Abstract: A transfer device transfers a visual image from an image carrier to a recording medium. The transfer device includes a first transfer element that moves and receives the visual image from the image carrier on a first surface of the first transfer element, a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a secondary transfer nip part, a facing roller provided on a second surface of the first transfer element opposite to the first surface thereof, and a constant-current power supply that applies an electric current voltage to a core metal of the facing roller to transfer the visual image from the first transfer element to the recording medium. The electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control.

Abstract: A transfer-separation device includes an intermediate transfer unit, a secondary transfer roller, a repulsive roller, a transfer unit, and a charge-eliminating/separating member. The secondary transfer roller and the repulsive roller form a nip through which the intermediate transfer unit and a recording medium pass. The transfer unit applies a bias voltage of a polarity identical to that of a toner image to the repulsive roller to secondarily transfer the toner image onto the recording medium. The charge-eliminating/separating member separates the recording medium from the intermediate transfer unit by removing charge therefrom. The volume resistance of the repulsive roller is greater than that of the secondary transfer roller. The surface resistance of the secondary transfer roller is equal to or greater than 106.5 ohm.

Abstract: A method for evaluating an electric resistance member of an image forming apparatus which can maintain good image quality, without the occurrence of transfer defects such as insufficient transfer, even in a long-term use. An intermediate transfer belt of the image forming apparatus, which is evaluated based on a fluctuation characteristic of the resistivity in a period of continuous voltage application, is used. The absolute value ??s of the amount of changes in the surface resistivity of the intermediate transfer belt within 2 seconds to 100 seconds from the beginning of voltage application is 0.3 [Log(?/)] or less, when the surface resistivity ?s is measured by applying a voltage of 500 V. The absolute value ??v of the amount of changes in the volume resistivity within 2 seconds to 100 seconds from the beginning of voltage application is 0.5 [Log(?·cm)] or less, when the volume resistivity ?v is measured by applying a voltage of 200 V.

Abstract: An image forming apparatus includes a reference-pattern detecting transfer-body, a reference-pattern detecting unit, and a condition changing unit. The reference-pattern detecting transfer-body directly transfers a reference pattern image formed on an intermediate transfer body without a recording material. The reference-pattern detecting unit detects an optical reference pattern with respect to the image transferred onto the reference-pattern detecting transfer-body. The condition changing unit changes the image forming conditions based on a result of detection.

Abstract: An image forming apparatus includes a reference-pattern detecting transfer-body, a reference-pattern detecting unit, and a condition changing unit. The reference-pattern detecting transfer-body directly transfers a reference pattern image formed on an intermediate transfer body without a recording material. The reference-pattern detecting unit detects an optical reference pattern with respect to the image transferred onto the reference-pattern detecting transfer-body. The condition changing unit changes the image forming conditions based on a result of detection.

Abstract: A transfer device transfers a visual image from an image carrier to a recording medium. The transfer device includes a first transfer element that moves and receives the visual image from the image carrier on a first surface of the first transfer element, a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a secondary transfer nip part, a facing roller provided on a second surface of the first transfer element opposite to the first surface thereof, and a constant-current power supply that applies an electric current voltage to a core metal of the facing roller to transfer the visual image from the first transfer element to the recording medium. The electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control.

Abstract: An intermediate image transfer type of image forming apparatus of the present invention includes an image carrier, an intermediate image transfer body, primary image transferring means for transferring a toner image from the image carrier to the intermediate image transfer body, and secondary image transferring means for transferring the toner image from the intermediate image transfer body to a sheet. When the surface resistivity of the intermediate image transfer body is measured by a method that repeatedly applies a voltage of 200 V for 60 seconds to the intermediate image transfer body and grounds the intermediate image transfer body for 10 seconds 1,000 consecutive times, a difference in absolute value between the logarithm of the first time of measurement and that of the thousandth time of measurement is 0.5 log ?/? or below.

Abstract: An image forming apparatus includes a reference-pattern detecting transfer-body, a reference-pattern detecting unit, and a condition changing unit. The reference-pattern detecting transfer-body directly transfers a reference pattern image formed on an intermediate transfer body without a recording material. The reference-pattern detecting unit detects an optical reference pattern with respect to the image transferred onto the reference-pattern detecting transfer-body. The condition changing unit changes the image forming conditions based on a result of detection.

Abstract: An image forming apparatus of the present invention includes an intermediate image transfer belt passed over a plurality of support members and movable while carrying a toner image of preselected polarity transferred thereto. An electrode member contacts the inside surface of the belt and is applied with a preselected voltage for transferring the toner image from the belt to a recording medium. A contact member with high electric resistance contacts the belt at a position adjacent the electrode member and includes an insulating layer thereon.

Abstract: A method for evaluating an electric resistance member of an image forming apparatus which can maintain good image quality, without the occurrence of transfer defects such as insufficient transfer, even in a long-term use. An intermediate transfer belt of the image forming apparatus, which is evaluated based on a fluctuation characteristic of the resistivity in a period of continuous voltage application, is used. The absolute value ??s of the amount of changes in the surface resistivity of the intermediate transfer belt within 2 seconds to 100 seconds from the beginning of voltage application is 0.3 [Log(?/)] or less, when the surface resistivity ?s is measured by applying a voltage of 500 V. The absolute value ??v of the amount of changes in the volume resistivity within 2 seconds to 100 seconds from the beginning of voltage application is 0.5 [Log(?·cm)] or less, when the volume resistivity ?v is measured by applying a voltage of 200 V.

Abstract: In an electrophotographic image forming apparatus of the type including a plurality of image carriers arranged along an image transfer belt and an image transferring device configured to transfer toner images of different colors from the image carriers to a sheet being conveyed by an image transfer belt or by way of the image transfer belt by applying a bias to the belt, a bias applying method of the present invention can measure a current leaking between a plurality of high-tension power supply sections or to the ends thereof as AC resistances between respective terminals and therefore to accurately measure the leak currents of DC components. Therefore, when relatively high DC components are selected, a difference in current between a plurality of power supply sections can be maintained constant.

Abstract: An image forming apparatus of the present invention includes a cleaning device for cleaning an intermediate image transfer body. A cleaning blade included in the image transfer body is formed of fluorocarbon resin or a thin layer of fluorocarbon resin is formed on the surface of the intermediate image transfer body. Further, wax is coated on the intermediate image transfer body or wax or lubricant powder is contained in toner. A moving mechanism holds the cleaning blade spaced from the intermediate image transfer body at least when image formation is not under way.

Abstract: An intermediate image transfer type of image forming apparatus of the present invention includes an image carrier, an intermediate image transfer body, primary image transferring means for transferring a toner image from the image carrier to the intermediate image transfer body, and secondary image transferring means for transferring the toner image from the intermediate image transfer body to a sheet. When the surface resistivity of the intermediate image transfer body is measured by a method that repeatedly applies a voltage of 200 V for 60 seconds to the intermediate image transfer body and grounds the intermediate image transfer body for 10 seconds 1,000 consecutive times, a difference in absolute value between the logarithm of the first time of measurement and that of the thousandth time of measurement is 0.5 log &OHgr;/□ or below.

Abstract: In an electrophotographic image forming apparatus of the type including a plurality of image carriers arranged along an image transfer belt and an image transferring device configured to transfer toner images of different colors from the image carriers to a sheet being conveyed by an image transfer belt or by way of the image transfer belt by applying a bias to the belt, a bias applying method of the present invention can measure a current leaking between a plurality of high-tension power supply sections or to the ends thereof as AC resistances between respective terminals and therefore to accurately measure the leak currents of DC components. Therefore, when relatively high DC components are selected, a difference in current between a plurality of power supply sections can be maintained constant.

Abstract: An image forming apparatus comprises a latent image support which supports an electrostatic latent image. A charging unit charges a surface of the image support. A latent image formation unit forms an electrostatic latent image on the image support surface. A developing unit develops the latent image with toner to form a toner image. A transfer unit transfers the toner image from the image support to a recording medium. A transport unit transports the recording medium so that the image support surface is countered to a surface of the recording medium. The surface of the image support has a coefficient of friction ranging from 0.1 to 0.7 according to Euler belt method, and a difference between a speed of the image support and a speed of the recording medium is below 1%, and the image support has an outermost surface containing a filler and a binder resin.

Abstract: An image forming apparatus including a belt guide member fixedly provided at an upstream side of a nip formed between a roller and a transfer roller so the belt guide member protrudes an image bearing belt such that the belt is substantially parallel with a conveying direction of a transfer medium.

Abstract: An image forming apparatus of the present invention includes an intermediate image transfer belt passed over a plurality of support members and movable while carrying a toner image of preselected polarity transferred thereto. An electrode member contacts the inside surface of the belt and is applied with a preselected voltage for transferring the toner image from the belt to a recording medium. A contact member with high electric resistance contacts the belt at a position adjacent the electrode member.

Abstract: In an electrophotographic image forming apparatus of the type including a plurality of image carriers arranged along an image transfer belt and an image transferring device configured to transfer toner images of different colors from the image carriers to a sheet being conveyed by an image transfer belt or by way of the image transfer belt by applying a bias to the belt, a bias applying method of the present invention can measure a current leaking between a plurality of high-tension power supply sections or to the ends thereof as AC resistances between respective terminals and therefore to accurately measure the leak currents of DC components. Therefore, when relatively high DC components are selected, a difference in current between a plurality of power supply sections can be maintained constant.

Abstract: A transfer device transfers a visual image from an image carrier to a recording medium. The transfer device includes a first transfer element that moves and receives the visual image from the image carrier on a first surface of the first transfer element, a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a secondary transfer nip part, a facing roller provided on a second surface of the first transfer element opposite to the first surface thereof, and a constant-current power supply that applies an electric current voltage to a core metal of the facing roller to transfer the visual image from the first transfer element to the recording medium. The electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control.

Abstract: An image forming apparatus comprises a latent image support which supports an electrostatic latent image. A charging unit charges a surface of the image support. A latent image formation unit forms an electrostatic latent image on the image support surface. A developing unit develops the latent image with toner to form a toner image. A transfer unit transfers the toner image from the image support to a recording medium. A ransnsport unit transports the recording medium so that the image support surface is countered to a surface of the recording medium. The surface of the image support has a coefficient of friction ranging from 0.1 to 0.7 according to Euler belt method, and a difference between a speed of the image support and a speed of the recording medium is below 1%, and the image support has an outermost surface containing a filler and a binder resin.