Abstract: An image forming apparatus having: an image forming body for forming a latent image and a toner image; a developing device for developing with a toner the latent image formed on the image forming body to form the toner image; a primary transfer device for transferring the toner image on the image forming body onto an intermediate transfer body; and a secondary transfer device for transferring the toner image on the intermediate transfer body onto an image support. The primary transfer device has conductive body or semi-conductive body, and is provided with a power supply unit for applying a bias voltage. It is characterized in that the variation coefficient of the shape factor of the toner is 16% or less, and the number variation coefficient of the number particle size distribution of the toner is 27% or less.

Abstract: An image forming apparatus having: a transfer section which transfers a toner image onto an intermediate transfer body or a transfer material to form an image thereon; a selection section for selecting one mode among a plurality of modes including a first mode for forming the image by using a plurality of colors including a first color and a second mode for forming the image by using less number of colors including the first color than that of the colors in the first mode; and a control section for controlling the transfer section in order that a transfer rate of a toner image of the first color in the second mode is larger than that of a toner image of the first color in the first mode when toner images are transferred onto the intermediate transfer body or the transfer material by the transfer section.

Abstract: An image forming apparatus having therein an image carrier, an intermediate transfer belt is trained about plural rollers and is located at a position where it comes in contact with the image carrier, a primary transfer roller that is arranged to face the image carrier through the intermediate belt for the purpose of transferring toner on the image carrier onto the intermediate transfer belt, wherein the following expression holds when Ft (kgf) represents tension of the intermediate transfer belt, Fr (kgf) represents pressing force of primary transfer roller and d (mm) represents a shift amount for the image carrier and the primary transfer roller, Fr?(0.05×Ft+0.11)×d?0.3.

Abstract: An image forming apparatus having: a transfer section which transfers a toner image onto an intermediate transfer body or a transfer material to form an image thereon; a selection section for selecting one mode among a plurality of modes including a first mode for forming the image by using a plurality of colors including a first color and a second mode for forming the image by using less number of colors including the first color than that of the colors in the first mode; and a control section for controlling the transfer section in order that a transfer rate of a toner image of the first color in the second mode is larger than that of a toner image of the first color in the first mode when toner images are transferred onto the intermediate transfer body or the transfer material by the transfer section.

Abstract: An image forming apparatus having therein an image carrier, an intermediate transfer belt is trained about plural rollers and is located at a position where it comes in contact with the image carrier, a primary transfer roller that is arranged to face the image carrier through the intermediate belt for the purpose of transferring toner on the image carrier onto the intermediate transfer belt, wherein the following expression holds when Ft (kgf) represents tension of the intermediate transfer belt, Fr (kgf) represents pressing force of primary transfer roller and d (mm) represents a shift amount for the image carrier and the primary transfer roller,

Abstract: An image forming apparatus, which includes a photoreceptor having a substrate whose surface having been subjected to a surface processing with a cutting tool, and a photosensitive layer formed on the substrate; an exposure device for exposing an image on the photoreceptor to form a latent image, having a light source for emitting a light beam, and carrying out exposure in a manner of dot arrangement through a main scanning by the deflection of the light beam and a sub-scanning by a movement of the photoreceptor; a developing device; and a transfer device. The apparatus is characterized in that the exposure device carries out scanning exposure with a spatial frequency of dot arrangement pitch of not less than 4 dots/mm in the main scanning direction, and surface roughness Rz of the substrate in the main scanning direction is not greater than 1.5 &mgr;m.

Abstract: This invention relates to an image forming apparatus. The image forming apparatus includes a primary transfer means for bringing one surface of an intermediate transfer body and/or transfer medium into contact with a photosensitive body surface and pressing the surface against the photosensitive body surface to transfer a toner image formed on the photosensitive body surface onto one surface of the intermediate transfer body and/or transfer medium.

Abstract: According to the present invention, there is provided an image forming apparatus including developing units which develop latent images formed on image carriers for colors of yellow, magenta, cyan, and black using toners of the corresponding colors, transfer units which transfer toner images in the respective colors formed on the image carriers onto the same transfer body, and a fixing unit which fixes the toner images, and toner preferably used in the image forming apparatus. The developing unit performs development using toner in which, out of five materials of silica, titania, barium sulfate, fine polymer particles, and a lubricant, materials not including either fine polymer particles or barium sulfate are fixed as an external additive, in order to avoid poor transfer and toner filming, improve the cleaning properties, and form an excellent image.

Abstract: This invention relates to an image forming apparatus. The image forming apparatus includes a primary transfer means for bringing one surface of an intermediate transfer body and/or transfer medium into contact with a photosensitive body surface and pressing the surface against the photosensitive body surface to transfer a toner image formed on the photosensitive body surface onto one surface of the intermediate transfer body and/or transfer medium.

Abstract: A developing device for developing a static latent image is disclosed. The relation between an average of the circle corresponding diameter of the toner aggregates in the toner image on the image carrier surface formed by developing the static latent image and a value obtained by dividing the standard deviation of a circle corresponding diameter of the toner aggregate by the average circle corresponding diameter of the toner aggregates satisfies following Formula 1. 0<Y<179.01×X−1.9031 wherein X is a diameter of the circle corresponding to toner aggregate in &mgr;m (X>20 &mgr;m), and Y is CV1, CV1=Standard deviation of the circle corresponding diameter of the toner aggregate/Average of the circle corresponding diameter of the toner aggregates X.

Abstract: An image forming apparatus, which includes a photoreceptor having a substrate whose surface having been subjected to a surface processing with a cutting tool, and a photosensitive layer formed on the substrate; an exposure device for exposing an image on the photoreceptor to form a latent image, having a light source for emitting a light beam, and carrying out exposure in a manner of dot arrangement through a main scanning by the deflection of the light beam and a sub-scanning by a movement of the photoreceptor; a developing device; and a transfer device. The apparatus is characterized in that the exposure device carries out scanning exposure with a spatial frequency of dot arrangement pitch of not less than 4 dots/mm in the main scanning direction, and surface roughness Rz of the substrate in the main scanning direction is not greater than 1.5 &mgr;m.

Abstract: An image forming apparatus having: an image forming body for forming a latent image and a toner image; a developing device for developing with a toner the latent image formed on the image forming body to form the toner image; a primary transfer device for transferring the toner image on the image forming body onto an intermediate transfer body; and a secondary transfer device for transferring the toner image on the intermediate transfer body onto an image support. The primary transfer device has conductive body or semiconductive body, and is provided with a power supply unit for applying a bias voltage. It is characterized in that the variation coefficient of the shape factor of the toner is 16% or less, and the number variation coefficient of the number particle size distribution of the toner is 27% or less.

Abstract: A developing device for developing a static latent image is disclosed. The relation between an average of the circle corresponding diameter of the toner aggregates in the toner image on the image carrier surface formed by developing the static latent image and a value obtained by dividing the standard deviation of a circle corresponding diameter of the toner aggregate by the average circle corresponding diameter of the toner aggregates satisfies following Formula 1.

Abstract: An image forming apparatus, including: a charger, arranged around an image carrier, for charging a surface of the image carrier; an exposure device, arranged around the image carrier, for exposing the surface of the image carrier, after it is charged by the charger, and for forming an electrostatic latent image on the surface of the image carrier; a developer device, having a developer carrier and arranged around the image carrier, for carrying developer with which the electrostatic latent image is developed so as to obtain a developed image; and a transfer device, arranged around the image carrier, for transferring the developed image onto a transfer material.

Abstract: In a non-contact development with a two component type developer composed of toner particles and resin-coated tic carrier particles, the resin-coated magnetic carrier particles have a specific electric resistance of 10.sup.5 .OMEGA..multidot.cm to 10.sup.12 .OMEGA..multidot.cm, and a strength of magnetic field on a surface of a cylindrical developing sleeve at the closest position between cylindrical developing sleeve and a photoreceptor drum in a developing region is 1000 G(gauss) to 2500 G.