Abstract: A developing unit includes a toner storage portion containing toner and a toner supply member, and a development portion disposed above the toner storage portion. A partition wall divides the toner storage portion from the development portion. The partition wall includes a supply opening that defines a toner supply path from the toner storage portion to the development portion, and a discharge opening that defines a toner discharge path from the development portion to the toner storage portion.

Abstract: A developing device configured such that developer is uniformly distributed in the developing device, thereby preventing deterioration of image quality due to poor supply of the developer and preventing damage to an agitating device due to the developer non-uniformly distributed in the developing device, and an image forming apparatus including the same are provided.

Abstract: An image forming apparatus includes a main body of the image forming apparatus; a developing cartridge that is detachably disposed in the main body and includes an image carrier; a charging roller that is disposed to face the image carrier in the developing cartridge and charges a surface of the image carrier; a charging roller separating unit that moves the charging roller between a first position in which the charging roller is in contact with the image carrier and a second position in which the charging roller is spaced apart from the image carrier; and a paper feeding cassette detachably disposed in the main body; wherein when the paper feeding cassette is first mounted, the charging roller is fixed in the second position by the charging roller separating unit.

Abstract: An image forming apparatus includes a main body of the image forming apparatus; a developing cartridge that is detachably disposed in the main body and includes an image carrier; a charging roller that is disposed to face the image carrier in the developing cartridge and charges a surface of the image carrier; a charging roller separating unit that moves the charging roller between a first position in which the charging roller is in contact with the image carrier and a second position in which the charging roller is spaced apart from the image carrier; and a paper feeding cassette detachably disposed in the main body; wherein when the paper feeding cassette is first mounted, the charging roller is fixed in the second position by the charging roller separating unit.

Abstract: A developing unit includes a toner storage portion containing toner and a toner supply member, and a development portion disposed above the toner storage portion. A partition wall divides the toner storage portion from the development portion. The partition wall includes a supply opening that defines a toner supply path from the toner storage portion to the development portion, and a discharge opening that defines a toner discharge path from the development portion to the toner storage portion.

Abstract: An image forming apparatus includes a photosensitive body, a light scanning lamp, and a lamp controller. The image forming apparatus has a surface capable of accepting an electric potential. The light scanning lamp can scan a lamp light toward the photosensitive body to change the electric potential of the photosensitive body. The lamp controller moves between a blocking position to block the lamp light from reaching the surface of the photosensitive body, and an unblocking position that is spaced from the blocking position and allows the lamp light to reach the surface of the photosensitive body.

Abstract: An electro photographic image forming apparatus includes first and second photosensitive bodies, first and second exposing units to form electrostatic latent images on the first and second photosensitive bodies each of which being charged to a uniform electric potential, a first developing unit to develop the electrostatic latent image on the first photosensitive body by supplying a transparent toner thereto, and a second developing unit to develop the electrostatic latent image on the second photosensitive body by supplying color toners thereto, wherein the first developing unit is a developing unit employing a two-component developing technique using a magnetic carrier and a transparent toner.

Abstract: An image forming apparatus including a photosensitive member on which an electrostatic latent image is formed, an image forming unit to form a visible image on the photosensitive member formed with the electrostatic latent image, and a transfer device to transfer the visible image formed on the photosensitive member onto a printing medium. The image forming unit includes a developing agent storage vessel to store a developing agent therein, a developing unit having a conductive layer to which the developing agent is attached and used to attach the developing agent to the photosensitive member, and a supply unit to supply the developing agent stored in the developing agent storage vessel to the developing unit. The developing unit and the supply unit satisfy a relational expression 1.7?log Sr/log Dr?2.5, where Sr a volume resistance of the supply unit and Dr is a volume resistance of the developing unit.

Abstract: Provided are a multi-pass image forming apparatus and an image forming method using the same. The multi-pass image forming apparatus includes a plurality of developers for forming a plurality of electrostatic latent images using toners having different polarities and colors in one development process and for forming a multi-color image in at least two development processes; an exposure unit for forming the plurality of the electrostatic latent images on a photosensitive medium; and an intermediate transferring unit for having a toner images transferred thereon from the photosensitive medium that overlap to form the multi-color image, wherein the toner image may overlap another toner image on the intermediate transferring unit.

Abstract: Provided is an electrophotographic developing agent including: toner particles including a binder resin, a colorant, and a charge control agent; and an external additive added to the surface of the toner particles, wherein the external additive includes at least one inorganic particulate component and at least two types of strontium titanate particulate component having different mean primary particle diameters. Typically, the inorganic particulate component is not strontium titanate. Also, an electrophotographic image forming apparatus using the electrophotographic developing agent is provided. The strontium titanate particulate component having different mean primary particle diameters are used as an external additive to maintain uniform charging characteristics and to prevent fog in a non-image area, thereby obtaining good image quality.

Abstract: An image forming apparatus including a photosensitive member on which an electrostatic latent image is formed, an image forming unit to form a visible image on the photosensitive member formed with the electrostatic latent image, and a transfer device to transfer the visible image formed on the photosensitive member onto a printing medium. The image forming unit includes a developing agent storage vessel to store a developing agent therein, a developing unit having a conductive layer to which the developing agent is attached and used to attach the developing agent to the photosensitive member, and a supply unit to supply the developing agent stored in the developing agent storage vessel to the developing unit. The developing unit and the supply unit satisfy a relational expression 1.7?logSr/logDr?2.5, where Sr a volume resistance of the supply unit and Dr is a volume resistance of the developing unit.

Abstract: An image forming apparatus includes a photosensitive body having surface capable of accepting an electric potential, a light scanning lamp which scans a lamp light toward the photosensitive body to change the electric potential of the photosensitive body, and a lamp controller which moves between a blocking position to block the lamp light from reaching the surface of the photosensitive body, and an unblocking position which is spaced from the blocking position and allows the lamp light to reach the surface of the photosensitive body.

Abstract: An electrophotographic image forming apparatus includes first and second photosensitive bodies, first and second exposing units to form electrostatic latent images on the first and second photosensitive bodies each of which being charged to a uniform electric potential, a first developing unit to develop the electrostatic latent image on the first photosensitive body by supplying a transparent toner thereto, and a second developing unit to develop the electrostatic latent image on the second photosensitive body by supplying color toners thereto, wherein the first developing unit is a developing unit employing a two-component developing technique using a magnetic carrier and a transparent toner.

Abstract: A hybrid type image forming apparatus is provided. The apparatus uses a developer that contains a mixture of a toner and a carrier, and includes a photosensitive body and a development unit. An electrostatic latent image is formed on the photosensitive body. The development unit includes a magnetic roller and a developing roller. The magnetic roller forms a magnetic brush containing the toner and the carrier on the outer periphery of the magnetic roller, and the developing roller is installed such that the developing roller does not contact the magnetic roller and the photosensitive body to develop the electrostatic latent image using the toner supplied from the magnetic brush. A resistivity of the developer is no greater than 109 ?cm.

Abstract: Provided are a multi-pass image forming apparatus and an image forming method using the same. The multi-pass image forming apparatus includes a plurality of developers for forming a plurality of electrostatic latent images using toners having different polarities and colors in one development process and for forming a multi-color image in at least two development processes; an exposure unit for forming the plurality of the electrostatic latent images on a photosensitive medium; and an intermediate transferring unit for having a toner images transferred thereon from the photosensitive medium that overlap to form the multi-color image, wherein the toner image may overlap another toner image on the intermediate transferring unit.

Abstract: Provided is an electrophotographic developing agent including: toner particles including a binder resin, a colorant, and a charge control agent; and an external additive added to the surface of the toner particles, wherein the external additive includes at least one inorganic particulate component and at least two types of strontium titanate particulate component having different mean primary particle diameters. Typically, the inorganic particulate component is not strontium titanate. Also, an electrophotographic image forming apparatus using the electrophotographic developing agent is provided. The strontium titanate particulate component having different mean primary particle diameters are used as an external additive to maintain uniform charging characteristics and to prevent fog in a non-image area, thereby obtaining good image quality.

Abstract: A developer-supplying system of an image forming apparatus includes a developer-supplying roller supplying a developer onto a developing roller and removing residual developer which is not transferred onto a photosensitive body, but remains on the developing roller after developing, and a residual developer-withdrawing member disposed in a spaced-apart relation with and opposite to the developer-supplying roller to withdraw the residual developer removed from the developing roller by the developer-supplying roller and transferred onto the developer-supplying roller. The developer-supplying system can not only prevent developer-supplying efficiency and residual developer-withdrawal efficiency of the developer-supplying roller from being reduced, but also reduce stress to the developer to prevent the developer from deteriorating.

Abstract: A non-magnetic one-component toner is produced to provide a uniform image density. The non-magnetic one-component toner includes coloration particles that include a binder resin, a pigment, and a charge control agent; and a surface additive including 0.1-4 wt % of one or more selected from the group consisting of silica, titanium oxide, silicon carbide, and alumina, and a resin bead where the surface additive has an average volumetric particle size of 0.01-15 ?m where the percentages are based on the total weight of the toner. The non-magnetic one-component toner provides a uniform image density for a long duration and prevents the formation of poor images such as fogging, without performing a separate process such as increasing of the pressure of a cleaning blade or improving the surface smoothness of a latent image drum.

Abstract: An image forming apparatus having a uniform nip between a photosensitive body and a transfer body. The image forming apparatus has a photosensitive unit on which an electrostatic latent image is formed, a developer feed unit to feed a developer onto the electrostatic latent image to form a visible image, and a transfer unit. The transfer unit has a curved side of a semi-hollow tubular shape that contacts the photosensitive unit, and a planar side opposite the curved side and secured at a support member, to transfer the visible image formed on the photosensitive unit to a recording medium. The curved side of the transfer unit has a uniform radius of curvature in an axial direction. Accordingly, the image forming apparatus can not only maintain a constant nip in relation to electrical resistance and contact pressure, but can also adjust the electrical resistance of the transfer unit by appropriately setting factors such as volume resistivity of the conductive elastic member.

Abstract: A developer-supplying system of an image forming apparatus includes a developer-supplying roller supplying a developer onto a developing roller and removing residual developer which is not transferred onto a photosensitive body, but remains on the developing roller after developing, and a residual developer-withdrawing member disposed in a spaced-apart relation with and opposite to the developer-supplying roller to withdraw the residual developer removed from the developing roller by the developer-supplying roller and transferred onto the developer-supplying roller. The developer-supplying system can not only prevent developer-supplying efficiency and residual developer-withdrawal efficiency of the developer-supplying roller from being reduced, but also reduce stress to the developer to prevent the developer from deteriorating.