Abstract: An image forming apparatus includes: a latent image carrier; a first charging unit which charges the latent image carrier; a second charging unit which supplies a charge having a reverse polarity of the charged polarity of the toner; a toner carrying roller which carries a toner layer containing both a contact toner which comes in direct contact with the surface of the toner carrying roller and a non-contact toner which comes in contact with the contact toner and does not come in contact with the surface of the toner carrying roller; an electric field forming unit which develops the electrostatic latent image by the toner by generating an alternate electric field as a toner fly electric field between the latent image carrier and the toner carrying roller; and a transfer unit which transfers a toner image formed by developing the electrostatic latent image to a transfer medium.

Abstract: An image forming apparatus includes: a latent image carrier; a first charging unit which charges the latent image carrier; a second charging unit which supplies a charge having a reverse polarity of the charged polarity of the toner; a toner carrying roller which carries a toner layer containing both a contact toner which comes in direct contact with the surface of the toner carrying roller and a non-contact toner which comes in contact with the contact toner and does not come in contact with the surface of the toner carrying roller; an electric field forming unit which develops the electrostatic latent image by the toner by generating an alternate electric field as a toner fly electric field between the latent image carrier and the toner carrying roller; and a transfer unit which transfers a toner image formed by developing the electrostatic latent image to a transfer medium.

Abstract: An image forming apparatus is operable to form an image on a recording medium. An image carrier is adapted such that a toner image is formed thereon by developing an electrostatic latent image. An intermediate transfer member is adapted such that the toner image is primarily transferred thereto. In a transfer device, a roller member is adapted to come in contact with the intermediate transfer member. A first bias voltage applier is operable to provide a transfer voltage, thereby applying a first bias voltage between the roller member and the intermediate transfer member to secondarily transfer the toner image onto the recording medium in order to obtain the image. A charge eliminator is disposed in the vicinity of the roller member. A second bias voltage applier is operable to apply a second bias voltage to the charge eliminator to eliminate charges on the recording medium which has been subjected to the application of the first bias voltage.

Abstract: An image forming apparatus includes: an image supporting member; a charging member charging the image supporting member; an image forming member forming a latent image on the image supporting member; a developer supporting member developing the latent image on the image supporting member; a transfer member to which the developed image is transferred; a charging bias controller applying a charging bias immediately before a position at which the image is formed on the image supporting member in a printing operation passes the charging member; and a transfer bias controller applying a transfer bias immediately before the position at which the image is formed on the image supporting member in the printing operation reaches a nip portion between the image supporting member and the transfer member.

Abstract: A development unit includes: an image carrier; a charger that charges the image carrier; an image writing means for forming a latent image on the image carrier; a developer carrier that develops the latent image on the image carrier; and an image write control means for allowing the image writing means to preliminarily expose the image carrier before the position on the image carrier at which an image is to be formed at the time of printing operation is passed through the image writing means.

Abstract: An image forming apparatus is operable to form an image on a recording medium. An image carrier is adapted such that a toner image is formed thereon by developing an electrostatic latent image. An intermediate transfer member is adapted such that the toner image is primarily transferred thereto. In a transfer device, a roller member is adapted to come in contact with the intermediate transfer member. A first bias voltage applier is operable to provide a transfer voltage, thereby applying a first bias voltage between the roller member and the intermediate transfer member to secondarily transfer the toner image onto the recording medium in order to obtain the image. A charge eliminator is disposed in the vicinity of the roller member. A second bias voltage applier is operable to apply a second bias voltage to the charge eliminator to eliminate charges on the recording medium which has been subjected to the application of the first bias voltage.

Abstract: The invention provides an image-forming apparatus comprising: at least one latent image holding member on which an electrostatic latent image is to be formed; developing devices having toners of different colors for developing the electrostatic latent image on the latent image holding member to form a toner image; and an intermediate transfer medium onto which the thus formed toner image is to be transferred, wherein the intermediate transfer medium has a work function smaller than or equal to the work function of each of the toners.

Abstract: The invention provides an imaging system wherein toners of two or more colors are used to form toner images and the toner images are successively used to form a color image on a recording material. The imaging system can form an image with high transfer efficiency. An electrostatic latent image is formed on an image carrier. Using developing units for two or more colors, images are formed. Then, the images are successively transferred onto an intermediate transfer medium at a transfer voltage fed from a constant-voltage power supply. The developing units are located such that development occurs in descending toner work function order.

Abstract: An image forming apparatus including a latent image carrier and a developing means for charging a toner into a negative polarity by triboelectric charging, wherein the work function of the toner is set to be larger than the work function of the surface of the latent image carrier. When the apparatus includes an intermediate transfer medium, the work function of the toner is set to be larger than the work function of the surface of the intermediate transfer medium. In another embodiment, the work function ?OPC of the surface of the latent image carrier, the work function ?t of the toner, and the work function ?TM of the surface of the intermediate transfer medium are set to satisfy a relationship ?t>?OPC>?TM. These relationships help to reduce fog, and improve transfer efficiency which reduces the consumption of the toner.

Abstract: An image forming apparatus of the present invention comprises: a latent image carrier; and a developing means for charging a toner into a negative polarity by triboelectric charging, for converting an electrostatic latent image on said latent image carrier to a visible image with said toner and is characterized in that (1) the work function (?t) of said toner is set to be larger than the work function (?OPC) of the surface of said latent image carrier, or (2) in case that the apparatus is of a type transferring the visible image to an intermediate transfer medium, the apparatus is characterized in that the work function (?t) of said toner is set to be larger than the work function (?TM) of the surface of said intermediate transfer medium or (3) the work function (?OPC) of the surface of said latent image carrier, the work function (?t) of said toner, and the work function (?TM) of the surface of said intermediate transfer medium are set to satisfy a relation ?t>?OPC>?TM.

Abstract: The invention provides an imaging system wherein toners of two or more colors are used to form toner images and the toner images are successively used to form a color image on a recording material. The imaging system can form an image with high transfer efficiency. An electrostatic latent image is formed on an image carrier. Using developing units for two or more colors, images are formed. Then, the images are successively transferred onto an intermediate transfer medium at a transfer voltage fed from a constant-voltage power supply. The developing units are located such that development occurs in descending toner work function order.

Abstract: By causing the movement of charge from a toner to a latent image carrier, the amount of charge of the toner is lowered to an amount of charge suitable for facilitating the transfer of toner so as to improve the transfer efficiency. For this, an image forming apparatus includes a latent image carrier and a developing means for forming a negatively chargeable toner layer compose of two stories or less on a toner carrier by a toner layer thickness regulating member. An electrostatic latent image on the latent image carrier is developed with the toner to form a visible image and the visible image is transferred to a transfer medium. Further, the work functions (&PHgr;opc) of the surface of the latent image carrier is set to be larger than the work function (&PHgr;t) of the toner.

Abstract: An image forming apparatus including a latent image carrier and a developing device for charging a toner into a negative polarity by triboelectric charging, wherein the work function of the toner is set to be larger than the work function of the surface of the latent image carrier. When the apparatus includes an intermediate transfer medium, the work function of the toner is set to be larger than the work function of the surface of the intermediate transfer medium. In another embodiment, the work function &PHgr;opc of the surface of the latent image carrier, the work function &PHgr;t of the toner, and the work function &PHgr;TM of the surface of the intermediate transfer medium are set to satisfy a relationship &PHgr;t>&PHgr;OPC>&PHgr;TM. These relationships help to reduce fog, and improve transfer efficiency which reduces the consumption of the toner.

Abstract: The invention provides an image-forming apparatus comprising: at least one latent image holding member on which an electrostatic latent image is to be formed; developing devices having toners of different colors for developing the electrostatic latent image on the latent image holding member to form a toner image; and an intermediate transfer medium onto which the thus formed toner image is to be transferred, wherein the intermediate transfer medium has a work function smaller than or equal to the work function of each of the toners.

Abstract: An image forming apparatus of cleaner-less system using toner particles comprising resin mother particles coated with external additives, having an adhesive force between a primary transfer member and the toner particle that is larger than the adhesive force between an image carrier and the toner particle, and an adhesive force between the primary transfer member and the resin mother particle that is larger than the adhesive force between the image carrier and the resin mother particle. As a result, a stable transfer property is provided which prevents the generation of residual toner particles. Furthermore, when images with toner particles of different colors are superposed at the transfer portion, color-to-color separation of the toner particles can be prevented by setting the adhesive force between the resin mother particles of the different colors to be larger than the adhesive force between the image carrier and the resin mother particle.

Abstract: The object of the invention is to provide an image carrier which is capable of securely preventing the leakage of charge in lateral direction so as to stably conduct the application or removal of charge and which can be easily manufactured. An image carrier comprises a dielectric layer, wherein charge is transferred between the dielectric layer and a charge-transfer controlling means so as to apply charge to or remove charge from the dielectric layer, wherein the dielectric layer is formed in such a structure that a large number of conductive portions are formed to be separately dispersed in its outer surface. Charge is transferred between the conductive portions and the charge-transfer controlling means so as to apply charge to or remove charge from the conductive portions.

Abstract: The object of the invention is to provide an image carrier which is capable of securely preventing the leakage of charge in lateral direction so as to stably conduct the application or removal of charge and which can be easily manufactured. An image carrier comprises a dielectric layer, wherein charge is transferred between the dielectric layer and a charge-transfer controlling means so as to apply charge to or remove charge from the dielectric layer, wherein the dielectric layer is formed in such a structure that a large number of conductive portions are formed to be separately dispersed in its outer surface. Charge is transferred between the conductive portions and the charge-transfer controlling means so as to apply charge to or remove charge from the conductive portions.

Abstract: An image forming apparatus of the present invention comprises: a latent image carrier; and a developing means for charging a toner into a negative polarity by triboelectric charging, for converting an electrostatic latent image on said latent image carrier to a visible image with said toner and is characterized in that (1) the work function (&PHgr;t) of said toner is set to be larger than the work function (&PHgr;OPC) of the surface of said latent image carrier, or (2) in case that the apparatus is of a type transferring the visible image to an intermediate transfer medium, the apparatus is characterized in that the work function (&PHgr;t) of said toner is set to be larger than the work function (&PHgr;TM) of the surface of said intermediate transfer medium or (3) the work function (&PHgr;OPC) of the surface of said latent image carrier, the work function (&PHgr;t) of said toner, and the work function (&PHgr;TM) of the surface of said intermediate transfer medium are set to satisfy a relation &PHgr;t>&PHgr

Abstract: An image forming apparatus of cleaner-less system using toner particles comprising resin mother particles coated with external additives, having an adhesive force between a primary transfer member and the toner particle that is larger than the adhesive force between an image carrier and the toner particle, and an adhesive force between the primary transfer member and the resin mother particle that is larger than the adhesive force between the image carrier and the resin mother particle. As a result, a stable transfer property is provided which prevents the generation of residual toner particles. Furthermore, when images with toner particles of different colors are superposed at the transfer portion, color-to-color separation of the toner particles can be prevented by setting the adhesive force between the resin mother particles of the different colors to be larger than the adhesive force between the image carrier and the resin mother particle.

Abstract: By causing the movement of charge from a toner to a latent image carrier, the amount of charge of the toner is lowered to an amount of charge suitable for facilitating the transfer of toner so as to improve the transfer efficiency. For this, an image forming apparatus comprises a latent image carrier 1 and a developing means 4 for forming a negatively chargeable toner layer composed of two stories or less on a toner carrier 10 by a toner layer thickness regulating member 9, wherein an electrostatic latent image on the latent image carrier is developed with the toner to form a visible image and the visible image is transferred to a transfer medium 5, and is characterized in that the work function (&PHgr;opc) of the surface of the latent image carrier is set to be larger than the work function (&PHgr;t) of the toner.