Canon Kabushiki Kaisha

American Microsystems, Inc.

Toshiro Suzuki

Takumi Furukawa

Hiroaki Watanabe

Kenichi Yazawa

Jun Murata

Noriaki Kuroda

Yuya Tomomizu

Hisao Kato

Yukinori Nagata

Yoko Kuruma

Kenya Terada

Toshinari Miura

Kazuhiro Gesho

Masaki Ozawa

Satoru Yamada

Masaaki Harada

Taichi Sato

Michitaka Kitahara

Kazuyuki Shishitsuka

Atsushi Uematsu

Roubik Gregorian

Katsuya Kodama

Keiji Nose

Toshimitsu Nakazawa

Shinsuke Kokubo

An electrophotographic roller includes: a mandrel and an elastic layer on the mandrel, and having a crown shape in which a diameter decreases from a central position O in a longitudinal direction of the mandrel toward an end portion. When a position of the end portion in the longitudinal direction of the elastic layer is defined as X2, a position between the O and the X2 is defined as Xl, a distance between the O and the X1 is defined as L1, and a distance between the X1 and the X2 is defined as L2, L1=0.6&#xd7;(L1+L2). When outer diameters of the electrophotographic roller at O, X1 and X2 are defined as Do, DX1 and DX2, respectively, and Z1=(Do&#x2212;DX1)/2 and Z2=(DX1&#x2212;DX2)/2 are defined, Z1, Z2, L1 and L2 satisfy (Z2/L2)&#x3c;1.931&#xd7;(Z1/L1).

Electrophotographic roller, process cartridge and electrophotographic image forming apparatus

An electrophotographic roller includes: a mandrel and an elastic layer on the mandrel, and having a crown shape in which a diameter decreases from a central position O in a longitudinal direction of the mandrel toward an end portion. When a position of the end portion in the longitudinal direction of the elastic layer is defined as X2, a position between the O and the X2 is defined as X1, a distance between the O and the X1 is defined as L1, and a distance between the X1 and the X2 is defined as L2, L1=0.6&#xd7;(L1+L2). When outer diameters of the electrophotographic roller at O, X1 and X2 are defined as Do, DX1 and DX2, respectively, and Z1=(Do&#x2212;DX1)/2 and Z2=(DX1&#x2212;DX2)/2 are defined, Z1, Z2, L1 and L2 satisfy (Z2/L2)&#x3c;1.931&#xd7;(Z1/L1).

Provided is an electrophotographic roller including a cylindrical base and an elastic layer on an outer peripheral surface of the base, the base having a joint extending from one end to the other end in a longitudinal direction thereof, at least a part of the joint has a gap penetrating the joint in a thickness direction of the base, and a part of a material for the elastic layer entering the gap and covering a portion of an inner peripheral surface of the base near the gap to form an anchor portion of the elastic layer.

Electrophotographic roller, production method therefor, and electrophotographic apparatus

The charging member includes: an electroconductive support; and an electroconductive elastic layer serving as a surface layer, wherein the elastic layer contains a binder, and holds electrically insulating hollow particles in such a state that at least a part of each of the hollow particles is exposed at a surface of the elastic layer, wherein the charging member has protrusions derived from the hollow particles in an outer surface of the charging member, and the outer surface of the charging member includes an outer surface of the elastic layer and an outer surface of an exposed portion of each of the hollow particles, and wherein the protrusions each have a depression in an outer surface of each of the protrusions, and an edge of the depression constitutes an apex in each of the protrusions.

Charging member, electrophotographic process cartridge, and electrophotographic image forming apparatus

An electrophotographic roller includes an electro-conductive shaft core including a metallic layer at its surface, and an elastic layer on the shaft core. When kinetic friction coefficients of an outer peripheral surface of each end portion of the shaft core with respect to polyester resin are measured for one rotation of the shaft core, an average value &#x3bc;r of the kinetic friction coefficients is 0.05 to 0.50. When each outer peripheral surface is divided into three equal ranges, defined as a region A1, a region A2, and a region A3, in a peripheral direction of the shaft core, each of the regions has a location where the kinetic friction coefficients fall within a range of 1.5 &#x3bc;r to 1.8 &#x3bc;r, and a location where the kinetic friction coefficients fall within a range of 0.2 &#x3bc;r to 0.5 &#x3bc;r.

Electrophotographic roller and charging apparatus

Provided a charging member comprising an electro-conductive support and an electro-conductive surface layer, the surface layer including on the outer surface thereof, concave portions that are independent of each other, and holding an insulating particle in each of the concave portions, the insulating particle being exposed to the surface of the charging member and forms a convex portion on the surface of the charging member, in an orthogonal projection image of which the concave portions and the insulating particle are projected on a surface of the electro-conductive support, a site in which an outer edge of a projection image derived from the insulating particle and an outer edge of a projection image derived from each of the concave portions are separated, exists, and a part of a wall of each of the concave portions constitutes a part of the surface of the charging member.

Charging member with concave portions containing insulating particles and electrophotographic apparatus

Provided a charging member including an electro-conductive support and a surface layer, the surface layer having in an outer surface thereof, concave portions and holding an elastic particle in each of the concave portions, the elastic particle being exposed at a surface of the charging member to form a convex portion in the surface of the charging member, and a part of a wall of each of the concave portions constituting a part of the surface of the charging member.

Charging member having outer surface with concave portions bearing exposed elastic particles, and electrophotographic apparatus

Provided is a charging member capable of suppressing adhesion of smear on its surface and suppressing generation of a C set image as well. The charging member includes: an electroconductive support; and an elastic layer as a surface layer, in which: the elastic layer has at least one local maximum value in a distribution of Young's modulus at respective positions in a depth direction thereof; and 'a', 'Tmax' and &#x201c;b&#x201d; satisfy the following expressions (1) to (3): (1) 0.8 &#x3bc;m&#x2266;Tmax&#x2266;2.5 &#x3bc;m, (2) 0.6 MPa&#x2266;b&#x2266;1.2 MPa, (3) (a&#x2212;b)/b&#x2267;0.40.

Charging member, manufacturing method for charging member, electrophotographic apparatus, and process cartridge

Provided is a charging member capable of stably charging an object to be charged while suppressing adhesion of toner or an external additive onto a surface of an elastic layer and compression set of an abutting portion of the elastic layer. The charging member is a charging member, comprising a mandrel; and an electro-conductive elastic layer, wherein: the elastic layer has a universal hardness decreasing from a surface toward a depth direction thereof; and the hardnesses at a central portion and both end portions in a longitudinal direction of the charging member satisfy the relationships: in the surface of the elastic layer, the hardnesses at the both end portions are higher than that at the central portion; and at a position having a depth of t (&#x3bc;m) from the surface of the elastic layer, the hardness at the central portion is higher than those at the both end portions.

Charging member, electrophotographic apparatus, and process cartridge

To provide a charging member that can not easily cause faulty cleaning. A charging member having a conductive support and an elastic layer that is a surface layer; the elastic layer having on its surface a region having been cured by irradiation with electron rays, where the region having been cured supports at least one type of spherical particles of spherical silica particles, spherical alumina particles and spherical zirconia particles in such a state that the spherical particles are exposed at least in part to the surface of the elastic layer so as to make the surface roughened.

Charging member, process for its production, and electrophotographic apparatus

A charging member having a support, a conductive elastic layer formed on the support and a surface layer formed on the conductive elastic layer, wherein the surface layer contains a polysiloxane having an acrylic group and an oxyalkylene group. This provides a charging member to the surface of which toners and external additives used in the toners can not easily cling even because of repeated use over a long period of time and which therefore enables charging and image reproduction which are stable over a long period of time, even when used in the DC contact charging method; and further provides a process cartridge and an electrophotographic apparatus which have such a charging member.

Charging member, process cartridge, and electrophotographic apparatus

An object of the present invention is to provide a charging member in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method, and a process cartridge and an electrophotographic apparatus having the charging member. The present invention provides a charging member comprising a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

Charging member, process cartridge and electrophotographic apparatus

A charging member has a surface layer. The surface layer contains a polysiloxane having a first unit, a second unit and a third unit each of which is represented by a specific formula. The ratio of the sum of the mole numbers of the first and second units to the sum of the mole numbers of the first to third units is in a specific range.

A charging member is provided in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method. Also provided are a process cartridge and an electrophotographic apparatus having the charging member. The charging member includes a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

An interpolation or smoothing filter circuit for a switched-capacitor system which transforms the sampled-and-held output signals from a switched-capacitor filter into sampled-and-held signals with a doubled sample rate. The circuit comprises an operational amplifier whose noninverting input lead is connected to a switched capacitor network which receives the sampled-and-held input signals at the normal sample rate. The network includes two separate capacitors controlled by switches operable at two alternating clock phases and connected to provide the desired summation and holding of charges. Feedback leads connected between the amplifier output lead and its noninverting input lead and containing additional capacitors cooperate with the input network to produce an output signal that is sampled-and-held at twice the sample rate of the input signal.

Growing community of inventors

Gotemba, Japan

Toshiro Suzuki