JPH0423741B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a medical capsule inspection device, and more particularly to a capsule inspection device for detecting defective capsules called twin caps before drug filling. This relates to inspection equipment.

[Prior art and its problems]

FIG. 1a is an external view of the capsule to show that the cap 1 and body 2 are in a temporary bonded state in an empty capsule before being filled with a drug, and FIG. 1b is an external view of the capsule after being filled. This is an external view showing that the two are in a fully connected state. Note that 3 indicates a notch for locking each other with a snap when the cap and body are combined.

In Fig. 1b, the tip of the body 2 has penetrated deep into the cap 1, and the body and cap are permanently connected, whereas in Fig. 1a,
It can be seen that the tip of the body 2 does not go all the way into the cap 1 and is in a temporarily connected state.

The body and cap, which are in this temporary bonded state, have a weak bonding force and are therefore easy to separate from each other. Therefore, when such an empty capsule is subjected to vibrations by an inspection device, the cap comes off from the body and is later joined to the body of another normal capsule, resulting in a defective capsule (hereinafter referred to as
Also called twin cap capsule. ) may be made. Incidentally, FIG. 2 is an external view showing such a twin cap capsule.

A device for automatically detecting such twin cap capsules without visual inspection has already been filed by the same applicant as the present application. (Special application 1987-
No. 158178 (Japanese Unexamined Patent Publication No. 59-48645)). In that invention, as seen in FIG. 2, attention is paid to the fact that twin cap capsules always have two notches, and by detecting this, it is possible to identify twin caps. However, although the method of the above application is effective for most capsules, it was found to be insufficient for a certain portion of capsules. In other words, if the material of the capsule body is opaque and the material of the cap is between transparent and opaque, the signal from the notch will be weak and the difference from the noise signal in the body will be small, and the signal from the notch will be weak. The problem is that the method of the above-mentioned application, which is based on the premise that the signal is sufficiently larger than the signal in the body part without the notch part, makes determination difficult.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a new inspection device that can accurately discriminate between twin caps and non-defective products even when there is a small difference between the cap notch signal and the bottom noise signal as described above.

[Key points of the invention]

We compared the signals from the cap notch and the noise signals from the body in detail, and focused on the following differences.

Two notches are provided on the cap (if the state shown in Figure 2 is the front side, there are also two notches on the back side). For this reason, two signals are generated from one notch while the capsule rotates once during the transportation process, so the integral output obtained by integrating these signals is normally transmitted from the body only once or less. It is sufficiently larger than the integral value of the signal (noise) that does not occur.

That is, in the present invention, in order to detect the above-mentioned difference, the above-mentioned differential signal is rectified and then integrated in two regions corresponding to the notch portion of the twin cap, and the results are compared with the standard value. If the value exceeds the standard value, it is judged as the cap part, and if it is lower than the standard value, it is judged as the body part, so if it is a twin cap (defective product), there are two cap parts, and otherwise, there is one cap part. Since this is detected, twin caps (defective products) are determined based on this detection.

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

Generally, an appearance inspection device using an optical sensor for a cylindrical object such as a capsule has already been proposed by the present inventors (for example, in Japanese Patent Application No. 57-040183), and as for the optical sensor, Since it is also used in the present invention, its outline will first be explained below.

FIG. 3 is a sectional view showing an outline of such an optical sensor. In the figure, 5 is a capsule that advances while rotating, 6 is a light source 7, a condenser lens 8, a half mirror 9, a lens 10, and an aperture 1.
1, a photodiode 12, and the like.

In FIG. 3, light emitted from a light source 7 is condensed by a condenser lens 8, then its optical path is bent by 45° by a half mirror 9, and is irradiated onto a capsule 5 via a lens 10. The light reflected on the capsule surface enters a photodiode 12 via a lens 10, a half mirror 9, and an aperture 11.
The amount of incident light is photoelectrically converted by the photodiode 12, and its output is guided to a determination circuit to be described later.

FIG. 4 is an explanatory diagram showing that in a depression such as a notch, the amount of reflected light decreases, and therefore the sensor output also decreases.

In the figure, in the flat region A, the light 15 irradiated from the sensor is specularly reflected 360° in the optical axis direction of the sensor, so that the amount of light reaching the photodiode is large. In such inclined region B, since the reflected light 16 is reflected in a direction different from the optical axis of the sensor, the amount of light reaching the photodiode is small.

Next, the waveform of the sensor output obtained by optically scanning the rotating capsule with the sensor will be described with reference to FIG.

In FIG. 5, since the capsule advances while rotating, the optical scanning direction by the sensor is Y ₁ ,
The direction will be as shown by Y ₂ . Notch 3 will be explained assuming that two scans, _Y1 and _Y2, have been performed. Note that the speed of rotation of the capsule is selected to be considerably larger than its transport speed.

The region corresponds to the tip of the cap 1, and since the tip is more rounded, the amount of reflected light reaching the sensor is smaller. In the area, the cap 1 and the body 2 overlap, so the amount of reflected light is greater than in the case of the cap alone or the body alone, as in the area or. In terms of area,
The amount of reflected light is reduced due to the dents created by the notches 3. A region is similar to a region, and a region is a region where almost no amount of reflected light is obtained due to diffusion.

Next, the determination circuit of the present invention will be explained.

FIG. 6 is a block diagram showing the determination circuit of the present invention. In the figure, 20 is an amplifier, 21 is a differential circuit, 22 is a rectifier circuit, 23 is an integrator with a reset switch (SW), 24 is a comparator, 2
5 and 26 are flip-flops, AN1~
3 is an and gate. Integrator 23 switch
SW is normally closed and the mask signal F-
It is opened and performs an integral operation only when MASK or R-MASK occurs. Note that the mask signal F-
MASK and R-MASK are emitted in response to two notches, respectively, and are emitted a predetermined time after the tip of the capsule is detected, that is, at a position where the notch is predicted to exist. In this type of capsule inspection device, the capsule to be inspected is placed in a capsule accommodation hole provided in a conveyance means such as a conveyance belt or a conveyance drum (the length of this accommodation hole is larger than the length of the capsule depending on the size of the capsule). Since the structure is such that the capsule is transported to the inspection position while housed in a slightly larger capsule, once the type of cap and body of the capsule is decided, it is possible to avoid notches in the case of a twin-cap capsule. The area is also limited to two ranges. Therefore, it is preferable to generate mask signals F-MASK and R-MASK at two positions where a notch is expected to exist, as in this embodiment, so as not to extract unnecessary noise signals. .

Figures 7A and 7B are waveform diagrams of various signals in Figure 6. In particular, Figure 7A shows the case when normal capsule CA is scanned (normal operation), and Figure 7B shows the case when twin cap capsule CB is scanned (abnormal operation). motion)
FIG. 3 is a waveform diagram of each part signal obtained respectively in FIG.

Next, the operation of the present invention will be explained with reference to FIGS. 6, 7A, and 7B. The input signal a, which is the sensor output, is amplified to an appropriate voltage level by the amplifier 20, and then differentiated by the differentiator circuit 21, resulting in a differential output b. Differential signal b is rectifier circuit 2
2 and then enters the integrating circuit 23 (signal c
reference). The reset switch SW of the integrating circuit 23 is
F-MASKd, R- indicating the position of the notch part
It is opened by MASKe and performs an integrating operation, so that the rectified signal c is integrated during the period when the signal d or e is on. The integrated waveform f is compared with the reference voltage V _S by the comparator 24, and furthermore, this binarized signal g is input to F-MASK, R- by the AND gates AN1 and AN2.
Synchronized with MASK signal. Flip-flops 25 and 26 are set by signals via AND gates AN1 and AN2, and their outputs h and i are applied to AND gate AN3. Therefore, when a normal capsule is inspected, the flip-flop 25 is set, but the flip-flop 26 is not set, so the output signal j of the AND gate AN3 does not become on level, whereas when a twin cap is inspected, the flip-flop 26 is not set. As can be seen from the waveforms h, i, and j shown in FIG. 7B, flip-flops 25 and 26 are both set and the output signal j is set to the on level, which indicates that it is a twin cap capsule.

〔Effect of the invention〕

According to the present invention, the following effects can be expected.

(a) Since the notch that is always formed on the cap is detected, it is possible to reliably identify a twin cap capsule that is a defective capsule. For example, if the body is short or the cap is long, there is also a twin cap capsule in which the gap ΔC between the twin caps in FIG. 2 becomes zero. in this case,
Although it is difficult to reliably detect twin caps with the method of determining twin caps by detecting the inter-cap gap ΔC, the present invention can reliably detect twin caps even in such a case.

(b) By using a coaxial reflective sensor as explained with reference to FIG.
Since the waveform is as shown in Figure A or 7B, the present invention can be applied to all capsules.

[Brief explanation of drawings]

Figure 1a is an external view of an empty capsule before drug filling;
Figure 1b is also an external view of the capsule after filling;
The figure is an external view of the twin cap capsule, Figure 3 is a configuration diagram showing an overview of the optical sensor, Figure 4 is an explanatory diagram to explain the mode of reflection in a recess such as a notch, and Figure 5 is around a predetermined axis. FIG. 6 is a block diagram showing an embodiment of the present invention, and FIG. 7A shows normal operation. FIG. 7B is a waveform diagram of each part for explaining abnormal operation. Code explanation, 1...Cap, 2...Body, 3
...Notsuchi, 5...Capsule, 6...Sensor, 7
... Light source, 8 ... Condenser lens, 9 ... Half mirror, 10 ... Lens, 11 ... Aperture, 12 ... Photodiode, 20 ... Amplifier, 21 ... Differentiation circuit, 22 ... Rectifier circuit, 23
...Integrator circuit with reset switch, 24...Comparator, 25, 26...Flip-flop.

Claims (1)

[Scope of Claims] 1. A capsule inspection device that projects light onto a capsule being transported in the direction of the longitudinal axis while rotating around the longitudinal axis, and inspects whether the capsule is a twin-cap capsule based on the amount of reflected light. A differentiating circuit for an electric signal obtained by photoelectrically converting reflected light, a rectifying circuit for rectifying the differentiated output from the differentiating circuit, and first and second circuits corresponding to two specific locations on the surface of the capsule. a mask signal generating means; an integrating circuit that integrates the rectified output from the rectifying circuit only during a period during which mask signals are output from the first and second mask signal generating means, respectively; and the first and second masks. 1. A capsule inspection device comprising: determination means for determining that the capsule is a twin-cap capsule when all of the integral values of the integration circuit corresponding to the signals exceed a certain constant value.