Developing assembly and image-forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorKeiko Igarashi
Life of this patent
Estimating the term…
Abstract
In a developing assembly having a developer container, a developer-carrying member, a developer layer thickness control member, a magnetic-field formation means and an agitation means, the developer is a two-component developer which contains at least a binder resin, a colorant, an organometallic compound and a wax and has wax-dispersed non-magnetic toner particles with an average particle diameter of from 2 μm to 10 μm and a magnetic carrier, and the developer-carrying member has been subjected to surface blasting with spherical particles to have a surface having a ten-point average roughness Rz of from D/6 to D/2 where D is the average particle diameter of the magnetic carrier.
Claims15
A developing assembly comprising:
- i) a developer container which holds therein a developer;
- ii) a developer-carrying member which is rotatably provided at an opening of the developer container to hold thereon the developer and transport the developer to a developing zone;
- iii) a developer layer thickness control member which is disposed in non-contact with the developer-carrying member to control the layer thickness of the developer held on the developer-carrying member;
- iv) a magnetic-field formation means which is enclosed inside the developer-carrying member and disposed stationarily to the developer container and which has magnetic poles for simultaneously a) drawing up the developer from the developer container to the developer-carrying member and b) forming a magnetic field for controlling the layer thickness of the developer on the developer-carrying member at its part where it faces the developer layer thickness control member;
- and
- v) an agitation means which agitates the developer held in the developer container;
- said developer being a two-component developer which contains at least a binder resin, a colorant, an organometallic compound and a wax and has wax-dispersed non-magnetic toner particles with an average particle diameter of from 2 μm to 10 μm and a magnetic carrier;
- and
- said developer-carrying member having been subjected to surface blasting with spherical particles to have a surface having a ten-point average roughness Rz of from D/6 to D/2 where D is the average particle diameter of the magnetic carrier.
An image-forming apparatus comprising an image-bearing member, a charging means which charges the image-bearing member electrostatically, an imagewise-exposure means which forms an electrostatic latent image on the image-bearing member thus charged, and a developing assembly which develops the electrostatic latent image by means of a developer into a visible image;
- said developing assembly comprising:
- i) a developer container which holds therein a developer;
- ii) a developer-carrying member which is rotatably provided at an opening of the developer container and is disposed facing the image-bearing member to hold thereon the developer and transport the developer to a developing zone which is the part where it faces the image-bearing member;
- iii) a developer layer thickness control member which is disposed in non-contact with the developer-carrying member to control the layer thickness of the developer held on the developer-carrying member;
- iv) a magnetic-field formation means which is enclosed inside the developer-carrying member and disposed stationarily to the developer container and which has magnetic poles for simultaneously a) drawing up the developer from the developer container to the developer-carrying member and b) forming a magnetic field for controlling the layer thickness of the developer on the developer-carrying member at its part where it faces the developer layer thickness control member;
- and
- v) an agitation means which agitates the developer held in the developer container;
- said developer being a two-component developer which contains at least a binder resin, a colorant, an organometallic compound and a wax and has wax-dispersed non-magnetic toner particles with an average particle diameter of from 2 μm to 10 μm and a magnetic carrier;
- and
- said developer-carrying member having been subjected to surface blasting with spherical particles to have a surface having a ten-point average roughness Rz of from D/6 to D/2 where D is the average particle diameter of the magnetic carrier.
Dependencies are inferred from the claim text.