An image forming apparatus includes an engine to form an image on an image forming medium, a paper transfer device to pick up a printing paper and transfer the paper to a transfer path, a sensor to sense a printing paper at a predetermined position on the transfer path, and a processor to determine whether a transfer delay occurs, when the printing paper is sensed, and adjust a pickup timing to advance a pickup of a printing paper of a next page.

An image forming apparatus includes an image bearing member, a transfer portion configured to transfer an image borne on the image bearing member to a sheet, a current detection portion configured to detect a current flowing through the transfer portion, a conveyance portion configured to convey the sheet to the transfer portion, a driving portion configured to drive the conveyance portion, and a controller configured to acquire an arrival timing at which a leading edge of a preceding sheet has arrived at the transfer portion based on a detection result of the current detection portion, and control the driving portion in response to the arrival timing in a state where a succeeding sheet that follows the preceding sheet is conveyed by the conveyance portion.

Provided is an image forming apparatus including a positioning portion provided upstream of a transfer portion in a transport direction of a recording medium. The positioning portion positions the medium using a leading end of the medium. Additionally included is a detector that is disposed downstream of the positioning portion in the transport direction, and that detects passage of the leading end of the medium; and a controller that controls a transport speed in a period from when the leading end of the medium passes through the detector to when the leading end of the medium passes through a target position situated downstream of the detector in the transport direction, in accordance with a time since transport of the medium is started from the positioning portion until the leading end of the medium passes through the detector.

A sheet housing apparatus including a housing unit, which houses a sheet to be discharged from a discharging opening of a printer, and a pair of housing-side feet disposed on both sides, in a width direction, of the sheet housing apparatus. The sheet housing apparatus can be combined with the printer. The printer includes a pair of body-side feet disposed on both sides, in the width direction, of the printer. In a state in which the sheet housing apparatus is combined with the printer, the body-side feet and the housing-side feet are arranged not to overlap with each other in the width direction

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

Provided is an image forming apparatus including a positioning portion provided upstream of a transfer portion in a transport direction of a recording medium. The positioning portion positions the medium using a leading end of the medium. Additionally included is a detector that is disposed downstream of the positioning portion in the transport direction, and that detects passage of the leading end of the medium; and a controller that controls a transport speed in a period from when the leading end of the medium passes through the detector to when the leading end of the medium passes through a target position situated downstream of the detector in the transport direction, in accordance with a time since transport of the medium is started from the positioning portion until the leading end of the medium passes through the detector.

A sheet housing apparatus including a housing unit, which houses a sheet to be discharged from a discharging opening of a printer, and a pair of housing-side feet disposed on both sides, in a width direction, of the sheet housing apparatus. The sheet housing apparatus can be combined with the printer. The printer includes a pair of body-side feet disposed on both sides, in the width direction, of the printer. In a state in which the sheet housing apparatus is combined with the printer, the body-side feet and the housing-side feet are arranged not to overlap with each other in the width direction.

An image forming apparatus comprises a container, a supplier, a conveyor, a grammage detector, a sheet detector, an image former, and a processor. The processor sets a flag when the detected grammage exceeds a first grammage, measures a conveyance time of a sheet to the sheet detector, determines a conveyance delay of the sheet based on whether the conveyance time is greater than or equal to a first amount of time, counts a number of occurrences of the conveyance delay in a state where the detected grammage exceeds the first grammage, and prohibits supply of sheets from the container when the detected grammage exceeds a second grammage larger than the first grammage or the number of occurrences of the conveyance delay is greater than or equal to a threshold value.

An image forming apparatus includes an image bearing member, a transfer portion configured to transfer an image borne on the image bearing member to a sheet, a current detection portion configured to detect a current flowing through the transfer portion, a conveyance portion configured to convey the sheet to the transfer portion, a driving portion configured to drive the conveyance portion, and a controller configured to acquire an arrival timing at which a leading edge of a preceding sheet has arrived at the transfer portion based on a detection result of the current detection portion, and control the driving portion in response to the arrival timing in a state where a succeeding sheet that follows the preceding sheet is conveyed by the conveyance portion.

An image forming apparatus includes an image forming portion, a fixing portion, a temperature detecting portion, a measuring portion, a storing portion, and a controller. The controller is capable of setting a case that a start of feeding of a recording material is permitted after a lapse of a predetermined time need to measure a temperature rising rate of the fixing portion and a case that the start of feeding of the recording material is permitted, depending on a value relating to the temperature rising rate stored in the storing portion, at timing before the lapse of the predetermined time.