Hitachi, Ltd.

Ricoh Printing Systems, Ltd.

Hitachi Prinitng Solutions, Inc.

Kazuo Kikuchi

Tetsuji Takegoshi

Kazuhiro Wakamatsu

Toshio Ogiso

Chikara Hiraoka

Shunichi Oohara

Masaru Nakano

Toru Hanashima

Masahiko Saito

Masashi Yamamoto

Shogo Matsumoto

Atsushi Onose

Hiromitsu Fukuda

Noriyoshi Ogura

Shoji Ukei

Katsuyoshi Onose

Akira Shimizu

Hiroyuki Seki

Akira Sasaki

Yoshiaki Yamauchi

Takashi Yamamoto

Tadashi Okano

Taisuke Kashima

Akira Shimada

Shigeru Obata

Hiroshi Kanai

Katsumi Kumada

Seiichi Hayashi

Takamitsu Ikematsu

Seiji Okunomiya

Yousuke Nagano

Yukio Kuroiwa

Masayoshi Sunada

Kazushige Oonishi

Takeo Sonobe

Satoshi Narita

Yoshifumi Homma

Hitoshi Ishida

Junichi Shoji

Junichi Enomoto

Yuuichi Takano

Takashi Kakuhashi

Hitoshi Furuyama

Yasumasa Saito

Toshiaki Suematsu

Tetsuro Hatakeyama

Shinji Mizunuma

Tuyoshi Koyama

Kazuei Saito

Toru Ohashi

Tsuyoshi Koyama

A paper feeder is capable of minimizing abnormal noise produced at a separation pad during paper feed, without reducing the paper feed capability, for use in an image forming apparatus using the same. Buffers are mounted on the separation pad. This arrangement ensures that, when a stick-slip condition occurs between the paper and separation pad during paper feed, and the separation pad is vibrated by the paper, the buffer vibrates so as to dissipate the vibration energy of the separation pad, with the result that the vibration of the separation pad is minimized, thereby to reduce any abnormal noise.

Paper feeder with separation pad and vibration buffers

A fixing device includes a roller; an endless belt which is in contact with the roller and rotates with a circulation of the roller in a follower manner; a heating source in at lease one of an inside of the roller and an inside of the endless belt; and a pressure-applying member which is inside the endless belt and presses the endless belt against the roller. A sliding layer is provided on a side on which the pressure-applying member is in contact with the endless belt, and the sliding layer comprises at least two layers and holds a lubricant.

Fixing device and image forming apparatus

An image forming and recording apparatus, having a fixing apparatus for fixing unfixed toner image on a recording medium, wherein the fixing apparatus includes a fixing roller integrating a heater therein, an endless belt wound around the fixing roller, and three pressure members for pressing the endless belt onto the fixing roller. A pressure member located nearest to a side of entry of paper among the three pressure members is made up with a non-rotary type pressure member, and other two pressure members are made up with either one of a rotary type pressure member and the non-rotary type pressure member.

Image forming and recording apparatus with three pressure members

An image forming apparatus includes a photosensitive belt carried by a driver device, for forming a toner image thereon; an internal transcription belt for transcribing the toner image; and a transcription portion for transcribing the toner image, which is transcribed on the internal transcription belt, onto a recording medium. A transcription side roller is suspended with the internal transcription belt thereon, and disposed on a side of a photosensitive belt side roller. Detectors detect a first cycle of the internal transcription belt, and a second cycle, which starts measurement delaying by &#xbd; cycle of the photosensitive belt side roller from the first cycle measurement start. A controller conducts speed compensation of the photosensitive belt by referring to the first cycle and the second cycle, wherein the internal transcription belt is in contact with the photosensitive belt, so that it is carried following thereafter.

Image forming apparatus for conducting speed compensation by internal transcription belt cycle measurement

A picture image forming apparatus including a photoreceptor belt driven by a drive device, a plurality of developing devices for forming toner picture images on the photoreceptor belt, an intermediate transfer device, to a surface of which toner picture images on the photoreceptor belt are overlappingly transferred plural times when a picture image is to be formed on a single page, and a transfer roller for pushing a sheet against the intermediate transfer device in order to transfer toner picture images to the sheet. The intermediate transfer device is an intermediate transfer belt contacted by the photoreceptor belt to be driven thereby. A photoreceptor-side roller enables contact of the intermediate transfer belt and the photoreceptor belt, and the intermediate transfer belt is trained around the photoreceptor-side roller and a transfer-side roller for pushing the sheet against the transfer roller. A diameter d2 of the transfer-side roller is smaller than a diameter d1 of the photoreceptor-side roller.

Picture image forming apparatus with intermediate transfer belt trained around two rollers of different diameter

A fixing device in an image formation apparatus has a heating roller and a backup roller. These rollers are each coated with single silicone rubber layers around the respective peripheries of their core bars. This silicone rubber has a volume resistance value of 10 &OHgr;&middot;cm or more. The heating roller is charged with electricity of the same polarity as the polarity of toner particles due to frictional electrification caused at the time of feeding of a recording medium. The heating and the backup roller are polarized reverse to the polarity of the recording medium. A quantity of charged electricity on the backup roller is made larger than that on the heating roller. This permits the image formation apparatus to prevent offset from occurring at the time of fixing a toner image onto the recording medium to cope with various types of recording media.

Fixing device improved in offset-prevention

Two pairs of legs are fitted under two side plates of an electrophotography apparatus, respectively. The two legs in one pair fitted under one of the side plates are disposed on either side of and are spaced from a point which is a cross point of a line joining these two legs, and a line perpendicular to this line, which perpendicular line passes through a projected point obtained by projecting the center of gravity of the electrophotography apparatus onto a horizontal plane on which the apparatus is set up. The two legs in the pair fitted under the other one of the side plates are disposed on either side of and are spaced from a point which is a cross point of a line passing these two legs and a line perpendicular to this line, which perpendicular line passes through the projected point of the center of gravity. The ratio of a shorter distance to a longer distance, of two distances: one between the two legs in a pair and the other between the two legs in the other pair is set to a value of 1/5 to 1/3. With such a arrangement, a defect in an image caused by a distortion in said side plates, due to a position change in the center of gravity of the electrophotography apparatus can be prevented.

Electrophotography apparatus

The top surface of the exterior case of a printing apparatus is formed of a first top surface portion which lies substantially above a fixation unit and a paper ejector, a second top surface portion which lies substantially above a control unit, and a third top surface portion which lies substantially above development units, a photosensitive belt and a transfer drum. The levels of the respective top surface portions are higher in the order of the first top surface portion, the second top surface portion and the third top surface portion. Top surface portions of higher levels are located from the front of the upper surface of the exterior case toward the back.

Laser beam printer

Printer for electronic computer

There is disclosed an optical scanning system in which axis alignment in a subscanning direction and adjustment of a spot is easily performed, the spot diameter is variable and a change in efficiency of an optical path due to these changes is small. The optical scanning system comprises two flat plate glasses which are provided between a cylindrical lens for converging an optical beam in a subscanning direction and a polygon mirror and are rotatable around an axis perpendicular to the subscanning direction and may be fixed after an adjustment. Axis alignment in a subscanning direction is obtainable by adjustment of the angle of one flat plate glass, and change in the spot diameter is obtainable by rotating two flat plate glasses in opposite directions while change of the axis in the subscanning direction and change in efficiency of the optical path are kept small.

Optical scanning apparatus and recording apparatus using the same

An optical scanning apparatus includes a light source, an image forming optical unit, a deflection unit and an optical beam detection unit provided inside a deflection area of the optical beam, the optical beam detection unit receiving the optical beam and generating a synchronizing signal. The optical beam detecting unit includes a unidirectional converging optical unit. This unidirectional converging optical unit is provided on an optical path of the optical beam irradiating the scanned surface for further converging the optical beam in a direction perpendicular to the direction of scanning in addition to the convergence performed by the image forming optical unit, so that the optical beam irradiating a light receiving surface of the optical beam detection unit can be focused in advance of the light-receiving surface of the optical beam detection unit in the above direction. In consequence, the allowable range of a shift of the scanning path of the optical beam caused by the manufacturing errors of the deflection unit and of a shift of an optical axis caused by the fine adjustment errors or strains of the supporting members can be increased. It is thus possible to provide an optical beam scanning apparatus which has a simple configuration and which enables the accuracy with which the position of the optical beam is detected to be improved.

Optical scanning apparatus

An alignment disk having an adjust signal recorded thereon to maintain data interchangeability of a magnetic disk drive apparatus and loadable and unloadable to and from the magnetic disk drive apparatus, and method and apparatus for verifying a tracking errors of the magnetic disk drive apparatus are disclosed; the magnetic disk drive apparatus including magnetic head means for recording and reproducing data on and from a magnetic recording medium, a head carriage for carrying the magnetic head means, and drive means for driving the head carriage radially of a track of the magnetic recording medium; the alignment disk having a set of track diameter adjust signal pairs recorded on tracks equal to or larger in number than the number of phases of a stepping motor for driving the head carriage and corresponding to at least the excitation phases of the stepping motor; the set of track diameter adjust signal pairs each having an inner track signal and an outer track signal extending inward and outward from a center of the track; and the set of track diameter adjust signal pairs being arranged symmetrically about a rotation axis of the disk.

Alignment disk for magnetic disk driving apparatus and method and

Growing community of inventors

Hitachi, Japan

Kazuo Kikuchi