Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Eiichi Sano

Masahiro Anno

Junji Machida

Junji Ohtani

Masahiko Matsuura

Makoto Kobayashi

Masahide Ueda

Masami Yamada

Shoichi Minato

Atsuto Hirai

Tomoo Izumi

Toshitaro Kohri

Yoshihisa Terasaka

Hiroyuki Yamasaki

Fumio Masuda

Yasuhiro Ohno

Ken Tanino

Kazuo Ota

Masami Miyazaki

Hiroshi Mizuno

Izumi Osawa

Shuji Iino

Toshiya Natsuhara

Makoto Fujii

Yoshihiro Fukuhata

Kouichi Etou

Yukio Tanigami

Satoshi Yoshida

Kazuo Mohri

Shoukou Gon

An ink jet printer ejects ink droplets of a plurality of sizes based on image data, and prints dots of a plurality of sizes corresponding to the ink droplets of the plurality of sizes for recording the image. In the ink jet printer, in order to print a smoothing dot close to a normal dot, pulse voltage having a waveform having its printing timing changed from a waveform for printing the normal dot is applied to a piezoelectric element. As a result, an ink jet printer capable of recording high definition images can be provided.

Ink jet printer capable of forming high definition images

A heat fixing device for heat fixing a toner image to a receiving medium having a pair of fixing belts in an endless form; a pair of rotary members individually disposed on a respective inside circumference of the fixing belts and pressed against each other via the fixing belts; a pair of fixing members individually disposed on the respective inside circumference of the fixing belts and pressed against each other via the fixing belts; and a heating element for heating at least one of the fixing belts, wherein the fixing belts contact the rotary members and the fixing members only at a respective portion thereof via which the respective pair of rotary members and fixing members are pressed against each other.

Heat fixing device and image forming apparatus

The fixing device of the present invention comprises a heating roller having an internal heating device; a flexible fixing belt wrapped around the exterior side of the heating roller and having a circumferential length longer than the circumferential length of the heating roller; and a pressure roller for pressing against the heating roller through the fixing belt, wherein a slack part of the fixing belt is formed on the downstream side from the pressure contact part between the heating roller and the pressure roller in the direction of transport of the recording medium, such that this slack part touches the exterior surface of the pressure roller.

Fixing device provided with a fixing belt

An ink jet printer is adapted to drive a piezoelectric element by applying pulse voltage having waveforms of A,-A,based on image data, fly ink drops respectively having sizes corresponding to waveforms A,-A,of the pulse voltage, and record an image on a recording sheet. In the ink jet printer, a rise rate of pulse voltage having waveforms A,-A,corresponding to ink drops of relatively small sizes is set such that the rise rate is high compared with that of pulse voltage having waveforms A,-A

Ink jet printer outputting high quality image and method of using same

A detecting device includes a first electrode 42, a second electrode 44, and a conductive portion 14 mounted on a belt 12, for detecting a transverse movement of the belt 12. The electrodes 42 and 44 cooperate with the conductive portion 14 to form a contact-type switch, or mechanical switch. When the belt 12 moves from a first region 46 to a second region 48, the conductive portion 14 comes into contact with the electrodes 42 and 44 to close the switch. A control unit 50 detects an output from the switch. When the control unit 50 has detected a change of the output signal, it causes a correcting mechanism 24 to energize, thereby returning the belt to the first region.

Apparatus for detecting a transverse movement of an endless belt

A belt slippage correcting device and method for correcting slippage of a belt which is transported in a predetermined direction. The belt slippage correcting device has a slippage detecting device for detecting slippage of the belt in a direction perpendicular to the belt transporting direction and a moving device for moving the belt in the direction perpendicular to the belt transporting direction and control device for controlling the moving device based on the detected slippage of the belt by the belt slippage detecting device The slippage of the belt is corrected while the moving velocity of the belt in the direction perpendicular to the belt transporting direction is maintained within a predetermined scope of velocity. The device and method may be used in an image forming apparatus, such as an electrophotographic image forming apparatus.

Belt slippage correcting device which controls movement of the belt in a

A fixing device includes a heater and a fixing belt entrained around first and second supporting rollers. A pressure roller is arranged outside the belt. Also, an elastic forcing member is arranged inside the belt to force a portion of the belt running between the two supporting rollers against the pressure roller so that the belt portion is brought into circumferential contact with the pressure roller to form an extended nipping region. In addition, a braking device connected to an upstream support roller stretches the belt at the nip region. With this arrangement enough amount of heat is supplied to a recording medium and toner image flattening is prevented.

Fixing device with endless belt

A belt-type fixing device includes a rotatably supported endless belt and a outer roller arranged outside the belt in contact therewith. Arranged inside the belt are a heater and an inner roller which are forced at respective pressures to the outer roller through the belt. Pressure of the inner roller to the outer roller is adjusted to be greater than that of the heater to the outer roller.

Belt-type fixing device

An image forming apparatus having a charger which applies a voltage of the same polarity as a toner image formed on an intermediate transfer member onto an upstream side of a first transfer portion at which the intermediate transfer member faces an image bearing member, as well as a transfer electrode which applies a bias voltage of an opposite polarity to the toner image onto a downstream side of the first transfer portion. On an upstream side of a second transfer portion at which the toner image formed on the intermediate transfer member is transferred by a transfer roller onto a transfer sheet with respect to a sheet transporting direction, a bias voltage applying device is provided which applies to the transfer sheet a voltage of an opposite polarity to the toner image and greater than a surface potential of the intermediate transfer member at the second transfer portion. At a position facing to the transfer roller through the intermediate transfer member, a voltage of an opposite polarity to the toner image is applied, and a recharger is provided which applies to the intermediate transfer member a voltage of the same polarity as the toner image on an upstream side of the second transfer portion.

Image forming apparatus including toner scattering prevention

An image forming apparatus includes a first developing device, accommodating a first kind of toner without an offset preventing agent, a second developing device accommodating a second kind of toner containing an offset preventing agent, and a roller fixing device having a supply portion for supplying an offset preventing agent. The image forming apparatus changes the amount of the offset preventing agent to be supplied to the fixing roller between the case of fixing a copy image formed with the first kind of toner and the case of fixing a copy image formed with the second kind of toner.

Image forming apparatus provided with mold releasing agent coating

A fixing device includes a rotatably supported endless belt and a nip forming member arranged outside the belt in circumferential contact therewith to form a nipping region. Heat generators are arranged adjacent the nipping region. Each heat generator is extended in a transverse direction of the belt, and spaced apart a certain distance from the neighboring one. A controller controls the heat generators so that a temperature of the belt heated by one of heating means is maintained until a subsequent heating.

Fixing device with endless belt and plural heaters

An image forming apparatus for forming an image onto a sheet includes a sheet supporting member; a charger which is positioned in a vicinity of the sheet supporting member; and a device for controlling the charger so that the charger charges a specific portion of the sheet supporting member corresponding to a leading edge portion of the sheet to an electrostatic potential higher than that of a remaining portion of the sheet supporting member. A method of adhering a sheet to a sheet supporting member during an image forming process includes charging a specific portion of the sheet supporting member corresponding to a leading edge portion of the sheet to a first electrostatic potential; charging a remaining portion of the sheet supporting member to a second electrostatic potential that is lower than the first electrostatic potential; and delivering the sheet to the sheet supporting member so that a leading edge portion of the sheet is aligned with the specific portion of the sheet supporting member.

Image forming apparatus including an endless transfer member

The present invention relates to a method of producing a plurality sets of prints from a plural-page original in an image forming apparatus having an endless transfer member onto which images are transferred from an image retaining member. The endless transfer member is operable to support a predetermined number (X) of images during one cyclic movement thereof. In this method, a first printing operation is executed in which the predetermined number (X) of images of a first page of the original are formed on the endless transfer member during one cyclic movement thereof when a desired number (Y) of sets of prints exceeds said predetermined number (X). Second, the first printing operation is repeated until a remaining number (M) of image(s) of the first page becomes less than said predetermined number (X). Third, a second printing operation is executed in which the remaining number (M) of image(s) of the first page and a calculated number (X-M) of image(s) of a second page of the original are formed on said endless transfer member during one cyclic movement thereof after the remaining number (M) of image(s) of the first page becomes less than the predetermined number (X).

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Takatsuki, Japan

Eiichi Sano