Image forming apparatus

摘要

An image forming apparatus including an image forming unit, a conveyance roller, a registration roller disposed on a conveyance path extending from the conveyance roller to the image forming unit, the registration roller being configured to perform skew correction for a sheet by contacting a leading end of the sheet in a conveyance direction while rotation of the registration roller is being stopped, and rotating after a lapse of a particular period of time since the rotation of the registration roller has been stopped, a driving source configured to supply a driving force to the conveyance roller and the registration roller, and a controller configured to determine the particular period of time based on a cumulative number of sheets conveyed by the conveyance roller.

主权项

1. An image forming apparatus comprising:
an image forming unit configured to form an image on a sheet; a conveyance roller configured to convey the sheet in a conveyance direction toward the image forming unit; a downstream sheet detector disposed downstream of the conveyance roller in the conveyance direction, the downstream sheet detector being configured to output a signal according to whether the downstream sheet detector detects the sheet; a registration roller disposed downstream of the downstream sheet detector and upstream of the image forming unit in the conveyance direction; a driving source configured to supply a driving force to the conveyance roller and the registration roller; an upstream sheet detector disposed upstream of the conveyance roller in the conveyance direction, the upstream sheet detector being configured to output a signal according to whether the upstream sheet detector detects the sheet; a controller configured to perform:
a skew correction process comprising:
feeding the sheet by rotating the conveyance roller;in response to the downstream sheet detector detecting the sheet, stopping rotation of the registration roller and causing a leading end of the sheet in the conveyance direction to contact the stopped registration roller; andstarting rotation of the registration roller after a lapse of a particular period of time since the rotation of the registration roller has been stopped, and conveying the sheet in the conveyance direction by the registration roller; anda determining process comprising:
counting the cumulative number of sheets conveyed by the conveyance roller, using the signal output from the upstream sheet detector, anddetermining the particular period of time based on the cumulative number of sheets conveyed by the conveyance roller.