US 5,086,728 AGranted

Developing apparatus

AssigneeCanon Kabushiki Kaisha

InventorMasahide Kinoshita

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Abstract

A developing apparatus is provided with a developer container, a rotatable developer carrying member, a developer regulating member and an elastic rotatable member. Projections and recesses are provided on the surface of the elastic roller for removing a nonmagnetic toner from a developing sleeve and supplying the nonmagnetic toner to the developing sleeve. The number N per unit length of the projections contacting the sleeve in the direction of rotation of the roller, the width d of the nip portion between the sleeve and the roller, the circumferential speed V.sub.1 of the sleeve, and the circumferential speed V.sub.2 of the roller are set to be: V.sub.2.gtoreq.V.sub.1 /4, and 6.ltoreq.N.times.d.times.(V.sub.1 +V.sub.2)/V.sub.1 .ltoreq.40.

Claims15

Dependent claims

A developing apparatus for developing an electrostatic latent image formed on an image bearing member, said apparatus comprising:

a developer container for receiving a one-component nonmagnetic developer;
a rotatable developer carrying member for carrying the one-component nonmagnetic developer and for conveying the one-component nonmagnetic developer from said developer container to a developing area for developing the electrostatic latent image;
a developer regulating member for regulating the thickness of a layer of the one-component nonmagnetic developer conveyed to the developing area by said rotatable developer carrying member;
and
an elastic rotatable member disposed within said developer container for forming a nip portion with said rotatable developer carrying member at a position upstream from said developer regulating member with respect to the direction of rotation of said developer carrying member, said elastic rotatable member comprising a surface having projections and recesses thereon, and said elastic rotatable member rotating in the same direction as said developer carrying member,
wherein a circumferential speed V.sub.1 (mm/sec) of said rotatable developer carrying member, a circumferential speed V.sub.2 (mm/sec) of said elastic rotatable member, a width d (mm) of the nip portion between said rotatable developer carrying member and said elastic rotatable member, and a number N (/mm) per unit length of the projections on the surface of said elastic rotatable member in the direction of rotation of said elastic rotatable member are set so as to satisfy the relationship:
V.sub.2 .gtoreq.V.sub.1 /4,
and
.ltoreq. N.times.d.times.(V.sub.1 +V.sub.2)/V.sub.1 .ltoreq.40.

6 more elements

A developing apparatus for developing an electrostatic latent image formed on an image bearing member, said apparatus comprising:

a developer container for receiving a one-component nonmagnetic developer;
a rotatable developer carrying member for carrying the one-component nonmagnetic developer and conveying the one-component nonmagnetic developer from said developer container to a developing area for developing the electrostatic latent image, said rotatable developer carrying member triboelectrically charging the one-component nonmagnetic developer to a polarity for developing the electrostatic latent image;
a developer regulating member contacting said rotatable developer carrying member for regulating the thickness of a layer of the one-component nonmagnetic developer conveyed to the developing area by said rotatable developer carrying member;
and
an elastic rotatable member disposed within said developer container for forming a nip portion with said rotatable developer carrying member at a position upstream from said developer regulating member with respect to the direction of rotation of said rotatable developer carrying member, said elastic rotatable member comprising a surface having projections and recesses thereon, and said elastic rotatable member rotating in the same direction as said developer carrying member,
wherein a circumferential speed V.sub.1 (mm/sec) of said rotatable developer carrying member, a circumferential speed V.sub.2 (mm/sec) of said elastic rotatable member, a width d (mm) of the nip portion between said rotatable developer carrying member and said elastic rotatable member, and a number N (/mm) per unit length of the projections on the surface of said elastic rotatable member in the direction of rotation of said elastic rotatable member are set so as to satisfy the relationship:
V.sub.2 .gtoreq.V.sub.1 /4,
and
6.ltoreq.N.times.d.times.(V.sub.1 +V.sub.2)/V.sub.1 .ltoreq.40.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/711,875Filed 7 Jun 1991
Priority: JP 2-22891930 Aug 1990
Granted: 11 Feb 1992
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G03G 15/0808
On a donor element, e.g. belt, roller: characterised by the developer supplying means, e.g. structure of developer supply roller
G03G 15/0815
On a donor element, e.g. belt, roller: characterised by the developer handling means after the developing zone and before the supply, e.g.…
G03G
Electrography

Family

No related US applications are recorded in the indexed filing history.

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