Abstract: A method and apparatus for setting register on a multicolor printing machine (1) having color printing units (6, 6′, 6″, 6′″) assigned to various printing inks, at least one image cylinder (2, 2′, . . . ), image production equipment (3,3′, . . . ) for producing color separations (7, 7′, . . . ) on the at least one image cylinder (2, 2′, . . . ) and a carrier (4) for printing substrates (15). An assignment of the image production points (11, 11′, . . . ) on the at least one image cylinder (2, 2′, . . . ) is carried out in order to achieve coincidence of register between the color separations (7, 7′, . . . ) in the print, by both the production of the image starts (10) and the production of areas (10′, 10″, . . . , 10n) of the color separations (7, 7′, . . . ) set on the basis of the print and the evaluation of register marks (9, 9′, 9″, 9′″).

Abstract: Correcting register faults in a multicolor printing machine having a number of items of equipment for the digital production of color separations, wherein correction values are determined and assigned to angular positions of at least one image cylinder and, as a result, taken into account for the control of the production of the color separations on the image cylinder. Correction values are to be made available for the correction of register faults, which, with a fine graduation, make it possible to assign them to angular positions of machine elements in a repeatable way. This is achieved by determining circularity errors of machine elements which have an influence on the register, assigned to their angular positions and, from these, the correction values for the control of the production of the color separations on the at least one image cylinder being determined.

Abstract: A method and an apparatus for adjusting devices (1, 1′) for generating color separations (2, 2′) in a multicolor printing machine (3), changes in the dimensions (4, 4′, 5, 5′) of printing substrates (6) being taken into account by controlling the image generation. Changes in the dimensions (4, 4′, 5, 5′) of printing substrates (6) during or after printing are to be taken into account as early as during the image generation. The fiber orientation (7) of printing substrates (6) is registered and, on the basis of the fiber orientation (7) and values from experience (8, 8′, 10, 10′, 10″) of the behavior of printing substrates (6) depending on the fiber orientation (7), control being carried out before the start of printing.

Abstract: The invention relates to a device for detecting the location of an edge (2) of a transparent, anisotropic material (3, 3′) comprising at least one sensor (1) with a light source (4), two polarization filters (6,7) with transmission axes (8,9) meeting at a 90° angle as well as a light detector (10), whereby the light source (4) and one polarization filter (6) are located on one side of the edge (2) to be detected and the second polarization filter (7) and the light detector are located on the other side.

Abstract: A method for sensing a register discrepancy (r) in a multi-color printed item, the position of at least one register mark (1, 1′) that is associated with one color being sensed with respect to the position of at least one register mark (2, 2′) that is associated with at least one further color, and any density register discrepancy (r) using a measurement window being ascertained from discrepancies in the actual relative position (3) with respect to the reference relative position (4). The invention, furthermore, concerns an apparatus, a register control system, and register marks (1, 1′, 2, 2′).

Abstract: Setting registration, with detection of the entry of a printing substrate (2) into a printing machine (1) and calculation of the beginning of digital production of color separations (3, 3′, 3″, 3′″) to achieve an in-register position of the color separation prints (4, 4′, 4″, 4′″) on a printing substrate (2). This is achieved by the printing substrate (2) being detected before it enters the printing machine (1) and, following this detection, the relative positions of the color separations (3, 3′, 3″, 3′″) being calculated, and by precise detection of the leading edge (5) of the printing substrate (2) being performed as it enters the printing machine (1) and being made the basis for determining the starts of the production of the color separations (3, 3′, 3″, 3′″), their relative position having been precalculated.

Abstract: Determining and correcting registration errors, which are caused by the rotational speed of a print cylinder changing because of a sheet passing between the print cylinder and a sheet transport conveyor belt. At least one first registration mark is applied onto the conveyor belt prior to a sheet being transported thereby, and at least one second registration mark is applied onto the conveyor belt after the transported sheet. By the detection of the first registration mark and the second registration mark, a calculation of a timing number between the detection of the first registration mark and the second registration mark can be made. The calculated timing number is compared to a target value to determine any error due to change in angular velocity of the print cylinder due to engagement with the sheet.

Abstract: A process and printing machine for determining registration errors and correcting therefore. At least one first registration mark is applied onto a conveyor belt for transporting a sheet, and at least one second registration mark is applied onto the sheet adjacent to the first registration mark. The first registration mark and the second registration mark are detected, the distance between the first registration mark and the second registration mark is calculated, and the difference between the calculated distance and a distance without different speeds of the conveyor belt and the sheet (a target value) is calculated.

Abstract: A method and apparatus for setting registration in a multicolor printing machine (1) having a number of exposure devices (2, 2′, . . . ) for the digital production of color separations (3, 3′, . . . ), the actions of setting up and combining the color separations (3, 3′, . . . ) being controlled, in order to set registration, such that in-register prints are achieved, influencing variables (4, 4′, 4″) which are caused by the printed pages and have an influence on registration being taken into account in setting up and combining the color separations (3, 3′, . . . ) before the onset of a change in said influencing variables. Therefore, no interruption of the printing process between two different printed pages (33, 34) is necessary.

Abstract: A method and device for register mark setting of a printing press for multicolor printing. A calibration run is used for the calibration of register frames, and the correction data produced by the calibration of the frame is used to calibrate the register mark keeping of individual lines or areas of lines from the printing modules of the printing press, whereby the data of the register marks are detected to determine the correction data and are set in relationship to positions of an illustration drum and/or a separation drum.

Abstract: A method and apparatus for setting registration in a multicolor printing machine for the digital production of color separations, the actions of setting up and combining color separations being controlled when printing substrates of a different grade are fed in, in order to correct registration setting. In the event of a change in the printing substrate grade, the influence of this change on registration can be compensated for optimally before the printing substrate (16) is fed to the printing process. When the printing substrate grade is changed, the influence of all the properties of the printing substrate (16) that are relevant to registration is taken into account directly as the change is implemented, by correction values (4, 4′, . . . ) for the printing substrate (16) that are available before printing is carried out.

Abstract: Detection of crosstrack aberrations of registration marks in order to prevent color errors during multicolor printing. The detection of crosstrack aberrations of registration marks is with a single sensor which detects each triangle as a registration mark per color selection, whereby the triangles are each assigned a color of the multicolor printing. Sensor values are detected and formed from these differential values.

Abstract: A method and apparatus for setting registration in a multicolor printing machine (1), the print results on print substrates (4) being registered and used to control the production of color separations (3, 3′, . . . ) such that in-register prints are achieved. A change L? in the dimensions (7, 8, 7′, 8′) of the printing substrates (4) is determined by the print, in order to take this change into account such that coincidence can be achieved between a recto print and verso print. This is achieved by the changes in the dimensions (7, 8, 7′, 8′) of the recto print (6) being determined and being used to control the digital production of the color separations (3, 3′, . . . ) for the verso print (5) such that after being printed, it coincides with the recto print (6).

Abstract: A method and apparatus for setting register on a multicolor printing machine (1) having color printing units (6, 6′, 6″, 6″) allocated to various printing inks and having image cylinders (2, 2′), equipment (3, 3′) for producing images, in particular electrostatic latent images, on the image cylinders (2, 2′, . . . ), a carrier (4) for printing substrates (15) and image transfer points (5, 5′, 5″, 5′″) for the transfer of the color separations (7, 7′, . . . ) from the color printing units (6, 6′, 6″, 6′″) to the printing substrates (15), an allocation of the image productions (11, 11′) on the image cylinders (2, 2′, . . . ) to the printing substrates (15) being carried out in order to achieve coincidence of register of the color separations (7, 7′, . . . ) in the print. This is achieved by a time-independent allocation of the positions of the image productions (11, 11′, . . .

Abstract: Apparatus and a method for correcting registration faults based on changes in machine state (4, 4′, . . . ; 5, 5′, . . . ) in a multicolor printing machine (1) having a number of printing units (13, 13′, . . . ) with image cylinders (14, 14′, . . . ) and exposure devices (2, 2′, . . . ) for the digital production of color separations (3, 3′, . . . ) on the image cylinders (14, 14′, . . . ), the actions of setting up and combining the color separations (3, 3′, . . . ) being controlled such that in-register prints are achieved. Changes in machine state (4, 4′, . . . ; 5, 5′, . . . ) are registered and, on the basis of these changes in machine state (4, 4′, . . . ; 5, 5′, . . . ), the production of the color separations (3, 3′, . . . ) is changed such that a disturbance to registration accuracy of the print, threatened by a change in machine state (4, 4′, . . . ; 5, 5′, . . . ), is compensated for.

Abstract: Detecting the presence of an object, preferably a leaf sheet-shaped or sheet-shaped object on a transport path, especially for preparation and/or control of a processing of the object, preferably for printing the object in a printing machine, especially a digital printer, where the object is transported on the transport path past a sensor device, preferably a photoelectric barrier, for detection and registration of the front edge of the object in the transport direction. After detecting the front edge of the object and/or its entrance into the measurement area, it is checked at least once to determine whether the object continues to be present in the measurement area of the sensor device.

Abstract: The invention relates to a printing unit (1) for a printing machine, having an image cylinder (2), an image generating device (3) for setting an image on the peripheral surface (4) of the image cylinder (2), and an image transfer cylinder (5) which transfers the image from the image cylinder (2) to a printing substrate (6), the image transfer cylinder (5) having a resilient cover (7) which exhibits a deformation (10, 10′) in the force transmission areas (8, 9), and a transport belt (11) that carries the printing substrates (6) and is supported by a back-pressure cylinder (12) driving the image transfer cylinder (5) and the latter driving the image cylinder (2), by friction.

Abstract: A method and apparatus for setting registration in a multicolor printing machine having a number of exposure devices for the digital production of color separations, the actions of setting up and combining the color separations being controlled, in order to set the registration, in such a way that accurate registered prints are achieved. According to the invention, in the event of a change in the toner profile, the influence of the toner profile on the registration is taken into account, by available influencing variables directly as the change is implemented.

Abstract: A method and apparatus for setting register on a multicolor printing machine (1) having color printing units (6, 6′, 6″, 6′″) assigned to various printing inks, at least one image cylinder (2, 2′, . . . ), image production equipment (3, 3′, . . . ) for producing color separations (7, 7′, . . . ) on the at least one image cylinder (2, 2′, . . . ) and a carrier (4) for printing substrates (15). An assignment of the image production points (11, 11′, . . . ) on the at least one image cylinder (2, 2′, . . . ) is carried out in order to achieve coincidence of register between the color separations (7, 7′, . . . ) in the print, by both the production of the image starts (10) and the production of areas (10′, 10″, . . . , 10n) of the color separations (7, 7′, . . . ) set on the basis of the print and the evaluation of register marks (9, 9′, 9″, 9′″).

Abstract: The invention relates to a method and an apparatus for adjusting devices (1, 1′, . . . ) for generating color separations (2, 2′, . . . ) in a multicolor printing machine (3), changes in the dimensions (4, 4′, 5, 5′) of printing substrates (6) being taken into account by controlling the image generation.