# US 9,075,333 B2 · Charging member, process cartridge, and electrophotographic apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,075,333 B2
- Document ID: US9075333B2
- Status: Granted
- Kind: B2
- Application number: 14/288,810
- Filed: 2014-05-28
- Published: 2014-09-18
- Granted: 2015-07-07
- Earliest claimed: 2012-12-12
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Atsushi Uematsu; Tomohito Taniguchi; Taichi Sato
- Web page: https://patentgrep.com/patent/US9075333B2

## CPC

- G03G 15/0233: {Structure, details of the charging member, e.g. chemical composition, surface properties}
- G03G 21/18: using a processing cartridge {, whereby the process cartridge comprises at least two image processing means in a single unit}
- Y10T 428/249973: Mineral element
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Provided is a charging member for suppressing the vibration of a charging roller which occurs owing to a difference in circumferential speed in a longitudinal direction when the roller is rotated to follow a photosensitive member, and suppressing a banding image caused by the vibration of the charging roller over a long period of time. The charging member includes a substrate and an elastic layer. The elastic layer contains a rubber having a polar group and hollow particles each having a shell containing a crystal of calcium carbonate.

## Claims

### Claim 1

A charging member, comprising:
a substrate; and
an elastic layer,
wherein the elastic layer contains
a rubber having a polar group and
a hollow particle having a shell containing a crystal of calcium carbonate.

### Claim 2 (depends on 1)

The charging member according to claim 1, wherein the hollow particle has a porous shell formed of the crystal of calcium carbonate.

### Claim 3 (depends on 1)

The charging member according to claim 1, wherein the hollow particle has a hollowness of 20 volume % or more and 60 volume % or less.

### Claim 4 (depends on 1)

The charging member according to claim 1, wherein the crystal of calcium carbonate has a calcite crystal structure.

### Claim 5 (depends on 4)

The charging member according to claim 4, wherein the calcite crystal structure has a half width of an X-ray diffraction peak of a (104) crystal plane of 0.25° or less.

### Claim 6 (depends on 5)

The charging member according to claim 5, wherein the half width is 0.05° or more.

### Claim 7 (depends on 1)

The charging member according to claim 1, wherein the hollow particle has a volume average particle diameter of 1.0 μm or more and 20.0 μm or less.

### Claim 8 (depends on 1)

The charging member according to claim 1, wherein the rubber having a polar group comprises any one of an epichlorohydrin rubber and an acrylonitrile-butadiene rubber.

### Claim 9 (depends on 1)

An electrophotographic apparatus, comprising:
a charging member; and
an electrophotographic photosensitive member disposed in contact with the charging member,
wherein the charging member comprises the charging member according to claim 1.

### Claim 10 (depends on 1)

A process cartridge integrally holding a charging member and at least an electrophotographic photosensitive member, the process cartridge being configured to be detachable from a main body of an electrophotographic apparatus,
wherein the charging member comprises the charging member according to claim 1.