IP Library Granted Patent US 10,915,035
Granted Patent B2
US 10,915,035 · App. 16/305,196 · Granted Feb 9, 2021

Carrier for developing electrostatic latent image, two-component developer, developer for replenishment, image forming device, process cartridge, and image forming method

Inventors: Haruki Murata (Kanagawa, JP); Hiroyuki Kishida (Shizuoka, JP); Toyoaki Tano (Shizuoka, JP); Kenichi Mashiko (Shizuoka, JP); Masato Taikoji (Shizuoka, JP); Mariko Takii (Kanagawa, JP); Yoshihiro Murasawa (Shizuoka, JP)
Assignee: Ricoh Company, Ltd.
G03G9/1139G03G9/0819G03G9/0821G03G9/1131G03G15/08G03G2215/0607
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Quick Facts
Patent No.
US 10,915,035
App. No.
16/305,196
Granted
Feb 9, 2021
Kind
B2
Abstract

A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.

Claims (32)

1. A carrier for developing an electrostatic latent image, the carrier comprising:

a core material particle and a resin layer covering a surface of the core material particle, wherein

the resin layer includes a resin and at least one kind of a fine particle;

the at least one kind of the fine particles includes a conductive fine particle and a chargeable fine particle;

the chargeable fine particle has a long diameter of 400 to 900 nm; and

the chargeable fine particle has a shape factor SF-1 of 160 to 250.

2. The carrier for developing an electrostatic latent image according to claim 1 , wherein the resin layer has a thickness of 0.2 to 2.0 μm.

3. A two-component developer comprising:

the carrier for developing an electrostatic latent image according to claim 1 ; and

a toner.

4. The two-component developer according to claim 3 , wherein the toner is a color toner.

5. An image forming device comprising:

an electrostatic latent image bearer;

a charging unit configured to charge the latent image bearer;

an exposure unit configured to form an electrostatic latent image on the latent image bearer;

a developing unit configured to develop the electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to claim 3 to form a toner image;

a transfer unit configured to transfer the toner image formed on the electrostatic latent image bearer to a recording medium; and

a fixing unit configured to fix the toner image transferred to the recording medium.

6. A process cartridge comprising:

an electrostatic latent image bearer;

a charging unit configured to charge a surface of the electrostatic latent image bearer;

a developing unit configured to develop an electrostatic latent image formed on the electrostatic latent image bearer using the two-component developer according to claim 3 ; and

a cleaning unit configured to clean the electrostatic latent image bearer.

7. An image forming method comprising:

forming an electrostatic latent image on an electrostatic latent image bearer;

developing the electrostatic latent image formed on the electrostatic latent image bearer with the two-component developer according to claim 3 to form a toner image;

transferring the toner image formed on the electrostatic latent image bearer to a recording medium; and

fixing the toner image transferred to the recording medium.

8. The carrier of claim 3 , wherein the chargeable fine particle exhibits reverse chargeability with respect to the toner and imparts negative chargeability to the toner through friction with the toner.

9. A developer for replenishment comprising a carrier and a toner, wherein

the developer includes 2 to 50 parts by mass of the toner relative to 1 part by mass of the carrier, and

the carrier is the carrier for developing an electrostatic latent image according to claim 1 .

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 28, 2018
From: MURATA, HARUKI; KISHIDA, HIROYUKI; TANO, TOYOAKI; MASHIKO, KENICHI; TAIKOJI, MASATO; TAKII, MARIKO; MURASAWA, YOSHIHIRO
To: RICOH COMPANY, LTD.
Reel/Frame 047606/0498 →
Priority Claims (1)
JP 2016-108698 · May 31, 2016 · national
Continuity (1)
Related Publication 20200183297A1 · Jun 11, 2020