JP2001291095A - Position recognition mark detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position recognition mark detection method which can surely detect the center of a position recognition mark with no influence caused by a faulty detection body even though the shapes of a detection bodies making up the recognition mark have a fault. SOLUTION: The binarized centroid of concentrical detection bodies A-H is detected by means of a position recognition mark made up of 9 points, and primary linear expressions 1-4 (y=ax+b) are calculated from the centroid positions of detection bodies facing each other. Then a mark center (X, Y), i.e., the intersection coordinates are calculated by two primary linear expressions consisting of one of combinations of 1 and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, and 3 and 4 of the expressions 1-4. In such a constitution of a detection algorithm, the center of the position recognition mark is detected by means of a combination of two primary linear expressions excluding the faulty one of bodies A-H.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a position recognition mark on a printed circuit board or the like.

[0002]

2. Description of the Related Art In a conventional position recognition mark detection method, a position recognition mark formed by a detection object such as a circle formed on the surface of a printed circuit board or the like is captured by an image recognition camera or the like, and the image processing of the image signal is performed. And a method of detecting the center of the position recognition mark by calculating the center of gravity of the position recognition mark on the entire operation screen from the binarization processing, or a method of detecting the center of the position recognition mark from the shading pattern matching processing. .

[0003]

However, in the above-described conventional method for detecting a position recognition mark, as shown in the center detection diagram of the position recognition mark in FIG. In the case of having, the detection method for obtaining the center of gravity of the position recognition mark on the entire screen by the above-described binarization processing cannot detect the normal center of gravity position, and the density pattern matching processing uses the registered reference In order to match the center with the location with high matching ability due to the correlation with the mark, basically the matching with the defective position recognition mark is a process in which the normal mark center cannot be detected. There is a problem that the position of the defect mark center detection position K is detected with respect to the position J.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and even if the shape of a detection object forming a position recognition mark has a defect, the shape of the detection object is not affected by the detection object having the defect.
It is an object of the present invention to provide a position recognition mark detection method capable of detecting a center of a stable position recognition mark.

[0005]

According to the present invention, there is provided a method for detecting a position recognition mark according to the present invention, comprising the steps of:
The binarization of the detection objects arranged in the concentric circles, the detection of the presence or absence of a defect in the detection center and the detection of the defect in the detection object, and further obtaining the linear equation from the position of the center of gravity of the corresponding detection objects, is not a detection object having a defect among them. This is a position recognition mark detection method for obtaining the coordinates of the intersection, which is the center of the position recognition mark, using two primary linear formulas. Even if a part of the detected object has a defect, the position recognition mark is not affected. The center of the mark can be detected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, in a position recognition mark in which a plurality of detection objects are arranged on a center and a concentric circle, binarization of the detection objects arranged in the concentric circles and detection of a center of gravity are performed. And detecting the presence / absence of a defect in the detection object, further obtaining a linear equation from the center of gravity of the corresponding detection object,
This is a position recognition mark detection method that obtains the intersection coordinates that are the centers of the position recognition marks using one primary linear formula. Even if the shape of the detection object has some defects, the center of the position recognition marks can be surely detected. It has the effect of being detectable.

According to a second aspect of the present invention, an image recognition camera and a processing mechanism perform image recognition and image processing of the position recognition mark by arranging a plurality of circular detection objects. This is a method for detecting a position recognition mark according to the first aspect of the present invention, and has the effect of reliably detecting a position recognition mark regardless of the presence or absence of a defect of the position recognition mark and its position.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual explanatory diagram of a center detection algorithm of a position recognition mark formed by nine detection objects according to an embodiment of the present invention. FIG. 2 is a plan view of the shape of the position recognition mark by the nine detection objects. 3 is a conceptual explanatory diagram of a center detection algorithm of a position recognition mark by nine detectors having the same part defect, and FIG. 4 is an operation function flow chart of the center detection algorithm of the position recognition mark in FIG.

As shown in FIG. 2, the shape of the position recognizing mark is formed by a total of nine points including eight circular detectors 11 arranged concentrically and one circular detector 12 at the center thereof. Have been.

Utilizing the position recognition marks by the nine detection objects, the binarization processing 5 is performed in the center detection algorithm of the nine-point position recognition marks shown in FIGS.
, The area of the circular detector at each of the eight points from the circular detector A to the circular detector H in the detection processing 6, the fillet diameter (length and width of each circular detector), The center of gravity is detected, and whether or not there is a defect is confirmed based on the circular detection object area and the fillet diameter of each of the eight points in the confirmation processing 7. From the center of gravity position of each non-defect detection object in the equation setting processing 8, The primary linear equation from 1 to 4 shown in FIG. 1 (y = ax +
b), and using any one of the combinations of 1 and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, and 3 and 4, the two primary linear equations detected in the coordinate setting processing 9 , The intersection coordinates (X, Y) of the position recognition mark center are obtained, and the intersection coordinates (X, Y) in the position recognition processing 10 become the whole, that is, the center position of nine detection objects, and the center of the nine position recognition marks is determined. The one-circle detection object I can be confirmed as a guide of the center position.

Next, for example, as shown in FIG. 3, even if there is an area defect in the detectors Aa and Ba, the primary linear equation 2a between the center of gravity of the detector Ca and the center of gravity of the detector Ga, and the detector Da
From the combination of the linear center equation 4a of the center of gravity of the detection object Ha and the center of gravity of the detection object Ha, the intersection coordinates, that is, the center of the nine position recognition marks (Xa , Ya) can be detected, and the center position of the entire position recognition mark can be detected even if the shape of the detection object forming each position recognition mark has some defects.

Therefore, according to the above description, for the shapes of the nine position recognition marks, the nine detectors have some defects from the algorithm by the binarized barycenter method of the eight detectors in the concentric circle. Even if it is, it is possible to detect the centers of the regular nine position recognition marks without being affected by the defective part.

As for the shape of the position recognition mark, not only the above-described nine circular detection bodies but also the number of circular detection bodies of nine or more points or a shape other than a circular shape can be applied. In addition, this detection method is applicable not only to the position recognition mark of the printed circuit board but also to the detection of the position recognition mark of another product.

[0014]

As described above, the position-recognition mark detection method according to the present invention uses the position-recognition mark shape and the center detection algorithm thereof, and has a defect in the shape of the constituent detection object. Even if it does, there is an effect that the center detection of the position recognition mark can be performed stably without being affected by the detection object having the defect.

[Brief description of the drawings]

FIG. 1 is a conceptual explanatory diagram of a center detection algorithm of a position recognition mark in which a detection object is formed at nine points according to an embodiment of the present invention.

FIG. 2 is a plan view of a shape of a position recognition mark formed by nine detection objects.

FIG. 3 is a conceptual explanatory diagram of a center detection algorithm of a position recognition mark by nine detectors having the same part defect.

FIG. 4 is an operation function flowchart of a center detection algorithm of a position recognition mark in FIG. 1;

FIG. 5 is a center detection diagram of a position recognition mark.

[Explanation of symbols]

 1-4 Linear linear equation 5 Binarization processing 6 Detection processing 7 Confirmation processing 8 Expression setting processing 9 Coordinate setting processing 10 Position recognition processing 11, 12 Detected objects A to H Circular detected objects Aa to Ha Circular detected objects I 1 Detector of circular dot J Detected position of normal mark center K Detected position of defect mark center X, Y Position recognition mark center Xa, Ya Position recognition mark center

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Yukihiro Hiraishi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.F-term (reference) AA03 BA19 CA12 CA16 CB06 CB12 CB16 CC01 CE12 CH08 DA03 DA07 DB02 DB08 DC03 DC04 DC06 5L096 AA07 BA03 CA04 DA02 EA43 FA10 FA59 FA60 FA64 FA69 FA73

Claims (2)

[Claims] In a position recognition mark in which a plurality of detection objects are arranged on a center and a concentric circle, binarization of a detection object arranged in the concentric circle, detection of a center of gravity, and detection of presence / absence of a defect in the detection object are performed. A position-recognition-mark detection method in which a primary linear expression is determined from the positions of the centers of gravity of the detected objects, and the intersection coordinates, which are the centers of the position-recognition marks, are determined by two primary linear expressions that are not detected and have a defect among them. 2. The position recognition mark according to claim 1, wherein the position recognition mark in which a plurality of circular detection objects are arranged is subjected to image recognition and image processing of the position recognition mark by an image recognition camera and a processing mechanism. Detection method.