A Standardization Method for Gravure Electro-Engraving Curves

Abstract

The present invention relates to a method for standardizing intaglio electro-engraving curves, comprising: selecting a multi-level gray scale step wedge pattern; using a reference electro-engraving machine to engrave the pattern onto a reference cylinder and print it on the surface of a printing substrate to obtain a reference gray scale step wedge printed pattern and measure the color density of each level of gray scale therein; using a debugging electro-engraving machine to engrave the pattern onto a debugging cylinder and print it on the surface of a printing substrate to obtain a debugging gray scale step wedge printed pattern and measure the color density of each level of gray scale therein; comparing the color density differences of each level of gray scale in the reference gray scale step wedge printed pattern and the debugging gray scale step wedge printed pattern, and adjusting the electro-engraving voltage when the debugging electro-engraving machine engraves each level of gray scale of the multi-level gray scale step wedge pattern, so as to complete the matching of the electro-engraving curves of the debugging electro-engraving machine and the reference electro-engraving machine. The present invention can reduce the differences between the patterns printed by multiple cylinders after different electro-engraving machines engrave the same pattern on multiple cylinders, increase the interoperability and utilization rate of different electro-engraving machines, and improve the production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of intaglio printing, and particularly relates to a method for standardizing intaglio electro-engraving curves. Background Art

[0002] Intaglio printing belongs to direct printing technology. Intaglio printing has the advantages of stable print quality, fast printing speed, etc. In intaglio printing, the ink contained in the intaglio pits can be directly imprinted onto the surface of the substrate. The shade levels of the printed pattern are determined by the size and depth of the pits. If the pits are deeper, the ink they contain is more, and the ink layer left on the substrate after imprinting is thicker; if the pits are shallower, the ink content is less, and the ink layer left on the substrate after imprinting is thinner. When performing intaglio printing, pits corresponding to the pattern to be printed are usually engraved on the roller. During printing, the ink is filled into the pits, the ink on the surface of the roller is scraped off by a doctor blade, and the roller and the substrate come into contact under a certain pressure to transfer the ink in the pits to the substrate, completing the printing process.

[0003] Currently, the engraving methods on the roller mainly include manual engraving, electronic engraving, laser engraving, etc. Electronic engraving is a process of directly engraving the roller with an electro-engraving machine. The electro-engraving machine scans the original manuscript through a scanning head to obtain density optical signals, which are converted into electrical signals through photoelectric conversion, and then transmitted to the output end after a series of processes to drive the engraving head of the electro-engraving machine to engrave on the roller. For different depth areas on the original manuscript, electro-engraving heads of the electro-engraving machine need to be driven to work with different electrical signals, that is, the strength of the vibration of the engraving head is controlled by different electro-engraving voltages to engrave dots with different depths on the surface of the roller. Currently, when engraving the same pattern on multiple rollers using multiple different electro-engraving machines, since there are certain differences in the settings such as the starting value of the electro-engraving voltage of different electro-engraving machines, the shades of the patterns printed by multiple rollers engraved by different electro-engraving machines will also be different, greatly affecting the printing quality. That is to say, in the prior art, usually only one electro-engraving machine can be used to engrave the same pattern on multiple rollers in sequence, resulting in low production efficiency and affecting the output. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for standardizing intaglio electro-engraving curves.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A method for standardizing intaglio electro-engraving curves includes the following steps:

[0007] S1: Select a multi-level gray scale ruler pattern;

[0008] S2: Use a reference engraving machine to engrave a multi - level gray scale ruler pattern onto a reference roller, and use the reference roller to print the multi - level gray scale ruler pattern on the surface of the printing substrate to obtain a reference gray scale ruler printed pattern; measure the color density D of each level of gray scale in the reference gray scale ruler printed pattern n ;

[0009] S3: Use a debugging engraving machine to engrave a multi - level gray scale ruler pattern onto a debugging roller, and use the debugging roller to print the multi - level gray scale ruler pattern on the surface of the printing substrate to obtain a debugging gray scale ruler printed pattern; measure the color density d of each level of gray scale in the debugging gray scale ruler printed pattern n ;

[0010] S4: Compare the color density differences of each level of gray scale between the reference gray scale ruler printed pattern and the debugging gray scale ruler printed pattern, and adjust the engraving voltage when the debugging engraving machine engraves each level of gray scale of the multi - level gray scale ruler pattern to complete the standardization matching of the engraving curves of the debugging engraving machine and the reference engraving machine.

[0011] Preferably, in step S1, the total number of levels of the multi - level gray scale ruler pattern is n, and n ranges from 10 to 25.

[0012] More preferably, the total number of levels n of the multi - level gray scale ruler pattern is 20.

[0013] Preferably, in steps S2 and S3, when printing with the reference roller and the debugging roller, the same black ink is used.

[0014] Preferably, in steps S2 and S3, when measuring the color density, the following steps are included: the illumination light source forms a measurement light beam through a focusing lens and irradiates the pattern to be measured. Part of the measurement light beam is absorbed by the pattern to be measured, and part of the measurement light beam is reflected by the pattern to be measured to form a reflected light beam. The reflected light beam at a set angle with the measurement light beam is collected by a collecting lens and transmitted to a receiver. The receiver converts the received light quantity into an electric quantity to obtain a measured electric quantity, compares the measured electric quantity with a reference electric quantity, and the difference between the two is the color density of the pattern to be measured.

[0015] More preferably, the set angle between the reflected light beam collected by the collecting lens and the measurement light beam is 30 - 60°.

[0016] Even more preferably, the set angle between the reflected light beam collected by the collecting lens and the measurement light beam is 45°.

[0017] More preferably, the receiver uses a photosensitive diode.

[0018] More preferably, the reference electric quantity is the electric quantity measured when the pattern to be measured is white.

[0019] Preferably, in step S4, compare the color density differences of each gray level in the reference gray scale printing pattern and the debug gray scale printing pattern, adjust the engraving voltage of the debug engraving machine when engraving each gray level of the multi-level gray scale pattern, and then repeat step S3 until the color densities of each gray level in the reference gray scale printing pattern and the debug gray scale printing pattern are the same.

[0020] Further preferably, when adjusting the engraving voltage of the debug engraving machine when engraving each gray level of the multi-level gray scale pattern: if the color density d of a certain gray level in the debug gray scale printing pattern n is greater than the color density D of the corresponding gray level in the reference gray scale printing pattern n , then reduce the engraving voltage of the debug engraving machine when engraving the corresponding gray level; if the color density d of a certain gray level in the debug gray scale printing pattern n is less than the color density D of the corresponding gray level in the reference gray scale printing pattern n , then increase the engraving voltage of the debug engraving machine when engraving the corresponding gray level.

[0021] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0022] The method of the present invention can realize the matching of the engraving curves of different engraving machines, so that after engraving the same pattern on multiple rollers with different engraving machines, the differences in the patterns printed by the multiple rollers are reduced, avoiding the problem that a pattern can only be engraved on one engraving machine, increasing the interoperability and utilization rate of different engraving machines, improving the convenience of production, enhancing the production efficiency, with a simple process, easy to operate, and good practicability. Description of the Drawings

[0023] Attached Figure 1 is a flowchart of the method for standardizing the intaglio engraving curve of the present invention;

[0024] Attached Figure 2 is a schematic diagram of the multi-level gray scale pattern of the present invention. Detailed Embodiments

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0027] A method for standardizing an intaglio electro-engraving curve, as Figure 1 shown, includes the following steps:

[0028] S1: Select a multi-level gray scale ruler pattern. Specifically:

[0029] The total number of levels of the multi-level gray scale ruler pattern is n, and n is preferably taken as 10 - 25. For example, when the total number of levels n of the multi-level gray scale ruler pattern is 10, the gray levels of the multi-level gray scale ruler pattern are 10, 20,..., 90, 100 in sequence.

[0030] S2:

[0031] (1) Select a reference electro-engraving machine, and use the reference electro-engraving machine to engrave the multi-level gray scale ruler pattern in S1 onto a reference roller. The electro-engraving voltage is different for each gray level when the reference electro-engraving machine engraves the multi-level gray scale ruler pattern.

[0032] (2) Use black ink and the reference roller to print the multi-level gray scale ruler pattern on the surface of the printing substrate to obtain a reference gray scale ruler printed pattern.

[0033] (3) Measure the color density D n of each gray level in the reference gray scale ruler printed pattern, which specifically includes the following steps:

[0034] Control a stable irradiation light source to form measurement light through a focusing lens. The measurement light irradiates a certain gray level of the reference gray scale ruler printed pattern. At this time, part of the measurement light is absorbed by the pattern, and the other part of the measurement light is reflected by the pattern to form reflected light.

[0035] Collect the reflected light at a set angle with the measurement light through a collecting lens. The set angle between the reflected light collected by the collecting lens and the measurement light can be taken as 30 - 60°, preferably 45°.

[0036] The reflected light continues to be transmitted to a receiver. The receiver can use a photodiode. The receiver converts the received light quantity into an electric quantity, that is, the measured electric quantity is obtained.

[0037] Compare the measured electric quantity with the reference electric quantity, where the reference electric quantity is the electric quantity measured through the above steps when the pattern is white. The measurement process of the reference electric quantity will not be elaborated here. The difference between the measured electric quantity and the reference electric quantity is the color density of a certain gray level of the reference gray scale ruler printing pattern;

[0038] And so on, measure the color density D of each gray level in the reference gray scale ruler printing pattern n .

[0039] S3:

[0040] (1) Select a debugging engraving machine that needs to be matched with the reference engraving machine, and use this debugging engraving machine to engrave the multi-level gray scale ruler pattern in S1 onto the debugging roller. The engraving voltage of the debugging engraving machine is different for each gray level when engraving the multi-level gray scale ruler pattern, and the model, parameters, etc. of the debugging roller are the same as those of the reference roller;

[0041] (2) Use black ink and the debugging roller to print the multi-level gray scale ruler pattern on the surface of the printing substrate to obtain a debugging gray scale ruler printing pattern. The black ink and printing substrate used here are the same as those used in step S2;

[0042] (3) Measure the color density d of each gray level in the debugging gray scale ruler printing pattern n , and this measurement process is the same as the measurement process of measuring the color density D of each gray level in the reference gray scale ruler printing pattern in step S2 n and will not be elaborated here.

[0043] S4:

[0044] Compare the color density differences of each gray level between the reference gray scale ruler printing pattern and the debugging gray scale ruler printing pattern, that is, compare the differences between d1 and D1, d2 and D2,..., d n and D n ;

[0045] Adjust the engraving voltage of the debugging engraving machine for each gray level when engraving the multi-level gray scale ruler pattern according to the comparison results. Specifically:

[0046] (1) If the color density d of each gray level in the debugging gray scale ruler printing pattern n corresponds to the same as the color density D of each gray level in the reference gray scale ruler printing pattern n , then complete the standardization matching of the engraving curves of the debugging engraving machine and the reference engraving machine;

[0047] (2) If the color density d of a certain gray level in the debugging gray scale ruler printing pattern n is greater than the color density D of the corresponding gray level in the reference gray scale ruler printing pattern n, the engraving voltage of the debugging engraving machine for engraving the corresponding gray level is reduced; if the color density d of a certain gray level in the printed pattern of the debugging gray scale ruler n is less than the color density D of the corresponding gray level in the printed pattern of the reference gray scale ruler n , the engraving voltage of the debugging engraving machine for engraving the corresponding gray level is increased; repeat step S2, that is, use the adjusted debugging engraving machine to engrave the pattern on the new debugging roller, then print and measure the color density, and then compare until the color density of each gray level in the printed pattern of the reference gray scale ruler and the printed pattern of the debugging gray scale ruler is the same, then the standardization matching of the engraving curves of the debugging engraving machine and the reference engraving machine is completed.

[0048] Embodiment

[0049] A method for standardizing an intaglio engraving curve includes the following steps:

[0050] S1: Select a 20-level gray scale ruler pattern, as Figure 2 shown, the gray levels of the 20-level gray scale ruler pattern are 5, 10, 15,..., 90, 95, 100 in sequence.

[0051] S2:

[0052] (1) Select a reference engraving machine, and use the reference engraving machine to engrave the multi-level gray scale ruler pattern in S1 onto the reference roller. The engraving voltages of the reference engraving machine for engraving each gray level in the multi-level gray scale ruler pattern are different, as shown in Table 1 specifically;

[0053] (2) Use black ink and the reference roller to print the multi-level gray scale ruler pattern on the surface of the printing substrate to obtain a reference gray scale ruler printed pattern;

[0054] (3) Measure the color density D of each gray level in the reference gray scale ruler printed pattern n , and the measurement results are shown in Table 1.

[0055] Table 1

[0056]

[0057] S3:

[0058] (1) Select a debugging engraving machine that needs to be matched with the reference engraving machine, and use the debugging engraving machine to engrave the multi-level gray scale ruler pattern in S1 onto the debugging roller. The engraving voltages of the debugging engraving machine for engraving each gray level in the multi-level gray scale ruler pattern are different, as shown in Table 2 specifically;

[0059] (2) Use black ink and the debugging roller to print the multi-level gray scale ruler pattern on the surface of the printing substrate to obtain a debugging gray scale ruler printed pattern;

[0060] (3) Measure the color density d of each gray level in the printed pattern of the calibration gray scale n , and the measurement results are shown in Table 2.

[0061] Table 2

[0062]

[0063] S4:

[0064] Compare the color density differences of each gray level between the reference gray scale printed pattern and the debug gray scale printed pattern, that is, compare the differences between d1 and D1, d2 and D2,..., d n and D n ; Adjust the electro-engraving voltage when the electro-engraving machine engraves each gray level of the multi-level gray scale pattern according to the comparison results; Repeat step S2, that is, use the adjusted electro-engraving machine to engrave the pattern on a new debug roller, then perform printing and measure the color density, and then compare again until the color densities of each gray level in the reference gray scale printed pattern and the debug gray scale printed pattern are the same, then complete the standardized matching of the electro-engraving curves of the debug electro-engraving machine and the reference electro-engraving machine. After the matching is completed, the electro-engraving voltages when the debug electro-engraving machine engraves each gray level of the multi-level gray scale pattern are shown in Table 3.

[0065] Table 3

[0066]

[0067]

[0068] After completing the standardized matching of the electro-engraving curves of the debug electro-engraving machine and the reference electro-engraving machine, the debug electro-engraving machine and the reference electro-engraving machine can be used to engrave any same pattern on two identical rollers respectively. After engraving, the differences between the patterns printed by the two rollers are extremely small, avoiding the problem that a pattern can only be engraved on one electro-engraving machine, increasing the interoperability and utilization rate of different electro-engraving machines, and improving the convenience of production.

[0069] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for standardizing intaglio electro-engraving curves, characterized in that: It includes the following steps: S1: Select a multi - level gray scale ruler pattern; S2: Use a reference engraving machine to engrave the multi - level gray scale ruler pattern onto a reference roller, and use the reference roller to print the multi - level gray scale ruler pattern on the surface of the printing substrate to obtain a reference gray scale ruler printed pattern; Measure the color density D of each gray level in the printed pattern of the measurement reference gray scale n ; S3: Use a debugging engraving machine to engrave the multi - level gray scale ruler pattern onto a debugging roller, and use the debugging roller to print the multi - level gray scale ruler pattern on the surface of the printing substrate to obtain a debugging gray scale ruler printed pattern; Measure the color density d of each gray level in the printed pattern of the measurement and debugging gray scale n ; S4: Compare the color density differences of each level of gray in the reference gray scale ruler printed pattern and the debugging gray scale ruler printed pattern, and adjust the engraving voltage when the debugging engraving machine engraves each level of gray of the multi - level gray scale ruler pattern to complete the standard matching of the engraving curves of the debugging engraving machine and the reference engraving machine.

2. The standardization method of the intaglio electro-engraving curve according to claim 1, wherein: In step S1, the total number of levels of the multi - level gray scale ruler pattern is n, and n ranges from 10 to 25.

3. The standardization method of the intaglio electro-engraving curve according to claim 2, characterized in that: The total number of levels n of the multi - level gray scale ruler pattern is 20.

4. The standardization method of the gravure engraving curve according to claim 1, characterized in that: In steps S2 and S3, when printing with the reference roller and the debugging roller, the same black ink is used.

5. The standardization method of the intaglio electro-engraving curve according to claim 1, characterized in that: In steps S2 and S3, when measuring the color density, it includes the following steps: The irradiation light source forms measurement light through a focusing lens and irradiates it onto the pattern to be measured. Part of the measurement light is absorbed by the pattern to be measured, and part of the measurement light is reflected by the pattern to be measured to form reflected light. The reflected light at a set angle with the measurement light is collected by a collecting lens and transmitted to a receiver. The receiver converts the received light quantity into an electric quantity to obtain a measured electric quantity, and compares the measured electric quantity with a reference electric quantity. The difference between the two is the color density of the pattern to be measured.

6. The standardization method of the gravure engraving curve according to claim 5, characterized in that: The set angle between the reflected light collected by the collecting lens and the measurement light is 30 - 60°.

7. The standardization method of the intaglio electro-engraving curve according to claim 6, characterized in that: The set angle between the reflected light collected by the collecting lens and the measurement light is 45°.

8. The standardization method of the intaglio electro-engraving curve according to claim 5, characterized in that: The reference electric quantity is the electric quantity measured when the pattern to be measured is white.

9. The standardization method of the intaglio electro-engraving curve according to claim 1, characterized in that: In step S4, compare the color density differences of each level of gray in the reference gray scale ruler printed pattern and the debugging gray scale ruler printed pattern, adjust the engraving voltage when the debugging engraving machine engraves each level of gray of the multi - level gray scale ruler pattern, and then repeat step S3 until the color densities of each level of gray in the reference gray scale ruler printed pattern and the debugging gray scale ruler printed pattern are the same.

10. The standardization method of the gravure engraving curve according to claim 9, characterized in that: When adjusting the electro-engraving voltage for each gray level of the multi-level gray scale ruler pattern engraved by the electro-engraving machine: If the color density d of a certain gray level in the printed pattern of the gray scale ruler n is greater than the color density of the corresponding gray level in the printed pattern of the reference gray scale ruler, then reduce the electro-engraving voltage when the electro-engraving machine engraves the corresponding gray level; If the color density d of a certain gray level in the printed pattern of the gray scale ruler n is less than the color density of the corresponding gray level in the printed pattern of the reference gray scale ruler, then increase the electro-engraving voltage when the electro-engraving machine engraves the corresponding gray level.

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