KR102125388B1 - Substrate cutting apparatus of automatically adjusting cutting position and adjusting method for the same - Google Patents

Abstract

The present invention relates to a substrate cutting apparatus, which comprises: a head unit having a camera, lighting, and a cutting tool; a motion control unit for controlling a motion of the head unit; a reference coordinate registering unit for storing a reference coordinate of the cutting tool obtained from an image of a master substrate; an image processing unit including a region selecting unit for extracting a region-of-interest image from an image of a substrate to be cut, an image reinforcing unit for generating a reinforced image by removing noise from the region-of-interest image, a threshold value extracting unit for extracting a threshold value for distinguishing a background region corresponding to the substrate in the reinforced image and a target region corresponding to a cutting hole, and a binarization processing unit for converting the reinforced image into a binarized image using the threshold value extracted from the threshold extracting unit; and a corrected coordinate calculating unit for calculating a corrected coordinate of the cutting tool for the substrate to be cut by using the binarized image. According to the present invention, coordinates of a cutting start point and end point are automatically corrected for each loaded substrate to be cut and a cutting process is performed by using the corrected coordinates, such that the precision and productivity of a depaneling process can be greatly improved as compared to that of the conventional invention.

Description

Substrate cutting apparatus of automatically adjusting cutting position and adjusting method for the same}

The present invention relates to a substrate cutting equipment, specifically, the information obtained from the image data of the substrate to be cut is compared with a pre-registered reference coordinate to automatically calculate the correction coordinates and apply the calculated correction coordinates to perform the cutting operation. It relates to a substrate cutting equipment.

In general, electronic components installed in vehicles, aircraft, ships, and the like include sensors, actuators, and controllers.

In addition, the electronic controller (ECU) includes a circuit board printed circuit board (PCB), a processor mounted on the board, components such as memory, condensers, resistors, and control software stored in the memory and executed by the processor. .

When manufacturing such an electric controller, a component mounting process is performed for a substrate panel to which a plurality of substrate units are connected in order to increase productivity.

In the component mounting process, after the solder cream is applied to the substrate panel for component mounting, the components are mounted on the solder cream and high temperature is applied to join the components to the substrate panel.

Therefore, when component mounting is completed on all the substrate units of the substrate panel, each substrate unit must be separated from each other using a substrate cutting equipment. As described above, the operation of separating each of the substrate units on which a component is mounted from one substrate panel is called depaneling, and the substrate cutting equipment for this is called a depaneling router.

On the other hand, recently, as functions and uses of the controller for the battlefield are diversified, there are increasing cases where more controllers must be installed in a limited space or more control operations are performed using one controller.

Accordingly, the recent electronics controllers are becoming smaller and more highly integrated, and as the degree of integration of components increases, a very high level of process precision is required for the depaneling router.

This is because if the process precision of the depaneling router is low, there is an increased risk of product defects by damaging components or circuits mounted on the substrate unit during cutting.

In addition, if the process precision of the depaneling router is low, the size of the separated board unit or the location of the cut surface will exceed the tolerance, and as a result, assembly may not be possible at the final assembly stage, or conversely, vibration may occur due to play after assembly. Because it grows.

In order to prevent such product defects and assembly defects, it is necessary to accurately set the coordinates of the start and end points of the cutting operation for each substrate to be cut in the substrate cutting equipment.

However, conventionally, the operator manually sets the coordinates of the starting point and the ending point of the cutting operation while looking at the camera image of the loaded substrate panel.

However, since this method is a manual method of a worker, productivity is very low and there is a problem in that the possibility of error is large because it is necessary to rely on the naked eye.

On the other hand, in the above-described component mounting process, a tolerance may occur due to minute deformation of the substrate panel in the process of expansion and contraction of the substrate panel due to high temperature. Therefore, there is a problem in that the possibility of product defects is further increased because a positional error occurs between the substrate panel used by the operator to register the reference coordinates of the starting point and the end point of the cutting operation and the actually produced substrate panel.

Korean Registered Patent No. 10-1945039 (announcement of 2019.02.01)

The present invention is to solve such a conventional problem, by using the image data of the substrate to be cut cutting automatically correct the coordinates of the cutting start point and the end point to improve the process precision and productivity of the depaneling process The purpose is to provide cutting equipment.

In order to achieve the above object, an aspect of the present invention, a camera, lighting, and a head unit having a cutting tool; A motion control unit that controls the operation of the head unit; A reference coordinate registration unit for storing reference coordinates of the cutting tool obtained from the image of the master substrate; An area selection unit for extracting an image of a region of interest from an image of a substrate to be cut, an image enhancement unit for generating an image enhancement image by removing noise from the image of the region of interest, and a background region and a cutting corresponding to the substrate in the image enhancement image An image processing unit including a threshold extraction unit for extracting a threshold value for classifying a target area corresponding to a hole, and a binarization processing unit for converting the image-enhanced image into a binary image by using the threshold value extracted by the threshold extraction unit. ; It provides a substrate cutting equipment including a correction coordinate calculation unit for calculating the correction coordinates of the cutting tool for the substrate to be cut using the binarized image.

In the substrate cutting equipment according to an aspect of the present invention, the image processing unit includes a color information extracting unit that analyzes a pixel brightness value distribution for a portion of the region of interest and analyzes main background color information of the substrate to be cut, and the image The enhancement unit may convert the region of interest image into a single channel image using the main background color information, and remove the noise from the single channel image to generate the image enhancement image.

In addition, in the substrate cutting apparatus according to an aspect of the present invention, the threshold extracting unit, a reference threshold value extracted from the entire region of interest and a candidate threshold region having a smaller area than the region of interest and including a target region and a background region It is possible to determine a larger value as an optimal threshold value by contrasting the values. In addition, the candidate region includes a first candidate region including a first target region and a second candidate region including a first target region, and the threshold extracting unit includes a first candidate threshold value extracted from the first candidate region. And a smaller value among the second candidate threshold values extracted from the second candidate region and the reference threshold value to determine a larger value as an optimal threshold value.

In addition, in the substrate cutting equipment according to an aspect of the present invention, the binarization processing unit sets a brightness value of a pixel having a brightness value smaller than a threshold value extracted from the threshold value extraction unit to 255, and a brightness value greater than the threshold value. It is possible to binarize by setting the brightness value of a pixel with.

In addition, in the substrate cutting device according to an aspect of the present invention, the correction coordinate calculating unit is a point (a) and a point (b) at the upper boundary of the left and right target regions and the background region when the vertical axis of the binarized image is the y axis. , Find the straight line passing through the two left and right points (c) and (d) on the lower border of the left and right target areas and the background area, but in the case of the left target area, check the multiple pixel columns while moving from the leftmost pixel column to the middle. Then, the point where the difference between the y-axis coordinates of the pixel is the maximum is determined by the point (a) through which the upper boundary line passes and the point (c) through which the lower boundary line passes. By inspecting a row of pixels, the point at which the difference between the y-axis coordinates of the pixel becomes the maximum may be determined as a point (b) passing through the upper boundary line and a point (d) passing through the lower boundary line.

In another aspect of the present invention, a method of correcting coordinates of a cutting tool in a substrate cutting equipment, comprising: setting a reference coordinate of a starting point and an end point of a cutting tool from an image of a master substrate acquired through a camera; An image acquisition step of loading the substrate to be cut and obtaining an image of the substrate to be cut; A region of interest image extraction step of extracting a region of interest for calculating correction coordinates from the image of the substrate to be cut; An image enhancement step of removing noise from the region of interest image to generate an image enhancement image; A threshold extraction step of extracting a threshold value for distinguishing the background region corresponding to the substrate and the target region corresponding to the cutting hole from the image-enhanced image; Generating a binarized image from the image-enhanced image using the threshold value; It provides a method for correcting the cutting position in the substrate cutting equipment, including a coordinate correction step of extracting the positions of the starting and ending points of the work to the substrate to be cut from the binarized image and correcting the reference coordinates to calculate the corrected coordinates.

Another aspect of the present invention provides a computer-readable recording medium in which a program implementing the above-described cutting position correction method is recorded.

According to the present invention, since the coordinates of the cutting start point and the end point are automatically corrected for each loaded substrate to be cut, and the cutting process is performed using the corrected coordinates, the process precision and productivity of the depaneling process can be greatly improved compared to the prior art. have.

1 is a block diagram showing the configuration of a substrate cutting equipment according to an embodiment of the present invention.
2 is a block diagram of an image processing unit according to an embodiment of the present invention.
Figure 3 is a flow chart showing the operation of the substrate cutting equipment according to an embodiment of the present invention.
4 is a view showing a state of setting a reference coordinate using a master substrate
5 is a view showing a state of acquiring image data by photographing a substrate to be cut.
6 is a view showing a state of extracting the region of interest from the image of the substrate to be cut
7 is a view showing a state in which color information is extracted from a region of interest image
8 is a view showing a state in which a region of interest is converted into a single channel image.
9 is a view showing a state in which image enhancement is performed on a single channel image
10 is a view illustrating the position of the target area, the background area, and the cutting surface in the histogram.
11 is a view showing a state in which a threshold value is calculated from a region of interest and a candidate region that is divided.
12 is a diagram illustrating an optimal threshold value
13 is a view showing an image subjected to binarization processing based on an optimal threshold value.
14 is a view showing a method for calculating a correction coordinate according to an embodiment of the present invention
15A and 15B are diagrams illustrating a process of extracting coordinates of a work start point and an end point from an image of a substrate 10a to be cut.
FIG. 16 is a view showing a state in which the cutting area of the cutting target substrate and the reference cutting area of the master substrate are calculated through the process of FIGS. 15A and 15B to calculate the correction coordinates.
17A and 17B are views showing a process of extracting the coordinates of the start and end points of the work from the image of the substrate 10b to be cut.
FIG. 18 is a view showing a state in which the cutting area of the cutting target substrate and the reference cutting area of the master substrate are calculated in the course of FIGS. 17A and 17B to calculate the correction coordinates.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

For reference, when one element (element) is connected or combined with another component in the present specification, as well as when directly connected or combined with another component, indirectly connected or combined with another element in between. Also included. In addition, when one component is directly connected or directly coupled to another component, it means that the other component is not interposed. In addition, when a part includes or includes a certain component, it means that other components may be further included or provided instead of excluding other components unless otherwise specified. In addition, the drawings attached to the present specification are only for convenience of explanation and understanding, and of course, the scope of the present invention should not be interpreted or distorted due to this.

Substrate cutting equipment 100 according to an embodiment of the present invention, as illustrated in the block diagram of Figure 1, the head unit 110, the driving unit 120, the control unit 130, the storage unit 200, the input unit ( 210), a display 230, and the like.

The head unit 110 may include a cutting tool 112, a camera 114, and lighting 116. The cutting tool 112 includes a motor and a cutting tool, and the cutting tool may be a straight bit rotating about a vertical axis, a circular saw rotating about a horizontal axis, or other shapes.

The camera 114 is for acquiring image data by photographing a master substrate and a substrate to be cut. The image data of the master board can be used to set the reference coordinates. The image data of the substrate to be cut can be used to calculate the correction coordinates.

The lighting 116 illuminates a photographing part in order to photograph a more accurate image with the camera 114, but it is preferable that it is an LED light that can adjust the illuminance, but it is not limited thereto.

The driving unit 120 is for moving the head unit 120 in the horizontal and/or vertical direction, and may include an actuator such as a motor, a pneumatic cylinder, a hydraulic cylinder, and a moving shaft.

The driving unit 120 may move the entire head unit 120 or independently move at least one of the cutting tool 112, the camera 114, and the lighting 116 constituting the head unit 120. .

The control unit 130, functionally divided, motion control unit 140, camera control unit 150, lighting control unit 160, reference coordinate registration unit 170, image processing unit 180, correction coordinate calculation unit 190, etc. It may include.

The motion control unit 140 may perform a control operation of moving the entire head unit 110 to a predetermined position, or individually moving the cutting tool 112, the camera 114, and the lighting 116. Also, the motion control unit 140 may control the operation of the cutting tool 112.

The camera control unit 150 may perform control operations for on/off of the camera 114, photographing operation, magnification adjustment, and the like.

The lighting control unit 160 may perform control operations such as on/off of the lighting 116 and illumination adjustment.

The reference coordinate registration unit 170 serves to obtain and register reference coordinates of the cutting start and end points from the image data of the master substrate, and display the reference coordinate registration screen on the display 230 and the cutting start point entered by the operator through the screen. The coordinates of the end point and the end point may be stored in the storage unit 200.

The image processing unit 180 serves to process the image of the substrate to be cut in various ways and convert it into an image suitable for calculating the correction coordinates.

When functionally divided, the image processing unit 180, as shown in the block diagram of FIG. 2, the region selection unit 181, the color information extraction unit 182, the image enhancement unit 183, the threshold extraction unit 184 ), a binarization processing unit 185 and the like.

The region selection unit 181 serves to set the region of interest from the image of the substrate to be cut and to extract the image of the region. Based on the reference coordinates input by the operator, the size of the cutting tool, the cutting direction, the jig tolerance, and the shaking of the product when cutting can be considered to automatically extract the region of interest of the appropriate size. The region of interest includes a portion close to the target region among the target region (cutting hole region) and the background region (background of the substrate), and other noise elements such as chipsets and circuits in the background region are set to be excluded as much as possible.

In addition, the region of interest is extracted to a size that can sufficiently reflect the contrast difference between the target region and the background region so that the optimal threshold value extracted in the threshold extraction stage can secure the maximum representation of the pixel brightness value distribution of the target region and the background region. Should be.

In addition, when the operator inputs the reference coordinates, the target area must be set to enter the image of the camera.

The color information extraction unit 182 analyzes color information of the extracted image of the region of interest and serves to extract main background color information of the substrate to be cut. Through this, it is possible to obtain a color channel capable of sufficiently reflecting the contrast between the target area and the background area so that the optimal threshold value extracted in the threshold extraction step can secure the maximum representation of the pixel brightness value distribution between the target area and the background area. do. The color channel of the image may be red (R), green (G), blue (B), or a different color coordinate system may be used.

On the other hand, since the printed circuit board is generally a single color, when extracting color information, it is not necessary to analyze the entire region of interest, but only a partial region inside the region of interest. To this end, it is preferable to extract color information by setting an expected cutting movement section of the cutting tool as an area for extracting color information only. In order to prevent the rotational error or the lateral movement error of the substrate, the rotational error correction may be performed through a physical mark of the substrate in advance.

The image enhancement unit 183 extracts a single color channel corresponding to the main background color information using the color information extracted by the color information extraction unit 182, converts the region of interest image into a single channel image, and targets the single channel image. The image enhancement process is performed.

The image enhancement process targets a single channel image by removing noise, image noise, etc. by applying a noise reduction filter, while applying morphological operations to remove disturbances such as light scattering, spreading, and dust on the product surface. It plays a role of smoothing the boundary between the area and the background area.

The noise removal filter serves to remove the disturbances existing in the entire area of the image, and the morphological operation is performed by applying a local minimum value of the distribution of brightness values of a range of neighboring pixels for each pixel in a single channel image of the region of interest. It serves to remove the influence of foreign substances on the surface. At this time, one or more noise removal filters and morphological calculation techniques may be applied.

The threshold extracting unit 184 extracts an optimal threshold value that separates the target region (cutting hole region) from the background region (substrate) using a histogram distribution of pixel brightness values in a single channel image subjected to image enhancement processing.

In an embodiment of the present invention, the pixel brightness value distribution of the background area and the pixel brightness value distribution of the target area are clustered according to the histogram distribution, and based on this, candidate threshold values are derived, and the candidate threshold value and the size and position of each cluster The optimal threshold value is extracted by weighting each cluster in consideration of, number, and the like.

Specifically, a threshold value (reference threshold value) extracted for the entire image of the region of interest, a threshold value extracted for the left target region (first candidate threshold), and a threshold value extracted for the right target region (second) The candidate threshold value is calculated, and a voting method is applied to finally extract one of the optimal threshold values.

For example, the smaller of the threshold value for the left target area (first candidate threshold) and the threshold value for the right target area (second candidate threshold) and the threshold for the entire image (reference threshold) By comparison, a larger threshold can be finally determined as an optimal threshold. That is, if the reference threshold is greater than at least one of the first and second candidate thresholds, the reference threshold is extracted as the final threshold, and if the reference threshold is less than the first and second candidate thresholds, the first and second A small value among candidate thresholds can be extracted as an optimal threshold.

The binarization processing unit 185 converts the single channel image subjected to the image enhancement processing by the image enhancement unit 183 into binarization, that is, a black and white image based on the threshold value extracted by the threshold extraction unit 184.

The binarization processing unit 185 performs a task of converting a brightness value of a pixel having a brightness value equal to or lower than a threshold value extracted by the threshold extraction unit 184 to 255, and a brightness value of a pixel having a high brightness value to 0. Can be.

In this way, the target area displayed relatively dark in the image of the substrate to be cut is displayed in white, and the surrounding background area is displayed in black, so that the target area and the background area can be contrasted very clearly.

In FIG. 1 again, the correction coordinate calculating unit 190 serves to calculate the correction coordinates of a start point and an end point for the cutting operation of the cutting tool 112 from the image of the substrate to be binarized by the binarization processing unit 185.

To this end, the starting point of the cutting operation is determined in the first target area of the binarized image of the target substrate, the end point of the cutting operation is confirmed in the second target area, and the x-axis error is compared with the reference coordinates of the starting point and the end point, y Calculate the axis error and rotation error.

Subsequently, when the reference coordinates of the starting point and the end point are corrected in consideration of the calculated error and the diameter of the cutting tool, the correcting coordinates of the starting point and the ending point of the cutting operation for the loaded substrate to be cut are calculated.

When the correction coordinates are calculated, the motion control unit 140 moves the cutting tool 112 to the correction coordinates of the starting point of the cutting operation, and then starts the cutting operation by operating the cutting tool 112, and the cutting tool 112 cuts the operation. When the correction coordinate of the end point is reached, the operation of the cutting tool 112 ends.

Meanwhile, at least one of the motion control unit 140, the camera control unit 150, the lighting control unit 160, the reference coordinate registration unit 170, the image processing unit 180, and the correction coordinate calculation unit 190 of the control unit 130 is hardware. It may be implemented as software, or as a combination of hardware and software.

In addition, when implemented in software, each function of the control unit 130 may be implemented as software independent of each other, or two or more functions may be implemented as one integrated software. The software may be stored in the storage unit 200.

In addition, the control unit 130 includes software that performs functions such as motion control, camera control, lighting control, reference coordinate registration, image processing, and correction coordinate calculation, and processors, such as CPUs and MCUs (not shown in the figure), which execute these software. Um).

In this case, the processor may execute software that performs functions such as motion control, camera control, and lighting control, and output a predetermined control command to the head unit 110 and/or the driving unit 120.

In addition, the processor may execute software that performs registration of the reference coordinates, and set the reference coordinates using an image of a master board and a user input.

Also, the processor may execute software that performs image processing to convert the image of the substrate to be worked into an image suitable for calculating the correction coordinates.

In addition, the processor may execute a software that performs a correction coordinate calculation function to calculate the correction coordinates using the image and reference coordinates of the cutting target plate.

The storage unit 200 may store software for the operation of the substrate cutting equipment 100. Software is a set of instructions executed by a processor, and may include an operating system, middleware, an application, or an application programming interface (API).

The storage unit 200 may include a non-volatile memory (eg, flash memory, etc.) and a volatile memory (eg, random access memory (RAM). Software may be stored in a non-volatile memory and loaded and executed as a volatile memory. .

The storage unit 200 may store data or commands generated in each component of the substrate cutting equipment 100.

The input unit 210 is an interface for an operator to operate the substrate cutting equipment 100, and may be provided in the form of a keyboard, a touch pad, a touch screen, and the like.

The display 230 serves to display status information of the substrate cutting equipment 100, display an image of the substrate taken by the camera 114, or provide a user interface.

Hereinafter, a method for automatically correcting a cutting position in the substrate cutting equipment 100 according to an embodiment of the present invention will be described with reference to the flowchart of FIG. 3.

First, the operator must load the master substrate to the substrate cutting equipment 100 and perform a reference coordinate setting operation. The reference coordinate means the coordinates of the starting point and the ending point of the cutting operation obtained from the master substrate. Needless to say, the master substrate must be the same type of substrate as the substrate to be cut.

When the master substrate 10 as shown in FIG. 4 is loaded on the jig of the substrate cutting equipment 100, the operator moves the head unit 110 to move the head unit 110 to the center point of the photographing area 20 of the camera 114 (crosswise on the screen) Is displayed) in the cutting hole 12 corresponding to the starting point among the plurality of cutting holes 12 formed in the master substrate 10 and the coordinates of the starting point are registered as reference coordinates.

After setting the reference coordinates of the starting point, the head unit 110 is moved again so that the center point (indicated by a cross on the screen) of the photographing area 20 corresponds to the end point among the plurality of cutting holes 12 formed on the master substrate 10 Is placed in the cutting hole 12 and the coordinates of the end point are registered as reference coordinates.

Meanwhile, as shown in FIG. 4, a circular cutting tool pointer 22 is displayed at the center of the camera's photographing area 20 on a screen for setting a reference coordinate, and an operator operates the input unit 210 to operate the cutting tool pointer ( It is also possible to adjust the diameter of 22).

The operator can adjust the diameter of the cutting tool pointer 22 to the width of the cutting hole 12 while the cutting tool pointer 22 is positioned inside the cutting hole 12 of the master substrate 10. The diameter of the cutting tool pointer 22 corresponds to the diameter of the bit rotating about the vertical axis.

The operator can adjust the diameter of the cutting tool pointer 22 or move the position so that the curvature of the cutting tool pointer 22 matches the curvature of the inner edge of the cutting hole 12 while looking at the reference coordinate setting screen.

Therefore, the operator can more easily and accurately set the reference coordinates of the starting point and the end point of the cutting operation through the reference coordinate setting screen, and can also determine the diameter of a bit suitable for the cutting operation of the substrate.

The operator can register the diameter of the bit to be used as basic data. In addition, basic data on the magnification of the camera 114 and the illuminance of the lighting 116 can be registered. (ST11)

After completing the initial setting operation as described above, the cutting operation for the substrate to be cut is performed in earnest. To this end, the substrate to be cut is first placed on a jig of the substrate cutting equipment 100 and moved to a working position. (ST12)

When the substrate to be cut reaches the working position, the camera 114 is photographed with the substrate to be cut and image data is acquired.

5 shows a state in which image data is obtained for the first substrate to be cut 10a and the second substrate to be cut 10b, respectively. The first substrate to be cut 10a and the second substrate to be cut 10b are the same type of substrate, but when loaded into the substrate cutting equipment 100, there is a positional error as shown in the drawing by the tolerance of the jig and/or substrate. Can be seen.

When photographing the substrates 10a and 10b to be cut, when the photographing area 20 of the camera does not include both the starting point and the ending point of the cutting area, as shown in FIG. 5, the vicinity of the starting point, the middle part, the vicinity of the end point, etc. It is desirable to acquire the cutting path and surrounding images through image synthesis after continuously photographing overlapping with each other. (ST13)

After obtaining the image data of the substrates 10a and 10b to be cut as described above, image pre-processing is performed to convert them into images suitable for calculating coordinates.

To this end, as shown in FIG. 6, the region selection unit 181 of the image processing unit 180 extracts regions of interest 50a, 50b, and 50c from the image of the substrates 10a, 10b, and 10c to be cut. As described above, when setting the regions of interest 50a, 50b, 50c, the target region (cutting hole region) and the background region (background of the substrate) must include a portion close to the target region, and cutting based on the reference coordinates. It should be set to an appropriate size considering the size of the tool, cutting direction, jig tolerance, and product shaking during cutting. (ST14)

Subsequently, the color information extraction unit 182 of the image processing unit 180 analyzes the distribution of pixel brightness values in the extracted images of the regions of interest 50a, 50b, and 50c to extract key background color information of the substrate to be cut.

At this time, as shown in FIG. 7, only a portion of the region inside the region of interest is set as the color information extraction regions 55a, 55b, and 55c, and the distribution of pixel brightness values in the region is analyzed by histogram for each color channel, thereby relatively high pixel brightness. Main color channel information forming a distribution of values can be extracted. (ST15)

Subsequently, the image enhancement unit 183 of the image processing unit 180 performs an image enhancement operation for converting the images of the regions of interest 50a, 50b, and 50c into images suitable for threshold extraction.

First, the image enhancement unit 183 extracts a single color channel corresponding to the main background color information by using the color information extracted by the color information extraction unit 182, and as shown in FIG. 8, regions of interest 50a, 50b, 50c ) To convert a single channel image.

Subsequently, the image enhancement unit 183 removes dust, image noise, and the like in the image by applying a noise removal filter to a single channel image, while applying morphological calculations to disturb factors such as light scattering, spreading, and dust on the product surface. Remove it.

Through this, as shown in FIG. 9, image-enhanced images 60a and 60b in which the boundary between the target region and the background region are smoothly processed are obtained. (ST16)

Subsequently, the threshold extracting unit 184 of the image processing unit 180 clusters the pixel brightness value distribution in the image-enhanced images 60a and 60b, and determines an optimal threshold value that distinguishes the pixel brightness value clusters of the target region and the background region. To extract.

As can be seen through FIGS. 8 and 9, in general, when converted to a single channel image, the target area corresponding to the cutting hole appears black, and the background area corresponding to the surface of the substrate not only looks brighter than the target area Some parts may look very bright due to interference such as stains and foreign substances.

Looking at the distribution of the pixel brightness values of the single channel image as a histogram, as shown in FIG. 10, the brightness values of the target area pixels are distributed in groups near 0 (fully black), and the brightness values of the background area pixels are higher than the target area. It can be seen that it has a large value but is distributed in a cluster over a much wider range.

In an exemplary embodiment of the present invention, a threshold value for distinguishing the pixel brightness value of the target region from the pixel brightness value of the background region is set by using the brightness value distribution pattern. That is, as shown in FIG. 10, the pixel brightness value of the cutting surface corresponding to the boundary between the target area and the background area is extracted between the cluster of brightness values of the target area and the cluster of brightness values of the background area, and this is determined as a threshold value.

At this time, in order to calculate accurate correction coordinates, it is necessary to accurately extract the brightness value at which the cluster of background regions corresponding to the surface of the substrate starts from the histogram.

However, there may be cases where a small cluster of brightness values appears near the cutting surface due to dust or the like present on the cutting surface, and in some cases, it may be difficult to accurately extract the brightness value at which the clustering of the background area starts.

In an embodiment of the present invention, a voting method is applied to solve this problem.

Specifically, a reference threshold value that separates the target region and the background region is extracted using the distribution of brightness values of the entire image-enhanced image 60a of the region of interest, and a candidate region including a portion of the target region and the background region among the region of interest After extracting the candidate threshold value using the distribution of brightness values of, a larger one of the reference threshold value and the candidate threshold value is determined as the optimal threshold value.

In this way, a brightness value closer to the cluster of the background area can be extracted as a threshold value.

On the other hand, when there are two or more target regions in the region of interest as in the embodiment of the present invention, it is preferable to extract candidate threshold values for each target region and compare the smaller value with the reference threshold value.

That is, as illustrated in FIG. 11, a reference threshold value is extracted for the entire image-enhanced image 60a of the region of interest, and the first candidate region including a portion of the left target region and the background region among the regions of interest is targeted. A first candidate threshold value may be extracted, and a second candidate threshold value may be extracted for a second candidate region including a portion of a right target region and a background region from among regions of interest.

In this case, a smaller value among the first candidate threshold value and the second candidate threshold value is compared with the reference threshold value, and a larger value is extracted as an optimal threshold value. The reason why the smaller of the first candidate threshold value and the second candidate threshold value is compared with the reference threshold value is that when the target projection and the boundary surface (cutting surface) of the background area are attached with dust or foreign substances, the brightness value of the interface increases. This is because the threshold value tends to be larger than the state in which there is no dust or foreign matter, and therefore, the smaller of the first candidate threshold value and the second candidate threshold value is more likely to be a more accurate value.

On the other hand, when the first candidate threshold value and the second candidate threshold value are the same, one of the two is arbitrarily selected and a larger value is extracted as an optimal threshold value in comparison with the reference threshold value.

12 is a diagram showing the location of the optimal threshold value extracted by applying this method. (ST17)

Subsequently, the binarization processing unit 185 of the image processing unit 180 binarizes the image enhancement images 60a and 60b based on the threshold value extracted by the threshold extraction unit 184, so that the target region 72 is shown in FIG. 13. The binarized images 70a and 70b are displayed in white and the background area 71 is displayed in black. (ST18)

When the image preprocessing for the image of the substrate to be cut is completed through the above process, the start and end points of the cutting operation are extracted for the binarized images 70a and 70b, and the start point registered in step ST11 is cut in comparison with the reference coordinate of the end point. Calculate the correction coordinates of the start and end points of the work. (ST19)

When the correction coordinates are calculated, the cutting tool 112 is moved to the correction coordinates of the starting point of the cutting operation, and then the cutting operation is started. When the cutting tool 112 reaches the correction coordinates of the cutting operation endpoint, the operation of the cutting tool 112 Terminates. Subsequently, the cutting tool 112 is moved to the next working area, or the substrate to be cut is unloaded from the equipment. (ST20)

Hereinafter, a process of calculating the correction coordinates of the starting point and the ending point of the cutting target substrate using the images pre-processed by the image processing unit 180 will be described with reference to the flowchart of FIG. 14 and FIGS. 15A and 15B. 15A and 15B show a process of calculating the correction coordinates for the region of interest 50a of the substrate 10a to be cut shown in FIG. 6(a).

First, the correction coordinate calculating unit 190 analyzes the pixels of the binarized image 70a that has been preprocessed for the region of interest, and extracts the upper and lower straight lines of the cutting region.

Specifically, as shown in Fig. 15A (a), when the vertical axis of the binarized image 70a is the y-axis coordinate, the point (a) on the upper boundary of the left target area 72 and the background area 71 Obtain a straight line passing through the point (b) at the upper boundary of the target area 72 and the background area 71 and the right and left at the lower boundary of the left and right target areas 72 and the background area 71 through the same process. Find the straight line passing through two points (c) and (d).

At this time, in order to extract the ultra-precision cutting area, not only one pixel column is inspected in the pixel column in the y-axis direction of the left and right target areas, but a plurality of pixel columns are inspected, and the y-axis coordinates of pixels at the upper boundary line and pixels at the lower boundary line It is desirable to determine the two points ((a) and (c), (b) and (d)) where the difference between is maximum.

In other words, in the case of the left target area, the point where the difference between the y-axis coordinates of the pixel becomes the maximum and the point where the upper boundary line passes (a) and the lower boundary line pass through by inspecting multiple pixel columns from the leftmost pixel column to the center. It is preferable to decide with (c).

Similarly, in the case of the right target area, a point where the difference between the y-axis coordinates of the pixel becomes the maximum by moving from the rightmost pixel column to the center, and the point where the upper boundary line passes (b) and the lower boundary line passes ( It is preferable to determine with d).

In this way, when the boundary between the target area and the background area is uneven due to other noise factors such as dust, it is possible to prevent the cutting area from being incorrectly extracted. In addition, although the binarization is performed based on the optimal threshold value extracted in the previous step, the influence of cutting area extraction due to noise in the background, which is still likely to occur, can be minimized. (ST31)

Subsequently, a central straight line located between the upper straight line and the lower straight line extracted in the above step is extracted.

Specifically, as shown in Fig. 15A (b), the center point (e) between the points (a) and (c) is extracted with respect to the y-axis, and between the points (b) and (d) After extracting the middle point (f), if a straight line passing through the point (e) and the point (f) is obtained, the center straight line is extracted. (ST32)

Subsequently, as shown in FIG. 15A(c), the boundary point between the target area 72 on the left and the background area 71 is extracted from the center straight line as the end point g of the convex arc of the left cutting hole, and the target area on the right. The boundary point between 72 and the background area 71 is extracted as the end point h of the convex arc of the right cutting hole. (ST33)

Subsequently, as shown in FIG. 15B (d), the coordinates of the cutting start point and the end point are extracted using the diameter information of the pre-registered cutting tool at the end points g and h of the left and right cutting holes. Specifically, the position of the point (i), which is 1/2 of the diameter of the cutting tool along the center straight line from the end point (g) of the left target area (72), is extracted as the starting point of the cutting operation, and the right target area (72) The position of the point j, which is half the diameter of the cutting tool along the center straight line from the end point h, is extracted as the end point of the cutting operation. (ST34)

Thereafter, an error is calculated by comparing the coordinates extracted in the above process with the pre-registered reference coordinates.

Specifically, as shown in FIG. 15B (e), two straight lines perpendicular to the average slope of the upper straight line and the lower straight line are extracted while passing through the start point and the end point, respectively. Also, new upper and lower straight lines with average slope of upper and lower straight lines are extracted.

Subsequently, a new upper straight line and a lower straight line having an average slope and a rectangle having 4 points as each vertex where two straight lines perpendicular to the average slope meet are extracted.

FIG. 15B (f) shows the extracted rectangle, which corresponds to the cutting area 80 of the substrate to be cut.

Subsequently, as shown in FIG. 16, the lateral movement in the xy-axis direction of the substrate to be cut is contrasted with the rectangle of the cutting target cutting area 80 and the rectangle of the reference cutting area 90 extracted from the image of the pre-registered master substrate. Calculate errors and/or rotational errors. (ST35)

Subsequently, by correcting the reference coordinates of the cutting start point and the end point using the calculated error, it is possible to calculate the correction coordinates for the cutting operation on the substrate to be cut.

When the correction coordinates are calculated in this way, the motion control unit 140 starts the cutting operation by moving the cutting tool 112 to the correction coordinates of the starting point of the cutting operation, and when the cutting tool 112 reaches the correction coordinates of the cutting operation end point, Just finish the work on the cutting area. (ST36)

17A, 16B, and 18 show the process of calculating the correction coordinates for the region of interest 50b of the substrate to be cut 10b shown in FIG. 6(b).

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, but can be modified or modified in various forms, and the modified or modified embodiments of the present invention disclosed in the claims below. If the technical idea is included, it will be obvious that it belongs to the scope of the present invention.

10: master substrate 10a, 10b, 10c: cutting table 12: cutting hole
20: shooting area 22: cutting tool pointer 30: reference line
50a, 50b, 50c: Region of interest 50a, 50b, 50c: Color information extraction region
60a, 60b: Image enhancement image 70a, 70b: Binary image
71: background area 72: target area 80: cutting area of the substrate to be cut
90: reference cutting area 100: substrate cutting equipment 110: head unit
112: cutting tool 114: camera 116: lighting
120: driving unit 130: control unit 140: motion control unit
150: camera control unit 160: lighting control unit 170: reference coordinate registration unit
180: image processing unit 181: area selection unit 182: color information extraction unit
183: image enhancement unit 184: threshold extraction unit 185: binarization processing unit
190: correction coordinate calculation unit 200: storage unit 210: input unit
220: display

Claims (10)

A head unit having a camera, lighting, and a cutting tool;
A motion control unit that controls the operation of the head unit;
A reference coordinate registration unit for storing reference coordinates of the cutting tool obtained from the image of the master substrate;
An area selection unit for extracting an image of a region of interest from an image of a substrate to be cut, an image enhancement unit for generating an image enhancement image by removing noise from the image of the region of interest, and a background region and a cutting corresponding to the substrate in the image enhancement image An image processing unit including a threshold extraction unit for extracting a threshold value for classifying a target area corresponding to a hole, and a binarization processing unit for converting the image-enhanced image into a binary image by using the threshold value extracted by the threshold extraction unit. ;
A correction coordinate calculation unit for calculating the correction coordinates of the cutting tool for the substrate to be cut using the binarized image
Substrate cutting equipment comprising According to claim 1,
The image processing unit includes a color information extraction unit that analyzes a distribution of pixel brightness values for a portion of the region of interest and analyzes main background color information of the substrate to be cut,
The image enhancement unit converts the region of interest image into a single channel image using the main background color information, and removes noise from the single channel image to generate the image enhancement image. According to claim 1,
The threshold extracting unit compares a reference threshold value extracted from the whole region of interest and a candidate threshold value extracted from a candidate region including a target region and a background region having a smaller area than the region of interest, and a larger value as an optimal threshold value. Substrate cutting equipment characterized by determining According to claim 3,
The candidate region includes a first candidate region including a first target region and a second candidate region including a second target region,
The threshold extracting unit compares a smaller value between the first candidate threshold value extracted from the first candidate region and the second candidate threshold value extracted from the second candidate region and the reference threshold value, to obtain an optimal threshold value. Substrate cutting equipment, characterized in that determined by According to claim 1,
The binarization processing unit sets the brightness value of a pixel having a brightness value smaller than a threshold value extracted by the threshold extraction unit to 255, and sets the brightness value of a pixel having a brightness value larger than the threshold value to 0 to binarize. Substrate cutting equipment, characterized in that. According to claim 1,
The correction coordinate calculating unit, when the vertical axis of the binarized image is the y-axis, points (a) and (b) at the upper boundary of the left and right target regions and the background region, and the left and right at the lower boundary of the left and right target regions and the background region. Find the straight line passing through two points (c), (d),
In the case of the left target area, a plurality of pixel columns are inspected while moving from the leftmost pixel column to the center, and the point at which the difference between the y-axis coordinates of the pixel becomes the largest (a) and the point at which the lower boundary passes (c) ),
In the case of the right target area, a plurality of pixel columns are inspected while moving from the rightmost pixel column to the center, and the point at which the difference between the y-axis coordinates of the pixel becomes the maximum is the point at which the upper boundary passes (b) and the point at which the lower boundary passes (d Substrate cutting equipment, characterized in that determined by. In the method of correcting the coordinates of the cutting tool in the substrate cutting equipment,
A reference coordinate setting step of setting reference coordinates of the starting and ending points of the cutting tool from the image of the master substrate acquired through the camera;
An image acquisition step of loading the substrate to be cut and obtaining an image of the substrate to be cut;
A region of interest image extraction step of extracting a region of interest for calculating correction coordinates from the image of the substrate to be cut;
An image enhancement step of removing noise from the region of interest image to generate an image enhancement image;
A threshold extraction step of extracting a threshold value for distinguishing the background region corresponding to the substrate and the target region corresponding to the cutting hole from the image-enhanced image;
Generating a binarized image from the image-enhanced image using the threshold value;
A coordinate correction step of extracting the positions of the starting and ending points of the substrate to be cut from the binarized image and correcting the reference coordinates to calculate the corrected coordinates
Method for correcting a cutting position in a substrate cutting equipment including The method of claim 7,
In the threshold extraction step, a larger value is compared with a reference threshold value extracted from the entire region of interest and a candidate threshold value extracted from a candidate region having a smaller area than the region of interest and including a target region and a background region as an optimal threshold value. Characterized by determining the cutting position correction method in the substrate cutting equipment The method of claim 8,
The candidate region includes a first candidate region including a first target region and a second candidate region including a first target region,
In the threshold value extraction step, the smaller threshold value among the first candidate threshold value extracted from the first candidate region and the second candidate threshold value extracted from the second candidate region is compared with the reference threshold value to optimize the larger threshold value. A method for correcting a cutting position in a substrate cutting equipment, characterized by determining by a value A computer-readable recording medium in which a program implementing the method for correcting a cutting position according to any one of claims 7 to 9 is recorded.

Images