JPH0431974A - Defect inspecting device for rectangular member - Google Patents

Abstract

PURPOSE:To perform inspection with high efficiency and accuracy by discriminating the normal/defective condition of a member to be inspected by comparing an area obtained by setting a pair of line areas intersecting orthogonally to each other with the area obtained by setting a plane area for a binary image obtained by image-picking up the member to be inspected. CONSTITUTION:A chip resistor 12 introduced to an inspection position is image- picked up by an image pickup device 11, and an input image is binarized, and is stored in image memory 23. A CPU 25, after measuring the number (l, w) of black picture elements of a binary image located at first and second line windows 32, 33, performs an arithmetic operation of S' = l X w, and finds the area S' of a body part 29. The CPU 25 measures the number S of black picture elements of the binary image included in a rectangular window 34. The CPU 25 discriminates the coincidence/noncoincidence of the measured values S' and S. Both measured values S' and S show noncoincidence when a defective part such as a pin hole 36, etc., exists in the chip resistor 12.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an inspection device used for inspecting small, rectangular electronic components such as chip resistors and chip capacitors. This is the type of chipped or pinhole shaped part.

The present invention relates to a rectangular member defect inspection device suitable for inspecting defects such as clutter.

<Prior art> For example, a chip resistor 1 has a rectangular flat plate-like appearance as shown in FIG.
It is equipped with When judging the quality of such a chip resistor 1 from its appearance, it is sufficient that the overall shape is approximately rectangular and flat, with some tolerance in the vertical and horizontal dimensions. However, if the main body part 5 has a pinhole 5 as shown in FIG. 7 or if the peripheral edge is missing, it is necessary to precisely extract this as a defective product.

<Problems to be Solved by the Invention> Conventionally, inspection of such small and rectangular electronic components has been performed manually, which requires skill and has low inspection work efficiency. , there are problems such as the test results vary depending on the inspector.

This invention is intended to solve the above problem,
In particular, it is an object of the present invention to provide a defect inspection device for rectangular members that can perform efficient and highly accurate automatic inspection of defects in rectangular members.

<Means for Solving the Problems> The present invention is a defect inspection device for a rectangular member that has an imaging section and an image processing section, and the imaging section is located directly above the member to be inspected. Capture the entire image.

The image processing section includes a binarization means and a first . The second area setting means and the first area setting means. It has a second area measuring means and a defect determining means. The binarization means binarizes the input image obtained by the imaging unit to generate a binary image.

The first region setting means sets a pair of mutually orthogonal line regions on the binary image. The second area setting means sets a plane area including the entire image for the binary image. The first area measuring means calculates the number of constituent pixels of the inspected member located on each line area, and measures the area of the image portion of the inspected member from the product of each pixel number. The number of constituent pixels of the inspected member included in the region is measured as the area of the image portion of the inspected member. The defect determination means is the first one. The measurement results obtained by each of the second area measuring means are compared to determine the quality of the inspected member.

<Operation> If the inspected member is a good product, the first. The measured values by each of the second area measuring means match, or if the product is defective, the measured values do not match. Therefore, it is possible to easily judge whether the inspected parts are good or bad depending on whether the remeasured values match or not.
Highly accurate automatic inspection with high inspection efficiency is possible.

<Embodiment> FIG. 1 shows the external appearance of a defect inspection apparatus 11 for small parts according to an embodiment of the present invention.

The illustrated small component is a chip resistor 12 having a rectangular planar shape, and each chip resistor 12 is housed in an individual housing hole 13 formed in a strip 15 for inspection. Each housing hole 13 is formed into a planar rectangular shape into which the entire chip resistor 12 fits, so that the inclination and displacement of the chip resistor 12 within the housing hole 13 is restricted.

The strip 15 is being conveyed in the direction of the arrow 16 in the figure, and when the chip resistor 12 reaches the inspection position, the conveyance operation is stopped and the inspection is performed. A plurality of positioning holes 14 are provided in the band-shaped body 15 in a line at equal intervals, and the stop position can be controlled using the positioning holes 14.

An imaging device 19 is placed directly above the inspection position, and illumination devices 17 and 18 are placed on both sides of the inspection position, and each illumination device L7, 1B illuminates the chip resistor 12 to be inspected from a substantially horizontal direction. irradiated. An optical image of the chip resistor 12 due to such illumination is captured by an imaging device 19,
The image signal is taken into the image processing device 20 and subjected to predetermined processing such as binarization, and the binary image is displayed on the display device 21.

FIG. 2 shows a schematic configuration of the image processing device 20. As shown in FIG.

In the figure, an analog image signal from an imaging device 19 is input to an image processing device 20, binarized by a binarization circuit 22, and stored in an image memory 23. This binary image is displayed on a display device 21 such as a CRT via a CRT interface circuit 24. The CPU 25 that controls such operations is connected to the image memory 23 via the pass line 26.
The path line 26 is connected to a ROM 27 in which programs for inspecting components are stored, and a RAM 28 in which various data are stored.

FIG. 3 shows a binary image 31 stored in the image memory 23.

This binary image 31 includes an object portion 29 made of black pixels and a background portion 30 made of white pixels. Second line window 32.33 (shown in Figure 3 (1))
and a rectangular window 34 (shown in FIG. 3(2)) including the object portion 29 are set, and a component inspection to be described later is executed. In this embodiment, the line windows 32, 33 have their line width set to one pixel.

FIG. 4 shows the testing procedure according to this embodiment. First, in step 1 in the figure (indicated by rsT I J in the figure), the chip resistor 12 guided to the inspection position is connected to the imaging device 1.
1, and in the next step 2, the input image is binarized and stored in the image memory 23. Next, in step 3, the CPU 25 first sets a first line window 32 for this binary image and determines the number of black pixels located on the line window 32, that is, the length l in the vertical direction of the object portion 29. Measure.

Next, the CPU 25 sets the second line window 33 in step 4 and similarly measures the lateral length W of the object portion 29, and then calculates the following equation 0 in step 5 to determine the object portion 29. Find the area S' of 29.

S' = ffiXw...■ Next, in step 6, the CPU 25 sets a rectangular window 34 for the binary image, and displays the window 34.
The number of black pixels contained in the object part 29 of the direct image
Measure the area S.

Thus, in step 7, the CPU 25 determines whether the measured value S' of step 5 and the measured value S of step 6 match. These two-point measurement values s', s are based on the chip resistor 12 in the binary image of the chip resistor 12 as shown in FIGS. 5(2) to 5(6). If a defective location such as a crack 38 exists, there is no match, and if there is no defective location as shown in FIG. 5(1), there is a match.

As a result, if step 7 is "YES", it is determined that the product is non-defective, and a determination to that effect is outputted in step 8. Further, if the result in step 7 is ``NO'', it is determined that the product is defective because it has any of the defective parts described above, and a defect determination to that effect is output in step 9.

In this way, the quality inspection of small rectangular components such as the chip resistor 12, which was conventionally done manually, is now automatically done using an image processing device, which solves the problems of the conventional technology in terms of inspection efficiency and accuracy. is resolved. In addition, since the pass/fail judgment is made by comparing the area S' obtained using the line windows 32 and 33 with the area S obtained using the rectangular window 34, there is an error in the length of the chip resistor 12 in the vertical and horizontal directions. Even if the object part 29 of the image is tilted by an angle θ with respect to the line window 32 as shown in FIG. If θ is close to zero, the error in the area S' measured in step 5 can be ignored, and the above-described process is established.

In step 7 of FIG. 4, the areas S's are compared and the quality of the parts is judged based on whether they match or do not match.
However, the present invention is not limited to this, and if the calculated value C of the following equation is less than or equal to a predetermined reference value, a good judgment may be made, and if it is greater than the reference value, a bad judgment may be made.

Further, although the above embodiment is for testing the quality of the chip resistor 12, it can also be applied to testing other electronic components or items other than electronic components as long as the planar shape is rectangular.

<Effects of the Invention> As described above, the present invention sets the area and surface area of the image obtained by setting a pair of mutually orthogonal line areas on a binary image obtained by imaging a member to be inspected. Since the quality of the inspected part is determined by comparing the area of the image obtained by This enables efficient and highly accurate inspection.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the external appearance of a defect inspection device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of the image processing device, and FIG. 3 is a binary image and FIG. 4 is a flowchart showing the operating procedure of this embodiment. FIG. 5 is an explanatory diagram showing binary images of non-defective and defective products. FIG. 6 is a diagram showing the case where the image is tilted. The explanatory diagram shown in FIG. 7 is an oblique view showing the shape of the chip resistor. 11...Inspection device 12...Chip resistor 19...Imaging device 20...Image processing device 22...Binarization circuit 23...Image memory 25... CPU

Claims (1)

[Scope of Claims] A rectangular member defect inspection device having an imaging section and an image processing device, the imaging section being located directly above the inspected member and capturing an image of the entire inspected member, and performing image processing. The section includes a binarization means, first and second area setting means, first and second area measurement means, and a defect determination means, and the binarization means includes a binarization means that detects the area obtained by the imaging section. The input image is binarized to generate a binary image, the first region setting means sets a pair of mutually orthogonal line regions on the binary image, and the second region setting means sets a pair of line regions perpendicular to each other on the binary image. On the other hand, a surface area including the entire image is set, and the first area measuring means calculates the number of constituent pixels of the inspected member located on each line area, and calculates the area of the image portion of the inspected member from the product of each pixel number. The second area measuring means measures the number of constituent pixels of the inspected member included in the surface area as the area of the image portion of the inspected member, and the defect determination means measures each of the first and second areas. A defect inspection device for a rectangular member that compares measurement results by a measuring means to determine the quality of the inspected member.