Canon Kabushiki Kaisha

Akio Maruyama

Toshihiro Kikuchi

Hiroki Uematsu

Shoji Amamiya

Akira Shimada

Kazushige Nakamura

Shin Nagahara

Michiyo Sekiya

Harunobu Ogaki

Masataka Kawahara

Atsushi Ochi

Takayuki Sumida

Noriko Ohtani

Akio Koganei

Kyoichi Teramoto

Koichi Nakata

Teigo Sakakibara

Tatsuya Ikezue

Noboru Kashimura

Shuji Ishii

Takahiro Mitsui

Tohru Den

Shuzo Kaneko

Keishi Saito

Yuichi Hashimoto

Tatsuo Takeuchi

Harumi Ishiyama

Masao Sugata

Hideki Anayama

Yoshihiro Oguchi

Ryoji Fujiwara

Keiji Hirabayashi

Susumu Ito

Hisami Tanaka

Hiroshi Satomura

Haruyuki Tsuji

Tomoko Maruyama

Takakazu Tanaka

Shinya Mayama

Noriko Kurihara

Keiko Ikoma

Kuniji Osabe

Tomoko Murakami

Koichi Suzuki

Hiroyuki Tanaka

Kiyoshi Sakai

Tsutomu Kukimoto

Yukio Nagase

Hideyuki Yano

Katsumi Aoki

Takashi Anezaki

Yomishi Toshida

Waka Hasegawa

Naoto Fujimura

Shuichi Aita

Tadashi Furuya

Hirotoshi Uesugi

Yoshifumi Hano

Hiroyuki Ohmori

Junichi Kishi

Seiko Nakano

Masami Okunuki

Masaaki Yamagami

Noriyuki Takagi

Harumi Sako

Toshiro Kikuchi

Syoji Amamiya

External additive particles including a polymer containing a sulfur atom and a nitrogen atom, wherein the polymer includes a vinyl polymer moiety and a siloxane moiety, relative to a total number of carbon atoms, oxygen atoms, and silicon atoms constituting the external additive particles, a ratio of a number of the silicon atoms constituting the external additive particles is 4.0% or more and 25.0% or less, and in surfaces of the external additive particles analyzed by X-ray photoelectron spectroscopy, relative to a total number of carbon atoms, nitrogen atoms, oxygen atoms, silicon atoms, and sulfur atoms, a ratio of a number of the nitrogen atoms is 0.40% or more and 2.50% or less, and a ratio of a number of the sulfur atoms is 0.05% or more and 0.25% or less.

External additive particles, toner, and method for producing external additive particles

An image forming method is disclosed having a charging step, an exposure step, a developing step and a transfer step. This method uses a toner which includes toner particles containing a binder resin and a colorant, and inorganic fine powder, and uses a photosensitive member which has on its surface depressed portions which are independent of one another. The depressed portions have openings having an average minor-axis diameter Lpc satisfying the relationship of Dg&#x3c;Lpc&#x3c;Dt (Dt represents the weight-average particle diameter of the toner, and Dg represents the maximum number-average particle diameter among number-average particle diameter(s) of one or two or more types of inorganic fine powder constituting the inorganic fine powder, and the toner has an average circularity of from 0.925 to 0.995.

Image forming method, and electrophotographic apparatus making use of the image forming method

An electrophotographic photosensitive member is disclosed which is excellent in cleaning performance, has improved durability, and suppresses image defects in various environments. The electrophotographic photosensitive member has a support and a photosensitive layer provided on the support. Depressed portions independent of one another are formed on the surface of the electrophotographic photosensitive member so that the number of the depressed portions per 100 &#x3bc;m square is 76 or more and 1,000 or less. The openings of the depressed portions have an average major axis diameter of more than 3.0 &#x3bc;m and 14.0 &#x3bc;m or less.

Electrophotographic photosensitive member with depressed portions, process cartridge holding the electrophotographic photosensitive member and electrophotographic apparatus with the electrophotographic photosensitive member

A process for producing an electrophotographic photosensitive member, which has the step of bringing i) the surface of an electrophotographic photosensitive member having at least a charge transport layer on a cylindrical support and ii) a mold having a fine unevenness surface profile into pressure contact with each other to transfer the fine unevenness surface profile to the surface of the electrophotographic photosensitive member. The mold and the support are so temperature-controlled as to be T&#x3c;T&#x3c;Twhere the glass transition temperature of the charge transport layer is represented by T(&#xb0;C.), the temperature of the mold by T(&#xb0;C.), and the temperature of the support by T(&#xb0;C.).

Process for producing electrophotographic photosensitive member

A process for making an electrophotographic photosensitive member is provided by forming a photosensitive layer on an electroconductive support. The photosensitive layer is provided with particularly excellent durability while retaining good electrophotographic performances when formed as a layer comprising a polymerizate of a hole-transporting compound having at least two chain polymerization function groups in its molecule represented by formula (1) below:(PAzP))&#x2003;&#x2003;(1),wherein A denotes a hole-transporting group, Pand Pindependently denote a chain polymerization function group and Z denotes a bonding organic group; a, b and d are independently an integer of at least 0 satisfying a+b&#xd7;d&#x2267;2 provided that if a&#x2267;2, plural groups Pcan be identical or different; if b&#x2267;2, plural groups Z can be identical or different; and if b&#xd7;d&#x2267;2, plural groups Pcan be identical or different.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An electrophotographic photosensitive member has a surface having a plurality of depressed portions, having a major-axis diameter Rpc of 0.1 to 10 &#x3bc;m, a minor-axis diameter Lpc of 0.1 to 10 &#x3bc;m and a deepest-part to opening distance Rdv of 0.1 to 10 &#x3bc;m. Where the surface is equally divided into 4 regions in the rotational direction, which are then equally divided into 25 regions in the direction falling at right angles with the rotational direction, to obtain 100-spot regions A in total, and, in each thereof, square regions B of 50 &#x3bc;m each per side one side of which is parallel to the rotational direction are provided and the regions B are each equally divided into 500 zones by straight lines parallel to the rotational direction, 400 to 499 lines among the straight lines pass through the depressed portions in each of the regions B.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

An electrophotographic photosensitive member has, on the surface of its photosensitive layer, has a plurality of depressed portions which are independent from one another, and, where the major-axis diameter of each depressed portion is represented by Rpc and the depth that shows the distance between the deepest part of each depressed portion and the opening thereof is represented by Rdv, the depressed portions each have a ratio of depth to major-axis diameter, Rdv/Rpc, of from more than 1.0 to 7.0 or less.

An electrophotographic photosensitive member hard to cause the problem of chatter and wear-out of the cleaning blade and the problem of a rubbing memory, and both a process cartridge and an electrophotographic apparatus having the photosensitive member are provided. The peripheral surface of the photosensitive member has a plurality of dimple-shaped concaves, a 10-point average roughness Rzjis (A) as measured by sweeping along the circumference of the peripheral surface of the photosensitive member is 0.3 to 2.5 &#x3bc;m, a 10-point average roughness Rzjis (B) as measured by sweeping along the generating line of the peripheral surface of the photosensitive member is 0.3 to 2.5 &#x3bc;m, a mean spacing of profile irregularities, RSm (C), as measured by sweeping along the circumference of the peripheral surface of the photosensitive member is 5 to 120 &#x3bc;m, a mean spacing of profile irregularities, RSm (D), as measured by sweeping along the generating line of the photosensitive member is 5 to 120 &#x3bc;m, and the value of a ratio (D/C) of the mean spacing of profile irregularities RSm (D) to the mean spacing of profile irregularities RSm (C) is 0.5 to 1.5.

Electrophotographic Photosensitive member, method for manufacturing electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An object of the present invention is to improve a phenomenon of the life-shortening of the endurance life due to scratch occurring when recesses of a fixed dimple shape are formed on the surface of the surface layer, in order to inhibit the chattering and folding back of a cleaning blade and the fracture of an edge, which occurs because friction between the surface layer of the surface of an electrophotographic photosensitive member and an abutting member is high; and particularly to improve the above described problems, from initial printing through printing on many sheets, which become particularly remarkable when using an electrophotographic photosensitive member with the use of a curable resin that is improved so as to have a high elastic deformation rate for the surface layer, in order to improve the strength of the surface layer, for the purpose of increasing the durability of an electrophotographic photosensitive member. An electrophotographic photosensitive member for achieving the object, which has a support and an organic photosensitive layer, is characterized in that the electrophotographic photosensitive member has dimple-shaped concavities formed on the surface of the surface layer of the electrophotographic photosensitive member, and further has the recesses with the same pattern as that on the surface of the surface layer, formed on the interface created between the surface layer of the organic photosensitive member and the layer directly under the surface layer (a subsurface layer).

Electrophotographic photosensitive member, method for manufacturing electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An electrophotographic photosensitive member is disclosed having a cylindrical support and an organic photosensitive layer provided on the cylindrical support. The peripheral surface of the electrophotographic photosensitive member is composed of grooves formed substantially in its peripheral direction and flat portions, and in the grooves, the number of grooves each having a width in the range of from 0.5 &#x3bc;m to 40 &#x3bc;m is from 20 to 1,000 lines per 1,000 &#x3bc;m in width in the generatrix direction of the peripheral surface of the electrophotographic photosensitive member.

Electrophotographic photosensitive member, electrophotographic photosensitive member manufacturing process, process cartridge, and electrophotographic apparatus

An electrophotographic photosensitive member is constituted by disposing a protective layer and a photosensitive layer on an electroconductive support in this order. The protective layer is characterized by containing an electroconductive particles, fluorine-containing resin particles and a binder resin. The photosensitive layer is suitable for providing an electrophotographic apparatus showing excellent electrophotographic characteristics such as a high photosensitivity and a low residual potential and also providing good image forming properties under any environmental condition, improved pause memory characteristics and a decreased transfer memory.

Electrophotographic photosensitive member electrophotographic apparatus using same and device unit using same

An electrophotographic photosensitive member has a support and a photosensitive layer formed thereon. The electrophotographic photosensitive member has a surface layer containing a charge-transporting material and a resin obtained by exposing to radiations a compound having an acryloyloxy group or methacryloyloxy group to cure.

ELECTROPHOTOGRAPHIC PHOTOSENSITVE MEMBER, PROCESS FOR PRODUCING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, AND PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS WHICH HAVE THE ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

An electrophotographic apparatus includes an electrophotographic photosensitive member; a charger for charging the electrophotographic photosensitive member including a charging member supplied with a voltage and disposed in contact with the photosensitive member so as to form a nip with the photosensitive member to charge the photosensitive member; an exposure device; a developing device; and a transfer device. The photosensitive member includes a surface layer containing a charge-transporting material having an oxidation potential of 0.4-1.0 volt. Charging promoter particles are present at the nip between the photosensitive member and the charging member to injection-charge the photosensitive member. Because of the selection of the charge-transporting material and the presence of the charging promoter particles, the photosensitive member can be effectively injection-charged.

Electrophotographic apparatus and process cartridge

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Tokyo, Japan

Akio Maruyama