Abstract: A developing unit includes a developing roller which rotates about a rotational axis to supply toner to a photoreceptor, and a magnetic roller which forms a magnetic brush with a two-component developing agent having carrier and the toner and thereby forms a toner layer on the developing roller, the developing roller including: a cylindrical core portion which includes an electric conductor; a first resistive layer which covers a cylindrical surface of the core portion; a second resistive layer which covers the first resistive layer, and has electric-resistivity lower than that of the first resistive layer; and a current leakage control member which prevents leakage of electric current from the core portion toward the second resistive layer through an end of the developing roller along a direction of the rotational axis.

Abstract: A developing device is provided with a developing roller arranged to face a photoconductor for forming an electrostatic latent image and adapted to supply a toner to the photoconductor, an agitating member for agitating a developer, a supply roller that holds the developer agitated by the agitating member, and supplies the toner to an area facing the developing roller; a restricting member for blocking the developer supplied onto the supply roller and restricting the amount of the developer conveyed by the supply roller, and an intermediate roller including a first magnetic pole facing in a direction toward the staying developer by being restricted by the restricting member for attracting the staying developer and arranged at such a position as to face the developer blocked by the restricting member. Thus, the developing device can avoid image quality deterioration even when a developing process continues over a long period of time.

Abstract: Embodiments relate to a developing device for use in an image-forming apparatus including a developing roller having a conductive base surface which may be covered with a resin layer containing an ion conductive material and a silicone-modified urethane resin having an ether structure. The resin layer may be a product of a crosslinking reaction of the silicone-modified urethane resin and the ion conductive material in the presence of a crosslinking agent and a crosslinking catalyst.

Abstract: A developing unit includes a developing roller which rotates about a rotational axis to supply toner to a photoreceptor, and a magnetic roller which forms a magnetic brush with a two-component developing agent having carrier and the toner and thereby forms a toner layer on the developing roller, the developing roller including: a cylindrical core portion which includes an electric conductor; a first resistive layer which covers a cylindrical surface of the core portion; a second resistive layer which covers the first resistive layer, and has electric-resistivity lower than that of the first resistive layer; and a current leakage control member which prevents leakage of electric current from the core portion toward the second resistive layer through an end of the developing roller along a direction of the rotational axis.

Abstract: A developing unit includes a developing roller which rotates about a rotational axis to supply toner to a photoreceptor, the developing roller including: a cylindrical core portion which includes an electric conductor; a first resistive layer which covers a cylindrical surface of the core portion; a second resistive layer which covers the first resistive layer, and has electric-resistivity lower than that of the first resistive layer; and a current leakage control member which prevents leakage of electric current from the core portion toward the second resistive layer through an end of the developing roller along a direction of the rotational axis.

Abstract: A developing device is provided for visualizing an electrostatic latent image previously formed on the surface of an image carrier as a toner image. The developing device has a developing roller placed at a position facing the image carrier, carrying a toner on the surface thereof, conveying the toner and flying the conveyed toner onto the surface of the image carrier; and a resin layer coated on the surface of the developing roller. The absolute value of the difference in charge between the toners in the upper and lower layers of the toner layer formed on the developing roller as the toner carried on the developing roller is 6 ?C/g or less.

Abstract: A developing device is disclosed which includes a fixed magnet roller 25 having a plurality of magnetic poles, a development roller 27 having a development sleeve 26 that is supported axially with the ability to rotate freely, and a magnetic sealing member 29 arranged at the end of the longitudinal direction X of the development sleeve 26. Further, the length of each of the plurality of magnetic poles not facing the magnetic sealing member 29 (in other words, the development pole SI, lead-in pole N1, and blade pole N3) of the fixed magnet roller 25 are shorter than the length of each of the plurality of magnetic poles facing the magnetic sealing member 29. Accordingly, the magnetic toner retained on the peripheral surface of the development sleeve 26 is guided to the development area side in the longitudinal direction X of the development sleeve 26.

Abstract: This invention relates to a developing device 18 for use in an image-forming apparatus comprising a developing roller 100 having a conductive base surface 19 which may be covered with a resin layer 17 layer comprising an ion conductive material and a silicone-modified urethane resin having an ether structure.

Abstract: A developing device is provided with a developing roller arranged to face a photoconductor for forming an electrostatic latent image and adapted to supply a toner to the photoconductor, an agitating member for agitating a developer, a supply roller that holds the developer agitated by the agitating member, and supplies the toner to an area facing the developing roller; a restricting member for blocking the developer supplied onto the supply roller and restricting the amount of the developer conveyed by the supply roller, and an intermediate roller including a first magnetic pole facing in a direction toward the staying developer by being restricted by the restricting member for attracting the staying developer and arranged at such a position as to face the developer blocked by the restricting member. Thus, the developing device can avoid image quality deterioration even when a developing process continues over a long period of time.

Abstract: A developing unit includes a developing roller which rotates about a rotational axis to supply toner to a photoreceptor, the developing roller including: a cylindrical core portion which includes an electric conductor; a first resistive layer which covers a cylindrical surface of the core portion; a second resistive layer which covers the first resistive layer, and has electric-resistivity lower than that of the first resistive layer; and a current leakage control member which prevents leakage of electric current from the core portion toward the second resistive layer through an end of the developing roller along a direction of the rotational axis.

Abstract: A developing device includes a container for containing toner, a rotatable shaft provided in the container, a spiral shaped blade formed on an outer circumference of the shaft, and a first spiral member for conveying the toner in the longitudinal direction of the shaft by means of rotation. In addition, a toner removing member is provided for removing the toner attached to the first spiral member. Then, by rotation of the first spiral member, the toner removing member is moved in the longitudinal direction of the shaft and the direction that is orthogonal to the longitudinal direction of the shaft so as to be in contact with the surface of the first spiral member. Accordingly, it is possible to adequately scrape the toner off the spiral shaped blade and the shaft, thereby effectively prevent an aggregation of toner from occurring.

Abstract: A developing device visualizing an electrostatic latent image previously formed on the surface of an image carrier as toner image, comprising: a developing roller placed at a position facing the image carrier, carrying a toner on the surface thereof, conveying the toner and flying the conveyed toner onto the surface of the image carrier; and a resin layer coated on the surface of the developing roller, wherein the absolute value of the difference in charge between the toners in the upper and lower layers of the toner layer formed on the developing roller as the toner carried on the developing roller is 6 ?C/g or less.

Abstract: A developing device is disclosed which includes a fixed magnet roller 25 having a plurality of magnetic poles, a development roller 27 having a development sleeve 26 that is supported axially with the ability to rotate freely, and a magnetic sealing member 29 arranged at the end of the longitudinal direction X of the development sleeve 26. Further, the length of each of the plurality of magnetic poles not facing the magnetic sealing member 29 (in other words, the development pole S1, lead-in pole N1, and blade pole N3) of the fixed magnet roller 25 are shorter than the length of each of the plurality of magnetic poles facing the magnetic sealing member 29. Accordingly, the magnetic toner retained on the peripheral surface of the development sleeve 26 is guided to the development area side in the longitudinal direction X of the development sleeve 26.

Abstract: A developing device is disclosed which includes a fixed magnet roller 25 having a plurality of magnetic poles, a development roller 27 having a development sleeve 26 that is supported axially with the ability to rotate freely, and a magnetic sealing member 29 arranged at the end of the longitudinal direction X of the development sleeve 26. Further, the length of each of the plurality of magnetic poles not facing the magnetic sealing member 29 (in other words, the development pole SI, lead-in pole NI, and blade pole N3) of the fixed magnet roller 25 are shorter than the length of each of the plurality of magnetic poles facing the magnetic sealing member 29. Accordingly, the magnetic toner retained on the peripheral surface of the development sleeve 26 is guided to the development area side in the longitudinal direction X of the development sleeve 26.

Abstract: A developing device (100) according to the present invention is provided with a housing (102) for holding toner, conveying screws (104, 105) arranged in the housing (2) and each including a rotary shaft (107) and a blade (106) arranged on the rotary shaft (107) for conveying the toner from one end of the rotary shaft (107) toward the other end thereof by the rotation of the rotary shaft (107), and a developing roller (103) provided in the housing with a part of the developing roller (103) being exposed from the housing, and rotatable to obtain the toner conveyed by the conveying screws (104, 105). The conveying screws (104, 105) are constructed, for the efficient agitation of the toner, such that toner pressing forces of the blades (106) differ depending the angle of rotation of the rotary shaft (107).

Abstract: A developing device (100) according to the present invention is provided with a housing (102) for holding toner, conveying screws (104, 105) arranged in the housing (2) and each including a rotary shaft (107) and a blade (106) arranged on the rotary shaft (107) for conveying the toner from one end of the rotary shaft (107) toward the other end thereof by the rotation of the rotary shaft (107), and a developing roller (103) provided in the housing with a part of the developing roller (103) being exposed from the housing, and rotatable to obtain the toner conveyed by the conveying screws (104, 105). The conveying screws (104, 105) are constructed, for the efficient agitation of the toner, such that toner pressing forces of the blades (106) differ depending the angle of rotation of the rotary shaft (107).

Abstract: A developing device includes a container for containing toner, a rotatable shaft provided in the container, a spiral shaped blade formed on an outer circumference of the shaft, and a first spiral member for conveying the toner in the longitudinal direction of the shaft by means of rotation. In addition, a toner removing member is provided for removing the toner attached to the first spiral member. Then, by rotation of the first spiral member, the toner removing member is moved in the longitudinal direction of the shaft and the direction that is orthogonal to the longitudinal direction of the shaft so as to be in contact with the surface of the first spiral member. Accordingly, it is possible to adequately scrape the toner off the spiral shaped blade and the shaft, thereby effectively prevent an aggregation of toner from occurring.

Abstract: A developing device is disclosed which includes a fixed magnet roller 25 having a plurality of magnetic poles, a development roller 27 having a development sleeve 26 that is supported axially with the ability to rotate freely, and a magnetic sealing member 29 arranged at the end of the longitudinal direction X of the development sleeve 26. Further, the length of each of the plurality of magnetic poles not facing the magnetic sealing member 29 (in other words, the development pole S1, lead-in pole N1, and blade pole N3) of the fixed magnet roller 25 are shorter than the length of each of the plurality of magnetic poles facing the magnetic sealing member 29. Accordingly, the magnetic toner retained on the peripheral surface of the development sleeve 26 is guided to the development area side in the longitudinal direction X of the development sleeve 26.