Canon Kabushiki Kaisha

Kyoichi Teramoto

Harunobu Ogaki

Akira Shimada

Masataka Kawahara

Akio Maruyama

Toshihiro Kikuchi

Atsushi Ochi

Hiroki Uematsu

Takayuki Sumida

Akio Koganei

Takashi Anezaki

Yoichi Kawamorita

Yasuhiro Kawai

Hirotoshi Uesugi

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

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.

A measuring method of a shape of a cross-sectional circle which is orthogonal to an axis of a cylinder includes steps of calculating distances between a reference point and points on a circumference on the basis of change of the distances of at least three predetermined points on the circumference of the cross-sectional circle to the reference point set in the cross-sectional circle by the rotation of the cylinder, and specifying the shape of the cross-sectional circle.

Growing community of inventors

Abiko, Japan

Kyoichi Teramoto