JPH11218502A - Inspection apparatus for defect of article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspection apparatus by which the quality of an article can be judged correctly even when the product having an irregularity in the density of, e.g. a frosted glass is supplied. SOLUTION: An image by a camera 7A is binarized on the basis of a binarization level which is decided in advance by a binarization means 14. An inspection region is set by an inspection-region setting means 21, inside the image which is binarized by the binarization means 14. The quality of an article is judged by a judgment means 23 on the basis of the image inside the inspection region. When a frosted glass is dense, the contour region the object which is sorted to be a black pixel creeps into the inspection region so as to be judged to be a defective article. Then, by binarization-level adjusting means 19, the total number of white or black pixels obtained by the binarization means 14 is adjudged so as to agree with a preset number or reference images. Thereby, it is possible to prevent the contour part of the article as the black pixel from creeping into the inspection region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article defect inspection apparatus for inspecting, for example, the presence or absence of dirt or scratches at the tip of a syringe.

[0002]

2. Description of the Related Art Conventionally, as an article defect inspection apparatus using a camera, a camera for photographing an article and a camera for binarizing an image by the camera based on a predetermined binarization level.
Binarizing means, an inspection area setting means for setting an inspection area in the image binarized by the binarizing means, and an image of the article based on the image in the inspection area set by the inspection area setting means. There is known a device provided with a determination unit for determining pass / fail. In this type of defect inspection apparatus, the number of black or white pixels in the inspection area is counted, and when the total number of pixels is not within an allowable range, the article is determined to be defective. . More specifically, in the case of a defect inspection device for a light transmission type article, scratches and dust reflect light and become black, so when the number of black pixels equal to or greater than a predetermined amount is present in the inspection area. Can be determined to be defective.

[0003]

However, conventionally,
Since the image is binarized based on the binarization level determined in advance by the binarization means, if there is variation in the color depth or surface processing state of the article, the transmitted light image of the article Alternatively, since the brightness of the reflected light image varies, the image obtained by the binarizing means also varies from article to article, which leads to erroneous detection. For example, when the article is a syringe, the tip to which the injection needle is attached is ground glass, but when an image is obtained by transmitting light to the tip, if the ground glass is thin, the whole becomes white. A binarized image is obtained, and when the ground glass is dark, a binarized image as a whole is obtained. And especially when the ground glass is dark,
A black binarized portion easily enters a predetermined inspection area, and in this case, a certain number or more of black pixels is detected in the inspection area even if there is no scratch or dust.
The result was that the product was determined to be defective despite being good. The present invention has been made in view of such circumstances, for example, even when an article having a variation in the thickness of the ground glass is supplied,
It is an object of the present invention to provide an article defect inspection apparatus capable of correctly determining the quality.

[0004]

According to the present invention, in the above-described conventional defect inspection apparatus for articles, the binarization level of the binarization means is determined by the sum of white or black obtained by the binarization means. It is provided with a binarization level adjusting means for adjusting the number of pixels to be equal to a predetermined number of reference pixels.

[0005]

According to the above configuration, in the above-described example, when the ground glass is dark, a binarized black image is obtained as a whole, so that the total number of black pixels is large and the total number of white pixels is small. Less. Then, the binarization level adjustment means:
The binarization level in the binarization unit is adjusted, and the total number of white or black pixels obtained by the binarization unit is set so as to match a predetermined reference pixel number. That is, regardless of whether the ground glass is dark or light, the total number of white or black pixels in the image obtained by the binarizing means matches the predetermined reference pixel number. Therefore, if the number of reference pixels is set so that the black binarized portion does not enter the inspection area, the black binarized portion is inspected regardless of whether the ground glass is dark or light. It is possible to prevent entry into the area and prevent erroneous detection due to the entry. As a result, even if articles having a variation in the thickness of the ground glass are supplied, their acceptability can be correctly determined.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a syringe 1 (see FIG. 5) as an article is housed in a holder (not shown) with its tip end directed upward. The syringe 1 is carried into the article defect inspection device 4 from the conveyor 2 via the star wheel 3 while being accommodated in the holder. The article defect inspection device 4 includes a rotary table 5 that rotates in synchronization with the star wheel 3, and a plurality of rotary tables 6 provided at regular intervals on the outer peripheral portion of the rotary table 5, on each of which the holder is mounted. It has. Around the rotary table 5,
Three cameras 7A, 7B, 7C are arranged at 90-degree intervals toward the center of the rotary table 5, and each camera 7
Light sources 8 are arranged and fixed on the front surfaces of A to 7C, respectively.
The syringe 1 supplied and placed from the star wheel 3 to each turntable 6 is conveyed with the rotation of the turntable 5 with the turntable 6 stationary, and the syringe 1 is moved between the first first camera 7A and the light source 8. Is passed through. Each of the cameras 7A to 7C is
Each is taken as the syringe 1 passes over the front surface thereof. Syringe 1 is the first camera 7A
, The turntable 6 is rotated 120 degrees, and in this state, the syringe 1 passes through the front surface of the second camera 7B and is taken by the second camera 7B. And, similarly, the syringe 1 is connected to the second camera 7B.
, The turntable 6 is again moved in the same direction by 12 degrees.
After being rotated 0 degrees, it comes to rest and the syringe 1
Is passed through the front surface of the third camera 7C in this state, and is taken by the third camera 7C. The syringe 1 having passed through the third camera C is carried out onto the conveyor 2 via the star wheel 9, and the syringe 1 determined to be defective by the determination means described later is rejected by a reject device (not shown) provided on the downstream side. 2 to be discharged to the outside from above.

As shown in FIG. 2, the signal from each of the cameras 7A is converted by the A / D converter 11 into a monochrome image of, for example, 256 gradations, and the image obtained by the A / D converter 11 The correcting means 12 corrects the position so that, for example, the shoulders a and a '(see FIG. 5) become the reference positions in the predetermined inspection frame. Next, the histogram creating means 13 converts the 256 grayscale black and white image obtained by the A / D conversion means 11 into 256
A histogram is created by summing the number of generated pixels for each pixel of each gradation. Then, the binarizing means 14 selects the pixels of 256 gradations into white or black pixels based on a preset binarization level. In the illustrated embodiment, the binarizing means 14 includes a low slice level setting means 15 and a high slice level setting means 16 for setting the binarization level. As shown in FIG. Pixels brighter than the low slice level set by the setting means 15 and darker than the high slice level set by the high slice level setting means 16 are selected as white, and the other pixels are selected as black. .
In the present embodiment, the high slice level is set so that bright light directly input to the camera 7A is determined as black without passing through the syringe 1, and this set value is changed while being fixed. There is no.

Further, the binarizing means 14 includes white pixel counting means 17.
Counts the total number of white pixels selected at the binarization level. The comparing means 18 compares the predetermined number of reference pixels with the total number of white pixels counted by the counting means 17, and when they do not match, the low slice level is adjusted by the binarization level adjusting means 19. Become like More specifically, when the total number of white pixels is smaller than the reference pixel number, the row slice level is moved to the left in FIG. This increases the number of pixels that are selected as white. Conversely, if the total number of white pixels is greater than the reference number of pixels, the row slice level is shifted to the right in FIG. Decrease. The fact that the predetermined number of reference pixels matches the total number of white pixels is not limited to the fact that the numbers exactly match. As is clear from the histogram of FIG. 3, the number of pixels classified into one gradation is not necessarily one, and if the row slice level is shifted by one gradation, the total number of white pixels may vary greatly. is there. For this reason, the reference pixel number can be given a certain allowable range, or the above-mentioned match is regarded as the total number of pixels at the low slice level at which a gray level at which a white pixel closer to one reference pixel number is obtained is obtained. The above-mentioned coincidence can be regarded as the total number of pixels at the low slice level at which a gray level at which a white pixel just exceeds or does not exceed one reference pixel is obtained.

When the total number of white pixels is adjusted to match the predetermined number of reference pixels as described above, the inspection area setting means 21 then proceeds to the above-described step 2 as shown in FIG.
The inspection area 2 is included in the image binarized by the binarizing unit 14.
Set 2. At this time, as described later in detail, in a state where the total number of white pixels is adjusted to match a predetermined reference number of pixels, the inspection area 21 is originally selected as black. It is not set in the area of the black pixel along the contour of the syringe. Then, the judging means 23 detects the presence or absence of a black pixel in the inspection area 22. If a black pixel is detected, it is a scratch or dust 25, so the judging means 23 judges the syringe 1 as a defective product. It will be determined. The above-mentioned work is performed by three cameras 7A
This is performed every .about.7C, and if the determination unit 23 determines that the image from at least one camera is defective, the syringe 1 is finally determined to be defective.

In the above configuration, it is assumed that the total number of white pixels is adjusted by the row slice level shown in FIG. 3 so as to match a predetermined reference number of pixels. In this case, the outline of the syringe 1 indicated by the imaginary line in FIG. 5 is more difficult to transmit light than the center portion. Therefore, in the case of a normal syringe, only a certain width along the outline is selected as black. Otherwise, it is sorted as white. When the inspection area 22 is set in the syringe 1 in this state, the inspection area 22 is set in an area selected as white, and the inspection area 22 is selected as black. So that it does not cover the area. Therefore, after setting this state, the determination unit 23 detects the presence or absence of a black pixel in the inspection area 22. If a black pixel is detected, it is a scratch or dust 25. Can be determined.

On the other hand, when a syringe whose ground glass is darker than the above-mentioned syringe is supplied, as shown in FIG.
As a whole, an image that is binarized black as compared to the above case is obtained. That is, in FIG. 4, when the same row slice level as that in FIG. 3 is used as a reference, the number of pixels selected as white on the right side is smaller than the row slice level, and the number of pixels selected as black on the left side is larger. In this case, since the width of the black pixel in the outline portion of the syringe 1 in FIG. 5 is wide, the black portion enters the inspection area 22 and even if there is no flaw or dust, the inspection area 22 is not damaged. A certain number or more of black pixels is detected, and the result is determined as a defective product although it is a non-defective product. In this case, however, since the total number of white pixels is smaller than the predetermined number of reference pixels, the binarization level adjusting means 19 adjusts the row slice level so as to increase the number of white pixels by the arrow in FIG. And shift to the left as indicated by the imaginary line. If the row slice level is shifted to the left until the total number of white pixels coincides with the predetermined reference number of pixels, the outline of the syringe 1 is selected as black in that state, and the rest is selected as white. Become so. This state is substantially equivalent to FIG.
Therefore, the inspection area 22 is set in the area selected as white, and the outline of the syringe does not cover the inspection area 22. As a result, even if a syringe with a thick ground glass is supplied, the quality of the syringe can be accurately determined by the determination unit 23.

Since the scratches and dust 25 are classified as black pixels, the number of white pixels is reduced by the presence of the scratches and dust 25.
Since the value is sufficiently larger than the number of pixels according to 5, the presence of the scratches and dust 25 does not adversely affect the setting of the row slice level. FIG. 4 illustrates an example in which the ground glass is darker than that in FIG. 3. However, when the ground glass becomes thinner, it is apparent that the row slice level may be shifted in reverse. In the above embodiment, the total number of white pixels is used as a reference, but the total number of black pixels may be used as a reference. Further, the article to be inspected is not necessarily limited to a syringe, and it goes without saying that the present invention can be applied to other articles. Although the high slice level is fixed in the above embodiment, the low slice level can be fixed and the high slice level can be adjusted depending on the type of article.

[0013]

As described above, according to the present invention, for example, even if articles having a variation in the thickness of the ground glass are supplied, the quality of the articles can be correctly determined.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing one embodiment of the present invention.

FIG. 2 is a configuration diagram for explaining the present invention.

FIG. 3 is a diagram illustrating an example of a histogram obtained by a histogram creating unit 13 in FIG. 2;

FIG. 4 is a diagram showing another example of a histogram obtained by the histogram creating means 13;

FIG. 5 is an explanatory diagram for explaining a state of image processing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Syringe (article) 4 ... Defect inspection apparatus 7A, 7B, 7C ... Camera 8 ... Light source 11 ... A / D conversion means 13 ... Histogram creation means 14 ... Binarization means 15 ... Low slice level setting means 16 ... High slice Level setting means 17 ... Counting means 18 ... Comparing means 19 ... Binary level adjusting means 21 ... Inspection area setting means 22 ... Inspection area 23 ... Determining means

Continued on the front page (72) Inventor Koji Yamada 1-3-45, Kurakinai, Ibaraki-shi, Osaka Sumitomo Pharmaceutical Co., Ltd. Ibaraki Plant (72) Inventor Yo Yotsuki 1-3-45, Kurakinai, Ibaraki-shi, Osaka Sumitomo Pharma Co., Ltd. (72) Inventor Shuji Onaka 1-1-25 Shinurashima-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Within NEC Corporation (72) Inventor Satoshi Watanabe 1-1-1, Shinurashima-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture 1-25 Inside of NEC Robot Engineering Co., Ltd. (72) Inventor Ichiro Hamano 58, Kozudahonmachi, Kanazawa-shi, Ishikawa Prefecture Inside Shibuya Kogyo Co., Ltd.

Claims (6)

[Claims] 1. A camera for photographing an article, a binarizing unit for binarizing an image by the camera based on a predetermined binarization level, and an image in the binarized image by the binarizing unit. A defect inspection apparatus for an article, comprising: an inspection area setting means for setting an inspection area in the inspection area; and a determination means for determining acceptability of the article based on an image in the inspection area set by the inspection area setting means. A binarization level adjusting unit for adjusting a binarization level of the binarization unit so that the total number of white or black pixels obtained by the binarization unit matches a predetermined reference pixel number; An article defect inspection apparatus characterized by the following. 2. A defect inspection apparatus for an article, comprising: a conversion circuit for converting an image obtained by a camera into a black and white image having a large number of gradations;
Histogram generating means for generating a histogram indicating the number of pixels generated for each gradation from the image obtained by the conversion circuit, wherein the binarization means converts each gradation of the histogram to white based on the binarization level. 2. The article defect inspection apparatus according to claim 1, wherein the article is binarized into black. 3. The binarizing means counts white or black pixels obtained based on the binarization level to obtain a total number of pixels, and a total number of pixels obtained by the counting means. 3. The article defect inspection apparatus according to claim 1, further comprising: a comparison unit configured to compare the reference number of pixels with a predetermined number of reference pixels. 4. The binarization level includes a row slice level for selecting a pixel darker than the level as black and a bright image as white, and the binarization level adjusting means adjusts the row slice level. The article defect inspection apparatus according to any one of claims 1 to 3, wherein: 5. The article defect inspection according to claim 4, wherein the binarization level includes a high slice level for selecting a pixel darker than the level as white and a bright image as black. apparatus. 6. The article is a syringe having a ground glass tip at which a syringe needle is attached, and wherein the defect inspection apparatus for the article inspects the tip for defects. An article defect inspection apparatus according to any one of claims 1 to 5.