Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

International Business Machines Corporation

Shindengen Electric Manufacturing Company Limited

Kabushiki Kaisha Tec

Yamanashi Electronics Co., Ltd.

Michihisa Iguchi

Seiji Arai

Tetsuya Nakamura

Takahito Kabai

Satoshi Katagata

Chinobu Sakai

Hiroshi Hashizume

Hirotaka Fukuyama

Masaaki Ishikawa

Yoshiaki Okano

Kouichirou Satou

Takashi Ishikawa

Koichiro Sato

Toshio Takagi

Yasuo Fujii

Yukio Tsuda

Seiichi Koizumi

Jiro Hukasawa

Hideya Ino

Jinichi Satoh

Shuji Nishina

Masatoshi Maruta

At start of rotation of a photosensitive drum, rotation of a developing roller caused by a developing/register rollers driver is kept stopped until a time required for a predetermined point on the photosensitive member, which was located at a charging position when charging thereof by a charging device was started, to reach a development position elapses, and thereafter the developing roller is rotated by the developing/register rollers driver. When the predetermined point on the photosensitive member, which was located at the developing position when at least rotation of the photosensitive member was started, passes the transfer position, a roller cleaning voltage having the same polarity as the charge polarity of toner is applied to a transfer roller.

Electrophotographic apparatus that prevents toner from attaching to a

A developing device used in an electrophotographic apparatus has seal members fixedly disposed between both end portions of a developing roller and those portions of inner walls of a device casing which correspond to both end portions of the developing roller. The seal members are made of a material which can be charged by friction with the developing roller to have the same polarity as charged toner. The toner is blocked by the seal members and presented from entering end portions of the developing roller.

Electrophotographic apparatus having cleaning device and developing

In a developing device for developing an electrostatic latent image formed on a photosensitive member in an electrophotographic apparatus, a developing roller and a developing blade are formed such that the hardness of the surface of the developing blade is higher than the hardness of the surface of the developing roller by 30 degrees or more in JIS-A hardness. The developing blade deforms and bites into the developing roller. Accordingly, the developing roller can be brought into tight contact with the developing blade, and a great frictional force is applied to the toner passing between the developing roller and blade to fully charge the toner.

Developing device for electrophotographic apparatus

In a recording apparatus for performing electro-static recording using toner, an image forming apparatus has a process unit including, as one unit, at least a photosensitive member and a spent toner holding section, a first counter for counting a total amount of use of the photosensitive member and a second counter for counting a total amount of toner that has been consumed. A determining section using the process unit determines the necessity for the process unit to be replaced with a new process unit by comparing a total amount of use of the photosensitive member counted by the first counter with a first predetermined reference value and the total amount of consumed toner with a second predetermined reference reference value according to whether the total amount of use of the photosensitive member exceeds the first reference value or the total amount of toner counted exceeds the second reference value.

Image forming apparatus using a process unit

A transfer device of a contact transfer method wherein a transfer power supply applies a predetermined transfer voltage to a transfer roller contacting the rear surface of a printing sheet, so that an electric field for causing the toner to be attracted by the transfer roller is generated. A lumped constant resistor is electrically inserted between the transfer roller and the transfer power supply. The lumped constant resistor has an electric resistance smaller than an equivalent electric resistance obtained when the whole transfer roller is regarded as one electric resistor. When the electric resistance of the printing sheet changes in accordance with a change in ambient environment, the voltage drop across the lumped constant resistor is changed to compensate for the change in electric resistance of the printing sheet.

Transfer roller and toner for electrophotographic apparatus

An image forming apparatus includes a distributing device for distributing residual toner remaining on a photosensitive member after a developed toner image is transferred to a sheet-like paper and before a subsequent image is formed. The distributing device includes a distributing brush which is located between a transferring device and a charging device, has a contact portion contacting the photosensitive member, and includes a voltage supply device for supplying a direct current voltage to the distributing brush. The voltage difference between the distributing brush and the photosensitive member is sufficient to cause a discharge to occur between the distributing brush and photosensitive member.

Image forming apparatus

A developing device used in an electrophotographic apparatus has seal members fixedly disposed between both end portions of a developing roller and those portions of inner walls of a device casing which correspond to both end portions of the developing roller. The seal members are made of a material which can be charged by friction with the developing roller to have the same polarity as charged toner. The toner is blocked by the seal members and prevented from entering end portions of the developing roller.

Electrophotographic apparatus having developing device with seals for

In an electrophotographic device, a main body is divided into a lower body and a swingable upper body. A process unit formed of at least a toner holder, a charger, and a developer is detachably mounted in the lower body. The position of the process unit (particularly, the photosensitive member) relative to the lower body (particularly, a member driving gear) is controlled by placing a shaft of the member through a groove in a side wall of the lower body at one end of the member, and by bringing a lower end of the side wall of the process unit supporting the member into contact with an upper end of a support member supporting the member driving gear. An exposure unit mounted in the upper body is positioned to the photosensitive member with a predetermined distance therebetween by bringing a contact portion of the exposure head into contact with the side wall of the lower body supporting the member.

Detachable process unit for an electrophotographic device

A developing device includes an agitator rotated in a toner hopper. The agitator has a rod portion. A first coil spring portion is wound around the first portion of the rod portion in a first direction. A second coil spring portion is wound around the second portion of the rod portion in a second direction. The first direction is opposite to the second direction.

Developing device and image forming apparatus including an agitator

A toner pack for use in an electrophotographic apparatus is formed of a polypropylene resin containing 30 to 50 wt % calcium carbonate filler. This resin has a high deformability, and generates a small amount of heat at the time of incineration thereof. Thus, the used toner pack can be disposed of together with flammable products made of paper and/or wood. Further, at the time of disposal, it is possible to fold the used toner pack to reduce its size.

Toner pack and development device for use in electrophotographic

A developing apparatus including a hopper storing toner and carrier and a roller disposed in an opening of the hopper. A carrier stopper is provided on a front wall of the hopper proximate the opening having an arced surface concentrically opposing an upper portion of the roller. Thus, a blend layer volume is formed in a first space between the carrier stopper and the roller for storing a blended layer of carrier and toner such that the carrier stopper prevents carrier from scattering outside the blend layer volume and the conjunctional effect of rotating the roller and of the magnetic force of the rotary magnets in the roller blends the carrier and toner stored in the blended layer. A sub-hopper, proximate the blend layer volume, is also formed by a second space between the carrier stopper and a lateral bottom wall of the hopper for storing toner to be provided to the blended layer.

Developing apparatus

An improved automatic paper feeding device for a facsimile equipment or the like apparatus is disclosed which includes a feeding roller (3) disposed below the feeding end part of an inclined paper feeding board (2) and a reversing roller (7) located above the feeding roller (2) in a line contact relation to be rotated in the opposite direction to that of drawing of papers from the paper feeding board (2), the reversing roller being rotatably supported at the free end part of side plate members (20) adapted to turn about a support shaft (21). A connecting line between the shafts (4,8) of the feeding roller (7) and the reversing roller (7) extends substantially at a right angle relative to a connecting line between the shaft (8) of the reversing roller (7) and the support shaft (21) for the side plate members (20). The direction of tension given by an endless belt (36) for rotating the reversing roller (7) is selectively determined to extend substantially at a right angle relative to the connecting line between the shafts (4,8) of the feeding roller (3) and the reversing roller (7) whereby contact pressure to be exerted on the feeding roller (3) by the tension of the endless belt (36) via the reversing roller (7) becomes practically zero. Thus it is assured that the device is operated without any extra contact pressure active on the feeding roller while fluctuation in contact force is minimized.

Automatic paper feeding device for a facsimile equipment or the like

A sheet feeding apparatus that can be adjusted to feed various sized sheets includes a fixed paper guide and an adjustable paper guide. A roller in cooperation with a limiting element insures that only a single sheet is drawn from a stack. To prevent uneven feeding and wrinkling, the center of the roller is biased toward the fixed guide from the medial line between the guides when they are separated by a maximum distance. Preferably, the length of the limiting element is shorter than the length of the roller, and when the guides are separated by a maximum distance the medial line between the guides falls along an edge of the limiting means.

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Tokyo, Japan

Michihisa Iguchi