# US 2015/0177643 A1 · Developing roller, developing device, and image forming apparatus including developing device

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

- Number: US 2015/0177643 A1
- Document ID: US20150177643A1
- Status: Published application
- Kind: A1
- Application number: 14/571,168
- Filed: 2014-12-15
- Published: 2015-06-25
- Earliest claimed: 2013-12-20
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Yasuhiro Oishi; Yuji Kamiyama; Akihiro Watanabe; Tamotsu Shimizu; Yoshinobu Yoneima; Shizuka Okada; Sakae Saito
- Web page: https://patentgrep.com/patent/US20150177643A1

## CPC

- G03G 15/0818: {characterised by the structure of the donor member, e.g. surface properties}
- G03G 15/09: using magnetic brush
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A developing roller includes a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier. In the roller main body, a boehmite layer has been formed on an outer circumferential surface of a base body that is made of a metal including aluminum, by a surface treatment by a boehmite method, and a resin coat layer has been formed on a surface of the boehmite layer, the resin coat layer being made of a resin material having electric conductivity.

## Claims

### Claim 1

A developing roller comprising:
a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier, wherein in the roller main body, a boehmite layer has been formed on an outer circumferential surface of a base body that is made of a metal including aluminum, by a surface treatment by a boehmite method, and a resin coat layer has been formed on a surface of the boehmite layer, the resin coat layer being made of a resin material having electric conductivity.

### Claim 2 (depends on 1)

The developing roller according to claim 1, wherein a product of resistance component Rs [Ω] and electrostatic capacitance component Cs [F] in AC impedance Z of the roller main body is in a range from 8.0×10−7 to 1.8×10−4, the AC impedance Z being obtained when an AC voltage of a predetermined frequency f is applied to between a supporting shaft of the base body and a surface of the roller main body.

### Claim 3 (depends on 1)

The developing roller according to claim 1, wherein
the resin coat layer is formed from nylon resin which contains titanium oxide in a dispersed state.

### Claim 4 (depends on 1)

The developing roller according to claim 1, wherein
the roller main body is in a range from 12 mm to 20 mm in outer diameter.

### Claim 5 (depends on 1)

The developing roller according to claim 1, wherein
surface roughness Ra of the resin coat layer of the roller main body is in a range from 0.21 ∞m to 0.26 ∞m.

### Claim 6 (depends on 1)

The developing roller according to claim 1, wherein
the AC voltage applied to the roller main body is a sine wave of 5 V, and the frequency f is 3.7 kHz.

### Claim 7 (depends on 1)

A developing device comprising:
the developing roller according to claim 1; and
a magnetic roller configured to form a toner layer on a surface of the developing roller via a magnetic brush composed of toner and magnetic carrier.

### Claim 8 (depends on 7)

An image forming apparatus comprising the developing device according to claim 7.