Canon Kabushiki Kaisha

Shuhei Iwasaki

Takeshi Murakami

Hiroyuki Watanabe

Tatsuya Yamaai

Yota Ito

Akira Sakakibara

Kohei Makisumi

Nobuhiro Nakamura

Tomohito Ishida

Jumpei Kuno

Harunobu Ogaki

Yuka Ishiduka

Kazunori Noguchi

Kenichi Kaku

Daisuke Miura

Akihiro Maruyama

Michiyo Sekiya

Shuntaro Watanabe

Kaname Watariguchi

Takumi Furukawa

Hideharu Shimozawa

Yuya Tomomizu

Fumiyuki Hiyama

Satoshi Nishida

Yuji Kawaguchi

Takanori Mitani

Kazunari Hagiwara

Naoki Fukushima

The electrophotographic apparatus includes: an electrophotographic photosensitive member; a charging unit; an image-exposing unit; a charge transfer amount-sensing unit for sensing the amount of charge transferred to the electrophotographic photosensitive member; and an exposed portion potential-controlling unit for controlling the potential of each of the exposed portions of the electrophotographic photosensitive member based on a sensing result, which is obtained by charging the electrophotographic photosensitive member with the charging unit, performing image exposure with the image-exposing unit in at least one light amount weaker than a light amount in which the normalized radius of curvature R of the electrophotographic photosensitive member represented by the following equation (E1), the normalized radius of curvature being obtained by a method of measuring an EV curve, shows a minimum, and in at least two light amounts stronger than the light amount in which the normalized radius of curvature shows the minimum.

Electrophotographic apparatus

An electrophotographic photosensitive member includes: a support; an undercoat layer; a charge generation layer; and a charge transport layer, wherein the undercoat layer contains a polyamide resin and a titanium oxide fine particle, and on the surface of the undercoat layer, an arithmetic mean roughness Ra and an average length Rsm of a roughness curve element both according to JIS B0601:2001 satisfy Ra≤50 nm and 0.1≤Ra/Rsm≤0.5; and the charge generation layer contains a hydroxygallium phthalocyanine pigment, wherein the hydroxygallium phthalocyanine pigment includes crystal particles having a crystal form exhibiting peaks at 7.4°±0.3° and 28.2°±0.3° at Bragg angles 2θ in a spectrum of X-ray diffraction using a CuKα, ray; and in a size distribution of the crystal particles, which is measured using small-angle X-ray scattering, a peak exists in a range of 20 to 50 nm, and the peak has a half-value width of 50 nm or smaller.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

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.

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

Provided is an electrophotographic apparatus including: an electrophotographic photosensitive member; a voltage application unit configured to cause discharge from an electroconductive member to the electrophotographic photosensitive member; a charge transfer amount detection unit configured to detect a charge transfer amount per unit time resulting from the discharge from the electroconductive member to the electrophotographic photosensitive member; and a charging potential control unit, wherein Vand Vdefined by specific procedures for the electrophotographic photosensitive member satisfy a relationship represented by the following expression (E-4): 100V<V−V(E-4), and wherein the charging potential control unit is configured to control the charging potential of the electrophotographic photosensitive member at the time of image formation.

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 present disclosure provides an electrophotographic photosensitive member that can simultaneously achieve the suppression of the occurrence of the black spot in a charged portion and the suppression of the deterioration in sensitivity of an exposed portion, even after stored in a high-temperature and high-humidity environment. An electrophotographic photosensitive member includes an electro-conductive support, an undercoat layer, a charge generation layer and a charge transport layer in this order, wherein an atomic concentration ratio R of the oxygen atom to the aluminum atom on the surface of the electro-conductive support, as measured by energy dispersive X-ray spectroscopy, satisfies the following Expression (1):1.6&#x2264;&#x2003;&#x2003;(1)

An electrophotographic photoreceptor includes a support, an undercoat layer placed on the support, a charge generation layer placed on the undercoat layer, and a charge transport layer placed on the charge generation layer. The undercoat layer contains titanium oxide particles surface-treated with an organosilicon compound that is at least one member selected from the group consisting of compounds represented by formulas (1) to (8) and a polyamide resin. The charge generation layer contains hydroxygallium phthalocyanine.

Electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus

The present disclosure provides an electrophotographic photosensitive member that reduces the accumulation of charge and the leakage which are caused by a repeated use in a long period of time. The electrophotographic photosensitive member has a support, an undercoat layer, a charge generation layer and a charge transport layer in this order, wherein the undercoat layer contains a polyamide resin, and a titanium oxide particle, wherein the titanium oxide particle has been surfacetreated with an organosilicon compound, wherein the undercoat layer satisfies 10&#x2264;&#x3b1;&#x2264;70, where &#x3b1; represents a degree [%] of hydrophobicity of the titanium oxide particle which has been surfacetreated with the organosilicon compound; and the undercoat layer satisfies 0.015&#x2264;(&#x3b2;&#xd7;&#x3b3;)&#x2264;0.040, where &#x3b2; represents an average primary particle size [&#x3bc;m] of the titanium oxide particles, and &#x3b3; represents a weight percentage [wt %] of an Si element of the organosilicon compound with respect to the titanium oxide particle.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Provided is an electrophotographic photosensitive member that is improved in potential stability in long-term use under a high-temperature and high-humidity environment, and does not cause degradation in image quality, such as a low density. The electrophotographic photosensitive member includes: a support; an undercoat layer formed on the support; a charge-generating layer formed directly on the undercoat layer; and a charge-transporting layer formed on the charge-generating layer. The undercoat layer contains a polyamide resin, titanium oxide particles surface-treated with an organic silicon compound, and a compound represented by the following Formula (1), and has a content of the compound represented by the Formula (1) of 4 ppm or more and 80 ppm or less: in the Formula (1), R and R' each independently represent a methyl group or an ethyl group.

Electrophotographic photosensitive member, electrophotographic apparatus, and process cartridge

Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mmor less.

Process cartridge and electrophotographic apparatus

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mmor more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mmor more and 20 N/mmor less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.

Growing community of inventors

Yokohama, Japan

Shuhei Iwasaki