Canon Kabushiki Kaisha

Kenya Ogawa

Yasushi Shimizu

Katsuhiro Sakaizawa

Kazunari Hagiwara

Shuji Moriya

Yukihiro Ohzeki

Yasunori Chigono

Koichi Okuda

Naoto Kichijima

Yasushi Sato

Hikaru Osada

Kouichi Okuda

Takeshi Yamamoto

Noboru Koumura

Masaki Ojima

Hideyuki Yano

Katsuhiko Oba

Yukihide Ushio

Kenji Muto

Izumi Narita

Yukihiro Ozeki

Masatake Usui

Motoi Kato

Shunichi Ebihara

Naohiro Nakane

Kazunori Taira

A developing apparatus having a developing sleeve provided with an elastic layer on its surface, and for developing an electrostatic image formed on an image bearing member with a mono-component magnetic toner having a mean degree of circularity of 0.965 or greater, a magnet provided in the developing sleeve, and a blade for regulating the amount of the developer carried on the developing sleeve satisfies the expressions |Br|/|B|&#x2267;0.5 and Nsb/(Bs&#xd7;R)&#x2266;0.5, where B (G) is magnetic flux density formed on the surface of the developing sleeve by the magnet at the contact position between the blade and the developing sleeve, Nsb (mm) is the contact width between the blade and the developing sleeve, Br (G) is a component of magnetic flux density B (G) in a direction perpendicular to the surface of the developing sleeve, Bs (rad) is a half value width of the perpendicular component of the magnetic flux density of the nearest one of the magnetic poles of the magnet to the contact position on the surface of the developing sleeve, and R (mm) is the radius of the developing sleeve.

Developing apparatus featuring image defect supression

A developing apparatus includes a developing roller for developing an image with a developer; a non-rotary magnet roll inside the roller; a blade; and an abutting member abutting against the roller, wherein the following expressions are satisfied: |Vs|&#x3e;|Vdev|, |Br|/|B|&#x2266;0.5, and L/(BH&#xd7;R)&#x2267;0.1, where |Vdev|: a DC component Vdev of a voltage applied to the roller, |Vs|: a DC component Vs of a voltage applied to the member, B(G): the magnetic flux density formed on the surface of the roller at the abutting position by the magnet roll, Br(G): the component of the magnetic flux density B(G) perpendicular to the surface of the roller, and L(mm): the abutting width between the roller and the member, BH(rad): the half value width of the component B&#x3b8;(G) horizontal to the surface of the roller, and R(mm): the radius of the roller.

Developing apparatus for preventing ghost images and uneven image density

A developing apparatus having a rotatable developing sleeve having an elastic layer on the surface thereof for carrying a mono-component magnetic developer and urged against a photosensitive drum to develop an electrostatic image formed on the drum with the developer, a non-rotary magnet provided inside the sleeve for magnetically attracting the developer to the sleeve, and a blade having an abutting portion abutting against the sleeve in a counter direction for regulating the amount of the developer on the sleeve, a step portion spaced apart from the abutting portion, and a separating portion provided upstream of the step portion in the rotation direction of the sleeve, wherein the surface of the sleeve to which the separating portion is opposed includes a position satisfying |Br|/|B|&#x2267;0.5, where B(G): the magnitude of magnetic flux density formed on the surface of the sleeve, and Br(G): a component of the magnetic flux density in a direction perpendicular to the surface of the sleeve.

Developing apparatus

A developing apparatus includes a developer carrying member for carrying a developer including one component magnetic toner to develop an electrostatic image formed on an image bearing member. The developer carrying member includes an elastic member contactable to the image bearing member; magnetic field generating means, for attracting the developer to the developer carrying member, and a regulating member for regulating an amount of the developer carried on the developer carrying member. The developer is regulated by the regulating member and applied on the developer carrying member at 5-16 g/mk. At a position where the regulating member is contacted to the developer carrying member, a magnetic flux density B generated by the magnetic field generating means, and a component Br of the magnetic flux density B normal to a surface of the developer carrying member, satisfy, |Br|/|B|&#x2266;0.5.

Developing apparatus including magnetic field generating means, for use with a developer which includes a magnetic toner component

A developing device includes a rotatable developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with the developer; non-rotatable magnetic field generating means, disposed inside the developer carrying member, for magnetically attracting the developer on the developer carrying member; a regulating member for regulating an amount of the developer carried on the developer carrying member, wherein the developer carrying member is provided with a surface elastic layer, and the developer carrying member is press-contacted to the image bearing member, and wherein, the developer is an one component magnetic toner having an average circularity not less than 0.965, and an amount of the developer per unit area of the developer regulated by the regulating member is 5-14 g/m, and an amount of electric charge thereof is 10-50 &#x3bc;C/g.

Developing apparatus featuring a developer carrying member with an elastic surface layer

An image heating apparatus has a flexible rotatable member; a slidable member for sliding contact with an inner surface of the rotatable member; a back-up member for forming a nip with the slidable member with the rotatable member interposed therebetween, wherein a projection extended along a longitudinal direction of the rotatable member, and provided on such a portion of a sliding surface of the slidable member as is downstream of a center of the sliding surface with respect to a recording material feeding direction in which the recording material is fed, and wherein the projection is effective to provide a maximum pressure in a distribution, with respect to the recording material feeding direction, of pressure applied to the nip.

Image heating apparatus having recording medium conveying nip nonuniform in pressure distribution

A fixing member having the form of a film or belt which is multi-layer constructed to have at least a base layer and a surface layer. The base layer is formed of a material having radiation-transmitting properties, capable of transmitting radiation coming from a radiation source disposed on the back side of the base layer in non-contact with the fixing member. Also disclosed is a fixing assembly having this fixing member and a radiation source disposed on the internal side of the fixing member. Even though the radiation source is disposed on the internal side of the fixing member, the fixing member can perform good surface heating in a good heat response.

Fixing member having layers with radiation-transmitting and radiation-absorbing properties, and a fixing assembly including such a fixing member

A developing apparatus has a developer carrying member for carrying a developer thereon and conveying it to a developing area opposed to an image bearing member, an agitating member for agitating the developer to be supplied to the developer carrying member and a stripping device for stripping off the developer having passed the developing area from the developer carrying member wherein the developer stripped off from the developer carrying member by the stripping device is guided to a position farther from the developer carrying member than a position at which the agitating member is disposed.

Developing apparatus featuring first and second developer chambers and guide member for directing stripped-off developer

A hybrid type image forming apparatus capable of forming a high quality image by using two image forming units having different resolution from each other, perform high throughput image forming by selecting most suitable image forming method or methods depending upon a kind of input image data, and reducing its running cost. In the apparatus, input image data of resolution of 300 dpi is separated into monochromatic image data and color image data. The monochromatic image data is converted into that of 600 dpi so that four pixels of an image of 600 dpi make one pixel of an image of 300 dpi. Then, a monochromatic image is formed on the basis of the monochromatic image data of 600 dpi by the image forming unit employing the electrophotograph method. A print medium on which the monochromatic image is formed is conveyed to the image forming unit employing the ink-jet printing method where a color image is formed on the basis of the color image data of 300 dpi.

Image forming apparatus

An image forming apparatus for forming an image on a recording medium includes a first conveying path for conveying a recording medium in order to form an image thereon using a first image forming device, a second conveying path for conveying a recording medium in order to form an image thereon using a second image forming device for forming an image according to an image forming method different from an image forming method of the first image forming device, a third conveying path for conveying a recording medium in order to form an image thereon using the first image forming device and the second image forming device, and a setting device for selectively setting one of a first conveying mode using the first conveying path, a second conveying mode using the second conveying path, and a third conveying mode using the third conveying path.

Image forming apparatus with ink jet and electrophotographic image

An image forming apparatus includes an image bearing member for bearing an electrostatic image; a developer carrying member, opposed to the image bearing member, for carrying a one component developer which is charged to a predetermined polarity by friction between the developer and the developer carrying member; an electric field generating device for generating, between the image bearing member and developer carrying member, an electric field for developing the electrostatic image on the image bearing member with a reverse development method; a regulating member for regulating an amount of the developer on the developer carrying member; and a voltage applying device for applying to the regulating member, a voltage having a polarity opposite the predetermined polarity.

Developing apparatus that applies voltage to developer layer thickness

An image forming apparatus for forming an image on a recording medium includes a first transporting path for transporting the recording medium for forming an image on the recording medium by using a first image forming unit, a second transporting path for transporting the recording medium for forming an image on the recording medium by using a second image forming unit which forms the image by an image forming method which is different from a method employed by the first image forming unit, and a controller for controlling the apparatus in a black image selection mode, in which the first transporting path is selected in accordance with black image data for forming a black image on the recording medium, and the recording medium is transported through the selected first transporting path to form a black image on the recording medium, a color image selection mode, in which the second transporting path is selected in accordance with image data including color image data for forming a color image on the recording medium and the recording medium is transported through the selected second transporting path to form a color image on the recording medium, and a forcible selection mode in which the first transporting path is selected even if the image data includes color image data to transport the recording medium through the selected first transporting path to form a black image on the recording medium.

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Susono, Japan

Kenya Ogawa