Abstract: An image forming apparatus conveying a recording medium through a sheet conveying path may include a recording medium conveying device, and includes an edge position detector to detect a position of a side edge of a recording medium along a width direction perpendicular to a sheet travel direction of the recording medium in the sheet conveying path, and an edge position recognizer to recognize, based on detection results obtained by the edge position detector, the position of the side edge at multiple detection positions of the recording medium in the sheet travel direction of the recording medium. The multiple detection positions includes a detection position located within a dog ear region in the vicinity of either a leading edge or a trailing edge of the recording medium in the sheet travel direction.

Abstract: An image forming apparatus includes an image forming mechanism, a sheet conveyance mechanism, and a sheet detector. The image forming mechanism forms an image and transfers it onto the sheet conveyed by the sheet conveyance mechanism. The sheet detector is arranged upstream from an image transfer region and configured to detect the sheet. The sheet detector includes a light source, a plurality of photoreceptors, and a controller. The plurality of photoreceptors is arranged in line in a main-scanning direction and includes a first photoreceptor group and a second photoreceptor group. The first photoreceptor group changes output voltages when overridden by the side edge of the sheet. The second photoreceptor group includes an opposite end of the plurality of photoreceptors being out of the side edge of the sheet. The controller is configured to adjust a light emission amount in accordance with characteristics of the sheet.

Abstract: An image forming apparatus conveying a recording medium through a sheet conveying path may include a recording medium conveying device, and includes an edge position detector to detect a position of a side edge of a recording medium along a width direction perpendicular to a sheet travel direction of the recording medium in the sheet conveying path, and an edge position recognizer to recognize, based on detection results obtained by the edge position detector, the position of the side edge at multiple detection positions of the recording medium in the sheet travel direction of the recording medium. The multiple detection positions includes a detection position located within a dog ear region in the vicinity of either a leading edge or a trailing edge of the recording medium in the sheet travel direction.

Abstract: A sheet detector, a sheet detector mechanism and an image forming apparatus. An image forming apparatus may include an image forming mechanism, a sheet conveyance mechanism, and a sheet detector. The image forming mechanism may form an image and transfer the image onto the sheet conveyed by the sheet conveyance mechanism. The sheet detector may be arranged upstream from an image transfer region and configured to detect the sheet. The sheet detector may include a light source emitting light, a plurality of photoreceptors, and a controller. The plurality of photoreceptors may be arranged in a line in a main-scanning direction and may include a first photoreceptor group and a second photoreceptor group. The first photoreceptor group may change output voltages when overridden by the side edge of the sheet. The second photoreceptor group may include an opposite end of the plurality of photoreceptors being out of the side edge of the sheet.

Abstract: An image forming apparatus includes a sheet feed unit having a sheet feed port, an image forming unit, a sheet position detector, a mode selector, and a memory unit. The sheet feed unit feeds a recording sheet. The image forming unit forms an image on the recording sheet. The sheet position detector detects a sheet edge of the recording sheet. The mode selector selects at least one of the position correction mode and non-correction mode for the sheet feed port. An image forming position on the recording sheet is corrected using position information detected by the sheet position detector when the position correction mode is selected, and the image forming position on the recording sheet is not corrected when the non-correction mode is selected. A memory unit may store a plurality of values of light intensity and threshold value corresponding to different types of recording sheets.

Abstract: A pair of grip rollers forming a slack in a transfer sheet by impinging the transfer sheet against a pair of registration rollers that are at a standstill, includes a one-way rotating clutch. A coil spring biases the one-way rotating clutch such that projections on a flange of the one-way rotating clutch engage with holes on a rear sideboard. When a transfer sheet caught by the pair of grip rollers is pulled out with a predetermined or greater torque in an opposite direction to that in which the transfer sheet is conveyed, the projections are disengaged with the holes, against the coil spring bias. Thereby the one-way clutch is set free and can be rotated in a reverse direction.

Abstract: A duplex unit includes a case housing a sheet reverse path that connects to a sheet discharging outlet and a sheet refeed inlet provided on a side of a main body case housing an image forming unit and that is configured to reverse the sheet supplied from the sheet discharging outlet and refeed the sheet to the sheet refeed inlet. The case is rotatable around a first supporting shaft so as to be opened and closed. The duplex unit includes a manual sheet feeding tray that is rotatably supported by a horizontal second supporting shaft so as to be opened to manually feed a sheet to a manual sheet feeding inlet provided on the side of the main body case and to be closed otherwise. A recess is provided on the case so as to retract the manual sheet feeding tray into the recess without protruding from a side surface of the case when the tray is closed. The case and the manual sheet feeding tray are engaged by engaging a concave portion of the case and a convex portion of the manual sheet feeding tray.

Abstract: A paper sheet separating apparatus has a feeding roller to feed a paper sheet in a transporting direction and a reversing roller to give a predetermined torque in the opposite direction to the transporting direction so that paper sheets are separated and fed one by one from accommodated paper sheets. The paper sheet separating apparatus includes a reversing roller mounted on a reverse shaft via a torque limiter. The torque limiter includes a clutch body which rotates integrally with the reverse shaft, a hub which is rotatably supported on the shaft and a spring which is disposed between the clutch body and the hub. The hub forms a part of the reversing roller.

Abstract: A sheet feed device for image forming equipment and capable of feeding sheets one by one from a stack by separating them. The device has a flat plate including a dielectric portion which is capable of making surface-to-surface content with the top of the stack, a means for moving the plate in a reciprocating motion, a means for moving the plate into and out of contact with the stack, and a means for applying a voltage to the plate to cause it to exert an electrostatic adhering force.

Abstract: A sheet feed device for image forming equipment and capable of feeding sheets one by one from a stack by separating them. The device has a flat plate including a dielectric portion which is capable of making surface-to-surface content with the top of the stack, a unit for moving the plate in a reciprocating motion, a unit for moving the plate into and out of contact with the stack, and a unit for applying a voltage to the plate to cause it to exert an electrostatic adhering force.

Abstract: The present invention relates to an apparatus for feeding sheets separately, the apparatus comprises a feed unit disposed over a stack of sheets for causing a conveyance force upon the uppermost of the stack thereby to feed the uppermost sheet from the stack with the conveyance force being directed in a sheet path direction. The feed unit has an alternating charged pattern on a surface thereof. The apparatus further comprises a separation unit disposed opposite to the feed unit so as to form a sheet path in association with the feed unit for causing a preventive force onto an under face of the fed sheet thereby to prevent the sheet from being fed. The preventive force is set to be less than the conveyance force and greater than a friction force between sheets. The separation unit has another alternating charged pattern on a surface thereof.

Abstract: A sheet feeding and separting device incorporated in image forming equipment for feeding sheets one by one from a sheet stack while preventing two or more sheets from being fed together as far as possible and, when a plurality of sheets are accidentally fed together, surely separating one of them from the others. A pick-up member is implemented as an endless dielectric belt. An AC power source forms a charge pattern on the belt via an electrode. As a result, the belt retains a sheet by attraction and transports it due to the Maxwell stress generated in the sheet. When a plurality of sheets are fed together, an arresting member which faces the belt separates one of them from the others. Alternatively, a charge pattern may be formed on the surface of the arresting member.

Abstract: A sheet feeding and separating device incorporated in image forming equipment for feeding sheets one by one from a sheet stack while preventing two or more sheets from being fed together as far as possible and, when a plurality of sheets are accidentally fed together, surely separating one of them from the others. A pick-up member is implemented as an endless dielectric belt. An AC power source forms a charge pattern on the belt via an electrode. As a result, the belt retains a sheet by attraction and transports it due to the Maxwell stress generated in the sheet. When a plurality of sheets are fed together, an arresting member which faces the belt separates one of them from the others. Alternatively, a charge pattern may be formed on the surface of the arresting member.