There is provided a liquid jetting apparatus including a conveyor, a liquid jet head, a carriage, a carriage moving device, and a controller. The controller carries out printing by repeating a scan-printing operation and a conveyance operation, and carries out a process of determining a jet-timing such that the jet-timing and a predetermined reference timing may deviate oppositely from each other between a print area on the upstream side and a print area on the downstream side along a scanning direction for the carriage to move in the scan-printing operation with respect to a predetermined reference position in the scanning direction, based on a value of a correction parameter. The correction parameter is set to the same value for nozzles included in an identical one of nozzle groups and to different values for the corresponding nozzles included in different ones of the nozzle groups.

A conveyance unit conveys a sheet on a conveyance path. A first detection unit detects a sheet on the conveyance path. A determination unit determines an adjustment amount for adjusting an interval from a trailing end of a preceding sheet to a leading end of a succeeding sheet according to a difference between a measurement interval and a target interval. A correction unit corrects the adjustment amount according to a difference between a measurement value of a length of the preceding sheet in a conveyance direction and a reference value of the length of the preceding sheet in the conveyance direction. A control unit controls the conveyance unit such that a conveyance speed of the conveyance unit is accelerated or decelerated during a period of time that corresponds to the adjustment amount corrected by the correction unit.

A controller calculates a first time period T1 and a second time period T2. The first time period T1 is defined as a time period required for conveying the end portion of the sheet, which is conveyed in a first conveyance direction E, disposed on the upstream side in the first conveyance direction E up to a reversal position A3. The second time period T2 is defined as a time period required for conveying an end portion of the reversed sheet disposed on an upstream side in a second conveyance direction R from the reversal position A3 to a branching point A1.

An image forming apparatus includes at least one conveyance roller pair, an image forming unit, at least one brushless motor, a motor drive control unit, a delay amount detector, and an image formation control unit. The image formation control unit controls the motor drive control unit to convey the sheets at a predetermined timing toward the image forming unit. The image formation control unit, during a continuous image formation in which a plurality of sheets are continuously conveyed by the conveyance roller pair with a predetermined sheet spacing and images are sequentially formed on the respective sheets, controls the motor drive control unit to sequentially perform an on and off control of the brushless motor corresponding to the respective sheets, and adjusts the sheet spacing and a rise time in the on control of the brushless motor corresponding to the rotation delay amount detected by the delay amount detector.

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 information processing device performs processing of specifying a positional relationship between a first printing section and a second printing section based on image capturing data of a test image that is printed on a printing medium by the first printing section and the second printing section in each of which a plurality of printing elements are arranged. The test image includes a plurality of first lines which are printed by the first printing section so as to have printing positions different from each other in a line arrangement direction on the printing medium and a plurality of second lines which are printed by the second printing section so as to have printing positions different from each other in the line arrangement direction. The information processing device contains a printing coordinate acquisition section, a printing position acquisition section, and a positional shift amount calculation section.

There is provided a liquid jetting apparatus including a conveyor, a liquid jet head, a carriage, a carriage moving device, and a controller. The controller carries out printing by repeating a scan-printing operation and a conveyance operation, and carries out a process of determining a jet-timing such that the jet-timing and a predetermined reference timing may deviate oppositely from each other between a print area on the upstream side and a print area on the downstream side along a scanning direction for the carriage to move in the scan-printing operation with respect to a predetermined reference position in the scanning direction, based on a value of a correction parameter. The correction parameter is set to the same value for nozzles included in an identical one of nozzle groups and to different values for the corresponding nozzles included in different ones of the nozzle groups.

An image forming apparatus includes an image forming unit, a fixing unit, and a control unit. The image forming unit forms a toner image on a recording material. The fixing unit heats and fix the toner image formed on the recording material to the recording material in a fixing nip portion. The fixing unit includes a heater and a nip portion forming member that forms the fixing nip portion to pinch and convey the recording material. The control unit control the power to be supplied to the heater so as to change a temperature gradient at time of warm-up of the fixing unit to a target temperature in accordance with time from start of power supply to the heater until entry of the recording material into the fixing nip portion.

An image forming apparatus includes an image bearer; a transfer rotator to contact the image bearer to form a transfer nip therebetween; a bias application device to apply, to the transfer rotator, a transfer bias, a cleaning bias to remove toner adhering to the transfer rotator, and a non-image area bias smaller in absolute value than the cleaning bias; and a controller to control the bias application device and set a sheet feeding interval according to a predetermined condition. When the sheet feeding interval exceeds a predetermined threshold, the controller causes the bias application device to apply, to the transfer rotator, the non-image area bias for an application time Z and the cleaning bias for a time XZ within the sheet feeding interval when X represents the sheet feeding interval, and the application time Z is increased as the sheet feeding interval is increased.

A sheet detection unit includes a photo-interrupter, a shutter holder, and shutter members held to be movable relative to the shutter holder. The shutter members include a sheet rear end detection portion capable of switching an optical axis between a light-interrupted state and a light-transmitted state and each are supported to be movable to an abutment position where the shutter member causes an abutment surface to protrude, and also movable to a retracted position where the shutter member is retracted from a sheet conveyance path. Based on a detection signal output from the photo-interrupter by the sheet front end detection portion and the sheet rear end detection portion moving relative to the optical axis, a control unit determines the presence or absence of a sheet.