Abstract: An image forming apparatus including: a conveyance unit including a belt member stretched across at least a drive roller and a driven roller and conveys a recording medium and a casing that axially supports the drive roller and the driven roller; a body frame disposed with an image carrier for transferring an image to the recording medium; and a cover to which the conveyance unit is attached, is pivotably attached to the body frame, and opens/closes off the image carrier. A first regulating portion against which an annular member placed on a shaft portion of the drive roller abuts when the cover pivots toward the body frame to close off the image carrier and a second regulating portion with which an engagement portion formed in the casing in a direction orthogonal to the axial direction of the drive roller engages are formed on the body frame.

Abstract: An image forming apparatus which includes an image carrier holding toner images of plural colors, and a transfer portion that transfers the toner images of plural of colors held on the image carrier onto a recording medium, wherein the image carrier is rotatablly disposed toward the image carrier and has elasticity in a rotating direction toward the image carrier, has a pattern image forming unit repeatedly forming a pattern image for color misregistration detection on the image carrier at a constant interval so as to set the pattern images within a length range of the recording medium, wherein one of the pattern images includes a first toner image group in which plural toner images of a first color is formed at a first interval, and a second toner image group in which plural toner images of a second color is formed at a second interval.

Abstract: An image forming apparatus includes a photoreceptor, a driving unit which rotation-drives the photoreceptor, an exposure unit which forms a latent image by performing image exposure to the photoreceptor, a plurality of development units which develop a plurality of latent images sequentially formed on the photoreceptor with different color toners respectively, a belt-like intermediate transfer member onto which respective color toner images sequentially developed on the photoreceptor are primarily transferred to be superimposed on each other, at least one load unit which comes in contact with or is separated from the belt-like intermediate transfer member to change a load on the belt-like intermediate transfer member, and a speed control unit which increases/decreases a driving speed of the photoreceptor at a specified timing. Preferably, the belt-like intermediate transfer member is an elastic belt.

Abstract: In an image forming apparatus using an electro-photographic technique and having an endless belt-shaped photosensitive body for transferring images, a mechanism is provided to maintain the photosensitive body at a constant transfer speed over its entire length irrespective of the effects of various devices in contact with it. A driving roller drives the photosensitive body by contacting its rear surface. One or more guide rollers are also in contact with the rear surface of the photosensitive body for guiding it in conjunction with the driving roller. A transmission such as a belt and pulley or gear mechanism transmits driving force from the driving roller to one or more of the guide rollers. When at least two guide rollers are provided, one is disposed between and above the driving roller and the second guide roller. The driving roller and the second guide roller are so disposed that the portion of the photosensitive body between them lies in a horizontal plane.

Abstract: In an image forming apparatus using an electro-photographic technique and having an endless belt-shaped photosensitive body for transferring images, a mechanism is provided to maintain the photosensitive body at a constant transfer speed over its entire length irrespective of the effects of various devices in contact with it. A driving roller drives the photosensitive body by contacting its rear surface. One or more guide rollers are also in contact with the rear surface of the photosensitive body for guiding it in conjunction with the driving roller. A transmission such as a belt and pulley or gear mechanism transmits driving force from the driving roller to one or more of the guide rollers. When at least two guide rollers are provided, one is disposed between and above the driving roller and the second guide roller. The driving roller and the second guide roller are so disposed that the portion of the photosensitive body between them lies in a horizontal plane.