JP4239854B2 - Coil pass / fail judgment method, coil manufacturing method, and coil pass / fail judgment device - Google Patents

Description

  The present invention relates to a winding coil quality determination method and quality determination apparatus, and more particularly to a coil quality determination method, determination apparatus, and coil manufacturing method for imaging the appearance of a coil and determining the quality of a coil based on a captured image.

  A conventional appearance inspection (turbulent winding determination) of a wound winding coil has been performed as follows. FIG. 1 is an explanatory diagram of a conventional coil quality inspection method. As shown in the figure, a coil 50 that is a winding coil is composed of a winding part 51 and a bobbin 52 around which the winding part 51 is wound. Here, a silhouette image of the coil on the side surface of the coil 50 (for example, in the YZ plane in the example of FIG. 1) between the edge portions 53 to 54 of the winding portion 51 is imaged using an imaging means 100 such as a CCD camera. To do. FIGS. 2B and 2D show examples of this captured image.

FIG. 2A is a side view of the coil 50 in the case of a non-defective coil, and FIG. 2B is a silhouette image thereof. On the other hand, FIG. 2 (C) is a side view of the coil 50 in the case of a defective coil, and FIG. 2 (D) is a silhouette image thereof.
As shown in the figure, the winding of the non-defective coil is neatly wound around the bobbin 52, and therefore the amount of unevenness G appearing between the edge portions 53 to 54 of the winding portion 51 of the silhouette image is small. However, in the silhouette image of the defective coil wound up randomly, the amount G of unevenness appearing between the edge portions 53 to 54 on the side surface of the coil 50 increases.

  Therefore, in the conventional inspection method, the unevenness amount G of the silhouette image of the edge portion of the winding portion of the coil to be inspected is obtained, and when the unevenness amount G is equal to or less than a predetermined allowable value, it is determined that the coil to be inspected is a good product. When the amount G exceeds this allowable value, it was determined that the coil to be inspected was defective.

  There is no prior art document to be described regarding the present invention. This is because the prior art known to the applicant is not related to the literature known invention.

  However, the coil winding disorder (turbulent winding) may occur only with respect to the disturbance of the winding line array, with little unevenness at the edge of the winding part 51. FIG. 2 (E) is a side view of a defective coil when turbulent winding occurs due to disturbance of the line train of windings, and FIG. 2 (F) is a silhouette image thereof.

  As shown in FIG. 2E, the line array of the winding portion 51 of the defective coil shown in FIG. 2E is greatly disturbed compared to that of the non-defective coil in FIG. There is not much unevenness. In the case of such a turbulent winding, the unevenness amount G of the silhouette image of the edge portion shown in FIG. 2 (F) does not increase so as to exceed the above-described allowable value. Therefore, the conventional inspection method described above has a problem in that it is not possible to determine the coil winding that occurs due to the disturbance of the line array.

  Further, in the conventional inspection method, since the unevenness appearing on the edge portion of the side surface of the coil is detected, only one side surface of the coil can be inspected with one captured image. Therefore, in order to inspect the entire circumference of the coil 50, the above-described imaging and inspection must be repeated for the other side surfaces of the coil 50, and a determination time is required.

  In view of the above problems, the present invention provides a coil pass / fail determination method and a coil pass / fail determination apparatus capable of performing a coil pass / fail inspection using a captured image of a coil more accurately and at higher speed. Objective.

The inventors of the present invention have focused on the fact that a certain repetitive pattern appears in the image of the winding portion in the captured image of the non-defective coil in which the winding is correctly wound.
Based on this viewpoint, in the present invention, a spatial frequency corresponding to a repetitive pattern appearing in a winding portion of a captured image of a known good coil is obtained in advance, and the space of the captured image of the coil to be inspected is near this spatial frequency. The quality of the coil to be inspected is determined based on whether or not frequency components are collected.

  That is, the coil pass / fail determination method according to the first aspect of the present invention acquires a captured image of a coil to be inspected which is an image to be inspected, acquires a spatial frequency range including a spatial frequency component appearing in the captured image of a non-defective coil, The intensity distribution of the spatial frequency component of the image to be inspected is generated, the degree of gathering of the generated intensity distribution in the acquired spatial frequency range is determined, and the quality of the inspected coil is determined.

  The coil manufacturing method according to the second aspect of the present invention uses the coil quality determination method according to the first aspect to determine the quality of the manufactured coil.

  A coil pass / fail determination apparatus according to a third embodiment of the present invention includes an inspected image acquisition unit that acquires an image of an inspected coil that is an inspected image, and a spatial frequency range that includes a spatial frequency component that appears in the captured image of the non-defective coil. A spatial frequency range acquisition unit that acquires a spatial frequency component intensity distribution generation unit that generates an intensity distribution of a spatial frequency component of the acquired image to be inspected, and a determination of how the intensity distributions are generated in the acquired spatial frequency range And a determination unit that determines the quality of the coil to be inspected.

  The generation of the intensity distribution of the spatial frequency component of the inspected image is obtained by obtaining the spatial frequency component intensity of the inspected image in the inspected range on the inspected image, and for each position and each spatial frequency in the inspected range. Generate the intensity distribution of the components.

  The inspection range may be a one-dimensional region on the inspection image. At this time, the spatial frequency component intensity distribution is a two-dimensional intensity distribution generated for each position of the inspection range and each spatial frequency. Further, the inspection range may be a two-dimensional region on the inspection image. At this time, the spatial frequency component intensity distribution is a three-dimensional intensity distribution generated for each position of the inspection range and each spatial frequency.

  In the spatial frequency range including the spatial frequency component appearing in the picked-up image of the non-defective coil, the determination of how the spatial frequency component intensity distribution generated for the image to be inspected is determined in the spatial frequency range in the spatial frequency component intensity distribution. Alternatively, an intensity distribution region of a spatial frequency component having an intensity exceeding a predetermined first threshold value may be obtained, and it may be determined by determining whether or not the size of the intensity distribution region exceeds a predetermined second threshold value. This is because as the intensity distribution gathers, the distribution area of the intensity exceeding the predetermined threshold becomes larger.

  When the inspection range is a one-dimensional region on the inspection image, the size of the intensity distribution region for comparing the magnitude with the second threshold is an area, and the inspection range is a two-dimensional region on the inspection image. Is, the size of the intensity distribution region is the volume.

In addition to the above, the determination of the degree of gathering may be performed by further determining whether the size of the edge of the intensity distribution region is smaller than a predetermined third threshold value. For example, when the inspection range is a one-dimensional region on the inspection image, the edge size of the intensity distribution region is the outer peripheral length of the intensity distribution region. For example, the inspection range is a two-dimensional region on the inspection image. In this case, the edge size of the intensity distribution region is the surface area of the intensity distribution region.
When the intensity distribution is more concentrated and gathered at one point, the shape of the distribution area whose intensity exceeds a predetermined threshold also approaches a circle or a sphere, so that the ratio of the edge size to the size of the distribution area itself is reduced. This is because when the distribution is less concentrated, the shape of the distribution region is greatly distorted or split, and the ratio of the size of the edge to the size of the distribution region itself increases.

  Furthermore, the calculation of the spatial frequency component intensity from the inspected image may be performed by wavelet transform of the image signal of the inspected image.

In the coil quality determination method and the coil quality determination device according to the present invention, the spatial frequency component appearing in the winding portion of the captured image of the coil to be inspected corresponds to the repetitive pattern appearing in the winding portion of the captured image of the known good coil. Pass / fail is determined based on how much is collected near the spatial frequency component.
Therefore, if the line winding is disturbed in the winding of the coil to be inspected, the spatial frequency component appearing in the winding is detected as a component different from that of the non-defective product. Is possible. Thus, the determination accuracy can be improved as compared with the conventional determination method.

The image to be inspected used in the coil quality determination method and the coil quality determination device according to the present invention only needs to include a repetitive pattern that appears in the winding portion. An image (or a bottom image) may be used.
By using the top surface image (or bottom surface image) of the coil, the entire circumference of the coil can be inspected with only one image to be inspected, so that the time required for pass / fail judgment can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a configuration diagram of a coil pass / fail determination apparatus according to an embodiment of the present invention. The coil pass / fail determination apparatus 1 includes an inspected image acquisition unit 2 that acquires an inspected image that is an image signal (image data) obtained by imaging the inspected coil 50 that should be determined to pass or fail, and a spatial frequency that appears in the captured image of the non-defective coil. A spatial frequency range acquisition unit 3 that acquires a spatial frequency range including components, a spatial frequency component intensity distribution generation unit 4 that generates an intensity distribution of a spatial frequency component of the inspected image acquired by the inspected image acquisition unit 2, and a space The inspected range acquisition / setting unit 5 for acquiring or setting the inspected range on the inspected image for which the frequency component intensity distribution generating unit 4 should generate the intensity distribution, and the spatial frequency range acquired by the spatial frequency range acquiring unit 3 And a determination unit 6 that determines the degree of intensity distribution generated by the spatial frequency component intensity distribution generation unit 4 to determine whether the coil to be inspected is good or bad.

  Hereinafter, the coil quality determination method will be described with reference to FIGS. 4, 5 </ b> A, and 5 </ b> B. FIG. 4 is a flowchart of a coil pass / fail determination method according to the present invention, FIG. 5 (A) is an illustration of an inspected image of a non-defective coil, and FIG. 5 (B) is a diagram showing the spatial frequency component intensity distribution. .

  In step S <b> 101, the inspected image acquisition unit 2 inputs an inspected image of the inspected coil 50 captured by the external imaging unit 100 that can be realized by a CCD camera or the like from the imaging unit 100. An example of the inspection image is shown in an image 55 in FIG. An image 55 is a top view obtained by imaging the coil 50 shown in FIG. 1 with respect to the XY plane.

In step S102, the spatial frequency range acquisition unit 3 converts an external spatial frequency range input unit (not shown) into a spatial frequency range fw including a spatial frequency component corresponding to a repetitive pattern appearing in a winding portion of a captured image of a non-defective coil. )).
Such a spatial frequency range fw may be acquired as a frequency band having a predetermined allowable error range centered on a spatial frequency corresponding to a repetitive pattern appearing in a winding portion of a captured image of a non-defective coil, for example.

  In step S103, the inspected range acquisition / setting unit 5 selects the inspected range in which the spatial frequency component intensity distribution generation unit 4 should generate the intensity distribution of the spatial frequency component from the inspected image 55 acquired in step S101. Obtained from an external inspection range input unit (not shown) or set by itself. In the example of FIG. 5A, an inspection line 56 that is a one-dimensional region on the inspection image 55 is defined as the inspection range.

In step S <b> 104, the spatial frequency component intensity distribution generation unit 4 determines the spatial frequency in the inspection range acquired or set by the inspection range acquisition / setting unit 5 out of the inspection image 55 acquired by the inspection image acquisition unit 2. Generate an intensity distribution of components.
The spatial frequency component intensity distribution generation unit 4 may generate an intensity distribution of the spatial frequency component regarding the luminance information and brightness information of the image to be inspected. The spatial frequency component intensity distribution generation unit 4 applies a wavelet transform, a Fourier transform, or a discrete waveform to a waveform indicating a change in luminance (or brightness) accompanying a change in position of an image signal (image data) of an image to be inspected in the inspection range. By performing cosine transform, an intensity distribution of spatial frequency components in the inspection range of the inspection image is generated.

  For example, in the example of FIG. 5A, the spatial frequency component intensity distribution generation unit 4 has a waveform indicating a change in luminance (or brightness) accompanying a change in position of the image signal (image data) of the image to be inspected on the inspection line 56. Is subjected to wavelet transform or the like to obtain the spatial frequency component intensities at the respective positions on the inspection line 56.

Then, as shown in FIG. 5B, each position x at each position x on the inspection line 56 is set on a two-dimensional space having the position in the direction of the inspection line 56 as the first coordinate axis and the spatial frequency as the second coordinate axis. A two-dimensional intensity distribution indicating the intensity of the spatial frequency component of the frequency f is generated.
In FIG. 5B, the area displayed with a dark stippling indicates an area with a high spatial frequency component intensity, and the area displayed with white indicates an area with a low spatial frequency component intensity. The area indicated by indicates an intermediate intensity area. The same applies to the spatial frequency component intensity distributions shown in FIGS. 6B and 7B below.

  In step S105, the determination unit 6 obtains an intensity distribution region R in which the spatial frequency component intensity exceeds the first threshold T1 within the spatial frequency range fw acquired in step S102 among the intensity distributions generated in step S104.

Next, in step S106, the determination unit 6 determines whether or not the size of the intensity distribution region R is greater than the second threshold T2.
Since the spatial frequency range fw is a frequency range including the spatial frequency of the repeated pattern of the captured image appearing in the winding portion of the non-defective coil, if the winding of the coil 50 to be inspected is wound well, Since a similar repetitive pattern appears in the captured image of the inspection coil 50 and the spatial frequency components are collected in the spatial frequency range fw, the size of the intensity distribution region R is also increased.

  Therefore, when the magnitude of the intensity distribution region R is equal to or smaller than the second threshold T2, the determination unit 6 determines that the inspected coil 50 is a defective product (S109). On the contrary, the determination unit 6 proceeds to the next determination step S107 when the magnitude of the intensity distribution region R is larger than the second threshold value T2, but when the determination is simply performed, the coil 50 to be inspected is a non-defective product at this stage. You may determine that there is.

  As illustrated in FIG. 5B, when the inspection line 56 of the one-dimensional region is defined as the inspection range and the spatial frequency component intensity distribution is generated as the two-dimensional intensity distribution, the magnitude of the intensity distribution region R is large. The area of the two-dimensional region R may be used.

In step S107, the determination unit 6 determines whether the size of the edge of the intensity distribution region R is smaller than the third threshold T3.
If the winding of the coil 50 to be inspected is wound up well and there is little variation in the line of windings, the spatial frequency component appearing in the spatial frequency range fw is concentrated at one point, so that the intensity distribution region R Approaches a circle or sphere. Therefore, the ratio of the edge size to the size of the distribution region R itself is reduced.

  Therefore, when the edge size of the intensity distribution region R is smaller than the third threshold T3, the determination unit 6 determines that the inspected coil 50 is a non-defective product (S108). On the other hand, the determination unit 6 determines that the inspected coil 50 is a defective product when the size of the edge of the intensity distribution region R is equal to or greater than the third threshold T3 (S109).

  As illustrated in FIG. 5B, when the inspection line 56 of the one-dimensional region is defined as the inspection range and the spatial frequency component intensity distribution is generated as the two-dimensional intensity distribution, the edge of the intensity distribution region R The size of may be the length of the outer periphery of the two-dimensional region R.

FIG. 6A is a first example of an image to be inspected of a defective coil, and FIG. 6B is a diagram showing the spatial frequency component intensity distribution.
As shown in the image to be inspected in FIG. 6A, the line array of the winding 51 is greatly disturbed, so that the spatial frequency components are not collected in the spatial frequency range fw in the intensity distribution of FIG. The magnitude of the intensity distribution region R exceeding the threshold value T1 (in this example, the area of the region R) becomes very small.
Therefore, in the example of the inspected image in FIG. 6A, it is possible to determine the quality of the inspected coil by comparing the size of the intensity distribution region R with the predetermined threshold T2.

FIG. 7A is a second example of an inspected image of a defective coil, and FIG. 7B is a diagram showing the spatial frequency component intensity distribution.
The defective coil in FIG. 7A has less disturbance in the line array of the winding 51 than the defective coil in FIG. Accordingly, in the intensity distribution of FIG. 7B, spatial frequency components are also collected in the spatial frequency range fw, and the intensity distribution region R exceeding the predetermined intensity threshold T1 has a certain size, so that the intensity distribution region R It becomes difficult to determine whether the quality is good or bad.

  However, in the intensity distribution of FIG. 7B, the shape of the intensity distribution region R is distorted or split compared to the intensity distribution of FIG. For this reason, the outer peripheral length of the region R, which is the size of the intensity distribution region R, is larger than the outer peripheral length of the region R of the intensity distribution in FIG.

  Therefore, in the example of the image to be inspected in FIG. 7A, it is possible to determine the quality of the inspected coil by comparing the size of the outer peripheral length, which is the edge of the intensity distribution region R, with the predetermined threshold T3. is there.

  The inspected image acquisition unit 2 may be realized as an interface for acquiring the image signal (image data) of the inspected image from the image capturing unit 100, and is imaged by the image capturing unit such as a flexible disk and a CD-ROM. You may implement | achieve as a data input / output means which can read the image data of the to-be-inspected image memorize | stored in the recording medium. Furthermore, the coil pass / fail determination apparatus 1 may include an imaging unit that provides an inspection image to the inspection image acquisition unit 2, and may acquire the inspection image by the imaging unit.

The spatial frequency range input unit (not shown) that provides the spatial frequency range to the spatial frequency range acquisition unit 3 may be realized as a user interface device for an operator to input the spatial frequency range.
The spatial frequency range input unit inputs a captured image including a winding portion of a known good coil, calculates the spatial frequency range based on the intensity distribution of the spatial frequency component included in the input image, and acquires the spatial frequency range It may be provided to part 3.

The captured image portion of the winding portion including the fine repetitive pattern includes a spatial frequency component that is slightly higher than other portions of the coil 50 and the background image portion. Therefore, the spatial frequency range input unit obtains the intensity distribution of the spatial frequency component of the captured image of the input non-defective coil, and the spatial frequency component of the captured image of the non-defective coil is most distributed in a spatial frequency region higher than a predetermined frequency. The frequency band may be calculated as a spatial frequency range provided to the spatial frequency range acquisition unit 3.
Furthermore, the coil quality determination device 1 may include such a spatial frequency range input unit.

  In addition, an inspection range input unit (not shown) that provides the inspection range acquisition / setting unit 5 with an inspection range on the inspection image (inspection line 56 in the example of FIG. 5) is displayed by the operator. It may be realized as a user interface device for inputting. The coil pass / fail determination apparatus 1 may include such an inspected range input unit.

  Further, the inspected range acquisition / setting unit 5 may set the inspected range by itself. For example, the inspected range acquisition / setting unit 5 extracts a region of the image portion of the winding unit 51 that includes a slightly higher spatial frequency component from the captured image of the inspected coil 50, and the inspected range is wound. You may set so that the area | region of the image part of the line part 51 may be included.

  Further, the inspection range set on the inspection image in step S103 may be a two-dimensional inspection region. At this time, the spatial frequency component intensity distribution created in step S104 uses the position of the two-dimensional inspection range in the first direction as the first coordinate axis, and the position of the inspection range in the second direction as the second direction. A three-dimensional intensity distribution indicating the spatial frequency component intensity of each frequency f at each position x in the two-dimensional inspection range is formed on the three-dimensional space having the coordinate axis and the spatial frequency as the third coordinate axis.

  The spatial frequency component intensity calculated at each point of the three-dimensional coordinates includes a first frequency component intensity related to the first direction of the inspection range and a second spatial frequency component intensity related to the second direction of the inspection range. Is a vector value. The three-dimensional intensity distribution created in S104 may be a scalar value distribution indicating the absolute value of each vector value.

  Further, when the two-dimensional inspection region is set as the inspection range, the size of the intensity distribution region R compared with the second threshold value T2 in step S106 may be a volume, and compared with the third threshold value T3 in step S107. The size of the edge of the intensity distribution region R may be the surface area of the intensity distribution region R.

In addition, the calculation of the spatial frequency component included in the image to be inspected, which is an image captured by the coil 50 to be inspected, and the image captured by the non-defective coil, performed in step S104 and the like is performed as follows (in this application, “ It may be calculated by “image shift method”.
That is, for each position of the captured image, a minute range of image signals (image data) including this position is compared with an image signal (image data) of the same range at a position displaced from this position by a certain shift amount. Calculate the difference. The shift amount is gradually changed, and the shift amount with the smallest difference (both image signals are most similar) is calculated as the spatial frequency in the shift direction.

  Further, in the image to be inspected, when the position and range of the image portion obtained by imaging the winding portion 51 are known in advance (for example, the relative position between the coil 50 to be inspected and the image pickup means 100 is fixed). In such a case, in step S105, the determination unit 6 acquires or sets a range including an image portion obtained by imaging the winding portion 51 in the inspection range, and within this range and the spatial frequency range fw. It is possible to determine an intensity distribution region R in which the spatial frequency component intensity exceeds the first threshold value T1 only within the inspection window.

  For example, in the examples of FIGS. 5A and 5B, FIGS. 6A and 6B, and FIGS. 7A and 7B, the determination unit 6 is a winding portion on the inspection line 56. The range Xw1 and Xw2 including the image portion obtained by imaging 51 is acquired or set, and the intensity distribution regions are only within the respective inspection windows 61 and 62, which are the ranges within the ranges Xw1 and Xw2 and the spatial frequency range fw. Find R.

In addition, the spatial frequency component distribution generation unit 4, the inspection range acquisition / setting unit 5, the determination unit 6, and the inspection range input unit sequentially change the position of the inspection range in one inspection image, from step S103 to step S103. The above-described coil pass / fail determination method may be performed for each position of the image to be inspected by repeating step S109. Thus, it is possible to improve the determination accuracy by performing the determination a plurality of times while changing the inspection range.
At this time, the inspected range acquisition / setting unit 5 may repeatedly set a plurality of inspected ranges by changing positions on the inspected image.

  In the above description, the inspection image obtained by imaging the upper surface of the coil 50 to be inspected has been described. However, since the repeated pattern of the winding portion 51 of the coil 50 appears in the captured image obtained by imaging the coil side surface, the coil side surface was imaged. A captured image may be used as an inspection image.

  The coil pass / fail determination apparatus 1 and the coil pass / fail determination method according to the present invention may be used in the final step of the coil manufacturing process and used to determine the pass / fail of the manufactured coil.

It is explanatory drawing of the conventional coil quality inspection method. (A) is a side view of a non-defective coil, (B) is a silhouette image thereof, (C) is a side view (part 1) of a defective coil, (D) is a silhouette image thereof, ( E) is a side view (part 2) of the defective coil, and (F) is a silhouette image thereof. Coil pass / fail judgment device. It is a flowchart which shows the coil quality determination method which concerns on this invention. (A) is an inspected image of a non-defective coil, and (B) is a diagram showing the spatial frequency component intensity distribution. (A) is a to-be-inspected image of a defective coil (part 1), and (B) is a diagram showing the spatial frequency component intensity distribution. (A) is a to-be-inspected image (part 2) of a defective coil, and (B) is a diagram showing the spatial frequency component intensity distribution.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coil quality determination apparatus 2 ... Tested image acquisition part 3 ... Test range acquisition / setting part 4 ... Spatial frequency acquisition part 5 ... Spatial frequency component intensity distribution generation part 6 ... Determination part 50 ... Coil 51 ... Winding part 100 ... Imaging means

Claims (5)

Obtain a captured image of the inspected coil that is the inspected image,
Obtain the spatial frequency range including the spatial frequency component that appears in the captured image of the non-defective coil,
Calculating the intensity of each spatial frequency component of the luminance change on the predetermined line in the inspected image at each position on the predetermined line;
An intensity region that is an area in which the intensity of the spatial frequency component exceeds a predetermined first threshold in the acquired spatial frequency range on the space having the spatial frequency direction and the position direction on the predetermined straight line as coordinate axes, respectively. Decide
Determining whether the area of the intensity region exceeds a predetermined second threshold;
A coil pass / fail determination method in which when the area of the intensity region exceeds the predetermined second threshold, the coil to be inspected is determined to be non-defective. It is further determined whether or not the outer peripheral length of the intensity region is smaller than a predetermined third threshold,
When the area of the intensity region exceeds the predetermined second threshold and the outer peripheral length of the intensity region is smaller than the predetermined third threshold, the coil to be inspected is determined to be non-defective,
The area of the intensity region is equal to or less than the predetermined second threshold value, or the coil to be inspected is determined to be defective when the outer circumference length of the intensity region is equal to or greater than the predetermined third threshold value. The coil pass / fail judgment method according to 1. A coil manufacturing method, wherein the quality of a manufactured coil is determined using the coil quality determination method according to claim 1 . An image to be inspected which is an image to be inspected, an image to be inspected to acquire an image to be inspected, and a spatial frequency range acquiring unit to acquire a spatial frequency range including a spatial frequency component appearing in the imaged image of the non-defective coil;
A spatial frequency component intensity calculator that calculates the intensity of each spatial frequency component of the luminance change on the predetermined line in the inspection image at each position on the predetermined line;
An intensity region that is an area in which the intensity of the spatial frequency component exceeds a predetermined first threshold in the acquired spatial frequency range on the space having the spatial frequency direction and the position direction on the predetermined straight line as coordinate axes, respectively. And determining whether or not the area of the intensity region exceeds a predetermined second threshold, and when the area of the region exceeds the predetermined second threshold, the coil to be inspected is a non-defective product A determination unit for determining;
A coil pass / fail judgment device comprising: The determination unit further determines whether or not an outer peripheral length of the intensity region is smaller than a predetermined third threshold;
When the area of the intensity region exceeds the predetermined second threshold and the outer peripheral length of the intensity region is smaller than the predetermined third threshold, the coil to be inspected is determined to be non-defective,
The area of the intensity region is equal to or less than the predetermined second threshold value, or the coil to be inspected is determined to be defective when the outer circumference length of the intensity region is equal to or greater than the predetermined third threshold value. 4. The coil pass / fail judgment device according to 4.

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