A roll sheet with a continuous sheet wound in a roll form is rotated in a forward direction to supply the sheet to a printing unit. A sensor whose output is changed in accordance with a distance between the sensor and the sheet is used. A rotation direction of the roll sheet is switched from an opposite direction to the forward direction on the basis of the output of the sensor during rotation of the roll sheet in the opposite direction.

An example jam removal structure can include a transporting roller transporting a print medium along a transporting path, an Inner-side guide, and first and second guides facing the inner-side guide to form the transporting path and located in an upstream side and a downstream side of the transporting roller based on a transport direction of the print medium to be rotatable to an open position opening the transporting path and a path formation position forming the transporting path. The example jam removal structure can include an operating lever connected to each of the first and second guides by first and second connecting members to switch the first and second guides to the open position or the path formation position and an elastic member applying an elastic force to the first and second guides in a direction rotating toward the path formation position.

An image forming apparatus is provided. The image forming apparatus includes a print engine to be used to perform an image forming job, a motor to start the print engine, a driving circuit to supply a power to the motor and to include a sensor to sense a size of current of the power supplied to the motor during an operation to perform the image forming job, and a processor to detect an occurrence of jam based on a size of current sensed by the sensor in a first time interval while the motor is driven and a size of current sensed by the sensor after a determined time from the first time interval.

An image forming apparatus includes a photoelectric sensor and a controller. The photoelectric sensor emits light to an object to be detected, receives the light reflected on the object and outputs an electric signal corresponding to a quantity of the reflected light. The object includes a facing surface area and a sheet on the facing surface area. The controller detects whether the sheet exists on the facing surface area in accordance with an output of the photoelectric sensor. The controller stores, as a threshold of the output of the photoelectric sensor, a first threshold for determining that the sheet does not exist on the facing surface area and a second threshold for determining that the sheet exists on the facing surface area, and determines that the facing surface area is contaminated when the output of the photoelectric sensor is within a range between the first threshold and the second threshold.

There is disclosed a device, method and program, wherein the method comprises detecting a power increase, during which power usage increases by at least a threshold amount over an expected power usage during movement of a printer carriage over a print medium along a scan axis. The increase method further comprises detecting a location of the printer carriage at a time of the detected power usage increase and determining, based on the detected location of the printer carriage, whether the print medium is damaged.

A sheet conveyor includes a conveyance belt configured to rotate to convey a sheet on which a liquid has been applied in a conveyance direction, and a guide configured to guide the sheet to the conveyance belt, a position of the guide being variable in the conveyance direction.

The invention which solves the relative speed problem between nips in a printing system is disclosed. The invention consists of a swing arm body that rotates about a pivot, an input drive gear, a forward swing arm gear, two reverse swing arm gears, a compound duplex drive gear, and a housing.

An image recording apparatus includes: a casing having an internal space; a conveying passage formed inside the casing; a first roller pair positioned in the conveying passage, having a driving roller and a driven roller, and configured to pinch a sheet and to convey the sheet in a conveying orientation; a platen positioned on a downstream side in the conveying orientation of the first roller pair, and having a supporting surface supporting the sheet; a recording part positioned above the platen and configured to record an image on the sheet supported by the platen; a second roller pair which is located on the downstream side in the conveying orientation of the supporting surface of the platen, and which is configured to pinch the sheet and to convey the sheet; and a moving mechanism configured to move the platen to a printing position and to a release position.

A printing apparatus, comprising a storage unit for storing a sheet, a printing unit for printing on the sheet conveyed by a first conveyance unit from the storage unit, a second conveyance unit, provided between the first conveyance unit and the storage unit, for conveying the sheet from the storage unit toward the first conveyance unit, a conveyance control unit for controlling driving of the first and the second convey units such that the sheet is bent between the first conveyance unit and the second conveyance unit, and a detection unit, provided between the first and the second conveyance units, for detecting bending of the sheet, wherein the conveyance control unit stops conveyance of the sheet by the first conveyance unit based on a detection result of the detection unit.

A printing system includes: a media feed chassis including a plurality of fixed roller shafts, each roller shaft having a rotatable roller for guiding print media through a media feed path; and inkjet modules mounted on the media feed chassis for printing on the print media. Each inkjet module includes: a support chassis seated on the media feed chassis; a maintenance chassis mounted on the support chassis; and a print bar chassis mounted on the maintenance chassis, the print bar chassis having inkjet printheads mounted thereon.