Abstract: A transfer device includes a holding body that holds a toner image and to which a first tension and a second tension, which is smaller than the first tension, are applied, a transfer body that transfers the toner image to a recording medium while transporting the recording medium between the transfer body and the holding body, and a setting portion that sets tension applied to the holding body to the second tension when a mass of a toner of an uppermost toner layer constituting the toner image and disposed on the holding body is equal to or exceeds a threshold.

Abstract: An image forming apparatus includes: a transfer member that transfers a toner image to a continuous sheet, the transfer member having a lower hardness than a member opposed thereto with the continuous sheet therebetween when the continuous sheet is transported; and a moving unit that moves the transfer member in a direction intersecting the direction in which the continuous sheet is transported.

Abstract: An image forming apparatus includes multiple first image forming units, a second image forming unit, and a controller. The first image forming units transfer toner images developed with colored toners to a transfer body, and form first images on the transfer body. The second image forming unit transfers a toner image developed with a spot color toner different from colors of the colored toners to the transfer body prior to the first image forming units, and forms a second image serving as an undercoat or an overcoat of the first images on the transfer body. The controller controls the first image forming units in order that amounts of the colored toners used for forming the first images by the first image forming units become less than amounts of the colored toners used when the first images are formed prior to the second image.

Abstract: An image forming apparatus includes multiple first image forming units, a second image forming unit, and a controller. The first image forming units transfer toner images developed with colored toners to a transfer body, and form first images on the transfer body. The second image forming unit transfers a toner image developed with a spot color toner different from colors of the colored toners to the transfer body prior to the first image forming units, and forms a second image serving as an undercoat or an overcoat of the first images on the transfer body. The controller controls the first image forming units in order that amounts of the colored toners used for forming the first images by the first image forming units become less than amounts of the colored toners used when the first images are formed prior to the second image.

Abstract: An image forming apparatus includes at least one image carrier that carries a toner image, an intermediate transfer body that is rotatable and that faces the image carrier, an opposing member that is positioned upstream of a second transfer section in a rotation direction of the intermediate transfer body and that faces the intermediate transfer body, and a voltage application unit that applies an AC voltage, whose polarity reverses, and forms an AC electric field between the intermediate transfer body and the opposing member. A first transfer section in which the toner image on the image carrier is transferred onto a surface of the intermediate transfer body is formed. The second transfer section that is positioned downstream of the first transfer section in the direction of rotation of the intermediate transfer body and in which the toner image on the intermediate transfer body is transferred onto a medium is formed.

Abstract: An image forming apparatus includes an image forming unit that forms an image with toner, an image carrier, a transfer unit that transfers an image from the image carrier to a medium, and a power supply control unit that applies a transfer bias generated by superimposing an AC bias and a DC bias to the transfer unit. Multiple first images are transferred to a medium, the first images being formed by setting one of an amplitude value of the AC bias, and a DC bias value representing a value of the DC bias to a fixed value and changing the other one at a preset interval. Multiple second images are transferred to a medium, the second images being formed by setting the one of the amplitude value and the DC bias value to a fixed value different from the fixed value, and changing the other one at a preset interval.

Abstract: An image forming apparatus includes at least one image carrier that carries a toner image, an intermediate transfer body that is rotatable and that faces the image carrier, an opposing member that is positioned upstream of a second transfer section in a rotation direction of the intermediate transfer body and that faces the intermediate transfer body, and a voltage application unit that applies an AC voltage, whose polarity reverses, and forms an AC electric field between the intermediate transfer body and the opposing member. A first transfer section in which the toner image on the image carrier is transferred onto a surface of the intermediate transfer body is formed. The second transfer section that is positioned downstream of the first transfer section in the direction of rotation of the intermediate transfer body and in which the toner image on the intermediate transfer body is transferred onto a medium is formed.

Abstract: A transfer member includes a shaft and a body. When a measurement member is brought into contact with an outer surface of the body and voltage applied to the measurement member is changed by electrically connecting the shaft to ground, a time constant ?v is measured based on a change in electric potential occurring on a surface of the measurement member. When a first measurement member is brought into contact with the outer surface, a second measurement member is brought into contact with the outer surface while being spaced apart from the first member by a predetermined distance in a circumferential direction of the outer surface, and voltage applied to the first member is changed by electrically connecting the shaft to ground, a time constant ?s is measured based on a change in electric potential occurring on a surface of the second member. ?v is larger than ?s.

Abstract: A transfer member includes a shaft and a body. When a measurement member is brought into contact with an outer surface of the body and voltage applied to the measurement member is changed by electrically connecting the shaft to ground, a time constant ?v is measured based on a change in electric potential occurring on a surface of the measurement member. When a first measurement member is brought into contact with the outer surface, a second measurement member is brought into contact with the outer surface while being spaced apart from the first member by a predetermined distance in a circumferential direction of the outer surface, and voltage applied to the first member is changed by electrically connecting the shaft to ground, a time constant ?s is measured based on a change in electric potential occurring on a surface of the second member. ?v is larger than ?s.

Abstract: An image forming apparatus includes an image bearing member that bears a toner image; a transfer member that faces the image bearing member, nips a recording medium together with the image bearing member, and allows the recording medium to pass therebetween; a transfer-bias applying unit that applies transfer bias voltage to generate an electric field between the transfer member and the image bearing member; a cleaning member that is disposed in contact with the transfer member and removes toner from the transfer member; a cleaning-bias applying unit that applies cleaning bias voltage between the cleaning member and the transfer member; a transfer-toner-amount estimating unit that estimates an amount of toner to be transferred from the image bearing member to the transfer member when the recording medium does not pass therebetween; and a cleaning-bias controller that controls the cleaning bias voltage in correspondence with the estimated amount of toner.

Abstract: An image forming apparatus includes an image carrying member that carries a toner image; a transfer member whose endless peripheral surface that circulates is disposed so as to oppose the image carrying member; a cleaning member that is disposed so as to contact the peripheral surface of the transfer member and removes toner adhered to a surface of the transfer member; a cleaning bias applying unit that applies a cleaning bias voltage to a portion between the cleaning member and the transfer member; a print mode switching section that switches a print mode between print modes including a borderless print mode and an ordinary print mode; and a bias voltage controller that performs control so that the cleaning bias voltage is a first bias voltage value in the ordinary print mode and a second bias voltage value in the borderless print mode.

Abstract: An image forming apparatus includes an image bearing member that bears a toner image; a transfer member that faces the image bearing member, nips a recording medium together with the image bearing member, and allows the recording medium to pass therebetween; a transfer-bias applying unit that applies transfer bias voltage to generate an electric field between the transfer member and the image bearing member; a cleaning member that is disposed in contact with the transfer member and removes toner from the transfer member; a cleaning-bias applying unit that applies cleaning bias voltage between the cleaning member and the transfer member; a transfer-toner-amount estimating unit that estimates an amount of toner to be transferred from the image bearing member to the transfer member when the recording medium does not pass therebetween; and a cleaning-bias controller that controls the cleaning bias voltage in correspondence with the estimated amount of toner.

Abstract: A cleaning member 100 is constituted, for example, by a roll-shaped member having a shaft 100A and an elastic layer 100B. The elastic layer 100B is spirally disposed on the surface of the shaft 100A. A space 100C enclosed by the spirally disposed elastic layer 100B (side surface thereof) and the shaft 100A (outer circumferential surface thereof) is provided and a filling member 100D for filling the space 100C is disposed in a portion of the space 100C.

Abstract: The present invention provides a cleaning member for an image forming apparatus, including: an axle; and a belt-like elastic medium that is wound on the outer circumferential surface of the axle in a spiral shape and that includes a first edge portion in at least one of both ends in the width direction thereof and a second edge portion coming in contact with a surface to be cleaned at an angle different from that of the first edge portion.

Abstract: A cleaning member 100 is constituted, for example, by a roll-shaped member having a shaft 100A and an elastic layer 100B. The elastic layer 100B is spirally disposed on the surface of the shaft 100A. A space 100C enclosed by the spirally disposed elastic layer 100B (side surface thereof) and the shaft 100A (outer circumferential surface thereof) is provided and a filling member 100D for filling the space 100C is disposed in a portion of the space 100C.

Abstract: The present invention provides a cleaning member for an image forming apparatus, including: an axle; and a belt-like elastic medium that is wound on the outer circumferential surface of the axle in a spiral shape and that includes a first edge portion in at least one of both ends in the width direction thereof and a second edge portion coming in contact with a surface to be cleaned at an angle different from that of the first edge portion.

Abstract: A charge roll disposed in an image forming apparatus, for charging an image carrier for carrying an image, and to be cleaned by a cleaning member, the charge roll including: a shaft and an electrically conductive layer provided around the shaft, an axial end portion of the electrically conductive layer in an area in contact with the cleaning member being formed into skin layer portions thinner than other portions of the electrically conductive layer, is provided.

Abstract: A charge roll disposed in an image forming apparatus, for charging an image carrier for carrying an image, and to be cleaned by a cleaning member, the charge roll including: a shaft and an electrically conductive layer provided around the shaft, an axial end portion of the electrically conductive layer in an area in contact with the cleaning member being formed into skin layer portions thinner than other portions of the electrically conductive layer, is provided.

Abstract: In a two-component developing unit, by devising the layout of magnetic poles 6 (particularly a pickup magnetic pole 6b and a trimming magnetic pole 6c) of a magnet member 5 arranged inside a developer carrier 3, an excess portion of a developer G picked up onto the surface of the developer carrier 3 is allowed to drop in the vicinity of the height of the rotational center O of the developer carrier 3, and only the developer G restricted to a predetermined layer thickness is carried and transported to a development region m. A charging member 9 is disposed over a periphery of the developer carrier 3, as required. In addition, the layout of the magnetic poles 6 of the magnet member 5 arranged inside the developer carrier 3 is set variably between the time of development and the time of nondevelopment, and the amount of developer carried on the surface of the developer carrier and transported to the development region m is set to substantially zero at the time of nondevelopment.

Abstract: In a two-component developing unit, by devising the layout of magnetic poles 6 (particularly a pickup magnetic pole 6b and a trimming magnetic pole 6c) of a magnet member 5 arranged inside a developer carrier 3, an excess portion of a developer G picked up onto the surface of the developer carrier 3 is allowed to drop in the vicinity of the height of the rotational center O of the developer carrier 3, and only the developer G restricted to a predetermined layer thickness is carried and transported to a development region m. A charging member 9 is disposed over a periphery of the developer carrier 3, as required. In addition, the layout of the magnetic poles 6 of the magnet member 5 arranged inside the developer carrier 3 is set variably between the time of development and the time of nondevelopment, and the amount of developer carried on the surface of the developer carrier and transported to the development region m is set to substantially zero at the time of nondevelopment.