Casio Electronics Manufacturing Co., Ltd.

Casio Computer Co., Ltd.

Casio Computerco., Ltd.

Takao Yorifuji

Noriki Ono

Moriyuki Kouroku

Tatsumi Shimanari

Yoshiharu Abe

Toshihiko Numazu

Tetsuya Abe

Masatoshi Maruyama

Hidefumi Kanai

Mitsugu Oishi

Takeo Hirono

Mitsuo Hayashi

Masaki Kanasugi

Yasushi Nakamura

Photosensitive drum casing for an electronic copying machine

A developing device used in an image forming apparatus has a developing roller at a lower opening of a toner hopper, and the developing roller contacts a photosensitive drum to form a developing portion therebetween. The hopper stores nonmagnetic toner and is provided with a toner stirring member and a toner feed roller being in press-contact with the developing roller in a lower part of the hopper. A doctor blade contacts a circumferential surface of the developing roller on an upstream side of the developing portion in a rotation direction of the drum. A conductive scooping sheet contacts the circumferential surface of the developing roller on a downstream side of the developing portion. A residual toner not used to develop a latent image on the drum and left on the developing roller is passed under the sheet into the hopper with the rotation of the developing roller. A sheet bias voltage ranging from 0V to -250V is applied to the sheet, so that an attaching force of the residual toner to the developing roller is weakened so that the residual toner can be easily removed by the feed roller.

Developing device, image forming unit and color image forming apparatus,

A roller-shaped contact charging member which is in contact with and electrically charges a photosensitive drum is provided on a center shaft, and includes a roller-shaped conductive foam material portion covering the shaft, and a tubular-shaped conductive resin material portion covering the foam portion. The foam portion has an electric resistance of 9.times.10.sup.5 .OMEGA. or less, the resin portion includes conductive agents and has a surface electric resistance in a range from 1.times.10.sup.5 .OMEGA./.quadrature. or more to 9.times.10.sup.7 .OMEGA./.quadrature. or less, and a hardness of the charging roller as a whole is Asker F 90.degree. or less. An image forming unit includes the charging member and the drum. An electrophotographic image forming apparatus supplies a recording paper to the unit, transfers an image from the drum to the paper, and discharges the image-transferred paper.

Contact charging member, image forming unit including the contact

A motor starts its rotation, and a clutch is operated to drive both of a first driving force transmission system for color printing, including drum gears, and a second driving force transmission system for monochrome printing, including a drum gear. The clutch is disengaged to stop the first system when a first sensor detects a mark on one photosensitive drum of the first system at the same time that a second sensor detects a mark on one drum driving gear of the first system. Next, when a third sensor detects a mark on another photosensitive drum of the second system at the same time that a fourth sensor detects a mark on another drum driving gear of the second system, the clutch is reengaged. Consequently, positionings of all the photosensitive body drums (drum gears) for color printing to the photosensitive drum (drum gear) for monochrome printing are performed without causing positional differences by inertia at the time of stop.

Image forming apparatus and image forming unit with an improved phase

An image forming apparatus has four color image forming and transferring portions and four image writing heads supported by a cover to be rotatably movable upwardly and downwardly. Each case of the portions is so shaped that it does not interfere with the rotational movement of the heads, and has the same shape. Particularly, two opposite side surfaces of the case is so shaped that it does not project into the movement locuses of the heads not to collide them.

Image forming apparatus for color image forming

A toner collector includes a tube having at least one opening in an intermediate portion between both end portions, one of the both end portions being closed, a toner collecting bag covering the tube, and connected to the tube at the both end portions of the tube, and a waste toner transfer member, connected to the other of the both end portions of the tube, for transferring toner to the other of the both end portions from an outer side of the tube. An image forming unit, which is combined with an image carrier on which an image to be developed by toner is formed, and a cleaner for removing unnecessary toner from the image carrier to make an image forming apparatus so that the image on the image carrier is developed by toner, includes a developing unit for developing the image on the image carrier by toner, a toner hopper having a toner containing space, for supplying toner to the developing unit, a tube provided in the toner containing space of the toner hopper, having at least one opening in an intermediate area between the both end portions, one of the both end portions being closed, a toner collecting bag covering the tube and connected to the tube at the both end portions of the tube, and a waste toner transfer member, connected to the other of the both end portions, for transferring unnecessary toner to the other of the both end portions of the tube from the cleaner.

Toner collector and image forming unit having toner collector bag

A developer circular unit is detachably set in a copier or a copier type printer which print on images on a paper sheet with toner. The unit includes at least a developing device, a cleaner, and a developer conveying device having a pipe communicated with both the cleaner and the developing device and a toner flowing-back preventing mechanism. The action of the mechanism is automatically released by the first set of the unit in the copier or printer and/or the first use of the copier or printer after that first set.

Developer restoring unit in an image forming apparatus

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Higashiyamato, Japan

Takao Yorifuji