfer portion of the image bearing member at which the developer image is transferred to the transfer-receiving body by the transfer member, and upstream of a charging portion of the image bearing member charged by the charging member, in a rotation direction of the image bearing member. After transfer of the developer image to the transfer-receiving body, the developer remaining on the image bearing member is collected by the developing unit.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
an image bearing member;
a charging member that charges the image bearing member;
a first exposure unit that exposes the image bearing member so as to form an electrostatic latent image on the image bearing member;
a developing unit that develops the electrostatic latent image as a developer image by supplying a developer, charged to regular polarity, to the image bearing member;
a transfer member that transfers the developer image from the image bearing member to a recording material;
a brush that forms a brush portion by contacting with the image bearing member downstream of a transfer portion of the image bearing member at which the developer image is transferred to the recording material by the transfer member and upstream of a charging portion of the image bearing member charged by the charging member, in a rotation direction of the image bearing member, and that collects a deposit on the image bearing member and that passes through the developer remaining on the image bearing member without having been transferred to the recording material on the image bearing member; and
a second exposure unit that exposes the image bearing member downstream of the brush portion and upstream of the charging portion of the image bearing member charged by the charging member, in the rotation direction of the image bearing member,
wherein the developer remaining on the image bearing member without having been transferred to the recording material is collected by the developing unit,
wherein the brush has a plurality of bristles, and a base fabric that supports the plurality of bristles,
wherein a density of the bristles of the brush is 110 to 290 kF/inch 2 , and
wherein the brush collects the deposit charged to an opposite polarity to the regular polarity.

2. The image forming apparatus according to claim 1 , wherein the brush collects the deposit that lies, in the triboelectric series, further on the opposite polarity side to the regular polarity, as compared with a position of the brush in the triboelectric series.

3. The image forming apparatus according to claim 1 , wherein the developer has a toner particle that contains a binder resin and a colorant, and
wherein Martens hardness measured under a condition of maximum load of 2.0×10 −4 N is at least 200 MPa and not more than 1100 MPa.

4. The image forming apparatus according to claim 3 , wherein the toner particle has a surface layer containing an organosilicon polymer, and a toner core particle covered by the surface layer, and
wherein a number of carbon atoms directly bonded to a silicon atom in the organosilicon polymer is, on average, at least 1 and not more than 3 per silicon atom.

5. The image forming apparatus according to claim 4 , wherein a fixing ratio of the organosilicon polymer relative to the toner particle is at least 90%.

6. The image forming apparatus according to claim 1 , wherein a distance from the brush portion of the image bearing member to an exposure portion of the image bearing member of which the second exposure unit exposes is closer than a distance from the exposure portion of the image bearing member to the charging portion of the image bearing member in the rotation direction of the image bearing member.

7. The image forming apparatus according to claim 1 , wherein the charging member comes into contact with the surface of the image bearing member.

8. An image forming apparatus, comprising:
an image bearing member;
a charging member that charges the image bearing member;
a first exposure unit that exposes the image bearing member so as to form an electrostatic latent image on the image bearing member;
a developing unit that develops the electrostatic latent image as a developer image by supplying a developer, charged to regular polarity, to the image bearing member;
a transfer member that transfers the developer image from the image bearing member to a recording material;
a brush that forms a brush portion by contacting with the image bearing member downstream of a transfer portion of the image bearing member at which the developer image is transferred to the recording material by the transfer member and upstream of a charging portion of the image bearing member charged by the charging member, in a rotation direction of the image bearing member, and that collects a deposit on the image bearing member and that passes through the developer remaining on the image bearing member without having been transferred to the recording material on the image bearing member; and
a second exposure unit that exposes the image bearing member downstream of the brush portion and upstream of the charging portion of the image bearing member charged by the charging member, in the rotation direction of the image bearing member,
wherein the developer remaining on the image bearing member without having been transferred to the recording material is collected by the developing unit,
wherein the brush has a plurality of bristles, and a base fabric that supports the plurality of bristles,
wherein a density of the bristles of the brush is 110 to 290 kF/inch 2 , and
wherein a distance from the brush portion of the image bearing member to an exposure portion of the image bearing member of which the second exposure unit exposes is closer than a distance from the exposure portion of the image bearing member to the charging portion of the image bearing member in the rotation direction of the image bearing member.

9. An image forming apparatus, comprising:
an image bearing member;
a charging member that charges the image bearing member;
a first exposure unit that exposes the image bearing member so as to form an electrostatic latent image on the image bearing member;
a developing unit that develops the electrostatic latent image as a developer image by supplying a developer, charged to regular polarity, to the image bearing member;
a transfer member that transfers the developer image from the image bearing member to a recording material;
a brush that forms a brush portion by contacting with the image bearing member downstream of a transfer portion of the image bearing member at which the developer image is transferred to the recording material by the transfer member and upstream of a charging portion of the image bearing member charged by the charging member, in a rotation direction of the image bearing member, and that collects a deposit on the image bearing member and that passes through the developer remaining on the image bearing member without having been transferred to the recording material on the image bearing member; and
a second exposure unit that exposes the image bearing member downstream of the brush portion and upstream of the charging portion of the image bearing member charged by the charging member, in the rotation direction of the image bearing member,
wherein the developer remaining on the image bearing member without having been transferred to the recording material is collected by the developing unit,
wherein the brush has a plurality of bristles, and a base fabric that supports the plurality of bristles,
wherein a density of the bristles of the brush is 110 to 290 kF/inch 2 , and
wherein the charging member comes into contact with the surface of the image bearing member.

Assignees

• Canon Kk

Inventors

• Funatani Kazuhiro
• Kobayashi Shinsuke
• Umeda Kensuke
• Watanabe Takanori
• Suzuki Ai

Classifications

• G03G15/0233

  Structure, details of the charging member, e.g. chemical composition, surface properties · CPC title

• G03G15/0131

  for transferring a pattern to a second base · CPC title

• G03G15/0808

  characterised by the developer supplying means, e.g. structure of developer supply roller · CPC title

• G03G2215/022

  using a magnetic brush · CPC title

• G03G21/10

  Collecting or recycling waste developer · CPC title