Abstract: An image forming apparatus includes: an image carrier; an exposure device; a developing device that develops the latent image on the image carrier by using a toner charged to a predetermined polarity and having an external additive; a transfer device that transfers a toner image developed on the image carrier to a transfer medium; a first charging member that charges the external additive and the transfer residual toner remaining on the image carrier and the image carrier after transfer to the same polarity as a polarity of the toner; a cleaning member that electrostatically attracts the external additive and the transfer residual toner charged by the first charging member; and a second charging member that charges the image carrier to an electric potential smaller in absolute value than an electric potential of the image carrier generated after the image carrier passes the cleaning member.

Abstract: A method of manufacturing a developing roller, including: a first rolling process for forming a first inclined groove which is continuous in a helical shape, by rotating a first die having blades inclined with respect to an axial direction and a circumferential direction, and a non-bladed die, and feeding an unprocessed developing roller between the first die and the non-bladed die; and a second rolling process for forming a second inclined groove which is continuous in a helical shape and intersects with the first inclined groove, by rotating a second die having blades inclined with respect to an axial direction and a circumferential direction in the direction opposite to that of the first die, and the non-bladed die in the same direction opposite to that in the first rolling process, and feeding the developing roller between the second die and the non-bladed die.

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: An image forming method and apparatus in which a protective agent is supplied to an image carrier, and the image carrier is charged by a plurality of charging units. Degrees of discharge deterioration of the surface of the image carrier in the plurality of charging units are different, and the amount of protective agent supplied to a charging portion of a charging unit, in which a degree of discharge deterioration of the surface of the image carrier is high, is large.

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 toner, has a number mode diameter of 3 ?m or more and 6 ?m or lower and a particle size distribution of a toner including an externally-applied agent in the range of 0.6 ?m to 400 ?m in which the number frequency of a toner smaller than the number mode diameter is smaller than the number frequency of a toner equal to or larger than the number mode diameter.

Abstract: Provided is an image forming apparatus including: a rotatable image carrier; a protective agent supplying unit supplying a protective agent to the image carrier; a first charging unit charging the image carrier to the same polarity as a regular charging polarity of a toner; a second charging unit charging the protective agent supplied to the image carrier to the opposite polarity to the regular charging polarity of the toner; an exposure unit forming an electrostatic latent image on the image carrier; a development unit developing the electrostatic latent image of the image carrier; and a transfer unit transferring the image of the image carrier, wherein the second charging unit is disposed between the protective agent supplying unit and the development unit.

Abstract: An image forming apparatus includes: a latent image holder that holds on its surface an electrostatic latent image in which an image portion and a non-image portion have different potentials; a toner carrying roller that carries a toner layer including both contact toner which directly contacts a surface of the roller and non-contact toner which contacts the contact toner but does not contact the surface of the roller; and an electric field forming unit that forms an alternating electric field to cause an electric field strength exerted between the non-image portion on the surface of the latent image holder and the surface of the toner carrying roller to be lower than a contact toner fly start electric field strength and higher than a non-contact toner fly start electric field strength, between the latent image holder and the toner carrying roller, as a toner fly electric field.

Abstract: The present invention provides a developing device that includes a toner bearing member that includes regularly arranged projection sections and depressed sections for bearing toner, and that develops a latent image borne on an image bearing member with the toner borne on the projection sections and the depressed sections, wherein the latent image is developed in a state in which a projection section covering ratio at which toner contacting the projection sections covers the projection sections is smaller than a depressed section covering ratio at which toner contacting the depressed sections covers the depressed sections.

Abstract: A development roller includes a base unit having a base recess and a base projection formed in a predetermined area of a circumference surface of the base unit, and a surface layer formed on the circumference surface of the base unit and having a recess and a projection formed respectively in accordance with the base recess and the base projection of the base unit.

Abstract: Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit; a transferring unit; and a cleaning unit, wherein a voltage of the non-image portion of the latent image carrier is Vo, a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the latent image carrier to the toner carrier is maximum is Vmax, and a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the toner carrier to the latent image carrier is maximum is Vmin, in the developing position, an equation |Vmax?Vo|>|Vmin?Vo| is satisfied.

Abstract: A developer apparatus, includes: a container which houses toner; a toner carrier roller that is provided, on a surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, is shaped approximately like a cylinder, and rotates while carrying a toner layer of charged toner supplied from the container on the surface thereof, and a restriction member that abuts on the surface of the toner carrier roller to form a restriction nip, restricts a thickness of the toner layer carried on the surface of the toner carrier roller in the restriction nip, and removes the toner layer on the convex sections from among the toner layer carried on the surface of the toner carrier roller at an upstream-side end of the restriction nip in a rotation direction of the toner carrier roller.

Abstract: A developer apparatus includes a toner carrier roller with plural rows of convex sections arranged in width and circumferential directions of the roller. Top surfaces of the convex sections coincide with a curved surface of a single cylinder shaped like the roller. Convex section extending surfaces obtained by extending the top surfaces of the convex sections in the width direction overlap between convex sections belong to the same row and do not overlap between convex sections belonging to different rows. A width in the circumferential direction of a restriction nip formed by contact of an elastic abutting member of a restriction member with the roller is smaller than a spacing between two convex sections belonging to convex section rows that are adjacent in the circumferential direction.

Abstract: A development roller includes a base unit having a base recess and a base projection that are formed in a predetermined area of a circumference surface of the base unit by pressing a regular pattern in pressure machining, and a surface layer formed on the circumference surface of the base unit and having a recess and a projection formed respectively in accordance with the base recess and the base projection of the base unit. A thickness of the surface layer is larger than a maximum height of a base swollen portion close to the side edge of the base projection from a regular surface of the base projection.

Abstract: A developer apparatus includes a toner carrier roller having convex and concave sections formed thereon. A restriction member including an elastic abutting member having an edge part that abuts the toner carrier roller removes toner from the convex sections such that the concave sections alone carry toner. Within a restriction nip created as the toner carrier roller and the restriction member abut abutting segments where the edge part abuts on the convex sections, and opening segments where the edge part and the concave sections are opposed to each other with a gap between each other, appear alternatingly along the width direction. In the opening segments, the edge part bulges toward bottom surfaces of the concave sections beyond linear lines connecting top surfaces of two adjacent convex sections which are on both sides to the concave sections which are opposed to the edge part.

Abstract: A developer apparatus, includes: a container which houses toner; a toner carrier roller which is provided, on a surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, is shaped approximately like a cylinder, and rotates while carrying a toner layer of charged toner supplied from the container on the surface thereof; and a restriction member which abuts on the toner layer on the surface of the toner carrier roller to restrict a thickness of the toner layer, and restricts the toner layer carried by the convex sections within the surface of the toner carrier roller to one layer or less.

Abstract: A developing device includes: a developing roller on the surface of which intersecting inclined grooves are formed by rolling working; and a seal member which comes into contact with the developing roller, wherein ridge portions of a convex portion surrounded by the inclined grooves of the surface of the developing roller are formed such that rotational resistance due to the contact of the seal member on the downstream side of a rotation direction opposite to a rotation direction of the developing roller at the time of development is larger than rotational resistance due to the contact of the seal member on the downstream side of a rotation direction of the developing roller at the time of development, and at the time of refreshing of the seal member, the developing roller is rotated in the opposite direction to a direction at the time of development.

Abstract: Provided is a development device including: a development roller in which continuous spiraling inclined grooves having different inclinations with respect to an axial direction are formed so as to cross each other; and a feed roller which is in contact with the development roller and feeds toner to the development roller, wherein transportation force, which is used for transporting the toner on the development roller from one side to the other side of the axial direction of the development roller, is generated by the rotation of the feed roller.

Abstract: An image formation apparatus includes an image carrier and a toner carrier having a concave portion arrayed in a regular pattern on its surface. A latent image that is carried on the image carrier is developed by toner carried in the concave portion by applying a development voltage to the toner carrier. After the toner carrier has developed the latent image, at least one layer of toner remains in the concave portion.

Abstract: A development roller includes a base unit having a base recess and a base projection that are formed in a predetermined area of a circumference surface of the base unit, and a surface layer formed on the circumference surface of the base unit and having on the circumference thereof a recess and a projection formed respectively in accordance with the base recess and the base projection of the base unit. Surface hardness of the projection is higher than surface hardness of the recess.