Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner. The image forming apparatus further includes a charge control mechanism for controlling the amount of charges on the photosensitive drum.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes an upstream member or layer on the electrode member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. A nip time changing controller changes the amount of time that a transfer sheet is in the nip between the transfer drum and the grounded conductive electrode member.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The transfer drum includes the inner side conductive layer, a semi-conductive layer, and a dielectric layer provided on the surface of the drum. The dielectric layer can be made to adhere to the semi-conductive layer by thermally contracting this layer or the semi-conductive and dielectric layer can be made of a one-piece construction.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner.

Abstract: An image forming apparatus of the present invention includes a photoreceptor drum on which a toner image is formed, a transfer drum for transferring the toner image formed to transfer paper by bringing the transfer paper into contact with the photoreceptor drum, and a pair of register rollers for supplying the transfer paper to the transfer drum at a predetermined time and for curling the transfer paper in an arc. The register rollers include first and second rollers pressed against each other, the first roller being a predetermined hardness and the second roller being a hardness larger than the first roller. The transfer drum is disposed on the same side as the second roller with respect to an imaginary tangent line touching the surface of the second roller at one end of a contact section between the first and second rollers.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. A variable voltage is applied to a conductive layer provided on an inner side of the transfer drum so as to either transfer the image onto the transfer paper or attract the transfer paper to the transfer roller. The transfer voltage is lower than the attracting voltage. The voltage applied to the transfer drum for both transfer and attraction will be variable depending on a detected humidity or type of transfer paper. In addition, a manual adjusting device is capable of adjusting the transfer or attraction voltage.

Abstract: An image forming apparatus of the present invention includes a photoreceptor drum on which a toner image is formed, a transfer drum for transferring the toner image to paper by bringing the paper into contact with the photoreceptor drum, the transfer drum having a dielectric layer, a semi-conductive layer and a conductive layer laminated in this order from the paper side, a power source which is connected to the conductive layer so as to apply a predetermined voltage to the conductive layer, and a conductive roller for pressing the paper against a surface of the dielectric layer so as to produce a potential difference between the conductive layer and the paper. The potential difference induces charges of the same polarity as the voltage applied to the conductive layer on the surface of the dielectric layer, and charges of the opposite polarity on a back surface of the paper pressed against the surface of the dielectric layer.

Abstract: An image forming apparatus provides a photosensitive body, a main charger, an exposing unit, developing unit and a contact-transfer charger. The main charger charges the photosensitive body with a predetermined electric potential. The exposing unit applies a laser beam on the surface of the photosensitive body to form an electric latent image. The developing unit develops the electrostatic latent image to form a toner image. The contact-transfer charger transfers the toner image on an image transfer paper. The image forming apparatus further provides controller for power supplies. The controller controls the power supplies after an image forming operation in a manner to enhance the electric potential of the photosensitive body to a high level by the main charger, drop the surface potential of the photosensitive body to a low level by the contact-transfer charger and then to cut off a bias voltage of the developing unit.

Abstract: An image forming apparatus provides a photosensitive body, a main charger, an exposing unit, developing unit and a contact-transfer charger. The main charger charges the photosensitive body with a predetermined electric potential. The exposing unit applies a laser beam on the surface of the photosensitive body to form an electric latent image. The developing unit develops the electrostatic latent image to form a toner image. The contact-transfer charger transfers the toner image on an image transfer paper. The image forming apparatus further provides controller for power supplies. The controller controls the power supplies after an image forming operation in a manner to enhance the electric potential of the photosensitive body to a high level by the main charger, drop the surface potential of the photosensitive body to a low level by the contact-transfer charger and then to cut off a bias voltage of the developing unit.

Abstract: A method for the heat treatment of metal strips which comprises heating and cooling a metal strip while allowing the strip to pass through a heat treatment apparatus in a floating manner. When passing through the apparatus in such a manner, the strip is curved in the wave forms in the direction of feed thereof. Such curvatures given to the strip increase the resistance of the strip against buckling stress. The increased resistance of the strip against buckling stress is stronger than the thermal stress produced therein during the heating and cooling treatment so that the strip can be heated and cooled without any wrinkles produced therein.

Abstract: During the process in which an aluminum strip is moved in a floating mode, the strip is first heated, then cooled and annealed. When the aluminum strip is cooled, the strip is moved while being curved into a wave-like form toward the moving direction thereof. The aluminum strip is curved in a manner as described, and as a result, the aluminum strip increases in antibuckling stress. The increased antibuckling stress overcomes a thermal stress produced in the direction of the width of the aluminum strip during the process of cooling. Accordingly, the aluminum strip is cooled without formation of wrinkle parallel to the longitudinal direction of the strip.

Abstract: During the process of movement of an aluminum strip in a floating mode, the strip is first heated and then cooled for the annealing. In cooling the aluminum strip, the aluminum strip is first cooled to a predetermined temperature at an easy cooling temperature gradient, and subsequently cooled to a room temperature at a sharper cooling temperature gradient than the former. During the process of the cooling, a significant thermal stress is not produced in the aluminum strip, and the aluminum strip is cooled without being wrinkled.