JPH0540014A - System for detecting position of object to be measured - Google Patents

Abstract

PURPOSE:To improve the detecting accuracy of positions of objects to be measured by reading the luminance of pixels in the direction perpendicular to a standard line and calculating the luminance difference between adjacent pixels. CONSTITUTION:By using the edge of the wiring pattern 5 of electronic parts 1 as a reference line K, the position of the pattern 5 is detected against a standard line H. A camera device 10 which takes the image of the line K is provided and a luminance reading section 12 reads the luminance of pixels in the direction perpendicular to the standard line H on a picture element coordinate system 11 which is set in the picture of the line K taken by the device 10 and on which the inclination of the line H is set to zero by paying attention to the luminance variation of pixels in the picture of the wiring pattern 5 taken by the device 10. A pixel coordinate reading-out section 15 reads out the pixel coordinates at which the luminance difference calculated by a luminance difference calculating section 14 which calculates the luminance difference between adjacent pixels becomes the maximum. Then a coordinate computing section 16 computes the coordinates of the reference line K by correcting the pixel coordinates read out by the section 15 by using the luminance difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detection method of an object to be measured useful for detecting the position of the object to be measured such as an electronic component.

[0002]

2. Description of the Related Art Conventionally, for example, when an electronic component 1 having a wiring pattern 5 as shown in FIG. 3 is assembled to another electronic component, the wiring pattern 5 of the electronic component 1 is used as a reference line K.
Is the position of the reference line K with respect to the standard line H (tilt, etc.)
Is visually detected with a microscope, and then the parallelism with respect to the standard line H is obtained to perform alignment, and the aligned electronic component 1 is assembled to another electronic component.

[0003]

However, since the above-mentioned conventional electronic component 1 is positioned by visual inspection with a microscope, the detection accuracy is poor, and therefore the alignment is likely to be insufficient. There was a problem of becoming.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a position detection system which improves the accuracy of position detection of an object to be measured.

[0005]

The technical means of the present invention for solving the above problems are as follows.

In the position detection method of the object to be measured in which the object to be measured having the reference line is imaged by the camera device and the position of the object to be measured with respect to the standard line is detected from the imaged result, the standard screen is the imaging screen of the reference line. A brightness reading unit that reads the brightness of a pixel in a direction orthogonal to a standard line in a pixel coordinate system where the slope of a line is zero, a brightness difference calculation unit that calculates a brightness difference between the brightness of adjacent pixels, and a brightness difference calculation unit. A pixel coordinate reading unit that reads out the pixel coordinate that maximizes the calculated brightness difference, and a coordinate calculation unit that corrects the pixel coordinates read by the pixel coordinate reading unit using the brightness difference and calculates the coordinates of the reference line. Be prepared.

[0007]

According to the position detecting method of the object to be measured having the above structure, when the object to be measured is imaged by the camera device, the brightness of the pixel in the direction orthogonal to the standard line is read and the brightness of the pixel of the adjacent pixel is read. The brightness difference is calculated. Next, the pixel coordinates having the maximum brightness difference are read out, and the coordinates of the reference line, in which the pixel coordinates having the maximum brightness difference are corrected using the brightness difference, are calculated in the coordinate calculation unit. In this case, since the correction is performed, highly accurate coordinates can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A position detecting method for an object to be measured according to an embodiment of the present invention will be described below with reference to the accompanying drawings. The position detection method of the object to be measured according to the embodiment is applied to the position detection of the electronic component 1 shown in FIG. 3 described above, and the edge of the wiring pattern 5 of the electronic component 1 is set as the reference line K and the position with respect to the standard line H is set. It is something to detect.

This position detecting method is, as shown in FIG.
A camera device 10 that captures an image of the reference line K is provided, and attention is paid to a change in luminance in an image of the wiring pattern 5 captured by the camera device 10.
The luminance reading unit 13 that reads the luminance of the pixel in the direction orthogonal to the standard line H in the pixel coordinate system 11 with the inclination of zero
A luminance difference calculation unit 14 that calculates the luminance difference between the luminances of adjacent pixels, a pixel coordinate reading unit 15 that reads out the pixel coordinates that maximizes the luminance difference calculated by the luminance difference calculation unit 14, and a pixel coordinate reading unit 15. A coordinate calculation unit 16 that corrects the pixel coordinates read by the CPU using the brightness difference to calculate the coordinates of the reference line K.
It has and.

The coordinate calculator 16 calculates the coordinates by the following mathematical formula.

[0011]

[Equation 1]

In Equation 1, Bn is a pixel coordinate that maximizes the brightness difference (in the embodiment, the one having the smaller coordinate is selected), Dn
m is the maximum brightness difference, Dm + 1 is 1 more than the maximum brightness difference
Luminance difference on the side with one coordinate, Dm + 2 is the luminance difference on the side with two coordinates larger than the maximum value of the luminance difference, and Dm-1 is the luminance difference on the side with one coordinate smaller than the maximum value of the luminance difference. , Dm-2 are the brightness differences on the side of which two coordinates are smaller than the maximum value of the brightness difference.

Therefore, according to this position detection method, first, in the pixel coordinate system 11 in which the inclination of the standard line H is zero in the image pickup screen of the reference line K shown in FIG. The luminance of the pixel in the direction orthogonal to the standard line H at some points on the X coordinate is read. FIG. 2 shows an example of the reading result (2 places). Next, the brightness difference calculation unit 14 calculates the brightness difference of the brightness of the adjacent pixels. The results are also shown in FIG. After that, the pixel coordinate reading unit 15 reads out the pixel coordinate at which the brightness difference calculated by the brightness difference calculating unit 14 is the maximum.

Then, the coordinate calculation unit 16 corrects the pixel coordinates read by the pixel coordinate reading unit 15 using the above-mentioned brightness difference, and calculates the coordinates of the reference line K. Figure 2 now
Explaining the case of the middle X1 point, the pixel coordinate Bn at which the brightness difference is maximum is 115, and the calculation result is as follows.

[0015]

[Equation 2]

In this way, the Y coordinate at some points of the X coordinate is obtained. In this case, since the coordinates are corrected in consideration of the weights of the upper and lower luminances, the accuracy is high. After that, the angle θ of the reference line K is calculated based on the coordinates calculated by the coordinate calculation unit 16, and the inclination is obtained.

Then, the electronic component 1 is moved by the calculated angle.
By rotating, the reference line K can be aligned with the standard line H in parallel. In this case, since the accuracy of the calculated angle is high, the error can be reduced.

Although the reference line K is set at the edge of the wiring pattern 5 in the above embodiment, the present invention is not limited to this and may be set at another portion.

[0019]

As described above, according to the position detecting method of the object to be measured of the present invention, the object to be measured is imaged by the camera device, and the coordinate calculation unit calculates the pixel coordinate having the maximum brightness difference. Since the coordinates of the reference line are calculated by making corrections using the difference, highly accurate coordinates can be obtained. In particular, simply reading pixel coordinates inevitably causes a quantization error of plus or minus one pixel. According to the present invention, the quantization error is 1
The number of pixels can be set to be less than or equal to the number of pixels, and accordingly, highly accurate coordinates can be obtained. As a result, the accuracy of detecting the position of the measured object can be significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a position detection system for an object to be measured according to the present invention.

FIG. 2 is a diagram showing an example of reading and calculation data of the position detection method according to the embodiment.

FIG. 3 is a diagram schematically showing an example of an electronic component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component 5 Wiring pattern K Reference line H Standard line 10 Camera device 11 Pixel coordinate system 13 Luminance reading unit 14 Luminance difference calculation unit 15 Pixel coordinate reading unit 16 Coordinate calculation unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Kirita 1-1-4 Umezono, Tsukuba-shi, Ibaraki Institute of Industrial Science and Technology (72) Inventor Toruo Minami width 26 Shizuta, Minamimura, Shiwa-gun, Iwate Prefecture 17-2 Iwate Prefectural Industrial Test Site (72) Inventor Jun Sasaki 26 Tsushima, Tsunami-mura, Minamimura, Shiwa-gun, Iwate Pref. 17-2 Inside Iwate Prefectural Industrial Test Site (72) Inventor Chisato Oshima 62 Takizawa Nozawa, Takizawa-mura, Iwate-gun, Iwate Prefecture −536 (72) Inventor Atsuhiro Nakano 3-12-12 Kagano, Morioka-shi, Iwate

Claims (1)

[Claims] 1. In a position detection method of an object to be measured in which an object to be measured having a reference line is imaged by a camera device and the position of the object to be measured with respect to the standard line is detected from the imaging result, an image of an image screen of the reference line is displayed. The brightness reading unit that reads the brightness of the pixel in the direction orthogonal to the standard line in the pixel coordinate system where the inclination of the standard line is zero, the brightness difference calculation unit that calculates the brightness difference between the brightness of the adjacent pixels, and the brightness difference calculation A pixel coordinate reading unit that reads out the pixel coordinate that maximizes the brightness difference calculated by the unit, and a coordinate calculation unit that corrects the pixel coordinates read by the pixel coordinate reading unit using the brightness difference to calculate the coordinates of the reference line. A method for detecting the position of an object to be measured, comprising: