JPS58743A - Flaw inspecting device - Google Patents

Abstract

PURPOSE:To prevent from hasted misjudge that assuming a defective product as a nondefective one, when a body to be inspected is not rotated, by providing a circuit for detecting a rotation in addition to a flaw detecting circuit of the body to be inspected which is rotated and shifted, and executing a decision in accordance with a result of detection by both the circuits. CONSTITUTION:A cylindrical body 4 such as a medicine capsule, etc. is rotated and driven by a rotary roller 5, is illuminated by illuminating devices 2, 3, a reflected ray is photodetected by a photoelectric sensor 1, is converted to an electric signal, and is inputted to a flaw detecting circuit 7 and a rotation detecting circuit 8. The circuit 7 detects whether a flaw exists or not, the circuit 8 detects whether a rotation exists or not, and said each result is inputted to an overall deciding circuit 9. The circuit 9 decides an output of the flaw detecting circuit 7 as effective only wnen a rotation exists, and decides it as a defective when both a rotation and a flaw exist. Therefore, since a part having a flaw is not photodetected when a body to be inspected is not rotated, it is prevented from heated misjudge that assuming a defective product as a non-defective unit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flaw inspection device that optically performs a helical scan on a cylindrical object such as a drug capsule to inspect the presence or absence of flaws.

FIG. 1 (1) is a perspective view showing a conventional flaw inspection device operating normally. In the figure, a cylindrical object 4, which is an object to be inspected, is a rotary rotor rotating in the direction of arrow B. 5 and is being sent in the direction indicated by the arrow while being rotationally driven. On the other hand, the cylindrical object 4 is irradiated with light from the illumination device 2.3, and a reflected wave from one point on the cylindrical object 4 is input to the photoelectric center tlK, where it is converted into an electrical signal. That is, it can be said that the output signal obtained from the photoelectric sensor 1 is a signal obtained as a result of helical scanning around the cylindrical object 40.

The waveform of the output signal obtained from the photoelectric sensor f1 after 5K is as follows: If there is a flaw P such as a pinhole around the cylindrical object 40, the amount of light reflected from that part will be the same as the amount of light reflected from other normal parts. Since it is very small compared to the amount of light,
The first wA(b)K becomes as shown. In other words, Fig. 1~)K
A change point P' in FIG. 1 indicates an output change caused by the flaw PK on the cylindrical object 4.

Therefore, if we differentiate the output signal from photoelectric sensor +1, we find that the first
An output waveform shown in Figure (C) K is obtained, making it easy to detect the signal change P' corresponding to the flaw PK. If there are no scratches around the cylindrical object 40, such a signal change P' will not be detected, so that the cylindrical object is determined to be a J1 product without any scratches.

However, in conventional flaw inspection devices, the rotating roller 5 that is supposed to drive the cylindrical object does not rotate due to a malfunction, or the cylindrical object 4 does not rotate because it has an irregular shape, as shown in FIG. 2 (1). In this case, even if the cylindrical object 4 passes in the direction indicated by the arrow, the entire area around the cylindrical object is not inspected by helical scanning.

However, the output signal of the photoelectric sensor 1 has a flat waveform with no abnormality as shown in FIG. 2(b), and therefore its differential output does not include any signal change as shown in FIG. # The trap of not fully inspecting the periphery of the cylindrical object is that there is a risk that the cylindrical object may be determined to be a defective item with conventional flaw inspection equipment.

The present invention has been made to eliminate the drawbacks of the conventional flaw inspection apparatus as described above, and therefore, an object of the present invention is to remove the cylindrical flaw inspection device, which is an object to be inspected, even though the rotating roller is not rotating. To provide a flaw inspection device that does not quickly judge objects as non-defective.

The main point of the configuration of the present invention is that in addition to a circuit for detecting the presence of flaws on the object to be inspected, a circuit for detecting the presence or absence of rotation of the object to be inspected is provided, and the detection results of both sides are used to determine whether the object to be inspected is good or bad. The point is that the structure is configured to perform the determination.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram showing one embodiment of the present invention.

In the figure, 6 is a signal amplification amplifier, 7 is a flaw detection circuit, 8 is a rotation detection circuit, 9 is a general judgment enclosure, 10 is a defective product discharge section, and 11th m! , the same i as in the 2nd HK refers to the same thing.

In FIG. 3, a cylindrical object 4, which is an object to be inspected, advances while being rotated by a rotating roller 5. As shown in FIG.

A cylindrical object 4 is illuminated by illumination devices 2 and 3, and a photoelectric sensor 1 converts changes in brightness at the illuminated area into electrical signals. The output of this photoelectric sensor 1 is amplified by a signal amplification amplifier 6 and inputted to a flaw detection circuit 7 and a rotation detection circuit 8. The flaw detection circuit 7 detects the presence or absence of flaws and outputs the result to the mass storage determination circuit 9, and the rotation detection circuit 8 detects the presence or absence of 40 rotations of the cylindrical object and outputs the result to the general assembly determination circuit 9. . In the Il meeting determination circuit 9, the flaw detection circuit 7 is activated only when the output from the rotation detection circuit 6 is "rotation present".
If the output is "rotated" and "damaged", a command is issued to the LI&discharge unit 10 to discharge the IA cough cylindrical object as a defective product.

No. 41m is a circuit diagram showing a configuration example of the flaw detection circuit 7, jIs
The figure is a tie-setting chart of the strip signal in FIG. 4.

In FIG. 4, 11 is a differentiator, 12 and 13 are comparators, 14 is a tie such as a monostable multivibrator, 15 is a counter, and 16 is a digital comparator.

The operation will be explained with reference to FIGS. 4 and 5. The output signal (2) sent from the photoelectric sensor via the amplification amplifier is input to the differentiator 11 and differentiated.

If the output signal ■ contains a flaw signal as seen in FIG. 5, its differential output @ will have a waveform as shown in FIG. This differential output @ is sent to the comparator 13
When compared with a reference voltage T')-11 consisting of , and binarized, a rising signal θ as shown in FIG. 5 is obtained via an inverter I. On the other hand, the differential output @ is applied to another reference voltage TH! in the comparator 12. When compared and binarized, the fifth
A falling signal O as shown in the figure is obtained. Furthermore, when a timer 14 made of, for example, a monostable multi-wavelength circuit is operated at the falling edge of the falling signal O, a timer output as shown in FIG. 5 is obtained. When the logical product of this timer output and the rising signal θ is output from the AND gate A, this is the flaw detection signal θ as shown in FIG.
If there is a scratch such as a pinhole on the circle input to the counter 15, the amount of light reflected from that spot will decrease and the output of the photoelectric sensor will change, so this change can be detected as a scratch. It is detected by the circuit.

This flaw detection signal θ is counted by a counter 15, and the count result is compared with a reference value formed by a digital comparator 111. If it exceeds the reference value, it is determined that there is a flaw, and if it does not exceed the reference value, it is determined that there is an uneven heat. , output the result.

FIG. 6 is a circuit diagram showing an example of the configuration of the reversal detection circuit 8, 111
710 is a timing chart of each part signal in the 611th part.

In Figure 6, 17 is a differentiator, 18 is a comparator, 19 is a timer such as a monostable multivibrator, 2 is a counter, and 21 is a digital ratio I! It is a vessel.

The operation will be explained with reference to FIGS. 6 and 7. The output signal sent from the charge sensor amount via the amplification amplifier is input to the differential i117 and differentiated.

As seen in FIG. 7, this differential output @ includes level fluctuations depending on the rotational frequency of one cylindrical object due to the sway rK due to cartwheeling of the cylindrical object.

This differential output @ is converted into a reference value VTH by the comparator 18.
When compared with and binarized, a comparator output θ as shown in FIG. 7 is obtained via an inverter I.

This ratio IIRII output θ becomes a pulse train signal having a repetition frequency corresponding to the rotational frequency of the cylinder. When a timer 19 consisting of, for example, a mono T multivibrator is operated at the falling edge of each pulse of the comparator output θ, the seventh
A timer output @ as shown in the figure is obtained. The logical AND output of the timer output O and the comparator output θ is output from the AND gate A, and the input to the counter 20 is obtained as shown in the 7th mK. The counter 20 counts this human power signal, and the count result is compared with a reference value formed by a digital comparison 1121. If the reference value is exceeded, it is determined that the cylindrical object is rotating, and if it is not, it is determined that there is no rotation. Output.

As explained above, in the flaw inspection device using a single shot, flaw detection and rotation detection are performed on the cylindrical body, and only when no flaw is detected and rotation is detected, the object to be inspected is determined to be storm crystal.

Others are determined to be defective and are discharged to the defective side by the defective article discharging section 10.

According to this invention, since the rotation detection circuit is combined with the flaw detection circuit, a cylindrical object that does not rotate normally can be determined to be defective. In other words, even if the cylindrical object is crushed and does not rotate properly, the rotation detection circuit cannot detect the rotation, so it can be determined that the object is defective.

The explanation so far has been about the case where a cylindrical object made of an opaque material is inspected using a reflected light sensor, but a cylindrical object made of a transparent material can also be inspected with ease. In the case of a transparent cylindrical object, the structure of the flaw detection circuit is quite different, and the rising signal activates a timer to create a gate signal.
A flaw detection signal is created by ANDing with the falling signal. In other words, if a large object is placed in a transparent cylindrical object, the light will be reflected only at the edge of the hole, and this signal will be captured. Inspection performance of transmitted light sensors can also be improved using a similar approach.

[Brief explanation of drawings]

Figure 1 (and) is a perspective view showing a conventional flaw inspection device operating normally, Figure 1 (b) is an output waveform diagram of the photoelectric sensor in Figure 1 (C), and Figure 1 (C) is the same output waveform. Differential waveform diagram of the waveform,
Figure 2 (Jl) is a perspective view showing the conventional flaw inspection device when the rotating roller has stopped, and Figure 2 (b) is Figure 2 (1) K.
2(C) is a differential waveform diagram of the output waveform, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. 4 is a flaw detection circuit 7 in FIG. 3. 5 is a timing chart of each component in FIG. 4, FIG. 6 is a circuit diagram showing an example of the configuration of the rotation detection circuit 8 in Figure 3, and FIG. 2 is a timing chart of various signals in FIG. Code explanation 1... Photoelectric sensor, 2, 3... Lighting device, 4...
Cylindrical object, 5... Rotating roller, 6... Signal amplification amplifier, 7... Flaw detection circuit, 8... Rotation detection circuit, 9
... General meeting judgment circuit, 10 ... Defective product discharge section, 11,
17°°“Differentiator, 12, 13.18...Ratio @5.1
4.19... timer, 15,20... counter,
1.6, 21... Digital comparator representative Patent attorney Akio Namiki Patent attorney Kiyoshi Nezaki Figure 1 ((1) (b) ρ' (C) Figure 2 (G) (b) (C)

Claims (1)

[Claims] 1) Irradiating light onto a cylindrical object that is being sent while rotating Helically scans the wrinkled object** from K, converts the reflected light into an electrical signal using a photoelectric sensor, and outputs it, and processes the output liquid form. The flaw inspection device determines the presence or absence of flaws on both surfaces of the cylindrical object by: a differentiation circuit that differentiates the senna output; and a first detection circuit that detects the presence or absence of a flaw from the continuously generated tie-on of the second output, and from the periodicity of the pulse train in the third output obtained by slicing the differential output by a third threshold value. and a second detection circuit for detecting the presence or absence of rotation of the cylindrical object, and only when the first detection circuit does not detect a flaw and the second detection circuit detects rotation, the cylindrical object is detected. A flaw inspection device characterized in that it determines that it is Tohin.