Abstract: An endless belt is extended over extending rollers, and carries a toner image transferred from an image carrier or a transfer sheet. The endless belt includes a front-side reinforcing member and a rear-side reinforcing member, and a guide member for preventing meandering fixed over an approximately entire circumference on the rear-side reinforcing member. The extending rollers include a step portion provided in an end area in an axial direction facing to the rear-side reinforcing member, which has a diameter smaller than a center area in the axial direction. The front-side reinforcing member has a width wider than a width of the rear-side reinforcing member.

Abstract: A multi-layer endless belt member, which can be incorporated in a transfer unit for use in an image forming apparatus, includes a base layer and a surface layer disposed on the base layer and having a higher resistivity and has a first resistivity of a first surface thereof and a second resistivity of a second surface thereof opposite the first surface different from the first resistivity. The second resistivity of the second surface ranges from approximately 9.0 to approximately 12.5 in a common logarithm value (log[?/square]) when measured after 500V is applied for 10 seconds. An amount of resistivity change in the first resistivity ranges from approximately 0.5 to approximately 1.5 after application of 100V and is 0.2 or smaller after application of 500V. An amount of resistivity change in the second resistivity is 0.1 or smaller after application of 100V and 500V.

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 multi-layer endless belt member with a high-resistance surface layer for use in an image forming apparatus. A volume resistivity thereof ranges from approximately 8.0 to approximately 11.0 in log[?·cm]. An amount of resistivity change of a first surface thereof is greater than an amount of resistivity change of a second surface thereof by 0.05 or greater in log [?/square], where the amount of resistivity change of the first surface indicates a difference between surface resistivity values measured after a given voltage is applied for 1 second and for 100 seconds on the first surface thereof and the amount of resistivity change of the second surface indicates a difference between surface resistivity values measured after a given voltage is applied for 1 second and for 100 seconds on the second surface thereof.

Abstract: A transfer device includes an endless belt, an external roller, and an internal roller. The external roller is arranged outside of the loop of the endless belt and the inner roller is arranged inside of the loop of the endless belt. The endless belt is sandwiched between the external roller and the internal roller. A surface hardness of the external roller and a surface hardness of the internal roller are 50 degrees or more in an asker C scale. A logarithm (LogR) of volume resistivity of the intermediate transfer member is 10.0 or less.

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 endless belt is extended over extending rollers, and carries a toner image transferred from an image carrier or a transfer sheet. The endless belt includes a front-side reinforcing member and a rear-side reinforcing member, and a guide member for preventing meandering fixed over an approximately entire circumference on the rear-side reinforcing member. The extending rollers include a step portion provided in an end area in an axial direction facing to the rear-side reinforcing member, which has a diameter smaller than a center area in the axial direction. The front-side reinforcing member has a width wider than a width of the rear-side reinforcing member.

Abstract: A transfer device including a first combination including an intermediate transfer medium and a transfer member applying a transfer bias, and/or a second combination including an intermediate transfer medium, a second transfer member applying a second transfer bias, and an opposing member configured to transfer the toner image on the intermediate transfer medium to a receiving material at a second transfer nip. When the first combination is subjected to 60-second application of a voltage of 1 kV, followed by discharging, 300 times, the absolute value of logarithmic difference between first and 300th combined volume resistivities is not greater than 0.8 log(?·cm)]. When the second combination is subjected to 60-second application of a voltage of ?1 kV, followed by discharging, 300 times, the absolute value of logarithmic difference between the first and 300th combined volume resistivities is not greater than 0.5 [log?·cm)].

Abstract: An image forming apparatus includes an image carrier, an endless belt whose front surface contacts the image carrier to form a transfer nip, and a bias applying roller configured to apply a transfer bias to a back surface of the endless belt. An image is formed of a toner having an additive embedded rate of not less than 40 percent and including a mother particle having a binder resin and a colorant, and an external additive. The bias applying roller is located so as to satisfy a relationship, L>(A/2)+(B/2)+C, where A is a diameter of the image carrier, B is a diameter of the bias applying roller, C is a thickness of the endless belt, and L is a distance between centers of the image carrier and the bias applying roller on a virtual plane perpendicular to an axis direction of the image carrier.

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: A belt member is formed in an annular shape, which enables endless circulation of the belt member, and includes a belt base; a mark that is formed with a light reflective material; and a protection layer that is formed with a translucent material. The protection layer covers the mark, and the mark and the protection layer are arranged on a surface of the belt member on an inner side of the annular shape.

Abstract: An image forming apparatus includes an image bearing member, supporting rollers, a belt-like-shaped medium, a primary transfer member, secondary transfer rollers, and a grounded conductive roller. The image bearing member forms a toner image at a predetermined process speed. The belt-shaped medium has a charge voltage. The primary transfer member sequentially transfers the toner image onto the belt-like-shaped medium and the secondary transfer member transfers the toner image onto a recording sheet. The conductive roller is arranged in contact with the belt-shaped medium for a predetermined wrapping length. A relationship Tb<X/Vb is satisfied, where Tb is a decay time period that the charge voltage of the belt-shaped medium decays from approximately 200 volts to 200/e volts, where e is a base of natural logarithm, X is the predetermined wrapping length of the belt-shaped medium against the conductive roller, and Vb is the predetermined process speed.

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: An image forming apparatus of the present invention disclosed is of the type sequentially transferring toner images from a plurality of photoconductive drums to a sheet being conveyed by an image transfer belt or an intermediate image transfer belt one above the other with bias applying members to thereby form a composite color image. Backup rollers, contacting the inside surface of the belt, each have volumetric resistivity of 109 ?·cm or above and ten-point mean surface roughness Rz of 6 ?m or above.

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 device includes an endless belt, an external roller, and an internal roller. The external roller is arranged outside of the loop of the endless belt and the inner roller is arranged inside of the loop of the endless belt. The endless belt is sandwiched between the external roller and the internal roller. A surface hardness of the external roller and a surface hardness of the internal roller are 50 degrees or more in an asker C scale. A logarithm (LogR) of volume resistivity of the intermediate transfer member is 10.0 or less.

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 an intermediate transfer belt to which a toner image is transferred from an image carrier. A transfer roller contacts the intermediate transfer belt, forming a nip for image transfer. The transfer roller causes the toner image to be transferred from the intermediate transfer belt to a recording medium at the nip. A first and a second guide member cooperate to guide the recording medium to the nip. The end of the second guide member is positioned at the intermediate transfer belt side with respect to a line connecting a restriction point included in the first guide member and the inlet of the nip. A portion of the recording medium rearward of a portion entered the nip is bent in a convex configuration. The recording medium therefore surely remains in close contact with the intermediate transfer belt in a region where retransfer is apt to occur.

Abstract: A belt member is formed in an annular shape, which enables endless circulation of the belt member, and includes a belt base; a mark that is formed with a light reflective material; and a protection layer that is formed with a translucent material. The protection layer covers the mark, and the mark and the protection layer are arranged on a surface of the belt member on an inner side of the annular shape.