A method for printing photolithography positioning paper with graphic and text suspension dynamic effect

Abstract

The present invention relates to the technical field of printing devices, and in particular to a method for printing photolithographic positioning paper with a dynamic effect of suspended graphics and text, including positioning printing on photolithographic paper, determining whether an overprint deviation will occur and determining whether the overprint deviation is within the error range of a single print; adjusting the paper feed speed and correspondingly adjusting the rotation speed of the printing roller when the rotation angle meets the printing requirements, or adjusting the telescopic distance of the first support roller; determining whether the degree of deviation will change after several overprints, and predicting whether the photolithographic paper has a hidden danger of paper deformation under the current initial printing pressure based on changes in temperature and humidity, reflecting the tension of the photolithographic paper based on the actual pressure borne by the first support roller, or adjusting the paper feed speed or the initial printing pressure based on the predicted value of the comprehensive deformation. The present invention ensures accurate overprinting of the holographic pattern and the printed content by correspondingly adjusting the printing parameters of the printing device based on the predicted overprint deviation of the print.

Description

Technical Field

[0001] The present invention relates to the technical field of printing devices, and in particular to a method for printing photolithography positioning paper with a dynamic image and text suspension effect. Background Art

[0002] Laser registration paper and its printing process integrates three different manufacturing processes: laser paper, holographic registration hot stamping, and printing. This process precisely creates a registration security label on laser paper and then uses printing equipment to accurately overprint it, achieving the same results as the original process while reducing the procurement of registration labels and the processing of registration hot stamping. Compared to traditional printing methods, this technology effectively controls solvent residue and intermediate process waste, significantly reducing costs and achieving environmental protection. This technology represents a major breakthrough and transformation of traditional processes.

[0003] Chinese Patent Publication No.: CN116494663A discloses a digital proofing and printing method for photolithographic positioning paper, comprising the following steps: Step 1: Using a double-sided coated PET base, a UV molding method is used to replicate a PET base with a photolithographic information layer; Step 2: Digitally print graphic information on the other side of the PET base with the photolithographic information layer; Step 3: Use a laminating machine to composite the pre-coated high-gloss aluminum film with the photolithographic information layer of the PET base; Step 4. After completing the replication of the information layer and the printing layer using a double-sided coated PET substrate, glue is used to composite it with paper to obtain a finished product; Step 5: After the mounted paper is processed, semi-automatic equipment is used to complete the subsequent hot stamping, silk-screening, or embossing process according to the needs of the proofing process; Step 6: Use a knife plate to die-cut the printed matter into a finished box. It can be seen that the digital proofing and printing method for photolithographic positioning paper has the following problems:

[0004] Affected by the control of environmental temperature and humidity and the printing accuracy of the alignment of the photolithography layer and the ink layer during printing, there is a printing deviation after multiple overprinting. Summary of the Invention

[0005] To this end, the present invention provides a method for printing photolithography positioning paper with a dynamic effect of suspended graphics and text, so as to overcome the problem in the prior art of overprinting deviation after multiple overprintings due to the influence of environmental temperature and humidity control and the printing accuracy of the alignment of the photolithography layer and the ink layer during printing.

[0006] To achieve the above-mentioned object, the present invention provides a method for printing photolithography positioning paper with a dynamic effect of graphic suspension, comprising:

[0007] Producing a photoresist film with a holographic pattern and a positioning cursor Mark point, and laminating the photoresist film with paper to obtain photoresist paper;

[0008] Positioning and printing on the photolithographic paper, obtaining the feature image of the photolithographic paper including the Mark point, extracting the feature points, outputting the center coordinates and rotation angle of the feature point of the Mark point, and recording them as the actual position of the positioning cursor Mark point;

[0009] Predicting the relative positional relationship between the actual position and the theoretical position at the current paper feeding speed, calculating the deviation between the actual position and the theoretical position to determine whether an overprint deviation will occur and whether the overprint deviation is within an error range for a single printing;

[0010] determining whether an overprint deviation occurs, and adjusting the paper feed speed and the rotation speed of the printing cylinder accordingly, or adjusting the telescopic distance of the plurality of first support rollers, according to the deviation of the center coordinates when the rotation angle meets the printing requirements;

[0011] When determining that the overprint deviation is within the error range of a single print run, determining whether the degree of deviation will change after a number of overprint runs based on the maximum value of the deviation range and the product of the deviation amount and the number of overprint runs, and determining whether the cause of the overprint deviation within the error range of a single print run is tension, or whether there is a printing risk of paper deformation;

[0012] And based on the temperature and humidity changes, it is predicted whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure. According to the degree of the paper deformation printing risk, it is determined that the tension of the photolithographic paper is reflected according to the actual pressure borne by the first support roller, or the paper feed speed or the initial printing pressure is adjusted according to the predicted value of the comprehensive deformation amount;

[0013] Predicting the actual ink layer thickness after the initial printing pressure changes, determining whether the degree of change in the initial printing pressure exceeds an adjustment range, and accordingly changing the adjustment method for adjusting the printing parameters according to the degree of the potential risk of paper deformation;

[0014] The deviation range and the curing parameters of the UV light source are adjusted according to the change of the paper feeding speed, and the photolithographic paper is input into the next printing color group unit until all colors are printed to form the photolithographic positioning paper.

[0015] Furthermore, the process of determining whether an overprint deviation occurs includes:

[0016] Calculate the deviation between the actual position and the theoretical position to determine whether overprint deviation will occur. When the deviation is lower than the deviation range, it is determined that overprint deviation will not occur.

[0017] When the deviation exceeds the deviation range, it is determined that an overprint deviation will occur, and corresponding adjustment measures are taken according to the deviation of the center coordinates;

[0018] When the deviation amount is within the deviation range, it is determined that the overprint deviation is within the error range of a single printing, and whether the degree of deviation will change after several overprints is determined.

[0019] Furthermore, the process of determining whether the rotation angle meets the printing requirements includes:

[0020] When determining whether an overprint deviation has occurred, if the product of the difference between the rotation angle and the theoretical rotation angle and the distance between the center coordinate and the printing point is less than the difference evaluation angle, the paper feed speed is adjusted according to the deviation of the center coordinate and the rotation speed of the printing cylinder is adjusted accordingly, or the extension and retraction distance of the plurality of first support rollers is adjusted;

[0021] If the product of the difference between the rotation angle and the theoretical rotation angle and the distance between the center coordinate and the printing point is greater than or equal to the difference evaluation angle, printing is stopped and a warning signal is issued.

[0022] Furthermore, the paper feeding speed is increased or decreased and the telescopic distance of the first supporting roller is increased or decreased according to the difference between the abscissa and ordinate of the central coordinate and the abscissa and ordinate of the theoretical coordinate.

[0023] Furthermore, when it is determined that the overprint deviation is within the error range of a single printing, it is predicted based on the temperature and humidity changes whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure;

[0024] Calculate the predicted value of the comprehensive deformation according to the change of the ambient temperature and the reference temperature, the change of the ambient humidity and the reference humidity, and the initial printing pressure of the current printing cylinder;

[0025] When the predicted value of the comprehensive deformation is less than or equal to the first standard value, it is determined that there is no hidden danger of paper deformation under the current printing pressure, and the tension of the photolithographic paper is determined;

[0026] When the predicted value of the comprehensive deformation is greater than the first standard value, it is determined that there is a hidden danger of paper deformation under the current printing pressure, and the ambient temperature and humidity are controlled and adjusted to reduce the ambient temperature and humidity.

[0027] Furthermore, when there is a hidden danger of paper deformation under the current printing pressure,

[0028] When the predicted value of the comprehensive deformation is greater than the first standard value and less than or equal to the second standard value, it is determined that the degree of the hidden danger of paper deformation printing is within a critical range, and the paper feeding speed is reduced;

[0029] When the predicted value of the comprehensive deformation amount is greater than the second standard value, it is determined that the degree of the hidden danger of paper deformation printing exceeds a critical range, and the initial printing pressure is reduced.

[0030] Furthermore, the process of determining the tension on the photolithographic paper includes detecting the actual pressure on the first supporting roller in real time;

[0031] When the actual pressure is within the standard pressure range, it is determined that the tension applied to the photolithographic paper during the actual printing process is neither lower than nor higher than the tolerance range;

[0032] When the actual pressure is lower than or exceeds the standard pressure range, it is determined that the tension on the photolithographic paper during the actual printing process is lower than or exceeds the tolerance range, and the paper feeding speed of the printing device is increased or decreased.

[0033] Furthermore, after the initial printing pressure is reduced, the actual ink layer thickness is calculated according to a quantitative relationship between the initial printing pressure and the actual ink layer thickness;

[0034] If the actual ink layer thickness is greater than the critical ink layer thickness, it is judged that the reduction in initial printing pressure causes the ink layer thickness to change beyond the range, and the degree of reduction in the initial printing pressure exceeds the adjustment range. The adjustment method of adjusting the printing parameters according to the degree of hidden dangers of paper deformation printing is changed.

[0035] Furthermore, the degree of reduction of the initial printing pressure is reduced and the paper feeding speed is reduced according to the ratio of the critical ink layer thickness to the actual ink layer thickness.

[0036] Furthermore, after the paper feeding speed increases, the minimum value of the deviation range is reduced according to the ratio of the paper feeding speed before the increase to the paper feeding speed after the increase, and the maximum value of the deviation range is increased according to the ratio of the paper feeding speed after the increase to the paper feeding speed before the increase;

[0037] After the paper feeding speed increases or decreases, the illumination intensity of the UV light source is adjusted or the height of the UV light source is lowered according to the change in the paper feeding speed.

[0038] Compared with the existing technology, the beneficial effect of the present invention is that the core of the photolithography positioning paper lies in the precise positioning of the holographic pattern, so it is necessary to first produce a photolithography film with a holographic effect; after the photolithography film is produced, a laminating process is carried out, and perfect process parameter control and a directional stretching laminating machine are the guarantee of the holographic positioning paper; the core challenge of the photolithography positioning paper lies in the precise alignment of the holographic pattern and the printed content. This method ensures the precise overprinting of the holographic pattern (photolithography layer) and the printed content (ink layer) by predicting the printed overprint deviation and adjusting the printing parameters of the printing device accordingly, and ensures the dynamic floating effect of the image and text of the photolithography positioning paper.

[0039] Furthermore, high-end fields such as cigarette packaging and medicine packaging usually require lateral and longitudinal errors less than the millimeter level, with no blur or breakage in the holographic pattern and uniform ink coverage. This method calculates the deviation between the actual and theoretical positions of the positioning cursor Mark point at the current paper feed speed based on the relative positional relationship between the actual and theoretical positions of the positioning cursor Mark point, determines whether overprint deviation will occur, and divides the deviation into three types according to the deviation range. After determining that overprint deviation will occur, the overprint parameters of the printing device are adjusted according to the specific deviation of the overprint deviation when the rotation angle meets the requirements. That is, the paper feed speed is adjusted according to the coordinate difference between the center coordinate and the theoretical coordinate to reduce the lateral coordinate deviation when the photolithographic paper reaches the printing roller, or the telescopic distance of several first support rollers is adjusted to reduce the longitudinal coordinate deviation of the Mark point of the photolithographic paper, and dynamic correction is performed to ensure that the holographic pattern is aligned with the printed content. Since each color group shares the same Mark point reference during the printing process, it is necessary to ensure the consistency of multiple overprints. After determining that overprint deviation will occur within the error range of a single print, it is determined that the cause needs to be analyzed and corresponding adjustments need to be made to avoid error accumulation.

[0040] Furthermore, since the photolithographic paper absorbs moisture or expands due to temperature increase, there is a risk of deformation of the photolithographic paper. The moisture absorption and expansion of the paper will cause overprint deviation, and the initial printing pressure that the photolithographic paper bears between the second support roller and the printing cylinder will increase the degree of tension and stretching of the photolithographic paper. The method predicts whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure based on changes in ambient temperature and humidity. When there is a printing risk of paper deformation, the risk level of the printing risk is determined, and appropriate adjustment measures are taken according to the risk level. Within a safe range, the deformation risk can be ignored. At a moderate level, it is preferred to reduce the tension on the photolithographic paper by reducing the paper feed speed, thereby reducing the tensile deformation of the photolithographic paper. The risk of subsequent adjustments caused by changing the printing pressure is avoided. In severe cases, it is necessary to reduce the initial printing pressure applied by the printing roller to the photolithographic paper and correspondingly reduce the impact of changing the printing pressure on the printing process of the overprinted photolithographic paper; and when there is no hidden danger of paper deformation under the current initial printing pressure, the tension of the photolithographic paper is reflected according to the force condition of the first support roller, and it is judged whether the actual tension borne by the photolithographic paper is within the appropriate range, and whether the cause of the overprint offset within the error range of a single print is tension, so as to avoid overprint offset caused by stretching or shrinkage; improve the adaptability to environmental parameters and the flexibility of adjusting the printing process of the photolithography positioning paper.

[0041] Furthermore, changes in printing pressure directly affect the thickness of the ink layer covering the photolithographic paper after printing. The increase in the thickness of the ink layer may cause the holographic effect of the photolithographic paper to be covered by the printing ink after overprinting the photolithographic paper. The corresponding reason is that the covering ink layer is too thick due to the reduction in printing pressure. When the degree of hidden danger of paper deformation printing exceeds the critical range, the method reduces the initial printing pressure. According to the actual ink layer thickness after the calculated initial printing pressure is reduced, the influence of reducing the initial printing pressure on the holographic effect of the photolithographic layer of the photolithographic paper is judged. When the reduction in the initial printing pressure causes the ink layer thickness to change beyond the range, the degree of reduction of the initial printing pressure is reduced and the reduction is reduced by The paper feed speed compensates for the adjustment of the printing risk of paper deformation, and reduces the impact on the holographic effect by changing the adjustment method of adjusting the printing parameters according to the risk level of the paper deformation printing risk; at the same time, since the power density of the UV light source affects the curing effect of the ink layer, the UV ink may generate large internal stress during the curing process, affecting the adhesion of the ink to the printing material; this method increases the detection accuracy of the overprint deviation by correspondingly expanding the deviation range of detecting the overprint deviation after adjusting the paper feed speed, and adjusts the curing parameters of the UV light source according to the change of the paper feed speed, thereby reducing the impact of the paper feed speed on the subsequent curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of the process of printing a photolithography positioning paper with a dynamic floating image and text effect according to an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of the structure of the printing color group unit of the photolithography positioning paper printing device in an embodiment of the present invention;

[0044] Figure 3 Schematic diagram of a process for predicting overprint deviation in an embodiment of the present invention;

[0045] Figure 4 Schematic diagram of a process for determining a potential printing risk of paper deformation under a current printing pressure in an embodiment of the present invention;

[0046] In the figure: 1-photolithographic paper, 2-printing roller, 3-second support roller, 4-first support roller, 5-doctor blade, 6-gravure roller, 7-ink tank, 8-water purification roller, 9-ink transfer roller, 10-UV light source, 11-detection mechanism. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0048] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0050] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] See also Figure 1-Figure 4 As shown, Figure 1 Schematic diagram of the process of printing a photolithography positioning paper with a dynamic floating image and text effect according to an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the printing color group unit of the photolithography positioning paper printing device in an embodiment of the present invention; Figure 3 Schematic diagram of a process for predicting overprint deviation in an embodiment of the present invention; Figure 4 Schematic diagram of a process for determining a potential printing risk of paper deformation under current printing pressure in an embodiment of the present invention.

[0052] The method for printing photolithographic positioning paper with a dynamic floating image and text effect in an embodiment of the present invention includes:

[0053] Step S1, manufacturing a photoresist film with a holographic pattern and a positioning cursor Mark point, and laminating the photoresist film with paper to obtain photoresist paper;

[0054] Step S2, positioning and printing on the photolithographic paper, obtaining the feature image of the photolithographic paper including the Mark point, extracting the feature point, outputting the center coordinates and rotation angle of the feature point of the Mark point, and recording them as the actual position of the positioning cursor Mark point;

[0055] Specifically, the paper feeding mechanism feeds the photolithographic paper into the printing device, and the detection mechanism of the printing device detects the mark points on the holographic film on the photolithographic paper and adjusts the position of the paper to ensure the overprinting accuracy;

[0056] In this embodiment, when making a photoresist film, invisible mark points (such as micro text or dot matrix) are embedded in the photoresist pattern, which is suitable for high precision requirements. The printing device includes several printing color group units, each unit is responsible for one color.

[0057] Step S3, predicting the relative positional relationship between the actual position and the theoretical position at the current paper feeding speed, calculating the deviation between the actual position and the theoretical position to determine whether an overprint deviation will occur and whether the overprint deviation is within the error range of a single printing;

[0058] Step S4, determining whether an overprint deviation occurs, and adjusting the paper feed speed and the rotation speed of the printing cylinder accordingly, or adjusting the telescopic distance of the first support rollers, according to the deviation of the center coordinates when the rotation angle meets the printing requirements;

[0059] Step S5: When it is determined that the overprint deviation is within the error range of a single printing run, whether the degree of deviation will change after a number of overprints is determined based on the maximum value of the deviation range and the product of the deviation amount and the number of overprints, and whether the cause of the overprint deviation within the error range of a single printing run is tension, or whether there is a printing risk of paper deformation;

[0060] Step S6: predicting whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure based on the temperature and humidity changes; determining whether the tension of the photolithographic paper is reflected by the actual pressure on the first support roller based on the degree of the printing risk of paper deformation; or adjusting the paper feed speed or the initial printing pressure based on the predicted value of the comprehensive deformation;

[0061] Step S7, predicting the actual ink layer thickness after the initial printing pressure changes, determining whether the degree of change in the initial printing pressure exceeds the adjustment range, and accordingly changing the adjustment method for adjusting the printing parameters according to the degree of the potential risk of paper deformation;

[0062] Step S8, adjusting the deviation range and the curing parameters of the UV light source according to the change in the paper feeding speed;

[0063] In step S9, the photolithographic paper enters the next printing color group unit until all colors are printed to form a photolithographic positioning paper.

[0064] The curing parameters include the light intensity of the UV light source and the height of the UV light source.

[0065] Specifically, the core of photolithography positioning paper lies in the precise positioning of the holographic pattern, so it is necessary to first produce a photolithography film with a holographic effect; after the photolithography film is produced, a laminating process is carried out. Perfect process parameter control and a directional stretching laminating machine are the guarantees of holographic positioning paper; the core challenge of photolithography positioning paper lies in the precise alignment of the holographic pattern and the printed content. This method ensures the precise overprinting of the holographic pattern (photolithography layer) and the printed content (ink layer) by predicting the printed overprint deviation and adjusting the printing parameters of the printing device accordingly, and ensures the dynamic floating effect of the image and text on the photolithography positioning paper.

[0066] When making the photoresist film, a positioning cursor (mark point) is pre-set for the CCD of the printing device to identify.

[0067] In this embodiment, a laser engraved positioning mark is used, and the laser engraved positioning mark adopts a combination mark of a cross line + a digital code in a circle.

[0068] During printing, the cursor is tracked in real time by a high-precision photoelectric sensor to ensure that the overprint error is ≤±0.3mm.

[0069] Specifically, a laser with a specific wavelength (such as 532nm) and spot diameter (30-50μm) is used to etch mark points on the photoresist film;

[0070] The mark points on the photoresist film are captured by a high-resolution visual camera and their precise coordinates are calculated using image processing algorithms.

[0071] When the visual camera captures the mark point, an infrared detection light source is used to enhance the contrast of the mark point.

[0072] In this embodiment, the positioning cursor Mark point is located in the upper middle photolithography area of ​​the photolithography paper.

[0073] The detection mechanism identifies the mark point through visual detection, obtains the characteristic image of the photolithography paper containing the mark point, extracts the characteristic point, locates the coordinates and calculates the output center coordinates (x, y) of the characteristic point and the rotation angle θ;

[0074] Specifically, the acquired feature image is preprocessed, Gaussian filtering is used to eliminate noise, and histogram equalization is used to enhance contrast;

[0075] SIFT feature detection is used to locate the Mark point. The Zernike moment algorithm is used to detect the edge and output the feature point center coordinates (x0, y0) and rotation angle θ0 of the Mark point, which are recorded as the actual position of the positioning cursor Mark point.

[0076] Predicting the relative positional relationship between the actual position and the theoretical position at the current paper feeding speed, and calculating the deviation Δd between the actual position and the theoretical position to determine whether an overprint deviation will occur;

[0077] Δd = [(x-x0)² + (y-y0)²] 1 / 2 + k·|θ-θ0|;

[0078] Where x and y are the coordinate values ​​of the theoretical position in the theoretical coordinates (x, y), θ is the theoretical rotation angle of the theoretical position, and k is the rotation weight coefficient;

[0079] In implementation, k is equal to 0.1 μm / °, and the theoretical position includes a preset theoretical rotation angle and theoretical coordinates (x, y).

[0080] When the deviation is lower than the deviation range, it is determined that no overprint deviation will occur;

[0081] When the deviation exceeds the deviation range, it is determined that an overprint deviation will occur, and corresponding adjustment measures are taken according to the deviation of the center coordinates;

[0082] When the deviation amount is within the deviation range, it is determined that the overprint deviation is within the error range of a single printing, and further analysis is conducted to determine whether the degree of deviation will change after several overprints and the cause of the overprint deviation within the error range of a single printing;

[0083] When determining whether an overprint deviation has occurred, if the product of the difference between the rotation angle θ0 and the theoretical rotation angle and the distance between the center coordinate and the printing point (|rotation angle - theoretical rotation angle| × distance between the center coordinate and the printing point) is less than the difference evaluation angle, the paper feed speed is adjusted according to the deviation of the center coordinate and the rotation speed of the printing cylinder is adjusted accordingly, or the extension and retraction distance of the plurality of first support rollers is adjusted;

[0084] Specifically, when x0 is less than or greater than x, the paper feeding speed is increased or decreased according to the difference between the center coordinate x0 and the theoretical coordinate x;

[0085] It is understandable that setting the relative relationship between the coordinate difference and the paper feeding speed is a conventional method used by practitioners in this field, and the conversion of the relative relationship between the coordinate difference and the paper feeding speed will not be further described here.

[0086] When y0 is less than or greater than y, the telescopic distance of the first supporting rollers is increased or decreased according to the difference between the center coordinate y0 and the theoretical coordinate y;

[0087] If the product of the difference between the rotation angle θ0 and the theoretical rotation angle and the distance between the center coordinate and the printing point is greater than or equal to the difference evaluation angle, printing is stopped and a warning signal is issued;

[0088] The deviation range is ±(0.05-0.2) mm, and the difference evaluation angle is 1°.

[0089] Specifically, high-end fields such as cigarette packaging and medicine packaging usually require lateral and longitudinal errors to be less than the millimeter level, with no blur or breakage in the holographic pattern and uniform ink coverage. This method calculates the deviation between the actual and theoretical positions of the positioning cursor Mark point at the current paper feed speed based on the relative positional relationship between the actual and theoretical positions of the positioning cursor Mark point, determines whether overprint deviation will occur, and divides the deviation into three types according to the deviation range. After determining that overprint deviation will occur, if the rotation angle meets the requirements, the overprint parameters of the printing device are adjusted according to the specific deviation of the overprint deviation. That is, the paper feed speed is adjusted according to the coordinate difference between the center coordinate and the theoretical coordinate to reduce the lateral coordinate deviation when the photolithographic paper reaches the printing roller, or the telescopic distance of several first support rollers is adjusted to reduce the longitudinal coordinate deviation of the Mark point of the photolithographic paper, and dynamic correction is performed to ensure that the holographic pattern is aligned with the printed content. Since each color group shares the same Mark point reference during the printing process, it is necessary to ensure the consistency of multiple overprints. After determining that overprint deviation will occur within the error range of a single print, it is determined that the cause needs to be analyzed and corresponding adjustments need to be made to avoid error accumulation.

[0090] When determining that the overprint deviation is within the error range of a single printing, determining whether the degree of deviation will change after a number of overprints based on whether the maximum value of the deviation range is greater than the product of the deviation amount and the number of overprints;

[0091] Specifically, when the maximum value of the deviation range is less than the product of the deviation amount and the number of overprints, it is determined that the deviation amount exceeds the deviation range after overprinting according to the number of overprints, and the degree of deviation changes. The paper feed speed is adjusted according to the deviation of the center coordinate and the rotation speed of the printing roller is adjusted accordingly, or the telescopic distance of several first support rollers is adjusted.

[0092] And based on the temperature and humidity changes, it is predicted whether the photolithographic paper has the risk of paper deformation under the current initial printing pressure, and deformation prediction and expansion compensation are performed. According to the degree of the paper deformation printing risk, the actual pressure borne by the first support roller is used to reflect the tension of the photolithographic paper, or the paper feed speed or the initial printing pressure is adjusted according to the predicted value of the comprehensive deformation amount;

[0093] Real-time detection of ambient temperature and humidity, and calculation of the predicted value of comprehensive deformation ε based on the change between ambient temperature and reference temperature, the change between ambient humidity and reference humidity, and the initial printing pressure of the current printing cylinder;

[0094] ε=(α1×ΔRH) + (α2×ΔT) + (Kp×ln(P / P0)) + β×(dRH / dt)×t;

[0095] Where α1 is the coefficient of thermal expansion of the lithographic paper, α2 is the coefficient of thermal expansion of the lithographic paper, ΔRH is the relative humidity change, ΔT is the temperature change, Kp is the pressure sensitivity coefficient, P is the initial printing pressure, P0 is the reference printing pressure, β is the creep coefficient, dRH / dt is the humidity change rate, and t is the unit time.

[0096] In the implementation, the value range of α1 is 0.012-0.018% / %RH, ΔRH=ambient humidity-reference humidity, ΔT=ambient temperature-reference temperature, reference temperature, reference humidity and reference printing pressure are preset values, and the value range of α2 is 8-12×10 -6 / ℃, Kp value range is 0.08-0.12, and β value range is 0.002%·h / %RH.

[0097] When the predicted value of the comprehensive deformation is less than or equal to the first standard value, it is determined that there is no hidden danger of paper deformation under the current printing pressure, and the tension of the photolithographic paper is determined;

[0098] When the predicted value of the comprehensive deformation is greater than the first standard value, it is determined that there is a hidden danger of paper deformation under the current printing pressure, and the ambient temperature and humidity are controlled and adjusted to reduce the ambient temperature and humidity;

[0099] When the predicted value of the comprehensive deformation is greater than the first standard value and less than or equal to the second standard value, it is determined that the degree of the hidden danger of paper deformation printing is within the critical range, and the paper feeding speed is reduced to reduce the risk of paper deformation;

[0100] Specifically, the paper feeding speed is reduced according to the ratio of the first standard value to the predicted value of the comprehensive deformation amount;

[0101] When the predicted value of the comprehensive deformation is greater than the second standard value, it is determined that the degree of the hidden danger of paper deformation printing exceeds the critical range, and the initial printing pressure is reduced;

[0102] Specifically, reducing the initial printing pressure by 10 N / cm² can reduce the predicted value of the comprehensive deformation by 0.018%. The initial printing pressure is reduced according to the difference between the second standard value and the predicted value of the comprehensive deformation.

[0103] Furthermore, the process of determining the tension on the photolithographic paper includes detecting the actual pressure on the first supporting roller in real time;

[0104] When the actual pressure is within the standard pressure range, it is determined that the tension applied to the photolithographic paper during the actual printing process is neither lower than nor higher than the tolerance range;

[0105] When the actual pressure is lower than or exceeds the standard pressure range, it is determined that the tension on the photolithographic paper during the actual printing process is lower than or exceeds the tolerance range, and the paper feeding speed of the printing device is increased or decreased;

[0106] Specifically, when the tension is lower than or exceeds the tolerance range, the paper feeding speed of the printing device is increased or decreased according to the ratio of the middle value of the standard pressure range to the actual pressure;

[0107] Among them, the first standard value is 0.05%, the second standard value is 0.15%, the standard pressure range is 0.5-1.2 MPa, and the number of overprints is a preset value.

[0108] Specifically, the photolithographic paper may be deformed due to moisture absorption or thermal expansion, and the moisture absorption and expansion of the paper may cause overprint deviation, and the initial printing pressure that the photolithographic paper bears between the second support roller and the printing cylinder may increase the degree of tension and stretching of the photolithographic paper. This method predicts whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure based on changes in ambient temperature and humidity, determines the degree of the printing risk when there is a printing risk of paper deformation, and takes appropriate adjustment measures based on the degree of the risk. The deformation risk can be ignored within a safe range, and at a moderate level, it is preferred to reduce the tension on the photolithographic paper by reducing the paper feed speed, thereby reducing the tensile deformation of the photolithographic paper. The risk of subsequent adjustments caused by changing the printing pressure is avoided. In severe cases, it is necessary to reduce the initial printing pressure applied by the printing roller to the photolithographic paper and correspondingly reduce the impact of changing the printing pressure on the printing process of the overprinted photolithographic paper; and when there is no hidden danger of paper deformation under the current initial printing pressure, the tension of the photolithographic paper is reflected according to the force condition of the first support roller, and it is judged whether the actual tension borne by the photolithographic paper is within the appropriate range, and whether the cause of the overprint offset within the error range of a single print is tension, so as to avoid overprint offset caused by stretching or shrinkage; improve the adaptability to environmental parameters and the flexibility of adjusting the printing process of the photolithography positioning paper.

[0109] The holographic effect of the lithographic paper may be covered by the ink. The corresponding reason is that the ink layer is too thick or the initial printing pressure is reduced. It is necessary to reduce the ink viscosity or optimize the printing pressure.

[0110] After the initial printing pressure is reduced, calculating the actual ink layer thickness according to a quantitative relationship between the initial printing pressure and the actual ink layer thickness;

[0111] Actual ink layer thickness = initial ink layer thickness × ; In the formula, k is the pressure sensitivity coefficient, ranging from 0.015 to 0.025, and P is the initial printing pressure after reduction;

[0112] If the actual ink layer thickness is greater than the critical ink layer thickness, it is determined that the ink layer thickness variation exceeds the range due to the reduction in the initial printing pressure, and the degree of reduction in the initial printing pressure exceeds the adjustment range, and the adjustment method of adjusting the printing parameters according to the degree of the hidden danger of paper deformation printing is changed;

[0113] reducing the degree of reduction of the initial printing pressure and reducing the paper feeding speed according to the ratio of the critical ink layer thickness to the actual ink layer thickness;

[0114] The initial ink layer thickness is a preset value set according to historical data of ink layer thickness after printing on photolithographic paper by a single printing color group unit, and the critical ink layer thickness is 5 μm.

[0115] UV printing is done by applying ink containing photosensitizer to photolithographic paper, and then irradiating it with ultraviolet light to cause the photosensitizer in the ink to undergo a chemical reaction and quickly solidify into a film; UV curing is a photochemical reaction, and liquid UV ink quickly solidifies under ultraviolet light.

[0116] The curing speed is affected by many factors, including the intensity and wavelength of the UV light source, the thickness of the ink layer, and the light transmittance of the printing material.

[0117] In this embodiment, the initial power density of the UV light source is 200 W / cm.

[0118] After the paper feeding speed increases, the minimum value of the deviation range is reduced according to the ratio of the paper feeding speed before the increase to the paper feeding speed after the increase, and the maximum value of the deviation range is increased according to the ratio of the paper feeding speed after the increase to the paper feeding speed before the increase;

[0119] After the paper feeding speed increases or decreases, adjusting the illumination intensity of the UV light source or lowering the height of the UV light source according to the change in the paper feeding speed;

[0120] Specifically, after the paper feeding speed increases, the light intensity of the UV light source is increased according to the ratio of the increased paper feeding speed to the paper feeding speed before the increase, and the height of the UV light source is lowered when the light intensity reaches the maximum power of the equipment; after the paper feeding speed decreases, the light intensity of the UV light source is decreased according to the ratio of the reduced paper feeding speed to the paper feeding speed before the decrease.

[0121] Specifically, the change in printing pressure directly affects the thickness of the ink layer covering the photolithographic paper after printing. The increase in the thickness of the ink layer may cause the holographic effect of the photolithographic paper to be covered by the printing ink after overprinting the photolithographic paper. The corresponding reason is that the covering ink layer is too thick due to the reduction in printing pressure. When the degree of hidden danger of paper deformation printing exceeds the critical range, the method reduces the initial printing pressure. According to the actual ink layer thickness after the calculated initial printing pressure is reduced, the influence of reducing the initial printing pressure on the holographic effect of the photolithographic layer of the photolithographic paper is judged. When the reduction in the initial printing pressure causes the ink layer thickness to change beyond the range, the degree of reduction of the initial printing pressure is reduced and the reduction is reduced by The paper feed speed compensates for the adjustment of the printing risk of paper deformation, and reduces the impact on the holographic effect by changing the adjustment method of adjusting the printing parameters according to the risk level of the paper deformation printing risk; at the same time, since the power density of the UV light source affects the curing effect of the ink layer, the UV ink may generate large internal stress during the curing process, affecting the adhesion of the ink to the printing material; this method increases the detection accuracy of the overprint deviation by correspondingly expanding the deviation range of detecting the overprint deviation after adjusting the paper feed speed, and adjusts the curing parameters of the UV light source according to the change of the paper feed speed, thereby reducing the impact of the paper feed speed on the subsequent curing.

[0122] like Figure 2 As shown, the printing color group unit of the printing device includes photolithography paper 1, a printing roller 2, a gravure roller 6, a first support roller 4, a second support roller 3, an ink transfer roller 9, a water purification roller 8, a doctor blade 5, an ink tank 7, a UV light source 10 and a detection mechanism 11.

[0123] In this embodiment, the detection mechanism is a visual camera with a detection light source, the visual camera can move along the transmission direction of the photolithography paper, the first support roller can be extended and retracted in the y-axis direction perpendicular to the transmission direction, and the UV light source can move in the z-axis direction perpendicular to the transmission direction.

[0124] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0125] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for printing photolithography positioning paper with a dynamic effect of graphic suspension, characterized in that: include: Producing a photoresist film with a holographic pattern and a positioning cursor Mark point, and laminating the photoresist film with paper to obtain photoresist paper; Positioning and printing on the photolithographic paper, obtaining the feature image of the photolithographic paper including the Mark point, extracting the feature points, outputting the center coordinates and rotation angle of the feature point of the Mark point, and recording them as the actual position of the positioning cursor Mark point; Predicting the relative positional relationship between the actual position and the theoretical position at the current paper feeding speed, calculating the deviation between the actual position and the theoretical position to determine whether an overprint deviation will occur and whether the overprint deviation is within an error range for a single printing; determining whether an overprint deviation occurs, and adjusting the paper feed speed and the rotation speed of the printing cylinder accordingly, or adjusting the telescopic distance of the plurality of first support rollers, according to the deviation of the center coordinates when the rotation angle meets the printing requirements; When determining that the overprint deviation is within the error range of a single print run, determining whether the degree of deviation will change after a number of overprint runs based on the maximum value of the deviation range and the product of the deviation amount and the number of overprint runs, and determining whether the cause of the overprint deviation within the error range of a single print run is tension, or whether there is a printing risk of paper deformation; And based on the temperature and humidity changes, it is predicted whether the photolithographic paper has a printing risk of paper deformation under the current initial printing pressure. According to the degree of the paper deformation printing risk, it is determined that the tension of the photolithographic paper is reflected according to the actual pressure borne by the first support roller, or the paper feed speed or the initial printing pressure is adjusted according to the predicted value of the comprehensive deformation amount; Predicting the actual ink layer thickness after the initial printing pressure changes, determining whether the degree of change in the initial printing pressure exceeds an adjustment range, and accordingly changing the adjustment method for adjusting the printing parameters according to the degree of the potential risk of paper deformation; Adjusting the deviation range and the curing parameters of the UV light source according to the change in the paper feeding speed; The process of determining the rotation angle that meets printing requirements includes: When determining whether an overprint deviation has occurred, if the product of the difference between the rotation angle and the theoretical rotation angle and the distance between the center coordinate and the printing point is less than the difference evaluation angle, the paper feed speed is adjusted according to the deviation of the center coordinate and the rotation speed of the printing cylinder is adjusted accordingly, or the extension and retraction distance of the plurality of first support rollers is adjusted; increasing or decreasing the paper feeding speed and increasing or decreasing the telescopic distance of the first supporting roller according to the difference between the abscissa and ordinate of the center coordinate and the abscissa and ordinate of the theoretical coordinate; If the product of the difference between the rotation angle and the theoretical rotation angle and the distance between the center coordinate and the printing point is greater than or equal to the difference evaluation angle, printing is stopped and an early warning signal is issued.

2. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 1, characterized in that: The process for determining if overprint deviation will occur includes: Determine whether overprint deviation will occur based on the deviation between the actual position and the theoretical position. When the deviation is below the deviation range, it is determined that overprint deviation will not occur. When the deviation exceeds the deviation range, it is determined that an overprint deviation will occur, and corresponding adjustment measures are taken according to the deviation of the center coordinates; When the deviation amount is within the deviation range, it is determined that the overprint deviation is within the error range of a single printing, and whether the degree of deviation will change after several overprints is determined.

3. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 2, characterized in that: When determining that the overprint deviation is within the error range of a single print run, predict whether the photolithographic paper has a potential printing risk of paper deformation under the current initial printing pressure based on temperature and humidity changes; Calculate the predicted value of the comprehensive deformation according to the change of the ambient temperature and the reference temperature, the change of the ambient humidity and the reference humidity, and the initial printing pressure of the current printing cylinder; When the predicted value of the comprehensive deformation is less than or equal to the first standard value, it is determined that there is no hidden danger of paper deformation under the current printing pressure, and the tension of the photolithographic paper is determined; When the predicted value of the comprehensive deformation is greater than the first standard value, it is determined that there is a hidden danger of paper deformation under the current printing pressure, and the ambient temperature and humidity are controlled and adjusted to reduce the ambient temperature and humidity.

4. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 3, characterized in that: When there is a hidden danger of paper deformation under the current printing pressure, According to the predicted value of the comprehensive deformation being greater than the first standard value and less than or equal to the second standard value, it is judged that the degree of the hidden danger of paper deformation printing is within the critical range, and the paper feeding speed is reduced; According to the fact that the predicted value of the comprehensive deformation is greater than the second standard value, it is judged that the hidden danger degree of the paper deformation printing risk exceeds the critical range, and the initial printing pressure is reduced.

5. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 4, characterized in that: The process of determining the tension of the photolithographic paper includes detecting the actual pressure borne by the first supporting roller in real time; When the actual pressure is within the standard pressure range, it is determined that the tension applied to the photolithographic paper during the actual printing process is neither lower than nor higher than the tolerance range; When the actual pressure is lower than or exceeds the standard pressure range, it is determined that the tension on the photolithographic paper during the actual printing process is lower than or exceeds the tolerance range, and the paper feeding speed of the printing device is increased or decreased.

6. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 5, characterized in that: After the initial printing pressure is reduced, calculating the actual ink layer thickness according to a quantitative relationship between the initial printing pressure and the actual ink layer thickness; If the actual ink layer thickness is greater than the critical ink layer thickness, it is judged that the reduction in initial printing pressure causes the ink layer thickness to change beyond the range, and the degree of reduction in the initial printing pressure exceeds the adjustment range. The adjustment method of adjusting the printing parameters according to the degree of hidden danger of paper deformation printing is changed.

7. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 6, characterized in that: The degree of reduction of the initial printing pressure is reduced and the paper feeding speed is reduced according to the ratio of the critical ink layer thickness to the actual ink layer thickness.

8. The method for printing photolithography positioning paper with a dynamic floating image and text effect according to claim 7, characterized in that: After the paper feeding speed increases, the minimum value of the deviation range is reduced according to the ratio of the paper feeding speed before the increase to the paper feeding speed after the increase, and the maximum value of the deviation range is increased according to the ratio of the paper feeding speed after the increase to the paper feeding speed before the increase; After the paper feeding speed increases or decreases, the illumination intensity of the UV light source is adjusted or the height of the UV light source is lowered according to the change in the paper feeding speed.

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