JP2001062980A - Gravure engraving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gravure engraving device for easily carrying out the gravure work even in the case of using combinedly an etching process after engraving. SOLUTION: The initial setting, the returning to a starting point and the like of respective sections of a device are carried out (S1). The selection of the engraving mode is performed by an operator (S2). In the case of using a regular gravure cylinder GC, a first engraving mode is selected (S3). In the case of using the gravure cylinder GC with an etching protective layer, the setting of a gravure engraving device is changed (S4), and the retraction of a flash removing means and the sensing for a boundary face between a protective layer and a copper plated layer in the cylinder are carried out. Then for the purpose of controlling the volume of a seal after etching to a desired value, an image data used when the engraving is carried out is corrected primarily in compliance with etching conditions (S5). Then the engraving is carried out (S6). Whether the following engraving work is present or not is judged (S7), and in the case the following engraving work is present, the step is restored to the original step (S1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravure engraving apparatus for engraving gravure printing cells on a gravure cylinder.

[0002]

2. Description of the Related Art In the field of flexible packaging used for vinyl packaging of various products, gravure printing using a gravure cylinder is used. There is a gravure engraving apparatus as an apparatus for forming a cell for gravure printing on this gravure cylinder, for example, a mechanical gravure engraving apparatus for engraving a cylinder surface by vibrating a diamond engraving needle with respect to the cylinder is known. is there. In the mechanical engraving type gravure engraving apparatus, the volume of the cell is determined by changing the vibration amount of the engraving needle according to the image data. Then, the amount of ink to be filled is determined by the change in the volume of the cell, and the change in the amount of ink reproduces shading during gravure printing.

[0003] The diamond cutting tool used for the engraving needle has a tip angle of, for example, about 120 degrees, and the cross-section of the engraving is substantially triangular due to the cutting tool shape. Therefore, in order to engrave a cell having a large cell volume, that is, a deep cell in order to increase the printing density of the vinyl package, the cell width must be necessarily increased.

[0004]

In the case of engraving with a high print density as described above, the conventional gravure engraving apparatus has a large cell width, so the number of engraving lines is low, and high-definition printing cannot be performed. Was. To prevent this,
It is conceivable to use a sharp diamond cutting tool with a small tip angle that can be engraved deeper, but in this case, the engraving needle is liable to break, which is not practical.

In order to solve this problem, a method of enlarging a cell after engraving by etching may be considered. That is, when engraving is performed on the gravure cylinder on which the protective layer for etching is applied, the protective layer on the cell is removed as the cell is formed. By etching this, only the engraved cell portion can be etched deeply.

An object of the present invention is to provide a gravure engraving apparatus which can easily perform an engraving operation even when an etching step is used after engraving.

[0007]

According to a first aspect of the present invention, there is provided an engraving head for processing a surface of a gravure cylinder, and a gravure printing cell is formed on the gravure cylinder in accordance with desired image data. A gravure engraving device for engraving, a first engraving mode for engraving a normal gravure cylinder under predetermined engraving conditions;
A second engraving mode for engraving the gravure cylinder with a protective layer for performing etching in a later step by correcting the engraving conditions is provided.

According to a second aspect of the present invention, in the first aspect, in the second engraving mode, the engraving condition is corrected based on an etching condition in an etching step.

According to a third aspect of the present invention, in the first or second aspect, in the second engraving mode, the engraving conditions are corrected based on at least one of a type and a thickness of the protective layer.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the engraving condition is corrected by correcting the image data.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the engraving condition is corrected by changing a distance between the gravure cylinder and the engraving head.

According to a sixth aspect of the present invention, in the first aspect of the invention, there is provided a burr removing means for removing a burr generated by engraving by contacting a peripheral surface of the gravure cylinder, and the second engraving. Prohibiting means for prohibiting use of the burr removing means in the mode.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the gravure cylinder and the protective layer are provided so as to be movable along an axial direction of the cylinder and over the protective layer. And a distance adjusting means for adjusting the distance of the engraving head to the gravure cylinder based on the detection result of the detecting means.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a gravure plate making step using both a gravure engraving step and an etching step as a premise of the present invention will be described with reference to FIG. FIG. 8 is a view showing a cross section near the cylinder surface in each step.

First, FIG. 8A shows a general copper plating layer a.
FIG. 4 is a cross-sectional view of the cylinder surface showing a state in which a protective layer b for etching is further formed on a gravure cylinder having a surface on which a gravure cylinder is formed. Here, the protective layer b is formed by applying and coating a resist material that is not corroded by an etchant, and for example, a rosin-based, acrylic resin-based, or cellulose-based resist material can be used. This resist material has considerably lower hardness than the copper plating. It should be noted that other materials, for example, a hot-melt adhesive can be used as long as they are not corroded by the etching solution and are easily engraved.

When mechanical engraving is performed on the gravure cylinder with the protective layer b shown in FIG. 8A, engraving is performed, for example, in a cross section as shown in FIG. Is removed from the protective layer b. When the presence of the protective layer b can be ignored, the volume of the cell c by this engraving is almost the same as that of the conventional gravure engraving. That is, since the protective layer b made of the resist material has much lower hardness than the copper plating layer, the effect on entry of the engraving needle is almost negligible.

When the engraved gravure cylinder shown in FIG. 8B is immersed in an etching solution and etched, as shown in FIG. 8C, the portion where the protective layer b has been removed, that is, the copper plating layer a An etching process is performed from the opening formed in the above, and a cell d having a large cell volume is increased. Thereafter, the resist is peeled off as shown in FIG. 8D, and if necessary, a chrome plating layer f is formed as shown in FIG. 8E, thereby completing the gravure plate making. If the etching step is used in this manner, a cell d having a larger volume than the cell c formed in the normal engraving step can be formed.

In this embodiment, a gravure engraving apparatus that can use two types of gravure cylinders, a normal gravure cylinder and a gravure cylinder with a protective layer, will be described. First, FIG. 1 is a front view showing an example of a gravure printing apparatus according to the present invention, FIG. 2 is a top view of the apparatus, and FIG. 3 is a side sectional view of the apparatus.

In the figure, the gravure engraving device is a base 1
Headstock 2 and tailstock 3 for rotatably holding gravure cylinder GC, and gravure cylinder G
And an engraving mechanism 4 for engraving C.

The headstock 2 is fixed on the base 1, and rotatably supports a support portion 5 having a truncated conical end so as to fit into a mounting hole of the gravure cylinder GC. . The support section 5 is driven to rotate by a drive mechanism 6 including a motor and a belt.

On the other hand, the tailing table 3 also rotatably supports a support portion 7 having a conical tip so as to fit into the mounting hole of the gravure cylinder GC. Further, the tailstock 3 is movably mounted on a rail 8 provided on the base 1 so as to approach or separate from the headstock 2, and is driven by a driving mechanism including a motor 9 and a ball screw 10. The headstock 2 is configured to move toward or away from the headstock 2.

In this gravure engraving apparatus, the gravure cylinder GC is mounted on the headstock 2 as shown by a two-dot chain line in FIG.
The supporting mechanism 5 is sandwiched between the supporting part 5 on the side and the supporting part 7 on the tailstock 3 side, and is rotationally driven according to the rotation of the supporting part 5 by the driving mechanism 6.

The engraving mechanism 4 includes the gravure cylinder G
Sub-scanning table 11 movable along the axis of C
A sub-table 12 installed on the sub-scanning table 11, an engraving head 13 installed on the sub-table 12, and burr removing means 14 for removing burr after engraving.

The sub-scanning table 11 is a flat table-like member movable along a rail 15 provided on the base 1 in a direction parallel to the axis of the gravure cylinder GC.
It is driven to move by a motor 16 and a ball screw 17. A rail 18 is provided on the sub-scanning table 11 so as to be in contact with and away from the gravure cylinder GC. The sub-table 12 is movably mounted on the rail 18. The sub-table 12 holds the motor 1
The cylinder 9 and the ball screw 20 are moved in a direction of coming into contact with and separating from the cylinder surface.

Next, the engraving head 13 and the burr removing means 14 installed on the sub-table 12 are
This will be described with reference to FIG. 4 is a side view of the engraving head 13, and FIG. 5 is a front view of the same.

In the figure, an engraving head 13 includes a support 21 fixed on a sub-table 12 and a support 21.
And a head body 23 rotatably supported about a shaft 22. The head main body 21 is a housing frame having a storage space therein, and includes an engraving needle 24 therein.
And a capacitance sensor 26 for detecting the distance between the engraving needle 24 and the cylinder surface. Here, the engraving needle 24 is arranged so as to protrude from the head main body 21 toward the cylinder surface, and the capacitance type sensor 2
Reference numeral 6 denotes a position close to the engraving needle 24, which is arranged so that the distance to the cylinder surface can be detected. Note that another non-contact distance sensor may be used instead of the capacitance sensor 26.

On the other hand, the bottom of the head main body 23 is permanently mounted on a piezo driving means 27 fixed on the support table 21. The piezo driving means 27 is an actuator in which a plurality of piezo elements are stacked, and is capable of expanding and contracting by a very small amount in the vertical direction in FIGS. 4 and 5 by applying a predetermined voltage. In this configuration, the piezo driving means 2
Since the head body 23 can be rotated about the shaft 22 by the expansion and contraction of 7, the engraving needle 24 can be brought into and out of contact with the gravure cylinder GC by a very small amount in real time. In place of the piezo driving means 27,
An electromagnetic actuator or a combination of a high-speed motor and a ball screw may be used.

As shown in FIG. 5, the burr removing means 14 includes an arm member 28 arranged in a gate shape so as to surround a part of the side surface and a part of the upper surface of the head main body 23.
And 8 a cutter member 29 provided above the engraving needle 24. In the present embodiment, the cutter member 29 is formed of a diamond cutting tool like the engraving needle 24, and is located downstream of the engraving needle 24 when viewed from the rotation direction of the gravure cylinder GC.

The lower end of the arm member 28 has a substantially L-shaped structure as viewed from the side as shown in FIG.
8a is formed, and the vicinity of the L-shaped intersection is rotatably supported on the support base 21 about the shaft 30. A spring 31 is fitted between the short arm portion 28a of the arm member 28 and the sub-table 12, and urges the cutter member 29 so as to contact the cylinder surface.

On the other hand, an electromagnetic solenoid 32 is provided above the short arm portion 28a. When a predetermined voltage is applied to the electromagnetic solenoid 32, the short arm portion 28a is pushed down, and the cutter member 29 is moved. It can be selectively evacuated from the cylinder surface.

In FIG. 4, reference numeral 33 denotes the engraving needle 24.
This is a micrometer for manual adjustment for moving forward or backward with respect to the cylinder surface, and finely adjusts the position of the vibration mechanism 25.

Next, the structure of the vibration mechanism 25 of the engraving needle 24 will be described with reference to FIG. FIG. 6 is a perspective view of a general vibration mechanism 25. In the figure, a vibration mechanism 2
Reference numeral 5 denotes a torsion shaft 36 having torsional elasticity and having one end fixed to the base 35, and a stylus 37 fixed to the free end side of the torsion shaft 36 and having the engraving needle 24 at one end.
And a rotor portion 38 made of a substantially rhombic columnar magnetic material fixed to an intermediate portion of the torsion shaft; a winding 39 wound around the rotor portion 38; And a permanent magnet 41 for applying a magnetic force to the stator 40
Consists of

In this vibration mechanism, when an engraving signal based on image data is applied to the winding 39, a magnetic flux is generated in the rotor 38, so that the rotor 38 rotates by acting on the magnetic field of the stator 40. The engraving needle 24 is rotated by the rotational force of the rotor 38 via the torsion shaft 36 and the stylus 37.
Is driven. The engraving signal is obtained by superimposing a sinusoidal carry signal and a density signal representing the density of an image, and the engraving needle 24 vibrates by a vibration amount corresponding to the density signal at a cycle corresponding to the amplitude of the carry signal. It is configured as follows.

In the gravure engraving apparatus according to the present embodiment, first, the gravure cylinder GC is held between the headstock 2 and the tailstock 3. Then, the sub-table 12 is positioned with respect to the cylinder surface according to the cylinder diameter determined in advance. Then, the gravure cylinder GC is rotated, and the sub-scanning table 11 is moved in the axial direction of the gravure cylinder. Along with this, an engraving signal based on the image data is given to the engraving head 13, and the engraving needle 24 is vibrated to perform engraving. Thereby, an image is formed in a spiral shape on the surface of the gravure cylinder GC. Note that the sub-table 12 may be moved intermittently to form an image on the cylinder surface in a ring-shape.

In the case of engraving a general gravure cylinder GC, burrs generated by engraving can be removed by the burring removing means 14. On the other hand, when engraving the gravure cylinder GC with the protective layer, the burr removing means 14 is retracted from the cylinder surface by the electromagnetic solenoid 32 so as not to damage the protective layer.

On the other hand, in a general gravure cylinder GC, a base material such as an iron core, which is plated with copper, is used and is produced with high accuracy. The diameter has an error of, for example, about several tens of μm. Therefore, in a general gravure engraving apparatus, the engraving head 13 is provided with a contact member (shoe) for keeping the distance between the cylinder surface and the engraving head 13 constant.

However, in the gravure engraving apparatus according to the present embodiment, a gravure cylinder GC with a protective layer may be used in some cases. is there. Therefore, in the present embodiment, the distance to the cylinder surface is detected in a non-contact manner by the capacitance type sensor 26, and the piezo driving means 27 is driven in accordance with the detection result to drive the distance between the engraving needle 24 and the cylinder surface. The distance is adjusted to be constant.

On the other hand, a gravure cylinder G with a protective layer
Also in C, the thickness of the protective layer b may not be uniform. If the thickness of the protective layer b is not uniform, the distance between the engraving head 13 and the surface of the copper plating layer a must be kept constant, or the opening of the cell to be etched will not be constant. Therefore, in the present embodiment, the position of the boundary surface e between the copper plating layer a and the protective layer b in the gravure cylinder shown in FIG. 8A is detected. That is, the capacitance type sensor 26 can detect the thickness of the non-dielectric protective layer, so that the position of the boundary surface e can be grasped even if the protective layer b is present. Therefore, in this embodiment, when the gravure cylinder GC with the protective layer is used, the position of the engraving head is controlled by detecting the boundary surface e.

Next, the operation of the gravure engraving apparatus according to the present embodiment will be described with reference to the flowchart of FIG.
In the figure, first, in step S1, initialization of each section of the apparatus, origin return, and the like are performed. In the next step S2, the operator selects an engraving mode. That is, when the normal gravure cylinder GC is used, the first engraving mode is selected, and the process proceeds to step S3. In the first engraving mode, normal engraving processing is performed, but description thereof will be omitted.

On the other hand, when a gravure cylinder GC with a protective layer is used, the second engraving mode is selected in step S2, and the process proceeds to step S4 and subsequent steps. The second engraving mode is a mode for engraving a gravure cylinder with a protective layer.

The second engraving mode has the following two features as compared with the first engraving mode. First is the setting change of the gravure engraving device in step S4.
Specifically, as described above, the purpose is to evacuate the burr removing unit 14 and to change the control position of the engraving head by the capacitance type sensor 26. That is, when the second engraving mode is selected, the electromagnetic solenoid 32 operates to bring the cutter member 29 into a state where contact with the cylinder surface is prohibited. On the other hand, the engraving head is positioned according to the boundary surface e.

The other is correction of image data in step S5. In this step S5, the image data is corrected in advance according to the etching conditions in the post-process,
This is for controlling the volume of the cell to be formed to a desired value. For example, even if the cell is engraved under the same engraving conditions, the volume of the cell after the etching changes if the conditions of the etching process (for example, the etching time, the type and the activity of the etchant) are different. Therefore, the image data is corrected in advance in accordance with an etching processing apparatus to be used in a subsequent process.

In the apparatus according to the present embodiment, the increase ratio of the cell volume for each etching condition is previously obtained on a trial basis, and the image data is corrected in accordance with the increase ratio. For example, consider the following as a simple model case.
Note that this model case is for easy understanding, and the numerical values are not actual. In this example, if the increase rate of the cell volume by etching is 50%,
A cell having a cell volume of 60 at the time of engraving has a cell volume of 90 after etching. Here, if the operator sets the concentration increase by etching to a slightly lower limit, and wants to fit a cell having a cell volume of 50 to a cell volume of about 80, for example,
The image data is corrected in advance so that the cell volume at the time of engraving becomes 40.

The above example is a simplified model case. Actually, the increase rate of the cell volume changes depending on the area of the opening of the cell, and the increase rate of the cell volume of a cell having a small opening is smaller than that of a large cell. Become. Therefore, it is preferable that the above correction be performed for each cell size. By correcting the image data in advance according to the etching conditions as described above, the dimensions of the etched cells can be set to desired values.

On the other hand, depending on the etching conditions, a phenomenon called so-called side etching, in which etching proceeds in the cell width direction, may occur. This is the case where the copper plating portion under the protective layer is eroded by etching, and the cell width becomes larger than the cell opening formed in the copper plating layer. In such a case, the gap between the cells, that is, the width of a so-called generally embankment portion, becomes unduly small, which may adversely affect printing. Therefore, in the correction of the image data in step S5, the image data may be corrected so that the cell width at the time of engraving is reduced in advance in anticipation of an increase in the cell width due to such side etching.

In this embodiment, the dimensions of the etched cells can be set to desired values by correcting the image data in advance as shown in step S5. This is much easier than changing the degree of etching by changing the conditions on the etching apparatus side.

Returning to FIG. 7, in step S6, engraving is performed. Since the engraving operation itself is the same as the normal engraving operation in step S3, the following description is omitted.
Then, it is determined in step S7 whether there is a next engraving operation. If there is a next engraving operation, the process returns to step S1. If there is no next engraving operation, all the operations are completed.

[Other Embodiments]

(1) Means for observing the cylinder surface may be provided, and means for automatically judging whether it is a normal gravure cylinder or a gravure cylinder with a protective layer may be provided.
This can be achieved, for example, by providing means for detecting the color, reflectance, etc. of the cylinder surface and comparing them with a reference value obtained in advance.

(2) In the above embodiment, the hardness and thickness of the protective layer are neglected, but engraving conditions may be corrected according to the type and thickness of the protective layer. For example, test engraving is performed in advance for each type and thickness of the protective layer, and a change in cell size due to the presence of the protective layer is measured in advance. Based on this result, an optimal distance of the engraving needle to the cylinder surface and an amount of correction of image data may be set in advance in accordance with the type and thickness of the protective layer.

(3) Other engraving conditions may be changed between the first engraving mode and the second engraving mode. For example, in the second engraving mode, an increase in the cell volume can be expected by etching in a later step. Therefore, the engraving line number may be set higher than that in the first engraving mode, or an engraving needle having a wide tip angle may be used. Good.

(4) In the above embodiment, the engraving operation is performed after correcting all image data.
The engraving operation may be performed while sequentially correcting necessary image data or engraving signals during the engraving operation.

(5) In the above embodiment, the cell size after etching is adjusted to a desired value by correcting the image data. However, the distance between the engraving needle and the cylinder surface is varied. May be achieved.

(6) In the above embodiment, a mechanical gravure engraving apparatus is used. However, a laser gravure engraving apparatus that forms cells by performing perforation processing using beam energy can also be used.

[0055]

According to the invention described in claim 1, a normal gravure cylinder and a gravure cylinder with a protective layer can be selectively used, and when engraving the gravure cylinder with a protective layer, The volume of the engraved cell can be increased by a later etching process.

According to the second aspect of the present invention, since the engraving conditions are corrected according to the etching conditions, the dimensions of the cells after the etching can be set to desired values.

According to the third aspect of the present invention, since the engraving conditions are corrected according to the type and thickness of the protective layer, more accurate engraving can be performed.

According to the fourth aspect of the present invention, the dimensions of the etched cells can be set to desired values by correcting the image data.

According to the fifth aspect of the present invention, the size of the cell after etching can be set to a desired value by changing the distance between the engraving head and the cylinder surface.

According to the sixth aspect of the present invention, since the deburring means does not work during engraving of the gravure cylinder with the protective layer, breakage of the protective layer can be prevented.

According to the present invention, the boundary between the protective layer and the cylinder surface (copper-plated surface) is detected,
Since the distance between the engraving head and the gravure cylinder is adjusted, accurate engraving can be performed even when the thickness of the protective layer is not uniform.

[Brief description of the drawings]

FIG. 1 is a front view of a gravure engraving apparatus according to an embodiment of the present invention.

FIG. 2 is a top view of the gravure engraving apparatus.

FIG. 3 is a side sectional view of the gravure engraving apparatus.

FIG. 4 is a side view of an engraving head of the gravure engraving apparatus.

FIG. 5 is a front view of the engraving head.

FIG. 6 is a perspective view showing a vibration mechanism of the engraving needle.

FIG. 7 is a flowchart showing an operation procedure of the gravure engraving apparatus.

FIG. 8 is an explanatory diagram showing a state of a cell when an etching step is performed after an engraving step.

[Explanation of symbols]

 Reference Signs List 1 base 2 headstock 3 tailstock 4 engraving mechanism 13 engraving head 14 deburring means 24 engraving needle 25 vibration mechanism 26 capacitance type sensor 27 piezo driving means 28 arm member 29 cutter member 32 electromagnetic solenoid a copper plating layer b Protective layer c Cell after engraving d Cell after etching e Boundary surface f Chrome plating layer GC Gravure cylinder

Claims (7)

[Claims] 1. A gravure engraving apparatus comprising an engraving head for processing the surface of a gravure cylinder, and engraving a cell for gravure printing on the gravure cylinder according to desired image data. A first engraving mode in which engraving is performed under predetermined engraving conditions, and a second engraving mode in which engraving is performed on the gravure cylinder with a protective layer for performing etching in a later step by correcting the engraving conditions. And a gravure engraving device comprising: 2. The gravure engraving apparatus according to claim 1, wherein in the second engraving mode, the engraving conditions are corrected based on etching conditions in an etching step. 3. The gravure engraving apparatus according to claim 1, wherein in the second engraving mode, the engraving conditions are corrected based on at least one of a type and a thickness of the protective layer. 4. The gravure engraving apparatus according to claim 1, wherein said engraving conditions are corrected by correcting said image data. 5. The gravure engraving apparatus according to claim 1, wherein the engraving conditions are corrected by changing a distance between the gravure cylinder and the engraving head. 6. A burr removing means for removing burrs generated by engraving in contact with a peripheral surface of a gravure cylinder, and a prohibiting means for inhibiting use of said burring means in said second engraving mode. The gravure engraving device according to claim 1. 7. A detecting means provided movably along an axial direction of the cylinder, for detecting a position of a boundary surface between the gravure cylinder and the protective layer from above the protective layer; The gravure engraving apparatus according to claim 1, further comprising a distance adjusting unit configured to adjust a distance of the engraving head to the gravure cylinder based on a detection result.