JP4050942B2 - Appearance inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an appearance inspection apparatus for inspecting wrinkles and dirt on the surface of a test object such as a tablet, and in particular, images the appearance of the test object with an imaging device while transporting the test object on a transport belt. The present invention relates to an appearance inspection apparatus that performs inspection.
[0002]
[Prior art]
Conventionally, a test object such as a tablet is placed on the transport surface of the transport belt, and reflecting members such as prisms are arranged on both the left and right sides of the test object, and a reflected image whose optical path is changed upward through the prism. There is one that performs an appearance inspection by imaging.
The applicant of the present application has already disclosed an appearance inspection apparatus using two transfer drums in Japanese Patent No. 3273208.
[0003]
[Problems to be solved by the invention]
However, in the prior art described above, the lower edge portion (corner portion) of the test object comes into contact with the conveyance surface of the conveyance belt, resulting in a blurred image, and chipping or dust of the edge is attached. It was difficult to detect such a state.
Further, in the above-mentioned Japanese Patent No. 3273208, an appearance inspection apparatus using two conveyance drums is advantageous in that an appearance inspection of a test object in which conveyance drums are arranged in a plurality of rows can be performed at the same time, although the cost is low. The curved drum centered on the head has a problem in that the shape of the test object that can be transported is limited, for example, the deformed tablet is not placed on the transport surface and is not stable, and the versatility of the drum is slightly affected.
[0004]
The present invention has been made by paying attention to such a conventional problem, and using the transport belt, the test object is not limited in shape and is stably transported, while the edge on the transport surface side of the test object side surface is provided. It is an object of the present invention to provide a highly versatile appearance inspection apparatus capable of clearly imaging and inspecting a portion.
[0005]
[Means for Solving the Problems]
For this reason, the invention according to claim 1
In the appearance inspection apparatus that inspects the appearance of the test object with the imaging device while transporting the test object on the transport belt,
A cross-sectional shape orthogonal to the conveyance direction of the conveyance belt,
The central part of the transport surface on which the test object is placed is formed flat, and both end edges of the flat part are positioned on both outer sides in the transport direction than the test object, and both end edges of the flat part are on both outer sides in the transport direction. The taper is provided in the direction in which the belt thickness decreases toward the surface.
[0006]
According to the invention of claim 1,
The part that is likely to become a blind spot close to the conveyance surface of the test object is released by providing a taper on the cross-sectional shape of the conveyance belt on both outer sides in the conveyance direction of the test object placed on the flat part (central part of the conveyance surface) . By forming the space, imaging can be performed and inspection accuracy is improved.
The invention according to claim 2
A side image of the test object is captured by the imaging device.
[0007]
According to the invention of claim 2,
Since it is possible to capture an image of the object viewed from the side, it is not necessary to capture images that are unnecessary for the inspection process, i.e., powder or dust remaining on the conveyor belt as inspection images. It is not necessary to mask an unnecessary image in the process, and the inspection process can be simplified. It also leads to improved inspection accuracy.
[0008]
The invention according to claim 3
An illumination member that illuminates the test object and a reflection member that guides a reflected light image from the test object to the imaging device are arranged on the side of the test object.
According to the invention of claim 3,
By illuminating the test object from the side with the illumination member, the reflected light image from the test object is guided to the imaging device through the reflection member, so that a clear image of the test object can be captured, and the optical path is reflected by the reflection member. And the image pickup apparatus can be installed at an appropriate position such as the upper side or the lower side of the conveyor belt.
[0009]
The invention according to claim 4
A negative pressure passage for introducing a negative pressure to the center of the conveyance surface is formed so as to adsorb the test object on the conveyance belt.
According to the invention of claim 4,
The test object can be attracted to the transport surface of the transport belt and transported in a stable posture, and a blur-free image can be obtained, thus ensuring high inspection accuracy.
[0010]
The invention according to claim 5
The conveying belt is configured by a pair of timing belts disposed on both sides with a gap serving as the negative pressure passage interposed therebetween.
According to the invention of claim 5,
A negative pressure is continuously supplied in the conveying direction from a gap between a pair of timing belts that are driven at a constant speed in synchronization with each other, and even a curved object can be conveyed in a stable posture.
[0011]
The invention according to claim 6
A taper is provided in a direction in which the belt thickness decreases toward the inner center at the center of the transport surface of the transport belt.
According to the invention of claim 6,
Even in the case of a test object such as a curved surface, the peripheral portion thereof can be supported on the edge of the taper and placed on the transport surface in a stable posture.
[0012]
The invention according to claim 7
It is characterized by including a supply aligning unit that aligns and guides the test object at the center of the transport surface of the transport belt.
According to the invention of claim 7,
By guiding the test object to the transport belt while being aligned by the supply alignment unit, stable transport can be performed regardless of the shape of the test object, and versatility is improved.
[0013]
The invention according to claim 8 is
The supply alignment section;
An alignment conveying path for aligning while conveying small articles;
A reduction conveyance path that receives small articles discharged without passing through the alignment supply port provided on the downstream side of the alignment conveyance path and returns them to the upstream side of the alignment conveyance path, and The conveyance path is characterized in that the small article is conveyed by a belt, and the small article is aligned by a side wall formed so as to be shielded obliquely with respect to the conveyance direction.
[0014]
According to the invention of claim 8,
The test object is guided to the side wall of the alignment conveyance path, and is transferred to the subsequent conveyance belt while being aligned so as to fill the excess gap.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overview of the entire device. The tablet T, which is a test object, from the hopper unit 11 is continuously troublesome by being given its own weight and vibration by the vibration generator via the first alignment feeder unit 12A and the second alignment feeder unit 12B. Supplied to the alignment supply unit 14.
[0016]
The alignment supply unit 14 has the tablets T in the center by side walls 14a and 14b installed obliquely with respect to the transport direction so as to gradually narrow the belt surfaces on both sides for transporting the tablets T from upstream to downstream. They are aligned and guided to the first transport unit 15A. Tablets T that have not been aligned by the alignment supply unit 14 are returned to the second alignment feeder unit 12B by a return belt 13 that is inclined upward.
[0017]
The first transport unit 15A sucks the tablet T from above with negative pressure, and thereby adheres and transports the tablet T onto a transport belt (timing belt) (not shown) located on the lower surface. A motor for driving the conveyor belt is also provided.
The second transport unit 15B is arranged upside down with the same structure as that of the first transport unit 15A. The second transport unit 15B sucks the tablet T from below by negative pressure and is placed on the transport belt (timing belt) on the upper surface. Secure and transport. There is a region where the end portion of the first transport unit 15A and the start end portion of the second transport unit 15B overlap, and the suction hole of the first transport unit 15A is eliminated in this region, and is relatively stronger than the first transport unit 15A. By applying negative pressure, the delivery of the tablet T can be performed smoothly. In addition, according to the magnitude | size of the tablet T, the space | interval of 15 A of 1st conveyance parts and the 2nd conveyance part 15B can also be adjusted suitably.
[0018]
When the test object is a tablet T as in this embodiment, the shape thereof is various as shown in FIG. 6 such as a flat tablet, a lock with R, a sugar-coated tablet, and a deformed tablet. In a conventional drum-type inspection device (for example, Japanese Patent No. 3273208), flat locks, R-attached locks, and sugar-coated tablets can be placed on a transport drum. I can't. On the other hand, in the inspection apparatus according to the present embodiment, even if it is a deformed tablet, the direction is set to the transport direction while being guided along the side edges of the side walls 14a and 14b in the supply alignment stage described above. Stable transport can be performed regardless of the shape of the tablet T by being sent to the transport unit so that the longitudinal direction is always directed and by being combined with the transport unit using the transport belt. Thereby, the versatility with respect to a test object is higher than before.
[0019]
A first camera 16A and a second camera 16B serving as imaging devices are installed below the first transport unit 15A and above the second transport unit, respectively. The first camera 16A and the second camera 16B may use low-cost CCD line sensors as will be described later, but may be CCD cameras that shoot on a normal surface as necessary. The image data captured here is processed by binarization processing, differentiation processing, connected component processing, area or length comparison processing, shape comparison processing, and the like by an inspection processing unit (not shown). Appearance inspection is carried out by performing various processes that emphasize the presence / absence of products, the presence / absence of abnormal shapes such as chips and scratches, and the presence / absence of foreign matter and dirt.
[0020]
A first illumination / reflection device 17A is provided between the first camera 16A and the first transport unit 15A, and a second illumination / reflection device 17B is provided between the second camera 16B and the second transport unit 15B. The first illumination / reflecting device 17A and the second illumination / reflecting device 17B internally reflect an illumination member that illuminates the tablet T, which is a test object, and a reflected light image from the side of the illuminated tablet T. And a reflecting member that leads to the first camera 16A and the second camera 16B. Here, in order to illuminate the tablet T uniformly, the illumination member is provided with a ring shape so as to surround the test object as a center. That is, what was conventionally illuminated from diagonally above is illuminated from the side of the tablet T in this embodiment.
[0021]
The sorting / sorting unit 18 is a part that sorts non-defective products and defective products in accordance with a control signal from an inspection processing unit (not shown). For example, when a defective product is found, if the test object such as the tablet T is easily damaged, it is forcibly dropped by an air nozzle that injects high-pressure air. The sorting mechanism is not limited to this, and a sorting claw provided inside may be forcibly dropped onto the defective product chute 20C by an ON operation of the solenoid.
[0022]
The uninspected shutter 19 is for guiding the tablet T that has leaked into the inspection in the transport unit to the uninspected product chute 20B. The operation is a mechanism in which when an uninspected product flows, the shutter goes down, blocks the non-defective product chute 20A, and is forcibly guided to the uninspected product chute 20B.
The tablets T selected and sent to the non-defective product chute portion 20A, the uninspected product chute portion 20B, and the defective product chute portion 20C are guided to the respective storage boxes.
[0023]
FIG. 2 is an external view of a transport unit according to the present invention. The conveyor belt 21 has a configuration in which a pair of timing belts that are moved at a constant speed in synchronization with each other are arranged in two rows with a small gap. The tablet T is placed so that the center of the tablet T is positioned in this small gap, and a negative pressure is guided to the gap to firmly fix the tablet T on the transport belt 21 and transport it while maintaining a stable posture. In the present embodiment, two sets of transport belts 21 having such a configuration are arranged in parallel in the horizontal direction.
[0024]
FIG. 3 is a longitudinal sectional view of the periphery of the second transport unit 15B. Since the structure around the first conveyance unit 15A is the same as the structure upside down, the description thereof is omitted.
The tablet T is placed on the transport belt 21, and the reflecting member 171 is provided in a right and left direction perpendicular to the transport direction. As a result, the side image of the tablet T is reflected toward the second camera 16 </ b> B installed above, and the CCD line sensor 162 is imaged through the lens 161. 3 and 4, for convenience of description, a simple configuration using 1 to 3 reflecting members has been described. However, in actuality, a side view of the tablet T is used in a camera using 5 reflecting members. The details will be described later.
[0025]
A negative pressure chamber 151 for generating negative pressure is provided below the conveyor belt 21, and the tablet T is fixed by suction through a plurality of suction holes 152 provided in the conveyance direction. Yes.
The cross-sectional shape of the conveyance belt 21 is generally flat on the entire area of the conveyance surface, but in this embodiment, only a part of the vicinity of the suction hole is made flat and tapered toward both sides. The shape is cut into Further, the reflection member 171 described above is arranged directly beside the tablet T so that the image can be clearly displayed. This facilitates extraction of defects such as chipped edges of the tablet T.
[0026]
FIG. 4 shows the arrangement of the first, second, and third reflecting members at the imaging position of the tablet T. The first reflecting member 171a is disposed on a point of 45 degrees with respect to the transport direction, and the second reflecting member 171b and the third reflecting member 171c (prism) are disposed on a point of 90 degrees on the left and right with respect to the transport direction. Yes.
The first reflecting member 171a can project a range of 120 degrees around an axis of 45 degrees with respect to the transport direction. Therefore, a range of 240 degrees can be covered by the two first reflecting members 171a (upper left and lower right in FIG. 4). If this arrangement is performed on one side of the first conveying unit 15A and the second conveying unit 15B and arranged on the other side so as to be symmetric, the side surface of the tablet T can be inspected over the entire circumference without a blind spot.
[0027]
FIG. 5 shows a detailed cross-sectional shape of the conveyor belt.
The case where the tablet T is mounted on the conveyance belt 21 is shown. Tapered cuts (tapered surfaces 21a) are provided on both the left and right ends, whereby the side surface of the tablet T can be clearly imaged and inspected. Further, a small taper cut (taper surface 21b) is also provided in the vicinity of the suction gap at the center of the cross section. Thereby, even if it is a case where tablet T (sugar-coated tablet etc.) is mounted as a test object, stable conveyance can be performed.
[0028]
In addition, the width of the suction gap can be appropriately adjusted according to the size of the tablet T to be conveyed.
[Brief description of the drawings]
FIG. 1 is an external view showing the overall configuration of an appearance inspection apparatus according to an embodiment of the present invention.
FIG. 2 is an external view of a transport unit of the apparatus.
FIG. 3 is a longitudinal sectional view of the periphery of the transport unit.
FIG. 4 is a diagram showing an arrangement of reflecting members at an imaging position of a test object.
FIG. 5 is a diagram showing a detailed cross-sectional shape of a conveyor belt.
FIG. 6 is a diagram showing the form of various tablets.
[Explanation of symbols]
12A ... 1st alignment feeder part 12B ... 2nd alignment feeder part 14 ... Alignment supply part 14a, 14b ... Side wall 15A ... 1st conveyance part 15B ... 2nd conveyance part 16A ... 1st camera 16B ... 2nd camera 17A ... 1st Illumination / reflecting device, 17B ... Illuminating / reflecting device 21 ... Conveying belt 21a ... Outer tapered surface 21b ... Inner tapered surface 151 ... Negative pressure chamber 171a ... First reflecting member, 171b ... Second reflecting member, 171c ... Third Reflective member

Claims (8)

In the appearance inspection apparatus that inspects the appearance of the test object with the imaging device while transporting the test object on the transport belt,
A cross-sectional shape orthogonal to the conveyance direction of the conveyance belt,
The central part of the transport surface on which the test object is placed is formed flat, and both end edges of the flat part are positioned on both outer sides in the transport direction than the test object. An appearance inspection apparatus having a taper shape in a direction in which the belt thickness decreases.   The appearance inspection apparatus according to claim 1, wherein a side image of a test object is captured by the imaging apparatus.   3. An appearance inspection according to claim 2, wherein an illumination member that illuminates the test object and a reflection member that guides a reflected light image from the test object to the imaging device are arranged on a side of the test object. apparatus.   The external appearance according to any one of claims 1 to 3, wherein a negative pressure passage for introducing a negative pressure is formed in a central portion of the conveyance surface so as to adsorb the test object on the conveyance belt. Inspection device. The appearance inspection apparatus according to claim 4, wherein the conveyance belt includes a pair of timing belts disposed on both sides of a gap serving as the negative pressure passage.   The appearance according to any one of claims 1 to 5, wherein a taper is provided in a direction in which a belt thickness decreases toward an inner center at a center portion of the transport surface of the transport belt. Inspection device.   The appearance inspection apparatus according to any one of claims 1 to 6, further comprising a supply alignment unit that aligns and guides the test object to a central portion of the conveyance surface of the conveyance belt. The supply alignment unit includes:
An alignment conveying path for aligning while conveying small articles;
A return conveyance path that receives small articles discharged without passing through the alignment supply port provided on the downstream side of the alignment conveyance path and returns them to the upstream side of the alignment conveyance path, and
8. The appearance inspection apparatus according to claim 7, wherein the alignment conveying path conveys the small articles by a belt and aligns the small articles by a side wall formed so as to be shielded obliquely with respect to the conveyance direction. .

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