An image forming apparatus includes a rotating body to form an image, a sensor to detect a home position of the rotating body, a processor to acquire image density data of the image formed by the rotating body in odd-numbered rotation and even-numbered rotation of the rotating body separately based on a rotation home position signal output by the sensor, extract an image density fluctuation caused by a rotation of the rotating body, and correct an image forming condition based on the image density fluctuation.

A driving device is used in an image reading apparatus, and reciprocates a scanning unit for reading an image on an original. The driving device comprises a pull member, a driving pulley which transmits driving force to the pull member, a following pulley which applies tension to the pull member and a pulley holder having a pulley axis which holds the following pulley rotatably. Then, the pulley axis has a lock pawl capable of locking an upper end portion of the following pulley and canceling engagement with the following pulley by being tilted toward a side of an axial center by elastic deformation. Furthermore, the lock pawl is arranged at a side of a tension acting direction from the pull member to the following pulley except the farthest position from the driving pulley among positions in a circumferential direction of the pulley axis. It is possible to attach and detach the following pulley easily at a time of maintenance or the like.

A driving device is used in an image reading apparatus, and reciprocates a scanning unit for reading an image on an original. The driving device comprises a pull member, a driving pulley which transmits driving force to the pull member, a following pulley which applies tension to the pull member and a pulley holder having a pulley axis which holds the following pulley rotatably. Then, the pulley axis has a lock pawl capable of locking an upper end portion of the following pulley and canceling engagement with the following pulley by being tilted toward a side of an axial center by elastic deformation. Furthermore, the lock pawl is arranged at a side of a tension acting direction from the pull member to the following pulley except the farthest position from the driving pulley among positions in a circumferential direction of the pulley axis. It is possible to attach and detach the following pulley easily at a time of maintenance or the like.

A sheet conveyance apparatus conveying a sheet includes a conveyance roller and first and second rotary members. A first virtual line and a second virtual line cross each other when viewed in the rotation axis direction of the conveyance roller, with the first virtual line passing through the rotation center of a first longitudinal end of the first rotary member and a rotation center of a second longitudinal end of the first rotary member when viewed in the rotation axis direction of the conveyance roller. A second virtual line passes through the rotation center of a third longitudinal end of the second rotary member and the rotation center of a fourth longitudinal end of the second rotary member when viewed in the rotation axis direction of the conveyance roller.

A sheet conveyance apparatus conveying a sheet includes a conveyance roller and first and second rotary members. A first virtual line and a second virtual line cross each other when viewed in the rotation axis direction of the conveyance roller, with the first virtual line passing through the rotation center of a first longitudinal end of the first rotary member and a rotation center of a second longitudinal end of the first rotary member when viewed in the rotation axis direction of the conveyance roller. A second virtual line passes through the rotation center of a third longitudinal end of the second rotary member and the rotation center of a fourth longitudinal end of the second rotary member when viewed in the rotation axis direction of the conveyance roller.

A three dimensional scanner assembly for producing a two dimensional print of a three dimensional object includes a scanning panel that is positioned on a copying machine. The scanning panel is comprised of a resiliently flexible material. In this way the scanning panel can conform to the curvature of a rounded or otherwise bulky object thereby facilitating the copying machine to scan a majority of an outer surface of the rounded or otherwise bulky object. Thus, the copying machine is facilitated to reproduce a two dimensional print of a three dimensional object in a single scan. A lid panel is positioned on a scanning lid of the copying machine and the lid panel is positioned on top of the object that is placed on the scanning panel.

According to aspects of the embodiments, there is provided process and architecture for enabling multiple digital micromirror devices (DMDs) that include optical modulation elements configured to modulate light outputting from a light source, and a projection unit configured to project light modulated by the optical modulation elements on a printing plate. Image defects due to misalignment in the cross-process direction of the output from the DMDs are discovered by using a single test pattern image and combined with knowledge of how individual pixels are rendered to register printing elements which can render a variable number of pixels. Misalignment errors can be corrected by selecting a different set of mirrors for a given DMD.

An image forming apparatus includes a first temperature sensor inside the image forming apparatus and configured to detect a temperature. A controller is configured to execute a first position shift correction for each of a plurality of toner images used in printing an image when the first temperature sensor detects a change in temperature from a previously detected temperature exceeds a first threshold value set for a first temperature range. After the first position shift correction, the controller executes a second position shift correction if the detected change exceeds a second threshold value set for a second temperature range higher than the first temperature range and the temperature is outside a prescribed temperature range, and skips the second position shift correction otherwise.

A scanner has a first mirror having a plurality of concavities configured to reflect light from a document; and a sensor configured to detect light reflected by the concavity; the concavity having an optical characteristic that differs according to position.

A seal member is injection-molded with a simple structure that needs no complicated assembling process. An optical scanning device 21 includes a light source unit 202 from which a light beam is emitted; a rotating polygon mirror 203 that deflects the light beam such that the light beam emitted from the light source unit 202 is scanned over a photosensitive member; an optical component that directs the light beam deflected by the rotating polygon mirror 203 onto the photosensitive member; an optical housing 20 that contains the light source unit 202, the rotating polygon mirror 203, and the optical component; and a cover 30 that covers an opening of the optical housing 20. The cover 30 includes a seal member 31a molded such that the seal member 31a is sandwiched between the cover 30 and a side wall of the optical housing 20, a gate 31a from which hot melt is injected, and a channel through which the hot melt flows to form the seal member 31a such that the seal member 31a is sandwiched between the side wall of the optical housing 20 and the cover 30. The gate 31a is provided outside a light path area for the light beam when viewed in a direction of a rotational axis of the rotating polygon mirror 203.