Abstract: An image forming apparatus includes an image carrier, a toner-image forming unit, a photosensor, an information obtaining unit, and a toner-amount calculating unit. The toner-image forming unit forms a toner image on the image carrier with toner. The photosensor detects a toner area where the toner is sticking to the image carrier. The information obtaining unit obtains particle-size-change information about how particle size distribution of the toner changes over time. The toner-amount calculating unit calculates a toner amount of the toner image based on the toner area and the particle-size-change information.

Abstract: An image forming unit includes four photoconductors, a belt extended around a driving roller and an extension-cum-primary transfer roller. Three primary transfer rollers sandwich the belt in association with a corresponding photoconductor. The extension-cum-primary transfer roller serves both as an extension roller and a primary transfer roller.

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: Latent images of different colors are superimposed on an intermediate transfer belt of an endless type from image carriers, to form a full color toner image. A tension roller maintains a tension of the intermediate transfer belt. A driving roller drives the intermediate transfer belt. A biasing unit applies the tension to the tension roller. A holding unit holds the tension roller. An image reading sensor detects the toner image formed on the intermediate transfer belt. The image reading sensor is disposed in the holding unit, in an opposite position to the tension roller with respect to the intermediate transfer belt.

Abstract: Latent images of different colors are superimposed on an intermediate transfer belt of an endless type from image carriers, to form a full color toner image. A tension roller maintains a tension of the intermediate transfer belt. A driving roller drives the intermediate transfer belt. A biasing unit applies the tension to the tension roller. A holding unit holds the tension roller. An image reading sensor detects the toner image formed on the intermediate transfer belt. The image reading sensor is disposed in the holding unit, in an opposite position to the tension roller with respect to the intermediate transfer belt.

Abstract: An image forming apparatus of the present invention includes a plurality of image carriers arranged side by side and a charging device, exposing device and developing device arranged around each image carrier. An image transferring unit includes an image transfer belt and a plurality of bias applying members for applying image transfer biases to image transfer nips formed between the bias applying members and the image carriers, which face each other with the intermediary of the image transfer belt. Each image transferring member has an axis positioned downstream, in the direction of movement of the image transfer belt, of a virtual vertical line extending from the axis of the associated image carrier downward. At least two of the bias applying members are provided with respective belt holding members at the downstream side in the direction of movement of the image transfer belt.

Abstract: A primary transfer unit includes transfer units for performing a toner transfer from image carriers onto a transfer belt. Each of the transfer units is formed with a metallic roller. The metallic roller is arranged so as to satisfy ?1<?2, where an angle of the endless belt with respect to a tangent to the image carrier, on a side upstream of rotation of the endless belt to a transfer nip region where the image carrier and the endless belt are in contact is ?1, and an angle of the endless belt with respect to the tangent, on a side downstream of rotation of the endless belt to the transfer nip region is ?2.

Abstract: A toner consumption-calculating apparatus includes a printed portion area-detecting unit that detects an area of a printed portion of image data of a latent image that is formed on a latent image-bearing member; a latent image portion area-detecting unit that detects an area of a latent image portion on the latent image-bearing member; and a latent image portion toner consumption-calculating unit that calculates latent image portion toner consumption that indicates toner amount that is consumed due to adhering on the latent image portion. The latent image portion toner consumption-calculating unit uses a detection result of the latent image portion area-detecting unit and a detection result of the printed portion area-detecting unit to calculate the latent image portion toner consumption.

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: Latent images of different colors are superimposed on an intermediate transfer belt of an endless type from image carriers, to form a full color toner image. A tension roller maintains a tension of the intermediate transfer belt. A driving roller drives the intermediate transfer belt. A biasing unit applies the tension to the tension roller. A holding unit holds the tension roller. An image reading sensor detects the toner image formed on the intermediate transfer belt. The image reading sensor is disposed in the holding unit, in an opposite position to the tension roller with respect to the intermediate transfer belt.

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: An electrophotographic color image forming apparatus of the present invention includes a plurality of image forming sections each including an image carrier and image transferring means. Toner images of different colors are sequentially transferred from the image carriers to a sheet being conveyed by an endless belt while electrostatically adhering to the belt, completing a color toner image. Assuming that the surface of each image carrier and that of the belt move at speeds of Vd and Vb, respectively, a ratio of Vb/Vd can be varied by the user of the apparatus. In addition, assuming that a surface of an intermediate transferring mechanism and a surface of a recording medium move at speeds of Vp and Vi, respectively, the ratio of Vp/Vi can be varied by the user.

Abstract: An image forming unit includes four photoconductors, a belt extended around a driving roller and an extension-cum-primary transfer roller. Three primary transfer rollers sandwich the belt in association with a corresponding photoconductor. The extension-cum-primary transfer roller serves both as an extension roller and a primary transfer roller.

Abstract: A primary transfer unit includes transfer units for performing a toner transfer from image carriers onto a transfer belt. Each of the transfer units is formed with a metallic roller. The metallic roller is arranged so as to satisfy ?1<?2, where an angle of the endless belt with respect to a tangent to the image carrier, on a side upstream of rotation of the endless belt to a transfer nip region where the image carrier and the endless belt are in contact is ?1, and an angle of the endless belt with respect to the tangent, on a side downstream of rotation of the endless belt to the transfer nip region is ?2.

Abstract: In an image forming apparatus, an intermediate transfer belt is made of a resin film and is supported by a plurality of rollers. A driving roller that is one of the plurality of rollers, drives the intermediate transfer belt, and also functions as an opposing unit with respect to a secondary transfer roller. The driving roller is made of metal, and applies a bias to at least secondary transfer units, at least at a time of performing primary transfer to a plurality of image bearing bodies.

Abstract: An image forming apparatus of the present invention includes a plurality of image carriers arranged side by side and charging means, exposing means and developing means arranged around each image carrier. An image transferring unit includes an image transfer belt and a plurality of bias applying members for applying image transfer biases to image transfer nips formed between the bias applying members and the image carriers, which face each other with the intermediary of the image transfer belt. Each image transferring member has an axis positioned downstream, in the direction of movement of the image transfer belt, of a virtual vertical line extending from the axis of the associated image carrier downward. At least two of the bias applying members are provided with respective belt holding members at the downstream side in the direction of movement of the image transfer belt.

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.