Image forming apparatus adapted to feed continuous rolled-sheet paper by controlling slack in the paper for the accurate cutting thereof

摘要

An image forming apparatus capable of cutting a strip-shaped continuous sheet on which an image is formed to a desirable cutting length. A rolled-sheet is conveyed by registration rollers and the like. The rolled-sheet is further led to the vicinity of a photosensitive drum through pre-transfer rollers. The rolled-sheet to which a toner image has been transferred is subjected to toner fixing processing by a fixing device. When the leading end of the rolled-sheet reaches the pre-transfer rollers, the rotational speed of a sheet feeding motor is increased during a predetermined time. Consequently, the sheet conveying speed on the upstream side of the pre-transfer rollers in a direction of sheet conveyance is increased, thereby forming slack in a sheet portion between the registration rollers and the pre-transfer rollers. Consequently, tension exerted on a sheet portion between the fixing device and the pre-transfer rollers does not affect the conveyance of the sheet by the registration rollers. If operation timing of a cutting mechanism is determined on the basis of the number of output pulses of a pulse output unit for detecting rotation of the sheet feeding motor, therefore, the rolled-sheet can be reliably cut to a desirable length.