Sharp Kabushiki Kaisha Corporation

Masashi Hirai

Fumio Shimazu

Hiroshi Tachiki

Toshio Yamanaka

Toshiki Takiguchi

Hirokazu Yamauchi

Yuji Nakagawa

Toshiaki Kagawa

Kuniaki Nakano

Susumu Murakami

Kohichi Yamauchi

Osamu Nakayama

Noritaka Okazaki

Kazuaki Ishikawa

Kazuhiro Matsuyama

Takashi Mukai

Yoshinobu Tateishi

Atsushi Ide

Masahiko Fujita

Osamu Fujimoto

Yoshiharu Yoneda

Toshiya Mikita

Fumito Mizoguchi

Yoshiaki Masuda

Masanori Yamada

Hidekazu Sakagami

Mitsuyoshi Terada

Yasuji Yamauchi

Takahiko Yoshida

Masafumi Okumura

Kyousuke Taka

Kinji Uno

Syoichiro Yoshiura

Hiroshi Kida

Katsumi Adachi

Kiyoshi Toizumi

Takahiro Fukunaga

Hideo Matsuda

Mikio Kakui

Tatsuya Inoue

Tomomi Tanaka

Hiroyuki Murai

Hiroshi Kinashi

Yoshiharu Tsujimoto

Kouichi Yamauchi

Shogo Yokota

Tamaki Mashiba

Masaki Saka

Shigeru Watase

Koichi Nakamura

Toshihide Morimoto

Yukio Nakai

Toshiro Kurishita

Zitsuo Masuda

A belt unit is provided with an endless belt, a driving roller, and a pair of guide ribs. The driving roller is disposed on an inner peripheral surface side of the endless belt and drives the endless belt. The pair of guide ribs is placed on each opposite widthwise end of the inner peripheral surface of the endless belt and contacts both end faces of the driving roller, thus preventing meandering of the endless belt. Additionally, the driving roller is equipped with a low friction region at both opposite lengthwise ends in a predetermined width and the low friction region is configured to have a friction coefficient that is lower than a friction coefficient of a region adjacent to the low friction region.

Belt unit and image forming apparatus

An image forming apparatus () is equipped with a plurality of photoreceptor drums (A toD), an intermediate transfer belt (), a separating and contacting mechanisms (), a tension roller (), a meandering correction mechanism, and a controller. The separating and contacting mechanism () displaces the intermediate transfer belt (). The meandering correction mechanism increases and decreases a biasing force applied to each of the opposite end portions of the tension roller () according to the amount of movement of the intermediate transfer belt () in the axial direction () of the tension roller (). The controller, during a non-image forming period, at a predetermined timing during rotation of the intermediate transfer belt (), executes a belt displacement process in which the intermediate transfer belt () is displaced from a predetermined reference position and then returned to the reference position.

Image forming apparatus

A belt conveyor member includes an endless belt and a cleaning blade. The cleaning blade is configured to remove residual toner remaining on a surface of the endless belt which is processed into a smooth surface. The endless belt has a first region and a second region. The first region is a region in contact with the cleaning blade which is located outside a region for a recording sheet of a maximum usable width to pass therethrough. The second region is located outside the first region. A contact surface between the cleaning blade and the first region is in a rough condition free from intimate contact.

Belt conveyor member and image forming apparatus

An image forming apparatus includes a PTC and a toner concentration sensor that are disposed adjacent to and downstream of a fourth image forming unit. The PTC and the toner concentration sensor are opposed to an intermediate transfer belt. A counter roller is opposed to the PTC across the intermediate transfer belt. The counter roller moves to, during the toner concentration detection, a position opposed to the toner concentration sensor across the intermediate transfer belt. Compared to the PTC and the toner concentration sensor each having a counter roller, less rollers may be provided, thereby reducing degradation of the intermediate transfer belt due to wear.

Image forming apparatus of intermediate transfer method, including pre-secondary-transfer charging section and concentration detection section

A fixing device of the present invention includes: an external heating belt which is to contact with a surface of a fixing roller so as to heat up the fixing roller; and a cleaning member (a scraper and/or cleaning pad) which is to contact with the external heating belt. The cleaning pad which is impregnated with silicone oil is to contact with a surface of the external heating belt, thereby applying the silicone oil (release agent) to the surface of the external heating belt. This makes it possible to prevent generation of an offset.

Fixing device and image forming apparatus having same

In a fixing device including (i) an external heat belt which abuts against a surface of a fixing roller so as to heat the fixing roller and (ii) a cleaning member which abuts against the external heat belt, a fixing temperature, which is a surface temperature of the fixing roller during a fixing process, is set per group into which recording media to be subjected to the fixing process are divided according to their widths in a direction of a rotary axis of the fixing roller, in such a way that the fixing temperature is set to a lower temperature for a group of narrower widths. This makes it possible to prevent a reduction in releasability of the fixing roller caused by a material, which is scraped off from the external heat belt by the cleaning member and then adhered to the fixing roller, thereby preventing the high-temperature offset.

Fixing device, image forming apparatus, and method for controlling fixing device

An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 &#x3bc;m to 50 &#x3bc;m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cmto 40 gf/cm.

Transfer belt unit and image forming apparatus using the same

A surface of a discharge electrode of an ion generating device of the present invention, other than a surface in contact with a dielectric body, is coated with a protective layer made of a metal that is gold or a combination of gold and nickel. This allows the ion generating device to generate ions evenly and stably, and to have a longer life.

Ion generating device with a discharge electrode on a dielectric body coated by a protective layer made of metal

An ion generating device provided in an image forming apparatus of the present invention as a charging device for charging before a first transfer, a charging device for charging before a second transfer, or a charge device for charging an electrostatic latent image is arranged such that a discharge electrode can move with respect to a dielectric material and the relative positions of the discharge electrode and the dielectric material can be changed. This makes it possible to provide: a long-life ion generating device whose life has been extended by making effective use of a dielectric material; and an image forming apparatus including the ion generating device.

Ion generating device and image forming apparatus including same

A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred from a photoreceptor drum and (ii) moves a surface holding the toner image; and a secondary transfer belt that comes into contact with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes a cleaning unit that removes and collects toner from the surface of the intermediate transfer belt. The transfer unit also includes a power source for sequentially applying, to the secondary transfer belt, (i) a first voltage for generating an electric field that transfers normally-charged toner from the secondary transfer belt to the intermediate transfer belt and (ii) a second voltage for generating an electric field that transfers oppositely-charged toner from the secondary transfer belt to the intermediate transfer belt.

Transfer unit, transfer method, and image forming apparatus

Providing a simply-arranged detaching/attaching mechanism and image forming device which allow a transfer supporter device to be detached/attached through a space formed by opening an outer covering, the device includes photosensitive drums, detachable/attachable transfer belt unit, and rail members supporting a transfer belt unit. Each of the rail members includes a rail groove guiding the transfer belt unit, notch and positioning hole determining the position of the transfer belt unit when the belt is in contact with the photosensitive drums, and notch and convex section determining the position of the transfer belt unit when the belt is detached from the photosensitive drums. The transfer belt unit support with respect to the main body of the image forming device, performed by the rail members, is released in response to the action of opening the side cover, so that the transfer belt unit is in a free state.

Detaching/attaching mechanism and image forming device

An image forming apparatus is provided with a latent image carrier for holding an electrostatic latent image, and an intermediate transfer member for temporally holding an image formed by visualizing the electrostatic latent image formed on the latent image carrier. The image forming apparatus performs image formation by superimposing a plurality of images on the intermediate transfer member so as to form a superimposing image, and transferring the superimposing image on a recording medium. The intermediate transfer member has a latent image holding property for holding the electrostatic latent image. An image formed by visualizing an electrostatic latent image formed on the intermediate transfer member is superimposed with the electrostatic latent image formed on the latent image carrier.

Image formation device and image forming method using same

A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.

Transfer belt device and image forming apparatus

A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Transfer device and image forming apparatus

Growing community of inventors

Katano, Japan

Masashi Hirai