A sheet feeding apparatus for feeding a sheet includes a first lift tray configured to move up or down in a first lift range and to support a sheet; a sheet feeding unit configured to feed a sheet supported by the first lift tray; and a second lift tray configured to move up or down in a second lift range and to support a sheet in cooperation with the first lift tray. A lowest position in the second lift range is a position above a lowest position in the first lift range, and the second lift range is a range which is narrower than the first lift range.

An image forming apparatus includes: a sheet feeding tray that stares a sheet; a sheet thickness measurement device that measures a sheet thickness of the sheet fed from the sheet feeding tray; a hardware processor that: determines a type of the sheet of which the sheet thickness is measured, a sheet type associated with each of sheet thickness ranges, and the sheet thickness measured by the sheet thickness measurement device; and adjusts a first sheet thickness range by expanding the first sheet thickness range to at least one of an upper limit value side or a lower limit value side; and an image former that forms an image on the sheet fed from the sheet feeding tray under image forming conditions corresponding to the sheet type determined by the hardware processor.

An image forming apparatus includes: a sheet feeding tray that stores a sheet; a sheet thickness measurement device that measures a sheet thickness of the sheet fed from the sheet feeding tray; a hardware processor that: determines a type of the sheet of which the sheet thickness is measured, a sheet type associated with each of sheet thickness ranges, and the sheet thickness measured by the sheet thickness measurement device; and adjusts a first sheet thickness range by expanding the first sheet thickness range to at least one of an upper limit value side or a lower limit value side; and an image former that forms an image on the sheet fed from the sheet feeding tray under image forming conditions corresponding to the sheet type determined by the hardware processor.

A relay conveyance device includes a relay conveyance path arranged between an image forming apparatus and a post processing device to convey a sheet from the image forming apparatus to the post processing device, two reversing units reversing a surface side and a back-face side of the sheet, and a control device controlling conveyance of the sheet on the relay conveyance path. The relay conveyance path includes two reverse paths respectively passing through the two reversing units, a branch section branching into the two reverse paths at an upstream side, and a confluence section joining the two reverse paths. The control device controls the branch and confluence sections to convey the sheet while alternately switching the two reverse paths, measures an interval time between the sheets passing through the confluence section, and controls conveyance of the sheet in the two reverse paths so as to uniformize the interval time.

A fixing device includes a heating rotating member having a conductive layer and an exposed portion in which the conductive layer is partially exposed, and a roller including a metal core and an elastic portion, the roller forming a nip portion with the heating rotating member, the elastic portion being elastically deformed in a region where the nip portion is formed, wherein an annular conductive member provided in a longitudinal end portion of the metal core is in contact with the exposed portion of the heating rotating member while elastically deformed, and wherein in a state where the roller is not mounted to the fixing device, an outer diameter of the conductive member is smaller than an outer diameter of the elastic portion.

A paper feed apparatus comprises a paper feed section, a separation section, a rotating body and a control device. The paper feed section feeds an image receiving medium that is placed. The separation section is arranged at a downstream side of the paper feed section in a conveyance direction of the image receiving medium. If a plurality of the image receiving media fed from the paper feed section is overlapped, the separation section separates the plurality of the image receiving media that is overlapped. The rotating body is arranged at the upstream side of the separation section in the conveyance direction of the image receiving medium. The rotating body is capable of contacting with the placed image receiving medium. The rotating body is rotatable. The control device carries out control to rotate the rotating body at least before an operation of the paper feed section.

An image forming apparatus includes an image forming portion, a reversing portion configured to reverse the sheet received through a first feeding passage by feeding the sheet in a first direction and then in a second direction opposite to the first direction, a sheet feeding portion provided in a second feeding passage branching from the first feeding passage on a side upstream of the reversing portion with respect to the first direction, a first guiding surface forming the second feeding passage for guiding a first surface of the sheet fed by the feeding portion, and a second guiding surface for guiding a second surface, opposite from the first surface, of the sheet fed from the reversing portion in the second direction. The second guiding surface is movable with movement of the first guiding surface for opening the second feeding passage.

An image forming apparatus includes a stack portion on which a sheet is to be stacked, a regulating portion, a first detection device which includes a rotary variable resistor, a second detection, and a control unit. The regulating portion regulates a position of an edge of the stacked sheet. The first detection device outputs a detection signal based on the rotary variable resistor. The rotary variable resistor rotates in accordance with the sheet edge position regulated by the regulating portion. The second detection device detects presence or absence of the stacked sheet. The control unit calculates a calculated sheet width of the stacked sheet based on the output detection signal. The control unit sets the calculated sheet width after a first predetermined time has elapsed since the second detection device detects that the sheet is stacked on the stack portion as a detected sheet width of the stacked sheet.

A transfer device includes a transfer section that nips a recording medium between the transfer section and an image carrier, which carries an image on a surface thereof, with a variable pressure and that transfers the image on the image carrier to the recording medium; and a transport section that transports the recording medium while the recording medium passes through a transfer region between the image carrier and the transfer section. The transport section transports the recording medium with a first transport ability when the pressure is a first pressure and with a second transport ability that is lower than the first transport ability when the pressure is a second pressure that is higher than the first pressure.

Sheet feeding has been started after storing image data for one page of a document. A control method for a printing apparatus includes feeding a sheet from a sheet holding unit by a feeding unit, reading an image of a document by a reading unit, storing image data of the document read by the reading unit in a storing unit, and reading out, before image data for one page of the document is stored in the storing unit, the image data of the document from the storing unit and printing, by a printing unit, the image based on the read image data to the sheet fed from the sheet holding unit by the feeding unit, in which the feeding unit is able to start to feed the sheet from the sheet holding unit before the image data for the one page of the document is stored in the storing unit.