A sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.

A timing specifying device includes count processing circuitry to count an input reference clock; and timing control circuitry configured to set a parameter having an integer part and a fractional part in the count processing circuitry. The count processing circuitry counts the reference clock, outputs a timing signal indicating that a time corresponding to an integer value has passed, and counts a value corresponding to the fractional part at a timing at which the timing signal is output. The integer value is a value indicated by the integer part. The count processing circuitry stops counting of the reference clock when a value obtained by counting the value corresponding to the fractional part carries over from a fraction.

A sheet conveying device includes a support configured to move between a storage position and a full open position and including a pair of rollers, a plurality of contact bodies, and a switching unit. The switching unit switches the pair of rollers in response to contact of the plurality of contact target bodies included in the switching unit, with the plurality of contact bodies. The plurality of contact bodies includes a first contact body closer to the storage position than the plurality of contact target bodies with the support at the full open position and closer to the full open position with the support at the storage position, and a second contact body closer to the storage position than a part of the plurality of contact target bodies with the support at a halfway position and closer to the full open position with the support at the storage position.

An image forming apparatus according to the present disclosure includes a skew correction device and a cleaning device. The skew correction device includes first conveying rollers. The first conveying rollers are rotatable about a predetermined rotation fulcrum. The first conveying rollers are, before a sheet, which is skewed, enters a device body, rotated from an initial position, and, when the sheet enters the device body, rotated back to the initial position while nipping and conveying the sheet. The cleaning device includes a toner conveying member that conveys residual toner on an image-carrying member to a predetermined container. Both the first conveying rollers and the toner conveying member operate by consecutively receiving a rotational driving force from a common electric motor.

A sheet conveyance device includes a conveyance roller pair. A skew correction roller pair conveys the sheet after contacting two nip portions, and a sheet skew is corrected in a state in which the skew correction roller pair is being stopped. The sheet having a toner image is bent by a first conveyance guide such that a sheet first surface becomes an inside surface. The sheet is bent by the first and second conveyance guides to cause the sheet first surface to be the inside surface and a sheet second surface to be an outside surface. The skew correction roller pair includes two first rotary members of a first roller. A second roller and the two first rotary members form the two nip portions. The second roller and the first conveyance guide contact the sheet first surface. The first roller and the second conveyance guide contact the sheet second surface.

A paper feeding mechanism includes a feeding path, a driving motor, a bidirectional transmission mechanism, at least one feeding roller, a unidirectional transmission mechanism and at least one blocking roller. The driving motor is controllable to output a driving force towards a forward direction or a driving force towards a reverse direction. The bidirectional transmission mechanism is connected to the driving motor. The at least one feeding roller is mounted in the feeding path. The at least one feeding roller is connected to the bidirectional transmission mechanism. The unidirectional transmission mechanism is connected to the driving motor. The at least one blocking roller is mounted in the feeding path. The at least one blocking roller is disposed to a downstream of the at least one feeding roller. The at least one blocking roller is connected to the unidirectional transmission mechanism.

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.

An image forming apparatus includes a controller to move a sheet, in an image formation process on a first surface, to a standard position in a width direction and move the sheet, in an image formation process on a second surface, in the width direction based on a detected position in a case where a difference between the standard position and a first position in the width direction is equal to or smaller than a predetermined value. The controller moves the sheet, in the image formation process on the first surface, by the predetermined value in the width direction and moves the sheet, in the image formation process on the second surface, in the width direction based on detected positions in a case where the difference between the standard position and the first position in the width direction is larger than the predetermined value.

In an image-forming apparatus, when a sheet length of a first sheet is shorter than or equal to a predetermined length, a controller supplies power to an electromagnetic clutch to convey the first sheet and a second sheet so that a sheet gap of the second sheet is equivalent to a first gap. When the sheet length of the first sheet is longer than the predetermined length, the controller supplies power to the electromagnetic clutch to successively convey a first number of sheets so that the sheet gap of each of the first number of sheets is equivalent to the first gap. After the first number of sheets has been conveyed, the controller supplies power to the electromagnetic clutch to convey at least one sheet so that the sheet gap of each of the at least one sheet is equivalent to a second gap greater than the first gap.

A paper feeding mechanism includes a feeding path, a driving motor, a bidirectional transmission mechanism, at least one feeding roller, a unidirectional transmission mechanism and at least one blocking roller. The driving motor is controllable to output a driving force towards a forward direction or a driving force towards a reverse direction. The bidirectional transmission mechanism is connected to the driving motor. The at least one feeding roller is mounted in the feeding path. The at least one feeding roller is connected to the bidirectional transmission mechanism. The unidirectional transmission mechanism is connected to the driving motor. The at least one blocking roller is mounted in the feeding path. The at least one blocking roller is disposed to a downstream of the at least one feeding roller. The at least one blocking roller is connected to the unidirectional transmission mechanism.