Developing device

Patent metadata

Field	Value
Publication number	US-10416593-B2
Application number	US-201715635407-A
Country	US
Kind code	B2
Filing date	Jun 28, 2017
Priority date	Aug 31, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A developing device includes a developing container, a developing sleeve, a magnet and grooves provided at a surface of the sleeve and formed along a direction crossing a circumferential direction of the sleeve. In a cross-section, each of the grooves is formed by a flat bottom portion contacting a carrier particle and a pair of side surface portions provided in both sides of the flat bottom portion with respect to the circumferential direction of the sleeve and satisfies the following relationship:

r<w <2 r,

2× r<L , and

r /2≤ s <2 r.

In the above, r is a volume-average particle size of the carrier particles, w is a length of the flat bottom portion, L is a width between the side surface portions at the surface of the sleeve, and s is a depth of each of the grooves.

First claim

What is claimed is:

1. A developing device comprising:
a developing container configured to accommodate a developer containing toner and carrier particles;
a cylindrical developing sleeve rotatable while carrying the developer in said developing container;
a magnet provided in said developing sleeve and configured to generate a magnetic force for holding the developer; and
a plurality of grooves provided at a developer carrying surface of said developing sleeve and formed along a direction crossing a circumferential direction of said developing sleeve,
wherein in a cross-section perpendicular to a rotational axis of said developing sleeve, each of the grooves has a shape such that a bottom of the groove contacts one particle and does not contact a plurality of particles simultaneously and that both side surfaces of the groove on an open side are curved.

2. A developing device according to claim 1 , wherein the following relationship is satisfied:
r<w< 2 r,
where r is a volume average particle size of the carrier particles and w is a length of the bottom portion measured in the cross-section perpendicular to the rotational axis of said developing sleeve.

3. A developing device according to claim 1 , wherein the following relationship is satisfied:
2 r<L< 3 r,
where r is a volume average particle size of the carrier particles and L is a width of the opening of each of the grooves measured in the cross-section perpendicular to the rotational axis of said developing sleeve.

4. A developing device according to claim 1 , wherein the following relationship is satisfied:
r/ 2≤ s< 2 r,

where r is a volume average particle size of the carrier particles and s is a depth of each of the grooves.

5. A developing device comprising:
a developing container configured to accommodate a developer containing toner and carrier particles;
a cylindrical developing sleeve rotatable while carrying the developer in said developing container;
a magnet provided in said developing sleeve and configured to generate a magnetic force for holding the developer; and
a plurality of grooves provided at a developer carrying surface of said developing sleeve and formed along a direction crossing a circumferential direction of said developing sleeve,
wherein in a cross-section perpendicular to a rotational axis of said developing sleeve, each of the grooves has a shape such that a bottom of the groove contacts one particle and does not contact a plurality of particles simultaneously.

6. A developing device according to claim 5 , wherein the following relationship is satisfied:
r<w< 2 r,
where r is a volume average particle size of the carrier particles and w is a length of the bottom portion measured in the cross-section perpendicular to the rotational axis of said developing sleeve.

7. A developing device according to claim 5 , wherein the following relationship is satisfied:
2 r<L< 3 r,
where r is a volume average particle size of the carrier particles and L is a width of an opening of each of the grooves measured in the cross-section perpendicular to the rotational axis of said developing sleeve.

8. A developing device according to claim 5 , wherein the following relationship is satisfied:
r/ 2≤ s< 2 r,

where r is a volume average particle size of the carrier particles and s is a depth of each of the grooves.

Assignees

• Canon Kk

Inventors

• Ishida Yusuke
• Iida Takanori
• Takeuchi Yasushi
• Yamada Toshiyuki
• Higashikozono Shiro
• Kakinuma Hiroto
• Kobayashi Toshiya

Classifications

• G03G15/0867

  cylindrical developer cartridges, e.g. toner bottles for the developer replenishing opening · CPC title

• G03G15/0818 Primary

  characterised by the structure of the donor member, e.g. surface properties · CPC title

• G03G15/0928 Primary

  relating to the shell, e.g. structure, composition · CPC title

• G03G15/0812 Primary

  characterised by the developer regulating means, e.g. structure of doctor blade · CPC title

• G03G15/0808

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