JP2577791B2 - Plate area ratio measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for measuring a pattern area ratio of a printing plate. For example, the present invention relates to a highly accurate pattern area ratio for each ink / key zone of a printing plate of an offset rotary press. Available to measure to.

[Conventional technology]

For example, the opening of each ink key of an offset rotary press,
That is, the ink supply amount for each ink / key zone is determined by the picture area ratio (the ratio of the area of the image area to the total area of the ink / key zone) for each ink / key zone. Therefore, when setting the opening degree of each ink key, it is necessary to obtain a picture area ratio for each ink key zone of the printing plate.

As a conventional apparatus for obtaining this pattern area ratio, as shown in FIG. 6, two optical deflectors 62 and 63 and a photoelectric deflector 62 are located near one point on a normal line set in the center of a printing plate 61 to be measured. Converter 6
4 is placed close to. The two light deflectors 62 and 63 are controlled by the light deflector controller 65, and the light beam of the laser oscillator 66 is emitted in the two-dimensional direction of the plate 61, that is, in the X-axis direction (plate width direction) and in the Y direction. Scan in the axial direction (printing plate length direction). On the other hand, there is known a device that receives reflected light from the printing plate 61 by a photoelectric converter 64, inputs the amount of received light to an arithmetic unit 67, and calculates a picture area ratio of the printing plate 61.

Other conventional devices include a plurality of photoelectric conversion elements arranged in a line as shown in FIGS.
A measuring head 74 having a pair of linear light sources 72 and 73 such as fluorescent lamps arranged on both sides of the plate 71 is moved in parallel along the upper surface of the plate 75, or the plate 75 is moved in parallel. On the other hand, there is also an apparatus that receives reflected light from the printing plate 75 by the photoelectric conversion element 71, inputs the amount of received light to an arithmetic unit (not shown), and calculates a picture area ratio of the printing plate 75.

[Problems to be solved by the invention]

In these conventional devices, the former has a problem in terms of maintenance. That is, the picture area ratio measuring device 2
Each of the light deflection devices is a high-precision device that always performs high-speed scanning during measurement, and if the operation is not good, the measurement accuracy is reduced. Therefore, the optical deflecting device requires advanced mechanical system adjustment every predetermined operation time, and there is a problem in the operation rate.

In addition, since the measurement accuracy of this pattern area ratio measuring device is apt to be reduced due to the influence of external light, it is necessary to block the light by enclosing the optical system of the measuring device and the printing plate with a completely large casing.

By the way, the printing plate by offset printing is usually 0.5m ×
The size is about 0.5m to 1.2m × 1.4m. Since such a large printing plate and an optical system for measuring the pattern area ratio of the printing plate are surrounded by a housing, the size of the pattern area ratio measuring apparatus by this method tends to be large.

Further, with respect to the latter device, uniform illumination and light receiving characteristics are required over the entire surface in order to accurately measure the pattern area ratio of a printing plate having a large area. However, in the case of the picture area ratio measuring device according to this method, it is difficult to stably and uniformly maintain the light emission amount for a long time because the fluorescent lamp is used as the linear light source. In addition, since it is difficult to keep the sensitivity of the plurality of photoelectric conversion elements arranged in a line at the same level, uniform light receiving characteristics cannot be expected. As a result, the picture area ratio measuring device has a problem in accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-precision plate area ratio measuring apparatus having a good operating rate.

[Means for solving the problem]

Therefore, in the present invention, a light source that irradiates a beam of light without using a light deflecting device, a photoelectric converter that receives reflected light from a printing plate, and a transmitter that reads the scale of a scale member are provided at predetermined positions of a measuring head. When the measuring head moves in the direction along the scale member near the surface of the printing plate in the direction of the X-axis, that is, in the X-axis direction, the transmitter of the measuring head reads the scale of the scale member to generate a pulse, so that a precise pulse is generated. Sampling timing can be obtained. In other words, the measurement head scans the printing plate while collecting data one after another by sampling the measured value every time the pulse is generated, thereby enabling highly accurate measurement. The moving means for moving the measuring head in the X-axis direction is used in combination with a feed roller for feeding the printing plate in a direction orthogonal to the X-axis, that is, in the Y-axis direction, so that the entire printing plate can be measured. The goal is to achieve the goal.

Specifically, a feed roller for transporting the printing plate in one direction while holding the front and back surfaces of the printing plate, and a scale of the reference physical quantity arranged parallel to the feed roller and at a constant pitch are formed. A scale member, a transmitter that reads a scale of the scale member and outputs a pulse, a light source that irradiates a light beam onto the plate surface, and a photoelectric converter that receives reflected light from the plate and converts it into an electric signal. A measuring head, a scanning unit for reciprocating the measuring head along the scale member, and sampling a signal from the photoelectric converter every time a pulse output from the transmitter is received, to design a picture of the printing plate. And an arithmetic processing unit for calculating the area ratio.

[Action]

When the printing plate is set on the plate area ratio measuring apparatus of the present invention, the printing plate is fed in the Y-axis direction by a feed roller and stopped at a predetermined position. When the printing plate stops, the measuring head starts scanning from one end to the other end in the X-axis direction of the printing plate by the scanning means. At this time, the transmitter of the measuring head detects the physical quantity of the scale member, and transmits a pulse every time the measuring head moves by the same distance as the width of the light beam. Each time this pulse is input to the arithmetic processing unit, the arithmetic processing unit receives a signal from the photoelectric converter, samples a reading of this signal, and stores it as data. When the measuring head reaches the other end of the printing plate, the scanning means stops the measuring head in the measuring head stop range outside the other end of the printing plate. When the measuring head stops, the feed roller moves the printing plate to Y.
It is sent axially the same distance as the length of the light beam.

Hereinafter, when the scanning of the measuring head in the X-axis direction and the feeding of the printing roller in the Y-axis direction are repeated several times, and the surface of the printing plate is completely measured, the arithmetic processing unit converts the data received from the photoelectric converter. The picture area ratio of the printing plate is calculated based on the above.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 show a front view and a vertical cross-sectional side view, respectively, of a part of the picture area ratio measuring device of the present embodiment. The apparatus of the present embodiment has a frame 1 made of a steel plate capable of supporting each apparatus as a main part of a frame, and a plate 3 (see FIG. 2) for sending a printing plate 3 (see FIG. 2) between side surfaces 2 of the frame 1. A pair of front and rear feed rollers 4 are provided via bearings 5. The roller 4 is composed of, for example, a rubber roller or the like, and is driven by a servomotor 6 installed at the left central portion of the frame 1 via an interlocking unit 7 such as a timing belt.

On the side surface 2, a movable frame supporting a pair of rubber rollers or the like, which is opposed to the above-mentioned pair of front and rear feed rollers 4, holds the plate 3 together with the feed rollers 4 and also acts as a feed roller. 9 is provided so as to be slidable in the vertical direction. A driving device 10 for driving the movable frame 9 is installed near the movable frame 9. The drive device 10 has a general structure, for example, a fluid pressure cylinder, a combination of a motor and a rack and pinion,
It is composed of a combination of a motor and a ball screw shaft.

A plate carrying-in port 32 and a plate guiding side surface 33A and a plate front guiding surface 33B are provided on the left side in FIG. 2 of the pair of front and rear rollers 4 and 8 on the right side in the feeding direction of the plate 3, respectively. Feed roller
A right rear guide surface 33D is provided on the right side of the fourth and the eighth. An intermediate portion guide surface 33C is provided at an intermediate portion between the front and rear guide surfaces 33B and 33D and an intermediate portion between the pair of rollers 4 and 8.

In the vicinity of the intermediate guide surface, stoppers 19 are supported in a row by supporting means (not shown). This stopper 19
The rod-shaped limb 19A can be moved up and down by a drive cylinder 19B, and can be protruded and retracted between the feed rollers 4.

When the stopper 19 projects, the printing plate 3 guided by the plate guide side surface 33A and sent on the roller 4 comes into contact with the stopper 19 so that the printing plate 3 is accurately set at a predetermined position. It has become.

At the end of the measurement, the printing plate 3 is disengaged from the feed rollers 4, 8 and slides down on the rear guide surface 33D by gravity to be able to be discharged.

It is necessary to calibrate the pattern area ratio depending on the type of the printing plate 3, and a calibration mark 34 is provided on the top surface of the printing plate in the feed direction so that the calibration can be performed first at the start of measurement.

Further, a bracket 14 is provided between both side surfaces 2,
The measurement head 11 can slide forward and backward along the X-axis direction via a guide roller 26 on the rail 12 provided on the bracket 14. Both ends of a timing belt 15 are coupled to the measuring head 11 on the left and right sides in FIG. 1 of the measuring head 11, respectively, and the timing belt 15 is endless with the measuring head 11 interposed therebetween. This timing belt 15
Is wound around a timing pulley 17 attached to the drive shaft of the servomotor 16 and a timing pulley 18 attached to the right side surface 2 of the frame 1. Here, the timing belt 15 and the timing pulleys 17 and 18 constitute a scanning unit.

Behind the pair of front and rear pressing rollers 8, a contact rail 20 is stretched between both side surfaces 2 of the frame 1 in parallel with the bracket 14 as shown in FIG. One contact rail 20 is supported by each surface of a support member 21 having a square cross section. A contact brush 22 provided at the rear of the measuring head 11 is in electrical contact with each contact rail 20.

The contact rail 20 and the contact brush 22 are formed of four poles by sharing one pole of the communication line and one pole of the power line out of a total of five poles of three poles of the communication system and two poles of the power supply system.

At the right edge of the bracket 14 in FIG. 2, as shown in FIG. 3, a slit 13 is provided by punching a metal plate at a pitch width dimension W, and a scale member 27 in a lattice shape is provided. . The scale member 27 has portions at both ends where the slits 13 are not cut. A range where the slit 13 is not cut is a measurement head stop range R in which the measurement head 11 is stopped. In addition, the width of the middle portion of the scale member 27, that is, the portion having the slits 13 is the width S which is the maximum width of the printing plate 3 or more.

A photo interrupter 28, which is a transmitter including a light emitting diode and a light receiving element (not shown), is provided on the rear upper surface of the measuring head 11 with the scale member 27 interposed therebetween.

A photoelectric converter 29 and a light source 30 for irradiating the printing plate 3 with a light beam having a width W and a length L are provided on the left edge of the measuring head 11.
Are provided so as to be slidable up and down. The box 31 is moved up and down by a drive mechanism (not shown) including a rack and pinion, a motor, and the like, and the drive mechanism can be linked with the up and down movement of the movable frame 9. At this time, the width dimension W of the light beam is
The pitch width W of the 27 slits 13 is equal to the pitch width W.

The pulse from the photo-interrupter 28 and the signal of the measurement data from the photoelectric converter 29 are input to the measurement head unit measurement control device 23 installed at the rear of the measurement head 11, and the measurement head unit measurement control device 23 The data is filed so that the pattern area ratio can be calculated by processing the measurement data.

In FIG. 2, below the servo motor 16,
A main measurement control device 24 and a power supply device 25 are provided.
The main measurement control device 24 and the measurement head unit measurement control device
23 is electrically connected through the contact rail 20 and the contact brush 22.

Here, the measurement head unit measurement control device 23 and the main measurement control device 24 constitute an arithmetic processing device.

This arithmetic processing unit has two
CPUs are separately arranged, and measurement control can be performed by a measurement control program.

The measurement head unit measurement control device 23 is configured by connecting a ROM 37, a RAM 38, a communication interface I / O device 39, and an I / O device 41 for an AD converter 40 to a measurement head CPU 35 via a bus line 36. And a stabilizing power supply 42 for supplying power to the device of the measuring head 11, the photo interrupter 28, the light source 30, and the like.

The photoelectric converter 29 is connected to the AD converter 40 of the measurement head unit control device 23, so that the measurement head 11
When moving in the axial direction, the measuring head CPU 35 measures the reflection amount of the light beam of the light source 30 from the printing plate 3 and can store it in the RAM 38.

The main measurement control device 24 connects the ROM 45, the RAM 46, the input / output device 47, the communication interface I / O device 48, and the I / O device 50 for the operation device control device 49 to the main CPU 43 via the bus line 44. Be composed. Here, the input / output device 47
It is a man-machine interface such as a CRT display device and keyboard.

The contact rail 20 and the contact brush 22 shown in FIG. 2 are connected to the measurement head section measurement control device 23 and the main measurement control device 24, respectively, as shown in FIG. Thus, the measurement head CPU 35 of the measurement head unit measurement control device 23 and the main CPU 43 of the main measurement control device 24 communicate with each other via the communication interface I.
Communication is possible via the / O devices 39 and 48, and the stabilized power supply 42 can receive power supply from the power supply device 25. The stabilized power supply 42 uses an AC IC regulator, a switching power supply, or the like. Contact rail
Even if the primary resistance of the stabilized power supply 42 fluctuates due to a change in the contact resistance between the contact brush 20 and the contact brush 22 when the measuring head 11 slides, the stabilized power supply 42 has a stable secondary voltage. Electricity can be supplied to each part.

Next, the operation of this embodiment will be described below with reference to FIG.

First, the printing plate 3 to be measured is set in the measuring device of the present embodiment. At this time, in order to set the printing plate 3 at the measurement reference position of the measuring device, the right end of the printing plate 3 in the feeding direction is directed toward the printing plate inlet 32 along the right plate guide side surface 33A, and the printing plate inlet Insert more. Thus, the X-axis reference of the printing plate 3 and the measuring apparatus of the present embodiment is adjusted. Next, when the printing plate 3 is inserted as it is, the leading end of the printing plate 3 comes into contact with the stopper 19 which has been raised in advance. By setting the printing plate 3 at this position, the Y-axis reference alignment between the printing plate 3 and the measuring apparatus of the present embodiment is performed.

Before and after the setting of the printing plate 3, parameters and the like different depending on the type of the printing plate 3 and the printing press are manually input to the main measurement control device 24 by the input / output device 47. This parameter differs depending on the dimensions of the printing plate 3 and the printing machine using the printing plate. For example, by inputting the width and length of the printing plate 3, the number of samplings N _MAX and Y of the measurement values in the X-axis direction are input. It calculates the number of frame feeds I _MAX in the Y-axis direction of the plate 3 in the axial direction,
It is used when calculating the picture area ratio for each ink key of a printing press.

After the operation for starting these measurements is completed, the input / output device 47 of the main measurement control device 24 is operated to activate the measurement control program.

This measurement control program, as shown in FIG.
In order for the CPUs to share functions, two separate programs are separately executed, and when they need to communicate with each other, necessary information is transmitted and received by communication to perform measurement control. In the figure, S101 to S113 show each step of the main CPU measurement control program, and S202 to 211 show each step of the measurement head CPU measurement control program.

The started measurement control program executes the printing plate 3 in S101.
The initial value of the measurement counter I for counting the number of times of frame feeding is set, and calibration is performed at the same time. At this time, the feed roller 8
Then, the servo motors 6 and 16 are controlled so that the measuring head 11 is positioned directly above the calibration mark 34 of the printing plate 3 by lowering the stopper 19.

Next, in S102, a measurement command is transmitted to the measurement head CPU35. In S103, the printing plate 3 is moved to a predetermined position, and the measuring head is
11 makes it possible to scan the leading end portion of the printing plate 3 in the feed direction so that the first measured value can be sampled. Next, the measuring head 11 is moved in the X-axis direction and starts measurement.

The measurement head CPU 35 waiting for the measurement command from the main CPU 43 in S201 and S202 sets the initial value of the measurement counter N for counting the number of samplings in S203 in response to the reception of the command, and then in S204 to S209. Perform measurement control as repeated, thereby measuring head unit measurement control device 23,
Repeat the sampling of the measured value.

That is, when the measuring head 11 moves in the X-axis direction, the photo interrupter 28 moves while sandwiching the scale member 27, and generates a pulse at each pitch of the slit 13. S204, S
Every time this pulse is received at 205, the measurement head CPU 35
Performs the sampling while holding the amount of light received by the photoelectric converter 29 (S206), and writes it in a predetermined position of a file set in the RAM 38 (S207). This operation is repeated whenever the measuring head 11 is within the width of the printing plate 3 (S208). Upon this repetition, the measurement counter N is incremented by 1 and counted up (S209). When the measurement head 11 reaches the right end of FIG. 3 of the printing plate 3, the measurement counter N is equal to N _MAX, the light beam width W of the pitch width W and the light source 30 of the slit 13 of the scale member 27 Since the dimensions are the same, the measurement head CPU 35 finishes sampling the entire width direction of the printing plate 3 at the count I = 1 of the measurement counter I. At this point, all of these measured values are stored in the RAM 38.

After completing the I-th measurement count, the measurement head CPU 35 transmits the end of the I-th measurement count to the main CPU 43 in S210 and S211 and transfers the measurement data of the I-th measurement count to a file. Return again, main CPU43
Wait for the command.

On the other hand, after the main CPU 43 starts moving the measuring head,
In steps 104 to S106, the measurement head CPU 35 ends the measurement and waits until the measurement head 11 reaches the stop position range R of the measurement head provided outside the maximum width S.

When the measuring head 11 reaches the stop position range R, the main CPU 43
Reaches S107 of the measurement control program, stops the measurement head 11, and feeds the printing plate 3 by the length L of the light beam in the Y-axis direction. In S108 to S109, the main CPU 43 receives all the measurement data files of the I-th measurement count obtained from the measurement head CPU 35, and calculates the picture area ratio based on the measurement data in S110. In S112, 1 is added to the count of the measurement counter I. Until the measurement over the entire length of the printing plate 3 is completed, S102 to S112 are repeated. Plate 3
When the measurement is completed over the entire width and length of
The main CPU 43 arrives at S113, and calculates the area ratio per ink key unit of the printing machine to be determined from the area ratio calculated at S110 using the parameters of the printing machine input manually previously.

 Therefore, this embodiment has the following effects.

That is, in the present embodiment, a simple structure is used in which the pattern area is measured by scanning the plate 3 with the measuring head 11 in the X-axis direction and feeding the plate 3 with the rollers 4 and 8 in the Y-axis direction. Therefore, unlike the conventional device using the optical deflector, the durability of the movable portion can be improved. Therefore, an apparatus having a long mean time to failure (MTBF) and a short mean time to repair (MTTR), that is, an extremely good operation rate can be obtained.

Further, since the measurement is performed by scanning the measuring head 11, unlike the conventional example using an optical deflector, the light source 30 and the printing plate 3 can be arranged close to each other and the height of the apparatus can be reduced. In addition, printing plate 3
Is sent in the Y-axis direction by the rollers 4 and 8, so that the depth does not require the entire length of the printing plate 3. Therefore, the whole apparatus can be designed small.

Furthermore, since the surface of the printing plate 3 is scanned with the light source 30 composed of a small-sized light beam without using a linear light source such as a fluorescent lamp, the printing plate 3 can be uniformly irradiated, and highly accurate measurement is possible. It is.

In addition, the control mechanism that scans the measuring head 11 is configured such that when the measuring head 11 moves in the X-axis direction, regardless of the moving speed of the measuring head 11, every time the measuring head 11 passes through the slit 13 of the scale member 27, the photo interrupter 28 Be emitted. Since the control method of inputting the measured value to the measuring head CPU 35 using the pulse as a trigger of sampling is adopted, the control of the servo motor 17 for driving the measuring head 11 can be performed by a simple method of only starting, returning, and stopping. Often, there is no need to synchronize the sampling timing with the movement of the measuring head 11. Accordingly, the stop position of the measuring head 11 is
Any position may be used as long as the portion of the scale member 27 without the slit 13, that is, within the stop position range R of the measurement head 11. Further, since the measuring head 11 starts from the stop position range R, the scale member
Since the photointerrupter 28 can pass through the slit 13 at the end of 27, the phase between the measurement position and the printing plate 3 is not out of order.

The number and the pitch of the slits 13 of the scale member 27 are fixed unless exchanged, and there is no contact with the same. Therefore, the number of times of sampling when the measuring head 11 scans the printing plate 3 of the same width once is always. You can do the same. Therefore, if the number of times of sampling is monitored and it is detected that this number is different from the predetermined number, erroneous sampling such as missing or excessive sampling can be detected, and appropriate sampling can be expected.

In order to perform such measurement control, the measurement head unit measurement control device 23 is provided in the measurement head 11 separately from the main measurement control device 24, and functions are shared, so that wiring from the main measurement control device 24 is minimized. The structure of the contact rail 20 and the contact brush 22 can be made simple and reliable, and the control program can be simplified.

The measurement data is stored in the measurement head unit measurement control device 23 while the measurement head 11 is moving, and is transmitted to the main measurement control device 24 until the measurement head 11 reaches the measurement head stop range R and stops. Without transmitting the measurement data, when the measurement head 11 is stopped, the measurement head section measurement head control device 23 transmits the measurement data to the main measurement control device 24 as a file using personal computer communication. Can be reduced.

In the above-described embodiment, the timing belt 15 and the timing pulleys 17 and 18 are used as the moving mechanism of the measuring head 11. However, instead of these, a feed screw mechanism using a ball screw and a ball nut is installed, and the measuring head 11 is moved. 11 may be movable. In addition, instead of the scale member 27 penetrating the slit 13 as in the above-described embodiment, a linear encoder and the measuring head 11 are used as pulse generating means for emitting a pulse in response to the movement of the measuring head 11. Various types of transmitters that generate a pulse each time they move by W may be used. That is, the measuring head 11 can move in the X-axis direction,
During this movement, the measuring head is moved by the width W of the light beam.
Every time 11 moves, it is sufficient if a pulse that triggers sampling can be input to the measurement head unit measurement control device 23,
Not limited to optically generated ones, it does not matter what kind of electrical, magnetic, etc., such as magnetic and capacitance.

Further, in the present embodiment, the arithmetic processing device is composed of the two devices of the main measurement control device 24 and the measurement head portion measurement control device 23, but these are integrated into one device by one CPU. The device may be made controllable. However, if they are separate, they have the advantages described above. Further, communication between the main measurement control device 24 and the measurement head unit measurement control device 23 is performed in a wired manner through the contact rail 20 and the contact brush 22. It may be wireless communication by combination with the element,
Instead of transferring data online, all data measured by the measurement head unit measurement control device 23 may be stored in a recording medium such as a floppy disk or a RAM cartridge, and the main measurement control device 24 may read the data. In addition, the structure, shape, and the like of this embodiment may be other structures as long as the object of the present invention can be achieved.

〔The invention's effect〕

As described above, according to the printing plate area ratio measuring apparatus of the present invention, an extremely good operation rate can be achieved, and the printing area ratio of the printing plate can be calculated with high accuracy.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an entire embodiment of the present invention, FIG. 2 is a partially cutaway side view, FIG. 3 is an enlarged plan view of a measuring head portion, FIG. 4 is a block diagram showing the configuration of a main measurement control unit and a measurement head unit measurement control unit as the arithmetic processing unit, and FIG. 5 is a measurement control program executed by the main measurement control unit and the measurement head unit measurement control unit. FIGS. 6, 7, and 8 are diagrams for explaining a conventional measuring method. FIG. 6 is a schematic diagram showing a measuring principle using an optical deflector, and FIGS. FIG. 8 is a schematic view showing a measurement principle using a linear light source. 4 ... feed roller, 8 ... press roller functioning as feed roller, 11 ... measuring head, 13 ... slit, 15 ...
Timing belt as scanning means, 17, 18 timing pulley as scanning means, 23 measuring head section measurement control device as arithmetic processing device, 24 main measurement control device as arithmetic processing device, 27 ... Scale member, 28 Photo interrupter as transmitter, 30 Light source 31, 31
Photoelectric converter.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masashi Sugimura 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (56) References JP-A-60-100710 (JP, A) JP-A-59 -65206 (JP, A) JP-A-58-82109 (JP, A)

Claims (1)

(57) [Claims] 1. A feed roller for transporting a printing plate in one direction while holding the front and back surfaces of the printing plate, and a reference physical quantity graduation arranged parallel to the feed roller and at a constant pitch. A scale member, a transmitter that reads the scale of the scale member and outputs a pulse, a light source that irradiates the plate surface with a light beam, and a photoelectric converter that receives reflected light from the plate and converts it into an electric signal. A scanning head for reciprocating the measuring head along the scale member; each time a pulse output from the transmitter is received, a signal from the photoelectric converter is sampled, and a picture of the printing plate is sampled. An arithmetic processing device for obtaining an area ratio, and a plate area ratio measuring device for a printing plate, comprising: