JPH07198616A - Test sample testing device - Google Patents

Abstract

PURPOSE:To increase the test accuracy for the surface of a test sample such as a tablet or the like by transporting a test sample seated extending over a pair of transport belts clamping a suction hole array in a stable attitude while pressing the same to the transport belts by suction negative pressure, and image picking up the same by an image pick-up part so as to be tested. CONSTITUTION:A guide plate 22 is provided with plural arrays of suction holes penetrating at equal spaces in the transport direction, and guide rails 23 engaged with recessed grooves of a pair of transport belts l to guide the belts 1 in the transport direction are fixed on both sides of the respective suction hole 22a arrays on the upper surface of the guide plate 22. Tablets T are placed on the transport belts 1 to be transported, both sides of which guide rails 23 by suction negative pressure from the suction holes 22a arranged on the guide plate 22 and driven. The surface of the tablet is image-picked up to be tested. Thus, two-dimensional slippage of the belts can be prevented, a broken piece of the tablet T can be prevented from being caught in the suction hole 22a, and even if powder of the tablet T adheres to the suction hole 22a, it is not image-picked up, so that the test accuracy for the surface of the tablet can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a small object such as a tablet while inspecting it for damage.

[0002]

2. Description of the Related Art As a conventional example of this kind, various types have been proposed. Among them, a slit serving as an intake port is formed, and guides formed at both ends of the slit are formed. A pair of ropes that are individually guided by rails are provided, the subject is placed on the ropes, negative pressure is applied through the slits to convey the specimen while adsorbing it, and the specimen is held at a predetermined position. There is disclosed one in which an image of a sample is taken and an inspection is performed (see Japanese Patent Publication No. 5-65405).

[0003]

However, in the above-mentioned conventional example, the following various problems occur. First, it is substantially difficult to form a slit by punching out a sheet of metal or the like. That is, since it will be bridged only on the outside of both ends in the longitudinal direction of the slit,
Even if a sheet metal material with high rigidity is used, it is practically difficult to hold both surfaces sandwiching the slit on the same surface,
The generation of the step could not be avoided.

Therefore, in the end, a slit is formed by abutting the edges of a plate material having high pressure and high rigidity, but in that case, extremely high processing precision and assembly precision are required, and the slit formation is performed. This alone causes a significant increase in manufacturing cost, and also requires maintenance to maintain good slit accuracy even after use.

Further, since the transport cords slip with respect to the drive pulley, the transport time from the imaging position of the subject to the sorting position selected by the inspection result becomes unequal, which may cause a sorting error. There is. Further, the slips of the pair of cords may be different from each other, and in this case, the subject may be rotated around the horizontal direction, and the reliability of the test result may be lost. Alternatively, the cord may rotate or twist in the circumferential direction of the circular cross section. In this case, the subject may fall into the slit and may be erroneously determined to be damaged by the inspection. There is also this.

Further, since there is usually a cord on the outside of the slit in which the guide rail is formed, when a fragment of the subject gets caught between the slits, if the fragment is projected above the cord, The fragments bounce off the fragments, and even if they do not reach that point, the impact causes displacement and vibration, which causes an error in the imaging inspection. Further, although imaging is performed at a predetermined location, if a fragment of the subject is caught between the slits of the imaging location, the fragment may be captured by the imaging and an error may occur in the inspection. In addition to the method of imaging the entire subject in a planar manner for imaging, reciprocal scanning is repeated in a linear direction intersecting the transport direction using a line sensor, and the captured linear images are joined in time series to form a planar image. However, in the former method, an inspection error occurs when debris overlaps the outside of the subject at the timing of imaging, and in the latter case, debris is present on the scanning line. And since it does not move at this position, debris will always be imaged,
The images connected in a plane form tend to cause a streak having a width of the debris on the outside of the subject and cause an inspection error. Further, in the method of imaging in the planar or linear shape, for example, even if it is out of the imaging area, if debris is caught in the vicinity, the caught part becomes an obstacle and the space between the cords is interrupted. When the negative pressure for sucking the subject is weakened and the subject is a round tablet, etc., when the front side is above the catching portion when passing through the catching portion, the rear side is sucked to a relatively strong negative pressure. And tilts backward, and then when the rear part is at the catching part, the front side is strongly sucked and tilts forward, so that it vibrates greatly, and in this case also an inspection error occurs.

The above is the case where the debris exists near the image pickup location, but there is a problem that it occurs with a higher probability. This is a problem that occurs in a subject such as a tablet, where fragments are finely crushed to form powder and adhere to the inside of the slit. The generation of such powder is unavoidable in tablets and the like, and if the amount of powder generated increases as the transportation continues for a certain amount or more, the powder uniformly adheres to the entire inner wall of the slit, that is, the imaging portion is attached without exception. In that case, in both the planar imaging method and the linear imaging method, the powder adhering to the inner wall of the slit is imaged in parallel streak shapes, and there is a possibility that the powder may be particularly regarded as a crack or a flaw. High and an inspection error occurs.

Since the occurrence of the inspection error due to the catching of the fragments and the adhesion of the powder in the vicinity of the image pickup position as described above occurs similarly for all the test objects, once they occur, the inspection becomes substantially impossible. This is a big problem because it is necessary to stop the inspection and remove debris and powder. In addition, the powder of the subject is likely to enter between the cord and the guide rail, in which case not only slippage of the cord may lead to the above-mentioned inspection error, but also the cord or the guide rail surface may be worn. It may be a problem in terms of durability.

Incidentally, it is conceivable that the end edges of the cords are mounted so as to be protruded inward from the slits in which the guide rails are formed. In that case, the gap between the cords is smaller than the gap between the slits. , Debris of the subject dropped from the gap between the cords falls without being caught in the slit, and fragments caught between the pair of cords are transported as they are, so it is possible to remove them by providing a removing means such as a rotating brush on the downstream side. Further, it is possible to prevent the powder from adhering to the slit wall and entering between the cord and the guide rail to some extent. However, it is necessary to push the guide edge to the guide rail with a certain amount of tension or more in order for the rope to move stably, so that it is necessary to push the guide edge toward the inside of the slit. The same part of the cord is always pressed against the edge of the slit with considerable strength by being subjected to suction negative pressure, and is rubbed against the edge of the slit. It is almost impossible to adopt.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a shape and a positional relationship between the suction port and the transfer system,
It is an object of the present invention to provide an object inspection apparatus capable of greatly improving the reliability of an inspection that solves the above problems by devising the imaging position and the like.

[0011]

For this reason, the subject inspection apparatus according to the present invention is attached to a suction box in which a negative pressure is introduced into the internal space by a negative pressure source, and is attached so as to cover the opening surface of the suction box. A guide plate having at least one row of suction holes having a large number of suction holes opened at equal intervals in the direction, and a guide plate provided with convex guide rails on both sides of the row of suction holes, and suction of the guide plate. A timing pulley that is rotatably supported by the suction box and has one end rotatably driven by a drive source, and an annular timing at which both ends engage with the timing pulley. The belt-shaped inner peripheral surface is formed with an annular recessed groove that engages with the guide rail at the center in the width direction, and the portion on the opposite side of the guide rail and the guide plate is the suction button. And a plurality of conveyor belts mounted so as to pass through the inner space of the suction hole. The pair of conveyor belts are formed to have a size outside the outer diameter of a circle whose diameter is the gap between the opposite side edges of the conveyor belt, and which bridges between adjacent suction holes. And a conveyance section that is set to be equal to or smaller than the gap between the side edges facing each other, and a subject that is conveyed while being seated across a pair of conveyance belts outside the predetermined suction hole. A linear image of the subject is picked up by periodically performing reciprocal scanning in a linear direction that passes through the center of the suction hole and does not intersect with the peripheral edge exposed from the gap of the transport belt of the suction hole. An image pickup unit that obtains a surface image of the subject by connecting the linear images in time series , Characterized by comprising a.

[0012]

Describing from the basic operation outline, the subject to be seated across the pair of conveyor belts sandwiching the suction hole array is
The negative pressure of suction introduced from the suction box through the suction hole pushes it against the conveyor belt, conveys it in a stable posture, and an image is picked up by an image pickup unit at a predetermined position for inspection.

Next, the individual actions characteristic of the present invention will be described. First, even if a large number of suction holes are arranged in a row, the guide plate forms a slit by bridging the suction holes with each other. There is no step as in the case of Therefore, even if a thin plate material is used as the material for forming the guide plate, sufficient accuracy can be ensured, and no assembly accuracy is required.

Further, since the timing belt-shaped belt is used as the carrying belt, the occurrence of slip in the carrying direction can be regulated, and the lateral deviation in the direction perpendicular to the carrying direction can be achieved due to the engagement between the groove and the guide rail. Regulated. as a result,
Since it is possible to suppress the vibration of the transport belt and the relative movement between the pair of transport belts, it is possible to prevent the subject from swinging, rotating around the horizon, or twisting due to this. It is possible to prevent the occurrence of inspection error.

Further, the suction hole is larger than a circle having a diameter between the pair of conveyor belts sandwiching the suction hole, and the length of the portion bridging the adjacent suction holes is between the pair of conveyor belts. Since the size is less than the gap, most of the debris of the subject dropped from the gap fell from the suction hole into the internal space of the suction box, and the debris happened to ride on the portion between the suction holes. Even in this case, unlike the case where a fragment is sandwiched between the slits and fixed, there is no fixing force, and therefore, there is no possibility of being hit by the subject and being repelled and affecting the examination.

The debris caught between the transport belts is transferred together with the transport belts and removed by suction in the internal space of the suction box, and can be reliably and easily removed by providing a removing means on the downstream side of the transport path. . Moreover, even if the powder of the fragments of the subject adheres to the periphery of the suction hole,
On the imaging scanning line of the imaging unit, the edge of the suction hole is hidden behind the conveyor belt, so that the powder is not imaged and an inspection error due to the powder imaging can be prevented.

Further, since the transport belt is transported while being supported by the bridging portions between the suction holes, it does not wear at the edges of the suction holes, and further, the powder adhered to the transport path surface of the guide plate is not removed. Since the teeth of the carrying belt are scraped out in the carrying direction, the cleaning effect is high, and the wear of the carrying belt and the guide plate carrying road surface due to the powder can be prevented and the durability is excellent.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is applied to an apparatus for carrying out an inspection while transporting tablets as a subject. 1 to 7 showing the configuration of the present embodiment, the schematic configuration will be described. An annular ring provided in a plurality of rows adjacent to each other for mounting and transporting tablets as a subject supplied from a tablet supply device described later. And a suction box 2 for arranging the one row of the transport belts on the upper part and sucking a subject on the transport belts 1 through a gap between the pair of transport belts 1. And an inspection device for inspecting by imaging the surface of the tablet conveyed by the conveying device.

Each section will be described in detail below. Each of the conveyor belts 1 is composed of a timing belt having an inner peripheral surface with teeth, and a groove 11 is formed at the center in the width direction. On the other hand, on the upper end of the suction box 2, a thick holder 20 is fixed, which is entirely opened except for a portion which bridges the lower portion of the conveying belt 1 at a predetermined interval in the conveying direction. A guide plate 22 is connected to the upper surface of a flange member 21 having a U-shaped cross section, which is fixed on both outer edges of the open portion of the holder 20, with both side edges fixed. The guide plate 22
A plurality of rows of circular suction holes 22a formed at regular intervals in the carrying direction (four rows in the embodiment, but only two rows are shown in FIGS. 1 and 2 for the sake of simplicity). Guide plate 22
Guide rails 23 that engage with the concave grooves 11 of the pair of conveyor belts 1 and guide the conveyor belt 1 in the conveying direction are fixed to both sides of each row of the suction holes 22a on the upper surface.

Both ends of the conveyor belt 1 are hooked on toothed timing pulleys 24 and 25 which are rotatably supported at both ends of the side wall of the suction box 2, and the conveyor belt 1 is
The portions below the timing pulleys 24, 25 are introduced into the suction chamber 26 inside the suction box 2 and are also applied to the idler pulleys 27 in the suction chamber 26 to give a predetermined tension. In this way, the diameter of the suction holes 22 is formed larger than the gap between the facing inner edges of the conveyor belts 1 mounted on both sides of the row of suction holes 22.
The length of the portion bridging the adjacent suction holes 22 is smaller than the gap between the transport belts 1. For example, the gap between the conveyor belts: the diameter of the suction holes: the length between the suction holes ≈
It is about 2: 3: 1.

The end of the one timing pulley 24 is
It is connected to a drive motor 28, and by driving the drive motor 28, the conveyor belt 1 is driven at a constant speed without slipping. Further, the bottom wall of the suction box 2 has a central opening, and the duct 3 connected to the opening.
Air is sucked by a vacuum pump or the like (not shown) through the suction box 2, and the suction hole 22
A negative suction pressure is applied to the tablets on the conveyor belt 1 from a,
The tablet T is conveyed while being pressed against the conveyor belt 1.

On the other hand, there is provided an image pickup device 4 (image pickup portion) for picking up an image and inspecting the surface of the tablet T conveyed to a predetermined position above the conveying belt 1 of the conveying device (conveying portion). The image pickup device 4 has a one-dimensional image pickup element (line sensor) for reciprocally scanning at a predetermined cycle in a linear direction connecting a diameter of a predetermined suction hole 22a in a direction perpendicular to the conveying direction to obtain an image. A linear image is arranged in time series to obtain a planar image, and a tablet in which defects such as cracks, chips, scratches, and deformation are found is discharged by a removing unit (not shown) on the downstream side. It is like this. In this case, the scanning line for imaging does not intersect with the peripheral edge of the suction hole 22a exposed from the gap between the transport belts 1.

Next, the individual actions and effects of the apparatus of the above embodiment will be described. The suction holes 22a can be extremely easily formed by punching the guide plate 22 made of sheet metal or the like at one time. As in the case of forming a slit by bridging the adjacent suction holes 22a, There is no step. Therefore, even if a thin metal plate is used as the guide plate 22a, sufficient accuracy can be ensured and assembly accuracy is not required, so that the manufacturing cost can be significantly reduced. Further, since the accuracy after assembling can be maintained satisfactorily, no special maintenance is required, which is advantageous in running cost.

Since the conveyor belt 1 is a timing belt, it does not slip in the conveyor direction and the lateral displacement is restricted by the engagement between the groove 11 and the guide rail 23. As a result, the conveyance belt 1 is prevented from vibrating and the pair of conveyance belts 1 facing each other are prevented from approaching each other by the suction action. It is possible to prevent the occurrence of rotation and twist and reliably prevent the occurrence of inspection errors due to them.

Further, since the diameter of the suction hole 22a is larger than the gap between the pair of conveyor belts 1, even if the fragments of the tablet T fall from the gap, most of them are sucked from the suction hole 22a into the suction chamber of the suction box 2. 26, and the suction hole 22a and the suction hole 22a
Even if it falls in the area between and, if it is a certain size or more, it is extremely unlikely that it will lose its balance and catch debris. Therefore, the fragments having a size that protrudes above the conveyor belt 1 may be the suction holes 22a and the suction holes 22a.
It is extremely rare to ride on the part between and, and even if this happens, if the fragments are just riding, they will be clamped between the slits and fixed. Unlike the above, since it receives a fixing force, it does not hit the tablet T and is repelled and does not affect the inspection.

Further, the fragments caught between the conveyor belts 1 are transferred together with the conveyor belt 1 and are sucked and removed when they enter the suction chamber 26. Alternatively, a rotating brush for cleaning or the like may be provided on the downstream side of the transport path to surely and easily remove the brush. Now consider a powder in which the pieces of tablet T are more finely crushed. First, even if the powder adheres to the conveyor belt 1, these powders are not removed by suction in the suction chamber 26 or by being reliably removed by the rotating brush or the like, so that an inspection error occurs. Can be easily prevented. Further, even if the powder adheres to the periphery of the suction hole 22a, as described above, the edge of the suction hole 22a is hidden in the shadow of the conveyor belt 1 on the scanning line of the imaging device, so that the suction hole 22a is not covered. The powder adhering to the surface is not imaged, and therefore the occurrence of inspection errors can be prevented.

In addition, the conveyor belt 1 has adjacent suction holes.
When the suction holes 22a are transferred while being supported by the bridging portions between the 22a and are circular suction holes 22a as in the present embodiment, only the same portion of the conveyor belt 1 may continuously hit the edge of the suction holes 22a. Since it is not present, wear due to the edge of the suction hole 22a can be prevented. In addition, the powder of the tablets T is the conveyor belt 1
Even if the powder adheres to the transportation path surface of the conveyor belt, the powder is scraped out in the transportation direction by the teeth of the transportation belt 1 so that the cleaning effect is high and the transportation belt 1 and the guide plate 22 are prevented from being worn by the powder. It also has excellent durability.

Although it is considered that the suction negative pressure is weakened above the bridging portion of the adjacent suction holes 22a as compared with the portion directly above the suction hole 22a, the guide of the conveyor belt 1 with respect to the length of the bridging portion. By setting the ratio of the height from the upper surface of the plate 22 to be larger than a certain degree, the influence can be sufficiently mitigated, and between the teeth on the inner peripheral side of the conveyor belt 1 and the guide rail 23. Since the suction negative pressure between the transport belts 1 can be made sufficiently uniform by the buffering action of the space formed in the above, it is possible to prevent the tablet T from vibrating.

FIG. 8 is a diagram showing an outline of a system for inspecting the surface of a tablet for printing and the damage state including the device having the above-mentioned structure.
Is a side inspection unit. The outline of the inspection system will be described. The tablets T stored in the hopper 110 are supplied to the conveyor belt 121 of the supply unit 120 through the hopper discharge port 111, and first, the tablets T that have been chipped off here are sifted off, and then the alignment unit is arranged.
The tablets T, which have been supplied to the sheet 130 and then have a substantially constant interval by the first conveyor belt 141, are in an upward posture by the first conveyor belt 141 of the first tablet conveyor 140, and are in the front-back inspection section.
Transported to 200. Even if the intervals between the tablets T are not uniform, the function of the front / back inspection unit 200 is not hindered.

The tablets T supplied by the first conveyor belt 141 in the upward posture lose the suction force of the first conveyor belt 141 at the end of the belt, and at the same time, the second tablet conveyor device 210 conveys the tablets T to the second conveyor. The one-dimensional image pickup device 220 picks up an image of the back surface while being sucked upward at that position by the belt 211 and being sucked and conveyed in a downward posture. in this way,
Since the transfer from the first transfer belt 141 to the second transfer belt 211 is only the vertical movement due to the switching of the vertical suction force, the posture is disturbed as seen in the first embodiment. The feature is that the tablets T do not remain and can be transferred in a stable and reliable manner.
The tablets T sucked and transported by the second transport belt 211 are transferred to the third transport belt 231 of the third tablet transport device 230 in the same manner, and the surface is imaged by the one-dimensional imaging device 240 while being transported in the upward posture. To be done. The defective product detected here is selectively discharged by the discharging device 250.

The tablets T, which have been inspected on the front and back, are next tested on the side surface.
The tablet T is sent to the 300, and the posture conversion unit 310 converts the tablet T from a flat posture to a standing posture and inspects all sides by the one-dimensional imaging device 320. The defective device is selectively discharged by the discharging device 330, and the good product is a good product. It is discharged by the discharge duct 340. Further, the side inspection unit 300 is provided with a suction / discharge device 350 for the powder of the tablet T.

In this inspection system, among the first to third tablet conveying devices 140, 210 and 230 according to the present invention, the first and third tablet conveying devices 140 and 230 are the same as those in the embodiment shown in FIGS. The sample testing apparatus having the configuration of the transporting section can be used as it is, and the second tablet transporting apparatus 210 can also have the configuration in which the vertical positional relationship is changed. Further, for the supply unit 120 and the alignment unit 130, for example, the technique of the supply unit 13 and the alignment unit 20 disclosed in Japanese Patent Application No. 63-259499 by the present applicant can be used as it is, and the side inspection unit 300 is also the same. Wish sho 63-152373
The technology of No. can be used as it is.

[0033]

As described above, according to the present invention, the surface inspection of a subject is prevented with the highest possible inspection accuracy while avoiding the possible occurrence of inspection errors due to various factors. In addition, it has a wide variety of effects such that it can be performed at high speed, has excellent durability, and can be formed of materials at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a subject inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the same device.

FIG. 3 is an enlarged cross-sectional view of a main part of the same device.

FIG. 4 is a plan view of the same device.

FIG. 5 is a vertical cross-sectional view of the same apparatus in the object transport direction.

FIG. 6 is a vertical sectional view of the same device in a direction perpendicular to the above.

FIG. 7 is a front view showing a schematic configuration of a tablet inspection system using the same device.

[Explanation of symbols]

 1 Transport Belt 2 Suction Box 4 Imaging Device 11 Recessed Groove 22 Guide Plate 22a Suction Hole 23 Guide Rails 24, 25 Timing Pulley 26 Suction Chamber 28 Drive Motor

Claims (1)

[Claims] 1. A suction box in which a negative pressure is introduced into an internal space by a negative pressure source, and a suction hole row which is attached so as to cover an opening surface of the suction box and which has a large number of suction holes opened at regular intervals in a linear direction. A guide plate provided with one or more rows and provided with convex guide rails on both sides of the suction hole row as a center, and on both sides of the guide plate outside both ends in the suction hole row forming direction, the suction box A timing pulley which is rotatably supported and one of which is driven to rotate by a drive source, and an annular timing belt whose both ends engage with the timing pulley and which has a central portion in the width direction of the inner peripheral surface. An annular groove is formed on the inner side of the guide rail to engage with the guide rail. The suction hole is a circle whose peripheral edge is centered at least at the center of the suction hole and whose diameter is a gap between opposite side edges of a pair of conveyor belts on both sides of the suction hole row. And a conveying portion formed to have a size outside the outer diameter of the pair and setting a length of a portion bridging between adjacent suction holes to be equal to or less than a gap between opposite side edges of the pair of conveying belts. And located at a position outside the predetermined suction hole and facing a subject to be transported while being seated across a pair of transport belts, and passing through the vicinity of the center of the suction hole. The linear image of the subject is captured by periodically performing reciprocal scanning in a linear direction that does not intersect with the peripheral edge exposed from the gap of the transport belt, and the linear image is connected in time series to the subject. An object inspection apparatus, comprising: an imaging unit that obtains a surface image.