Abstract: A method and control device for determining a register error, whereby at least one register mark is printed and at least one sensor records the register mark, whereby the sheet edge of the sheet is recorded by the sensor, and the register error is determined from the sensor data and the target data.

Abstract: Recognizing a print substrate in the vicinity of a sensor within a printing machine, whereby a change in the capacitance of the system formed by the sensor and a surface of an area in which a print substrate should be recognized, is recognized by the sensor. In this way, print substrates can already be identified on the basis of a dielectric constant that is different from that of air.

Abstract: The invention relates to a method and apparatus for minimizing the influence of register differences in multicolor printing, in particular in digital printing processes, register values (1) in the transport direction (2), which are different transversely with respect to this direction being set to a value between the extremes (3, 3?). The invention is intended to carry out a development such that the influence of register differences on the image quality can be minimized reliably and to a great extent. This is achieved by a number of individual values of the register values (1) being measured and an average value (4, 4?) being determined from these and brought into alignment with the average value (4, 4?) from at least one further color printing unit (5, 5?, 5?, 5??).

Abstract: Recognizing a print substrate in the vicinity of a sensor within a printing machine, whereby a change in the capacitance of the system formed by the sensor and a surface of an area in which a print substrate should be recognized, is recognized by the sensor. In this way, print substrates can already be identified on the basis of a dielectric constant that is different from that of air.

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. This type of device is to be configured in such a way that it can be used for detecting material (3,3′) with optical axes (14) in various directions without requiring assembly. This is achieved by at least one of the sensors (1) being configured and/or adjustable so that various angles (32) between the transmission axis of the first polarization filter (6) and the optical axis (14) of the transparent, anisotropic material (3,3′) are possible.

Abstract: The invention relates to a process and a device for alignment of sheet material (1) which is conveyed in one conveyor plane (9). The sheet material is conveyed on bodies (35) of revolution and aligned by means of triggerable alignment elements (25) in the conveyor direction (22) and perpendicular to the conveyor direction (22). The alignment elements (25) are assigned to an alignment unit (8). The alignment motion necessary for alignment of the sheet material in the conveyor direction (2) and perpendicular thereto takes placed by separate alignment elements (25) which can be triggered independently of one another during conveyance of the sheet material (1) with the process speed.

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: 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 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 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: 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: 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: The invention relates to a method for the alignment of sheet-like material (1). Its alignment occurs via rotation elements (25), wherein the sheet-like material (1) is rotated around its central axis in order to print on the front and backsides. During the rotation of the sheet-like material (1) around its central axis, the material's leading edge (23) remains in its aligned position. Into the conveyor surface (9) is incorporated a sensor pair (30), preferably in the form of CCD line sensors, with which the sheet-like material (1) is aligned on the same lateral edge (24) following the rotation, as is the case during the alignment procedure of the sheet-like material (1) before it is rotated around its center axis.

Abstract: The invention relates to a process and a device for alignment of sheet material (1) which is conveyed in one conveyor plane (9). The sheet material is conveyed on bodies (35) of revolution and aligned by means of triggerable alignment elements (25) in the conveyor direction (22) and perpendicular to the conveyor direction (22). The alignment elements (25) are assigned to an alignment unit (8). The alignment motion necessary for alignment of the sheet material in the conveyor direction (2) and perpendicular thereto takes placed by separate alignment elements (25) which can be triggered independently of one another during conveyance of the sheet material (1) with the process speed.

Abstract: The invention relates to a process for compensation of dimension changes on sheet material (1) which is first provided with a printed image (36) on the front (35) and which is then provided with a printed image (40) on its back (39). The dimensions (41, 42) of the sheet material (1) are determined before an image is printed on the front (35) and before an image is printed on the back (39), and before an image is printed on the back (39) of the sheet material (1) the latter is centered to its position when the image was printed on the front (35).

Abstract: The invention relates to 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.

Abstract: The invention relates to a method and apparatus for setting register in a multicolor printing machine (1) having a number of items of equipment (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 the register, in such a way that in-register prints are achieved, influencing variables (4, 4′, 4″) which are caused by the printed pages and have an influence on the register being taken into account in setting up and combining the color separations (3, 3′, . . . ) before the onset of a change in said influencing variables.

Abstract: The invention relates to a method and apparatus for the digital production of color separations (3, 3′, . . . ), the actions of setting up and combining the color separations (3, 3′, . . . ) being controlled when printing substrates (16) of a different grade are fed in, in order to correct the register setting.

Abstract: The invention relates to a method and apparatus for correcting register faults in a multicolor printing machine (1) having a number of items of equipment (2,2′, . . . ) for the digital production of color separations (3,3′, . . . ), correction values being determined and assigned to the angular positions (4,4′, . . . ) of at least one image cylinder (5,5′, . . . ) and, as a result, being taken into account for the control of the production of the color separations (3,3′, . . . ) on said image cylinder.