Measuring table for carrying out measuring tasks on a printed sheet printed in a printing machine

Abstract

The invention relates to a measuring table for carrying out measuring tasks on a printed sheet (11) printed in a printing machine, comprising a sheet placement surface (01) for placement of the printed sheet (11), wherein at least one suction device (12) generating negative pressure is arranged below the sheet placement surface (01), wherein said suction device (12) is designed in such a way that, when it is in the operating state, which is triggered by a control unit (09), it holds a printed sheet (11) lying on the sheet placement surface (01) in a force-locked manner by means of an air pressure that is lower than the barometric air pressure, wherein at least one surface portion (02) of the sheet placement surface (01) is made of a microporous block material having a natural porosity of at least 20%, wherein the block material is an inorganic non-metallic material and is air-permeable over its entire surface on account of its microporous structure, wherein at least one sensor (18) is arranged in an edge region (17) of the sheet placement surface (01), wherein the relevant sensor (18) is designed in such a way that it detects a printed sheet (11) lying on the sheet placement surface (01) and, when a printed sheet (11) lying on the sheet placement surface (01) is detected, sends a signal to the control unit (09).

Description

[0001] Description

[0002] Measuring table for carrying out measuring tasks on a sheet printed in a printing press

[0003] The invention relates to a measuring table for carrying out measuring tasks on a printed sheet printed in a printing press according to the preamble of claim 1.

[0004] From DE 102022 104 547 B3 a device for measuring a sheet is known, wherein the device for measuring has a measuring surface for placing a sheet, wherein the device for measuring has a suction device, wherein the suction device for fixing the sheet is arranged to apply and / or apply a negative pressure to the measuring surface via suction openings, wherein the device for measuring has a device for taut the sheet on the measuring surface, wherein at least the surface of the measuring surface has a porous ceramic and / or a porous aluminum.

[0005] DE 102007 030 571 A1 discloses a device for color measurement of printing materials, wherein this device for color measurement of printing materials has two measuring devices operating with different resolutions for detecting the surface of the printing material, wherein the different measuring devices are combined, for example, in a measuring head and wherein the device preferably has one or more light sources for illuminating the surface of the printing material.

[0006] From DE 102009 032 966 A1 a device for treating sheet-shaped substrates with light is known, in particular for the transmitted light inspection of sheet-shaped substrates made of paper, with a suction table which is equipped with a circulating suction belt which transports the sheet-shaped substrates and which forms a loop which is deflected downwards with respect to its transport plane parallel to the table and has a descending branch and an ascending branch adjacent to it, wherein a gap provided for the passage of light between the descending branch and the ascending branch is bridged by a stationary, at least partially light-permeable bridge piece, the surface of which is lowered with respect to the transport plane of the suction belt which is parallel to it, wherein the bridge piece for the transmitted light inspection e.g.a transparent plate with a smooth surface, preferably a glass plate, and wherein, for the transmitted light control, for example, a lighting device is arranged on one side of the transparent plate of the bridge piece and a camera is arranged on the other side.

[0007] The invention is based on the object of creating a measuring table for carrying out measuring tasks on a printed sheet printed in a printing press.

[0008] The object is achieved according to the invention by the features of claim 1. The dependent claims relate to advantageous embodiments and / or further developments of the solution found.

[0009] The advantages achievable with the invention consist in particular in that, for example, first register marks applied to the front side of a printed sheet can be measured in relation to second register marks applied to the back side of the same printed sheet and / or that, for example, a position of a watermark formed in a printed sheet can be compared in relation to a position of a printed image applied to the same printed sheet. Such measuring tasks have not previously been possible on a measuring table. The solution found also avoids transporting a printed sheet directly over a camera, which protects the camera from contamination caused by the transport of the printed sheet. Exemplary embodiments of the invention are illustrated in the drawings and are described in more detail below.

[0010] They show:

[0011] Fig. 1 is a plan view of a first embodiment of a measuring table for carrying out measuring tasks on a printed sheet;

[0012] Fig. 2 shows a camera arrangement on a second partial surface of a sheet support surface of the measuring table;

[0013] Fig. 3 a plan view of a second embodiment of the measuring table.

[0014] Fig. 1 shows a simplified plan view of a measuring table for performing measurement tasks on a printed sheet 11 (Fig. 2), e.g., made of paper, cardboard, or carton, printed in a printing press, particularly in an industrial printing process, and each in a format of, e.g., 1,000 mm x 700 mm or larger. This measuring table has a generally rectangular, preferably flat sheet support surface 01 for the full-surface placement of the printed sheet 11 to be measured. While the measurement tasks are being performed, the printed sheet 11 rests on the sheet support surface 01.

[0015] In a first embodiment of the measuring table, a first partial surface 02 of the sheet depositing surface 01 is made, for example, from a metallic material such as steel or aluminum and is designed to be permeable to air by structural measures. The air permeability of the first partial surface 02 is ensured in particular by this first partial surface 02 having, for example, an array of suction openings 08 made in the sheet depositing surface 01, which are designed, for example, in the form of drilled holes or openings. On an underside of this first partial surface 02, i.e. on a side of the first partial surface 02 facing away from the printed sheet 11 resting on the sheet depositing surface 01, at least one suction device 12 generating a vacuum is arranged in pneumatic connection to the suction openings 08.This suction device 12 is designed in such a way that, in the operating state of its activation triggered by a control unit 09 preferably belonging to the measuring table and a printed sheet 11 resting on the sheet depositing surface 01, it holds this printed sheet 11 force-fittingly by means of an air pressure which is reduced compared to the barometric air pressure and thus fixes it on the sheet depositing surface 01.

[0016] In the aforementioned first embodiment of the measuring table, its sheet depositing surface 01 has a second partial surface 03, wherein the second partial surface 03 is smaller than the first partial surface 02 and has, for example, a format on the order of 100 mm x 100 mm. The second partial surface 03 is either arranged within the first partial surface 02 and thus surrounded by the first partial surface 02, or the second partial surface 03 is arranged at least adjacent to the first partial surface 02. In the first embodiment of the measuring table, the second partial surface 03 is made of an air-impermeable, but translucent material. In this first embodiment of the measuring table, the second partial surface 03 of the sheet depositing surface 01 is, for example, designed as a transparent plate with a closed surface, i.e. completely translucent and thus also transparent to view, preferably as a glass plate.

[0017] In a second embodiment of the measuring table, the sheet support surface 01 or preferably at least a first partial surface 02 of this sheet support surface 01 is permeable to air and also translucent, wherein this first partial surface 02 of the sheet support surface 01 has a uniform and homogeneous air permeability in its contact area with the printed sheet 11, at least in its operating state with a printed sheet 11 resting thereon. The uniform and homogeneous air permeability of the first partial surface 02 of the sheet support surface 01 is achieved, for example, in that this air-permeable first partial surface 02 of the sheet support surface 01 is formed from a microporous block material with a natural porosity of at least 20%. The block material is, for example, an inorganic, non-metallic material and, due to its microporous structure, is preferably permeable to air over its entire surface.In this second design variant of the measuring table, the first partial surface 02 of the sheet support surface 01 is, for example, designed in a white color. A translucent material is only partially transparent, i.e., partially translucent, but not transparent or translucent.

[0018] It is advantageous to form the first partial surface 02 and / or the second partial surface 03 of the sheet support surface 01 with a solvent-resistant surface and / or with an ink-repellent surface. It is also advantageous to form the second partial surface 03 as a plate that can be replaced in the sheet support surface 01, preferably without tools. Furthermore, it is advantageous if a ruler is incorporated into the first partial surface 02 and / or the second partial surface 03 of the sheet support surface 01, e.g., by engraving, because then printed objects formed on a printed sheet 11 can be measured directly.

[0019] Advantageously, at least one light source illuminating the relevant partial surface 02; 03 is arranged on the underside of the first translucent partial surface 02 and / or on the underside of the second transparent partial surface 03 of the sheet depositing surface 01, i.e. on the side of the sheet depositing surface 01 opposite the printed sheet 11 lying thereon (Fig. 2).

[0020] The measuring table generally has a measuring device 04 which is movable bidirectionally in at least one direction above the sheet depositing surface 01, for example in the form of a measuring beam, the movability of the measuring device 04 being indicated in Figs. 1 and 3 by a double arrow. A first camera 06 is generally arranged on the upper side of the sheet depositing surface 01 at a distance from this sheet depositing surface 01, in particular in the movable measuring device 04 designed as a measuring beam, wherein a detection range of this first camera 06 can be brought into alignment with the air-impermeable second partial surface 03 of the sheet depositing surface 01, according to the example shown in Fig. 2. This first camera 06 is thus arranged such that its detection range faces a printed sheet 11 lying on the sheet depositing surface 01 or at least capable of being placed there.

[0021] In a preferred embodiment of the measuring table, a second camera 07 is arranged either on the underside of the air-permeable, translucent first partial surface 02 or on the air-impermeable, transparent second partial surface 03 of the sheet support surface 01. The second camera 07 is arranged in particular below the second partial surface 03 of the sheet support surface 01, which is designed as a transparent glass plate. By using the first camera 06 and the second camera 07 in combination, it is possible to simultaneously capture a front side and a back side of a printed sheet 11 to be measured. It is particularly advantageous to simultaneously capture register marks applied to the front side and back side of the same printed sheet 11 and / or to compare or check a position of a watermark formed in the printed sheet 11 in relation to a position of a printed image applied to the same printed sheet 11.The first camera 06 and / or the second camera 07 are designed, for example, as a line scan camera or as an area scan camera.

[0022] Fig. 2 shows, by way of example, in a partial section through the measuring table, an arrangement of the first camera 06, which can be moved by means of the measuring device 04, and the second camera 07, which is generally arranged stationary in the area of ​​the second partial area 03 below the sheet depositing surface 01 with respect to the measuring table, in an operating position in which the two cameras 06; 07 are positioned opposite one another in a vertical line and are each directed with their respective detection area onto a printed sheet 11 lying on the flat sheet depositing surface 01. Advantageously, the first camera 06 and the second camera 07 are each controlled by the control unit 09 belonging to the measuring table, i.e. the control unit 09 sends a signal, for example in a program-controlled manner, to the respective camera 06; 07, this signal being transmitted, for example,determines at what point in time the respective camera 06; 07 in its respective detection area captures an image of the printed sheet 11 lying on the sheet depositing surface 01 and then makes the image data corresponding to the respective image available to the control unit 09. The measuring device 04 is moved by a drive 13, for example an electric motor, in order to carry out its travel movement, whereby this drive 13 is in turn preferably also controlled by the control unit 09. In addition, it can be provided that a plurality of first lighting means 14, each of which particularly uniformly illuminates the detection area of ​​the first camera 06 and is also controlled by the control unit 09, are preferably arranged in the measuring device 04. Furthermore, the light source, which particularly uniformly illuminates the detection area of ​​the second camera 07, is advantageously arranged below the sheet depositing surface 01, for examplein the form of a plurality of second illuminants 16, which in turn are preferably controlled by the control unit 09. The illuminants 14; 16 are designed, for example, in the form of LEDs. The illuminants 14; 16 preferably emit white light as the light color.

[0023] In an edge region 17 (Fig. 1) directly adjacent to the second partial surface 03 of the sheet depositing surface 01 or surrounding the second partial surface 03, preferably a plurality of suction openings 08 are arranged, each in pneumatic connection to the suction device 12, in order to fix a printed sheet 11 lying on the sheet depositing surface 01 to this second partial surface 03 at least for the duration of an image created by at least one of the cameras 06; 07 of the relevant area of ​​this printed sheet 11 lying on the second partial surface 03.

[0024] Preferably, in the edge region 17 directly adjacent to the second partial area 03 of the sheet depositing surface 01 or surrounding the second partial area 03, at least one sensor 18 is arranged, for example, wherein the respective sensor 18 is designed such that it detects a printed sheet 11 resting on the sheet depositing surface 01. Preferably, in this edge region 17, several sensors 18 are arranged, for example, two sensors 18 diagonally opposite each other at corner points of the second partial area 03 (Fig. 1). The sensors 18, which act, for example, capacitively or optically, are designed such that they each emit a signal to the control unit 09 upon detection of a printed sheet 11 resting on the sheet depositing surface 01. The control unit 09 uses a signal received from at least one of the sensors 18, for example, to the effect that it activates the light source illuminating the detection area of ​​the second camera 07, i.e., the second illuminating means 16, only then, i.e.switches on when and as long as the respective sensor 18 detects the resting of a printed sheet 11 on the sheet support surface 01. The signal sent by at least one of the sensors 18 to the control unit 09 is thus used, for example, for a light control. The light control ensures that a person working at the measuring table is not dazzled. The light control thus serves, in particular, as eye protection.

[0025] The aforementioned sensors 18 can be used both in the described first embodiment of the measuring table and in its second embodiment. This is because the control unit 09 can, for example, also evaluate the signal received, e.g. digital, by at least one of the sensors 18 to activate the suction device 12 upon detection of a printed sheet 11 lying on the sheet depositing surface 01 in order to fix the printed sheet 11 lying on the sheet depositing surface 01 to the first partial surface 02 and / or to the second partial surface 03. After the relevant area of ​​this printed sheet 11 lying, e.g. on the second partial surface 03, has been imaged by at least one of the cameras 06; 07, the control unit 09 can deactivate the suction device 12 again, in particular under program control, i.e. switch off its suction acting through the suction openings 08 introduced into the sheet depositing surface 01, so that, for example,an operator can remove the respective printed sheet 11, which has been released from its fixation, from the sheet depositing surface 01 and, for example, place another printed sheet 11 on top.

[0026] Fig. 3 shows an example of a top view of the second embodiment of the measuring table. In this second embodiment of the measuring table, the first partial surface 02 of the sheet support surface 01 is permeable to air and translucent. The first partial surface 02 of the sheet support surface 01 preferably consists of a microporous block material with a natural porosity of at least 20%. This first partial surface 02 of the sheet support surface 01 has a plurality of illuminants 16 on its underside and can also have, for example, one or more zones 19 of reduced layer thickness in order to generate a brightness on the surface of this first partial surface 02 that differs from the remaining surface of the first partial surface 02, with an unchanged illuminance of the illuminants 16 arranged below the sheet support surface 01. These zones 19 of different, usuallyGreater brightness can be used to show the operator a position for positioning a printed sheet 11 or a ruler for measuring the relevant printed sheet 11. As already mentioned, this second embodiment of the measuring table also generally has a measuring device 04 that can be moved bidirectionally in at least one direction above the sheet depositing surface 01, e.g. in the form of a measuring bar.

[0027] From what has been described so far, it follows, for example:a measuring table for carrying out measuring tasks on a printed sheet 11 printed in a printing press, comprising a sheet depositing surface 01 for placing the printed sheet 11, wherein the sheet depositing surface 01 has a first partial surface 02 designed as an array of suction openings 08 introduced into the sheet depositing surface 01, wherein on a side of the first partial surface 02 facing away from the printed sheet 11 resting on the sheet depositing surface 01, at least one suction device 12 generating a negative pressure is arranged in pneumatic connection to the suction openings 08, wherein this suction device 12 is designed such that, in the operating state of its activation triggered by a control unit 09, it holds a printed sheet 11 resting on the sheet depositing surface 01 in a force-fitting manner by means of an air pressure which is reduced compared to the barometric air pressure, wherein the sheet depositing surface 01 has a second partial surface 03 designed to be smaller than the first partial surface 02.The second partial area 03 is arranged either within the first partial area 02 or at least adjacent to the first partial area 02, the second partial area 03 having a closed surface on its side facing a printed sheet 11 resting on the sheet depositing surface 01 and being made of a transparent material, a camera 07 being arranged on the side of the second partial area 03 facing away from the resting printed sheet 11, the camera 07 being directed with its detection area through the second partial area 03 onto the side of the printed sheet 11 resting on the sheet depositing surface 01 that is in contact with the second partial area 03.In addition, a measuring device 04 which can be moved bidirectionally in at least one direction above the sheet depositing surface 01 is preferably provided, wherein a camera 06 is arranged in the movable measuring device 04, wherein a detection range of this camera 06 arranged in the measuring device 04 is directed onto a side of the printed sheet 11 lying on the sheet depositing surface 01 which side faces the measuring device 04, wherein the camera 06 arranged in the measuring device 04 above the sheet depositing surface 01 is designed as a first camera 06 and the camera 07 arranged below the second partial surface 03 is designed as a second camera 07, each sending image data to the control unit 09.At least one sensor 18 is preferably arranged in an edge region 17 directly adjacent to the second partial surface 03 of the sheet depositing surface 01 or surrounding this second partial surface 03, wherein the sensor 18 in question is designed such that it detects a printed sheet 11 resting on the sheet depositing surface 01 and, upon detection of a printed sheet 11 resting on the sheet depositing surface 01 and / or at least on the second partial surface 03, sends a signal to the control unit 09. The control unit 09 is preferably designed such that it switches on the suction device 12 and / or the second lighting means 16 only when and as long as the sensor 18 in question detects the resting of a printed sheet 11 on the sheet depositing surface 01 and / or on the second partial surface 03.The control unit 09 is further designed such that it switches off the suction device 12 after an image of the printed sheet 11 lying on the second partial surface 03 has been taken by the first camera 06 and / or the second camera 07, and / or that it switches off the first lighting means 14 after an image of the printed sheet 11 lying on the sheet depositing surface 01 or on the second partial surface 03 has been taken by the first camera 06, and / or that it switches off the second lighting means 16 after an image of the printed sheet 11 lying on the second partial surface 03 has been taken by the second camera 07.

[0028] From what has been described so far, there also arises, for example, a measuring table for carrying out measuring tasks on a printed sheet 11 printed in a printing press, comprising a sheet support surface 01 for placing the printed sheet 11, wherein at least one suction device 12 generating a negative pressure is arranged below the sheet support surface 01, wherein this suction device 12 is designed such that, in the operating state of its activation triggered by a control unit 09, it holds a printed sheet 11 resting on the sheet support surface 01 in a force-fitting manner by means of an air pressure that is reduced compared to the barometric air pressure. At least one partial surface 02 of the sheet support surface 01 is formed from a microporous block material with a natural porosity of at least 20%, wherein the block material is an inorganic, non-metallic material and, due to its microporous structure, is permeable to air over its entire surface.In the preferred embodiment, the block material is a translucent material. Preferably, a measuring device 04 is provided that can be moved bidirectionally in at least one direction above the sheet depositing surface 01. A camera 06 is arranged in the movable measuring device 04, with a detection range of this camera 06 arranged in the measuring device 04 being directed towards a side of the printed sheet 11 resting on the sheet depositing surface 01 that faces the measuring device 04. First illuminating means 14 that illuminate at least the detection range of the camera 06 arranged in the measuring device 04 are arranged above the sheet depositing surface 01, and / or second illuminating means 16 that illuminate the block material are arranged below the sheet depositing surface 01. These illuminating means 14; 16 are each controlled by the control unit 09.Advantageously, the block material of the sheet depositing surface 01 has one or more zones 19 of reduced layer thickness, wherein the respective zone 19 has a brightness on the surface of the block material that differs from the remaining surface of this block material when the illuminance of the second illuminant 16 arranged below the sheet depositing surface 01 remains unchanged. The block material can also have a position for positioning the printed sheet 11 to be placed on the sheet depositing surface 01 or a ruler for measuring the respective printed sheet 11 by means of an engraving introduced into it. For example, at least one sensor 18 is arranged in an edge region 17 of the sheet depositing surface 01, wherein the respective sensor 18 is designed such that it detects a printed sheet 11 resting on the sheet depositing surface 01 and, upon detection of a printed sheet 11 resting on the sheet depositing surface 01, sends a signal to the control unit 09.In addition, the control unit 09 is advantageously designed such that it switches on the suction device 12 and / or the second lighting means 16 only when and as long as the relevant sensor 18 detects the resting of a printed sheet 11 on the sheet depositing surface 01. The control unit 09 can also be designed such that it switches off the suction device 12 and / or the first lighting means 14 and / or the second lighting means 16 after the camera 06 has captured an image of the printed sheet 11 resting on the sheet depositing surface 01.

[0029] Furthermore, a method for carrying out measuring tasks on a printed sheet 11 printed in a printing press results, wherein the printed sheet 11 in question is placed on a sheet support surface 01 of a measuring table and fixed there by suction air, wherein a detection area of ​​a first camera 06 arranged above the sheet support surface 01 of the measuring table, which is bidirectionally movable in at least one direction, is directed onto a side of the printed sheet 11 lying on the sheet support surface 01, said side facing this measuring device 04.At least one partial surface 03 of the sheet depositing surface 01 is made of a transparent material, wherein a second camera 07, which is arranged stationary below this partial surface 03 with respect to the measuring table, is directed with its detection range towards the transparent partial surface 03 of the sheet depositing surface 01, wherein the first camera 06 and the second camera 07 each send image data captured from the printed sheet 11 resting on the sheet depositing surface 01 in their respective detection range to a control unit 09 of the measuring table. In a preferred embodiment, the first camera 06 and the second camera 07 capture their image data captured from the printed sheet 11 resting on the sheet depositing surface 01 simultaneously in their respective detection range.The first camera 06 and the second camera 07 detect, in their respective detection ranges, register marks applied to a front side and a back side of a same printed sheet 11 resting on the sheet support surface 01. The first camera 06 and the second camera 07 can also detect, in their respective detection ranges, a position of a watermark formed in the printed sheet 11 in relation to a position of a print image applied to the same printed sheet 11. The measuring device 04 is driven, for example, by a drive 13 controlled by the control unit 09, wherein the measuring device 04, controlled by the control unit 09, is moved by means of its drive 13 into an operating position in which the detection range of the first camera 06 and the detection range of the second camera 07 face each other in a vertical line 21.

[0030] Advantageously, a change in position of the measuring device 04 above the sheet depositing surface 01 driven by the drive 13 and a capture of image data from both the first camera 06 and the second camera 07 are each carried out under program control by the control unit 09. Furthermore, at least one sensor 18 is arranged, for example, in an edge region 17 of the sheet depositing surface 01, wherein the respective sensor 18 detects a printed sheet 11 resting on the sheet depositing surface 01 and, upon detection of a printed sheet 11 resting on the sheet depositing surface 01, sends a signal to the control unit 09.In this case, the control unit 09 preferably switches on the suction device 12 only when and as long as the relevant sensor 18 detects the resting of a printed sheet 11 on the sheet depositing surface 01, and the control unit 09 switches off the suction device 12 after an image of the printed sheet 11 resting on the sheet depositing surface 01 has been taken by at least one of the two cameras 06; 07.

[0031] List of reference symbols

[0032] 01 Sheet storage area

[0033] 02 first sub-area

[0034] 03 second sub-area

[0035] 04 Measuring device

[0036] 05 -

[0037] 06 first camera

[0038] 07 second camera

[0039] 08 Suction opening

[0040] 09 Control unit

[0041] 10 -

[0042] 11 printing sheets

[0043] 12 Suction device

[0044] 13 Drive

[0045] 14 first light bulbs

[0046] 15 -

[0047] 16 second bulbs

[0048] 17 Marginal area

[0049] 18 Sensor

[0050] 19 Zone

[0051] 20 -

[0052] 21 vertical line

Claims

Claims 1. A measuring table for carrying out measuring tasks on a printed sheet (11) printed in a printing press, comprising a sheet support surface (01) for placing the printed sheet (11), wherein at least one suction device (12) generating a negative pressure is arranged below the sheet support surface (01), wherein this suction device (12) is designed such that, in the operating state of its activation triggered by a control unit (09), it holds a printed sheet (11) resting on the sheet support surface (01) in a force-fitting manner by means of an air pressure reduced compared to the barometric air pressure, wherein at least one partial surface (02) of the sheet support surface (01) is formed from a microporous block material, wherein the block material is an inorganic, non-metallic material and is permeable to air over its entire surface due to its microporous structure, characterized in thatthat the block material is formed with a natural porosity of at least 20%, wherein at least one sensor (18) is arranged in an edge region (17) of the sheet depositing surface (01), wherein the sensor in question (18) is designed such that it detects a printed sheet (11) lying on the sheet depositing surface (01) and, upon detection of a printed sheet (11) lying on the sheet depositing surface (01), sends a signal to the control unit (09).

2. Measuring table according to claim 1, characterized in that the block material is a translucent material.

3. Measuring table according to claim 1 or 2, characterized in that a measuring device (04) is provided which is movable bidirectionally in at least one direction above the sheet depositing surface (01), wherein a camera (06) is arranged in the movable measuring device (04), wherein a detection range of this camera (06) arranged in the measuring device (04) is directed to one of the measuring devices (04) facing side of the printed sheet (11) resting on the sheet depositing surface (01).

4. Measuring table according to claim 2 or 3, characterized in that above the sheet depositing surface (01) first illuminating means (14) are arranged which illuminate at least the detection area of the camera (06) arranged in the measuring device (04) and / or that below the sheet depositing surface (01) second illuminating means (16) are arranged which illuminate the block material, wherein these illuminating means (14; 16) are each controlled by the control unit (09).

5. Measuring table according to claim 4, characterized in that the block material of the sheet support surface (01) has one or more zones (19) of reduced layer thickness, wherein the zone in question (19) has a brightness on the surface of the block material which differs from the remaining surface of this block material when the illuminance of the second illuminating means (16) arranged below the sheet support surface (01) remains unchanged.

6. Measuring table according to claim 1 or 2 or 3 or 4 or 5, characterized in that the block material has, by means of an engraving introduced into it, a position for the placement of the printed sheet (11) to be placed on the sheet support surface (01) or a ruler for measuring the printed sheet (11) in question.

7. Measuring table according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that the control unit (09) is designed such that it switches on the suction device (12) and / or the second lighting means (16) only when and as long as the relevant sensor (18) detects the resting of a printed sheet (11) on the sheet depositing surface (01).

8. Measuring table according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7, characterized characterized in that the control unit (09) is designed such that it switches off the suction device (12) and / or the first lighting means (14) and / or the second lighting means (16) in each case after an image of the printed sheet (11) lying on the sheet depositing surface (01) has been taken by the camera (06).

9. Measuring table according to claim 3 or 4 or 5 or 6 or 7 or 8, characterized in that the measuring device (04) is driven by a drive (13), wherein the drive (13) is controlled by the control unit (09).

Images