Canon Kabushiki Kaisha

Kazunori Saiki

Masayoshi Shimamura

Yasuhide Goseki

Satoshi Otake

Kenji Fujishima

Naoki Okamoto

Yasutaka Akashi

Michiko Orihara

Minoru Ito

Nene Dojo

Tatsuya Nakamura

Michihisa Magome

Eriko Yanase

Yusutaka Akashi

Mayoko Maruyama

Takuya Toyooka

A developer carrying member is provided which, even in continuous copying over a long term and also even under different environmental conditions, do not cause any charge-up of toner, and prevent the toner from melt-adherent to the developer carrying member surface and developer layer thickness control member surface to maintain the state of uniform coating of a developer having a toner and to make the toner uniformly and quickly triboelectrically charged, so as to obtain high-grade images free of any image density decrease, image density non-uniformity, sleeve ghosts, fog and vertical streaks during running service. Provided are a developer carrying member having a substrate and a resin coat layer on the surface of the substrate, which resin coat layer contains at least a binder resin and a carbon black, where the graphite (002) plane obtained from X-ray diffraction of the carbon black has a lattice spacing of from 0.3370 nm or more to 0.3450 nm or less; and a developing assembly having such a developer carrying member.

Developer carrying member and developing assembly

In a developer carrying member used in a developing apparatus by means of which an electrostatic latent image formed on an electrostatic latent image bearing member is developed with a developer to render it visible, the developer carrying member has at least a substrate and a resin coat layer formed on the substrate surface, and the resin coat layer contains at least a binder resin and graphitized particles. The surface of the resin coat layer has an average value A and a standard deviation &#x3c3; of 100&#x2266;A&#x2266;800 (N/mm) and &#x3c3;&#x3c;30 (N/mm), respectively.

Developer carrying member and developing apparatus

The present invention relates to a developer carrying member for carrying a developer having at least a substrate and a resin-coated layer formed on the surface of the substrate. The developer carrying member is the one which carries a one-component developer to visualize the electrostatic latent image carried by the electrostatic latent image carrying member, the resin-coated layer contains at least a binder resin, graphitized particles and roughing particles, the graphitized particles has 0.20 to 0.95 of graphitization degree (p(002)), and wherein in the surface configuration of the resin-coated layer as measured by use of focusing optical laser, the volume (B) of a microtopographical region defined by a certain area (A) of the microtopographical region without convexity formed by the roughing particles meets the following relationship 4.5&#x2266;B/A&#x2266;6.5, and the resin-coated layer has 0.9 to 2.5 &#x3bc;m of arithmetic mean roughness (Ra).

Developer carrying member and developing method by using thereof

The present invention relates to a developer carrying member for carrying a developer having at least a substrate and a resin-coated layer formed on the surface of the substrate. The developer carrying member is the one which carries a one-component developer to visualize the electrostatic latent image carried by the electrostatic latent image carrying member, the resin-coated layer contains at least a binder resin, graphitized particles and roughing particles, the graphitized particles has 0.20 to 0.95 of graphitization degree (p (002)), and wherein in the surface configuration of the resin-coated layer as measured by use of focusing optical laser, the volume (B) of a microtopographical region defined by a certain area (A) of the microtopographical region without convexity formed by the roughing particles meets the following relationship 4.5&#x2266;B/A&#x2266;6.5, and the resin-coated layer has 0.9 to 2.5 &#x3bc;m of arithmetic mean roughness (Ra).

A developer carrier is capable of stably charging a toner over a long term without change in physical surface shape and composition. The developer carrier has at least a substrate and resin coating layer formed on a surface of the substrate. The resin coating layer includes at least graphitized particles (i) with a degree of graphitization p() of 0.20 to 0.95 and an indentation hardness HUT [] of 15 to 60 or graphitized particles (ii) with a degree of graphitization p() of 0.20 to 0.95 and an average circularity SF-of 0.64 or more.

Developer carrier, developing device using the developer carrier, and process cartridge using the developer carrier

A developing method is provided in which a developer is carried on a developer carrying member, a thin layer of the developer is formed thereon and a latent image on a latent image bearing member is developed with a developer. The developer is composed of magnetic toner particles containing a binder resin and a magnetic powder. The magnetic powder has a saturation magnetization of 67.0 Am/kg to 75.0 Am/kg in a magnetic field of 79.6 kA/m (1,000 oersteds) and has a residual magnetization of 4.5 Am/kg or less. In the surface profile of the conductive resin coat layer of the developer carrying member, the relationship 1.00&#x2266;S/A&#x2266;1.65 is satisfied where S is a surface area of regions zoned by an area A of microscopic unevenness regions from which parts exceeding a reference plane by 0.5&#xd7;r (r: weight average particle diameter (&#x3bc;m) of a toner used) or more have been excluded.

Developing method and developing assembly

In a developing assembly, a process cartridge and an image-forming method, a specific developer and a specific developer-carrying member are used in combination. The developer comprises toner particles containing at least a binder resin and a colorant, and conductive fine particles; the toner particles having a Circularity a of less than 0.970 as found from the following expression:Circularitywhere Lrepresents the circumferential length of a circle having the same projected area as a particle image, and L represents the circumferential length of a projected image of a particle. The developer-carrying member has at least a substrate and a resin coat layer formed on the substrate; the resin coat layer containing at least a coat layer binder resin and a positively chargeable material.

Developing assembly, process cartridge and image-forming method

A developing assembly is disclosed having at least a developer container, a developer-carrying member and a developer layer thickness regulation member, wherein the developer is composed mainly of toner particles containing at least a binder resin and a colorant, and conductive fine particles, and the developer-carrying member has a substrate and a surface layer formed on the substrate of a non-magnetic metal, an alloy or a metallic compound. This developing assembly causes no sleeve ghost, enables electrostatic latent images to be faithfully developed, causes no fading phenomenon, and enables high-density images to be formed in every environment. Also disclosed are a process cartridge having the developing assembly and the latent-image-bearing member integrally set as one unit detachably mountable on the main body of an image-forming apparatus, and an image-forming method making use of the features of this developing assembly.

In a developing assembly including a two-component developer container and a developer-carrying member, the developer-carrying member has at least a substrate and a resin coat layer formed on the substrate surface, and the resin-coat layer contains at least a binder resin and solid particles for making the resin-coat-layer surface uneven. The solid particles have an average circularity of 0.64 or more, which is the average value of the values calculated according to the equationCircularity=(4&#xd7;)/{()&#xd7;&#x3a0;},(wherein ML represents the Pythagorean-method maximum length of a particle projected image, and A represents the projected area of a particle image), and the resin-coat layer has a surface roughness fulfilling specific conditions attributable to the solid particles. Also disclosed are an image-forming apparatus and a process cartridge which employ the developing assembly.

Developing assembly, image-forming apparatus and process cartridge

A used developer-carrying member having a resin coating layer on a substrate is regenerated through a step of scraping the resin coating layer of the used developer-carrying member to form a developer-carrying member surface having unevenness showing a central line-average roughness Ra of at most 0.8 &mgr;m, and a step of coating the developer-carrying member surface having the unevenness with a coating layer of a resinous composition comprising at least a binder resin and electroconductive fine powder. The regenerated developer-carrying member can be reinstalled in a developing apparatus and subjected to repetitive electrophotographic image forming cycles.

Developer-carrying member, method for regeneration thereof and developing apparatus

A developing apparatus has a developer container for holding a developer, a developer carrying member for carrying a positively chargeable developer held in the developer container and transporting the developer to a developing zone and a developer layer-thickness regulating member for regulating the thickness of a positively chargeable developer layer to be formed on the developer carrying member. The developer carrying member has at least a substrate and a resin coat layer formed of a resin composition on the surface of the substrate. The resin composition contains at least (I) a binder resin, (II) a conductive fine powder, (III) spherical particles having a number-average particle diameter of from 0.3 &mgr;m to 30 &mgr;m and (IV) a quaternary ammonium salt compound which is positively chargeable to iron powder.

Developing apparatus, apparatus unit, and image forming method

A developing apparatus is disclosed which has a developer container, a developer carrying member for carrying a positively chargeable developer held in the developer container and transporting the developer to a developing zone, and a developer layer-thickness regulating member for regulating the thickness of a developer layer formed on the developer carrying member. The developer carrying member has a resin coat layer formed of a resin composition containing at least a resin selected from the group consisting of a phenol resin and a polyamide resin, a conductive material and a quaternary ammonium salt compound which is positively chargeable to iron powder. The resin composition may contain a urethane resin in place of the phenol resin and polyamide resin.

A developer carrying member for carrying a developer is includes a substrate and a resin coat layer which is formed on the surface of the substrate and contains a binder resin and a conductive fine powder. The binder resin is composed of a copolymer having a monomeric unit of a methyl methacrylate monomer (M) and a monomeric unit of a nitrogen-containing vinyl monomer (N). A copolymerization molar ratio of the methyl methacrylate monomer (M) to the nitrogen-containing vinyl monomer (N) in the copolymer fulfills the following condition: M:N=4:1 to 999:1. The binder resin has a weight-average molecular weight (Mw) of from 3,000 to 50,000.

Developer carrying member for carrying developer, apparatus unit

A developer carrying member is comprised of a substrate and a coat layer which covers the surface of the substrate. The coat layer contains at least a binder resin, conductive spherical particles having a number average particle diameter of from 0.3 .mu.m to 30 .mu.m and a true density of 3 g/cm.sup.3 or below, and a nitrogen-containing heterocyclic compound, the particles and the compound being dispersed in the binder resin.

Growing community of inventors

Kanagawa, Japan

Kazunori Saiki