Canon Kabushiki Kaisha

Tomohito Ishida

Takeshi Ikeda

Takeshi Yamamoto

Takeshi Murakami

Hiroyuki Watanabe

Isami Itoh

Nobuhiro Nakamura

Yasukazu Ayaki

Michiyo Sekiya

Kaname Watariguchi

Tetsuya Atsumi

Tatsuya Yamaai

Shuhei Iwasaki

Masataka Kawahara

Shuntaro Watanabe

Yukio Nagase

Nobuyuki Itoh

Kohei Makisumi

Masatsugu Toyonori

Yuka Ishiduka

Yota Ito

Nobuyuki Ito

Koichi Hashimoto

Kenichi Kaku

Kenta Kubo

Shunichi Takada

Fumiyuki Hiyama

Masatada Hirota

Manami Haraguchi

Tatsuya Tada

Tomoaki Miyazawa

Shuji Moriya

Megumi Uchino

Juun Horie

Hirokazu Usami

Kazuko Araki

In an electrophotographic photosensitive member, wrinkles have a convex portion in which a linear shape portion having a length of 50 μm or longer exists, the linear shape portion is parallel to any one of L1 to L150 and L1651 to L1800, and each of L1 to L1800 intersects with the convex portion at a plurality of places, and at least two of the places have different intersection angles; and when height information of the wrinkles is subjected to a frequency analysis, and a two-dimensional power spectrum is obtained, a one-dimensional radial distribution function has at least one local maximum value, and when an angular distribution is calculated from the spectrum at a frequency of the local maximum value, the power values have a particular relationship.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

Provided is an electrophotographic photosensitive member that achieves satisfactory transferability. An electrophotographic photosensitive member including a charge generating layer, a charge transporting layer, and a protection layer laminated on a support in the stated order, wherein the protection layer contains a binder resin and particles, and wherein when an average thickness of the protection layer in a site free of the particles is represented by T and a volume-average particle diameter of the particles is represented by Dm in a cross-section of the protection layer, the following formula (a) is satisfied.  Formula(a)

The electrophotographic photosensitive member includes a support and a photosensitive layer on the support, in which a surface layer of the electrophotographic photosensitive member contains a particle, the surface layer has a particle partially exposed from the surface layer among the particle contained in the surface layer, the particle has a volume average particle diameter of 50.0 nm or more and 350.0 nm or less; in a cross-section of the surface layer, the number of the particle partially exposed from the surface layer is 80% by number or more based on a total number of the particle contained in the surface layer; and a total volume of an exposed portion of the particle partially exposed from the surface layer is 30% by volume or more and 80% by volume or less based on an entire volume of the particle contained in the surface layer.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

There is provided an electrophotographic photosensitive member having drum shape, the electrophotographic photosensitive member including a support and a photosensitive layer, wherein an outer surface of the electrophotographic photosensitive member has wrinkles, and when an observation region having square form with one side of 100 μm is placed at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a first reference line L1, and 3,599 reference lines obtained by rotating the first reference line L1 at every 0.1° around the central point are defined as L2 to L3,600, respectively, each of L1 to L3,600 intersects with convex portions of the wrinkles at a plurality of locations and has at least two different intersection angles selected from the plurality of locations.

Electrophotographic photosensitive member

A method for producing an electrophotographic photosensitive member including: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer having an amount of residual solvent of a first solvent in the photosensitive layer of 0.05% to 2.50% and an amount of residual solvent of a second solvent in the photosensitive layer of 0.50% to 2.50%, and the step of forming the protective layer includes step (A) of forming a cured film and step (B) of forming the protective layer having wrinkle shapes, wherein, in step (A), the irradiated coating film is heated at a heating temperature lower than a boiling point of the first solvent and in step (B), the cured film is heated at a heating temperature higher than a boiling point of the first solvent.

Method for producing electrophotographic photosensitive member

A process cartridge including: an electrophotographic photosensitive member having a drum shape; a developing unit for developing an electrostatic latent image on the surface of the electrophotographic photosensitive member with toner; and a cleaning blade for removing the toner on the surface of the electrophotographic photosensitive member, the cleaning blade being in contact with the electrophotographic photosensitive member, wherein the electrophotographic photosensitive member comprises wrinkles on the surface of the electrophotographic photosensitive member, and wherein the toner has a fluidity torque E of 320 mJ or more.

Process cartridge

Provided is an electrophotographic photosensitive drum that achieves both of a reduction in torque of the electrophotographic photosensitive drum at the time of its cleaning and an improvement in image transferability. The electrophotographic photosensitive drum includes: a support; and a photosensitive layer arranged on the support, the electrophotographic photosensitive drum having arranged on an outer surface thereof at least two structure groups having different appearance periods, wherein when, out of the two structure groups, a group including structures having a smaller appearance period is defined as a first structure group, and a group including structures having a larger appearance period is defined as a second structure group, a height of the first structure group is lower than a height of the second structure group.

Electrophotographic photosensitive member having outer surface with first and second structure groups, the first structure group having a smaller appearance period and a lower height than the second structure group

The electrophotographic photosensitive member has: a cylindrical support; a charge generating layer formed on the cylindrical support; and a charge transport layer formed on the charge generating layer, the charge generating layer contains a hydroxygallium phthalocyanine crystal having a particular CuK&#x3b1; characteristic X-ray diffraction peak, a titanyl phthalocyanine crystal having a particular CuK&#x3b1; characteristic X-ray diffraction peak or a chlorogallium phthalocyanine crystal having a particular spectral absorption spectrum as a charge generating material, and in the charge generating layer, with respect to the film thickness of the charge generating layer, when a region from the central position of an image forming area to the end position of the image forming area is divided in the axial direction of the cylindrical support into five equal regions and the average film thickness of the charge generating layer in each region satisfies a specific condition.

Provided is an electrophotographic photosensitive member which enables a reduction in unevenness in distribution of the post-exposure potential of the photosensitive member and a reduction in unevenness in life of the photosensitive member in the axial direction. An electrophotographic photosensitive member, including a cylindrical support, a charge generating layer, and a charge transport layer in this order, wherein when a region from a central position of an image formation region of the electrophotographic photosensitive member to an end position of the image formation region in the axial direction of the cylindrical support is equally divided into five regions, average film thicknesses of the charge generating layer in the five regions satisfy specific relations in a film thickness of the charge generating layer and average film thicknesses of the charge transport layer in the five regions satisfy specific relations in a film thickness of the charge transport layer.

An electrophotographic photosensitive member, including a cylindrical support, a charge generating layer formed on the cylindrical support, and a charge transport layer formed on the charge generating layer, in which in the charge generating layer, when a region from a central position of an image forming region to an end position of the image forming region in an axis direction of the cylindrical support is divided equally into five regions, film thicknesses of the charge generating layers in each of the regions satisfy a specific relationship with each other, and in the charge transport layer, when a region from the central position of the image forming region to the end position of the image forming region in the axis direction of the cylindrical support is divided equally into five regions, film thicknesses of the charge transport layers in each of the regions satisfy a specific relationship with each other.

Provided is an electrophotographic photosensitive member in which discharge streaks generated in an end portion can be suppressed. The electrophotographic photosensitive member includes a cylindrical support, a charge-generating layer, and a charge-transporting layer in the stated order. In the electrophotographic photosensitive member, when a region between a center position and a 90% position situated at a 90% of a length of from the center position to one end of the electrophotographic photosensitive member in an axial direction thereof from the center position, is defined as a region X, and a region between the 90% position and the end of the electrophotographic photosensitive member is defined as a region Z. Average thicknesses in regions obtained by equally dividing the region X into five and regions obtained by equally dividing the region Z into three satisfy particular relationships.

An electrophotographic photosensitive member includes an electroconductive support member and a photosensitive layer. The uppermost layer of the electrophotographic photosensitive member defines a surface layer, and the surface layer contains polytetrafluoroethylene particles, a charge transporting material, and polyvinyl acetal. The proportion of the polyvinyl acetal content to the polytetrafluoroethylene particles content in the surface layer is in the range of 0.1% by mass to 15.0% by mass, and the charge transporting material content in the surface layer is 35% by mass or more relative to the total mass of the surface layer.

An image forming apparatus that can reduce a toner bearing amount stably regardless of a density of an image. The image forming apparatus comprises a first generating unit which generates a reference pattern, and a second generating unit which generates, based on image data, a correction pattern for thinning out dots at a region from halftone density to high density. The image data is converted based on the reference pattern generated by the first generating unit and the correction pattern generated by the second generating unit. The image forming apparatus further comprises a photoreceptor. The photoreceptor is charged, the charged photoreceptor is exposed based on the converted image data to form an electrostatic latent image, and the electrostatic latent image is developed.

Image forming apparatus and image forming method for reducing toner bearing amount, and storage medium thereof

A developing device includes a developing member and a carrier collecting member. An outer surface of the developing member includes a plurality of protrusion portions aligned at regular intervals that are equal to or larger than an average particle diameter of toner particles and smaller than an average particle diameter of magnetic carrier particles. Each protrusion portion has a first face formed at one side of an apex of each protrusion portion and a second face formed at the other side of the apex, and an inclination angle of the first face is less than an inclination angle of the second face. In the circumferential direction of the developing member, when a downward direction of the first face is set to be positive, a relative velocity of a surface velocity of an image bearing member to a surface velocity of the developing member is set to be positive.

Image forming apparatus

An image forming apparatus includes a photosensitive member, a first developer carrying member for carrying a developer comprising toner and a carrier for developing an electrostatic image formed on the photosensitive member, and a second developer carrying member for carrying the developer received from the first developer carrying. The second developer carrying member is disposed downstream of the first developer carrying member with respect to a rotational direction of the photosensitive member. In addition, a voltage source applies a developing bias voltage to the first developer carrying member and second developer carrying member, and a driving device rotates the first developer carrying member at a peripheral speed higher than that of the photosensitive member and rotates the second developer carrying member at a peripheral speed which is higher than that of the photosensitive member and which is lower than that of the first developer carrying member.

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Suntou-gun, Japan

Tomohito Ishida