# US 2011/0280632 A1 · Electrophotographic development apparatus

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- Number: US 2011/0280632 A1
- Document ID: US20110280632A1
- Status: Published application
- Kind: A1
- Application number: 13/106,846
- Filed: 2011-05-12
- Published: 2011-11-17
- Earliest claimed: 2010-05-13
- Inventors: Frederic M. Douglas
- Web page: https://patentgrep.com/patent/US20110280632A1

## CPC

- G03G 15/0812: {characterised by the developer regulating means, e.g. structure of doctor blade}
- G03G 15/065: {Arrangements for controlling the potential of the developing electrode}
- G03G 2215/0122: primary transfer to an intermediate transfer belt
- G03G 2215/0497: Exposure from behind the image carrying surface
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

The present invention is directed to a non-contact, single-component developing system for electrophotographic machines that effectively reduces the effect of adhesion forces on the development process. The developing system of the present invention uses a thin layer forming member where Rz is less than or equal to 6.65 μm. Also, the system uses a predetermined length for the thin layer forming member, to control pressing force by the thin layer forming member on the toner and toner support member. The distance from the contact point to the edge is less than or equal to r×(tan θ). Angle θ is spanned by the contact point and the edge; r is the toner support member radius.

## Claims

### Claim 1

An electrophotographic development apparatus, comprising:
a toner support member; and
a thin layer forming member for forming toner on the toner support member,
wherein a distance L from a contact point of the toner support member to a free edge of the thin layer forming member is set to meet the following equation:
0<L≦r×(tan θ),
where L denotes the distance, r an outer radius of the toner support member, and θ is an angle formed by the point, on the free edge of the thin layer forming member, closest to the toner support member at a position in an upstream side relative to a rotational direction of the toner support member from a contact point of the thin film forming member and the toner support member.

### Claim 2

An electrophotographic development apparatus, comprising:
a toner support member; and
a thin layer forming member for forming toner on the toner support member,
wherein a distance L from a contact point of the toner support member to a free edge of the thin layer forming member is set to meet the following equation:
0<L≦r×(tan θ),
where L denotes the distance, r an outer radius of the toner support member, and θ is an angle formed by the point, on the free edge of the thin layer forming member, closest to the toner support member at a position in an upstream side in an opposite direction from a rotational direction of the toner support member from a contact point of the thin film forming member and the toner support member.

### Claim 3

An electrophotographic development apparatus, comprising:
a toner support member; and
a thin layer forming member for forming toner on the toner support member,
wherein a distance L from a contact point of the toner support member to the free edge of the thin layer forming member is set to meet the following equation:
0<L≦r×(tan θ),
where L denotes the distance, r an outer radius of the toner support member, and θ is an angle formed by the point, on the free edge of the thin layer forming member, closest to the toner support member at a position in a downstream side relative to a rotational direction of the toner support member from a contact point of the thin film forming member and the toner support member.

### Claim 4

An electrophotographic development apparatus, comprising:
a toner support member; and
a thin layer forming member for forming toner on the toner support member,
wherein a surface roughness Rz of the thin layer forming member, on the thin layer forming member surface facing the toner support member, is less than or equal to 6.65 μm.

### Claim 5 (depends on 4)

The electrophotographic development apparatus according to claim 4,
wherein the electrophotographic development apparatus develops a latent image formed on a latent image carrying member, and
a distance L from a contact point of the toner support member to the free edge of the thin layer forming member is set to meet the following equation:
0<L≦r×(tan θ),
where L denotes the distance, r an outer radius of the toner support member, and θ is an angle formed by the point, on the free edge of the thin layer forming member, closest to the toner support member at a position in an upstream side relative to a rotational direction of the toner support member from a contact point of the thin film forming member and the toner support member.

### Claim 6 (depends on 4)

The electrophotographic development apparatus according to claim 4, wherein the surface roughness Rz of the thin layer forming member, on the thin layer forming member surface facing the toner support member, is less than or equal to 1.65 μm.