Fujitsu Corporation

Yoshio Yamaguchi

Akira Nagahara

Takefumi Takahashi

Nobuo Kuwabara

Sachio Sasaki

Toshio Tooda

Haruyasu Watanabe

Mitsuru Sato

Shigenobu Utaka

Hiroshi Kera

Mitsuhito Furukawa

Hisashi Hanzawa

Yoshiya Ishiyama

Yoshihiro Watanabe

Tetsuya Takei

Yoshiya Matsumoto

Masahiro Wanou

Nobuyuki Tanaka

Takeo Kojima

Hideki Kamaji

Shigeo Nonoyama

Fumihiro Itoh

Shinzo Tanaka

Shizuo Takano

Masanori Nishido

Mituru Sato

To provide an electrophotography apparatus with which the service life management of a printing unit can be carried out properly, a non-volatile memory for storing a count value for managing the service life of the printing unit is installed in both a main unit and the printing unit of the electrophotography apparatus. Then, the count value is written to the memory on the printing unit (PU) side (PU memory) when print processing is not in progress, and no power is supplied to the PU memory during print processing, so the correct count value is always stored in the PU memory. Therefore, the service life of the printing unit can be correctly evaluated.

Electrophotography apparatus

An image forming device includes an image forming part which forms an image on a recording medium; a recording medium switchback portion which receives the recording medium on a first run, one side of which has been printed when passing the image forming part, and sends the recording medium for a second run; a recording medium path which communicates with the recording medium switchback portion so as to send the recording medium to and from the recording medium switchback portion; an inverted recording medium transfer path through which the recording medium is sent to the image forming part again with an upper surface and a lower surface of the recording medium reversed; and a recording medium transfer part which transfers the recording medium along the inverted recording medium transfer path. The image forming device is further provided with a first recording medium receiving portion which stores the recording medium one on another with a printed surface facing upwards; and a first recording medium ejection path which communicates with the recording medium receiving portion so as to send the recording medium to the first recording medium receiving portion.

Image forming device

An electrophotographic image forming apparatus including a toner circulating mechanism for recovering a residual toner scraped from a photosensitive drum to a developing device. The developing device includes a housing for defining a toner chamber, a developing roller rotatably mounted in the housing, an agitator rotatably mounted in the housing and provided in the toner chamber, and a partition member mounted to the housing to define a carrier chamber between the partition member and the developing roller. The toner circulating mechanism directly returns the residual toner scraped from the photosensitive drum to the toner chamber in the developing device. The toner chamber may contain a foreign matter removing device. The partition member may have various shapes.

Electrophotographic image forming apparatus having a device for

An electrophotographic image forming apparatus includes an electrostatic latent image carrying body, an electrifying unit for electrifying the image carrying body, a light irradiating unit to form an electrostatic latent image in accordance to image information, a developing unit for discharging toner to the image carrying body to develop the latent image, a transfer unit for transferring the toner image to a recording sheet, and a cleaner for removing residual toner on the image carrying body. The toner removed from the image carrying body is recirculated to the developer receiving box. An additional toner image is formed on a position other than a first position where the electrostatic latent image is formed in accordance with the image information. The toner is removed by the cleaner without being transferred to the recording sheet and recirculated from the image carrying body to the developer receiving box.

Electrophotographic image-forming apparatus with uniform toner usage

A developing apparatus is provided for developing an electrostatic latent image on a latent image carrier by supplying the latent image carrier with a developer. This developing apparatus includes a toner accommodating chamber for accommodating magnetic toners. The apparatus also includes a developing roller, having a plurality of fixed magnetic pole members and sleeves provided along peripheries of the fixed magnetic pole members and rotating thereabout, for feeding the developer composed of magnetic carriers and magnetic toners to the latent image carrier. The apparatus further includes a developing chamber having a partition wall formed along the developing roller and assuming a configuration adapted to a shape of the developing roller, and a toner supply port for supplying the magnetic toners to the developing chamber from the toner accommodating chamber. In another mode of the developing apparatus, the center of each magnetic pole of the fixed magnetic pole members is located in a position deviating from the toner supply port. Further, in still another mode of the developing apparatus, there is employed the magnetic carrier the core of which is iron powder exhibiting strong saturation magnetization.

Developing unit having improved toner density control

An image forming apparatus which collects residual toners on a latent image carrier in a developing unit. The image forming apparatus have a rotary endless latent image carrier; an image forming unit for forming an electrostatic latent image on the latent image carrier; a developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer and collecting residual toners on the latent image carrier at a same time; a transfer unit for transferring the developed image on the latent image carrier onto a sheet; a distribution member for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer; and a voltage supplying unit for supplying an AC voltage to the distribution member. An image forming apparatus according to another aspect have a rotary endless latent image carrier; an image forming unit for forming an electrostatic latent image on the latent image carrier; a developing unit for developing the electrostatic latent image on the latent image carrier with a powdery developer and collecting residual toners on the latent image carrier at a same time; a transfer unit for transferring the developed image on the latent image carrier onto a sheet; and a distribution roller for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer.

Image forming apparatus for collecting residual toner from a drum using

An image forming apparatus for forming an image on a sheet, including a rotary endless latent image carrier, an image forming device for forming an electrostatic latent image on a latent image carrier, a developing device for developing the electrostatic latent image on the latent image carrier with powdery developers and collecting residual toners on the latent image carrier at the same time, a transfer device for transferring a developed image on the latent image carrier onto a sheet, a distribution roller having independent foam perforations for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer, and a power supply for supplying an AC voltage to the distribution member. The distribution member is made of a conductive foam member having a pore at a surface contacting with the latent image carrier and the roller rotates in a direction opposite to a rotational direction of the latent image carrier at a peripheral velocity of 1.1 to 1.5 times that of the latent image carrier.

The present invention relates to an image forming device such as a copying machine, a printer, or the like that records an image on a sheet of ordinary paper, more particularly to image forming device that can be installed in multiple direction, for example, vertically or horizontally. The object is to realize a device serviceable to any installation direction and to provide a stable operation independently on the installation direction and an improved reliability. The image forming device consists of an installation direction detecting unit for detecting an installation direction of the device body; and a control unit for controlling the operation of the device body according to the installation direction detected. The control unit includes the plural control sequence units each arranged in an installation direction for setting a control condition corresponding to the installation direction, and a control condition selecting unit for selecting a control sequence unit corresponding to the installation direction detected among the plural control sequence units.

Disclosed are a toner empty detecting method of and a toner empty detecting apparatus for detecting an empty state of toners in a toner hopper. The toner empty detecting method comprises: a step of taking in the output of the detecting element with every constant period; a step of comparing a detected value relative to a take-in value with an average value of the detected values during a detection period of last time; a step of counting the number of times when the detected value is smaller than the average value during a detection cycle of this time; and a step of generating a toner empty output when the count value is larger than the predetermined value. The toner empty detecting apparatus comprises: a toner sensor for detecting the toners in the toner hopper; and a control circuit for comparing a detected value relative to a take-in value when taking in an output of the toner sensor with every constant period with an average value of the detected values during a detection period of last time, comparing the count value with a predetermined value and generating an empty output when the count value is larger than the predetermined value. Even if there is a scatter in output level of the toner detection sensor, the toner empty can be thereby stably detected.

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Kawasaki, Japan

Yoshio Yamaguchi