A screen printer comprising: a board positioning device configured to convey and hold a board to a work position in the screen printer; a mask holding device configured to hold a mask above the work position; a squeegee device configured to spread a cream solder on a mask on the board; a correction device configured to correct a relative position between the board of the board positioning device and the mask of the mask holding device; a control device configured to acquire inspection data of a print state from a print inspection device provided inside or outside the screen printer and perform correction control on the correction device by a correction value corrected according to a deviation amount of printing based on the inspection data; and an input device configured to include an instruction input section that senses an inspection instruction operation of an operator and transmit, to the control device, an inspection data acquisition signal for acquiring the inspection data of the print state from the print inspection device based on an instruction operation of the operator to the instruction input section.

A sheet-fed printing unit has a first impression cylinder and a second impression cylinder, which are arranged directly and interactingly in contact and which each have an axis of rotation. An axial plane contains the axes of rotation. A reference plane is a plane which contains an axis of rotation of a cylinder of this type and has a horizontal surface normal. These two cylinders are arranged such that an intersection angle between the axial plane and the reference plane is a maximum of 15°. A transport path is provided for a transportation of sheets, which transport path has a region for the respective impression cylinder in which there is contact between sheets and a casing surface. This region of the transport path for the respective impression cylinder extends over an angular range of at least 270°. A sheet-fed printing machine has a sheet-fed printing unit of this type.

In some examples, a screen printing unit includes a screen printing forme cylinder, an impression cylinder, and at least one further rotational transport body. A fixing element of the impression cylinder includes inner and outer contact surfaces for clamping sheets. The inner contact surface has a base radius as a distance from an axis of rotation of the impression cylinder. A cylinder barrel of the impression cylinder has a supporting surface for sheets that includes an impression portion having a constant barrel radius, which extends over at least 170° about the axis of rotation of the impression cylinder and the barrel radius is larger than the base radius. A fixing element of the further rotational transport body includes an inner and an outer contact surface for clamping sheets. The inner contact surface includes the base radius as a distance from an axis of rotation of the further rotational transport body.

In some examples, a screen printing unit includes a screen printing forme cylinder, an impression cylinder, and at least one further rotational transport body. A fixing element of the impression cylinder includes inner and outer contact surfaces for clamping sheets. The inner contact surface has a base radius as a distance from an axis of rotation of the impression cylinder. A cylinder barrel of the impression cylinder has a supporting surface for sheets that includes an impression portion having a constant barrel radius, which extends over at least 170° about the axis of rotation of the impression cylinder and the barrel radius is larger than the base radius. A fixing element of the further rotational transport body includes an inner and an outer contact surface for clamping sheets. The inner contact surface includes the base radius as a distance from an axis of rotation of the further rotational transport body.

A screen-printing apparatus for repeatedly marking an indicium at regularly spaced intervals or predefined discrete intervals on a surface or medium. The screen-printing apparatus includes a wheel mounted to a housing. A screen frame can be mounted to a housing that can interchangeably receive a screen having void(s) of a shape that corresponds to the indicia to be printed. The screen-printing apparatus also has an ink supplying unit that sprays ink over the top surface of the screen. A solenoid operably coupled to the ink supplying unit for triggering the ink supplying unit. The solenoid and the wheel are operably coupled to a control unit, the control unit can receive readings from the wheel about the distance covered by the wheel on the surface and based on the readings can trigger the solenoid at predefined intervals.

An apparatus calibrates the optical sensor to calibrate the distance measured by the sensor with the expected distance using a calibration surface at the expected distance.

A printing parameter acquisition device includes an acquisition section and an output section. The acquisition section acquires a printing condition for specifying a member to be used when solder is printed on a board. The output section outputs a printing parameter which is associated with a printing condition corresponding to a printing condition acquired by the acquisition section and of which a reliability is a predetermined level or more, from a database that stores the printing condition, a printing parameter used for controlling driving of a printer, and the reliability of the printing parameter including inspection information on a print state of the solder inspected by a printing inspector in association with each other.

A method is disclosed, which method is or at least can be carried out in a flexographic printing press for the purpose of determining a position of mutual contact between a printing roller and at least one counter roller. An average position of mutual contact between the printing roller and the counter roller is calculated, based on every position of mutual contact between the printing roller and the counter roller that is determined for a specific angular position of the printing roller and is used to execute a printing process carried out by the flexographic printing press.

A method is disclosed, which method is or at least can be carried out in a flexographic printing press for the purpose of determining a position of mutual contact between a printing roller and at least one counter roller. An average position of mutual contact between the printing roller and the counter roller is calculated, based on every position of mutual contact between the printing roller and the counter roller that is determined for a specific angular position of the printing roller and is used to execute a printing process carried out by the flexographic printing press.

The invention relates to a method for checking a printing cylinder for defects in an engraved cylinder surface of the printing cylinder, comprising the steps: capturing a first and at least one further digital image of a cylinder surface of a printing cylinder by means of an optical capture unit, wherein the cylinder surface is cleaned before capturing the at least one further image, comparing the digital images each with a digital engraving master of the printing cylinder, the comparing comprising: determining deviations between each of the digital images and the digital engraving master, and checking the determined deviations for matching deviations between the digital images,
wherein a pseudo defects is concluded if no matching deviations between the digital images have been detected when comparing, and wherein an engraving defect on the printing cylinder is concluded in the case of matching deviations. Furthermore, a corresponding arrangement is described.