An image forming apparatus includes plural rotating members that are rotatable; an annular circulating member that is wound around the plural rotating members and circulates when the rotating members rotate; a retaining member attached to an attaching portion of the circulating member and that circulates together with the circulating member, the retaining member being configured to retain a recording medium in an area where the attaching portion comes into contact with one of the rotating members; an image forming section that forms an image on the recording medium at an image forming position defined on a circulation path along which the circulating member circulates; a delivering unit that delivers the recording medium to a retaining position where the recording medium is to be retained by the retaining member; a detector that detects rotation of the one rotating member; and a controller that controls delivery of the recording medium from the delivering unit to the retaining position, the delivery being controlled with reference to information detected by the detector.

An image forming apparatus includes a sheet stacking portion, an image forming portion, a detection portion configured to detect a position, in a sheet width direction, a storage configured to store position information of a sheet, and a controller. The controller is configured to cause the storage to store the position information based on a position of a sheet detected by the detection portion during execution of the job, and if sheet information of a sheet used in a previous job is matches sheet information of a sheet used in a current job, cause the image forming portion to start formation of an image to be formed on a first sheet, before a position of the first sheet is detected by the detection portion, based on the position information stored in the storage in the previous job.

A sheet feeding device includes a sheet feeding portion, a side end regulating portion, a feeding portion, first and second feeding roller pairs, an abutment member, an obliquely feeding roller pair, and first and second contact-and-separation mechanisms. Feeding of a long sheet is stopped after the sheet is fed to an upstream side of the second feeding roller pair by the feeding portion, and then is resumed in a state in which the first feeding roller pair is changed from a separated state to a feedable state and in a state in which the obliquely feeding roller pair is put in a separated state, and then the sheet is fed to the second feeding roller pair. A short sheet fed by the first feeding roller pair is obliquely fed by the obliquely feeding roller pair and then is fed to the second feeding roller pair.

An image forming apparatus includes an image bearer, an image forming device to form an image on the image bearer, a transfer device to transfer the image formed on the image bearer onto a sheet, a storage to store the sheet, a sheet feeder to convey the sheet one by one to the transfer device, and a slip amount prediction controller. The slip amount prediction controller calculates a predicted slip amount between the sheet feeder and the sheet before forming the image and, subsequently calculates an interval between images based on the predicted slip amount. The slip amount prediction controller controls the image forming device based on the calculated interval between images to form the image on the image bearer.

An image forming apparatus, including: a sheet cassette; an image former; a fixer; a discharge tray; a conveyor configured to convey a sheet along a conveyance passage; a return conveyor configured to convey the sheet from a branch position between the fixer and the discharge tray to a merge position between the sheet cassette and the image former along a return passage which is branched from the conveyance passage at the branch position, passes below the sheet cassette, and merges with the conveyance passage at the merge position; a switchback roller disposed between the branch position and the discharge tray in the conveyance passage and configured to convey the sheet to the discharge tray when it rotates forwardly and to the return passage when it rotates backwardly; and an intermediate conveyance roller disposed in the return passage at a height level intermediate between the fixer and the sheet cassette.

Disclosed is an image forming apparatus which includes: a feeding portion configured to feed a sheet; an image forming portion configured to form an image on the sheet; a conveying portion configured to stop the sheet fed by the feeding portion at a predetermined position and to convey the sheet to the image forming portion in accordance with a timing of forming the image by the image forming portion; a type discriminating portion configured to discriminate whether a type of the sheet to be fed belongs to a first sheet type group including plain paper or to a second sheet type group including coated paper; and a controlling portion configured to control feeding of the sheet, wherein the controlling portion is configured to change a sheet feeding start timing of the feeding portion in accordance with the type discriminated by the type discriminating portion.

An image forming device continuously forming an image according to a job in a conveying direction of along continuous paper includes: an image formation section forming the image according to the job on the continuous paper; an interval setting section setting a job interval of the image according to the job, which is continuously formed by the image formation section, on the basis of an operation from a user; an image forming process switching section switching two states of a state where the image formation section forms a color image and a state where the image formation section forms a monochromic image; and a switching determination section determining whether or not the two states are switched on the basis of a comparison result between the job interval set by the interval setting section and a paper conveying distance according to a switching time required for switching the two states.

The electro-photographic sheet of paper duplex printing machine includes a sheet supply section, a sheet positioning section which positions sheets and sends out sheets to a backup roller in an electro-photographic printing section, the electro-photographic printing section transfers an image which has been transferred onto the transfer roller onto the sheet, a chain delivery section, a delivery section and a sheet carrying section for turnover. The chain delivery section selectively transfers printed sheets, which has been transferred from the backup roller to the delivery section or sheet carrying section for turnover. The sheet carrying section for turnover supplies one side printed sheet to the sheet positioning section. The sheet fed from the sheet supply section and one side printed sheet fed from the sheet carrying section for turnover are alternately carried to the sheet positioning section and the toner image on the printed sheet is fixed by the fixing device.

An image forming apparatus includes a conveyance unit to convey a sheet toward an image forming position, a torque detection unit to detect a load torque applied to a motor driving the conveyance unit, and a control unit to perform a speed control for changing a rotational speed of the motor such that an interval at which a preceding sheet and a succeeding sheet pass through the image forming position approaches a target interval while the conveyance unit is conveying the succeeding sheet. The control unit executes an interval change processing for changing the target interval in the speed control based on a magnitude of a detected load torque when the conveyance unit is driven by the motor, the control unit controls power input to the motor by transmitting a command signal to a driving circuit of the motor, and the torque detection unit detects the command signal.

An image forming apparatus includes a feeder unit, a separating unit, a conveying unit disposed downstream of the separating unit in a sheet feeding direction, an image forming unit disposed downstream of the conveying unit in the sheet feeding direction, a drive unit, and a control unit. The feeder unit feeds a sheet. The separating unit separates sheets fed by the feeder unit one by one. The conveying unit conveys the sheet. The image forming unit forms, while the sheet is being conveyed, an image on the sheet. The drive unit drives the conveying unit. The control unit controls the drive unit. After the conveyed sheet reaches the image forming unit, the control unit reduces a conveyance speed of the sheet conveyed by the conveying unit.