JP2006127238A - Method for detecting center position of pixel of imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting the center position of pixels of an imaging device by which the center position of effective pixels of the imaging device can be accurately detected. <P>SOLUTION: The method comprises: a step (S1) for recognizing four element chip sides of an element chip as an image; a step (S2) for interpolating pixels of density images in the vicinities of four element chip sides; a step (S3) for calculating a plurality of edge positions for four sides of the element chip in each subpixel; a step (S4) for calculating an equation of lines of four element chip sides on image coordinates passing a plurality of edge positions, a step (S5) for obtaining each of the coordinates of an intersecting point of two orthogonal sides and the coordinates of an intersecting point of other two sides opposed to the former two sides; a step (S6) for recognizing the center of the coordinates of the two intersecting points as the center of the element chip, and a step (S7) for offsetting the center of the element chip by a value obtained by multiplying a difference between the position of the center of the element chip and the position of the center of an effective pixel part on the element chip by the magnification of a camera which is measured beforehand and recognizing the offset position as the center position of the pixels of the imaging device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a detection method of a pixel center position of an image sensor that can accurately recognize the pixel center of the image sensor. In particular, the present invention relates to a method for detecting the pixel center position of an image sensor that can realize assembling of an image pickup module in which the pixel center of the image sensor being miniaturized and the optical axis center of an optical member are precisely matched.

  Conventionally, as a method for detecting the center of a pixel of an image sensor, it is common to perform position recognition by marking a reference point on the package of the image sensor, or to recognize the image position of the outer shape of the package. However, in recent imaging modules that require precise positioning due to their small size and high accuracy, there is no space for providing a reference mark. In addition, in the image position recognition based on the outer shape, the positioning accuracy is determined by the outer shape and the effective pixel portion position. There is a problem that high-precision positioning cannot be performed.

  In order to solve this problem, a method has been proposed in which the edge of the effective pixel of the image sensor is detected, and the center value of the mounting holder is aligned with the center of the effective pixel frame so that the optical axis of the image sensor is aligned. (For example, refer to Patent Document 1). As shown in FIG. 12, the optical axis alignment method of the image sensor described in Patent Document 1 detects the edge of the effective pixel portion in the x direction 112 of the image sensor 100 by using a camera (not shown) installed in the apparatus. Scan multiple times. Thereby, the line edge 101 of the effective pixel portion is obtained.

Next, similarly, the edge detection of the effective pixel portion in the y direction 113 is performed by scanning the x direction 112 a plurality of times to obtain the line edge 103 of the effective pixel portion. The detection of the line edges 101 and 103 is performed after image processing such as edge enhancement is performed in order to increase the luminance difference between the light and shade edges and increase the accuracy of edge detection.
Next, the intersection point 105 between the line edge 101 and the line edge 103 is obtained as a coordinate value in image processing, the line edge 102 and the line edge 104 are obtained by the same operation, and the intersection point B106 and the intersection point C107 between the line edges are similarly obtained. Ask for. In this technique, the intersection 110, that is, the effective pixel center position is obtained from the center line 114 passing through the midpoint 108 between the intersection 105 and the intersection 106 and the center line 115 passing through the midpoint 109 between the intersection 106 and the intersection 107.
JP-A-5-316400

  However, there are many cases where the edge of the effective pixel portion of the image sensor does not have a clear gray level difference from a portion that is not an effective pixel. In such an image sensor, the method of aligning the optical axis of the image sensor described in Patent Document 1 above Even if is used, the line edge cannot be detected with high accuracy. For this reason, there is a problem that the effective pixel center position cannot be obtained with high accuracy.

  The present invention has been made to solve the above-described problem, and is an image sensor that can accurately detect the effective pixel center position of the image sensor even if the image sensor does not clearly show the effective pixel edge of the image sensor. An object of the present invention is to provide a method for detecting the pixel center position.

In order to achieve the above object, the present invention provides the following means.
The method of detecting the pixel center position of the image sensor according to the present invention includes a step of recognizing four element chip sides of a rectangular element chip provided in a positioned image sensor, and a density near the four element chip sides. A step of interpolating between pixels of an image, a step of dividing a plurality of edge positions on the element chip side into four sub-pixels based on the interpolated image data, and image coordinates passing through the plurality of edge positions A step of determining a linear equation of four element chip sides above, a step of obtaining coordinates of an intersection of two orthogonal sides and an intersection of the other two sides opposite to each other from the linear equation of the four sides, A step of recognizing the center of coordinates of two intersection points as the center of the element chip, and a camera measured in advance in a difference in position between the center of the element chip and the center of the effective pixel portion on the element chip Amount obtained by multiplying the magnification is offset a center of the device chip, and having a recognizing step of this position as a pixel center position of the image pickup device.

  According to the detection method of the pixel center position of the image sensor according to the present invention, first, the image of the element chip side is recognized, and the coordinates of the intersection point of the other two sides facing the intersection point of the two orthogonal sides of the element chip are obtained. The midpoint is determined as the center of the element chip. Then, the center of the element chip is offset by the amount obtained by multiplying the difference between the position of the center of the element chip and the center of the effective pixel portion and the magnification of the camera measured in advance, and this position is imaged. It is recognized as the effective pixel center of the element. Therefore, when the effective pixel center of the image sensor is obtained, it can be obtained without recognizing the edge of the effective pixel portion of the image sensor as in the prior art. Thus, the center position of the effective pixel portion can be determined with high accuracy.

  The method for detecting the pixel center position of the image sensor of the present invention includes a step of recognizing two or three element chip sides of a rectangular element chip provided in a positioned image sensor, A step of interpolating between pixels of a grayscale image in the vicinity of the element chip side, and a step of dividing a plurality of edge positions on the element chip side into two sides or three sides in units of subpixels based on the interpolated image data , Determining a linear equation of two or three element chip sides on image coordinates passing through the plurality of edge positions, and image coordinates of two orthogonal sides from the linear equation of the two or three element chip sides From the step of obtaining one intersection point above and the linear equation of one of the two orthogonal points starting from the intersection point, the length of one side and a pre-measured camera magnification The step of determining the image coordinate position of the apex of the element chip, and the other of the two sides orthogonal to each other on the linear equation of the other side, facing the apex from the length of one side and the pre-measured magnification of the camera Determining the image coordinate positions of the vertices, recognizing the midpoint coordinates of the image coordinates of the two vertices as the center of the element chip, and the effective pixel portion of the element chip and the effective pixel portion on the element chip. And a step of offsetting the center of the element chip by an amount obtained by multiplying a difference in position with the center by a camera magnification measured in advance, and recognizing the position as the pixel center position of the image sensor.

  According to the detection method of the pixel center position of the image pickup device according to the present invention, when one or two sides of the element chip side are not clearly visible, two or three element chip sides of the element chip that are clearly visible are determined. Image recognition is performed, and on the two recognized sides, the image coordinate positions of two vertices facing each other of the element chip are determined from the length of one side and the magnification of the camera measured in advance. By calculating the midpoint coordinates from these two vertices and using it as the center of the element chip, and then multiplying the difference in position between the center of the element chip and the center of the effective pixel portion and the magnification of the camera measured in advance. The center of the element chip is offset by the obtained amount, and this position is recognized as the effective pixel center of the image sensor. Therefore, even when one or two sides of the element chip cannot be clearly seen, it is possible to accurately determine the center position of the effective pixel portion.

The present invention has the following effects.
According to the pixel center position detecting method of the image sensor according to the present invention, the image of the element chip side of the image sensor is recognized and determined as the center of the element chip. Thereafter, the center of the element chip is offset, and this position is recognized as the effective pixel center of the image sensor. Therefore, when determining the effective pixel center of the image sensor, the center position of the effective pixel can be accurately determined by recognizing the image of the element chip side of the element chip even for an image sensor in which the edge of the effective pixel portion of the image sensor is not clearly visible. Since it can detect, the assembly of a highly accurate imaging module is realizable.

Next, a first embodiment of the present invention will be described with reference to FIGS.
A method for detecting the pixel center position of the image sensor 1 according to the present embodiment will be described with reference to the flowchart shown in FIG. The imaging element 1 includes a chip frame 3 in which a recess 3a is formed, and an element chip 4 disposed in the recess 3a. The sizes of the recess 3a and the element chip 4 are substantially equal.
First, the image sensor 1 and the element chip 4 that have been positioned are recognized by a position recognition camera (not shown) installed in the apparatus. Thereby, the image states of the image sensor 1 and the element chip 4 as shown in FIG. 2 are recognized. The recognized image of the image sensor 1 is captured on the image coordinates 2 of the position recognition camera (not shown) as, for example, grayscale pixel data of the VGA screen (0, 0) to (640, 480) (step S1). ).

  Next, the grayscale image data in the vicinity of edge portions (edge positions) described later of the four element chip sides 10a, 10b, 10c, and 10d forming the inside of the chip frame 3 of the image sensor 1 are divided into three dividing lines X1, X2, and X2. The area is divided into 16 areas by X3 and Y1, Y2, and Y3. Then, inter-pixel data is interpolated in sub-pixel units by spline interpolation or quadratic curve approximation on each of the dividing lines X1, X2, X3, Y1, Y2, and Y3. Here, each of the element chip sides 10a, 10b, 10c, and 10d includes an effective pixel portion 4a on the element chip 4 in a portion surrounded by the element chip sides 10a, 10b, 10c, and 10d, and an element including a scanning portion 4b that is not the effective pixel portion 4a. The end side of the chip 4 is shown. Further, the chip frame 3 is arranged on the outer periphery of the scanning unit 4b.

Subsequently, the details of the interpolation processing of the grayscale data in the vicinity of the edge portion 12a in the X1 portion of the one side 10a among the element chip sides 10a, 10b, 10c, and 10d will be described as an example. Will be described. Here, the edge portion indicates each intersection of the element chip sides 10a, 10b, 10c, 10d and the dividing lines X1, X2, X3 and Y1, Y2, Y3.
First, as shown in FIG. 3, grayscale image data in the Y direction near the edge portion 12a is captured. Then, when the grayscale data in the vicinity of the edge portion 12a is taken as the Y-direction address on the horizontal axis and the grayscale data on the vertical axis, a scatter diagram as shown in FIG. 4 is obtained. In this state, if the edge detection threshold is about 40, the Y-direction address of the edge portion is 14. Next, the scatter diagram shown in FIG. 4 is obtained by interpolating the grayscale data between the pixels from the grayscale data for each pixel by 1/10 pixel unit, that is, by quadratic curve interpolation or spline interpolation in subpixel units. As shown in FIG. 5, it becomes a smooth curve.

Further, the edge portion 12b at the X2 portion of the element chip side 10a, the edge portion 12c at the X3 portion of the element chip side 10a, the edge portion 12d at the Y1 portion of the element chip side 10b, and the Y2 portion of the element chip side 10b. Edge portion 12e, edge portion 12f at Y3 portion of element chip side 10b, edge portion 12g at X1 portion of element chip side 10c, edge portion 12h at X2 portion of element chip side 10c, and X3 portion of element chip side 10c The same applies to the edge portion 12i at the edge portion 12j, the edge portion 12j at the Y1 portion of the element chip side 10d, the edge portion 12k at the Y2 portion of the element chip side 10d, and the edge portion 12l at the Y3 portion of the element chip side 10d. Approximation and interpolation processing are performed (step S2).
Each element chip side 10a, 10b, 10c, 10d is divided into three parts, but it may be divided into two parts or more than four parts.

  Next, based on the above-described approximation or interpolated grayscale data, the edge portions 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k of the element chip sides 10a, 10b, 10c, 10d and An edge coordinate that cuts a predetermined threshold value of 12 l is obtained. For example, if the threshold value is 40 in the vicinity of the edge portion 12a, the Y coordinate of the edge portion 12a of the element chip side 10a can be obtained with high accuracy in units of subpixels as shown in 13.2. Similarly, the Y coordinates of the edge portions 12b, 12c, 12g, 12h, and 12i and the X coordinates of the edge portions 12d, 12e, 12f, 12j, 12k, and 12l are obtained in units of subpixels (step S3).

  Next, an equation of a straight line on the image coordinate 2 of the element chip sides 10a, 10b, 10c, and 10d is obtained based on the edge coordinates in subpixel units. As shown in FIG. 6, the equation shows that the Y coordinate value of the detected edge portion 12a at the X1 point of the element chip side 10a is 13.2 and the Y coordinate value of the detected edge portion 12b at the X2 point. Since the value of 13.5 and the value of the Y coordinate of the detected edge portion 12c at the point X3 is 13.8, if X1 = 100, X2 = 320, and X3 = 540, the value on the image coordinate 2 The linear equation of the element chip side 10a is y = 0.00136x + 13.064. This is an equation obtained by approximating a linear equation passing through a plurality of edge portions (12a, 12b, 12c). Similarly, linear equations on the image coordinates 2 of the element chip sides 10b, 10c, and 10d are obtained based on the detected coordinates of the edge portions 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k, and 12l. Calculate (step S4).

  Next, an intersection 13a of 10d orthogonal to the element chip side 10a is arithmetically calculated from the above two linear equations. Similarly, an intersection 13c of 10c orthogonal to the element chip side 10b is arithmetically calculated from the above two linear equations (step S5). In this embodiment, the intersection 13a between the element chip side 10a and the element chip side 10d and the intersection 13c between the element chip side 10b and the element chip side 10c are obtained, but instead, the element chip side 10a and the element chip side 10c are obtained. The intersection 13b with the chip side 10b and the intersection 13d with the element chip side 10c and the element chip side 10d may be obtained.

  Subsequently, the midpoint coordinate 5 (Cx, Cy) between the intersection 13a and the intersection 13c or between the intersection 13b and the intersection 13d is calculated. If the coordinates of the intersection 13a are (Kx1, Ky1), the coordinates of the intersection 13b are (Kx2, Ky2), the coordinates of the intersection 13c are (Kx3, Ky3), and the coordinates of the intersection 13d are (Kx4, Ky4), Cx = (Kx1 + Kx3) ) / 2, or Cx = (Kx2 + Kx4) / 2, Cy = (Ky1 + Ky3) / 2, or Cy = (Ky2 + Ky4) / 2 (step S6).

After calculating the midpoint coordinates 5 (Cx, Cy), as shown in FIG. 7, the midpoint coordinates (center) 5 of the element chip 4 and the effective pixel portion center position (effective pixel) on the drawing of the effective pixel portion 4 (Center) 6, a shift amount 7 in the X coordinate direction and a shift amount 8 in the Y coordinate are obtained. Based on the obtained shift amount 7 in the X coordinate direction, shift amount 8 in the Y coordinate, and the pre-measured magnification of the camera, the actual center position (pixel center position) of the image sensor 1 and the effective pixel portion center position 6 are determined. Calculate the offset amount. Here, the magnification of the camera image in the X coordinate direction is Cbx [pixel / mm], the magnification of the camera image in the Y coordinate direction is Cby [pixel / mm], the center position of the image sensor 1 and the effective pixel portion center position 6 When the amount of deviation 7 in the X coordinate direction is Zx [pixel] and the amount of deviation 8 in the Y coordinate direction is Zy [pixel],
Zx [pixel] = (deviation amount in X direction on drawing 7) [mm] × Cbx [pixel / mm]
Zy [pixel] = (Y-direction misalignment 8 in the drawing) [mm] × Cby [pixel / mm].
Next, coordinates (Cx + Zx, C) offset from the center coordinates 5 (Cx, Cy) of the detected element chip 4 by the amount of deviation (Zx, Zy) between the center position of the image sensor 1 and the effective pixel portion center position 6. Cy + Zy) is obtained as the actual center position of the effective pixel (step S7).

  According to the detection method of the pixel center position of the imaging device according to the present embodiment, the device chip sides 10a, 10b, 10c, and 10d are image-recognized, and the intersecting point 13a and the intersecting point 13c or the intersecting point 13b of the recognized device chip 4 are recognized. The image coordinates of the intersection 13d are obtained, and the midpoint is determined as the center of the element chip 4. Thereafter, the difference between the position on the drawing between the center coordinate 5 of the element chip 4 and the effective pixel portion center position 6 is multiplied by the pre-measured camera magnification, thereby offsetting the center coordinate by the determined amount. The position is recognized as the effective pixel center. Therefore, even when the effective pixel image is unclear, the actual effective pixel center position (Cx + Zx, Cy + Zy) of the image sensor 1 can be determined with high accuracy.

Next, a second embodiment according to the present invention will be described with reference to FIGS. In each of the embodiments described below, the description of the image sensor 1 according to the first embodiment described above and the description of the parts common to the pixel center position detection method of the image sensor 1 will be omitted.
A method for detecting the pixel center position of the image sensor according to the present embodiment will be described with reference to the flowchart shown in FIG.
In the detection method of the pixel center position of the image sensor according to the present embodiment, the difference from the first embodiment is that the step of recognizing two orthogonal element chip sides 10a and 10b of the element chip 4 (step S11), 2 From the linear equation of the two element chip sides 10a and 10b, the length information of the two element chip sides 10a and 10b on the drawing, and the pre-measured magnification of the camera, A step of obtaining coordinates (step S15) and a step of recognizing the midpoint coordinates of the two vertices 13a and 13c facing the image pickup device 1 as the center coordinates (Cx, Cy) of the element chip 4 (step S16).

  In step S11, one of the element chip sides 10a, 10b, 10c, 10d of the element chip 4 (chip side 10a in the example shown in FIG. 9A) and another side orthogonal to this one side ( In the example shown in FIG. 9A, only the chip side 10b) is image-recognized, and in the two sides that have been image-recognized, three points on each element chip side 10a, 10b (in the example shown in FIG. 9A, the intersection 13a , 13b, 13c) Interpolation is performed between pixels of the grayscale image in the vicinity by spline interpolation (step S12). Next, based on the interpolated data, the edge portions of the element chip sides 10a and 10b are detected in sub-pixel units. Then, a linear equation on the image coordinate 2 of the two element chip sides 10a and 10b is calculated based on the information on the edge portions of the chip sides 10a and 10b determined in units of subpixels (step S14).

  In step S15, the linear equation on the image coordinate 2 of the element chip sides 10a and 10b obtained in step S14 is satisfied, and as shown in FIG. 9A, the intersection of the chip side 10a and the chip side 10b. Starting from 13b, two distance positions obtained by multiplying the lengths of the element chip sides 10a and 10b on the drawing by a pre-measured camera magnification, that is, images of two vertices 13a and 13c facing the element chip 4 The coordinates on coordinate 2 are obtained.

  In step S16, the midpoint coordinates of the two vertices 13a and 13c obtained in step S15 are recognized as the midpoint coordinates (center) 5 of the element chip 4. Thereafter, similarly to the first embodiment, coordinates (Cx + Zx, Cy + Zy) offset by an amount of deviation (Zx, Zy) between the actual center position (pixel center position) of the image sensor 1 and the effective pixel portion center position 6 are used. Is determined as the center position of the actual effective pixel (step S17).

  According to the detection method of the pixel center position of the image sensor according to the present embodiment, when one or two sides of the element chip side cannot be clearly seen, two sides of the element chip sides 10a and 10b that are clearly visible are imaged. The image coordinate positions of the two vertices 13a and 13c facing each other of the element chip 4 are determined from the length of one side and the pre-measured magnification of the camera on the two recognized sides. The midpoint coordinate 5 (Cx, Cy) is obtained from the two vertices 13a and 13c, and then the difference between the position on the drawing between the center 5 of the element chip 4 and the effective pixel portion center position 6 is measured in advance. The center coordinate 5 is offset by the amount obtained by multiplying by the magnification of the camera, and this position is recognized as the effective pixel center position (Cx + Zx, Cy + Zy). Therefore, even when one or two sides of the element chip side cannot be clearly seen, it is possible to accurately determine the center position of the effective pixel portion 4.

  In this embodiment, as shown in FIG. 9A, the two sides 10a and 10b are used. However, the present invention is not limited to this, and in addition to the two sides 10a and 10b, from FIG. 9B. As shown in FIG. 9C, there are three possible ways: two sides 10b and 10c, two sides 10c and 10d, and two sides 10d and 10a. The best two sides should be selected.

  Further, the coordinates of the vertices 13a and 13c of the element chip 4 were obtained from the two orthogonal element chip sides 10a and 10b. As shown in FIG. 10, the three element chip sides 10a, 10b and 10c are image-recognized. The apex 13b of the element chip 4 may be obtained. Then, the linear equation on the image coordinate 2 of the element chip sides 10a, 10b, and 10c obtained in step S14 is satisfied, and the vertex 13d of the element chip 4 is set as a starting point, and the element chip sides 10a, 10b, and 10c on the drawing are used. A point at a distance position obtained by multiplying the length of the camera by a pre-measured camera magnification is recognized as another vertex 13d of the image sensor 1. Subsequently, by performing step S16 and the subsequent steps, it is more preferable to obtain the center of the effective pixel from the three element chip sides 10a, 10b, and 10c than to obtain the center of the effective pixel from the two orthogonal element chip sides 10a and 10b. It is possible to obtain with high accuracy.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in each of the above embodiments, as shown in FIG. 11, a transparent cover glass 21 may be provided on the end surface 3 b of the chip frame 3 so that the imaging element 20 covers the upper part of the element chip 4. Thus, by providing the transparent cover glass 21, the element chip 4 arranged in the recess 3a can be protected.

4 is a flowchart illustrating a method for detecting a pixel center position of the image sensor according to the first embodiment of the present invention. It is a top view which shows the image pick-up element which concerns on 1st Embodiment of this invention. The relationship between the image coordinate detected by the detection method of the pixel center position of the image pick-up element which concerns on 1st Embodiment of this invention, and grayscale data is shown. It is a graph which shows the relationship between the image coordinate detected by the detection method of the pixel center position of the image sensor which concerns on 1st Embodiment of this invention, and light / dark data. 4 is a graph showing the relationship between image coordinates obtained by performing quadratic curve interpolation or spline interpolation in FIG. It is a top view which shows the detection method of the pixel center position of the image pick-up element which concerns on 1st Embodiment of this invention. It is a top view which shows the detection method of the pixel center position of the image pick-up element which concerns on 1st Embodiment of this invention. It is a flowchart which shows the detection method of the pixel center position of the image pick-up element which concerns on 2nd Embodiment of this invention. It is the schematic which shows the detection method of the pixel center position of the image pick-up element which concerns on 2nd Embodiment of this invention. It is the schematic which shows the other modification of the detection method of the pixel center position of the image pick-up element which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing which shows the modification of the image pick-up element which concerns on 1st, 2nd embodiment of this invention. It is a top view which shows the pixel center position of the image pick-up element detected by the conventional detection method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 Image coordinate 4a Effective pixel part 5 Center of element chip 6 Effective pixel part center position (effective pixel center)
12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k, 12l Edge portions 13a, 13c, 13b, 13d

Claims (2)

A step of recognizing four element chip sides of a rectangular element chip provided in the positioned image sensor;
Interpolating between pixels of the gray image near the four element chip sides;
Based on the interpolated image data, a step of dividing a plurality of edge positions on the element chip side into four sides in units of subpixels;
Determining a linear equation of four element chip sides on image coordinates passing through the plurality of edge positions;
Obtaining the coordinates of the intersection of two orthogonal sides and the intersection of the other two sides opposite to each other from the linear equation of the four sides;
Recognizing the center of the coordinates of the two intersection points as the center of the element chip;
The center of the element chip is offset by an amount obtained by multiplying the difference in position between the center of the element chip and the center of the effective pixel portion on the element chip by a pre-measured camera magnification, and this position is set as the pixel of the image sensor. And a step of recognizing the center position as a center position. A step of recognizing two or three element chip sides of a rectangular element chip provided in the positioned image sensor;
Interpolating between pixels of the gray image near the two or three element chip sides;
Based on the interpolated image data, a step of dividing a plurality of edge positions on the element chip side into two or three sides in subpixel units;
Determining a linear equation of two or three element chip sides on image coordinates passing through the plurality of edge positions;
Obtaining one intersection point on the image coordinates of two orthogonal sides from the linear equation of the two or three element chip sides;
Starting from the intersection, the image coordinate position of one vertex of the element chip is determined from the length of one side and the pre-measured magnification of the camera on the linear equation of one of the two orthogonal sides. Process,
Determining the image coordinate position of another vertex facing the vertex from the length of one side and the magnification of the camera measured in advance on the linear equation of the other side of the two orthogonal sides;
Recognizing the midpoint coordinates of the image coordinate positions of the two vertices as the center of the element chip;
The center of the element chip is offset by an amount obtained by multiplying the difference in position between the center of the element chip and the center of the effective pixel portion on the element chip by a pre-measured camera magnification, and this position is set as the pixel of the image sensor. And a step of recognizing the center position as a center position.

Images