Oki Data Corporation

Oki Electric Industry Co., Ltd.

Takaaki Ebe

Daiki Morimoto

Yoshihiro Hashimoto

Toshiyuki Totsuka

Junichi Kawashima

Kohei Jougataki

A charging device according to one or more embodiments may include: a charging member that is rotatable and provided to be in contact with a contact member. The charging member includes: a shaft; a surface layer to be in contact with the contact member and containing porous particles; and an elastic layer provided between the shaft and the surface layer. A ratio of convex portions formed by the porous particles on the surface layer to a surface area of the surface layer is 68.4% or more.

Charging device and image formation apparatus

A charging device includes a charging member that is rotatable and contacts and electrically charges a surface of a charging target member; and a cleaning member that is rotatable and cleans a surface of the charging member, wherein the cleaning member includes a core bar extending in a lengthwise direction, a foam member that is helically wound around the core bar while forming a gap in the lengthwise direction and contacts the charging member, and a first adhesive agent that is provided between the foam member and the core bar, the first adhesive agent contacting a part of the foam member and another part of the foam member that are formed to adjoin each other in the lengthwise direction via the gap.

Charging device, image forming unit, image forming apparatus, and method of manufacturing cleaning member

An image forming apparatus includes a toner image supporting section and a medium transfer section. The toner image supporting section includes first and second toner image supporting member that support first and second toner images at first and second linear speeds, respectively. The medium transfer section transfers, onto a medium, the first and second toner images respectively supported by the first and second toner image supporting members, to thereby cause the first and second toner images to be superimposed on each other. The following conditional expression (1) is satisfied when the medium transfer section transfers the first and second toner images onto the medium,(1&#x2212;1)/(1&#x3e;(2&#x2212;2)/2&#x2003;&#x2003;(1)where Vd1 is the first linear speed, Vt1 is a first conveyance speed of the medium, Vd2 is the second linear speed, and Vt2 is a second conveyance speed of the medium.

Image forming apparatus

An image forming apparatus includes an image forming section, a transferred member, a transfer roller, and a separator. The image forming section forms a developer image. The transferred member is conveyed in a first direction and the developer image is to be transferred on the transferred member. The transfer roller faces the transferred member, and makes a transition between a biasing state in which the transferred member is biased by the transfer roller and a separated state in which the transfer roller is separated away from the transferred member. The separator starts to separate a medium away from the transferred member after the transfer roller starts making a transition from the biasing state to the separated state, the medium being held between the transferred member and the transfer roller in the biasing state.

Electro-photography image forming apparatus

Provided is an image forming unit that includes: an image supporting member including a photosensitive layer configured to support a latent image; a developer supporting member configured to support a developer, and perform a development process on the latent image with use of the developer; and a developer feeding member including a surface that comes into contact with the developer supporting member, and configured to feed the developer to the developer supporting member. The developer feeding member includes an elastic layer. The elastic layer has a plurality of cells each including an opening that is exposed on the surface, and an area occupancy rate of the openings in area of the surface is in a range from 40% to 85%.

Image forming unit and image forming apparatus

A developing device includes a developer bearing body that rotates in a first direction, and a supply brush roller, out of contact with the body, that also rotates in the first direction. A brush contact member has a first contact portion in contact with bristles of the roller above a first horizontal plane passing through a rotational axis of the roller and upstream in the first rotational direction of the roller of a portion of the roller opposing the body. A thickness adjusting member has a second contact portion in contact with the body below a second horizontal plane passing through a rotational axis of the body and downstream in the first rotational direction of the body of the portion of the roller opposing the body. A first vertical plane passing through the first contact portion is closer to the axis of the roller than is a second vertical plane passing through the second contact portion.

Developing device and image forming apparatus

A developing device includes a developer supporting member abutting against an image supporting member for developing a static latent image on the image supporting member. In a state that a film member is disposed between the image supporting member and the developer supporting member, it is arranged such that the film member is extended with a tensional force N (N) when the image supporting member and the developer supporting member rotate. The tensional force N has a relationship as follows:(&#xd7;exp(0.32&#xd7;&#x2212;16))/&#x2266;11.6where A (mm) is a difference between an outer diameter of a center portion of the developer supporting member and an outer diameter of an end portion of the developer supporting member; B (mm) is a wobble amount of the end portion of the developer supporting member; and F (degree) is an Asker C hardness of the developer supporting member.

Developing device with image supporting member and developer supporting member disposed in specific arrangement, and image forming apparatus

A developing device includes a developer supporting member having an elastic layer and a surface layer, and a supply member for supplying developer to the developer supporting member. The surface layer is formed of a mixture containing at least an acrylic resin and a polyether type urethane resin. The developer supporting member and the supply member are configured so that the following equations are satisfied:20&#x2266;A1&#x2266;800.6&#x2266;D&#x2266;2.045+0.1&#xd7;1&#xd7;&#x2266;65where Ais a weight ratio (%) of the acrylic resin relative to a total weight of the acrylic resin and the polyether type urethane resin, F is an Asker F hardness (degree) of a surface of the supply member, and N is an overlap amount (mm) representing a biting amount of the supply member relative to the developer supporting member.

Developing device with supply member and image forming apparatus

In order to obtain the surface shape which is uniform in each of the circumferential direction and the axial direction without being deviated in one direction on the surface, a developer holding body is provided which is arranged so as to face an image holding body, holds a developer as a layer onto a roughened surface, and supplies the developer in order to develop an image which is formed on the image holding body, and wherein the roughening is executed on the basis of a ratio of cutting depths in a plurality of directions.

Developer holding body and developing apparatus

In an electrophotographic image forming apparatus, a contact-type developing roller contacts a photosensitive drum, a developing blade, a supply roller or the like. If the surface of the developing roller is excessively hard, there is a possibility that a pressure applied between the developing roller and the photosensitive drum or the like may increase, and may cause a filming, i.e., a phenomena in which a toner is degraded and welded to the surface of the developing roller. The filming can be prevented when a JIS-A hardness H(degree) of a resilient layer of the developing roller and a dynamic hardness H(mN/&#x3bc;m) of a surface layer of the developing roller satisfy the following relationship: H&#xd7;H&#x3c;15.

Developer bearing body and image forming apparatus

An image forming section includes an image bearing body that bears an electrostatic latent. An operation status detecting section detects at least one of an operation status in which the image forming section operates and an environmental condition in which the image forming section operates. The operation status includes, for example, the number of printed pages, the density of toner image, and the amount of toner consumed. A print condition setting section sets preliminary print conditions. The preliminary print condition includes a developing voltage, the amount of light emitted from an exposing unit, and a charging voltage. A limit setting section sets a limit value based on the environmental conditions. A print controller compares the preliminary print condition with the limit value to determine an ultimate print condition so that the ultimate print condition is within a predetermined range.

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Tokyo, Japan

Takaaki Ebe