Sharp Kabushiki Kaisha Corporation

Sharp Corporation

Eiichi Kido

Shigeyuki Wakada

Takayuki Yamanaka

Yuhi Yui

Toshihide Ohgoshi

Hiroshi Ishii

Atsushi Inoue

Jitsuo Masuda

Masahiro Sakai

Toshiaki Ino

Hiroaki Yoshida

Keizo Fukunaga

Toyokazu Mori

Hiroshige Araki

Toshihiro Ota

Syoichiro Yoshiura

Toshio Yamanaka

Fumio Shimazu

Masaru Tsuji

Shirou Wakahara

Hiroaki Nakaya

Takashi Kitagawa

Hiroshi Tatsumi

Itaru Kawabata

Hideo Yamasa

Hiromu Yoshimoto

Satoshi Murakami

Yuichi Kazaki

Shinji Imagawa

Yasuo Imai

Koichi Inui

Keiji Katoh

Yohichi Takesawa

Yoshikazu Kawasaki

Yuuhi Yui

Tadashi Iwamatsu

Shigeki Hayashi

Kunio Ohashi

Hideaki Kadowaki

Yoshikazu Harada

Katsumi Adachi

Junichi Saito

Takashi Hayakawa

Tadasu Taniguchi

Tetsuro Toyoshima

Fumito Mizoguchi

Shunju Anzai

Toshio Nishino

Yoshiharu Tsujimoto

Masayasu Narimatsu

Takashi Sakai

Mitsuyoshi Terada

Yoshinori Otsuka

Koichi Moriyama

Hideji Saikoh

Takahiro Kawakami

Yoshinori Ohtsuka

Kaori Dakeshita

Hiroshi Kataoka

Naoki Fukudo

Junji Morimoto

Hidenobu Yamane

Tokio Awata

Kaori Fujii

Mikie Kobayashi

Syunju Anzai

An image forming apparatus includes: a latent image bearing member on which an electrostatic latent image is to be formed; a developing unit which contains the developer and performs a development process to develop the electrostatic latent image formed on the latent image bearing member; and a movement mechanism which moves the developing unit toward the latent image bearing member when the development process is performed, and moves the developing unit away from the latent image bearing member and changes the attitude of the developing unit with, respect to the latent image bearing member when the development process is not performed.

Image forming apparatus with movable developing unit

One embodiment of an image forming apparatus according to the present invention includes an image forming apparatus provided with a one-component development apparatus having a toner layer regulating blade for regulating a thickness of a toner layer on a surface of a developer bearing member that contacts a photosensitive body, wherein at a non-development time after completion of operation of the developer bearing member, the developer bearing member is caused to rotate slightly in a direction reverse to that during development.

Image forming apparatus provided with one-component development apparatus

A blade cleaning jig includes a cleaning portion and a gripping portion. The cleaning portion includes a support body of stainless steel or the like and polishing tape provided on the upper face of this support body, and moreover a cushioning material is inserted between the support body and the polishing tape. A protective member for preventing damage to the surface of a developer roller is attached to the entire lower face of the support body. This protective member is attached bent at a circumferential end portion such that the protective member covers from the lower face of the support body via a circumferential edge portion to an upper face circumferential edge portion.

Blade cleaning jig

An developing device in which a developing roller develops an electrostatic latent image on a photo conductor; a developing roller driving unit rotates the developing roller in a forward direction and in a backward direction respectively while development is performed and not performed; a thickness regulating member, which is pressed against a surface of the developing roller, regulates a thickness of developer adhered to the surface of the developing roller; and a suppression unit suppresses a pressing force of the thickness regulating member when the developing roller is rotating in the backward direction.

Developing device having thickness regulating member and image forming apparatus

A development apparatus includes an auger conveyor member for stirring and conveying developer, the gravity of the developer being eccentrically distributed with respect to a center of rotation, a drive transfer member for driving and rotating the auger conveyor member, the drive transfer member being capable of being engaged and disengaged, and a rotation detector for detecting a rotational state of the auger conveyor member. The remaining amount of the developer is detected based on the rotational state detected by the rotation detector. Alternatively, a development apparatus includes the auger conveyor member and the drive transfer member, in which the eccentric gravity distribution is achieved by a rod-like weight member eccentrically provided with respect to a rotational axis, the auger conveyor member includes a first coil spring having an inner diameter larger than an outer diameter of the weight member, and the first coil spring is inserted around the weight member in a manner which allows the first coil spring to be rotated and limits an angle of rotation of the first coil spring to a predetermined angle. Alternatively, a development apparatus includes the auger conveyor member and the drive transfer member, in which the auger conveyor member is provided near a development supply roller, and a uniforming member for making the developer uniform is provided in a space portion between the development supply roller and the auger conveyor member.

Developing agent detecting mechanism section of developing apparatus

An image forming apparatus is provided with a photoreceptor drum which includes a cylindrical drum whose surface is coated with a photosensitive layer, and a rear-side drum flange section; and a developer. A coupling section at which the photoreceptor drum is attached to or detached from an image forming apparatus main body includes an input section and an apparatus output section. The input section is includes an internal gear having teeth of an involute curve formed in an inner surface of the rear-side flange section and receives rotation driving force from the image forming apparatus main body. The apparatus output section is composed of an external gear having teeth in the same shape and in the number as the internal gear, and outputs the rotation driving force from the image forming apparatus main body to the input section.

Photoreceptor drum and image forming apparatus

Before replacement of constituent parts of an image density sensor or of other image forming units, the image density of a formed test toner patch image is detected by the image density sensor and conditions for image formation are controlled. After replacement of the constituent parts, the image density sensor detects the image density of a test toner patch image which is formed based on the controlled conditions for image formation. The optical output and/or the optical sensitivity is adjusted so that a detected value becomes a predetermined reference value, to calibrate the image density sensor. With this image formation controlling method, the image density sensor can be calibrated easily and precisely, the image density of a toner pattern image can be held proper and a stable high-quality image can be obtained.

Image formation controlling method and image forming apparatus

An optical electric charge removal device mountable on an image formation apparatus of an electrophotographic system for removing residual charges on a photosensitive member by light irradiation is provided. The optical electric charge removal device includes a point light source provided in the image formation apparatus; and an optical conductor, mountable on a process cartridge which is detachable from the image formation apparatus, for guiding light incident from the point light source to the photosensitive member.

Optical electric charge removal device and image formation apparatus including the same

A developing apparatus capable of supplying a uniform thin layer of toner and of preventing toner scattering and leakage is provided, where the developing apparatus includes a supply roller for supplying toner to an outer peripheral surface of a toner carrier, the toner carrier for transferring the supplied toner by rotation and a layer thickness controlling member for controlling a thickness of the layer of the supplied toner at a predetermined value while making slide contact with the outer peripheral surface of the toner carrier via the toner, wherein the thin toner layer is supplied to an electrostatic latent image on an image carrier. The layer thickness controlling member is formed of an elastic plate to have a bent portion convex toward the toner carrier. The layer thickness controlling member is held by sealing members so that the bent portion makes elastic contact with the toner carrier outer peripheral surface over a nearly entire length of the toner carrier.

Developing apparatus

An object of the invention is to transport safely and reliably a unit such as a developing cartridge in which toner is used, and toner, and to reduce the dimensions and cost of an apparatus for packaging such a unit. Two buffer members are fixed to two opposite widthwise end sides of a developing cartridge, and the resultant combination is accommodated in a packaging box. Each buffer member has a hollow structure formed by blow molding a thermoplastic resin material. The toner is inserted into the interior of each buffer member from an opening thereof, and the buffer members and a non-toner-charged developing cartridge can be packaged together and transported. When the toner in each buffer member is supplied via the opening thereof to the interior of the developing cartridge after the transportation of these parts is completed, a structure in the developing cartridge for preventing the coagulation and leakage of the toner being transported can be simplified, and cost reduction can be effected. Since dead space in the packaging box is effectively utilized for the transportation of the toner, the safety of the transportation and a decrease in cost can be attained.

Apparatus and method for packaging unit having toner storage

Toner image forming means for forming toner images having chromatic colors of Y, M and C, respectively, are disposed on one side of an intermediate transfer belt, while disposing toner image forming means for forming a black toner image on the other side of the intermediate transfer belt, alone and on a most downstream side of all the toner image forming means. Further, when a toner image on the intermediate transfer belt includes toner having a reverse polarity, a transfer or developing process is controlled to reduce electrostatic attraction force acting on an image carrier, thus providing a color image forming device having a main body reduced in size and capable of faster image formation of a monochromatic image which is more frequently used, and of efficiently forming a color image by suppressing a back-transfer phenomenon and improving color reproducibility.

Tandem type color image forming device

A cleaning element is arranged on the backside of the toner layer metering blade, i.e., the side opposite to the surface in contact with the developer support, in order to prevent the cleaning element from damaging the blade surface and the abutment surface of the metering blade against the developer support. This cleaning element is frictionally moved across the backside of the toner layer metering blade to remove stuck toner from the toner layer metering blade or prevent occurrence of buildups.

Developer unit with cleaning element

The image forming portion of this image forming apparatus includes a LSU, a photosensitive drum, a developing unit holder, a multiple number of developing units, an intermediate transfer element, a transfer element and a fixing unit. All the developing units are of an identical configuration. Therefore, for replacement of developing units, the operator may and should remove any color of developing unit in the same fashion and attach a fresh developing unit of the color in the same fashion. The image forming portion sets up the image forming conditions for individual colors in the developing order.

Image forming apparatus

When electrostatic capacity C,&lsqb;F/m,&rsqb; per unit area of an elastic member when an ac voltage of an arbitrary frequency f &lsqb;Hz&rsqb; is applied is given by C,&equals;C,&middot;(f/1000),, using electrostatic capacity C,&lsqb;F/m,&rsqb; per unit area when an ac voltage of 1 kHz is applied and using a rate of change a, electrostatic capacity C of a micro-region of an elastic member per unit area is substituted with C,per each frequency component which forms a voltage of a rectangular pulse equivalent to a voltage applied to a charge system. Then, the elastic member is made of such a material that the rate of change a falls within a range of a &lE;&minus;0.1544&middot;log(C,/C,) &plus;0.0307, and further, within a range of a &lE;&minus;0.146&middot;log(C,/C,) &minus;0.0688. Consequently, it is possible to provide a contact charging device which incorporates conditions for improving charge uniformity, which are obtained by taking frequency characteristics of the electrostatic capacity into consideration.

Contact charging device

An image forming apparatus, includes: a rotatable photosensitive member; a charging brush for uniformly charging the photosensitive member; a light scanning and irradiating portion for illuminating the photosensitive member scan-wise; a developing roller for supplying the toner to the static latent image on the photosensitive member to create a toner image; and a rotatable transfer roller arranged opposing the photosensitive member and urged against the photosensitive member by urging elements arranged around both ends thereof for allowing the toner image to a print medium. In this arrangement, the peripheral surface speed of the transfer roller is set at a speed slower, by less than about 2.3%, relative to the peripheral surface speed of the photosensitive member, and the length of the transfer roller is set shorter by the distance not exceeding about 6 mm than the maximum width of the reproducible print media, in the direction of the length.

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Nara, Japan

Eiichi Kido