Sharp Kabushiki Kaisha Corporation

Atsushi Inoue

Takayuki Yamanaka

Hiroshi Tatsumi

Toshihide Ohgoshi

Jitsuo Masuda

Takashi Sakai

Wataru Yoshida

Tadashi Iwamatsu

Eiichi Kido

Toshio Nishino

Nobuyuki Azuma

Masanori Yamada

Toshihiko Takaya

Hiroshi Ishii

Yasuyuki Ishiguro

Kazuhiro Matsuyama

Masahiro Sakai

Fumito Mizoguchi

Keiji Kato

Keiji Yasuda

Taisuke Kamimura

Hiroaki Nakaya

Shigeyuki Wakada

Yuichi Kazaki

Hideaki Fujita

Katsumi Adachi

Takahiko Kimura

Tetsunori Mitsuoka

Tetsuro Toyoshima

Yukihito Nishio

Hiroaki Yoshida

Nobuhiko Nakano

Kazuhiko Furukawa

Kouji Shinkawa

Keiji Katoh

Junji Morimoto

Tetsuyuki Ueda

Mikie Kobayashi

Humito Mizoguchi

An developing device in which a developing roller develops an electrostatic latent image on a photo conductor; a developing roller driving unit rotates the developing roller in a forward direction and in a backward direction respectively while development is performed and not performed; a thickness regulating member, which is pressed against a surface of the developing roller, regulates a thickness of developer adhered to the surface of the developing roller; and a suppression unit suppresses a pressing force of the thickness regulating member when the developing roller is rotating in the backward direction.

Developing device having thickness regulating member and image forming apparatus

A developing device includes a developer tank, a developing roller, a supply roller, a stirring member, and a doctor blade. The developing device is provided with: a cleaning member detachably provided on a contact portion of the doctor blade with the developing roller, which slides to rub a surface of the doctor blade upon contacting; a supporting section for supporting the cleaning member so as to be capable of being attached to and detached from the contact portion of the doctor blade with the developing roller; and a driving mechanism for moving the cleaning member so as to be attached to and detached from the contact portion of the doctor blade with the developing roller.

Developing device for prevention of coagulate toner adherence and image forming apparatus using the developing device

A state detection mechanism includes a movable member, a spring member, a fringesection, and a stopper member. The spring member displaces the movable member arranged at the first predetermined position to a second predetermined position by applying restoration force in a D direction to the movable member. The fringe section restricts the displacement by abutting to a protrusion member formed on the movable member arranged at the first predetermined position. The stopper member restricts rotation of the movable member, which rotates around an axis that extends in a D direction, by abutting to the protrusion member formed on the movable member arranged at the first predetermined position. When torque is transmitted to the movable member from a shaft, the movable member rotates wound an axis that extends in the D direction, and the protrusion member and the stopper member abut to each other.

State detection mechanism

The process frame body has the guide portion, and the development device has the to-be-guided shaft. When the process frame body is unattached to the apparatus main body, the guide portion of the development device is absent, thus preventing proper attachment and positioning of the development device. The convex engagement portion is formed integrally with the development device so as to jut into the attachment path for the process frame body. This prevents attachment of the process frame body when the development device is attached first. If users try to attach the process frame body after attachment of the development device, the convex engagement portion interferes with the process frame body, thus preventing attachment of the process frame body.

Image forming apparatus with arrangement for controlling assembly order

A detection mechanism is provided with a sealing member made of elastic material for preventing toner leakage between (a) a pierced wall surface of a toner tank through which a rotating shaft is inserted and (b) a second side plate provided on the rotating shaft. With this structure, a flat splicing surface of the sealing member is made to closely contact a second side plate that can be coated with a high lubricant member whose frictional forces is small. When a sealing force of the sealing member is strongly compressed, the sealing member prevents toner from coming into the sliding surface.

Developer detection device and printer

A toner cartridge stored in a developer casing includes a biasing force generating device, an actuating rod that switches the biasing device between an active state and a non-active state by one movement of a release member. A developer casing swings by the movement of the actuating rod and presses a developing roller with appropriate pressure to a photosensitive drum. There is a lock member that is restrained from moving by the movement of the actuating rod. The structure recited is capable of inserting and fixing the developer casing to an image forming device. Also, by one restore movement of the release member, the photosensitive drum and the developing roller are separated and the lock is released, thereby enabling removal/exchange of the developer casing.

Image forming device and toner device

Elastic members are fixed at one end to the housing of an image forming apparatus while their distal ends extend into the framework of the developing unit. When a toner cartridge is fitted to the framework of a developing unit, the distal ends of the elastic members abut the top surface of the toner cartridge, so that the elastic members are compressed to produce repulsive force, which in turn causes the developing unit to rotate clockwise about a support so as to bring the developer roller into pressing contact with a photoconductor.

Image forming apparatus with members for holding a cartridge

A developing apparatus capable of supplying a uniform thin layer of toner and of preventing toner scattering and leakage is provided, where the developing apparatus includes a supply roller for supplying toner to an outer peripheral surface of a toner carrier, the toner carrier for transferring the supplied toner by rotation and a layer thickness controlling member for controlling a thickness of the layer of the supplied toner at a predetermined value while making slide contact with the outer peripheral surface of the toner carrier via the toner, wherein the thin toner layer is supplied to an electrostatic latent image on an image carrier. The layer thickness controlling member is formed of an elastic plate to have a bent portion convex toward the toner carrier. The layer thickness controlling member is held by sealing members so that the bent portion makes elastic contact with the toner carrier outer peripheral surface over a nearly entire length of the toner carrier.

Developing apparatus

In image forming apparatuses producing recycled toner from residual toner and recycling the recycled toner, the toner composition changes, and the toner properties worsen, because the external additive contained in the collected residual toner that is collected with a cleaning portion decreases during the image formation. The residual toner that has been collected with the cleaning portion is conveyed through a conveyance path to a collected residual toner storage, and external additive is supplemented from an external additive cartridge, and mixed with being stirred to produce recycled toner. In a fresh toner storage, fresh toner and recycled toner are stirred, and when the amount of toner in a developing portion drops below a predetermined amount, toner is conveyed from the fresh toner storage through a conveyance path to the developing portion. The toner that has been conveyed to the developing portion is supplied to a photosensitive drum.

Image forming apparatus including system for recycling toner

A developing device, includes; a developing roller supporting and conveying mono component toner to a photoreceptor having a static latent image; a supplying roller pressed against the developing roller and rotated so as to supply the toner to the developing roller. In order to perform beneficial supply of the toner to the developing roller, bias voltages are applied so as to generate an electric field which will cause the toner between the developing roller and the supplying roller to be attracted to the developing roller. At a predetermined time before completion of development, the bias voltage applied to the supplying roller is switched so as to create an electric field which will cause the toner to be attracted to the supplying roller. Thus the toner residing between the developing roller and supplying roller after development is removed, whereby it is possible to prevent toner from sticking to that area on the developing roller, after development. Another configuration further includes a cleaning roller abutted on the supplying and regulating rollers. When development is completed, rotation of the developing roller is stopped. In time with this, the supplying roller, regulating roller and cleaning roller are kept on rotating for a predetermined period while the bias voltages are switched so that the direction of the electric fields acting on the toner, formed between the rollers after switching are opposite to those formed during development.

Image developing device using a toner as a developer

A cleaning element is arranged on the backside of the toner layer metering blade, i.e., the side opposite to the surface in contact with the developer support, in order to prevent the cleaning element from damaging the blade surface and the abutment surface of the metering blade against the developer support. This cleaning element is frictionally moved across the backside of the toner layer metering blade to remove stuck toner from the toner layer metering blade or prevent occurrence of buildups.

Developer unit with cleaning element

Image forming apparatus realizing stable charging and development characteristics

The image forming portion of this image forming apparatus includes a LSU, a photosensitive drum, a developing unit holder, a multiple number of developing units, an intermediate transfer element, a transfer element and a fixing unit. All the developing units are of an identical configuration. Therefore, for replacement of developing units, the operator may and should remove any color of developing unit in the same fashion and attach a fresh developing unit of the color in the same fashion. The image forming portion sets up the image forming conditions for individual colors in the developing order.

Image forming apparatus

A contact charging device includes a charging roller and a power source, the charging roller having a conductive core, a conductive elastic layer and a coating layer and rotating as being in contact with a photoreceptor drum made up of a conductive body and a photoconductor, and the power source applying between the core and the body a bias voltage in which an ac voltage has been superimposed on a dc voltage. The charging roller and the photoreceptor drum form an oscillation system of a characteristic frequency fm which oscillates due to static adsorptive force. The characteristic frequency fm is calculated from each parameter of the oscillation system, and a frequency fac of a superimposed ac voltage or twice the value of the frequency fac is set to fall within a range of fac&lE;0.5 fm or fac&gE;1.5 fm so as to suppress both resonance of the oscillation system and relatively large oscillation when taking viscosity damping resistance into consideration. A highly reliable contact charging device capable of surely preventing charging noise can be provided by adopting the highly universal condition of suppressing oscillation as obtained by an efficient method.

Contact charging device, process cartridge and image forming device having the same

In a mono component toner developing device, a developing roller supporting and conveying the mono component toner is arranged in contact with a photoreceptor supporting a static latent image. A supplying roller is arranged opposing the developing roller with a predetermined contact depth. The supplying roller has a pair of driven gears fixed at both ends of the rotational shaft thereof for being rotated so as to be meshed with a pair of driving gears rotated by a driving motor. The rotational force of the driving gears, acting at a coupling position, is used to deflect the supplying roller toward the developing roller side, whereby the supplying roller is pressed in approximately uniform contact with the developing roller across its full length along the shaft.

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Nara, Japan

Atsushi Inoue