JP2538994B2 - Side inspection device for circular flat articles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a side surface inspection apparatus for an article having a flat shape or a shape close to a flat shape and having a circular outer periphery, such as a tablet. The present invention relates to a side surface inspection apparatus which has a large throughput in a unit time.

(Prior Art) Conventionally, for surface inspection of an article whose flatness is close to a flatness and whose outer circumference is circular, such as a tablet, for example, the inspection article is placed in a recess formed in two rotary drums vertically or horizontally adjacent to each other. The mainstream method is to inspect the front and back by the image pickup device, and the side inspection is not often done.

As a first method of the side surface inspection apparatus, for example, in “Appearance quality inspection method” of Japanese Patent Application Laid-Open No. 59-87081 and “Optical sensor apparatus” of Japanese Patent Application Laid-Open No. 59-87082, which are filed by the applicant. The disclosed method of imaging the subject on the conveyor belt by the left and right television cameras, and the second method is the transportation disclosed in "Appearance inspection apparatus" of Japanese Patent Application Laid-Open No. 63-66445, which is also filed by the applicant. There is a method of capturing images of the left and right side surfaces of a subject with a single television camera by mirrors arranged on the left and right sides of the belt. The third method is, for example, 45 degrees with respect to the traveling direction of the conveyor belt.
Image the 90-degree range of the subject facing each other by arranging the television camera in the direction of 135 degrees, and arrange the mirror on the opposite side of the television camera centering on the conveyor belt and on the opposite side of the imaging range. There is also a method of imaging the range of 90 degrees. A fourth method is "METHOD AND APPARATUS FOR MEASURING THE SURFACE C in US Patent 4330062.
According to the method disclosed in "OLOR OF AN ARTICLE", four television cameras are arranged in four directions on one plane with one point as the center, and the subject is dropped in the passage in the center and the side surface is imaged. There is something to do.

As a fifth method of rotating the subject for imaging,
There is "Paper Cup Conveying Device" in Japanese Patent Laid-Open No. 58-20280 related to the applicant's application, and a plurality of paper cup rotating devices are provided around a circular rotary table, and a one-dimensional camera is used from diagonally above.
The inside of the paper cup is imaged. Sixth, US
A Patent No. 4493420, `` METHOD AND APPARATUS FOR
DETECTING BOUNDED REGIONS OF IMAGES, AND METHOD AN
D APPARATUS FOR SORTING ARTICLES AND DETECTING FLA
WS "and" ROLL SORTING APPA "in the 4308959 specification.
In the method disclosed in “RATUS”, a plurality of friction rollers are rotated in a loop, and the subject is sandwiched between the friction rollers to be conveyed, and the friction rollers are set in the imaging unit provided in a part of the loop. There is one in which a subject is rotated by rotating it and an image is taken from a top by a television camera.

As a method of rotating the imaging device, there is an “input device in an automatic surface inspection device” of Japanese Patent Application Laid-Open No. 60-56245 filed by the applicant, which projects a light flux of a fixed light source onto a subject by a rotating mirror. Then, the reflected light is reflected by a rotating mirror and is input to the rotating photoelectric conversion device.

(Problems to be Solved by the Invention) As a side surface inspection apparatus, it is necessary that an entire side surface can be inspected, shading and halation are not generated over the entire inspection surface, and both sides of high image quality can be obtained with open image. is there. Furthermore, increasing the amount of treatment per unit time (hereinafter referred to as "a large amount of treatment capacity"), for example, in the tablet inspection described in the embodiment of the present invention, 120,000 treatments per hour (about 33.4 treatments per second) are required. Therefore, the required number of processing units with the same mechanism can be operated in parallel according to the number of processing in a unit time (hereinafter referred to as "multi-row structure"), and the processing units themselves can perform high-speed processing. It must be possible (hereinafter referred to as "high-speed processing capability").

Considering the prior art from these viewpoints, the first method is not suitable for a multi-row structure in addition to the fact that the entire area cannot be imaged because the imaging range covers 180 degrees on the side surface of the subject and the shading around the screen is large. There is a problem. The second method has the advantage that only one camera is required, but the same drawbacks as the first method cannot be avoided. The third method improves the image quality because the imaging range is narrowed to 90 degrees, but it requires two cameras and is not suitable for a multi-row inspection device. The fourth method is a unique method that can obtain good images over the entire side surface, but it requires four cameras and complicates the apparatus, and is not suitable for a multi-row inspection apparatus. The fifth method of placing an image of a subject on a rotary table and performing imaging allows perfect side inspection, but is not suitable for the multi-row type and lacks the capability of high-speed processing.

The sixth method has a large processing capacity and is also an excellent method for transporting an object. The rotation speed and the rotation method of the friction roller are not specified in US Pat. No. 4,393,420, but in the specification of US Pat. No. 4,308,959, the friction roller is brought into contact with an upper portion of a fixed friction member within an imaging range. Is disclosed. Therefore, the peripheral speed of the object is almost the same as the traveling speed of the friction roller loop, and when the friction roller loop travels 2πr when the radius of the object is r, the object rotates once. This is sufficient when the image pickup device is a television camera capable of performing two-dimensional image pickup, but in order to increase the resolution, for example, a one-dimensional image pickup device having a multi-element CCD line sensor can image all sides of the subject. It causes the problem of disappearing.

Furthermore, in order to provide high-speed processing capability, it is desirable to convert a flat subject having a flat posture into a vertical posture before inspecting it. The attitude conversion device used for this purpose is required to ensure that the attitude conversion is performed without causing non-conversion, and that the occurrence of overlap can be prevented in advance. It is not disclosed in.

(Means for Solving the Problem) The present invention provides a posture conversion unit for converting a subject of a circular flat article from a flat posture to a vertical posture, and a subject whose posture is vertically converted by an imaging device. In a side surface inspection device for a circular flat article having a side surface inspection unit that inspects the side surface by rotating, and a selection unit that separates good products from defective products according to the inspection result, the posture conversion unit has a flat posture. A pair of guides having a curved surface that guides the input subject to a vertical posture is provided with a passage that is slightly wider than the width of the subject and is arranged diagonally downward. A pair of guides defining a passage slightly wider than the width of the specimen and a plurality of friction rollers are arranged in a loop, and the specimen is sandwiched between adjacent rollers and driven at a predetermined speed. A friction roller loop, Means for rotating the friction roller at a position including the imaging range on the friction roller loop at a predetermined speed, and one one-dimensional imaging device for imaging an object on the friction roller in the imaging range And is provided.

The posture changing unit consists of a guide that is slightly wider than the width of the subject, a posture changing unit for the subject that is input in a flat form near the input end, and a vertical posture near the posture changing unit and the input end. It is preferable that it is configured by means for giving a swing of the object, means for canceling the overlap of the objects being overlapped and conveyed, and buffer means for suppressing the objects that have been splashed off.

In addition, the ratio of the running speed of the friction belt that gives rotation to the friction roller and the running speed of the friction roller loop in the side surface inspection unit is set to a predetermined value depending on the running direction of the friction belt, and both sides of the center of the adjacent friction rollers are sequentially arranged. It is preferable to capture an image of the subject within the predetermined range.

(Operation) With the above-described configuration, the subject input into the posture changing unit in a flat posture is reliably converted into a vertical posture while falling due to gravity, and is aligned in the passage.

The subject conveyed while being sandwiched between the friction rollers in the side inspection unit is given rotation at a higher linear velocity than the friction roller loop in the imaging unit, and the subject is centered on the imaging line, for example, within ± 45 degrees. It is possible to complete the inspection on the entire circumference of the side surface with high resolution and high speed.

(Embodiment) FIG. 1 is a drawing showing a configuration of an embodiment of a side surface inspection apparatus according to the present invention, in which (A) is a side view and (B) is a top view. It is an inspection. Reference numeral 1 represents the entire apparatus for inspecting the front and back of a flat surface of a subject, and the one using the two rotating drums described above is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-111822, "Transposition of Solid Formulation." The details are disclosed in "Device", "damaged tablet sorting device" in Japanese Utility Model Laid-Open No. 60-119986, "defective tablet sorting device" in Japanese Utility Model Laid-Open No. 63-119431, etc., but they are not the gist of the present invention. Therefore, the description is omitted. Reference numeral 2 is a rotary drum of the second stage of the front and back inspection apparatus 1, 3 is a recess (hole) for accommodating the subject, 4 is the subject, and 5 is a guide for preventing the subject from falling. The inspection object 4 that has been inspected on the front and back sides and has been discharged after being discharged is conveyed to the input end of the posture changing portion 10 of the side surface inspection apparatus 3 of the present invention, so that the guide 5 loses its support. It falls from the inside to the posture conversion unit 10. At this time, compressed air may be jetted from the bottom of the recess 3 to forcefully discharge the subject.

The posture changing unit 6 changes the subject 4 from a flat posture to a vertical posture. The guides 7 are connected at their both ends with metal fittings 8 to form a required number of passages 9 for the subject, and the lower surface thereof. The belt 10 driven by the pulleys 11 and 12 and the tension roller 13 is arranged in the vehicle, and the entire body is slightly downward when viewed in the traveling direction of the subject, and the subject can roll and move on the belt by its own weight. Is done. The passage 9 is slightly wider than the thickness of the subject. The belt 10 is for moving and discarding powder generated from the subject. FIG. 1 (B) shows an example in which eight guides 7 are attached to form seven passages. Guide 7 is shown in Fig. 1 (B)
1 (C) and (D), which are cross-sectional views of X ₁ and X ₂ of FIG.
As shown in FIG. 5, it is preferable that the round bar be shaped such that both side surfaces and the bottom surface are scraped off.

Posture conversion pin at one end of the passage of the subject 4 near the input end
Install 14. The subject 4 discharged in a flat posture from the recess 3 comes into contact with the posture changing pin 14 and is given a rotational force in the horizontal plane and also rotates in the vertical plane. Further, a vibrating device is attached to the lower portion near the input end, and vertically vibrates about a fulcrum 15 near the output end to facilitate posture conversion. Various types of vibration devices can be considered, but in this embodiment, the metal fitting 8 is used.
Attach the block 16 to the lower surface of the input end side of the
The eccentric cam 17 driven by 18 is brought into contact with the eccentric cam 17. Reference numeral 19 is a posture changing plate that stands up along the passage near the posture changing pin 14, and the object 4 that dances due to the vertical force and the rotational force in the horizontal and vertical planes hits the posture changing plate and returns to the passage. do. Most of the subject 4 hits the posture conversion plate 19 on the right side of the passage, but there is also one that hits the left side. Most of the subject 4 is converted into a vertical posture by the posture changing pin 14 and the posture changing plate 19, but there is a case where a flat subject is still carried on the vertical subject, so that the subject 4 is transported. , The thin and elastic plastic filaments are planted in several places around a small diameter drum, and the impeller 20 is rotated to bounce off the subject placed on it and release the overlap. . The rotation direction of the impeller 20 may bounce off the subject 4 toward the downstream side or may bounce off toward the upstream side. When splashing toward the downstream side, it is preferable to attach a relaxation film 21 made of a flexible plastic sheet in order to absorb the impact when falling. It is also preferable to increase the height of the downstream side portion 22 of the guide 7 in order to ensure the posture change in this portion. When the subject 4 is splashed toward the upstream side, it falls into the original passage and is converted into a vertical posture. At this time, the buffer film 21 is not necessary, and the downstream side portion of the guide
No need to raise 22. The posture changing device may be modified in various ways other than the above embodiment.
For example, an object input in a flat posture can be smoothly and gradually converted into a vertical posture by using a guide having a curved surface and applying no shocking force, by a small acceleration of the same magnitude. . At this time, since the subject does not dance, the posture changing pin, the posture changing plate, the vibrating device, the impeller, etc. are unnecessary. However, such a guide is difficult to design and manufacture, and in the case of small-volume production, the cost is high, which is not suitable for practical use. There is also the idea of making this guide into a duct. In this case, the structure is the simplest, but in the case where a part of the subject is lacking or in the case where powder is likely to come out, the subject may be caught and clogged on the way. A short duct is less likely to cause this, and the structure can be simplified.

In the side surface inspection unit 30, the subject 4 is conveyed while keeping the vertical posture correctly, the subject is rotated in the image capturing unit, the entire side face is imaged by the one-dimensional imaging device, and the image is analyzed by the computer. Decide good or bad.

As a conveyance method, first, a plurality of friction rollers 31 are connected by, for example, a chain (not shown), and an appropriate interval (described later).
Then, the loop 32 is driven by the sprocket wheel 33 in the direction of the arrow at the traveling speed V ₁ , and the subject 4 is sandwiched between the friction rollers 31 and conveyed. As the rotation device of the subject 4 in the imaging unit, a friction roller 31 is used.
A friction belt 40 is provided in contact with the lower part of the, and this is driven by a pulley 41 to rotate the friction roller 31 by friction to rotate the object 4 to be clamped clockwise in FIG. 1 (A). is there. The friction roller 31 is preferably made of a material such as silicon rubber having a large friction coefficient and withstanding abrasion. The friction belt 40 may be made of a rubbery material, and may be provided at one location or two locations on the right and left sides in the central portion when viewed in the width direction of the friction roller row. It is preferable that the friction belt 40 be rotated in the same direction as the friction roller loop 33 (clockwise in FIG. 1A, hereinafter referred to as “forward direction”), and the traveling speed of the friction belt is the friction roller loop. It will be faster than the running speed as described below. The friction belt 40 may rotate in the opposite direction. However, at this time, the traveling speed of the friction belt needs to be higher than that in the case of the forward direction. In this way, the subject 4 can be rotated by pinching and transporting the subject 4 between the friction rollers 31 forming the friction roller loop 32 and rotating the friction roller in the imaging unit. In the conventional specimen rotation apparatus, the two-dimensional image pickup apparatus is used as described above, and the traveling speeds of the friction roller loop and the friction roller are equal to each other. Therefore, it should be applied to the inspection apparatus using the one-dimensional image pickup apparatus. I can't.

A required number of guides 34 similar to the posture changing unit are attached to the passage of the subject 4 to form a passage slightly wider than the width of the subject so that the subject can be conveyed in a correct vertical posture. There is. This guide is a unit of the required number
35 is configured to be replaced with a dedicated unit when inspecting subjects with different widths.

Next, details of the image pickup unit will be described. The area delimited by (X ₃ −x ₃ ) and (X ₄ −X ₄ ) is the image pickup section 36, and a one-dimensional image pickup apparatus 37 using, for example, a CCD line sensor is arranged in the upper center of the image pickup section 36. One-dimensional line sensor is, for example, 2048
Since it is possible to use a multi-element device such as an element, an extremely high-resolution image can be obtained. Further, since the sub-scan is performed by transporting the subject, there is an advantage that the configuration is simpler than that of the television. As such an image pickup device, a known device can be used.

Illumination of the subject is performed by an illumination device 38 mounted diagonally above and behind the subject. Illuminating obliquely from above does not allow direct reflected light to enter the image pickup device, which is advantageous in avoiding halation.

FIG. 2 is a drawing for explaining the mutual relationship among the friction roller 31, the friction roller loop 32, and the subject 4. First, referring to (A), it is necessary that the contact angle α between the friction roller 31 and the subject 4 is an appropriate size. If the contact angle α is too large, the subject tends to be crushed by the friction roller and is too small. Then, the subject floats and the rotational force is not transmitted. Since the method of determining the appropriate corner is known, it will be omitted. The ratios of the linear velocities reduced due to the slip between the friction belt 40 and the friction roller 31, and between the friction roller 31 and the subject 4, that is, the power transmission coefficients between them are k ₁ and k ₂ , respectively.
Then, when the traveling speed of the friction belt 4 is V ₂ , the peripheral speed of the subject is k ₁ k ₂ V ₂ . This k ₁ k ₂ V ₂ is set to be equal to or higher than a predetermined value described below in comparison with the speed V ₁ of the friction roller loop 32, and the entire circumference of the subject is imaged while the predetermined range of the subject passes through the image pickup line. And pass through the entire circumference of the subject to be inspected. This predetermined range is the angle formed by the line connecting the imaging point on the surface of the subject and the center of the subject and the imaging direction (when the subject is circular, the angle formed by the imaging line and the perpendicular to the imaging surface). The range in which θ does not become too large, for example,
Take 45 °. The reason for limiting the value of θ is to suppress the distortion and shading of the screen to such an extent that the inspection is not hindered, and to keep the fluctuation of the position of the imaging point 39 within the range of the depth of focus of the imaging device. Referring to FIGS. 2 (B) to (E) and considering the case where the traveling direction of the friction belt 40 is the forward direction, the center of the subject is the imaging point at the time of starting the imaging.
It is located at O ₁ on the left side of 39 (imaging point a), the subject rotates (π−θ) after t seconds, passes through O ₂ on the imaging line (imaging point is a ′ on the opposite side of a), and After t seconds, the object is (π
-Θ) If it is moved to the right side O _{3 of the} imaging point when it is rotated (imaging point a), when the center is moved after t seconds, the length l is
If the radius of the object is r, then l = V ₁ t = r sin θ (1). The rotation angle (π−θ) between t becomes π−θ = k ₁ k ₂ V ₂ / r (2), and if V ₂ / V ₁ is calculated from (1) and (2), then V ₂ / V ₁ = (Π−θ) / k ₁ k ₂ sin θ (3)

From the above formula, it is possible to determine the specifications required for the operation of this device. First, the maximum imaging angle θ of the subject 4 is determined, V ₂ is determined from the given k ₁ , k ₂ and V ₁ by the equation (3), the rotational speed of the friction belt 40 is determined, and calculation is performed by the equation (1). The computer may control so as to capture an image of the range of ± 1. It is easy to make the distance between the friction rollers 31 constant by a method such as driving the friction roller loop 32 using a chain, and since the diameter of the subject 4 is constant for the same type of subject, it is sandwiched by the friction rollers. The center line of the inspected object passes through the centers of the adjacent friction rollers that are nipped. For this reason, the center of the optical sensor 42 provided in the portion after the defective product is discharged on the friction roller loop 32 and
43 allows the edge of the friction roller to be detected and then easily calculated by the computer.

If θ = 45 ° now, the equation (3) becomes Becomes If there is no slippage, k ₁ = k ₂ = 1.
The above formula is V ₂ / V ₁ ≈ 3.34 (5). At this time, the friction belt 40 is a friction roller loop.
The computer 60 may be controlled to rotate at a traveling speed of 3.34 times the traveling speed of 32 and image the range of ± 1 calculated by the formula (1) from the center of the adjacent friction roller 31. Actually, since there is slippage, it is necessary to increase the speed of the friction roller by the amount of slippage in equation (3).

When the traveling direction of the friction belt 40 is set to the opposite direction: When the center of the subject moves from O ₁ to O ₂ , the rotation angle of the subject for t seconds becomes π + θ, and the equation (3) is as follows. become.

V ₂ / V ₁ = (π + θ) / k ₁ k ₂ sin θ (6) When θ is 45 °, Eq. (6) becomes V ₂ / V ₁ ≈5.63 (7). That is, since v ₂ is about 1.7 times that in the forward direction, it is preferable that the rotation direction be the forward direction.

The object 4 that has passed through the side surface inspection unit is a friction roller loop.
A semi-circular guide 44 provided at the end of 32 conveys it to the lower part of the loop while preventing it from falling, and here, a sorting unit 50 sorts good products and defective products. In the sorting section, the good product is dropped from the good product discharge port 54 by its own weight,
Discharge to 55. When defective products are delivered, the solenoid valve
53 drives the air cylinder 52, the shutter 51 closes the non-defective product discharge port 54, and conveys it further to the defective product discharge port.
It is dropped from 56 and discharged to the defective product discharge path 57.

The computer 60 receives the outputs of the above-mentioned θ · r · V ₁ · k ₁ · k ₂ and the optical sensor 43 as input and uses the sprocket wheel 3
3, friction belt wheel 41, one-dimensional imaging device 37, solenoid valve 5
3. Configure to control the optical sensor device.

(Effects of the Invention) With the configuration described above, it is possible to reliably and efficiently convert a large number of subjects carried in a horizontal posture by the multi-lane lane into a vertical posture in the posture conversion unit. It became possible to perform high-speed side inspection at the stage. In the side surface inspection section, while conveying at high speed, all the side surfaces at a small angle of distortion and shading,
Imaging with a high-resolution one-dimensional imaging device has made it possible to perform inspection with high accuracy, high quality, and high efficiency. Also, both parts have high-speed processing capability,
Since it is suitable for multi-row type, it can effectively realize a large processing capacity, and its total effect is truly great.

The present invention achieves its object by combining the posture conversion unit and the side surface inspection unit, but it can be used for other purposes by utilizing the functions of both units. For example, the posture conversion unit can be used not only for surface inspection but also for posture conversion for processing an article or the like. By changing the guide, the side inspection unit can be used not only for flat circular articles, but also for articles having a circular cross section, such as cylindrical, spheroidal, and spherical articles.

[Brief description of drawings]

1 (A) to (D) are side views, a top view and a cross-sectional view showing a schematic configuration of the present invention, and FIGS. 2 (A) to (E) are
6 is a diagram for explaining a relationship among running, rotation, and imaging by a friction belt, a friction roller, a friction roller loop, and a subject. 4 ... Subject, 6 ... Attitude conversion unit 7 ... Guide, 10 ... Conveyor belt 11,12 ... Pulley, 14 ... Attitude conversion pin 15 ... fulcrum, 17 ... Eccentric cam 18 ... Motor, 20 ...... Impeller 30 ...... Side image pickup unit 31 ...... Friction roller 32 ...... Friction roller loop 36 ...... Image pickup unit 37 ...... One-dimensional image pickup device 38 ...... Illumination device 39 ...... Image pickup point 40 … Friction belt 50 …… Sorting section, 51 …… Shutter 52 …… Air cylinder, 53 …… Solenoid valve 54 …… Good product discharge port, 55 …… Good product discharge path 56 …… Defective product discharge port, 57 …… Defective product Discharge path 60 ... Computer

Claims (6)

(57) [Claims] 1. A posture conversion unit for converting a subject of a circular flat article from a flat posture to a vertical posture, and a side surface thereof is inspected by rotating the subject whose posture has been changed vertically by an imaging device. In the side surface inspection device for a circular flat article having a side surface inspection unit that performs the inspection, and a sorting unit that separates a good product from a defective product according to the inspection result, the posture conversion unit vertically detects the object that is input in a flat posture. With a pair of guides having a curved surface that guides the posture, there is a space slightly wider than the width of the subject, and a passage arranged obliquely downward is provided, and the side surface inspection unit has a space slightly wider than the width of the subject. A pair of guides that define the passage of the friction roller, a plurality of friction rollers arranged in a loop, and a friction roller loop that is driven at a predetermined speed by sandwiching an object between adjacent rollers, and the friction roller. Taken on the loop A means for applying a predetermined speed of rotation to the friction roller in a position including the range, and a one-dimensional image pickup device for picking up an image of a subject on the friction roller in the image pickup range are provided. Side inspection device for circular flat articles. 2. A posture changing pin is provided near the input end of the posture changing section at a position where one end of the subject input in a flat shape is applied, and a posture changing plate is provided in the vicinity thereof in parallel with the passage. 1. Side inspection device for circular flat articles. 3. A side surface inspection apparatus for a circular flat article according to claim 1, further comprising means for vertically swinging at least a member near the input end of the posture changing section. 4. The side surface inspection apparatus for a circular flat article according to claim 1, wherein the posture changing section is provided with an overlap canceling means for the objects being overlapped and conveyed. 5. The side surface inspection apparatus for a circular flat article according to claim 4, wherein the overlap canceling means is provided with an impeller for canceling the overlap by splashing off the objects conveyed in the overlapped manner. 6. A friction belt is contacted with a lower portion of the friction roller to drive the friction roller as a means for rotating the friction roller, and the traveling speeds of the friction roller loop and the friction belt are set to V ₁ and V ₂ , respectively. The power transmission coefficients between the friction roller and between the friction roller and the subject are k ₁ and k ₂ , respectively, and the angle between the straight line connecting the imaging point and the center of the subject and the imaging direction is θ, and When the radius of the specimen is r and the traveling direction at the contact point is the same as the friction roller loop and the traveling direction, the traveling speed is V ₂ / V
₁ = (π = θ) / k ₁ k ₂ sin θ A value obtained from the formula, and when the opposite direction is applied, V ₂ / V ₁ = (π + θ) / k ₁ k ₂ sin
2. The side surface inspection apparatus for a circular flat article according to claim 1, wherein a numerical value obtained from the equation of θ is used, and the subject in the range indicated by l = r sin θ is imaged on both sides from the center of successive friction rollers.