Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Ricoh Printing Systems, Ltd.

Hitachi Printing Solutions, Ltd.

Tadahiro Kaneko

Takao Umeda

Shigenori Yaguchi

Masayasu Anzai

Nobuyoshi Hoshi

Tsuneaki Kawanishi

Ryuuichi Shimizu

Junji Kobayashi

Katsuhiko Suzuki

Ryoji Kojima

Michio Yokosuka

Teruaki Mitsuya

Tsutomu Maekawa

Nobuhiro Noto

Osamu Kawanobe

Yo Kawakami

Satsuo Sato

Hiroyasu Ishikawa

Takeshi Toyoshima

Takao Abe

Juurou Kobayahsi

Takayoshi Kaneta

An electrophotographic toner containing: a fixing resin, a colorant, and wax. The wax at least contains hydrocarbon wax having a number-average molecular weight of not higher than 600, and polyethylene wax having a number-average molecular weight of not higher than 600, a melting viscosity of lower than 15 mPa&#xb7;s at 140&#xb0; C. and a crystallinity of lower than 95%. A ratio of the hydrocarbon wax to the polyethylene wax is in a range of from 1:10 to 2:1. A maximum of absorption peaks in a heat-up time absorption calorie curve in a DSC curve of the toner measured by a differential scanning calorimeter is at a temperature not higher than 75&#xb0; C. An onset temperature in absorption of heat is not higher than 65&#xb0; C.

Electrophotographic toner and image-forming system

Electrostatic image developing toner includes fixing resin; and wax. The wax is hydrocarbon-based wax. The wax is containing, as its constitutional components, first wax and second wax. The first wax is higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa&middot;s in melt viscosity at 140&deg; C. and higher than 75% and not higher than 85% in degree of crystallinity. The second wax is not higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa&middot;s in melt viscosity at 140&deg; C. and higher than 85% and not higher than 95% in degree of crystallinity.

Electrostatic image developing toner and image forming method

A fixing system for fixing toner images onto an image printing system such that the image printing medium bearing the toner images on the obverse side and the reverse sides thereof is passed through a nip area between a pair of fixing rollers. In the nip area, a rotation speed of a first fixing roller, which comes into contact with a not-yet fixed toner image, which is formed on the obverse side of the image printing medium, is set to be substantially equal to a rotation speed of a second fixing roller, which comes in contact with a not-yet fixed toner image, formed on the reverse side of the image printing medium. This is accomplished by setting the diameters of the various layers of the first fixing roller to be equal to that of the second fixing roller. When the image printing medium is moved through the nip area by the fixing rollers, a moving speed of the upper side of the image printing medium is equal to that of the lower side thereof. Thus, stresses on the image printing medium are not caused, and no character blur takes place.

Apparatus for printing on both sides of an image printing medium by one

In an electrostatic both-side printing system, a first image forming unit is provided upstream of an image printing medium when viewed in the transporting direction of the image printing medium, and a second image forming unit is provided downstream of the image printing medium. A medium transporting path for transporting the image printing medium is formed between the first and the second image forming units. A first transferring unit, located facing the first image forming unit with the medium transporting path intervening therebetween, for applying no charge onto the rear side of the image printing medium, which does not face the first image forming unit. A second transferring unit being located facing the second image forming unit with the image printing medium with the medium transporting path intervening therebetween, in a state that the second transferring unit is apart from a first toner image formed on the image printing medium by the first image forming unit. In the both-side printing system thus constructed, the first and the second image forming units, and the first and the second transferring units cooperate to form first and second toner images on both sides of the image printing medium, the first and the second toner images being opposite in polarity.

Apparatus for printing images on both sides of an image printing medium

A fixing unit includes a fixing roller, a pressure roller forming a nipper in cooperation with said fixing roller, the nipper conveying a recording material on which an unfixed image is formed while nipping the recording material, a recording material pressing roller disposed at least one of upstream and downstream of said nipper in a recording material conveyance direction for pressing said recording material toward the fixing roller to form a region where the recording material is wound around the fixing roller, and a tension applying unit for applying tension to the recording material.

High-speed electrophotographic fixing unit

A grinder has a grinding member. The grinder includes a rotatable spindle having an engagement portion. A first flange engages the engagement portion of the spindle. The first flange and the engagement portion of the spindle define a given play therebetween in a direction of rotation. The grinding member is held between the first flange and a second flange. A lubricant solid material is provided between the first flange and the engagement portion of the spindle.

Portable grinder

Growing community of inventors

Ibaraki, Japan

Tadahiro Kaneko