Abstract: A developing device includes: a housing that stores toner therein; a toner carrying roller that is attached to the housing by a shaft and is rotated in a predetermined rotation direction while carrying charged toner on a surface of the toner carrying roller to transport the toner to the outside of the housing; and a seal member that extends in a direction of a rotation axis of the toner carrying roller and has one end fixed to the housing and the other end in contact with the surface of the toner carrying roller to prevent the toner from leaking out of the housing, wherein a plurality of convex portions having top surfaces constituting a part of the same cylindrical surface are formed on the surface of the toner carrying roller, and at least a part of the seal member in contact with the surface of the toner carrying roller is made of a material having a contact angle of 105° or more with respect to water.

Abstract: A method of manufacturing a toner carrier roller that is shaped like a cylinder on an outer circumferential surface of which concave and convex sections for carrying toner are provided, includes: preparing a roller base member which is shaped like a cylinder; forming helix-like first grooves on the outer circumferential surface of the roller base member; and forming helix-like second grooves, which cross the first grooves, on the outer circumferential surface of the roller base member, wherein a pitch ratio of the first grooves and the second grooves is a non-integer ratio.

Abstract: A developing device, includes: a housing that stores toner inside; a toner carrier roller that is shaped approximately like a cylinder, is mounted to the housing rotatably about a rotational axis, rotates while carrying the toner on a surface thereof to convey the toner to outside of the housing, and is provided, on the surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, the convex sections including top surfaces that coincide with a part of a curved surface of single cylinder and have electrical conductivity; and a seal member that is arranged in abutting contact with the surface of the toner carrier roller moving from the outside the housing toward the inside the housing at a position downstream of the opposed position in a rotation direction of the toner carrier roller to prevent toner leakage from the housing, a contact surface of the seal member being made of a material located at a position to charge the toner with

Abstract: A developing device includes a container that contains toner particles that are for developing a latent image borne by an image bearing body, and a toner-particle bearing roller that has a helical groove portion on a surface thereof that is for bearing the toner particles, the helical groove portion having an inclination with respect to an axial direction and a circumferential direction of the toner-particle bearing roller and being formed having a uniform pitch in the axial direction.

Abstract: An image forming apparatus, includes: a latent image carrier that carries an electrostatic latent image; a housing that stores toner inside; a toner carrier roller that is shaped approximately like a cylinder, is mounted to the housing rotatably about a rotational axis, rotates while carrying toner on a surface thereof to convey the toner to an opposed position facing the latent image carrier outside the housing, and is provided, on the surface thereof, with a plurality of convex sections which are regularly arranged in an axial direction parallel to the rotational axis and in a circumferential direction orthogonal to the axial direction and parallel to a circumferential surface of the toner carrier roller and a concave section which surrounds the convex sections; a seal member that is arranged in abutting contact with the surface of the toner carrier roller moving from the outside the housing toward the inside the housing at a position downstream of the opposed position in a rotation direction of the toner c

Abstract: An image forming apparatus includes: an image bearing body that is rotatable about a central axis thereof, and that bears a dot-like latent image, on a surface of the image bearing body, in each of a plurality of divided regions that are arranged in rows along a direction that intersects an axial direction of the central axis at a predetermined intersection angle; and a developer bearing roller that is rotatable in order to make visible, as a developer image, the dot-like latent images borne by the image bearing body, using a developer borne on a surface of the developer bearing roller, the developer bearing roller opposing the image bearing body such that an axial direction of the developer bearing roller is parallel to the axial direction of the image bearing body, and that includes a helical groove portion on the surface of the developer bearing roller, the helical groove portion being inclined at a predetermined inclination angle with respect to the axial direction of the developer bearing roller and bein

Abstract: The invention provides, as an aspect thereof, an image formation apparatus that includes: an image carrier that carries a latent image; a toner carrier that has, on a surface of the toner carrier, a concave portion arrayed in a regular pattern so as to carry toner, and develops the latent image that is carried on the image carrier by means of the toner carried in the concave portion; and a voltage application section that applies a development voltage to the toner carrier for the purpose of the development of the latent image. In the configuration of an image formation apparatus according to the above-described aspect of the invention, immediately after that the toner carrier has developed the latent image, which is carried on the image carrier, by means of the toner carried in the concave portion in response to the application of the development bias to the toner carrier by the voltage application section, at least one layer of the toner remains carried in the concave portion.

Abstract: An image forming apparatus includes an image bearing body and a developer bearing body. A transferring section transfers, onto a medium, a developer image formed on the image bearing body by development of the latent image. A voltage applying section alternately applies, to the developer bearing body, a first voltage for making the developer move from the developer bearing body toward the image bearing body in order to develop the latent image, and a second voltage for making the developer move from the image bearing body toward the developer bearing body. An image darkness adjusting section adjusts a darkness of the image to be formed on the medium by changing only the second voltage.

Abstract: An image forming apparatus includes: an image bearing body that is rotatable about a central axis thereof, and that bears a dot-like latent image, on a surface of the image bearing body, in each of a plurality of divided regions that are arranged in rows along a direction that intersects an axial direction of the central axis at a predetermined intersection angle; and a developer bearing roller that is rotatable in order to make visible, as a developer image, the dot-like latent images borne by the image bearing body, using a developer borne on a surface of the developer bearing roller, the developer bearing roller opposing the image bearing body such that an axial direction of the developer bearing roller is parallel to the axial direction of the image bearing body, and that includes a helical groove portion on the surface of the developer bearing roller, the helical groove portion being inclined at a predetermined inclination angle with respect to the axial direction of the developer bearing roller and bein

Abstract: A method for manufacturing a developing agent carrier of a hollow or solid cylindrical shape having an outer peripheral surface and an irregularity section formed on the outer peripheral surface to carry a developing agent is provided. The method comprises a step of preparing a base material of a hollow or solid cylindrical shape which is to become the developing agent carrier, the base material having an outer peripheral surface; and a step of forming the irregularity section by pressing dice for formation of the irregularity section against the outer peripheral surface of the base material.

Abstract: A developing device includes a toner particle-bearing roller that bears toner particles on its surface and develops a latent image borne by an image-bearing member with those toner particles, the toner particle-bearing roller has a projection portion disposed on its surface, the projection portion having a top surface having a flat portion, and a width of the top surface being equal to or more than a volume average particle diameter of the toner particles.

Abstract: A developing device includes a container that contains toner particles that are for developing a latent image borne by an image bearing body, and a toner-particle bearing roller that has a helical groove portion on a surface thereof that is for bearing the toner particles, the helical groove portion having an inclination with respect to an axial direction and a circumferential direction of the toner-particle bearing roller and being formed having a uniform pitch in the axial direction.

Abstract: An image forming apparatus includes: an image bearing body for bearing a latent image; a developer bearing body that bears a developer and that is for developing the latent image borne on the image bearing body with the developer; a transferring section that transfers, onto a medium, a developer image formed on the image bearing body by the development of the latent image, to form an image; a voltage applying section that alternately applies, to the developer bearing body, a first voltage for making the developer move from the developer bearing body toward the image bearing body in order to develop the latent image, and a second voltage for making the developer move from the image bearing body toward the developer bearing body; and an image darkness adjusting section for adjusting a darkness of the image to be formed on the medium by changing only the second voltage, among the first voltage and the second voltage.