An image forming apparatus employing an electrophotographic image forming unit and an inkjet image forming unit, thereby being capable of printing an image on each of a front surface and the back surface of a recording medium.

The printer includes an image forming unit which forms an image on a sheet and a media sensor which detects a characteristic of the sheet. If the characteristics of the sheet do not support automatic double-sided printing, the printer forms an image on the first side of the sheet and discharges the sheet to an FD sheet discharge portion or an FU sheet discharge portion. After discharging the sheet, the printer instructs a user to place the discharged sheet on a cassette or a manual feed tray. If the sheet having the image formed on the first side is placed on the cassette or the manual feed tray, the printer forms an image on a second side of the sheet.

An image forming apparatus includes a controller that receives a print job, which includes the sheet type and print settings of simplex printing or duplex printing. A sheet stacked on a feeding unit is discharged to a discharge portion with an upper surface of the sheet facing different directions in duplex printing and in simplex printing in a first mode, and the sheet stacked on the feeding unit is discharged to the discharge portion with the upper surface of the sheet facing the same direction in the duplex printing and in the simplex printing in a second mode.

A sheet conveying apparatus includes a paper re-feeding path, a switching member, a reversing roller, a paper discharge roller, a motor, and a revolution control mechanism. The switching member can be switched between a first position and a second position. The reversing roller can reverse a revolving direction thereof between a first revolving direction and a second revolving direction. The paper discharge roller revolves in a third revolving direction for conveying the sheet in a third conveying direction. The motor reverses the revolving direction of the reversing roller and switches the position of switching member by reversing the revolving direction thereof. The revolution control mechanism revolves the paper discharge roller in the third revolving direction with the revolution of the motor, regardless of the reversing of the revolving direction of the motor.

A sheet conveyance apparatus includes a first conveyance portion configured to convey a sheet, a second conveyance portion configured to convey the sheet, the second conveyance portion including an abutment portion configured to form a loop on the sheet by being abutted against a leading edge of a sheet conveyed by the first conveyance portion, a curved guide portion, which is curved, configured to guide the sheet conveyed by the first conveyance portion to the second conveyance portion, and a rotary member arranged downstream of the first conveyance portion and upstream of the second conveyance portion in a sheet conveyance direction, and configured to be driven to rotate by a surface of the sheet that is guided by the curved guide portion, the surface sliding against the curved guide portion.

A recording-medium transport device includes: a driving roller that rotates in a driving manner; a discharge-side driven roller that is externally in contact with the driving roller and guides a recording medium to a discharge path located downstream of the driving roller in cooperation with the driving roller; a duplex-path-side driven roller that is externally in contact with the driving roller and guides, in cooperation with the driving roller, the recording medium from the discharge path to a duplex printing path; and a projection projecting further toward the discharge path than an outer circumferential surface of the driving roller.

A first conveyance member reverses a sheet received from a first conveyance path. Second through fourth conveyance members are disposed on a second conveyance path and convey a sheet from the first conveyance member toward the first conveyance path. A restriction portion is capable of restricting driving force of a first driving source from acting on a sheet through the second conveyance member. A controller executes a first operation and a second operation. In the first operation, a second driving source stops driving the third and fourth conveyance members while a first sheet is being nipped at the fourth conveyance member, and a second sheet is conveyed to be abutted with the third conveyance member. In the second operation, the second driving source starts driving the third and fourth conveyance members while the restriction portion restricts driving force of the first driving source from acting on the second sheet.

An image forming apparatus includes a transfer portion configured to transfer a toner image to a sheet, a fixing portion configured to fix the toner image, a reverse conveyance portion configured to perform a reverse conveyance operation in which the sheet is conveyed to a first direction and thereafter conveyed to a second direction that is opposite to the first direction, a reverse guide configured to guide the sheet in reverse conveyance operation, a conveyance guide pair configured to form a conveyance path through which the sheet subjected to the reverse conveyance operation passes, and to guide the sheet toward the transfer portion, an air blowing portion configured to blow air toward the conveyance path, and a ventilation portion through which air blowing from the air blowing portion toward the reverse guide passes, the air having passed through the ventilation portion flowing along the reverse guide.

An image forming unit forms an image on a sheet. A reverse unit pulls in the sheet from a main conveyance path and reverses a conveyance direction of the sheet to feed the sheet to a sub-conveyance path. A control unit causes a conveyance unit to convey a first sheet that is waiting to the main conveyance path after a trailing end of a second sheet that has been fed from a feeding unit and follows the first sheet has passed through a merging point, and moves a trailing end of the first sheet downstream of a branch point before the second sheet reaches the branch point.

An image forming apparatus is configured such that in a case where images are to be formed on a first surface of a preceding sheet, on a first surface of a succeeding sheet fed to the first conveyance path succeeding to the preceding sheet and on a second surface of the preceding sheet, a first conveyance member is stopped without reversing the preceding sheet to a second conveyance path in a case where the image has been formed on the first surface of the preceding sheet and permission of preparing the image to be formed on the first surface of the succeeding sheet is not issued yet, and the first conveyance member restarts conveyance of the preceding sheet to the second conveyance path based on timing when an image forming unit starts preparing the image to be formed on the first surface of the succeeding sheet.