Patent application number | Description | Published |
20100135695 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder. | 06-03-2010 |
20100142998 | CHARGING ROLLER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS - The present invention provides a charging roller having a stable chargeability and capable of preventing occurrence of “fogging” on an electrophotographic image. The invention relates to a contact-charging type charging roller which includes a conductive support and a surface layer. The surface layer contains a binder, resin particles containing a carbon black dispersed in the binder, and graphitized particles dispersed in the binder; and the surface layer has, on its surface, convex portions derived from the resin particles, and convex portions derived from the graphitized particles. These convex portions have a specific relationship. | 06-10-2010 |
20100166454 | CHARGING MEMBER, PROCESS FOR ITS PRODUCTION, PROCESS CARTRIDGE - Concerned with a charging member in the conductive surface layer of which the conductive particles are so kept from agglomerating as to make charging performance not easily change even where the surface layer expands and contracts repeatedly in various environments. The charging member is a charging member having a conductive substrate and formed on the substrate a conductive elastic layer and a conductive surface layer. The elastic layer contains a polymer having a unit coming from ethylene oxide, and the surface layer contains a binder resin and graphitized particles. The binder resin contains a resin having in the molecule a urethane linkage or a siloxane linkage, or a urethane linkage and a siloxane linkage, and the graphitized particles have a graphite (002) plane lattice spacing of from 0.3362 nm or more to 0.3449 nm or less. | 07-01-2010 |
20110044725 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - A charging member is provided which can inhibit defective images due to poor charging and adhering substances from occurring even after being repeatedly used for a long time, and can inhibit deformation and defective images due to the C set, caused by a change in rotational speed accompanying such deformation even after being left standing in a stopping state for a long time. The charging member includes a conductive support and a surface layer. The surface layer includes a binder and resin particles dispersed in the binder, each resin particle having a depressed portion on its surface. Protrusions resulting from the resin particles are formed on the surface of the surface layer. The protrusions each have a depressed portion resulting from the depressed portion of the resin particle, and the surface of the resin particle is covered with the binder. | 02-24-2011 |
20110305481 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - An object of the present invention is to provide a charging member that brings out stable charging performance over a long period of time and also makes the surface of an electrophotographic photosensitive member not easily come to wear non-uniformly. It is a charging member having a conductive substrate and a conductive resin layer; the conductive resin layer containing a binder, conductive fine particles, and bowl-shaped resin particles each of which has an opening; the bowl-shaped resin particles being contained in the conductive resin layer in such a way as not to be exposed to the surface of the charging member; and the surface of the charging member having concavities derived from openings of the bowl-shaped resin particles and protrusions derived from edges of the openings of the bowl-shaped resin particles. | 12-15-2011 |
20120141162 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer. | 06-07-2012 |
20120177402 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - A charging member, a process cartridge and an electrophotographic apparatus are provided which have been so made as for any C-set images to be kept from occurring; the C-set images occurring in a charging member of an electrophotographic apparatus where the charging member and an electrophotographic photosensitive member have been left to stand in contact with each other over a long period of time. In a charging member having a conductive support and a surface layer, the surface layer is incorporated with a specific compound. | 07-12-2012 |
20120288301 | CHARGING MEMBER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS - A charging member is provided which can not easily cause vibration and can stably charge a photosensitive member, even where a high-frequency alternating-current voltage is applied thereto. It is a charging member having an electrically conductive substrate, an electrically conductive elastic layer and a surface layer, and the elastic layer has, in the order from the substrate side, a first rubber layer and a second rubber layer laminated to the first rubber layer, and, where the natural vibration frequency of the first rubber layer is represented by f | 11-15-2012 |
20130266338 | ELECTROPHOTOGRAPHIC MEMBER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS - The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (—O—C | 10-10-2013 |
20140234764 | ELECTROPHOTOGRAPHIC MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - Provided is an electrophotographic member for an electrophotographic apparatus, which suppresses the occurrence of a banding image caused by uneven charging. The electrophotographic member includes: an electroconductive substrate; and a surface layer, in which: the surface layer includes a binder resin and an aggregate of at least one crystal particle selected from the group consisting of a flaky crystal particle of magnesium carbonate and a flaky crystal particle of calcium carbonate; an edge face of a card house structure formed of the crystal particle is exposed at a surface of the aggregate; a surface of the surface layer includes a convex portion derived from the aggregate; and a surface of the convex portion has unevenness reflecting a shape of the edge face of the card house structure exposed at the surface of the aggregate. | 08-21-2014 |
20140270853 | CHARGING MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - Provided is a charging member for suppressing the vibration of a charging roller which occurs owing to a difference in circumferential speed in a longitudinal direction when the roller is rotated to follow a photosensitive member, and suppressing a banding image caused by the vibration of the charging roller over a long period of time. The charging member includes a substrate and an elastic layer. The elastic layer contains a rubber having a polar group and hollow particles each having a shell containing a crystal of calcium carbonate. | 09-18-2014 |
20140308607 | CHARGING MEMBER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS - The present invention relates to a charging member. The charging member comprises an electro-conductive substrate and an electro-conductive surface layer, wherein the surface layer includes a binder resin, an electro-conductive particle dispersed in the binder resin, and a resin particle that roughens the surface of the surface layer; the surface layer has a plurality of protrusions each derived from the resin particle in the surface thereof; the resin particle that forms the protrusion has a pore inside thereof; has a porosity Vt of porosity is 2.5% by volume or less as a whole; and has a region whose porosity V11 is from 5% by volume to 20% by volume, wherein the region is farthest away from the electro-conductive substrate in the resin particle, and assuming that the resin particle is a solid particle having no pores, the region corresponds to a 11% by volume-occupying region of the solid particle. | 10-16-2014 |
20140334843 | CHARGING MEMBER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS - A charging member including an electro-conductive substrate, an electro-conductive elastic layer, and an electro-conductive surface layer, wherein the elastic layer includes a polymer having a unit derived from ethylene oxide and at least one particle selected from the group consisting of graphite particles and graphitized particles; wherein a particle-exposing portion where the particle is exposed is present on the surface of the elastic layer; the surface of the elastic layer including the particle-exposing portions is coated with the surface layer; the surface layer includes binder resin and resin particles dispersed in the binder resin and has a plurality of protrusions derived from the resin particles on the surface; when the resin particles in the surface layer are orthographically projected onto the surface of the elastic layer, areas other than projected areas of the resin particles on the surface of the elastic layer overlap the particle-exposing portion. | 11-13-2014 |
20150087489 | CHARGING MEMBER, METHOD OF PRODUCING THE SAME, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS - The present invention directs to provide a charging member having a protrusion to which smear is difficult to adhere even in a long-term used, and as a result being capable of exhibiting stable charging performance. The charging member has an electro-conductive substrate and an electro-conductive surface layer, wherein the surface layer includes a binder resin and a resin particle including a plurality of electro-conductive domains inside thereof, the surface layer has a protrusion derived from the resin particle, and the electro-conductive domains are localized in the vicinity of the surface of the resin particle. | 03-26-2015 |