CN210680101U

CN210680101U - Micro-point color code group for detecting overprint deviation of color printing

Info

Publication number: CN210680101U
Application number: CN201922154391.3U
Authority: CN
Inventors: 孙海涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2020-06-05
Anticipated expiration: 2029-12-05

Abstract

The utility model discloses a micro-point color code group for detecting color printing registration deviation, which belongs to the field of machine vision type color printing registration deviation detection color codes, and aims at the problem that the current image color codes are inconvenient for manual calibration and monitoring, the color code group provided by the utility model comprises a micro-point group and a visual measurement graph, the micro-point group is a pattern formed by sequentially printing micro-points arranged in M rows and N columns on the register area according to the color sequence of color register printing, the micro-points are circular points or rectangular points, the micro-points are arranged according to a certain rule, the visual inspection graph is a graph which is arranged beside the micro-point group and is sequentially printed at the same position according to the color sequence of color register printing, an operator can judge the register state by observing the visual inspection graph, if other colors appear at the edge, this may indicate a deviation in the color registration and the print control device for the last color may monitor the registration status for all colors.

Description

Micro-point color code group for detecting overprint deviation of color printing

Technical Field

The utility model belongs to machine vision formula color printing overprint deviation detects color mark field.

Background

When printing color patterns, the patterns are distributed into a plurality of printing plates according to different colors and are sequentially printed on a printing material. To ensure that an accurate and complete pattern can be formed when printing in sequence, it is necessary to detect the overprint bias by means of a colour mark or set of colour marks. There are two main categories of color codes currently used at home and abroad on printing machines for detecting deviations of a registration system:

1) firstly, photoelectric color codes, the shape of which is usually rectangle, triangle or trapezoid, sequentially print patterns and corresponding color codes on a printing material in the printing process, the distance between two adjacent color codes in each group of color codes has a set standard distance (such as 20mm), a registration system adopts a photoelectric sensor to detect the distance between two adjacent color codes, the difference value is registration deviation, and the registration control can be realized by processing the deviation value through an algorithm. The color code needs to be provided with a special color code printing area outside the edge of the printed product pattern, commonly called as a rim charge, and the rim charge is cut off after the printing is finished, so that the resource waste is caused.

2) Second, image-like patches, specialized images based on digital image processing techniques, serve as patches. The register control system uses a machine vision system composed of digital cameras to collect images to detect printing register deviation. The image color-like code is mostly patterns such as a micro-point type, a circle or an arc type, and the image color-like code only needs to be arranged in a blank in the printed matter or does not influence the position of the printed matter, does not occupy or occupies less rim charge, and can avoid resource waste. Image color-like scales are used in machine vision type registration control systems.

The current image color-similar code plays a role in automatic registration control in the running process of a machine by means of a machine identification function, the starting and running of a printing machine need manual monitoring and manual control, and the current image color-similar code cannot provide detection conditions for a registration system, so that the current image color-similar code is not adopted in a large scale. The utility model provides a color mark group who has automatic registration function and be convenient for artifical monitoring and artifical control again to improve work efficiency and be convenient for machine vision formula registration control system and popularize and apply.

Disclosure of Invention

The utility model provides a color code group for the color printing registration deviation detection, the color code group comprises the microdot group and the range estimation figure two parts that M row N was listed as and is arranged.

The function of the micro-point group is to detect the registration deviation based on the machine vision type registration control system,

the visual pattern is used for monitoring the printing condition and carrying out corresponding control by an operator.

1. Regarding the set of micro-dots: the micro-points of the micro-point group can be circular points or rectangular points, the typical value of the diameter of the circular points is 0.5-1.0 mm, the typical value of the side length of the rectangular points is 0.5-1.0 mm, and the typical value of the center distance of the micro-points is 3.0 mm.

Wherein the microdots are arranged according to the following rule:

1) the even-numbered rows of micro-points and the odd-numbered rows of micro-points are staggered, the longitudinal intervals of the rows are arranged at equal intervals, and the micro-points in the rows are also arranged at equal intervals;

2) the even-numbered row micro-points and the odd-numbered row micro-points are aligned with each other, the rows are arranged at equal intervals in the longitudinal direction, and the micro-points in the rows are also arranged at equal intervals;

3) when M is 0 or N is 0, the single-row micro-point group is formed; is ═ i

4) Micro point calibration: the micro-point group contains calibration micro-points. For a single row of micro-dot groups, the calibration micro-dots may be micro-dots set in the first color, or may be two micro-dots set in the first color; for the multi-row micro-dot set, the calibration micro-dot may be one micro-dot of the first color, or may be two or three micro-dots of different rows and columns set in the first color.

2. Visual inspection pattern: the visual inspection pattern is a pattern which is arranged beside the micro-point group and is printed at the same position of the printed product by multi-color overlapping, and can be a cross line, a circle, a triangle, a square and the like, and the cross line pattern is preferred.

Typical dimensions of cross-line visual inspection patterns: the line width is 0.1mm, the length of the line segment is 3.0-5.0 mm,

typical dimensions of the circular visual inspection pattern: the line width is 0.1mm, and the diameter of the circle is 3.0-5.0 mm.

The utility model has the advantages that:

the utility model provides a color code group belongs to image class color code. Because the color code group has small size, the color code group only needs to be arranged in a hollow white area of the printed matter or an area which does not influence the use of the printed matter and is beneficial to image acquisition, processing and deviation detection in a machine vision mode.

Use the utility model provides a registration control system of color mark group can save the rim charge, avoids the wasting of resources, and registration system has realized the digitization, detects the precision height.

The utility model provides a color code group will promote trade upgrading, establishes the basis for the trade realizes digitization, networking, intellectuality.

The utility model provides a range estimation figure in color mark group through the digital camera sampling to show the range estimation figure on corresponding colour printing controlgear's touch screen, the operator can judge the registration state through observing the range estimation figure, if the deviation appears in the overprint, then the figure linewidth after the seal still is the design linewidth, if the deviation appears in the overprint, then its linewidth widen or the colour appears in figure edge.

The print control device of each color can monitor the registration deviation of the previously printed color, and the print control device of the last color can monitor the registration deviation of all the colors.

Drawings

FIG. 1 is a color scale set consisting of a staggered circle micro-point set and a cross-line visual inspection graph.

FIG. 2 is a color scale group consisting of an aligned circle micro-point group and a cross-line visual observation graph.

Fig. 3 and 4 are color scale groups consisting of a single-row circle micro-point group and a cross-line visual observation graph.

Fig. 5, 7 and 8 are color scale groups consisting of a rectangular micro-point group and a circular visual observation figure.

FIG. 6 is a color scale set consisting of a circular micro-point set and a circular visual observation pattern.

Detailed Description

The technical solution of the present invention will be further explained and explained in the following with reference to the accompanying drawings in the form of specific embodiments.

Example 1

As shown in fig. 1, the color scale group in this embodiment is composed of two parts, namely, a micro-point group and an eye-measurement pattern, the micro-point group is a pattern formed by sequentially printing micro-points arranged in 4 rows and 4 columns on the registration area according to the color sequence required by printing, the micro-points are circular micro-points, the micro-points are staggered between the micro-points in even rows (2 nd row and 4 th row) and the micro-points in odd rows (1 st row and 3 rd row), the longitudinal intervals of the rows are equidistant, and the micro-points in the rows are also equidistant;

three points of the 2 nd row, the 1 st column, the 3 rd row, the 1 st column and the 2 nd column are selected as calibration micro points and are designed into micro points of the first color, and micro points of other colors are sequentially printed according to the set positions.

The typical value of the diameter of the circular dots is 0.5-1.0 mm, and the typical value of the center-to-center distance of the micro dots is 3.0 mm.

The micro-point group is used for machine vision identification, the micro-point calibration function is used for solving the pixel equivalent by the system by using the known camera parameters, and further solving the registration deviation of the printed color code and the calibration color code, thereby overcoming the distortion of the sampling image and ensuring the registration control precision.

1) Setting a camera of a machine vision registration control system to enable the camera to acquire a color code area image;

2) the method comprises the steps that a camera obtains a color code area image, and a front color code and a current color code are identified according to a color register printing sequence;

3) according to the dimension values of the color target, such as length l, height h and diameter 2r, given during the plate-making process, according to the given color target parameters and the row pixel values n contained in the color target in the image_xAnd column pixel value n_yCalculating the pixel equivalent k of the color patch region image_x，k_y

4) Identifying coordinates (x) of characteristic points of a pre-color patch in a patch region image₀,y₀) Simultaneously recognizing the characteristic point coordinates (x ', y') of the rear color patch in the patch area image, and obtaining the standard characteristic point coordinates (x ', y') of the rear color patch according to the given distance L between the front and rear color patches₀+N,y₀) Or (x)₀,y₀+M)；

5) Comparing and calculating the pixel difference between the characteristic point of the rear color code and the standard characteristic point of the rear color code;

6) converting the pixel difference into distance difference as registration deviation value

The visual pattern is a cross line printed beside the micro-point group, and is sequentially printed at the same position of the printed product according to the color sequence of the chromatography printing, and the typical size of the cross line is as follows: the line width is 0.1mm, and the length of the line segment is 3.0-5.0 mm.

The visual inspection graph is sampled by the digital camera and displayed on the touch screen of the corresponding color printing control equipment, an operator can judge the registration state by observing the visual inspection graph, if the registration is free of deviation, the line width of the printed graph is the designed line width, and if the registration is deviated, the line width of the graph can be widened or the edge of the graph is colored.

The print control device of each color can monitor the registration deviation of all the preceding colors, and the print control device of the last color can monitor the registration deviation of all the colors.

When the micro-point adopts a rectangular scheme, the side length of the rectangular micro-point is 0.5-1.0 mm, as shown in fig. 5, 6 and 8.

Example 2

As shown in fig. 2, the color patch set in this embodiment is different from embodiment 1 in that the even-numbered rows of dots (rows 2 and 4) and the odd-numbered rows of dots (rows 1 and 3) are aligned with each other, the rows are arranged at equal intervals in the longitudinal direction, and the dots in each row are also arranged at equal intervals.

Example 3

As shown in fig. 3, the color patch set in this embodiment is a single row of micro-dot set, and 4 dots in total, wherein the 1 st and 4 th dots are the micro-dots of the first color as the calibration dots, and the other color micro-dots are printed in sequence according to the calibration positions, and the single row of micro-dot set is suitable for the case where the color patch set is printed in a relatively narrow area.

Example 4

As shown in fig. 4, the color patch set in the present embodiment is a single row of micro-dot set, and the principle is the same as that of embodiment 3, and the present invention is applied to a case where the color patch set is printed in a relatively narrow area.

The micro-point color scale can be placed along the circumferential direction or the axial direction of the plate roller and used by a machine vision registration system so as to adapt to different printing products.

Claims

1. The micro-point color code group for detecting the color printing registration deviation is characterized by consisting of a micro-point group and an eye-measuring graph, wherein the micro-point group is a pattern formed by sequentially printing micro-points which are distributed in M rows and N columns in a registration area according to the color sequence required by the color registration printing, and M and N are integers which are not less than 0; the micro-points are circular points or rectangular points, and are arranged according to the following rules:

1) the even-numbered rows of micro-points and the odd-numbered rows of micro-points are arranged in a staggered manner, the longitudinal intervals of the rows are arranged at equal intervals, and the micro-points in the rows are also arranged at equal intervals;

2) the even-numbered row micro-points and the odd-numbered row micro-points are aligned, the longitudinal distance of each row is equidistant, and the micro-points in each row are also equidistant;

3) if M =0 or N =0, forming a single-row micro-point group;

4) micro point calibration: for a single row of micro-dot groups, the calibration micro-dots may be micro-dots set in the first color, or may be two micro-dots set in the first color; for the multi-row micro-dot set, the calibration micro-dot may be one micro-dot of the first color, or may be any two micro-dots or three micro-dots of different rows and columns set in the first color.

2. The set of microdot patches for chromatic printing registration deviation detection according to claim 1, in which the visual pattern is a pattern printed at the same position on the print by multi-color superimposition printed beside the microdot set.

3. The set of micro-dot color patches for detecting misregistration in color printing according to claim 1, wherein the diameter of the circular dots is typically 0.5 to 1.0mm when the micro-dots are circular dots.

4. The set of micro-point color patches for detecting color printing registration deviation according to claim 1, wherein when the micro-points are rectangular points, the typical design of the side length of the rectangular points is 0.5-1.0 mm.

5. The set of microdot patches for chromatic printing registration deviation detection according to any of claims 1-3, in which the typical design of the center-to-center spacing of the microdots is 3.0 mm.

6. The set of micro-point patches for chromatic printing registration deviation detection according to claim 1, in which the visual pattern may be a cross-hair, a circle, or a triangle.

7. The set of micro-point patches for chromatic printing registration deviation detection according to claim 6, in which the visual pattern is a cross-hair.

8. The set of micro-point patches for detecting misregistration in color printing according to claim 7, wherein the cross hairs have a typical line width of 0.1mm and a line length or circle diameter of 3.0 to 5.0 mm.