CN113561646A - Registration system and printing equipment - Google Patents

Abstract

The application provides a registration system, which is suitable for registration control of a plurality of color groups, wherein each color group is provided with a registration module, and each registration module can be combined with deformation of a printing material to independently determine image acquisition time, so that accumulated errors of photographing time are eliminated, and correct targets are acquired under the condition of a small visual field; every register module only is used for detecting its cover bias value that corresponds the relative benchmark look group of colour group, consequently, the register adjustment of all look groups is independent each other, avoids all adjusting thereupon because of adjusting the parameter of a certain colour group or several colour groups and leads to follow-up look group parameter, and, register system is high to the detection precision of all look group cover bias values, and response speed is fast, every register module all disposes embedded treater among the register system, does not set up unified industrial computer to improve the processing speed, reduce communication delay, make the register precision of printed matter high, be applicable to multiple printing scenes such as flexo printing, gravure and digital printing.

Description

Registration system and printing equipment

Technical Field

The application belongs to the field of printing equipment, and particularly relates to a registration system and printing equipment.

Background

On a multi-color set printing device, a color complex pattern is generally formed by overlapping and printing a plurality of color sets at the same position, and in a trial stage, the process of ensuring the accurate overlapping and the accurate overlapping of the color sets at the same position is called as registration. The existing multi-color-set printing equipment comprises a plurality of color sets with different colors and a registration module, wherein each color set uses the same target and the same registration module to realize registration measurement and control, and if parameters such as trigger time or distance of one color set are adjusted, corresponding parameters of all the color sets need to be adjusted accordingly.

The registration scheme comprises three types of manual registration, photoelectric registration and visual registration. The manual registration scheme is where the printer operator views a target in a still picture, typically a cross target as shown in figure 1 a. The equipment used in the photoelectric registration scheme comprises a central processing unit and a plurality of color mark sensors, wherein each color group corresponds to one color mark sensor, the central processing unit is communicated with each color mark sensor through a signal bus, a registration deviation value is obtained by acquiring the trigger interval and the trigger time of the color mark sensors when printing targets of different color groups pass through, the registration deviation value is fed back to the printing machine, the printing machine continuously corrects the trigger time length according to the registration deviation value to realize automatic registration, the targets used in the photoelectric registration scheme are generally designed into a rectangle, a triangle or a trapezoid and the like for triggering the color mark sensors, and the photoelectric registration target shown in figure 1b is trapezoidal. The system generally comprises a central processing unit and an image collector, wherein an image collected by the image collector comprises all color codes on a single-page printed matter, a target area is formed by shooting a reference color group and any color group and printing at the same position in sequence, the printing characteristics of different color groups are extracted by a machine vision method, and pattern fitting is carried out to obtain a register offset value. To improve the fitting accuracy, the target for visual registration is typically designed as a concentric ring, as shown in FIG. 1 c.

High quality fine prints generally require higher registration accuracy, and prior art registration solutions have difficulty meeting such high quality printing requirements. Specifically, in the manual registration scheme, an operator manually adjusts the phase deviation of each color group according to the width of the cross stroke, the registration mode is completely carried out according to human eyes, the adjustment time is long, the efficiency is low, the material waste in the machine adjusting stage is serious, and the final adjustment precision cannot be guaranteed. The photoelectric registration scheme is limited by the low accuracy of the color mark sensor, cannot meet the high accuracy requirement of high-end printed products, and particularly has a large error range when printing materials with large stretching coefficients, and cannot ensure the registration accuracy. The vision scheme is limited by the fact that the image acquisition device needs an imaging surface to be a plane, however, the printing point is an arc surface, and therefore the image acquisition device needs to be arranged at the downstream position of the printing point, namely, a certain distance exists between the installation position of the image acquisition device and the printing point, which can lead to the lagging of the offset value data, especially in the acceleration and deceleration process of the printing machine, the printing tension is easy to change, which leads to the deformation of a printing substrate, and further leads to the incapability of maintaining the alignment precision.

Disclosure of Invention

For solving the problem that prior art exists, this application provides a registration system and uses registration system's lithography apparatus, registration system includes a plurality of colour groups, and every colour group disposes a registration module, and every registration module can independently confirm target registration target image acquisition opportunity according to the printing material deformation to eliminate the accumulative error at image acquisition opportunity, guarantee still can gather correct target registration target image under the little field of view condition. Each registration module is used for detecting the registration deviation value of the corresponding specific color set relative to the reference color set, so that the adjustment of the registration parameters of each color set in the registration system is independent, the subsequent adjustment of the color set parameters caused by the adjustment of the parameters of one or more color sets is avoided, and each registration module in the registration system is respectively provided with an embedded processor without a uniform industrial personal computer, thereby improving the processing speed and reducing the communication delay. Furthermore, the registration system has high detection precision on the registration offset values of all color groups and high response speed, so that the registration precision of printed matters is high, and the registration system is suitable for various printing scenes such as flexography, gravure printing, digital printing and the like.

The aim of the present application is to provide a registration system, applied to a multi-color set printing machine, the multi-colour-set printer comprises a plurality of colour-sets 1 and a printer controller, the registration system comprises a plurality of registration modules 2, the number of registration modules 2 is equal to the number of colour-sets 1, a registration module 2 is arranged downstream of each color set 1, the registration module 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 color scale sensor 24 for triggering the delay trigger board, and an embedded processor 25 for calculating a registration deviation value, the embedded processor 25 in each registration module 2 is electrically connected to the printer controller through a printer communication bus 3, and the registration system is configured to execute the following procedures:

the color code sensor triggers the delay trigger board after identifying the photoelectric target;

the delay trigger board triggers the image collector according to preset delay time;

the image collector collects a registration target image, and the registration target image comprises a reference color set and a target color set which are nested;

the embedded processor calculates the registration deviation value of the target color set relative to the reference color set according to the received registration target image;

and the embedded processor sends the calculated deviation value to a printer controller.

Every colour group disposes a registration module in the registration system that this application provided, the registration module only carries out the registration for the only colour group appointed and detects, and the detection of every colour group cover partial value is mutually independent, and, every the registration module is next to with the colour group that corresponds to can detect the cover partial value of this colour group immediately after the printing of each colour group is accomplished, and not only detection efficiency is higher, and the degree of accuracy of the cover partial value that detects is also higher.

In an implementation manner, the delay trigger board 23 is electrically connected to the color patch sensor 24, the embedded processor 25, the image collector 21 and the light source 22, respectively, and the embedded processor 25 is also electrically connected to the image collector 21.

Optionally, the time length of the time delay of the image collector 21 by the time delay trigger plate 23 is set according to the distance between the color patch sensor 24 and the image collector 21 and the paper feeding speed, and specifically, may be the quotient of the distance between the color patch sensor 24 and the image collector 21 and the paper feeding speed.

Optionally, the color patch sensor 24 is disposed upstream of the image collector 21.

In the present application, the image collector 21 is configured to collect a registration target image, which is an image including a registration target.

Further, the registration targets in each registration target image are different.

Optionally, the field of view of the image collector 21 is slightly larger than the registration target, and the registration target is a target for calculating a registration deviation value, so that the proportion of the registration target in the registration target image is as large as possible, and the registration target image can accommodate an acceptable registration deviation, so that the registration target in the registration target image is as complete as possible, and the calculation of the registration deviation value is facilitated.

In an implementation manner, the light source 22 is an annular light source and is distributed around the lens of the image collector 21, so that light is supplemented during the image collection process, and the provided light is uniform, so that the collected registered target image is clearer and more accurate, and further, the calculation of the registration deviation value is more accurate.

Further, the embedded processor 25 is configured to calculate a misregistration value from the received registration target image.

Furthermore, the embedded processor 25 is further configured to calculate a color register parameter correction value according to the color register deviation value, so as to continuously correct the color register parameters of the color set, so that the color register deviation value of the obtained printed product is within a preset range, and obtain a high-quality printed product.

Optionally, the embedded processor 25, the delay trigger board 23, the image collector 21, the light source 22, and the color scale sensor 24 are packaged in a housing, so as to facilitate maintenance of the registration module, and a sensor window for exposing the color scale sensor 24 and a collector window for exposing the image collector 21 are opened on the housing.

Further, the light emitted by the light source 22 can pass through the collector window and irradiate the surface of the printed matter, so that the light emitted by the light source 22 can irradiate the printed base material without being shielded by the housing.

In one implementation, the registration system is further configured to perform the following procedure:

the embedded processor calculates the color register parameter correction value of the color register module corresponding to the color set according to the color register deviation value;

and correcting the color register parameters of the corresponding color groups according to the color register parameter correction values.

In an implementation manner, the registration system continues to perform the color process deviation value detection after modifying the color process parameters, and generates the color process parameter correction value again according to the newly generated color process deviation value, and repeats the above two steps continuously until the color process deviation value reaches the preset range, and the color process parameters corresponding to the color set are determined as the current parameters.

Further, after the color register parameters of all color groups are determined, the machine testing stage is completed.

The application also provides a printing device applying the registration system, which is characterized by comprising a plurality of color groups, and a color registration module is arranged at the downstream of each color group.

Compared with the prior art, the registration target graph used by the registration system provided by the application is specially designed, and specifically comprises a color block used for triggering a color mark sensor, a correction target used for correcting the installation angle of an image collector and a double-ring target used for registration measurement, and the distance between the registration targets is a preset value. And the color mark sensor sends a trigger signal to the delay trigger plate after identifying the color block, and the delay trigger plate starts the image collector after specific delay, so that the trigger time of the image collector can be accurately and stably controlled, the field range of the image collector can be reduced, the resolution of the obtained registration target image is improved, and the measurement precision of the registration deviation value is improved. And, owing to use the photoelectric target to trigger the image collector, consequently, the opportunity of gathering the image can realize real-time adjustment, compares in the scheme of fixed acquisition time or distance interval image acquisition, and the scheme that this application provided can eliminate accumulative error, guarantees to gather correct target registration target at every turn.

Further, the scheme provided by the application is used for performing modular design on color groups, each color group is combined with one color register module to form an independent printing subsystem, the register system is formed by freely combining a plurality of printing subsystems, the number of the printing subsystems can be flexibly configured according to the number of the color groups, redundant printing subsystems are not required to be arranged, all the printing subsystems are configured as required under any printing task, no idle printing subsystems are required, equipment cost is reduced, each color register module only provides a color register value detection service for a unique color group, and the color register deviation of the color group is detected immediately after a register target of a specific color group is generated, namely, the color register value of each color group is printed and detected, and printing and tuning efficiency is improved. In addition, the chromatography system provided by the application adopts a distributed scheme, the architecture is clear, and the maintainability is greatly improved; furthermore, the color register system provided by the application combines the advantages of photoelectric registration and visual registration, so that the application range of a printing material is increased, and particularly, the register measurement precision and the register control precision of an easily-stretched material are greatly improved.

Drawings

FIG. 1a shows a cross target commonly used in manual registration protocols;

FIG. 1b shows a trapezoidal target used in the photoelectric registration scheme;

FIG. 1c shows a concentric point ring target for use in a visual registration protocol;

FIG. 2 illustrates a schematic of a conventional printing system;

FIG. 3 shows a schematic structural diagram of a registration system provided herein;

FIG. 4 shows a schematic representation of a preferred registration target of the present application;

fig. 5 shows a package structure diagram of a color register module provided in the present application.

Description of the reference numerals

10-color register subsystem, 1-color group, 11-plate cylinder, 12-impression cylinder, 13-guide cylinder, 2-registration module, 21-image collector, 22-light source, 23-time delay trigger plate, 24-color mark sensor, 25-embedded processor, 3-printing machine communication bus, 41-reference target, 42-target, 43-calibration color mark, 5-shell, 51-sensor window and 52-collector window.

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 registration system provided by the present application is described in detail below with specific examples.

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

Fig. 2 shows a schematic structural diagram of a conventional printing apparatus using visual color register, as shown in fig. 2, the conventional printing apparatus includes an industrial personal computer, a color register module, a plurality of color sets and a printer controller, wherein the printer controller is respectively communicated with the industrial personal computer and all the color sets, the printing apparatus includes a unique color register module and a plurality of color sets, the number of the color sets is determined and cannot be changed, no matter how the color sets are needed by a printed matter, the number of the color sets in the printing apparatus cannot be changed, the color sets which are not needed in a printing task are in an idle state in the whole printing process, the color register module serves all the color sets, the color register module is disposed at the downstream of all the color sets, an image collector collects a target image after all the color sets are printed, the target image includes a target generated by all the color sets, that is, one target image comprises a plurality of targets, the image collector sends the target image to an industrial personal computer, and the industrial personal computer calculates the color register value of each color group by using information such as the positions of the targets and the like, and then adjusts the color register parameters of each color group according to the color register value. In the above scheme, the image collector collects images at preset time intervals, if the printed substrate is deformed greatly, the targets of some color sets may exceed the image range, and in order to make the targets of all color sets completely included in the image, the view field of the image collector is generally enlarged, which in turn causes the occupation ratio of each target in the image to be small, and further causes inaccurate calculation of the misregistration value. In addition, the distance between the position where the registration deviation is formed and the measurement position is too far, so that the feedback time of the registration deviation value is long, the registration deviation value cannot be monitored in real time, and the registration deviation control precision is poor.

For the printing process, the printing equipment is required to be debugged before formal batch printing of the printed matter of the printing equipment so as to maximize the precision of the printed matter, thereby improving the quality of the printed matter, and the debugging comprises the calibration of mutual registration of all color groups, so that the deviation of all color groups is avoided, and the relative dislocation of all colors in the printing pattern is generated.

The registration system that this application provided is arranged in quick chromatography adjustment and the chromatography precision of normal printing in-process of unit formula printing machine at the examination machine stage to keep, and specially adapted film printed matter's chromatography control, film printed matter is the printed matter that carries out chromatography printing on the film substrate and obtains, the film substrate includes paper, plastic film or cloth etc.. Generally, a process printing apparatus forms a printing position into a curved surface by a plurality of consecutive cylinders, thereby improving printing accuracy. The registration method provided by the application is suitable for correcting the registration deviation in the debugging stage, and batch printing can be performed according to corrected registration parameters after the registration deviation values of all color groups meet preset conditions.

Another traditional printing device adopting visual color register in the prior art comprises an industrial personal computer, a plurality of cameras, a plurality of color groups and a printer controller, wherein each color group is provided with one camera, all the cameras are connected to the same industrial personal computer, the industrial personal computer presets photographing opportunities for all the cameras, processes target images, and collects and sends a register deviation value to the printer controller. In the scheme, the industrial personal computer does not have the stretching deformation information of the printing material, so that the accumulated error can be introduced by the shooting time control, and the registration measurement target cannot be accurately shot in long-time working. In addition, one industrial personal computer is adopted to process images of a plurality of cameras, the processing speed becomes slow, the misalignment result cannot be fed back quickly, and the registration control precision is reduced. In addition, if one camera fails, the cameras need to be reconfigured on the industrial personal computer after the camera is replaced, so that the system interchangeability is poor, and the maintainability is poor.

Fig. 3 shows a schematic diagram of a printing apparatus including a registration system provided in the present application, as shown in fig. 3, the registration system is applied to a multi-color set printing press shown in fig. 3, the multi-color set printing press includes a plurality of color sets 1, the registration system includes a plurality of registration modules 2, the number of the registration modules 2 is equal to the number of the color sets 1, one registration module 2 is arranged downstream of each color set 1, and each color set 1 and its corresponding registration module 2 form a registration subsystem 10.

In this example, each color registering subsystem 10 includes only one color set and only one registration module matching with the color set, that is, the registration module performs registration detection only for the assigned unique color set, detection of the color set registration deviation values of each color set is independent, and each registration module is adjacent to the corresponding color set, so that the registration deviation value of each color set can be detected immediately after printing of the color set is completed, and not only is detection efficiency higher, but also accuracy of the detected registration deviation value is higher.

As shown in fig. 3, 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 registration module 2 is disposed downstream of the downstream guide cylinder 13.

Taking the printing apparatus shown in fig. 3 as an example, assuming that the printing includes N color sets in total, wherein the first color set located at the upstream of the production line is used as a reference color set, and no color register module is provided, then starting from the second color set, one color register module is provided at the downstream of each color set, and the whole registration system has N-1 color register modules in total.

As shown in fig. 2, each of the registration 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 plate 23 for triggering the image collector 21 and the light source 22, a color scale sensor 24 for triggering the delay trigger plate, and an embedded processor 25 for calculating a registration deviation value, where the embedded processor 25 in each registration module 2 is electrically connected to the printer controller through the printer communication bus 3.

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 each embedded processor via a cable, 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 color scale sensor 24, the embedded processor 25, the image collector 21 and the light source 22, and the embedded 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 color register 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 light source delay signal to the corresponding device, and each device in the color register module is triggered and started according to the corresponding trigger signal.

Optionally, the delay time of the image acquirer 21 by the delay trigger board 23 is set according to the distance between the color patch sensor 24 and the image acquirer 21 and the paper feeding speed, and specifically, the delay time may be a quotient of the distance between the color patch sensor 24 and the image acquirer 21 and the paper feeding speed, so that the image acquirer 21 can acquire a complete target registration target exactly, thereby providing an accurate basis for a subsequent calculation of the registration deviation value.

According to the scheme provided by the application, the image collector 21 in each color register module can collect images according to the indication of the delay trigger plate 23, and can independently adjust the delay trigger parameters at any time according to the collected target images, so that the collected target images are complete.

Moreover, the image acquisition devices in the color registering modules only serve a single color group, so the field range of the color registering modules can be reduced, the resolution of the obtained registered target image is higher under the same acquisition condition, and the measurement precision is improved.

In contrast, the printing apparatus in the prior art does not have a trigger target or a delay trigger plate, and generally collects images of the registration targets after printing of all the color sets of registration targets according to a preset time interval, and the collected images of the registration targets include the registration targets of all the color sets.

Further, in the prior art, in order to avoid missing color groups in the registered target image, the shooting interval is usually reduced, or a continuous shooting mode is adopted in each shooting, and the field of view of the image acquisition device is even further enlarged.

As can be understood by those skilled in the art, shooting redundancy is generated by reducing shooting intervals or adopting a continuous shooting mode, and the calculation efficiency is reduced by firstly screening from redundant images and then calculating the set deviation values of each color set; the expansion of the field range of the image acquisition device can reduce the proportion of the target images of all color groups in the whole image, and has low resolution and poor measurement precision, so that the misregistration value is calculated inaccurately, the color register parameter is corrected inaccurately, and the requirement of the misregistration value of a high-precision printed product is difficult to meet; moreover, after the printing task is changed and the printing plate is changed, the color code position needs to be searched again, and the operation is complex and time-consuming.

In conventional printing apparatuses, some may be provided with photosensors for detecting the misregistration value, but the principle of calculating the misregistration value by the photosensors may result in low misregistration value accuracy.

The color mark sensor 24 may use a photoelectric sensor, but, instead of detecting the misregistration value, the photoelectric sensor is used as a position sensor to generate a trigger signal, that is, a photoelectric target is printed at a preset position of a to-be-detected printed matter, and as the printed matter is continuously fed, the photoelectric target continuously approaches the color mark sensor 24 until the printed matter passes through the color mark sensor 24, the color mark sensor 24 generates a trigger signal after detecting the photoelectric target passing through the color mark sensor, and sends the trigger signal to the time delay trigger board 23, and the time delay trigger board 23 sends a corresponding trigger signal to a corresponding device in the color register module after receiving the start information.

In this example, the color patch sensor 24 may be disposed upstream of the image collector 21, that is, the printed product passes through the color patch sensor 24 first and then passes through the image collector, so that the time delay trigger board 23 controls the trigger timing.

Alternatively, the color patch sensor 24 may be disposed downstream of the image collector 21, that is, the printed product passes through the image collector 21 and then passes through the color patch sensor 24. This case still allows accurate triggering because the printing plate has a fixed period, and thus the shooting delay increases by one plate period, and the next plate is shot with a double loop target pattern.

In the present application, the image collector 21 is configured to collect a registration target image, which is an image including a registration target.

In this example, since the field of view of the image pickup device 21 is small and the object to be measured has symmetry, the image pickup device 21 does not need to perform distortion correction. Specifically, the parameters of the image collector 21 make the following assumptions: the lens distortion is 0.5%, the diagonal length of the field of view is 4mm, the diagonal pixel length is 1800, the resolution is 0.015, if the misalignment value is less than 1mm, the maximum measurement deviation which can be caused is 0.5% × (4mm/0.015mm)/1800 × 1mm/2<0.001mm, and the distortion correction is not needed.

Fig. 4 shows a schematic diagram of a preferred registration target of the present application, as shown in fig. 3, the registration target includes a reference target 41 and a target 42, the reference target 41 and the target 42 may be both circular rings, and in each set of registration targets, the reference target 41 is disposed inside the target 42, and the colors of the reference target 41 and the target 42 may be different.

In the present application, the registration targets may be distributed in multiple rows, or may be distributed in any position that does not affect the effect of the final printed product, such as die cutting, gluing, etc., so as to reduce the edge material loss of the printing material, or to adapt to short printing plate.

In this example, a color patch for triggering the color patch sensor 24 is disposed upstream of the registration target, and the color patch may be in any shape available in the art for triggering color patch sensors, such as a rectangle, etc.

In the present example, the target 42 is concentric with the reference target 41 in the ideal case, i.e. if no misregistration of the colour sets occurs.

Further, a calibration color scale 43 for calibrating the error of the image collector 21 is further disposed between the trigger color scale and the first reference target, and the shape of the calibration color scale 43 may be any color scale capable of calibrating the error of the image collector in the prior art, for example, a cross-shaped color scale.

In this example, the field of view of the image collector 21 may be 200% of the outer diameter of the registration target, so that the image collector 21 can accommodate the deformation of the printing substrate and maximize the ratio of the reference target to the target in the obtained registration target image.

It will be appreciated that the relative positions and colours of the registered targets generated by each colour set are different.

Optionally, the field of view of the image collector 21 is slightly larger than the registration target, and the registration target is a target for calculating a registration deviation value, so that the ratio of the registration target in the registration target image is as large as possible, and at the same time, in the case of a film-like substrate with a large deformation due to a large stretching coefficient, the image can still include the complete registration target.

The image collector 21 in the color registering module provided by the application does not automatically collect images according to a preset time interval, but is triggered by the delay trigger plate 23, so that the starting time of the image collector 21 is more accurate, the collected images contain complete registration targets, each image only comprises one specific registration target but not other targets, the occupation ratio of the registration targets in the images is large, and further compared with the traditional scheme, the accuracy of the calculated registration deviation value according to the images is higher.

In this example, the light source 22 is an annular light source and is uniformly distributed around the lens of the image collector 21, so that light is uniformly supplemented in the process of collecting the image, a clearer and more accurate registered target image is obtained, and the registration deviation value is calculated more accurately.

Further, the embedded processor 25 is configured to calculate a misregistration value from the received registration target image.

Furthermore, the embedded processor 25 is further configured to calculate a color register parameter correction value according to the color register deviation value, so as to continuously correct the color register parameters of the color set, so that the color register deviation value of the obtained printed product is within a preset range, and obtain a high-quality printed product.

Optionally, the embedded processor 25, the delay trigger board 23, the image collector 21, the light source 22, and the color scale sensor 24 are packaged in a housing, so as to facilitate maintenance of the registration module, and a sensor window for exposing the color scale sensor 24 and a collector window for exposing the image collector 21 are opened on the housing.

Further, the light emitted by the light source 22 can pass through the collector window and irradiate the surface of the printed matter, so that the light emitted by the light source 22 can irradiate the printed base material without being shielded by the housing.

Fig. 5 shows a packaging structure diagram of a color register module provided in the present application, as shown in fig. 5, the color register module may further include a housing 5, and each device in the color register module is packaged in the housing 5, that is, the embedded processor 25, the delay trigger board 23, the image collector 21, the light source 22, and the color patch sensor 24 are all packaged in the housing 5, and a sensor window 51 for exposing the color patch sensor 24 and a collector window 52 for exposing the image collector 21 are opened on the housing.

In this example, the term "exposed" means that a device enclosed in a housing can penetrate a window to collect a signal, and a corresponding device can extend out of the housing, can be flush with the housing, and can even be installed in the housing, for example, the outer end of the lens of the image collector can be flush with the outer edge of the collector window, can extend out of the housing through the collector window, and can even remain in the housing, but the lens can collect an image of a registered target through the collector window.

Further, in this example, the light source 22 is disposed around the lens of the image collector, so that the light source is also exposed out of the collector window, so that the light emitted by the light source 22 can be irradiated onto the surface of the printed matter through the collector window, thereby providing illumination for the image collector during the image collection process.

Furthermore, the opening positions of the sensor window and the collector window can be specifically set according to the collection requirement, for example, the sensor window and the collector window can be arranged on the same shell wall or on different shell walls respectively, but the sensor window is always kept at the upstream of the collector window in the use process.

Furthermore, the positions of the other components of the color register module except the color mark sensor 24, the image collector 21 and the light source 22 in the housing are not particularly limited, and may be set at any position of the inner cavity of the housing, so that the overall size of the color register module is small, and the color register module is convenient to install and use in a printing system.

In this example, the registration system is configured to execute a program comprising:

and S101, triggering a delay trigger board after the color scale sensor identifies the photoelectric target.

In the system provided by the present application, the acquisition object of the image acquirer 21 is a registered target that has already been printed, so that before the printing substrate is conveyed to the color scale sensor, the printing substrate sequentially passes through the reference color set and prints the reference target at a preset position, and after the printing substrate is conveyed to the corresponding color set, the printing substrate prints the target targets, and each reference target and the target form a set of registered targets.

It will be appreciated that the reference targets are grouped in sets of a number equal to the number of colour groups and that each set will print in each plate cycle.

The length occupied by each group of reference targets is related to the interval of the reference targets and the number of the reference targets, specifically, assuming that the number of color groups is N, the number of the patterns (including the photoelectric targets and the reference targets) is N +1, and assuming that the interval between adjacent patterns is 20mm and the width of the patterns is 4mm, the length occupied by each group of reference targets is (N × 20+4) mm.

After each color set finishes corresponding color register, the photoelectric target is firstly transmitted to the color scale sensor 24, and the color scale sensor 24 sends a trigger signal to the delay trigger plate 23 after acquiring a signal of the photoelectric target.

In this example, the color scale sensor 24 does not directly send the start signal to the devices in the color register module, so that the devices in the color register module can be triggered at the preset time, rather than being triggered immediately, thereby accurately controlling the time at which the devices are triggered, and enabling the jobs between the color register modules to be distinguished from each other, so as to implement independent jobs.

And S102, triggering the image collector by the delay trigger board according to preset delay time.

In this example, the parameters set by the delay trigger boards in the color registering modules are different, for example, the preset delay durations set by the delay trigger boards are different, so that the corresponding registering targets can be accurately captured in the color registering modules.

In this example, the delay time may be directly based on the dot information generated by the encoder mounted on the printing material, or may be based on the printing speed information of the printer.

The determination of the delay time period is explained below by taking the printing speed information using the printing press as an example:

time-delay shooting distance/paper feeding speed

Wherein, the time-delay shooting distance is equal to the distance L between the color block and the target₁+ color scale sensor distance from camera L₂；

Wherein, for different chromatography modules, L₁Different from each other, and L₂The paper feeding distance from the color mark sensor triggering position to the camera photographing position is fixed.

It will be appreciated that if the photoelectric target passes through the image collector first and then the color scale sensor, then L₂Take a negative value, further, if L₁+L₂If the value is negative, the delayed shooting distance is increased by 1 or more plate circumferences.

S103, the image collector collects a registration target image, and the registration target image comprises a reference color set and a target color set which are overlapped.

In this example, once the image collector is triggered, periodic photographing may be performed according to a preset time interval, or a trigger signal of each version is waited to obtain a registered target image of the target color set, and the color register parameter is updated according to each registered target image by continuously updating the color register value.

And S104, calculating the color deviation value of the target color set relative to the reference color set by the embedded processor according to the received registered target image.

In this example, the registered target image collected by the image collector is processed in the color register module, and the color register value of the color set is calculated.

In this example, after acquiring the registration target image, the image acquirer 21 sends the registration target image to the embedded processor 25, and after receiving the registration target image, the embedded processor 25 calculates the color-register value of the color set according to a pre-built processing program of the embedded processor 25, and generates the color-register parameter correction value, and further, the embedded processor 25 sends the color-register parameter correction value to the corresponding color set.

The color register correction value parameter can be fused with the result of the stretching amount of the printing material before being sent to the printing machine controller, and can also be sent to the printing machine controller by the registration correction value and the result of the stretching amount of the material, and the printing machine is controlled after self-fusion.

In this example, the method for calculating the casing deviation value may:

the collected target image comprises a large ring and a small ring which are sleeved together, the edges of the large ring and the small ring are respectively identified, and circle fitting is carried out to obtain the circle centers of the two rings. And obtaining the deviation value of the paper feeding direction and the paper feeding direction perpendicular to the paper feeding direction according to the distance between the circle centers of the two circular rings and the position relation.

In this example, the registration system is further configured to perform the following procedure:

the embedded processor calculates the color register parameter correction value of the color register module corresponding to the color set according to the color register deviation value;

and correcting the color register parameters of the corresponding color groups according to the color register parameter correction values.

Further, the color set receiving the color register parameter correction value adjusts the color register parameter according to the received color register parameter correction value, so that the color register offset value meets the preset range.

It can be understood that the process parameters may need to be processed through multiple rounds of the above processes to enable the color process deviation value to meet the preset range, that is, the registration system continues to perform the detection of the color process deviation value after modifying the color process parameters, and generates the color process parameter correction value again according to the newly generated color process deviation value, and repeats the above two steps continuously until the color process deviation value reaches the preset range, and the color process parameter corresponding to the color set is determined as the current parameter.

Further, after the color register parameters of all color groups are determined, the machine testing stage is completed.

Compared with the prior art, aiming at the defects of the existing photoelectric scheme and the existing visual scheme, the registration system provided by the application combines the photoelectric and visual registration schemes, utilizes the measurement timeliness of the photoelectric scheme and the measurement high-precision characteristic of the visual scheme, and carries out modular design on the multicolor group registration measurement system, thereby ensuring the overprinting precision of all color groups in the whole printing process; specifically, the registration system provided by the application uses the color scale sensor to trigger and start the image collector, so that the image collector can be accurately and stably triggered, the field range of the image collector can be reduced, the resolution of the obtained registration target image is improved, and the measurement precision of the registration deviation value is improved; moreover, the registration system provided by the application is not provided with a central processing unit or a central transmission bus, all color registering subsystems are connected in parallel and can work independently, each color registering module calculates the register deviation value of the reference color set and the unique specific color set and adjusts the color registering parameters of the corresponding color sets, namely, the color registering parameters corresponding to each module are only responsible for the unique color set, the register deviation values of all color sets are relatively independent and do not interfere with each other, and the color registering parameters of a specific color set can be adjusted in a targeted manner, so that the problem that the traditional color registering scheme causes the accumulated error caused by the register deviation of the adjacent color sets before and after measurement and the adjustment of the front color set can cause the follow-up adjustment of the rear color set is avoided.

In addition, in the registration system that this application provided, every color register module is a module that possesses complete function, the external interface only takes a picture parameter control, the printing machine speed obtains and the processing result output, can be according to the nimble configuration of look group quantity, a plurality of look groups realize the cooperation with the distributed mode, maintainability has been strengthened, and, the quantity of color register module corresponds with the quantity of look group, can calculate the cover bias value and the color register parameter correction value of this look group immediately after gathering the registration image of accomplishing a look group, and in time feed back to corresponding look group, the simultaneous registration of all look groups is accomplished in coordination to each color register module, and need not to wait to calculate the cover bias value of each look group again in unison after all printing of all look group targets are accomplished, therefore, the color register module that this application provided is chromatic precision height, the correction rate is fast.

Furthermore, the color register module provided by the application takes the signal collected by the color mark sensor as a trigger signal, so that the image collected by the image collector with the visual field range being only larger than that of a single registration target can just capture the registration target, thereby reducing the visual field of the camera, improving the resolution ratio and further ensuring that the calculation of the registration deviation value is more accurate. Meanwhile, due to the fact that the scheme of adjusting the photographing time triggered by the color block in real time is used, compared with the scheme of photographing at fixed time or distance intervals, accumulated errors can be eliminated, and a correct target can be photographed each time.

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.

Claims (10)

1. A registration system, characterized in that, the registration system is applied to a multi-color set printing machine, the multi-color set printing machine includes a plurality of color sets (1) and a printing machine controller, the registration system includes a plurality of registration modules (2), the number of the registration modules (2) is equal to the number of the color sets (1), one registration module (2) is configured at the downstream of each color set (1), the registration module (2) includes an image collector (21) for collecting a target image, a light source (22) for supplementing light for image collection, a time delay trigger board (23) for triggering the image collector (21) and the light source (22), a color scale sensor (24) for triggering the time delay trigger board and an embedded processor (25) for calculating a registration deviation value, the embedded processor (25) in each registration module (2) is electrically connected with the printing machine controller, wherein the registration system is configured to perform the following procedures:

the color code sensor triggers the delay trigger board after identifying the photoelectric target;

the delay trigger board triggers the image collector according to preset delay time;

the image collector collects a registration target image, and the registration target image comprises a reference target image and a target image which are overlapped;

the embedded processor calculates the registration deviation value of the target color set relative to the reference color set according to the received registration target image;

and the embedded processor sends the calculated deviation value to a printer controller.

2. The registration system of claim 1, wherein each color set in the registration system is configured with one registration module, wherein the registration module performs registration detection only for the assigned unique color set, wherein detection of the color set registration bias values is independent of each other, and wherein each registration module is in close proximity to the corresponding color set.

3. The registration system according to claim 1 or 2, wherein the time-delay trigger board (23) is electrically connected with the color patch sensor (24), the embedded processor (25), the image collector (21) and the light source (22), respectively, and the embedded processor (25) is also electrically connected with the image collector (21).

4. The registration system according to any of claims 1 to 3, wherein the delay time of the image collector (21) by the delay trigger board (23) is set according to the distance between the color patch sensor (24) and the image collector (21) and the paper feeding speed, in particular, the quotient of the distance between the color patch sensor (24) and the image collector (21) and the paper feeding speed.

5. The registration system according to any of claims 1 to 4, wherein the field of view of the image collector (21) is slightly larger than the registration target, which is the target for calculating the registration deviation value.

6. The registration system according to any of claims 1 to 5, wherein the light source (22) is a ring light source distributed around the lens of the image collector (21).

7. The registration system according to any of claims 1 to 6, wherein the embedded processor (25), the delay trigger board (23), the image collector (21), the light source (22) and the color patch sensor (24) are enclosed in a housing, and a sensor window for exposing the color patch sensor (24) and a collector window for exposing the image collector (21) are opened on the housing.

8. Registration system according to any of claims 1 to 7, wherein the light emitted by the light source (22) can be directed through the collector window onto the surface of the printed matter.

9. The registration system according to any of claims 1 to 8, further configured to perform the following procedure:

the embedded processor calculates the color register parameter correction value of the color register module corresponding to the color set according to the color register deviation value;

and correcting the color register parameters of the corresponding color groups according to the color register parameter correction values.

10. A printing apparatus employing the registration system of any of claims 1 to 9, wherein the printing apparatus comprises a plurality of colour groups, each colour group being downstream of a registration module.

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