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: An image forming apparatus includes plural image forming devices each including an image carrier, a charger and a developing device, which in conjunction produce a corresponding toner image on the image carrier. A primary image transferring device transfers the toner images from the image carriers to an intermediate image transfer body one above the other, thereby forming a composite toner image. A secondary image transferring device transfers the composite toner image from the intermediate image transfer body to a recording medium. The primary image transferring device includes the intermediate image transfer body including at least an elastic layer, a cleaning device cleaning the intermediate image transfer body, and a coating device coating a lubricant on the intermediate image transfer body. The charger is released from the image carrier substantially at the same time as the coating device is released from the intermediate image transfer body.

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 an intermediate image transfer belt to which a toner image is to be transferred from an image carrier, an image transferring device for transferring the toner image from the intermediate image transfer belt to a sheet, and a fixing device for fixing the toner image on the sheet. When the length of the sheet in the direction of conveyance is smaller than a distance between the image transferring device and the fixing device, a matching circuit varies only the speeds of the image transferring device and fixing device, but does not vary the speed of a device that executes a step preceding the image transfer step. The matching device then sets an interval between consecutive sheets matching with the varied speeds of the image transferring device and fixing device, thereby matching opposite sides with respect to the image transfer step to each other as to the number of sheets to be conveyed.

Abstract: An image forming apparatus including an intermediate transfer body for carrying a color image, a transferring device for conveying a recording medium while causing the recording medium to bend toward and move along a part of the intermediate transfer body at an upstream side in a direction of conveyance in a transfer region in which a color image on the intermediate transfer body is transferred to the recording medium, and a contact assisting member positioned upstream of the transfer region in the direction of conveyance for maintaining the recording medium and the intermediate transfer body in close contact with each other.

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 image forming apparatus includes a plurality of image forming devices each including an image carrier, a charger for uniformly charging the surface of the image carrier, and a developing device for developing a latent image formed on the charged surface the image carrier with toner to thereby produce a corresponding toner image. A primary image transferring device transfers such toner images from the image carriers to an intermediate image transfer body one above the other, thereby completing a composite toner image. A secondary image transferring device transfers the composite toner image from the intermediate image transfer body to a recording medium. The primary image transferring vice includes the intermediate image transfer body including at least an elastic layer, a cleaning unit for cleaning the intermediate image transfer body, and a coating member for coating a lubricant on the intermediate image transfer body.

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: An image forming apparatus of the present invention includes a plurality of image forming means each including an image carrier, a charger for uniformly charging the surface of said image carrier, and a developing device for developing a latent image formed on the charged surface of the image carrier with toner to thereby produce a corresponding toner image. A primary image transferring device transfers such toner images from the image carriers to an intermediate image transfer body one above the other, thereby completing a composite toner image. A secondary image transferring device transfers the composite toner image from the intermediate image transfer body to a recording medium. The primary image transferring device includes the intermediate image transfer body including at least an elastic layer, a cleaning unit for cleaning the intermediate image transfer body, and a coating member for coating a lubricant on the intermediate image transfer body.

Abstract: An image forming apparatus of the present invention 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. This configuration causes a port ion of the recording medium rearward of a portion entered the nip to bend in a convex configuration. The recording medium therefore surely remains in close contact with the intermediate transfer belt in a region where pretransfer is apt to occur.

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 &OHgr;·cm or above and ten-point mean surface roughness Rz of 6 &mgr;m or above.

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: An image forming apparatus of the present invention includes an intermediate image transfer belt to which a toner image is to be transferred from an image carrier, an image transferring device for transferring the toner image from the intermediate image transfer belt to a sheet, and a fixing device for fixing the toner image on the sheet. When the length of the sheet in the direction of conveyance is smaller than a distance between the image transferring device and the fixing device, a matching circuit varies only the speeds of the image transferring device and fixing device, but does not vary the speed of a device that executes a step preceding the image transfer step. The matching device then sets an interval between consecutive sheets matching with the varied speeds of the image transferring device and fixing device, thereby matching opposite sides with respect to the image transfer step to each other as to the number of sheets to be conveyed.

Abstract: Monocolor image forming unit includes a developing device and an image carrier cleaning device arranged around an image carrier. A plurality of such the monocolor image forming unit is arrayed laterally along the rotary transport direction of an intermediate transfer member of the belt type to configure a tandem image forming device. In the tandem image forming device, a synthesized toner image is formed on the intermediate transfer member and transferred to a recording medium to form a multicolor image thereon. Among the plurality of monocolor image forming unit contained in the tandem image forming device, at least two monocolor image forming unit each include a toner recycling device for conveying toner collected at the image carrier cleaning device to the developing device.