公开(公告)号：US20230415491A1

公开(公告)日：2023-12-28

申请号：US18338724

申请日：2023-06-21

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD

IPC: B41J2/21

CPC classification number: B41J2/2139 ,  B41J2/2146 ,  B41J2/2142

Abstract: A method for aligning printing heads (12) of a printing device is provided, the printing heads (12) being two-dimensional printing heads (12) comprising a plurality of nozzles (30). In one method step, an ink drop is dispensed at a plurality of nozzles (30) of every printing head (12) simultaneously to print an image, preferably at all nozzles (30) of every printing head (12). In another step, the printed image is captured by a camera (20) whose resolution may be smaller than the print resolution. The position and/or orientation of each of the printing heads (12) is determined based on the image captured by the camera (20) and the deviation of the position and/or orientation of each printing head (12) from a target position and/or orientation is determined. The position and/or the orientation of the printing heads (12) is adjusted based on the determined deviation. Moreover, a printing device (10) is provided.

公开(公告)号：US20190154589A1

公开(公告)日：2019-05-23

申请号：US16099706

申请日：2017-05-17

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD ,  Francis PILLOUD

IPC: G01N21/89

CPC classification number: G01N21/8914 ,  G01N21/8901 ,  G01N2021/8905 ,  G01N2021/8908 ,  G01N2021/8917 ,  G01N2201/0626 ,  G01N2201/0634 ,  G01N2201/0636 ,  G01N2201/0637

Abstract: A quality control station (2) for a sheet element processing machine, having at least one camera (6) arranged for capturing images of sheet elements (4) transported through the quality control station (2), and further having an illumination unit (5) with at least one light emitter (16) and two reflectors (12, 14), the illumination unit (5) directing light onto a viewing area of the camera (6) such that the illumination intensity is constant despite changing media thickness. An illumination unit for such quality control station is disclosed.

公开(公告)号：US20190154578A1

公开(公告)日：2019-05-23

申请号：US16099042

申请日：2017-05-29

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD ,  Francis PILLOUD

IPC: G01N21/57 ,  G01N21/86

Abstract: A surface inspection system (10) for inspecting the surface of sheet elements (4) present in an inspection area (20). The system includes an image evaluation unit (18), a camera (12), a dark-field illuminator (14) and a bright-field illuminator (16). The image evaluation unit (18) subtracts a line image captured under bright-field illumination conditions from a line image captured under dark-field illumination conditions. A method of identifying highly reflective surface areas on a sheet element (4) being moved through a sheet element processing machine, wherein first a line image (I16) of the surface of the sheet element (4) in the viewing area (20) is captured under bright-field illumination conditions and a line image (I14) of the same surface of the sheet element (4) in the viewing area (20) is captured under dark-field illumination conditions, and then the two line images (I14, I16) are compared, in particular subtracted from each other, wherein the surface is identified as being reflective if the difference (Sn) between the two line images (I14, I16) is above a predefined threshold.

公开(公告)号：US20230415492A1

公开(公告)日：2023-12-28

申请号：US18338728

申请日：2023-06-21

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD

IPC: B41J2/215 ,  B41J2/14

CPC classification number: B41J2/215 ,  B41J2/14

Abstract: A method for fine adjustment of the position of ink drops printed by at least one printing head (12) of a printing device, the printing head (12) being a two-dimensional printing head (12) comprising a plurality of nozzles (30). In one method step, an ink drop is dispensed at a plurality of nozzles (30) of the at least one printing head (12) simultaneously to print an image, preferably at all nozzles (30) of the printing head (12). In another method step, the printed image is captured by a camera (20), wherein the camera (20) captures the pattern of dots printed by the printing head (12) and the captured pattern is compared to a pattern (36) of the nozzles (30) of the printing head (12). In a further method step, the dispensation of an ink drop from at least one nozzle (30) is modified in terms of timing with respect to the dispense of ink drops from the other nozzles (30) of the printing head (12) for the subsequent printing process if a deviation has been detected between the pattern (36) of dots printed by the printing head (12) and the nozzle pattern (36). Furthermore, a printing device is provided.

公开(公告)号：US20190178812A1

公开(公告)日：2019-06-13

申请号：US16301024

申请日：2017-05-29

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD ,  Francis PILLOUD

IPC: G01N21/89 ,  G01N21/88

Abstract: A surface inspection system (10) for inspecting the surface of sheet elements (2) present in an inspection area (5): The system includes an image evaluation unit (18), two light sources (12, 14) arranged adjacent each other on opposite sides of an illumination plane (O11) and oriented for illuminating the inspection area (5), and a camera (16) for capturing line images (I12, I14) of the inspection area (5) along a viewing plane (O16). The illumination plane (O11) and the viewing plane (O16) are arranged on opposite sides of a median plane (M) which is perpendicular to an inspection plane. The angle (α) between the illumination plane (O11) and the median plane (M) is the same as the angle (α) between the viewing plane (O16) and the median plane (M). Also, a method of inspecting the surface of sheet elements (4) by using the surface inspection system (10) as defined above, wherein a first of the two light sources (12, 14) directs light onto the sheet element (4) to be inspected, and the camera (16) captures a line image (I12; I14) of the inspection area (5), and then a second of the two light sources (14, 12) directs light onto the sheet element (4) to be inspected, and the camera (16) captures a line image (I14; I12) of the inspection area (5). Then an image evaluation unit (18) compares the captured line images (I14; I12) with each other, and in particular subtracts the images from each other.

公开(公告)号：US20190145760A1

公开(公告)日：2019-05-16

申请号：US16098576

申请日：2017-05-17

Applicant: BOBST MEX SA

Inventor： Matthieu RICHARD ,  Francis PILLOUD

IPC: G01B11/26 ,  G01N21/89 ,  G06K9/20 ,  G06K9/46 ,  G06T7/00 ,  G06K9/62

Abstract: An image capturing system (10), and a corresponding method, for determining the position of an embossed structure (30) on a sheet element (4) moved though a viewing area (18). It includes a camera (12) adapted for capturing a line image of the surface of the sheet element (4) in the viewing area (18), and an illumination unit (14) with a plurality of light sources (20, 21, . . . ) each adapted for illuminating the viewing area (18). The light sources (20, 21, . . . ) are arranged at different inclinations with respect to the viewing area (18). An image evaluation unit (16) determines an inclination-related parameter for the surface of the sheet element (4) in the viewing area (18) across the viewing area (18).