阅读说明：本技术 一种印材相对拉伸量的测量方法 (Method for measuring relative stretching amount of printing material ) 是由 高伟晋 包振健 李先军 陈聪 杨皓琨 于 2021-08-24 设计创作，主要内容包括：本申请公开了一种印材相对拉伸量的测量方法,所述相对拉伸量是指相对于正常印刷时设定张力下的承印材料,在印制过程中由于张力波动所产生的形变量,所述相对拉伸量既可为正也可为负,所述方法根据两色组图像采集时间间隔以及对应基准色组的纵向位置确定印材的相对拉伸量,根据所述相对拉伸量来校正套色参数,本申请提供的方法还适用于复卷,复合等需要控制张力的设备中。(The application discloses a method for measuring the relative stretching amount of a printing material, wherein the relative stretching amount refers to the deformation amount generated by tension fluctuation in the printing process relative to a printing material under the set tension in the normal printing process, the relative stretching amount can be positive or negative, the method determines the relative stretching amount of the printing material according to the image acquisition time interval of two color groups and the longitudinal position of a corresponding reference color group, and corrects color register parameters according to the relative stretching amount.)

1. A method for measuring the relative stretching amount of a printing material is characterized in that the method is used for measuring the relative stretching amount of a printing substrate with a larger stretching coefficient in a printing process, a printing device suitable for the method comprises a plurality of color groups, a measuring module is arranged at the downstream of each color group from the second color group along the paper feeding direction, each measuring module comprises a delay trigger plate and a processor, each two measuring modules to be measured form a stretching amount measuring group, the measuring module at the upstream in each stretching amount measuring group is marked as a first measuring module, each device in each measuring module is correspondingly marked as a first device, the processed physical amount is marked as a first physical amount, the measuring module at the downstream is marked as a second measuring module, each device in each measuring module is correspondingly marked as a second device, the physical quantity processed by the method is marked as a second physical quantity, and the measuring method comprises the following steps:

the method comprises the steps that a first processor obtains a first time interval and sends the first time interval to a second processor, wherein the first time interval is a time interval when a first delay trigger board is triggered twice;

the second processor obtains a second time interval, wherein the second time interval is the time interval of the second time delay trigger plate triggered twice, and the version cycle of the second time delay trigger plate triggered twice is the same as the version cycle of the first time delay trigger plate triggered twice;

the second processor obtains a first longitudinal deviation, wherein the first longitudinal deviation is a longitudinal deviation between the geometric center of the first target image and the geometric center of the first target image printed by the first target image;

the second processor obtains a second longitudinal deviation, wherein the second longitudinal deviation is a longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor;

the second processor acquires the paper feeding speed;

and the second processor calculates the relative stretching amount of the printing material according to the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

2. The method according to claim 1, wherein the calculating of the relative print material stretch is based on the first time interval, the second time interval, the first machine direction deviation, the second machine direction deviation, and the feed speed, and is specifically based on the following equation (1):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁formula (1)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing the speed of paper feed, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

3. The method according to claim 1 or 2, wherein the method of obtaining a first longitudinal deviation comprises:

acquiring a geometric center coordinate of a first target image;

acquiring geometric center coordinates of a first target image;

and calculating a first longitudinal deviation, wherein the first longitudinal deviation is the difference between the ordinate of the geometric center of the first target image and the ordinate of the geometric center of the first target image.

4. The method according to any one of claims 1 to 3, wherein the measuring method further comprises:

acquiring a first correction trigger distance and a second correction trigger distance of the previous version cycle;

acquiring a first actual trigger distance and a second actual trigger distance of the current edition week;

acquiring a first correction deviation and a second correction deviation;

and calculating the relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

5. The method according to any one of claims 1 to 4, wherein said calculating the sheet relative stretch amount from the first correction offset, the second correction offset, the first time interval, the second time interval, the first machine direction offset, the second machine direction offset, and the sheet feed speed is calculated in particular according to the following equation (2):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁+N₂-M₂+M₁-N₁formula (2)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing the speed of paper feed, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

6. The method according to any one of claims 1 to 5, wherein the first corrected trigger distance is a trigger distance theoretically corrected on the basis of the first actual trigger distance of the previous plate week based on the plate week for which the first corrected trigger distance was obtained; the second correction trigger distance is a trigger distance which is theoretically corrected on the basis of the version cycle of the acquired second correction trigger distance and the second actual trigger distance of the previous version cycle.

7. The method of claim 1, wherein the measuring method comprises:

the method comprises the steps that a first processor obtains a first distance interval and sends the first distance interval to a second processor, wherein the first distance interval is a paper feeding distance of a printing material during the two times of triggering of a first delay trigger board;

a second processor obtains a second distance interval, wherein the second distance interval is a paper feeding distance of a printing material during the period that a second time delay trigger plate is triggered twice, and the plate periphery of the second time delay trigger plate which is triggered twice is the same as the plate periphery of the first time delay trigger plate which is triggered twice;

the first processor acquires a first longitudinal deviation, and sends the first longitudinal deviation to the second processor, wherein the first longitudinal deviation is a longitudinal deviation between the geometric center of the first target image and the geometric center of the first target image printed by the first target image;

the second processor obtains a second longitudinal deviation, wherein the second longitudinal deviation is a longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor;

the second processor acquires the paper feeding speed;

and the second processor calculates the relative stretching amount of the printing material according to the first distance interval, the second distance interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

8. The method according to any of claims 1 to 7, wherein calculating the print material relative stretch from the first distance interval, the second distance interval, the first machine direction deviation, the second machine direction deviation, and the feed speed is calculated in particular from the following equation (3):

Δl＝ΔL₂-ΔL₁+y₂-y₁formula (3)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

9. The method according to any one of claims 1 to 8, wherein the measuring method further comprises:

acquiring a first correction trigger distance and a second correction trigger distance of the previous version cycle;

acquiring a first actual trigger distance and a second actual trigger distance of the current edition week;

acquiring a first correction deviation and a second correction deviation;

and calculating the relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

10. The method according to any one of claims 1 to 9, wherein said calculating the sheet relative stretch amount from the first correction offset, the second correction offset, the first time interval, the second time interval, the first machine direction offset, the second machine direction offset, and the sheet feed speed is calculated in particular according to the following equation (4):

Δl＝ΔL₂-ΔL₁+y₂-y₁+N₂-M₂+M₁-N₁formula (4)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

Technical Field

The application belongs to the field of printing, and particularly relates to a method for measuring relative stretching amount of a printing material.

Background

The multicolor group printing equipment is used for printing products with complicated patterns of colors, the multicolor group printing machine is generally used for printing the complicated patterns of the colors by nesting different color groups, and before formal printing, the printing machine is debugged to accurately align a plurality of color groups, so that the printed products meet the requirement of printing precision, and the process is called registration. High-quality printed products generally require higher registration accuracy, and in order to realize high-accuracy registration control, a registration deviation value needs to be measured accurately in time, so that the color register parameters are corrected in real time in the processes of machine adjustment and printing.

In the prior art, a method for detecting a register offset value in real time includes a registration scheme based on a visual method, and generally, the registration scheme based on the visual method first photographs a color scale group, identifies a color scale image according to the photographed image, and determines the register offset value according to the color scale image, however, for a yielding substrate to be printed, the yielding substrate may be stretched during a printing process, and particularly, during an acceleration and deceleration process of a printing device, the tension of the printing device fluctuates, which causes the deformation of the substrate to be printed, thereby causing a decrease in registration accuracy.

Disclosure of Invention

In order to solve the technical problems in the prior art, the application provides a method for measuring the relative stretching amount of a printing material, wherein the relative stretching amount refers to the deformation amount generated by tension fluctuation in the printing process relative to a printing material under a set tension in normal printing, the relative stretching amount can be positive or negative, the method determines the relative stretching amount of the printing material according to the image acquisition time interval of two color groups and the longitudinal position of the corresponding reference color group, and corrects the color register parameter according to the relative stretching amount.

The traditional method cannot carry out quantitative measurement of the stretching amount of the printing material, and can only indirectly obtain or control qualitative stretching or shortening according to the tension of equipment. The method and the device can be used for printing high-precision registration and can also be used for rewinding, compounding and other devices needing tension control.

The purpose of the application is realized by the following scheme:

a method for measuring the relative stretching amount of a printing material is used for measuring the relative stretching amount of a printing substrate with a larger stretching coefficient in a printing process, and is suitable for a unit type multi-color group printing device which comprises a plurality of color groups independent of each other, wherein a measuring module is arranged at the downstream of each color group from the second color group along the paper feeding direction, each measuring module comprises a time delay trigger plate and a processor, each two measuring modules to be measured form a stretching amount measuring group, the measuring module at the upstream in each stretching amount measuring group is marked as a first measuring module, each device in each measuring module is correspondingly marked as a first device, the physical quantity processed by each measuring module is marked as a first physical quantity, the measuring module at the downstream is marked as a second measuring module, each device in each measuring module is correspondingly marked as a second device, the physical quantity processed by the method is marked as a second physical quantity, and the measuring method comprises the following steps:

the method comprises the steps that a first processor obtains a first time interval and sends the first time interval to a second processor, wherein the first time interval is a time interval when a first delay trigger board is triggered twice;

the second processor obtains a second time interval, wherein the second time interval is the time interval of the second time delay trigger plate triggered twice, and the version cycle of the second time delay trigger plate triggered twice is the same as the version cycle of the first time delay trigger plate triggered twice;

the first processor acquires a first longitudinal deviation, and sends the first longitudinal deviation to the second processor, wherein the first longitudinal deviation is a longitudinal deviation between the geometric center of the first target image and the geometric center of the first target image printed by the first target image;

the second processor obtains a second longitudinal deviation, wherein the second longitudinal deviation is a longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor;

the second processor acquires the paper feeding speed;

and the second processor calculates the relative stretching amount of the printing material according to the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

In this implementation, the printing material relative stretch amount is calculated according to the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed, and specifically can be calculated according to the following formula (1):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁formula (1)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing the speed of paper feed, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

In this implementable manner, the method of acquiring a first longitudinal deviation comprises:

acquiring a geometric center coordinate of a first target image;

acquiring geometric center coordinates of a first target image;

and calculating a first longitudinal deviation, wherein the first longitudinal deviation is the difference between the ordinate of the geometric center of the first target image and the ordinate of the geometric center of the first target image.

Accordingly, the method of acquiring the second longitudinal deviation comprises:

acquiring a geometric center coordinate of a second target image;

acquiring geometric center coordinates of a second target image;

and calculating a second longitudinal deviation, wherein the second longitudinal deviation is the difference between the ordinate of the geometric center of the second target image and the ordinate of the geometric center of the second target image.

In this implementation, the measurement method may further include:

acquiring a first correction trigger distance and a second correction trigger distance of the previous version cycle;

acquiring a first actual trigger distance and a second actual trigger distance of the current edition week;

acquiring a first correction deviation and a second correction deviation;

and calculating the relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

Alternatively, the calculation of the print material relative stretch amount based on the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation, and the paper feed speed may be specifically calculated according to the following formula (2):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁+N₂-M₂+M₁-N₁formula (2)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing the speed of paper feed, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

In this implementation manner, the first corrected trigger distance is a trigger distance after theoretical correction is performed on the basis of the first actual trigger distance of the previous version week based on the version week for which the first corrected trigger distance is obtained; correspondingly, the second correction trigger distance is a trigger distance theoretically corrected on the basis of the second actual trigger distance of the previous version week based on the version week for which the second correction trigger distance is acquired.

In another implementable manner, the measurement method includes:

the method comprises the steps that a first processor obtains a first distance interval and sends the first distance interval to a second processor, wherein the first distance interval is a paper feeding distance of a printing material during the two times of triggering of a first delay trigger board;

a second processor obtains a second distance interval, wherein the second distance interval is a paper feeding distance of a printing material during the period that a second time delay trigger plate is triggered twice, and the plate periphery of the second time delay trigger plate which is triggered twice is the same as the plate periphery of the first time delay trigger plate which is triggered twice;

the method comprises the steps that a first processor obtains a first longitudinal deviation and sends the first longitudinal deviation to a second processor, wherein the first longitudinal deviation is the longitudinal deviation between the geometric center of a first target image and the geometric center of a first target image printed by the first target image;

the second processor obtains a second longitudinal deviation, wherein the second longitudinal deviation is a longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor;

the second processor acquires the paper feeding speed;

and the second processor calculates the relative stretching amount of the printing material according to the first distance interval, the second distance interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

In this implementation, calculating the print material relative stretch amount based on the first distance interval, the second distance interval, the first longitudinal deviation, the second longitudinal deviation, and the paper feed speed may specifically be calculated according to the following formula (3):

Δl＝ΔL₂-ΔL₁+y₂-y₁formula (3)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

Further, the method of acquiring the first longitudinal deviation and the second longitudinal deviation is the same as the method of acquiring the corresponding longitudinal deviation in the previous implementation.

In this implementation, the measurement method may further include:

acquiring a first correction trigger distance and a second correction trigger distance of the previous version cycle;

acquiring a first actual trigger distance and a second actual trigger distance of the current edition week;

acquiring a first correction deviation and a second correction deviation;

and calculating the relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

Alternatively, the calculation of the print material relative stretch amount based on the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation, and the paper feed speed may be specifically calculated according to the following formula (4):

Δl＝ΔL₂-ΔL₁+y₂-y₁+N₂-M₂+M₁-N₁formula (4)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

In this implementation manner, the first corrected trigger distance is a trigger distance after theoretical correction is performed on the basis of the first actual trigger distance of the previous version week based on the version week for which the first corrected trigger distance is obtained; correspondingly, the second correction trigger distance is a trigger distance theoretically corrected on the basis of the second actual trigger distance of the previous version week based on the version week for which the second correction trigger distance is acquired.

In a second aspect, the present application further provides a program for measuring a relative stretch amount of a printing material, the program being configured to implement the steps of the method for measuring a relative stretch amount of a printing material according to the first aspect.

In a third aspect, a computer readable storage medium has stored thereon computer instructions which, when executed by a processor, implement the steps of the method for measuring relative stretch of a sheet material according to the first aspect.

In a fourth aspect, a detection apparatus, the detection apparatus comprising: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the processor, and the instructions are executed by the at least one processor to cause the at least one processor to perform the method for measuring relative stretching of the printing material according to the first aspect.

Compared with the prior art, the method provided by the application is based on a visual scheme, the relative stretching amount of the printing material between any two color sets can be measured by utilizing the uniquely designed target form and the relative stretching amount measurement of the printing material between any two color sets of the specific measurement module, the relative stretching amount obtained according to the method is closer to a true value, and the measurement error reaches a pixel level.

Drawings

FIG. 1 is a schematic diagram of a printing apparatus suitable for use in a measurement method provided herein;

FIG. 2 shows a schematic representation of one embodiment of a plate-around target provided herein;

FIG. 3 is a flow chart illustrating a method for measuring relative stretch of a printing material according to the present application;

fig. 4 shows a flow chart of another method for measuring the relative stretching amount of the printing material provided by the application.

Description of the reference numerals

1-color group, 11-plate cylinder, 12-impression cylinder, 13-guide cylinder, 2-measuring module, 21-image collector, 22-light source, 23-time delay trigger plate, 24-sensor, 25-processor, 3-color register subsystem and 4-printing machine communication bus.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of methods consistent with certain aspects of the invention, as detailed in the appended claims.

The method for measuring the relative stretch of the printing material provided by the present application is explained in detail by specific examples.

First, a brief introduction is made to a usage scenario of the present solution.

Fig. 1 shows a schematic diagram of a printing apparatus suitable for use in the measurement method provided in the present application, and as shown in fig. 1, the multi-color set printer includes a plurality of color sets 1 and a plurality of measurement modules 2, and one measurement module 2 is arranged downstream of each color set 1 from the second color set 1 in the paper feeding direction.

In this example, each color registering subsystem 3 includes only one color set and a unique matching measurement module, that is, the measurement module performs registration detection only for the assigned unique color set, the detection of the misregistration values of the color sets is independent, and each measurement module is adjacent to the corresponding color set, so that the misregistration values of the color sets can be detected immediately after the printing of the color sets is completed, and not only is the detection efficiency higher, but also the accuracy of the detected misregistration values is higher.

As shown in fig. 1, each color group 1 includes a plate cylinder 11, an impression cylinder 12, and at least two guide cylinders 13, wherein the plate cylinder 11 is disposed opposite to the impression cylinder 12, a substrate to be printed is passed through and pressed by a slit between the plate cylinder 11 and the impression cylinder 12, the two guide cylinders 13 are respectively disposed on both sides of a pressing position of the plate cylinder 11 and the impression cylinder 12, and the measuring module 2 is disposed downstream of the downstream guide cylinder 13.

Taking the printing apparatus shown in fig. 1 as an example, assuming that the printing includes N color sets in total, wherein the first color set located upstream of the production line is used as a reference color set, and no measurement module is provided, then starting from the second color set, one measurement module is provided downstream of each color set, and the whole registration system has N-1 measurement modules in total.

As shown in fig. 1, each of the measurement modules 2 includes an image collector 21 for collecting a target image, a light source 22 for supplementing light for image collection, a delay trigger board 23 for triggering the image collector 21 and the light source 22, a sensor 24 for triggering the delay trigger board, and a processor 25 for calculating a register offset value, and the processor 25 in each measurement module 2 is electrically connected to the printer controller through the printer communication bus 4.

In this example, the printer controller is a controller that performs adjustment of the printing positions of the color groups according to the correction parameters, and the controller can control adjustment of the printing positions of all the color groups in any adjustment mode in the prior art, which is not discussed in detail in the solution of the present application.

Alternatively, the printer controller may be in communication with the processors via cables, or may be in communication via wireless means, such as a wireless local area network.

In this example, the delay trigger board 23 is electrically connected to the sensor 24, the processor 25, the image collector 21 and the light source 22, respectively, and the processor 25 is also electrically connected to the image collector 21, so that the delay trigger board 23 can generate a delay trigger signal for each device in the measurement module according to the trigger signal generated by the photoelectric target, that is, generate an image collection delay signal for the image collector, generate a light source delay signal for the light source, and send the signal to the corresponding device, and each device in the measurement module is triggered and started according to the corresponding trigger signal.

It should be further noted that, during the printing process, the set speed of the printing material is generally low, and the production speed is generally high, so that the speed from the set speed to the production speed needs to be increased, and the printing material needs to be decelerated after running out or reaching the printing length requirement, so that the printing tension changes, and further the printing material is deformed. It is understood that the amount can be positive or negative, i.e., the relative stretch amounts described herein can be either positive or negative; generally, if the substrate is stretched, the relative stretch amount is a positive value, and if the substrate is shortened, the relative stretch amount is a negative value.

It will be appreciated that the actual feed speed of the printing press is within a small fluctuation range even when the printing press is operated at the production speed, and controlling the feed speed process results in a slight acceleration or deceleration of the printing press, which also results in fluctuations in the tension deformation of the substrate, and therefore requires real-time measurement of the relative tension of the substrate.

The method for measuring the relative stretching amount of the printing material provided by the present application will be described below by taking the apparatus shown in fig. 1 as an example.

The scheme provided by the application is used for measuring the relative stretching amount of the printing material after paper feeding between any two color groups, so that the application considers two measurement modules to be measured as one stretching amount measurement group, the measurement module positioned at the upstream in each stretching amount measurement group is marked as a first measurement module, each device in the measurement module is correspondingly marked as a first device, the processed physical amount of the measurement module is marked as a first physical amount, the measurement module positioned at the downstream is marked as a second measurement module, each device in the measurement module is correspondingly marked as a second device, and the processed physical amount of the measurement module is marked as a second physical amount. It is understood that the two color sets to be measured may be adjacent or not adjacent, and if not specifically stated, the following examples are all described by taking the two color sets as adjacent examples.

Fig. 2 shows a schematic diagram of one plate-week target provided herein, as shown in fig. 2, each plate-week target comprising a photoelectric target, a calibration target, and a plurality of reference targets.

Fig. 3 shows a flowchart of a method for measuring relative stretching amount of a printing material according to the present application, and as shown in fig. 3, the method measures based on a time interval and a paper feeding speed, and specifically includes the following steps S101 to S106:

step S101, a first processor obtains a first time interval and sends the first time interval to a second processor, wherein the first time interval is a time interval when a first delay trigger board is triggered twice.

In this example, the time interval refers to a time interval in which the same color set is triggered in two plate periods, the two plate periods may be two adjacent plate periods or two non-adjacent plate periods, and how to select the time interval is specifically selected according to the measurement object, for example, if the relative stretching amount of the printing material between the two adjacent plate periods is calculated, the starting and ending times of the time interval are the times at which the color set is triggered in the two adjacent plate periods respectively, and if the relative stretching amount of the printing material between the first and third plate periods is calculated, the starting and ending times of the time interval are the times at which the color set is triggered in the first plate period and the third plate period respectively.

It will be appreciated that the relative stretch measurement ranges are application specific, for example, for register value correction, and that the relative stretch of the substrate between adjacent color groupings is typically measured to enable more timely and accurate adjustment of the register parameters. For another example, in a wind application to maintain a constant draw rate, to accurately measure the change in draw rate, the relative amount of stretch from the unwind end to the wind end is typically measured.

In this example, the first time interval is the difference between the times at which the first color set is triggered in the two to-be-tested plate cycles, and the difference can be obtained by the first processor and sent to the second processor.

Step S102, a second processor obtains a second time interval, wherein the second time interval is a time interval when a second time-delay trigger plate is triggered twice, and the plate cycle when the second time-delay trigger plate is triggered twice is the same as the plate cycle when the first time-delay trigger plate is triggered twice.

In this example, the manner of obtaining the second time interval is the same as the manner of obtaining the first time interval, and is not described herein again.

In particular, the start-stop time of the second time interval is obtained in the same cycle as the start-stop time of the first time interval. For example, if the first time interval is the time interval between the first color set first and second plate cycles, then the second time interval is the time interval between the second color set first and second plate cycles; if the first time interval is the time interval between the first and third plateaus of the first color set, then the second time interval is the time interval between the first and third plateaus of the second color set.

Step S103, the first processor obtains a first longitudinal deviation, and sends the first longitudinal deviation to the second processor, wherein the first longitudinal deviation is a longitudinal deviation between a geometric center of the first target image and a geometric center of a printed first target image.

In this example, the longitudinal direction refers to the direction along the paper feed. Based on this, it is understood that the longitudinal deviation means a deviation in the paper feeding direction.

In this implementable manner, the method of acquiring the first longitudinal deviation includes steps S131 to S133:

step S131, geometric center coordinates of the first target image are obtained.

In this example, the step may specifically include:

acquiring a first target image;

and determining the geometric center coordinates of the first target image.

The first target image is an image acquired by an image acquirer, the image carries a first target image, the first target image may be complete or incomplete, but with the increase of printing plate cycles, the color register parameters are continuously corrected, and the first target image is located at the center of the first target image more and more.

Further, the method for determining the geometric center coordinates of the first target image may be any method in the prior art, and the present application is not limited thereto.

Step S132, obtaining the geometric center coordinates of the first target image.

In this example, the step may specifically include:

determining a first target image;

and determining the geometric center coordinates of the first target image.

In this example, the method for identifying the first target image in the first target image is not particularly limited, and any method for identifying a specific target image in an image in the prior art may be used.

Further, the present example is illustrated using an annular or circular target, and any method known in the art for determining the geometric center of a geometric image may be used to determine the geometric center of the first target image and determine the coordinates of the geometric center of the first target image in the same coordinate system as the first target image.

It will be appreciated that even if the first target image is incomplete, its geometric center, which may be outside the first target image, may be determined by geometric means, but its coordinates are still determined in the aforementioned coordinate system.

Further, for target targets available in other shapes, the geometric center coordinates can also be determined using the same way as the example or an equivalent transformation.

Step S133, a first longitudinal deviation is calculated, where the first longitudinal deviation is a difference between a vertical coordinate of a geometric center of the first target image and a vertical coordinate of the geometric center of the first target image.

In this example, the first longitudinal deviation takes into account only the difference between the ordinates of the two geometric centres, and even if there is a difference in the transverse direction, it is not taken into account in this example.

And step S104, the second processor acquires a second longitudinal deviation, wherein the second longitudinal deviation is the longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor.

Similarly to the acquisition of the first longitudinal deviation, the method of acquiring the second longitudinal deviation may comprise the steps of:

acquiring a geometric center coordinate of a second target image;

acquiring geometric center coordinates of a second target image;

and calculating a second longitudinal deviation, wherein the second longitudinal deviation is the difference between the ordinate of the geometric center of the second target image and the ordinate of the geometric center of the second target image.

The implementation manner of each step is the same as that of each step corresponding to the calculation of the first longitudinal deviation, and is not described herein again.

In step S105, the second processor acquires the paper feed speed.

In this example, the paper feeding speed may be a preset value or may be actually measured, and the method for measuring the paper feeding speed may be any method for measuring the paper feeding speed of the printing press in the prior art, which is not particularly limited in this application.

And step S106, the second processor calculates the relative stretching amount of the printing material according to the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

In this example, this step can be specifically calculated according to the following formula (1):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁formula (1)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing the speed of paper feed, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

In this implementation, the measurement method may further include the following steps S107 to S110:

step S107, acquiring a first correction trigger distance N of the previous plate week₁And a second correction trigger distance N₂。

In this implementation, the first calibration trigger distance is a trigger distance theoretically calibrated based on the first actual trigger distance of the previous plate week based on the plate week for which the first calibration trigger distance is obtained, for example, if the relative stretching amount of the printing material between the fourth plate week and the fifth plate week is calculated this time, the first calibration trigger distance is the theoretical calibration amount added to the actual trigger distance between the third plate week and the fourth plate week, and the theoretical calibration amount is determined according to parameters such as the bias value, and therefore, the first calibration trigger distance is a theoretical value that is used as the current plate week, in this example, as an ideal value of the trigger distance between the fourth plate week and the fifth plate week.

Correspondingly, the second correction trigger distance is a trigger distance theoretically corrected on the basis of the second actual trigger distance of the previous version week based on the version week for which the second correction trigger distance is acquired.

Step S108, obtaining a first actual trigger distance M of the current edition week₁And a second actual trigger distance M₂。

The first actual trigger distance of this version is the measured value. Ideally, the first actual trigger distance is equal to the first corrected trigger distance.

It will be appreciated that the second actual trigger distance is similar to the first actual trigger distance.

In step S109, the first correction deviation and the second correction deviation are acquired.

In this example, the first correction offset is a first correction trigger distance N₁Distance M from the first actual trigger₁The difference between them.

Similarly, the second correction offset is a second correction trigger distance N₂And a second actual trigger distance M₂The difference between them.

Step S110, calculating the relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed.

This step can be specifically calculated according to the following formula (2):

Δl＝(Δt₂-Δt₁)×v+y₂-y₁+N₂-M₂+M₁-N₁formula (2)

Wherein, Deltal represents the relative stretching amount of the printing material, Deltat₁Representing a first time interval, Δ t₂Representing a second time interval, v representing a paper feedSpeed, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

Fig. 4 shows a flowchart of another method for measuring the relative stretching amount of the printing material provided by the present application, and as shown in fig. 4, the method measures based on the distance interval, and specifically includes the following steps S201 to S206:

step S201, a first processor obtains a first distance interval and sends the first distance interval to a second processor, wherein the first distance interval is a paper feeding distance of a printing material during two times of triggering of a first delay trigger board.

In this example, the acquisition timing is as described in step S101, and is not described herein again.

Further, the paper feeding distance may be measured by any method known in the art for measuring the paper feeding distance of the printing material in a specific time period, and the present application is not particularly limited.

Step S202, a second processor obtains a second distance interval, wherein the second distance interval is a paper feeding distance of a printing material during the period that a second time delay trigger plate is triggered twice, and the plate periphery of the second time delay trigger plate triggered twice is the same as the plate periphery of the first time delay trigger plate triggered twice.

The collecting timing of this step is as described in step S102, and is not described herein again.

Further, the paper-feeding distance is collected in the same manner as step S201 in order to reduce the systematic error.

Step S203, the first processor obtains a first longitudinal deviation, which is a longitudinal deviation between a geometric center of the first target image and a geometric center of the first target image printed by the first processor, and sends the first longitudinal deviation to the second processor.

The implementation manner of this step is the same as that of step S103, and is not described herein again.

In step S204, the second processor obtains a second longitudinal deviation, which is a longitudinal deviation between the geometric center of the second target image and the geometric center of the second target image printed by the second processor.

The implementation manner of this step is the same as that of step S104, and is not described herein again.

In step S205, the second processor acquires the paper feed speed.

The implementation manner of this step is the same as that of step S105, and is not described herein again.

In step S206, the second processor calculates a relative stretch amount of the printing material according to the first distance interval, the second distance interval, the first longitudinal deviation, the second longitudinal deviation, and the paper feeding speed.

In this implementation, calculating the print material relative stretch amount based on the first distance interval, the second distance interval, the first longitudinal deviation, the second longitudinal deviation, and the paper feed speed may specifically be calculated according to the following formula (3):

Δl＝ΔL₂-ΔL₁+y₂-y₁formula (3)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Indicating a second longitudinal deviation.

Further, the method of acquiring the first longitudinal deviation and the second longitudinal deviation is the same as the method of acquiring the corresponding longitudinal deviation in the previous implementation.

In this implementation, the measurement method may further include step S207 to step S210:

step S207, acquiring a first correction trigger distance and a second correction trigger distance of the previous version week;

step S208, acquiring a first actual trigger distance and a second actual trigger distance of the current edition cycle;

step S209, acquiring a first correction offset and a second correction offset;

step S210, calculating a relative stretching amount of the printing material according to the first correction deviation, the second correction deviation, the first time interval, the second time interval, the first longitudinal deviation, the second longitudinal deviation and the paper feeding speed, which can be specifically calculated according to the following formula (4):

Δl＝ΔL₂-ΔL₁+y₂-y₁+N₂-M₂+M₁-N₁formula (4)

Wherein, DeltaL represents the relative stretching amount of the printing material, DeltaL₁Denotes the first distance interval, Δ L₂Denotes a second distance interval, y₁Denotes the first longitudinal deviation, y₂Representing a second longitudinal deviation, N₁Denotes a first calibration trigger distance, M₁Representing a first actual trigger distance, N₂Indicating a second correction trigger distance, M₂Representing a second actual trigger distance.

In this example, steps S207 to S209 correspond to steps S107 to S109, respectively, and are not described again.

The present application also provides a program for measuring a relative stretch amount of a printing material, the program being configured to implement the steps of the method for measuring a relative stretch amount of a printing material according to the first aspect.

The present application also provides a computer readable storage medium, on which computer instructions are stored, and the instructions, when executed by a processor, implement the steps of the method for measuring the relative stretching amount of the printing material according to the first aspect.

The present application further provides a detection apparatus, the detection apparatus includes: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the processor, and the instructions are executed by the at least one processor to cause the at least one processor to perform the method for measuring relative stretching of the printing material according to the first aspect.

The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.