JPH067110B2 - How to detect dirt on a container - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for automatically inspecting a transparent or translucent container. This is to easily select non-defective containers that do not affect the strength.

As a typical example of the transparent or translucent container, an ampoule agent is given, which will be described below.

(Prior Art) In the ampule formulation process, a liquid agent or a solid agent is filled, and the opening of the head of the ampoule is heat-sealed with a gas burner or the like to produce the ampoule agent. , The splash of the filling liquid from the filling nozzle splashes, the tip of the filling nozzle contacts the inner wall of the ampoule head, or the filling liquid jumps up due to the gas pressure at the time of gas replacement just before the melting and closing. The liquid agent adheres to the inner wall above the surface of the ampoule, which is often carbonized by the heat generated during the melting and closing, causing charring on the inner wall of the ampoule head.

Conventionally, the detection of scorching on the inner wall surface of the ampoule, stains adhering to it, and foreign matter was made by placing a white plate on the background of the ampoule and visually inspecting it with a fluorescent lamp from above. However, there is a drawback in that it is often influenced by skill and feeling, detection accuracy is low, and it is inefficient because it is done manually.

Therefore, in order to solve these drawbacks, a method for performing efficient detection from visual inspection in the conventional detection was created (Japanese Patent Application No. 59-62663). It projects a ray of light on a transparent or semi-transparent container to be inspected, and at the same time combines the image of the transmitted light and the image of the reflected light to cancel the effect of scratches on the surface of the container to be inspected and This is a method of detecting a defective container, which detects the image of burnt charcoal or dirt that has adhered.

In this method, the light from the light source is first transmitted through the diffuser plate and projected onto the ampoule, and the transmitted light with the white light transmitted through the ampoule as the background is projected onto the light-receiving surface, resulting in black shadows due to scorching or dirt. Is projected onto the light-receiving surface, and this projected image is detected by the optical sensor. At this time, scratches on the wall surface of the ampoule agent appear as a black projected image like the image of scorching and dirt. It is difficult to distinguish between scorching, stains, and scratches only by processing the electric signal obtained by converting the black projected image.

In this case, the scratches and bubbles are generated when the dough tube of the ampoule itself is manufactured and are not dirty, so it can withstand use as a good product ampoule agent, and its amount is about 5 to 15% of the good product ampoule product. Is.

Therefore, it is necessary to distinguish this from a defective product such as scorching or stains.

Therefore, the light from the second light source is projected onto the ampoule agent in order to eliminate the effect of the image due to scratches and bubbles on the surface of the ampoule agent, which is not scorched or dirty, and to detect and select only those that have scorched or dirt. By projecting the reflected light on the light receiving surface and superimposing the projected image on the projected image of the transmitted light of the ampoule agent from the first light source, the influence of scratches due to the transmitted light is eliminated, and scorching or stains occur. Only the projected images of are detected and selected.

(Problems to be Solved by the Invention) However, the foam scratches generated in the glass wall are generated at the time of manufacturing the glass tube, and they are stretched at the time of manufacturing the ampoule, and are relatively elongated scratches in a vertical shape. It becomes a large foam scratch. As mentioned above, these are not dirt,
Moreover, since it does not impair the glass strength, it can be used as a non-defective ampoule, and in many cases it can be used as a non-defective ampoule even with considerably large scratches. However, such relatively large scratches that can be judged as non-defective products have a high light reflectance, so even if the reflected light and the transmitted light are combined, they will not cancel each other out, and the effect of the reflected light will remain, resulting in a defect. It is judged as a defective product that exceeds the judgment level.

Therefore, the technical problem of the present invention is to accurately determine an ampoule having a relatively large foam scratch or scratch that can be used as a non-defective ampoule as a non-defective article, and reliably detect only an ampoule with scorching or dirt as a defective article. The technical means of the present invention for solving this technical problem are as follows.

(Means for Solving the Problems) That is, by projecting a light beam onto a transparent or semi-transparent container to be inspected and simultaneously combining an image formed by the transmitted light and an image formed by the reflected light, the scorched charcoal attached to the container to be inspected In the method of detecting an image of dirt such as a stain, a composite signal is formed by converting an electric signal obtained by receiving the images of reflected light and transmitted light into an AC signal and reversing the positive / negative, and the negative polarity of the composite signal is detected. After the signal is generated, by adding a negative voltage for a certain period of time to the composite signal, the positive polarity signal following the negative polarity signal is cut, and the damage due to scratches on the surface of the container to be inspected or the effect of foam scratches is canceled to the container. This is a method of detecting the adhered dirt.

(Effects of the Invention) According to this technical means, by combining transmitted light and reflected light, it is possible to cancel the influence of scratches, bubble scratches, and the like on the surface of the container to be inspected, and detect only the scorching and dirt. It is possible to implement the characteristic of 1 with higher sensitivity.

Convert the projected image of reflected light and transmitted light for dirt such as scorching and large and small scratches from the DC signal waveform (waveform of DC signal) to the AC signal waveform (waveform of AC signal with positive and negative inversion) (that is, differentiate it) ) When the waveform shapes are compared, the results are shown in Table 1 below.

X in Table 1 is a signal waveform that has a small degree of scratches and may be determined as a non-defective container. Y is a signal waveform due to scorching and dirt, and is a signal waveform determined to be a defective container. Z is a signal waveform that can be judged as a non-defective container although the degree of scratches is large. Table 1 shows the reflected light and the transmitted light of X, Y, and Z respectively having a DC waveform and an AC waveform, and a combined signal obtained by combining the reflected light and the transmitted light.

When judging good or bad, it is difficult to set the reference level because the DC waveform has a small change and the height of the base voltage is not constant. Therefore, the judgment of the AC waveform that captures the voltage change amount is made. A predetermined defect judgment reference level (indicated by a broken line in the table) using the combined signal from the combinations
To compare with.

Comparing the AC waveforms of each composite signal, if the signal strength is adjusted so that the balance of the reflected light rate and the transmitted light rate is the same for X, which has only small scratches or foam scratches, the reflected light will be reflected in the case of scorching or dirt of Y. Since there is almost no light, only the projected image due to the transmitted light is present, and conversely, in the case of a bubble scratch or a scratch having a large Z scratch, the influence of the reflected light becomes large. Therefore, since the waveform of the unevenness is canceled and disappears in X, it is judged as a good product regardless of the judgment reference level, and Y is judged as defective because it exceeds the defect judgment level, and Z is a non-defective product because the influence of reflected light remains. Despite the ampoule that should be taken, it is judged as defective.

Therefore, in the case of Z, when the reflected light and the transmitted light are combined with each other to cancel each other out, and the unevenness of the waveform of the combined signal disappears, adjustment is made by strengthening the light source of the transmitted light. The transmitted light of (1) appears as a large waveform and is determined to be defective, and X and Z cannot be deleted from the determination of defective by the balance adjustment of the reflected light and the transmitted light.

However, the present invention pays attention to the difference in the polarity of the waveform of the scorching signal and the waveform of the signal of the bubble scratch having a high reflected light rate, and by using the method of separating both, X and Z are determined to be non-defective products, Only the burnt charcoal of Y can be determined as a defective product, and the characteristic is that extremely accurate and efficient detection can be performed.

(Example) Hereinafter, the Example of this invention is described.

First, the means for projecting the combined light and the reflected light on the ampoule according to the present invention will be described. FIG. 3 shows an ampoule (a) whose head (1) has an opening (2) at the upper side. The filling nozzle is inserted from this opening (2) to fill the chemical liquid. At that time, the splash of the filling liquid from the filling nozzle is scattered or the tip of the filling nozzle touches the inner wall. Alternatively, when the gas is replaced immediately before the melt-sealing, the chemical liquid adheres to the inner wall due to the splashing of the filling liquid due to the gas pressure, etc., and when this melts and seals in the opening (2), the charring occurs.

Therefore, in order to detect the scorching or stain of the ampoule agent (A), a diffusing plate (7) such as glass is rubbed from the light source (6) to the ampoule agent (A) as shown in FIG. Diffuse light is projected through it, and this transmitted light is projected through the imaging lens (8) onto the light-receiving surface of the optical sensor (9), and the black image of scorching or dirt due to this projection is converted into an electrical signal. Then, this is processed and detected by the processing circuit (10). At this time, since the projection light for the ampoule agent is diffused by the diffuser plate (7), the light is evenly projected on the ampoule agent (A), and the background for the ampoule agent (A) becomes white light, which is scorched or black with stains. You can catch all the shadows.

What is shown in FIG. 5 is that the light projected onto the ampoule agent (A) is a parallel light beam transmitted from the light source (6) through the light projecting lens (11), and also shown in FIG. The light emitted from the light source (6 ') to the ampoule (A) is reflected by the reflector (1
2). In FIG. 6, the light source (6 ') for the reflected and transmitted light by the reflection plate (12) also serves as the light source for the directly reflected light.

In this way, the transmitted light from the light source (6) or (6 ') that has passed through the ampoule agent (A) is projected on the light receiving surface of the optical sensor (9) through the imaging lens (8). However, as shown in FIG. 7 (a), when limited to transmitted light, scorching and dirt (3) are projected as black shadows on the inner surface of the wall, and scratches and bubbles () of the ampoule agent (A) are present. 4)
Is also detected by the optical sensor (9) as a black shadow.

Therefore, in order to eliminate the image of the black shadow due to the scratches and bubbles (4), a second light source (13) for projecting light from a direction different from the straight transmitted light from the light source (6) is provided and projected. The light is passed through the optical lens (14) and projected onto the ampoule (A), and the reflected light is transmitted through the imaging lens (8) and projected onto the light receiving surface of the optical sensor (9) for detection. There is.

Since this reflected light is the light reflected by the object, the scratches and bubbles (4) on the light receiving surface of the optical sensor (9), as shown in FIG. It becomes bright and projected white.

As described above, the optical sensor (9) simultaneously captures the image of the transmitted light and the image of the reflected light with respect to the ampoule agent (A).
When it is projected on the light-receiving surface of, the scratches and bubbles (4) disappear without black shadow, as shown in Fig. 7 (C).
Burnt marks and dirt (3) remain as a black image. This image is detected by the optical sensor (9) and converted into an electric signal, and the change in the level of this signal is processed by the next processing circuit (10). The ampoule agent (A) detected by this processing is ，
It is being rejected from the manufacturing process as a defective product.

As shown in FIG. 8, the light-receiving surface of the optical sensor (9) has a light-receiving portion (5) that is finely divided in the vertical direction, and this light-receiving portion (5) is the head of the ampoule agent (A) ( At the center of the projected image of 1) in the vertical direction, while rotating the ampoule agent (A), the light receiving unit (4) detects this projected image so that the entire head (1) is inspected. Has become.

Now, FIG. 1 is a block diagram showing a circuit (10) for processing a signal from the optical sensor (9).

An amplifier (15) converts the change in the current on the light-receiving surface of the optical sensor into a voltage to generate an electric signal, and then a DC-AC converter (16) and an inverting amplifier (17) convert the DC signal into an AC signal.
Convert to signal. An AC signal indicating that only the AC component is extracted from the DC component is sent to the next foam flaw separation circuit (18). In the foam flaw separation circuit (18), the AC signal and the negative level determination reference signal (20) set to a constant level are applied to the comparator (19) so that the waveform of the AC signal becomes equal to or lower than the constant negative level. A comparative determination is made as to whether or not the waveform extends.

The negative polarity level determination reference signal (20) is a reference signal for detecting the negative polarity signal, but it is set to a negative polarity level slightly negative from the zero potential level to prevent erroneous determination due to an error around the zero level. I'm out.

The determination signal output from the comparator (19) is input to the negative voltage generation circuit (21), and when there is a waveform with a negative polarity level or less, a constant negative voltage (2
2) is created and mixed with the AC signal from the amplifier (17).

When the operation of this foam scratch separation circuit is viewed in the chart shown in FIG. 2, the AC signal waveform of the scorched Y has a voltage that is initially increased in the positive direction (b) and then pulled in the negative direction (c). ). On the other hand, foam scratches (hereinafter collectively referred to as foam scratches)
The AC signal waveform of Z having a large value shows a waveform that first falls in the negative direction (d) and then increases in the positive direction (e), and has a polarity opposite to that of the scorched Y.

The AC signal waveform X of a small scratch, which is a non-defective product, is canceled by the transmitted light and the reflected light and becomes a zero-level waveform.

Therefore, the present invention focuses on the difference in the polarities of the signal waveforms of the foam scratch Z and the scorching Y, and excludes the signal of the foam Z from the detection by the defective product determination signal so that only the scorching Y can be read. Specifically, processing is performed so that the positive polarity signal (e) is not read.

That is, when the negative polarity level determination reference signal (20) is applied by the comparator (19) and compared with the constant negative polarity level (1), in the case of the scorching signal waveform Y, it exceeds the (e) level ( In the case of the foam damage signal waveform Z, due to the negative voltage of c), the command signal for generating the negative voltage (22) is input to the negative voltage generating circuit (21) by the negative voltage of (d) exceeding 1 level, For example, a relatively large negative voltage such as -12V is created. In this case, since the signal waveform of X is at the zero level as described above, the negative voltage generating circuit (2
No command signal is input to 1) and no negative voltage is generated.

Next, when the negative voltage (22) and the AC signal output from the amplifier (17) are mixed, the scorched AC signal waveform Y has a negative direction constant time of -12 V from the beginning of the voltage decrease in (c). (T) The AC signal waveform Z of the foam scratch is pulled down, and similarly, the voltage signal of (d) is -1 from the beginning of the voltage drop.
Only 2V is pulled in the negative direction for a certain time (t).

Therefore, the signal waveform in which the positive direction signal that follows the negative direction signal is cut by the negative voltage and only the signal such as (b) b, which is the positive direction signal at the beginning, is left is the bubble flaw separation circuit ( 10) and input to a comparator (24), which is applied with a defective product determination reference signal (23) for determining the extent of the size of the scorching waveform and compared. Those that exceed the voltage of the defective product reference signal (23) are determined as defective products, and a good product / defective product determination signal (25) is output.

The constant time (t) in which the negative voltage (22) is applied may be such that the time for cutting the signal in the positive direction that follows the signal in the negative direction = width of the chart. Negative voltage (22)
Is an extremely large negative voltage compared to the positive and negative signal waveforms (b, c, d, e), so any positive signal in the positive direction following the signal in the negative direction can be sufficiently pulled to generate any foam scratch signal. The potential can be set to a negative potential from the zero level, so that only the scorching signal can be determined by the comparator (24).

[Brief description of drawings]

FIG. 1 shows a processing circuit (1) for carrying out the method of the invention.
0) a block diagram showing an embodiment, FIG. 2 is a chart showing its operation, FIG. 3 (a) is a sectional view of an ampoule,
(B) is a front view of the ampoule, FIG. 4 is an explanatory drawing of an apparatus for carrying out the present invention, FIGS. 5 and 6 are explanatory drawings of another example of the apparatus, and FIG. 7 is a light-receiving surface. Is a descriptive drawing of the projected view of (a) is based on the case of only transmitted light,
(B) shows the case of only reflected light, (C) shows these overlaid, and FIG. 8 is an explanatory drawing showing the relationship between the projected view and the light receiving surface. A ... Ampoule agent a ... Ampoule 1 ... Head part 2 ... Aperture 3 ... Burning, dirt 4 ... Scratches, bubbles 5 ... Light receiving part 6, 6 '... Light source 7 ... Diffusion plate 8 ... Imaging lens 9 ... Optical sensor 10 ... Processing Circuit 11 ... Projection lens 12 ... Reflector 13 ... Second light source 14 ... Projection lens 15 ... Amplifier 16 ... DC-AC converter 17 ... Amplifier 18 ... Foam scratch separation circuit 19 ... Comparator 20 ... Negative polarity level reference Signal 21 ... Negative voltage generating circuit 22 ... Negative voltage 23 ... Defective product determination reference signal 24 ... Comparator 25 ... Determination signal

Claims (1)

[Claims] 1. A transparent or semi-transparent container to be inspected is projected with a light beam, and the image of transmitted light and the image of reflected light are combined at the same time, whereby the image of dirt such as scorching on the container to be inspected is formed. In the detection method, a composite signal is formed by converting an electric signal obtained by receiving images of reflected light and transmitted light into an AC signal and reversing the positive / negative, and after a negative signal in the composite signal is generated, a constant signal is generated. By adding the negative voltage of time to the composite signal, the positive polarity signal following the negative polarity signal is cut, and the influence of scratches on the surface of the container to be inspected, foam scratches, etc. is canceled and dirt on the container is detected. Method.