Sharp Kabushiki Kaisha Corporation

Tatsuya Inoue

Toshiki Takiguchi

Yoshiharu Yoneda

Shinji Nakazawa

Kouji Wakamoto

Hirokazu Yamauchi

Hiroshi Kida

Junya Masuda

Shinichi Takeda

Masao Matsui

Shuhji Fujii

Yasuhiro Takai

Kazuhiro Matsuyama

Yoshitaka Okahashi

Koji Wakamoto

Syoichiro Yoshiura

Hiroshi Ishii

Hideaki Kadowaki

Nobuyuki Ueda

Takashi Yamanaka

Tsutomu Yoshimoto

Masashi Hirai

Masahiko Fujita

Shoichiro Yoshiura

Shiro Narikawa

Hiroyuki Nagao

Hiranaga Yamamoto

Yoshiaki Masuda

Kan Mukai

Shinji Sugita

Fuminori Miyoshi

Ken-ichi Iwamoto

Atsushi Ogo

Junko Yabuta

Kiyoshi Sasoh

Hidetoshi Atsumi

Mitsuo Matsuda

Kouichi Matsumoto

A pair of registration rollers are provided upstream in a paper transport path from an image forming position, and a paper transport position detection portion is provided upstream in the paper transport path from the pair of registration rollers. When consecutive print processing on a plurality of sheets of paper is performed, a paper transport position in the paper transport path is detected by the paper transport position detection portion for a sheet of paper that has been set in advance among the plurality of sheets of paper. A correction amount of a position for image writing to a photosensitive drum is determined based on the paper transport position, and correction of the image writing position is performed based on the correction amount. Image forming on the sheet of paper is performed at the image forming position based on the image writing position after correction, and image forming on other sheets of paper after the sheet of paper that was set in advance is performed at the image forming position based on the image writing position after correction.

Image forming apparatus

A cleaning member for cleaning the toner remaining on the outer peripheral surface of a heat roller that fixes an unfixed developer image formed on a sheet of paper onto the paper by heating under pressure, includes: a mesh portion having a predetermined mesh in the area abutting the heat roller. The mesh portion is formed of heat resistant wires.

Cleaning member and image forming apparatus using the same

In an image forming apparatus of the present invention, an idle roller once stops rotating when a front edge of a sheet conveyed reaches the idle roller. The idle roller restarts rotating at such a timing that a front edge of a toner image on a photoreceptor and a front edge of an image writing position on the sheet are aligned with each other. Then, even if a rear edge of the sheet is still in the idle roller, the idle roller stops rotating when the front edge of the sheet is sandwiched between a transfer roller and the photoreceptor. By carrying out such operations, it is possible to avoid by a very simple way an occurrence of a slip phenomenon that is a phenomenon of slipping of the sheet with respect to the photoreceptor while suppressing a reduction in image quality as much as possible. In addition, it is also possible to surely secure a blank space formed at a rear edge portion of the sheet.

In an image forming apparatus of the present invention, a scorotron charging device has a meshed grid electrode which is meshed more coarsely in a high-speed apparatus than a meshed grid electrode in a low-speed apparatus according to a circumferential velocity of a photoreceptor. With this arrangement, it is possible to charge the photoreceptor at a predetermined potential in the high-speed apparatus, without increase of the amount of ozone generation and upsizing of the image forming apparatus.

Charging device and electrophotographic apparatus including the same

An image forming apparatus carries out an image processing with respect to a sheet size and image information based on a print request to obtain a write image on a photoreceptor. On the basis of a printing ratio of the write image, the apparatus predicts occurrence of an image elongation. If the apparatus predicts that the image elongation occurs, the apparatus calculates a bending amount of a bended portion based on the difference between peripheral velocities of a photoreceptor and the idle roller, and the apparatus variably controls the peripheral velocity of an idle roller so that the bending amount is adjusted so as not to cause a slip phenomenon. It is possible to avoid the occurrence of a phenomenon of slipping of a sheet with respect to the photoreceptor without lowering image quality, and to surely secure a blank space formed at a rear edge portion of the sheet.

An image forming device includes a first carriage path for carrying paper stored in a paper feeding tray to a printer, there is a second carriage path for carrying paper stored in a second paper feeding tray to the printer. The first carriage path and the second carriage path individually carry a paper to the printer.

Image forming device

An image forming apparatus of the present invention carries out an image processing with respect to image information which is to be printed. The image forming apparatus predicts the occurrence of an image elongation which may occur due to slippage of a recording material with respect to the electrostatic image drum, and specifies an image elongation occurring area on the basis of a printing ratio of the image information. If the occurrence of slippage, and thus image elongation is predicted, the amount of the image elongation occurring area to be shortened is calculated. The image information is then modified to obtain write image information that is shortened based on the calculated shortening amount. This write image information is then used to form the electrostatic latent image that is developed and transferred to a recording material. Thus, even slippage does occur, it is possible to accurately form the desired image on the recording material.

An image forming apparatus includes a history storage portion for storing the usage history involving the number of prints of the image forming apparatus, and a processing time controller for changing the time of the pre-processing operation before or the time of the post-processing operation after a printing process of the printing portion, based on the stored usage history so as to exclude the influence of the unfixed developer on the printing process.

Image forming apparatus with adaptive pre-processing and post-processing based on usage history

An image forming apparatus of the present invention predicts the occurrence of an image elongation, in other words, predicts that an image transferred is lengthened on a sheet due to slipping of the sheet with respect to a photoreceptor at a transfer nip portion. If the occurrence of the image elongation is predicted, the amount of a rear edge portion to be deleted from an electrostatic latent image is obtained on the basis of a sheet rear edge void setting change table, the amount of the rear edge portion to be deleted is added to the default amount of a rear edge void, a portion corresponding to the rear edge portion of an image of image information is deleted, and a printing process is carried out. In this way, even if a slip phenomenon occurs, in other words, the sheet slips with respect to the photoreceptor, it is possible to surely secure a blank space at a rear edge portion of the sheet.

An image forming apparatus including a sheet conveying apparatus. When a sheet is jammed in a first conveying path, a first unit is pulled out in a direction substantially parallel to a first conveying path. In this way, a driven roller and a driving roller are separated from each other, and a work space is created. The jammed sheet is thus exposed to the first conveying path. It is therefore easy to put a hand into the work space and remove the sheet. This allows for easy maintenance, and easy operation for removing a sheet retained in the apparatus.

Sheet conveying apparatus and image forming apparatus using the same

A sheet feeding device for an image forming apparatus can perform various operations. These are, for example, an operation to start an image formation and an output process that inhibits opening and closing of a feeding route interlocked with opening and closing of a storage section. This is done if the received operation or a process executed based on the operation satisfies a preset predetermined condition.

Sheet feeding device and image forming apparatus

An image forming apparatus includes, for example, a first knob serving as a first operating member for manually turning a registration roller member in a sheet transporting unit and a second knob serving as a second operating member for manually turning a fixing roller in a fixing device. The first and second operating devices, such as knobs, are provided in such a manner as to be exposed onto a side of the apparatus body facing a direction perpendicular to a direction in which the cabinet may be opened.

Cabinet opening structure and image forming apparatus

A link member interlinks an external member forming part of a cabinet of an apparatus and an internal member capable of pivoting about a pivot shaft located more deeply inside the apparatus than the external member for causing the internal member to pivot in cooperation with the external member pivoting. The link member has a stretchable length and is provided with a resilient biasing member biasing the link member in such a direction as to stretch the length. When the external member is in its closed position, the internal member is positioned to abut a predetermined contact portion by the biasing force of the resilient biasing member. Parts storage shelves are provided in the space defined between the external member and the internal member.

Open/close mechanism and image forming apparatus using the same

A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

Image device with control members for rollers

There are provided a conveying path provided in an apparatus body and serving to convey a sheet-like object in a longitudinal direction, a moving body capable of being moved to a position in which the conveying path is to be exposed and a position in which the sheet-like object can be conveyed to cover the conveying path, and at least three support members for supporting the moving body to be slid in an almost horizontal direction with respect to the apparatus body and to be separated or joined are provided on a lower end portion at the side that a user accesses for a jam processing in the moving body and both upper and lower end portions at the opposite side thereof. Accordingly, in the case in which the user is to carry out the jam processing by separating the moving body from the apparatus body, a jammed paper in the conveying path can be removed easily.

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Nara, Japan

Tatsuya Inoue