A conveyance device includes: a conveyance mechanism configured to unwind and convey a web from a web roll; a brake configured to brake rotation of the web roll; a controller configured to perform control of gradually reducing a torque of the brake and then turning off the brake in an operation of turning off the brake in a state where conveyance of the web by the conveyance mechanism is stopped and the brake is on with a tension applied to the web between the web roll and the conveyance mechanism.

A medium conveying apparatus includes a conveyance roller to convey a medium, a DC motor to drive the conveyance roller, a processor to rotate the DC motor, an encoder to output a first pulse signal whose cycle varies according to a rotation speed of the DC motor, and an imaging device to acquire an image acquired by imaging a conveyed medium in response to a pulse of a second pulse signal whose cycle is constant. The processor detects a number of pulses of the second pulse signal included in a predetermined cycle of the first pulse signal, and discards images acquired by the imaging device in the same number of pulses as difference between the detected number of pulses and a reference number, in a next cycle of the predetermined cycle of the first pulse signal, when the detected number of pulses exceeds the reference number.

A sheet conveyor includes: a holder that detachably holds a sheet roll; a conveyance roller that conveys, by rotation, a sheet pulled out from the sheet roll; a first motor that rotates the conveyance roller; a second motor that rotates the sheet roll along with the conveyance of the sheet; a tension estimator that estimates tension of the sheet conveyed by the rotation of the conveyance roller; a measuring device that measures a physical quantity related to rotary motion of the conveyance roller; and a controller. The controller estimates acceleration torque of the second motor required for rotating the sheet roll depending on acceleration of the conveyance roller, based on rotation acceleration of the conveyance roller specified by the physical quantity measured by the measuring device, and calculates a feedforward control input for the second motor based on the acceleration torque estimated.

Example implementations relate to determining a correction factor that converts a measured sensor distance to a calibrated sensor distance. The measured sensor distance may be based on an amount of substrate advancement through a web printing press between detecting a mark on the substrate at a first sensor and detecting the mark at a second sensor. The calibrated sensor distance may be the separation between the first sensor and the second sensor.

A system for determining an amount of stretch film unwound from a stretch film dispensing apparatus. The stretch film dispensing apparatus includes a roller, from which the stretch film can be unwound, at least one supply roll sensor positioned relative to the roller to sense a distance from the at least one supply roll sensor to an outside face of a supply roll on a core on the roller, and a controller. The controller is configured to determine the amount of stretch film unwound based on the one or more signals provided by the at least one supply roll sensor.

An upstream drive roller transports an elongate medium. An upstream tension sensor detects tension of the medium. A downstream drive roller transports the medium. A downstream tension sensor detects tension of the medium in a position between the upstream and downstream drive rollers. A control unit controls transportation of the medium by operating the upstream drive roller based on a first difference which is a difference between a first detection value and a target value, operating the downstream drive roller based on a second difference which is a difference between a second detection value and a target value, and when a specific condition is satisfied, further operating the downstream driver roller with an adjustment value, which is based on the first difference, added to the second difference.

In a printing apparatus, the ends of print media fed continuously can be prevented from colliding with each other. The printing apparatus includes a printing unit configured to perform a print operation, a detecting unit configured to detect a conveyance abnormality, a conveying unit configured to convey a preceding print medium and a succeeding print medium, a conveying path having a first area including a curved portion at which a conveying direction of the print medium is curved and a second area upstream of the first area, and an opening unit capable of opening the first area of the conveying path. In a case in which a leading edge of the succeeding print medium is located in the second area at the time of the detecting unit detecting conveyance abnormality of the preceding print medium, the conveying unit conveys the succeeding print medium so that the leading edge of the succeeding print medium reaches the first area.

It is disclosed a substrate compactness detection method for a printer wherein the printer comprises a roller to receive a substrate roll and a media advance mechanism to receive a substrate from the substrate roll, the method comprising: determining a substrate thickness; advancing the substrate for a length; measuring an angular displacement of the roller caused by the advancing of the substrate; determining the substrate roll radius by using the length and the angular displacement; and calculating a compactness parameter in view of the substrate roll radius and the substrate thickness.

An unwinding assembly comprising first and second unwinding and handling units comprising respective robots having respective wrists movable under the control of at least one electronic control unit, wherein each of said unwinding and handling units comprises a respective unwinding device mounted on the wrist of the respective robot. The present invention also relates to an unwinding and handling unit capable of handling the reel carried by it with high freedom of movement, while maintaining small dimensions.

A tape feeder includes a magnet that rotates as one with a sprocket driven by a motor, two magnetic field detecting elements that detect signals in accordance with a magnetic field from the magnet and that are arranged at positions opposite the rotation region of the magnet, and a rotation angle detecting circuit that detects the rotation angle of the magnet and the rotation angle of the sprocket by processing output signals of the magnetic field detecting elements. A control section of the tape feeder reads the detection information of the rotation angle detecting circuit from immediately after the motor is started, recognizes the rotation angle of the sprocket, detects the position of tooth of the sprocket of the tooth engaged with a feeding hole of component supply tape based on the recognition results of the rotation angle of the sprocket for each pitch feeding operation of the sprocket, and corrects the pitch feeding amount of the motor by a pitch error correcting amount set for the tooth.