JPH0312254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic surface inspection device, and more specifically, to an automatic surface inspection device that is particularly effective in automatically inspecting the inner surface of paper cups. So, the term "paper cup"
means a cup made of paper or a material with similar properties to paper, and also includes a cup whose surface has been coated.

Paper cups are commonly used as containers for vending machines and are widely used as containers for various foods. In these applications, insects, hair,
Of course, if there is oil or the like on the container, it cannot be used as a food container, but even in the case of something generally harmless, such as chips, there is a tendency to be reluctant to use it. For this reason, there is a high demand for inspecting the inner surface of molded paper cups for dirt, and visual inspections have been carried out by humans as necessary. Experienced people have a high degree of freedom in judgment and are superior in terms of processing time, accuracy, and economy even when testing items are wide-ranging. It has disadvantages such as being easily influenced by preconceptions, being easily influenced by one's mood at the moment, and not being able to continue working at a constant pace for long periods of time because it cannot be said that dirt will be overlooked due to fatigue. Therefore, automation of testing has been desired. This is because if automatic inspection equipment can be used in place of human visual inspection, it will be possible to ensure a certain level of accuracy and objectivity in the inspection results, and at the same time it will save labor and enable long-term continuous operation. can.

An automatic paper cup inspection device requires a transport device to transport the paper cup and position it at the inspection position, a detection processing device to detect the surface of the paper cup and process the detection data to determine pass/fail. seems to be necessary.

First, considering the conveyance device, JP-A No. 50-57291 is used in an automatic glass bottle inspection device that detects scattered light from scratches by shining a laser beam on the glass bottle while rotating it at the inspection position. A rotary table type conveying device as disclosed in the publication comes to mind. This rotary table type conveyor is equipped with a feeder screw and star wheel to feed the bottles onto the rotary table, a friction belt to automatically move the bottles placed on the rotary table, etc., all of which correspond to bottles. It is designed to make contact with a certain amount of force. However, paper cups have less mechanical strength than gas bottles, and when contacted with such considerable force, they deform and, in extreme cases, break. Therefore, the conveying device must not apply strong force to the paper cup.
On the other hand, in order to inspect the inner surface of a paper cup with a fixed surface inspection device, it is necessary to always position the paper cup in a fixed position. You need to rotate the paper cup. However, the above-mentioned transport device for glass bottles rotates the bottle by rubbing the side of the bottle with a friction belt, and the paper cup is deformed or crushed, and even if it is not deformed, the paper cup is The tapered surface may cause uneven lifting or the center axis may be tilted significantly.
If the paper cup is deformed, lifted up, or has a large inclination, the surface of the paper cup cannot be accurately compared with the inspection pattern. As described above, conventional conveying devices cannot meet the special characteristics of paper cups and cannot be used for paper cups at all.

Furthermore, in the method of rotating the paper cup when it reaches the inspection station, it takes time for the paper cup to rotate at a predetermined speed. However, it is preferable that this acceleration time not be provided in order to speed up the surface inspection of the paper cup. Therefore, a method of accelerating in advance can be considered, but the conventional method is undesirable because the structure becomes complicated.

Next, consider the detection processing device. Recent advances in image processing technology have made it possible to detect and distinguish even small defects on the outer surface of an object to be inspected. However, the inner surface of a paper cup is not only difficult to see, but it is also necessary to detect extremely small dirt, for example, about 0.1 mm in size. however,
Conventionally, such extremely small defects could not be reliably detected and discriminated because it was difficult to distinguish them from noise. To make this possible, it is necessary not only to increase the resolution of surface detection devices such as imaging cameras, but also to effectively remove noise and emphasize minute defects to provide clear contrast. Furthermore, since the image information of the paper cup includes not only the background but also information that is not a defect such as seams, marks, and irregularities, it is necessary to effectively separate these. Furthermore, when it is necessary to process a large amount of image data, such as processing an image of the inner surface of a paper cup, a computer has conventionally been used. However, when a computer is used, processing is performed by software, which slows down the processing speed and is not suitable for high-speed processing.

Furthermore, if we look at the paper cup in detail, we can see that the paper cup has at least a top edge, a seam between the sides and the bottom, and a side seam, and in some cases, the bottom has a hole for a straw and is made of metal foil that can be easily peeled off. It's blocked.
However, these seams, edges, and holes, which are detected by imaging the paper cup, are not dirt and must be distinguished from dirt. In such a case, a method is used in which detection data corresponding to portions such as seams is subjected to dead zone processing, that is, mask processing. In order to ensure reliable mask processing, the range of the mask must be widened to some extent so that even if there is an inaccuracy in the position of the paper cup or a misalignment of the surface inspection device, seams and the like can be masked. However, with this method, even the actual dirt is masked and cannot be detected, making it impossible to detect dirt with sufficient reliability.
In other words, in the past, if there was a portion of the surface to be inspected that should be masked, there would be a portion where the stain detection process was not performed due to the masking process, making complete stain detection impossible.

Also, if the paper cup is positioned so that the side seam of the paper cup is along the main scanning direction of the surface inspection device,
The other top edges and the seams between the side and bottom surfaces are perpendicular to the main scanning direction. However, in the past, in addition to effectively masking the parts that should be masked along the main scanning direction and the parts that should be masked along the direction perpendicular to the main scanning direction, the entire surface was covered with no parts that were not subjected to dirt detection processing. However, there is no method that can completely detect dirt.

Furthermore, in order to mask the detected data, a reference axis is required for comparing the mask pattern and the detected data. However, detecting the entire paper cup after detecting the reference axis on the surface of the paper cup takes a long time for detection, and is not suitable for high-speed processing.

Therefore, the present invention has developed a transport device that can accurately position a paper cup at an inspection position without deforming it, and a detection processing device that can image the inner surface of a paper cup and detect even minute defects accurately and at high speed. An object of the present invention is to provide an automatic surface inspection device having the following features.

Another object of the present invention is to provide an automatic paper cup with a transport device capable of positioning the paper cup accurately in an inspection position without deforming it and allowing it to rotate at a constant speed at the inspection position without requiring acceleration time. The object of the present invention is to provide a surface inspection device.

Another object of the present invention is to provide an automatic surface inspection device having a conveying device that can reliably hold paper cups without deforming them, causing eccentricity or lifting, both during conveyance and rotation. This is what I am trying to do.

Still another object of the present invention is to provide an automatic surface inspection system having a detection processing system that eliminates areas that are completely masked to ensure contamination detection.

Another object of the present invention is to enable reference memory for the mask pattern of the upper bent portion of the side seam only for that mask pattern, and to enable real-time processing. The present invention aims to provide a simple automatic surface inspection device.

Furthermore, another object of the present invention is to provide an automatic surface inspection system having a detection processing device that minimizes the time required for automatic paper cup detection by effectively utilizing detection data before detection of a reference axis for mask processing. The aim is to provide the equipment.

That is, the automatic surface inspection device according to the present invention includes a paper cup transport device that positions a paper cup at a detection station, a surface detection device that detects the surface of the paper cup at the detection station, and a detection process that processes detection data to determine dirt. It consists of a device. The conveyance device includes a rotary indexing table that is driven intermittently, and is arranged around the indexing table and supported so as to be able to rotate relative to the indexing table, and tightly receives the lower part of the paper cup. A cup holder having a concave portion, a sun gear that is rotatably and coaxially mounted on the rotation axis of the index table and continuously driven, and a planet that is fixed to the rotation axis of the cup holder and meshes with the sun gear. a supply station in which a gear is disposed, a supply means for supplying a paper cup to the cup holder; an inspection station for holding and inspecting a paper cup in the cup holder; and discharging the paper cup from the cup holder based on a pass/fail result. distributing and discharging means, the paper cup held in the cup holder is rotated together with the indexing table by the rotation of the indexing table, and is also transported through the planetary gear by the continuous rotation of the sun gear. It is adapted to rotate at a constant speed independently of the rotation of the index table. The surface detection device is arranged to scan the paper cup along a scanning line substantially coplanar with the rotation axis of the paper cup, and an illumination means for illuminating the paper cup rotating on its own axis in the inspection station. It is equipped with a line sensor composed of a solid-state image sensor, and outputs an analog pixel signal.

The detection processing device also includes a preprocessing section that receives the analog pixel signal output from the front surface detection device, shapes the waveform, converts it into digital data, and outputs the signal.
and a data processing section that receives digital pixel signals from the preprocessing section and performs dirt detection, and the data processing section receives digital pixel signals from the preprocessing section and processes pixel data in the main scanning direction. a detection axis conversion circuit that converts the pixel data into sub-scanning direction pixel data; a main scanning direction reference coordinate setting circuit that receives the digital pixel signal from the detection axis conversion circuit and detects a reference axis in the main scanning direction; and the preprocessing. a sub-scanning direction reference coordinate setting circuit that receives digital pixel signals from the preprocessing section and detects a reference axis in the sub-scanning direction; and a sub-scanning direction reference coordinate setting circuit that receives digital pixel signals from the preprocessing section and detects a reference axis in the sub-scanning direction. a direction reference coordinate setting circuit; a mask pattern circuit that receives digital pixel signals from the preprocessing section to create pattern information of portions to be excluded from dirt detection targets; and a mask pattern circuit that receives digital pixel signals from the preprocessing section to create a mask. For the parts to be detected, a main scanning direction dirt detection circuit having a first judgment circuit that performs a dirt detection process in the main scanning direction while performing mask processing in response to mask information from the mask pattern circuit, and the detection axis conversion circuit. For the part to be masked by receiving digital pixel signals from the mask pattern circuit, the sub-scanning direction dirt detection circuit has a judgment circuit 2 that performs a dirt detection process in the sub-scanning direction while performing masking processing in response to mask information from the mask pattern circuit. a detection processing device comprising a circuit and a comprehensive judgment circuit that receives contamination information from the first and second judgment circuits and makes a comprehensive pass/fail judgment, and based on the comprehensive judgment result,
A sorting and discharging device of the paper cup conveying device is used to separate non-defective products from defective products.

In the automatic surface inspection device as described above, the paper cup conveying device holds the paper cup using a cup holder having a recess that tightly receives the lower part of the paper cup, so there is no possibility of deforming the paper cup by applying strong external force. Instead, the paper cup can be transported by the cup holder to the inspection position and rotated there. At that time, the paper cup does not lift up or become eccentric with respect to the axis of rotation.

Furthermore, the rotation of the indexing table causes the paper cup held in the cup holder to revolve together with the indexing table and to be positioned at the inspection station, and the continuous rotation of the sun gear causes the paper cup to be positioned at the inspection station via the planetary gears. Since the paper cup is rotated at a constant speed independently of the rotation of the indexing table, there is no need for acceleration time for the rotation of the paper cup at the inspection position, making high-speed processing possible.

Furthermore, since the detection processing device of the automatic surface inspection apparatus according to the present invention performs dirt detection processing in both the main scanning direction and the sub-scanning direction, it is possible to reliably detect dirt. Parallel seams are detected as dirt and therefore need to be masked, but parallel seams are not detected as dirt and are therefore processed without being masked. Therefore, there is no masked part in both the main scanning direction and the sub-scanning direction when detecting dirt, so by integrating the dirt detection in both directions, the masked part can be virtually eliminated and the dirt cannot be detected. can be detected without exception.

In one embodiment of the automatic surface inspection device according to the present invention, a hole is formed in the bottom of the cup holder of the conveying device, which communicates with a hollow chamber of the rotating shaft, and the hollow chamber of the rotating shaft communicates with a vacuum source. Thus, the paper cup is reliably held by suction on the cup holder. A pushing mechanism is also provided for pushing and properly positioning a paper cup received in the cup holder. This paper cup pushing mechanism is constructed to include a piston cylinder device and a pushing disk that is driven up and down by the piston cylinder device.

Furthermore, in a preferred embodiment of the invention, the conveying device is provided around the indexing table at least in the order of a supply station, an inspection station and a discharge station, the supply means being provided in the supply station, and A hole is formed in the bottom of the cup holder, a hollow chamber having a communication hole communicating with the hole in the bottom of the cup holder and extending in a radial direction is formed in the rotation axis of the cup holder, and the index table is formed with a hole in the rotation axis of the cup holder. , a boss member is fixed that rotatably holds the rotation axis of the cup holder and has an annular channel surrounding the radial hole, and further has a hole communicating with the annular channel on the revolution axis of the indexing table. A second annular member is fixed to the first annular member, and a second annular member is provided with a hollow chamber that is open to the first annular member and extends in the circumferential direction so as to selectively communicate with the hole of the first annular member. An annular member rotatably receives the revolution axis and is fixedly supported by the frame of the apparatus, and a hollow chamber of the second annular member extends in the circumferential direction so as to correspond to the supply station and the inspection station, and a vacuum source. a vacuum chamber connected to the dispensing station and a high-pressure chamber extending circumferentially and connected to a pressure source corresponding to the ejection station. After being suctioned and held, the cup continues to be suctioned and held until it reaches the inspection station, and when it reaches the discharge station, it is discharged from the cup holder. By doing this, the paper cup can be reliably held by suction and can be reliably ejected from the ejection station. Additionally, a pushing station is provided between the supply station and the inspection station, and a pushing mechanism is provided there for pushing the paper cup suctioned and held into the cup holder and positioning it appropriately. It may also be positioned within the cup holder.

In addition, the discharge station is divided into a defective product discharge station and a non-defective product delivery station, and the high pressure chamber of the second annular member is expanded in the circumferential direction so as to correspond to the defective product discharge station and is connected to the first valve. a first high-pressure chamber connected to a pressure source via a second valve, and a second high-pressure chamber extending circumferentially and connected to a pressure source via a second valve so as to correspond to the good product delivery station.
The first valve and the second valve may be selectively opened to separate paper cups into high-pressure chambers, thereby allowing paper cups to be sorted.

Furthermore, in one embodiment of the automatic surface inspection device according to the invention, the illumination means of the surface detection device comprises:
It is equipped with a point light source and a condensing cylindrical lens, and is designed to concentrate light on a narrow and narrow area in the scanning direction. In another embodiment, the illumination means includes a point light source and a cylindrical reflecting mirror for condensing light, and is configured to concentrate the light in an elongated area in the scanning direction. In yet another embodiment,
The illumination means includes a rod-shaped light source and a circular convex lens for condensing light, and is configured to concentrate light on an elongated area in the scanning direction.

Further, the illumination means is placed at a position away from a plane including the line sensor and the rotation axis of the paper cup so as to cast a shadow on the side seam of the paper cup.

Further, in the automatic surface inspection device according to the present invention, the surface detection device is arranged so as to image the paper cup from diagonally above, and the surface detection device is arranged so as to image the paper cup from diagonally above. The imaging plane of the line sensor is agitated to deepen the depth of field.

Furthermore, among the edges and seams of a paper cup, the side seam of the paper cup is the easiest to detect in parallel to the main scanning direction, so the sub-scanning direction reference coordinate setting circuit uses the side seam of the paper cup as the reference Detected as an axis. In a preferred embodiment of the present invention, the sub-scanning direction reference coordinate setting circuit includes a circuit that totals input digital pixel signals for each scanning line, and a reference line emphasis circuit that subtracts a certain value from the total value. , a circuit that calculates a dynamic average value of the output of the reference line emphasis circuit, a subtracter that subtracts the dynamic average value from the output of the reference line emphasis circuit, and an adder that adds the output of the subtracter and the reference value. When the adder output is 0 or negative, the scanning line is used as the reference line.
On the other hand, the main scanning direction reference coordinate axis setting circuit detects when the image signal changes from a dark state to a bright state after each scan starts, and masks the seam between the top edge and the side and bottom surfaces of the paper cup. A signal for processing is output to the first determination circuit.

Furthermore, in an embodiment of the device according to the present invention, the preprocessing circuit includes a first adder that calculates the sum g ₁ of digital pixel signals for pixels on the upper, lower, left, and right sides that are adjacent to each other in terms of coordinates with respect to the digital pixel signal E. and a second adder that calculates the sum g ₂ of the digital pixel signals for the pixels at the upper right, lower right, upper left, and lower left that are diagonally adjacent in coordinates to the digital pixel signal E, and g ₁ or (g ₁ + g ₂ )/2 as peripheral data g, a coefficient circuit that provides weighting coefficient K, and peripheral data g.
a second calculation circuit which receives the weighting coefficient K and the digital pixel signal E and calculates the contour emphasis signal (K+4)-g/K and the smoothed signal KE+g/K+4; and the contour emphasis signal and the smoothed signal. The contour emphasizing and smoothing circuit includes a selection circuit for selectively outputting the output.

Furthermore, in the embodiment of the automatic surface detection device of the present invention, the dirt detection circuit in the main scanning direction and the sub-scanning direction includes a first dynamic average value circuit for calculating a first dynamic average value of input digital pixel signals. a subtracter that subtracts the first dynamic average value from the input signal; and a circuit that slices the output of the subtracter at a sufficiently deep first threshold to detect highly concentrated dirt.
a second dynamic average value circuit that calculates a second dynamic average value from the subtracter output; and a second dynamic average value circuit that slices the second dynamic average value with a second threshold shallower than the first threshold to obtain a low concentration. A circuit that detects the range of dirt, a circuit that expands the range of dirt,
A dirt information extraction circuit is provided, which is configured to detect low-density dirt by slicing the subtracter output at a sufficiently shallow third threshold using this expanded range as an inspection section.

By using such a dirt information extraction circuit, both dark and light dirt can be reliably detected.

Further, the mask pattern of the upper bent portion of the side seam is stored in a first reference memory, and the dirt detection circuit performs sub-scanning of the mask pattern in the first reference memory from the start of scanning the paper cup. The stain detection is started with a delay of only a time corresponding to the length in the direction. Therefore, the reference memory that records the mask pattern has a capacity that is sufficient to cover the mask pattern, and processing can be performed in real time.

Furthermore, in a preferred embodiment of the automatic surface detection device according to the present invention, a dirt information memory and a mask matching circuit are separately provided for the inspection range where the position of the mask pattern is determined by the sub-scanning direction reference axis, and the sub-scanning direction Until the direction reference axis signal is received, the dirt information from the first and second determination circuits is stored in the dirt information memory, and after the sub-scanning direction reference axis is detected, the dirt information is stored in the first and second determination circuits as a mask. Performs mask processing based on pattern information, detects dirt information, and outputs it to a comprehensive judgment circuit,
After completion of scanning the entire range of the object to be inspected, the dirt information in the dirt information memory and the corresponding mask pattern in the reference memory are compared by the mask matching circuit, and the dirt information from the matching circuit is integrated. Output to the judgment circuit. If you do this,
It is no longer necessary to rotate the paper cup once after detecting the reference axis, and the time required to detect the surface of the paper cup can be shortened, allowing for faster inspection. and,
In this case, it is possible to simplify the comparison between the dirt information stored in the dirt information memory and the corresponding mask pattern in the reference memory by performing it in order from the highest address number to the lowest address number. Processing can be performed with a simple circuit configuration.

Embodiments of an automatic surface inspection apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of an automatic surface inspection device for inspecting the inner surface of a paper cup according to the present invention. This automatic surface inspection device includes a conveying device 10 that receives a paper cup, conveys it to an inspection position, and rotates it there, and a detection processing device that detects the inner surface of the paper cup and processes the detected data to determine pass/fail. 12. The detection processing device 12 includes a surface detection device 14 that detects the inner surface of the paper cup;
It has a processing determination device 16 that processes detection data from and determines the presence or absence of minute defects.

The conveying device 10 is shown in FIGS. 2 to 4. Second
The figure is a top view of the conveyance device 10, and FIG.
Fig. 4 is a partially omitted front view of Fig. 2;
It is a sectional view taken along the line - in the figure.

As can be seen from FIGS. 3 and 4, the conveying device 10 has a cup holder 22 having a recessed portion having an inner shape that is approximately the same shape and size as the outer shape of the paper cup 20. As shown in FIGS. The cup holder 22 preferably has a height that allows it to tightly hold a paper cup without causing any displacement, for example, a height that accommodates at least the lower half of the paper cup. If this cup holder 22 holds a paper cup, by rotating the cup holder 22, the paper cup can be rotated together. Furthermore, cup holder 2
Since the concave portion 2 has the same shape and dimensions as the outer shape of the paper cup, the center of the cup holder can be accurately aligned with the central axis of the paper cup, and the paper cup can be rotated around its central axis. can.

As shown in FIG. 2, for example, six cup holders 22 are arranged around the circular indexing table 24 at equal angular intervals. The indexing table 24 is fixed to a rotating shaft 28 that is rotatably supported by the frame 26 of the conveying device 10. Six bosses 30 are fixed around the indexing table 24 at intervals of 60 degrees, and an autorotation shaft 34 is rotatably supported by the bosses 30 via bearings 32.
A flange 36 is formed at the upper end of the rotation shaft 34, and a cup holder 2 is attached to the flange 36.
2 is fixed with a screw 38. Therefore, the cup holder 22 can be replaced according to the size and shape of the paper cup. In addition, cup holder 2
2 is rotatable around the index table 24.

In FIG. 2, is a feeding station, is a pushing station for firmly pushing the paper cup into the cup holder, and is a
is an inspection station, is a spare station, is a defective product discharge station, and is a delivery station. Therefore, the cup holder 22 that has reached the inspection station due to the intermittent rotation of the indexing table must be rotated there because the detection device is of the scanning type. On the other hand, for high-speed inspection, the time from when the cup holder 22 rotates on its own axis until it reaches constant rotation speed at the inspection station must be minimized as much as possible. Therefore, as described above, a method of accelerating the cup holder by giving it rotation on its own axis in advance at a station one station before the inspection station can be considered. As one means of doing so,
It is conceivable to provide a friction wheel similar to the one in frictional contact with the circumferential surface of the flange 40 of the cup holder 22 to rotate the cup holder 22 at a station preceding one of the inspection stations. However, such a method is not preferable because the friction portion is worn out, requiring frequent replacement of the friction wheel, and the structure becomes complicated.

Therefore, in this embodiment, the planetary gear 42 is attached to the cup holder, and the planetary gear 42 is attached to the fifth gear.
It is rotated by a sun gear 44 placed in a positional relationship as shown in the figure. That is, as shown in FIG. 4, a planetary gear 42 is fixed to the lower end of the rotating shaft 34, and a sun gear 44 meshing with the planetary gear 42 is mounted on the rotating shaft 28 via a bearing 46. A gear 48 that rotates together with the sun gear 44 is also attached to the rotating shaft 28 via a bearing 46.
and the gear 48 are rotatable with respect to the rotating shaft 28,
That is, it is made to be able to rotate independently from the rotating shaft 28. The gear 48 meshes with a gear 52 fixed to a rotating shaft 50 rotatably supported by the frame 26. Thus, the rotating shaft 50
When the cup holder rotates, the sun gear 44 rotates independently of the rotating shaft 28 via the gears 52 and 48, and the cup holder rotates on its own axis via the planetary gear 42.

In this way, if the sun gear is rotated at a constant speed, the planetary gear 42 or cup holder 22
rotates at a constant speed even during the intermittent rotation of the indexing table 24, and when the indexing table 24 comes to rest, rotates at the same constant speed at that station. Note that when the direction and rotational speed of the intermittent rotation of the indexing table 24 are the same as the rotational direction and rotational speed of the sun gear 44, the planetary gear 42, that is, the cup holder 22, is not connected to the indexing table when the indexing table rotates. Although it does not rotate, it still rotates at a constant speed, and when the indexing table comes to rest, it rotates at the same constant speed at that station. In this way, no acceleration time is required for the rotation of the cup holder, making high-speed inspection possible.

In such a conveying device, it is necessary to rotate the cup holder at least one revolution while the indexing table is stationary. To this end, a method is usually used in which the rotation of the indexing table and the rotation of the cup holder have a certain relationship. One means for this is to drive the rotary shafts 28 and 50 from the same drive source through gears with appropriate gear ratios so that the cup holder always rotates once during the period when the indexing table is stationary. According to this method, the number of driving sources can be reduced, and the mutual operational relationship between the indexing table and the cup holder can be accurately determined by the gear ratio, which is convenient.

However, when considering adjustment of the dirt detection sensitivity of the detection processing device 12 and other maintenance, it is preferable to be able to rotate the cup holder at the same speed as during actual inspection while keeping the indexing table stationary.
Therefore, in the illustrated embodiment, the rotating shaft 28
is a cam index mechanism 53 for intermittent drive.
a, drive shaft 53b, variable reduction ratio reduction mechanism 53
The rotary shaft 50 is connected to an AC motor 53e via a belt 53d and a reduction gear 54a, and a continuous rotation DC motor 54b. However, with the same drive source, the rotating shaft 5
0 and the rotary shaft 28 through another gear and a clutch, so that only the cup holder can be continuously rotated by releasing the clutch.

A paper cup stacking cylinder 56 is arranged at the top of the supply station. This paper cup accumulation tube 5
A set of four cup feed screws 58 are provided at the bottom of the cup 6 and are rotated synchronously by a shaft 60, a sprocket 62 and a chain 64. Furthermore, one cup feeding screw shaft 60
is driven via sprocket 66, chain 68, sprocket 70 and shaft 72 by motor 74 which is driven in synchronization with the movement of the index table. Thus, the cup supplying screw 58 rotates synchronously with four rotations due to the operation of the motor 74, and the upper end flange portion (indicated by reference numeral 76 in FIG. 4) of the paper cup in the paper cup stacking tube 56 is transferred to the valley portion of the screw. While winding up the paper cups, each paper cup is separated one by one and fed onto a cup holder stopped at a feeding station.

In order to ensure that the paper cup fed to the cup holder by the cup feeding screw 58 is received and retained within the cup holder, in the illustrated embodiment, the paper cup is vacuum suctioned from the cup holder side. For this purpose, a hole 78 is formed in the bottom of the cup holder 22, and a hollow portion 50 is formed in the central shaft portion of the rotation shaft 34 so as to communicate with the hole 78.
Furthermore, holes 82 extend radially from the hollow portion 80.
is formed. An annular channel 84 surrounding the holes 82 is formed in the boss 30, and one end of a hose 86 is connected to the annular channel 84. The other end of the hose 86 is connected to holes 90 formed in an annular member 88 fixed to the rotating shaft 28 at equal angular intervals of 60 degrees. Another annular member 92 having an open hollow chamber formed on the side facing the hole 90 is attached to the rotating shaft 28 via a bearing 94 . This annular member 92
is fixed to the tip of a horizontal arm portion of an arm 96 fixed to the frame 26. As shown in FIG. 6, the hollow chamber of the annular member 92 includes a vacuum chamber 98 that extends in the circumferential direction to correspond to four stations: a supply station, a pushing station, an inspection station, and a spare station, and a defective product discharge station. It is divided into a first high pressure chamber 100 located at a position corresponding to the delivery station, and a second high pressure chamber 102 located at a position corresponding to the delivery station. The vacuum chamber 98 is connected to the hose 104
The first high pressure chamber 100 is connected to a compressed air source (not shown) via a hose 106 and a solenoid valve 108, and the second high pressure chamber 102 is connected to a source of compressed air (not shown) via a hose 106 and a solenoid valve 108. 109 and solenoid valve 110
is likewise connected to a source of compressed air (not shown) via.

Thus, the hollow portion 80 of the rotation shaft 34 is in communication with the annular channel 84 via the hole 82 even when the rotation shaft 34 is rotating, and the hollow portion 80 of the rotation shaft 34 is in communication with the annular channel 84 through the hole 82
A hole 90 in the annular member 88 to which the indexing table is connected communicates with the vacuum chamber 98 and either of the first and second high pressure chambers 100 and 102 according to the rotation of the indexing table. Therefore, when the cup holder is between the supply station and the reserve station,
Negative pressure is established in the cup holder through hole 78.
Therefore, at the supply station, paper cups fed from the cup supply screw 58 are drawn into the cup holder to ensure that they are received and retained at least until the reject station.

The paper cup thus placed in the cup holder is pushed into the cup holder by the pushing mechanism 112 at the next pushing station. This is for, when the paper cup is not properly held in close contact with the cup holder, to position the paper cup in the cup holder properly and bring it into close contact by pushing the paper cup. Therefore,
If the paper cup can be properly positioned and brought into close contact with the cup holder by vacuum suction, the pushing mechanism may be omitted. Conversely, the supply station may simply drop the paper cup without vacuum suction, and the push station may push the paper cup into place to hold it in place.

For example, as shown in FIG. 7, this pushing mechanism 112 has a triangular plate 118 fixed to a piston rod 116 of a piston cylinder device contained in a case 114, and a shaft 122 having a pushing disk 120 attached to its tip. Can be fixed and configured. The remaining two points of the triangular plate 118 are the case 114
A guide rod 126 fixed to the upper flange 124 of the
is slidably supported. Therefore, by operating the piston-cylinder device, the push-in disk moves up and down, and the paper cup in the cup holder can be reliably pushed to the bottom of the cup holder so that it can be properly held in close contact with the paper cup.

The paper cup that has passed through the push-in station is inspected at an inspection station, and further passes through a preliminary station to reach a defective product discharge station. If the inspection results indicate that the product is defective, the solenoid valve 108 is opened and compressed air is introduced into the bottom of the cup holder 22 through the first high pressure chamber 100, and as a result, the paper cup is ejected from the cup holder 22 and is not defective. The non-defective products are discharged through the discharge duct 128. On the other hand, if the paper cup is determined to be non-defective as a result of the inspection, it passes through the defective product discharge station and reaches the delivery station. Solenoid valve 1 energized every time the indexing table is idle
10 is then opened, compressed air is introduced into the bottom of the cup holder 22 via the second high pressure chamber 102, and the paper cup is delivered from the cup holder 22 through the delivery duct 130.

A surface detection device 1 is used to observe the inner surface of the paper cup while the paper cup positioned on the inspection station is rotating by the conveyance device described above.
There are 4. First, there are three typical surface detection methods as follows. That is, one uses an industrial television camera, one scans laser light and detects the reflected light with photosensitive means, and
Three of them use line sensors made of solid-state image sensors.

When using an industrial TV camera, it is possible to detect the entire object at once, and it can be said that it is advantageous in terms of cost because it allows the use of conventional imaging equipment.However, when using an imaging tube such as a vidicon, there is the problem of afterimages. arise.
In other words, if the paper cup to be inspected moves continuously, the image signal will include blur, and the resolution will substantially drop, making it impossible to detect fine stains. To solve this afterimage problem, you can use a light source that emits instantaneous light such as a flash xenon lamp to stop the image, or use an indexing mechanism in the conveyance device to intermittently move the paper cup. It is necessary to keep the object still at the inspection position and take the image. In this case, if the camera 132 takes an image from vertically above the center of the paper cup 20 as shown in FIG. 8A, the bottom will be imaged from the front, but the image of the side of the cup will be taken from a diagonal direction with a large inclination. I decided to do it,
The ability to detect dirt on the side surface, that is, the resolution, is significantly reduced.

This problem can be solved by taking an image from diagonally above the central axis of the cup 20, as shown in FIG. 8B, by increasing the angle of view with respect to the sides, and by increasing the ability to detect dirt on the sides. However, in this case, one camera cannot image the entire inner side of the cup.
Therefore, it is conceivable to take images from at least three cameras 2 diagonally above the central axis of the cup and spaced apart from each other at equal angles with respect to the central axis of the cup, as shown in FIG. 8C. With this camera arrangement, the detection ability can be improved, but since three cameras are used and three types of video signals are obtained, three of the same signal processing electrical systems are required. The overall configuration of the device becomes larger. Signal processing, especially for the edge part at the top of the cup.
It is expected that high performance will be required, such as signal processing for the side joint, signal processing for the joint between the bottom and sides, and improved concentration detection ability, making it inevitable that the circuit will become more complex and larger. Given this, it is not hard to predict that if three identical signal processing circuits are required as described above, the cost will be considerable. Furthermore, even if the camera cup is disposed obliquely to the center axis, the 8th D.
As shown in the figure, the inner surface portion 20A of the cup located at the center of the field of view captured by the camera and the side surface portions 20B on both sides of the cup become smaller in angle with respect to the optical axis of the camera toward the edge of the field of view, and the dirt detection ability is It is inevitable that there will be a significant decline in Therefore, the detection ability cannot be made constant for the entire cup.

In the method using a laser, for example, the flying spot method, the laser beam is narrowed down and the inside of the cup is scanned up and down while the cup rotates, scanning the entire inside of the cup and detecting dirt based on the level of reflected light. It is conceivable to detect and determine the presence and extent. This type of laser method requires a device to rotate the cup at the detection position, but one signal processing circuit is sufficient, and there is no uneven detection ability in the direction of rotation of the cup, so an industrial television camera is used. It's better if you do.

However, the method using a laser has the following drawbacks. First, mechanical vibration systems such as vibrating mirrors and rotating mirrors are required for optical scanning, but there are problems with their adjustment life. Second, since laser light is monochromatic, certain colored stains cannot be detected. Third
The main reason is that the laser light source itself has a relatively short lifetime. Fourth, in the case of the laser method, it is difficult to accurately determine the relationship between the detection signal and its detected position on the inner surface of the paper cup, making it difficult to process using the positional relationship between pixels. be.

Therefore, let's consider a line sensor consisting of a solid-state image sensor such as a CCD or BBD. If such a one-dimensional solid-state image sensor is arranged along the scanning direction of the laser beam as described above, (1) there will be no moving parts in the optical system, and (2) everything except the light source lamp can be constructed from solid-state elements. (3) The wavelength range of the light used for detection is wide, so detection of specific wavelengths is not impossible, (4) The positional relationship of each pixel is Since this is clear, dead zones such as seams of paper cups can be treated accurately, and the width of the dead zones can be reduced, among other advantages.

Therefore, a line sensor consisting of a solid-state image sensor is used as the surface detection device 14.

In order to inspect the entire inner surface of the paper cup while the paper cup rotates once, the line sensor 134 is used as shown in FIG. 9A.
A camera 138 including a camera 138 and an objective lens 136 is aimed from diagonally above the paper cup 20 located at the inspection station, at a point 140A at the bottom of the paper cup through which the rotation axis 140 of the paper cup passes, and at an upper end 142 of the paper cup on the side far from the camera. Place the camera at an angle and position that provides a bird's-eye view. Furthermore, as shown in FIG. 9B, the line sensor 134 in the camera 138 is
The line sensor 134 is positioned so that a plane 142 including the longitudinal axis of the paper cup and the rotation axis 140 of the paper cup is perpendicular to the side surface of the paper cup. With this arrangement, as described in connection with FIG. 8B, the line sensor 134 can image the entire inner surface of the paper cup due to the rotation of the cup, and can improve the ability to detect dirt on the side surface. As shown in FIG. 9A, if the angles formed by the surface perpendicular to the optical axis 146 of the camera and the side and bottom surfaces of the paper cup are γ and δ, respectively, then the resolution of the side and bottom surfaces is calculated as follows: It is inevitable that cos γ and cos δ will be lower than in a certain case. In this case, in order to equalize the resolution for the side and bottom surfaces of the paper cup, the camera is positioned so that γ=δ. However, when the side and bottom surfaces of the paper cup are scanned in the axial direction while the paper cup is rotating, the scanning line density on the bottom surface is higher than on the side surface. Therefore, in order to substantially equalize the ability to detect dirt on the side and bottom surfaces of a paper cup, it is preferable to make δ somewhat larger than γ.

However, in any case, the angle between the side surface and the bottom surface of the paper cup is only a right angle or a slightly larger angle. teeth,
It has to be around 45 degrees. Therefore, a reduction in resolution is inevitable compared to the case where the surface to be inspected is perpendicular to the optical axis 146 of the camera. Therefore, such a decrease in resolution is compensated for by increasing the number of elements in the line sensor, for example. To obtain the same resolution as when the surface to be inspected is perpendicular to the optical axis of the camera, the number of elements in the line sensor when the surface to be inspected is perpendicular to the optical axis of the camera must be at least √2 times. The number of elements is required.

If we consider the resolution of the line sensor here, the number of elements in the line sensor determines the resolution in the main scanning direction, and the rotation speed of the paper cup and the scanning period of the line sensor determine the resolution in the sub-scanning direction. In the example, a paper cup is rotated in 0.25 seconds, and a line sensor with 1024 elements is set at the main scanning frequency.
Driven at 5.5KHz, for ordinary paper cups, the speed ranges from 0.1mm/bit to 0.3mm/bit in both the main and sub-scanning directions.
A resolution of mm/bit was obtained. The frequency of the image information obtained at this time is about 6 MHz, and the image information is output at a high speed of about 167 ns/bit, which can be processed sufficiently.

However, since both the side and bottom surfaces of the paper cup to be inspected are inclined with respect to the optical axis of the camera, in order to form images of these surfaces on the line sensor without blurring, the method shown in Figure 9A is required. As shown, a depth of field D is required. The required depth of field D varies depending on the depth of the paper cup and the inclination of the camera's optical axis relative to the paper cup, but in any case, a considerable depth is required. Probably not. The depth of field D is determined by the distance from the camera's cup, the focal length of the lens used,
It varies depending on the aperture value, and in order to increase the depth of field D, it is necessary to use a lens with a long focal length and stop the aperture deeply. However, in order to obtain a sufficient depth of field by adjusting the depth of the aperture, the aperture must be narrowed down like a pinhole in a pinhole camera, which requires an extremely large amount of light, which is impractical. On the other hand, in the case of a normal aperture value, if an image of a paper cup of normal size is to be imaged from diagonally above, the required depth of field is ±40 mm. but,
Since the camera has to be positioned at a relatively close distance of less than 1 meter from the paper cup, it is not possible to use a lens with a very long focal length, for example several meters, which would enable such depth of field. Therefore, the problem of depth of field cannot be solved by aperture value and lens selection. On the other hand, in order to reduce the amount of light required, it is better to open the aperture as much as possible. Therefore, in order to be able to open the aperture and obtain a large depth of field with a small aperture value,
As shown in the figure, the light-receiving surface 150 of the line sensor is tilted in a direction opposite to the tilting direction, that is, tilting direction, of the inspection surface 148 of the paper cup relative to the lens 136.

Now, if the focal length of the lens 136 is f, then in order to make the magnification on the optical axis 146 M,
The intersection O between the optical axis 146 and the inspection surface 148 is located at f+f/M from the front principal point H of the lens. At this time, the imaging point O' on the optical axis is located f+(f×M) from the rear principal point H' of the lens. Therefore, the light receiving surface 1
50 is arranged so as to pass through the imaging point O'.
In this state, the inspection surface 148 and the lens 136
If the angle formed with the front principal surface of is β, then the light receiving surface 150
is adjusted so that the angle α between the light receiving surface 150 and the rear principal surface of the lens 136 satisfies tan α=Mtan β. Thereby, it is possible to form an image without being out of focus. At this time, the lens 13 on the inspection surface 148
A light receiving surface 15 on which an image of the point P farthest from 6 is formed.
The magnification at point P' on 0 is M/1 + M/f x PQ x sinβ, which is the magnification at point Q' on light receiving surface 150 where the image of point Q closest to lens 136 on inspection surface 148 is formed. is M/1-M/f×OQ×sinβ. In this way, the magnification varies somewhat depending on the location on the inspection surface, which causes distortion, but this does not pose any problem in stain inspection. The purpose of surface inspection is to determine the presence or absence of dirt or scratches on the surface, and it is not necessary to know the exact size of the dirt or scratches. Therefore, it is sufficient to detect the presence of dirt or scratches, and a slight difference in magnification does not matter. In addition,
To solve the problem of difference in magnification, the imaging plane 150
It is sufficient to increase the density of elements toward P'. Further, the inspection surface 148 may be aligned with either the side surface or the bottom surface of the paper cup, but it is preferable to align it with the longer one in the scanning direction. However, as a result, either the side surface or the bottom surface of the paper cup will come off the inspection surface 148 in FIG. 10, but this will hardly be a problem.

In this way, the inner surface of the paper cup can be detected without being out of focus. In order to enable the line sensor to similarly detect what the human eye perceives as dirt, it is preferable to make the spectral sensitivity spectrum of the sensor as close as possible to the visibility spectrum of the human eye. However, the spectral sensitivity spectrum of the sensor is determined by the photoelectric conversion element. Instead, the spectrum of the illumination light can be varied. Therefore, as a light source, the color temperature of halogen lamps, tungsten lamps, etc.
A light source of 2500°K to 3200°K is used, illuminated through an appropriate filter, and the proportion of light components with wavelengths that are lower than the human visual sensitivity spectrum within the spectral sensitivity spectrum of the sensor is calculated from the natural light spectrum. The ratio should be higher than that in

When detecting the inner surface of a paper cup as described above, there must be no unevenness in brightness on the detected inner surface of the paper cup. Therefore, it is preferable to illuminate from the same direction as the camera 138. On the other hand, it is necessary to detect the position of the seam of the paper cup in order to process the detection data, which will be described later. To do this, light is applied from a position away from the camera's optical axis so that the seam is shaded. For example, as shown in FIG. 11, the light is illuminated so that the sheet 154 located on the camera side is illuminated at the seam 152 of the paper cup with respect to the optical axis 146 of the camera. When the angle between the optical axis 146 and the illumination light at this time is θ, and the thickness of the sheet 154 is t, the width x of the shadow is expressed as t·tanθ. In order to ensure that the line sensor can sufficiently detect the shadow of the seam,
Preferably, the width of the shadow image of the seam on the line sensor is at least twice the width of the detection area of the line sensor. In this way, the line sensor can reliably detect the shadow of the seam.

The luminous intensity of the light source is determined from the brightness of the lens, the aperture, the sensitivity of the line sensor, the distance between the light source and the subject, the distance between the subject and the line sensor, the scanning interval of each photoelectric element of the line sensor, etc. In order for the line sensor to output a detection signal at the level required for image processing, if the detection time per cup is 0.25 seconds, the illuminance on the inside of the cup is
Approximately 250,000 to 350,000 Lutx is required. Furthermore, if the illumination is uneven, a state similar to so-called shading occurs, and detection accuracy in dark areas deteriorates. In particular, since the side surfaces and the bottom surface are not on the same plane, illumination from only the same direction causes a difference in brightness between the side surface and the bottom surface. For example, as in the case of FIG. 9A, the paper cup is illuminated obliquely from above so that the central axis of illumination is positioned parallel to the bisector of the angle formed by the side surface and the bottom surface. In any case,
Paper cups to be inspected come in various sizes, and some have different ratios of height and diameter, so the direction of illumination is determined depending on each cup.

Furthermore, the imaging range of the line sensor is vertically long.
Therefore, it is efficient to intensively illuminate the vertically elongated imaging range from a direction that can uniformly illuminate the area.

For example, as shown in FIG. 12A, light from a point light source 156 of several kilowatts is focused by a cylindrical convex lens 158 to illuminate an elliptical area 160. Alternatively, as shown in FIG. 12B, light from a point light source 156 is focused by a spherical convex lens 162 and then reflected by a cylindrical reflecting surface 164. Again, an elliptical area 160 is illuminated. Furthermore, light from a rod-shaped light source 166 such as a halogen lamp for a copying machine of several kilowatts is passed through a spherical convex lens 1.
The light is focused at 62 and the illumination surface is placed near the focal point of the lens. In this case as well, the elliptical area 160 can be illuminated.

In the illustrated embodiment, the method shown in FIG. 12B is adopted, and the process discriminating device 16 shown in FIG.
A point light source 156 and a spherical convex lens 162 are arranged inside, and the light from them is emitted outside through a hole 168.
A cylindrical reflective surface attached to the inclined surface 170 of the cover illuminates the paper cup located at the inspection station of the transport device 10. Thus, while the paper cup rotates on its axis at the inspection station, the surface inspection device 14, which is comprised of a line sensor, inspects the inner surface of the paper cup.

If it is preferable to identify the object to be inspected in color, it is sufficient to obtain R.C.B or Y.I.Q image signals by a known method, which would be easy for those skilled in the art.

The data on the inner surface of the paper cup detected in this way is processed by a processing determining device 16 as shown in the block diagram of FIG. 13, and the presence or absence of dirt is determined.

If we consider the inner surface of the paper cup, as described above, as shown in FIG. There are holes 180 etc. that are covered with metal foil, and in order to avoid misjudging them as dirt when processing is determined based on the detection data, it is necessary to perform dead zone processing on the detection data corresponding to those parts. . The width of the dead zone needs to be wide enough to allow for vibrations of the optical system, misalignment of the paper cup, eccentricity during rotation, etc., which cannot be completely eliminated. However, if data processing is performed with such a wide dead zone, even if there is dirt near the joint,
There is a high possibility that it will be included in the dead zone and will not be detected.

To consider this more specifically, FIG. 14B shows a dead zone when a simple dead zone process is performed on a paper cup as shown in FIG. 14A. The developed view of FIG. 14B shows a case where the center axis of the paper cup is slightly deviated from the axis of rotation, so that the edges 72 and seams 178 are somewhat wavy.

Even if the upper edge portion 172 in the field of view is clean, it is the boundary between the dark and bright areas, and there is a possibility of misjudgment. Additionally, the cup upper end flange 174
(A curled part or a part made flat by pressing a curled part) has many irregularities on the surface due to processing, and when stains are detected at the same level as for the side surface, these irregularities are incorrectly determined to be stains. Therefore, it is necessary to provide a dead zone 172D that includes the upper edge and the flange. Similarly, it is necessary to provide a relatively wide dead zone 178D at the joint 178 between the side and bottom portions. Furthermore, it is necessary to provide a dead zone for the bottom hole 180 as well. This bottom hole 180 is
Since the dead zone 180D is located at a random position with respect to the inspection start position, a dead zone 180D is provided that covers all parts where the hole 180 may appear.

If such dead zone processing is performed, a considerable portion of the detected data will be subjected to dead zone processing, and there is a high possibility that dirt will be overlooked. Furthermore, the side seam 17
It is also necessary to provide a dead zone 176D for the side seam 6 to perform dead zone treatment, but as described above, there has been no effective dead zone treatment method for side seams.
Therefore, automatic processing for inspecting the inner surface of paper cups has not been put to practical use until now.

The processing determination device 16 solves this problem and makes reliable stain inspection possible.

The processing determination device 16 performs dirt detection in both the main scanning direction (line sensor scanning direction) and the sub-scanning direction (rotation direction of the paper cup). Dead zone processing for directional objects such as top edges, flanges, side seams, side bottom seams, etc. is performed when contamination is detected only in either the main scanning direction or the sub-scanning direction. In stain detection in one scanning direction, dead zone processing is not performed so that no dead zone exists. Furthermore, since stain detection is performed in both the main scanning direction and the sub-scanning direction, dead zone processing can also be performed on the side seams. Regarding the hole at the bottom, focusing on the fact that the positional relationship with the side seam is almost constant, the seam is detected and only the part of the bottom that is at a certain position with the seam is masked. It is preferable not to perform dead zone processing even on the most sensitive parts.

If the central axis of the paper cup is eccentric from the rotation axis, the address of the image signal indicating the upper edge of the paper cup (for example, the address number counted from the edge of the line sensor element) changes every main scan. Therefore, when performing dead zone processing on the upper edge, the dead zone must be widened based on the address of the image signal. Therefore, in order to minimize the dead zone, the part that changes from dark to bright after the start of each scan is determined to be the top edge part, and based on this, the starting point of the inspection target area is determined, and the inspection start address is set as the top edge part. change according to. This results in
Minimize the dead zone for the top edge.

In this way, an inspection area is set within the scanning section, and stains are detected only in that area. In this way, even if the central axis of the paper cup is eccentric with respect to the rotational axis, the position of the upper edge within the inspection area is always constant, so the dead zone can be kept narrow.

The determination processing device 16 that performs the processing described above includes a preprocessing section 200 and a data processing section 202, as shown in FIG. A display device 204 is connected to the data processing unit 202, and further,
A distribution control device 206 attached to the transport device 10 is connected. When the data processing unit 202 outputs a defective signal and the paper cup determined to be defective is sent to the defective product discharging station of the conveyance device 10, the distribution control device 206 controls the valve 10.
8 and discharge duct 12 with compressed air.
Discharge through 8. And the distribution control device 20
6, when the cup holder is sent out and comes to the station, regardless of whether there is a paper cup or not,
Valve 110 is opened to direct compressed air from the bottom of the cup holder at its delivery station. At that time, if there is a paper cup that passes the inspection, it is
It is sent out through delivery duct 130.

A surface detection device 14 equipped with a line sensor composed of N pieces, for example, 1024 solid-state image sensors.
are read out in series in synchronization with the clock signal from the clock circuit 208, amplified by the preamplifier 210, and input to the preprocessing section 200. This preprocessing section 200 includes a waveform shaping circuit 212, an A/D conversion circuit 214, and an edge enhancement/smoothing circuit 216.

Analog signals for N pixels when one scan is performed with a line sensor are caused by unevenness of the surface to be inspected, non-uniform illumination, etc.
Due to differences in optical path length from the surface to be inspected to each element of the line sensor, distortions such as shading, so-called parabolic distortion, etc., as shown in FIG. 15A occur. Since these distortions only change slowly over one scan, the waveform shaping circuit 212 tracks the average envelope and corrects it as shown in FIG. 15B.

The A/D conversion circuit 214 converts each distortion-corrected analog pixel signal into a 6-bit to 8-bit digital pixel signal per pixel according to its level, as shown in FIG. 15B. At this time, the level of the analog pixel signal corresponding to the background black or pure white, which does not appear in the image information of the subject, is discarded, and as shown in Figure 16, the analog pixel signal level that appears in the image information of the subject, that is, the intermediate It is efficient to digitize so that all gradations are assigned only to the signal level portion corresponding to the tone. 6 per pixel
Using bits, it can be divided into 64 gradations.

The contour enhancement/smoothing circuit 216 selectively performs either contour enhancement or smoothing.

When a halftone stain D as shown in FIG. 17A is scanned along the line S, the pixel signal level is 17th.
As shown in Figure B, the boundary is unclear.

Contour enhancement makes the range of dirt information clear by sharpening the density change near the boundary where the contrast is unclear, as shown in FIG. 17C, so that the dirt information can be extracted easily and completely. It is an object. This treatment enhances the contrast of small, pale stains and makes them easier to extract. According to the theory of contour enhancement, the image f(x,
If we find the Laplacian ▽ ² f (x, y) = ∂ ² f (x, y) / ∂x ² + ∂ ² f (x, y) / ∂y ² ...(1) for is known to give a function with enhanced contours. but,
In this embodiment, the difference between the information of a pixel to be subjected to contour enhancement processing and the information of surrounding pixels adjacent thereto is used as contour information. In other words, for the center pixel E of 3 pixels in 3 rows as shown in FIG. When pixel information A, I, C, and G in the 45-degree direction is also taken into account, one-half of the sum of eight pixels is subtracted from 4E, and this value is used as contour information. Image information with enhanced contours can be obtained by adding this contour information to E. In this way, an effect is produced in which E becomes increasingly white in white areas and increasingly black in black areas, and the outline becomes more prominent. At this time, a weight may be added by multiplying E by a coefficient K. Image information at this time can be obtained by adding contour information to KE and dividing this by K.

Smoothing is performed by removing paper surface noise and instantaneous noise generated in the photoelectric conversion system and other systems as shown in Fig. 19A, as shown in Fig. 19B, to avoid false detection when extracting dirt information. It is something. In this case, as in the method of contour enhancement, the level of the central pixel information E of the information of three columns of three pixels is determined by taking the arithmetic average of the information of the surrounding four or eight pixels.
Alternatively, considering the weight K for E, 1/2 of 4 pixels or 8 pixels may be added to KE and divided by K+4.

Such contour enhancement and smoothing are used appropriately depending on the surface condition of the article to be inspected, so as to obtain data that is easy to process in the next processing circuit.
That is, when there is light dirt on the surface that does not generate instantaneous noise, such as when inspecting the inner surface of a paper cup, only outline enhancement is sufficient. However, for articles whose surfaces are stained with high-contrast stains and which often cause instantaneous noise, only smoothing is required. Note that when there is noise with a small amplitude, such as paper noise, and the contrast of dirt is not sharp, it is possible to use edge enhancement and smoothing together.

The circuit configuration and operation of the edge enhancement/smoothing circuit 216 will be explained below with reference to the block diagram of FIG. Since the number of pixels for one scan of the input information f(t) is N, the (N-1) dot shift register 218 and the 1-dot shift register 220, 2 constitute a total of (N+1) dot shift registers.
From the 22nd N-th shift register 220,
It is connected to the input of the shift register 224 of the shift registers 224, 226, and 228 that constitute the same (N+1) dot shift register, and similarly, the output of the N-th dot shift register 226 is connected to the input of the shift register 224 of the shift register 224, 226, and 228 that constitute the same (N+1) dot shift register.
1) Shift register 230 among shift registers
Connect to the input of Outputs A and 1 are output from the (N-1)th dot, Nth dot, and (N+1) dot of these three (N+1) dot shift registers, respectively.
Obtain B・C, D・E・F, G・H・I. With this configuration, it is possible to obtain output information for three pixels of three adjacent scanning lines from the latest part of input information f(t) that is continuously sent. Since the input information is sent one after another, each pixel is sequentially I, H, G, F, E, D, C, B, A.
is output in the section. 3 obtained in this way
Image information for three columns of pixels is sent to adder circuits 234 and 236. The adder circuit 234 calculates g ₁ =B+H+D+F...(2) for the four pixels on the top, bottom, left and right sides, and calculates g 1 =B+H+D+F...(2) for the four pixels in the 45° direction.
36 calculates g ₂ =A+I+C+G...(3). When considering the surrounding 8 pixels, g ₁ and g ₂
are added by addition circuit 238. but,
When considering only four pixels, the peripheral pixel number selection signal becomes low level (hereinafter referred to as L), turns off the AND circuit 240, and cuts off _g2 , so that the output of the adder circuit 238 is only _g1 . The output (g ₁ +g ₂ ) of the adder circuit 238 is not only applied to the selection circuit 242 as is, but also divided by a constant 2 by the division circuit 224 and then added to the selection circuit 242 . When the peripheral pixel number selection signal is set to L, g ₁ and g ₁ /2 are selected by the selection circuit 34.
Among them, only g ₁ is selected and its output g becomes g=g ₁ =(B+H+D+F) . . . (4). When the peripheral pixel number selection signal is set to high level (hereinafter referred to as H), the AND gate 240 is opened, so that (g ₁ +g ₂ ) and (g ₁ +g ₂ )/2 are connected to the selection circuit 2.
42, of which only (g ₁ + g ₂ )/2 is selected, and g is g=(g ₁ +g ₂ )/2 = {(B+H+D+F)+(A+I+C+
G)}/2 ...(5). On the other hand, the pixel information E and the constant 4 are input to the multiplication circuit 246, 4E is calculated, and this 4E and g are added to the subtraction circuit 248, and the contour information △E △E=4E−g...(6) is obtained. On the other hand, the pixel information E and the weighting coefficient K are added to the multiplication circuit 250 to obtain KE, and this KE and ΔE are added to the addition circuit 252 to obtain (KE+ΔE). This (KE＋△E)
Pixel information for contour enhancement when added to the division circuit 254, divided by the weighting coefficient K, and given a weight of K F(t)=1/K(KE+ΔE)=(K+4)E−g/K ...(7) is obtained. This F(t) is output from the selector 256 when the selection input of the selector 256 is set to H. The smoothing operation is performed by adding KE and g produced by the multiplication circuit 250 to the addition circuit 258 (KE+
g) and add this (KE+g) to the addition circuit 260.
(K+4) obtained by is added to the division circuit 262 to obtain smoothed pixel information F(t)=KE+g/K+4 (8) when weighted by K. This F(t) is output when the selection input of the selector 256 is set to L. The selection of 4 pixels and 8 pixels, smoothing, emphasis, and weighting may be made manually or automatically depending on the surface condition of the article.

The digital pixel signal of 6 to 8 bits per pixel, which has been preprocessed as described above, is sent to the data processing section 202.

The data processing unit 202 includes dirt information detection circuits 264 and 266 that detect information about the article to be inspected, a memory 268 that stores this dirt information, and a joint, mark, character, etc. on the surface to be inspected that is misidentified as a scratch or dirt. a mask pattern circuit 270 that creates a mask pattern for removing the portion to be detected, and reference coordinate setting circuits 272 and 27 that create reference coordinates for determining the position of the mask pattern and dividing the detection range.
4, a comprehensive determination circuit 276 that determines whether the obtained information is correct or not, and a mask verification circuit 294 that performs verification between the mask pattern and dirt information. The dirt information detection circuit and the reference coordinate setting circuit are provided for the main scanning direction and the sub-scanning direction, respectively.

In the preprocessing unit 200, the waveform shaping circuit 212 corrects the waveform distortion, and the contour enhancement/smoothing circuit 216 smooths the noise amplitude, but the noise cannot be completely removed, and residual waveform distortion and The existence of noise is unavoidable. Therefore, the dirt information detection circuits 264 and 266 not only effectively remove the waveform distortion and noise remaining in the dirt information extraction circuits 278 and 280, but also reliably extract thin dirt buried in the noise. Furthermore, error information correction circuit 2
82 and 284 remove isolated points such as residual noise and small dirt within an allowable range, phase adjustment is performed to the circuit with the most phase delay using phase correction circuits 286 and 288, and determination circuit 29
Slightly large stains within the allowable range are removed at 0.292, and the quality of the article is determined by comparing it with the mask pattern.

The dirt information extraction circuits 278 and 280 calculate a dynamic average value and set an appropriate threshold to reduce the effects of distortion and noise, and also make it possible to clearly detect dirt with low contrast. It is something. Here, the dynamic average value is
For density information of a certain pixel, it refers to the interval average of a one-dimensional or two-dimensional area in the vicinity of the density information. If we consider a one-dimensional case and assume a pixel range of n before and after the information a _k shown in Figure 21A, the dynamic average value A _k for the information a _k is expressed by the following equation, which can be expressed as It is indicated by A _k in FIG. 21A.

A _k = 1/2n _o 〓 ^{a i=-n+1} K+i ...(9) This dynamic average value can be regarded as representing waveform distortion, so the difference d _k from the original information is , d _k = a _k −A _k (10) as shown in FIG. 21B, and can be regarded as a signal from which waveform distortion has been removed. The thus obtained d _k is first sliced at a sufficiently deep threshold T _HI as shown in FIG. 22A, and a peak S _I with a large amplitude is detected as shown in FIG. 22B. This corresponds to heavy dirt. On the other hand, thin dirt D in a wide range as shown in Fig. 23A has a low peak value, so T _HI
It is not sliced, but the levels are skewed in the same direction. Therefore, for d _k , the dynamic average value D _k = 1 _/ 2d _d 〓 ^{d i=-d+1} K+ _i . For example, as shown in Figure 23C.
An interval A′ is obtained. This A' is smaller than the actual dirt range, so it is enlarged to the 23rd area.
Find area A as shown in diagram D. If this range A is set as an inspection section and _dk is sliced at a sufficiently shallow threshold T _H3 as shown in FIG. 23E, a thin stain S ₂ can be detected as shown in FIG. 23F. At this time, the noise N is not detected because it is not in the inspection section A. Therefore, only light dirt can be detected.

Threshold T _H1 used in the above processing,
T _H2 and T _H3 determine the density of dirt to be detected as dirt, and should be set to appropriate values depending on the nature of the surface of the article and the dirt standard. is preferred.

The dirt information extraction circuits 278 and 280 perform the detection data processing as described above, and furthermore, since what seems to be dirt is detected, dirt information for each pixel is converted into binary data to facilitate subsequent processing. Convert and output.

2 output from the dirt extraction circuits 278 and 280
Although a considerable amount of noise has already been removed from the digitized dirt information, there are still isolated noises 294 and chips 296 as shown in FIG. There are also stains and chips that cannot be seen.

The error information correction circuits 282 and 284 are for removing the above-mentioned noise, chipping, etc. Isolated points can be removed by theoretical processing. For example, the value of the dirt information of the pixel at the coordinate point (I, J) is F
(I, J), and find G(I, J) using the following formula.

G(I, J) = (I-1, J)・(I++1,
J)・(I, J−1)・(I, J+i) ……(12) However, (I, J) is the complement of F(I, J).

When black is 1 and white is 0, if G (I, J) = 1 and F (I, J) = 1, then point (I, J) is considered to be an isolated "spot" and is removed. . Similarly, "chips" can also be removed. Depending on the surface of the article to be inspected, either the above-mentioned "stains" or "chips" can be weighted and detected. Dirt or chips larger than isolated points are determined and removed by a mesh filter. As shown in FIGS. 25A and 25B, the mesh filter determines the size of a pixel f (i, j) by determining the continuity between adjacent pixels, and detects pixels that are smaller than a predetermined size. This is considered to be non-contamination and removed. The main scanning direction filter shown in FIG. 25A and the sub-scanning direction filter shown in FIG. , a two-dimensional investigation is performed, but the main scanning direction filter is long in the main scanning direction.
The sub-scanning direction filter is different in that it investigates continuity over a long period in the sub-scanning direction. With this mesh filter, it is preferable to be able to set the size of a stain or chip in several stages, since the size of a stain or chip that is determined to be non-contamination varies depending on the nature of the article and the standard of the stain.

The phase correction circuits 286 and 288 include a dirt information detection circuit, a mask pattern circuit 270, a reference coordinate,
Of the setting circuits 272 and 274, the sub-scanning direction reference coordinate setting circuit 272, which is usually the most delayed in phase, is matched in phase, and the phases of all systems are matched for subsequent signal processing.

The determination circuits 290 and 292 detect stains larger than the stains removed by the error information correction circuits 282 and 284, remove smaller non-standard stains, and output stain data. For example, the continuity between each pixel is checked for 5 pixels in the main scanning direction and 3 pixels in the direction perpendicular thereto, for a total of 15 pixels. For example, 15
When all pixels show dirt, it is detected as dirt. However, the range and number of pixels to be sampled to determine dirt, and the number of pixels exhibiting dirt that serve as a reference for determining dirt, vary depending on the object to be inspected and detection accuracy. Until the mask pattern data is sent from the reference memory, these determination circuits compress dirt data from which dirt other than dirt that can be determined to be dirt has been removed by the dirt information compression circuit 298 and store it in the dirt information memory 268. Store in. This compression is to save memory capacity. When the sub-scanning direction reference coordinate setting circuit 272 detects the reference axis, the reference memory 300 outputs mask pattern data to the determination circuits 290 and 292. Upon receiving mask pattern data from the reference memory 300,
The determination circuits 290 and 292 compare the stain information with the mask to detect whether or not there is stain exceeding the above-mentioned standard in the unmasked portion.
Then, the dirt detection result is sent to the comprehensive judgment circuit 276.
sent to. The comprehensive judgment circuit 276 judges whether there is dirt or not, or judges whether the amount of dirt is greater than a reference amount, determines pass/fail, and outputs a pass/fail judgment signal to the distribution control device 206.

As described above, the dirt information detection circuits 264 and 26
6 and the attached judgment circuits 290 and 292 function, but the sub-scanning direction dirt information detection circuit 266
A detection axis conversion circuit 302 is provided as a stage.

As shown in FIG. 26, this detection axis conversion circuit 302 has a register configured by connecting n N-dot shift registers 304 in series, since the number of pixels in one scan in the main scanning direction is N. are doing. Then, the dynamic average of the outputs of the n shift registers 304 is taken and output as the dynamic average value of the output pixels of the central shift register of the n shift registers 304. Since the shift register 304 stores pixels for one scan in the main scanning direction, the outputs of the n shift registers 304 are
pixels. Since pixel signals are sequentially input from the first shift register, shifted and updated, pixel signals obtained by dynamically averaging n pixel signals in the sub-scanning direction can be obtained in order in the main-scanning direction. . The pixel signals obtained by averaging the moving image in the sub-scanning direction are output to the dirt information extraction circuit 280. Therefore, instead of orthogonally converting the coordinate axes, this detection axis conversion circuit takes a dynamic average in the sub-scanning direction and outputs data in the main scanning direction.

The reference coordinate setting circuits 272 and 274 determine where the position of the mask pattern corresponds to the detected information when dividing the inspection surface into several parts or when separating and comparing the part containing the mask pattern from other parts. It provides a reference axis when it is not specified. This necessity differs depending on the shape of the article, the position and number of mask patterns, the scanning method, etc., but it applies to articles that do not require a mask at all, and articles where the masked part is always in a fixed position even if it is necessary. In contrast, there is little need for this. In order to detect such coordinate axes, some reference line that can be reliably detected in the information of the inspection item, such as the edge of the item, fold, cut, uneven line, seam, printed line, etc., and One parallel to the scanning direction can be used. The obtained coordinate information in the main scanning direction or the sub-scanning direction is distributed to a determination circuit of a dirt information detection circuit, a dirt information memory, a reference memory, etc., depending on the purpose. Detection of self-referenced coordinate axes requires that the line used as the coordinate axis has sufficient contrast with other lines, is thick enough to cover small and large bends and tilts with respect to the main scanning direction or sub-scanning direction, and can be clearly identified. In some cases, a simple slicing circuit can be used. When there is a lot of background or other distortion, it is sufficient to take the dynamic average value explained in the dirt information extraction circuit and detect the difference value from the input information. To detect the coordinate axis parallel to the main scanning direction, that is, the reference axis in the sub-scanning direction, it is sufficient to input the preprocessed image information as is. The output of the detection axis conversion circuit 302 may be input. Even lines that are extremely thin or have low contrast, such as seams, can be detected using pattern projection technology.

For example, the reference coordinate setting circuit 274 in the main scanning direction detects, as described above, the place where the dark changes to light detected immediately after the start of each scan in the main scanning direction as the upper edge, and sets this as a point on the reference line. can be used. Information on this reference point is determined by the judgment circuit 2.
90, 292, reference memory 300, and dirt information memory 268.

FIG. 27 shows the reference coordinate setting circuit 2 in the sub-scanning direction.
72 shows a schematic configuration example of a seam detection circuit that can be used as a seam detection circuit. When the side surface of the paper cup shown in FIG. 14A is unfolded, it becomes as shown in FIG. 28A.
When scanning along the seam S, the level of the pixel signal r for one scan when scanning the seam S portion becomes somewhat lower overall as shown in FIG. 28B. However, when the dirt D is scanned, the level of the pixel signal for one scan is reduced only by the dirt D portion. Therefore, the projection pattern circuit 306 of the seam detection circuit calculates the sum of pixel signals for one scan as shown in FIG. 28C. By doing this, the level of the pixel signal for one scan of the seam area is lower than the sum of the pixel signals for one scan other than the seam area, even if there is black dirt on the scan line of the area other than the seam area. It becomes very low and can be distinguished.

The sum signal for each scanning line obtained in this way is input to the reference line emphasis circuit 308. This reference line enhancement circuit slices the input signal at a slice level TH ₄ as shown in FIG. 28C to enhance the contrast. The reference line detection circuit 310 that receives the signal f _v thus obtained calculates the dynamic average value A _v of the signal, and calculates the difference r _v r _v = f _v − A _v (12). , r _v becomes negative and its absolute value is equal to or larger than the reference value (threshold value V _T ),
Determine it as the reference line. And address circuit 312
outputs the address of the reference line in the sub-scanning direction.

FIG. 29 shows a specific configuration example of the reference line detection circuit, and will be described by taking as an example a case where the side seam of a paper tip is detected so that it can be used as the sub-scanning direction reference coordinate setting circuit 272.

The input information is applied to adder 314, its output is sent sequentially to latches 316 and 318, and the output of latch 318 is input to adder 314. Thus, the input information is added by adder 314 and latches 316 and 318, but since latches 316 and 318 are reset every main scan, the total pixel information for each scan line is added by latch 316. can get. That aggregate signal is then
A constant number is subtracted by a subtracter 320 to enhance the contrast and obtain the aforementioned data _fv . this
In addition to the 2n dot shift register 322, the adder 324 calculates the sum of each dot, and the divider 3
By dividing 2n by 26, the dynamic average value A _v of 2n pixels can be obtained. Next, as shown in equation (12), from the median value f _v of the shift register 322, the subtracter 3
Subtract A _v by 28 and find the difference r _v . Since r _v is negative at the reference line, that is, the position of the seam, the adder 330 stores this r _v and the threshold value.
V _T is added, and when the sum (r _v +V _T )≦0, it is determined that the seam is the desired seam.

The inner surface inspection of the paper cup is performed by rotating it on its axis.
Since it is rotated beyond the circumference, a second seam may be detected. When the first seam is detected, the 0 terminal of the counter 332 becomes H, the AND gate 334 opens, and a seam detection signal is output from the seam 1 output line. When the second seam is detected, the 0 terminal of the counter 332 becomes L and the 1 terminal becomes H, so the AND gate 336 opens and a seam detection signal is output from the seam 2 output line.

The mask pattern circuit 270 includes a circuit 338 for extracting a mask pattern and a circuit 3 for performing phase correction.
40 and a circuit 34 for expanding the range of the mask pattern.
2, and a circuit 3 that compresses the entire mask pattern information.
44 and a reference memory 300 that stores information on the compressed mask pattern.The mask pattern consists of a reference memory 300 that stores information on the compressed mask pattern, and the mask pattern is a part of the object to be inspected that is free from scratches or dirt and is to be masked before starting the normal inspection. This is created from the information captured by painting it black or making holes to add strong contrast. In this way, the obtained information has a sufficient level difference between black and white, so the mask pattern extraction circuit 338 can be configured by a simple slice circuit. Phase correction circuit 340
This is necessary to match the phase with data processed by other circuits, as described in the dirt information detection circuit. The mask pattern is often located on a limited portion of the surface of the article. At times like this,
The reference memory 300 only needs to be used for that part. Further, when there are several mask patterns, a reference memory can be provided for each pattern. Furthermore, when the mask pattern covers the entire screen, the mask pattern information can be compressed to save memory. The mask pattern information compression circuit 344 is provided for this purpose.

Contamination information includes areas that should be masked, so these areas must be masked reliably, but due to reasons such as inconsistency in inspected items and rotational deviation, it is difficult to match the mask pattern to the mask in the contamination information. The parts that should be done do not necessarily match. In this case, the information on the portion to be masked may be mistaken as dirt information, so it is preferable to expand the range of the mask pattern to some extent in advance to ensure masking. The mask pattern range enlarging circuit is provided for this purpose.

As will be described later, after the reference coordinate axes in the sub-scanning direction are detected, the mask matching circuit 294 performs
The mask pattern is compared with the data stored in the dirt information memory 268 from the start of scanning until the detection of the coordinate axes. Alternatively, the amount of dirt is detected and the result is sent to the comprehensive judgment circuit.

Next, the directionality of dirt and the difficulty of detecting it will be explained, and then, in connection with this, a mask for the seam in the main scanning direction and the sub-scanning direction and a method for detecting dirt in the vicinity of the seam will be explained. When the shape of the dirt D is elongated at right angles to the scanning direction S, as shown in FIG. become more susceptible to On the other hand, when the shape of the dirt D is elongated along the scanning direction S,
Even if the dynamic average value is taken, no clear contrast will be produced and it will be difficult to detect. It is difficult to detect stains having such a shape without using the pattern projection method described above. Therefore, since the edges 172 and the seams 178 between the sides and the bottom of the paper cup are detected by scanning in the main scanning direction, the contamination detection circuit in the main scanning direction masks the seams for detection. conduct. For the same reason, the seam 176 on the side surface in the main scanning direction must be detected by being masked by a dirt detection circuit in the sub-scanning direction.
On the other hand, the seam contrast is small and thin, so
Depending on the longitudinal scan, it is more difficult to detect than the thin dirt described above. The upper edge 172 of the cup is also
During scanning in the main scanning direction, sufficient illumination is applied to enhance the contrast from dark to bright areas, so the contrast inside the edges is small and, like seams, is harder to detect than thin stains. Therefore, the threshold described in the stain detection method is adjusted so that although light stains can be detected, the contrast of edge portions and seams are not detected.
In this way, the dirt on the edge 172 and the seam 178 between the side surface and the bottom surface that are masked in the detection of dirt in the main scanning direction, and the reference line portion 176 on the side surface that is masked in the detection of dirt in the sub-scanning direction, can be removed in the sub-scanning direction. Also, no masking is performed in the detection of dirt in the main scanning direction. This makes it possible to effectively detect dirt in that area. On the other hand, the upper bent portion 176A of the side seam needs to be masked in main scanning and sub-scanning dirt detection.

FIG. 31 is a developed view obtained by scanning the paper cup shown in FIG. 14A along the side seam while rotating it one or more revolutions, and FIG. 32 illustrates the related operations between each circuit. 13, and the main circuit operations will be explained with reference to these drawings and FIG. 13.

When creating a mask pattern, the dirt information detection circuits 264 and 266 are not used. First, a paper cup coated with contrast is attached to the cup holder of the testing station and rotated. Then, the mask pattern generation terminal M ₀ of the mask pattern circuit 270 is set to high level, the mode selection gates 350 and 352 are set to the M ₀ mode by selects 1 and 2, respectively, and the address signal CN ₀ from the counter 362 is reset. The data will be written to the arrangement memories 300A and 300B.

Thus, scanning is performed regardless of the position of the side seam of the paper cup. This starting point is defined as scanning line a in FIG. 31. Then, as the scanning progresses and reaches the scanning line b running on the first side seam 176,
A high-level seam detection signal is output to the seam 1 output line of the seam detection circuit shown in FIG. 29, which serves as the sub-scanning direction reference coordinate setting circuit 272. As a result, AND gate 354 is opened, flip-flop 356 is set, and one input of AND gate 360 is held high via OR gate 358. As a result, a main scanning clock that generates one pulse per main scanning is applied to the count-up input UP of the up-down counter 362 via the AND gate 360. Thus,
This counter 362 counts the address of each main scan when viewed in the sub-scanning direction with the side seam 176 as a reference, and the address count is stored as a sub-scanning direction address in the reference memories 300A, 300B via mode selection gates 350, 352. Output a signal. A main scanning direction address signal for defining the address in the main scanning direction of the pixel signal obtained in each main scanning is also supplied to these reference memories via a line 364. At this time, the reference memories 300A and 300B are R/W
The line has been put into write mode.

On the other hand, pattern information obtained by detecting the mask pattern is transmitted from the mask pattern extraction circuit 338 to the shift register 3 via the phase correction circuit 340.
66. In this embodiment, the mask pattern information includes a high level signal in which white represents 1;
Black is a low level signal representing 0. The shift register 366 is constructed by connecting n N-bit shift registers for one main scan in series, and connecting the output of each shift register to an AND gate 368.

By doing this, the black range in the sub-scanning direction, that is, the mask, is expanded in the sub-scanning direction, since it will not turn on unless all n pixels in the sub-scanning direction become white. This output is applied to an m-bit shift register 370, and the output of each stage is applied to an AND gate 372. As a result, the mask is similarly enlarged in the main scanning direction. Therefore, shift registers 366, 370 and AND gates 368, 372
The mask is enlarged two-dimensionally. These constitute the mask pattern range enlarging circuit 342 in FIG. Information that has undergone this treatment is sent to reference memories 300A and 300B. Since both memories are in write mode, writing is performed. During this writing, information is compressed to save memory capacity. Compression is performed by reducing the address frequency to 1/m of the image frequency. If this is done, one piece of input information will be written to the memory at a rate of one piece for every m pieces of input information, so the data will be compressed to 1/m pieces. In the paper cup embodiment, one quarter is suitable. The reference memory 300A stores the mask pattern of the upper bent portion 176A of the side seam, and the reference memory 300B stores the mask pattern of the hole 180 on the bottom side of the side bottom seam 178.

As the writing progresses, a predetermined number of main scans are completed from the detection of the side seam 176, and the bent portion 17 of the side seam is detected.
When reaching scanning line C, which is a little past the upper end of 6A, the chip select input of reference memory 300A is activated.
A write stop signal is input to CS ₁ , and writing to the reference memory 300A is stopped. When the second side seam is detected, the seam detection circuit shown in FIG. 29, which constitutes the sub-scanning direction reference coordinate setting circuit 272, outputs a high-level seam detection signal to the seam 2 output line. the result,
AND gate 374 opens and counter 3 at that time
62, ie, the address indicating the length of the screen for one rotation of the paper cup, is written into latch 376. The writing progresses further, and when the predetermined length is further written from the second seam detection and reaches the scanning line f, a write stop signal is input to the chip select input CS ₂ of the reference memory 300B, and the write stop signal is input to the chip select input CS 2 of the reference memory 300B. Writing is stopped. The mask pattern is now stored in the reference memories 300A and 300B.

Next, an overview of paper cup dirt information detection will be explained. Generally, when detecting dirt information,
Real-time processing as much as possible, that is, without storing detected data in buffer memory,
It is absolutely necessary to perform predetermined processing and output immediately in order to perform high-speed calculations. Referring to FIG. 31, since there is no part to be masked at the side Y where there is a seam 176 in the main scanning direction, real-time processing is possible. Part X where the seam 176A is bent at the top on the side
However, as will be described later, the contamination information detection circuit is delayed by the time required to scan the bent portion of the side seam from the side seam 176 in the main scanning direction, which is the reference axis in the sub-scanning direction. By starting, the scanning of the portion to be masked can be performed without fail after the reference line is detected, so real-time processing is possible. Further, the memory at this time is only needed at the bent portion of the seam.
Since the hole 180 in the bottom part Z is at a constant position with respect to the reference line, real-time processing is possible after the reference line is detected, but from the start of scanning until the reference line is detected, the dirt information memory is memory 2
68, and after scanning is completed, the mask verification circuit 2
At step 94, the mask pattern of the hole is compared with the reference memory 300B in which it is recorded, mask processing is performed, and a determination is made. The capacity of the dirt information memory 268 is sufficient for one rotation if scanning is started immediately after the reference line.

Seam 178 between top edge 172 and bottom side surface
Since the size of the cup is accurately determined by each type of cup, the main scanning direction dirt information detection circuit 264 performs masking based on the signal from the main scanning direction reference coordinate setting circuit 274. At this time,
The masking width may be set to a value that is safe for the dimensional accuracy of the paper cup.

The upper bent part of the side seam can be masked in real time by reading out the mask pattern in the reference memory 300A and collating it after the reference line has been detected, but scanning is started only at this bent part. At that time, the reference line is not detected until almost one revolution. Therefore, if mask processing is performed after that, it is necessary to perform one more round until the processing is completed, and it is necessary to scan two screens in total. When scanning is performed by rotating the cup, it is possible to scan two screens, but this increases the processing time. It is also possible to prepare a memory for storing information for one screen and process the information in this memory after one screen is scanned. In this case, there is an advantage that only one screen needs to be scanned, but there is a problem that a memory for one screen is required for this purpose. The circuit shown in FIG. 32 skillfully deals with this problem, and is configured so that it is sufficient to scan almost one screen and no memory is required to store information for one screen. That is, the start of the dirt information detection operation is delayed from the start of the seam detection scan by at least the time required from the detection of the vertical portion of the side seam to the end of scanning of the upper end of the bent portion of the side seam. By doing this, even if seam detection scanning starts from the top of the side seam, dirt information detection will start after passing the bend of the top seam, so this bend will always be detected by the reference line. will be detected later. The bent portion can be checked against the reference memory in real time after the reference line is detected, as will be described later. Thus, the sides are
By taking the above measures, it is possible to process the detected dirt information in real time, no matter where the scanning starts with respect to the reference line.

On the bottom surface, the mask pattern of the holes 180 is spread out in locations determined by the type, so the above method cannot be adopted. The above location is drilled at a fixed location based on the side seam, so if this reference line is detected, verification can be done in real time, but in order to do so, it is necessary to scan an additional screen after detecting the reference line. There is. In the present application, even when performing mask pattern matching on the bottom surface, only one screen is sufficient for detecting information, and the processing speed is made as fast as possible. That is, at the same time as scanning starts, the bending part X at the top end and the side surface Y are detected in real time, and information on the size of the dirt on the bottom surface Z is compressed and stored in the dirt information memory.
When the seam is detected, the above-mentioned X and Z parts to be masked are known, so addresses 0 of reference memories A and B are called and dirt detection is performed while comparing with the dirt information detected in real time. conduct. When scanning for one screen is completed after starting dirt detection, the information stored in the dirt information memory is compared with the corresponding mask information in the reference memory B.

Next, with reference to FIG. 32, a specific example of masking and processing of information detected during the stain detection operation will be described.

In the surface detection operation, reference line detection is first started (line g in FIG. 31). Next, when the time required to scan the bent portion of the side seam has elapsed (line a in FIG. 31), the detection data storage mode terminal _M1 of the mask pattern circuit becomes high level, and the mode selection gates 350, 352, and 378 are turned on. , are set to _M1 mode by selects 1, 2, and 3, respectively, and the address signal CN ₁ from the counter 406 is sent to the reference memory A, and the address signal from the counter 404 is sent to the reference memory A.
CN ₂ is in reference memory B, counter 362
The address signal CN ₀ from is output to the dirt information memory. At this time, the reference memory 300
A and 300B are in read mode, and dirt information memory 268 is in write mode. Since the detected data accumulation mode terminal _M1 becomes high level, one input of AND gate 360 becomes high level via OR gate 358, and counter 362 counts the main scanning clock. As a result, the address signal in the sub-scanning direction is sent to the dirt information memory 268 in the same way as when writing the mask pattern.

On the other hand, detection data containing only dirt information determined to be dirt from the determination circuits 290 and 292 is combined by an OR circuit 380 and input to a shift register 382. In this detection data, white is 0.
This is a low level signal representing 1, and black is a high level signal representing 1, and is a high level signal opposite to mask pattern information. Therefore, if either of the detection data output from the determination circuits 290, 292 represents black, it is regarded as black and is output from the OR circuit 380. Furthermore, since the relationship between the black and white of this detection data and the signal level is opposite to that of the mask pattern information, stains can be determined by calculating the logical product of the detection data and the mask pattern information. That is, when the mask pattern information is black, the signal representing it is at a low level, so the AND of the detected data and the mask pattern information also becomes a low level, regardless of the detected data, and the detected data is masked. On the other hand, when the mask pattern information is white, the signal representing it is high level, so the AND of the detection data and mask pattern information is the same as the state of the detection data, and even if it is a high level signal representing black dirt. In this case, a high level signal is obtained, and it can be finally determined that it is dirt.

The shift register 382 is constructed by connecting n N-bit shift registers for one main scan in series, and connecting the output of each shift register to an OR gate 384. And or gate 384
The output of is applied to an m-bit shift register 386, and the output of each stage of the shift register 386 is applied to an OR gate 388. As a result, if even one of the n pixels adjacent to each other in the sub-scanning direction is black, it is determined to be black, and furthermore, if even one of the m pixels adjacent to each other in the main scanning direction is black When it is determined that the image is black, the range of the stain is expanded and the stain information is not lost when compressed and stored in the stain information memory 268. Dirt information memory 26
8 stores the data from the OR gate 388, but compresses it to 1/m by reducing the address frequency to 1/m of the image frequency, similar to writing the mask pattern to the reference memory. memorize it.

In this way, data is stored in the dirt information memory 268 as scanning progresses. and,
When the first side seam is detected (line b in FIG. 31), the seam detection circuit of the sub-scanning direction reference coordinate setting circuit 272 outputs a high-level seam detection signal to the seam 1 output line, and the AND gate The output of 390 becomes high level, and the latch 392 becomes the counter 3.
62 in the sub-scanning direction, that is, the address of the side seam in the dirt information memory 268.

Additionally, AND gate 394 is also opened, flip-flop 396 is set, and AND gate 400 is set.
and one input of 402 is held at high level. As a result, the main scanning clock is applied to the count-up input UP of the up-down counter 404, and at the same time as the counter 404 counts addresses, the counter 406 counts the main scanning clock. The count signal from the counter 404 is supplied to the reference memory 300B as an address in the sub-scanning direction from the side seam, and the count signal from the counter 406 is similarly supplied to the reference memory 300A as an address in the sub-scanning direction from the side seam. Supplied as a signal.

The mask pattern information P ₁ and P ₂ read from the reference memories 300A and 300B are output to the determination circuits 290 and 292, and the determination circuit
The mask pattern information and the detection data are collated in real time from the scanning line b in FIG.

The counter 4 counts up until all the information _P1 stored in the reference memory 300A is read out.
06, the decoder 408 outputs a low level signal to the AND gate 402, and the counter 4
Sending of the address signal of 06 is stopped.

In this way, when one rotation of the paper cup is completed, that is, when the scanning line d in _{FIG .} becomes high level. This ends the real-time processing of the determination circuit. Furthermore, the mode selection gate 35
2,378 by entering _M2 mode,
Address signal CN ₀ from counter 362 is output to reference memory B, and address signal CN ₂ from counter 404 is output to dirt information memory.

Post-processing mode terminal _M2 becomes high level,
The flip-flops 356 and 396 are reset, and the detection data accumulation mode terminal _M1 goes low and the AND gates 360 and 400 are closed, so that the counters 362 and 404 are reset.
stops counting. Furthermore, the counter 36
A latch write signal is applied to latch terminal L of latch 2,404, and the address number of the second seam in the mask pattern information written in latch 376 is written to counter 362, and then written to latch 392. The address number of the first seam in the dirt information memory 268 is written into the counter 404. Furthermore, one input of the AND gates 410 and 412 is connected to the post-processing mode terminal _M2 , so it is at a high level, and the main scanning clock is connected to the counter 36.
2,404 is applied to the countdown input DOWN. And those counters 362, 404
The address numbers outputted from the address numbers that become smaller in sequence are sent to the reference memory 300B and the dirt information memory 268. As a result, the reference memory 300B reads the mask pattern from the scanning line e to the left in FIG. 31, and the dirt information memory 268 reads the dirt information from the scanning line b to the left in FIG. Thereby,
AND circuit 41 forming mask matching circuit 294
4 compares the mask pattern on the left side of the seam with the dirt information, and if dirt is found in the unmasked area, outputs a high level signal representing dirt. This verification operation is performed by the counter 40.
This process continues until the address number 4 becomes 0. Therefore, from scanning lines e to d of the mask pattern,
Scan lines b to a of the stain information are compared.
In this way, the scanning lines a to d of dirt information are masked using the mask patterns of scanning lines b to d and d to e.

According to the above-described processing, no matter where scanning starts, it can be matched with the mask pattern in one scan, so the time required for scanning can be shortened and high-speed processing can be achieved. can. This is especially true when images can only be taken once, such as when an article whose part to be masked is in a fixed positional relationship with respect to the reference line is placed in a random orientation and transported by a conveyor that moves in one direction. ,effective.

The comprehensive judgment circuit 276 includes judgment circuits 290 and 292 in the main scanning direction and sub-scanning direction, and the mask matching circuit 2.
The pass/fail judgment results from 94 are integrated, a comprehensive judgment is made, and the results are output to the display device 204 and the distribution control device 206. In this comprehensive judgment, only the judgment circuit and the mask matching circuit judge whether it is good or bad, so if either one of them is judged to be bad, it is determined to be defective.

The display device 204 displays the number of soiled items of each defective product,
This includes printing out the total amount of dirt, etc., and observing defective products using a monitor. An appropriate method may be selected depending on the needs of the user, and any of these methods can be configured using known techniques. Next, an embodiment using a monitoring monitor will be described. FIG. 33 is a system diagram showing the system in which an image that has undergone only preprocessing, an image of a dirty portion, a mask pattern, and a whole image of dirt can be selected by the display selection circuit 416 and displayed on the monitor 418. The output of the preprocessing section has its phase corrected by a phase correction circuit 420, and is outputted to a monitor 418 via a monitoring memory 422. In the case of only non-defective products, the above images are displayed one after another. From the judgment circuit in the main scanning direction or sub-scanning direction, an OR circuit 424
Images whose size of dirt has been determined are sent one after another through the monitor 422 and stored in the monitoring memory 422. When a defective signal is sent from one of these judgment circuits to the comprehensive judgment circuit, a control signal is sent from the general judgment circuit to the monitoring memory, which switches the image that has undergone the above preprocessing and determines that it is defective. The image of the contaminated area is displayed for a predetermined period of time. When necessary, the display selection circuit 416 can be operated to manually view the image as a still image. All images of the mask pattern and dirt can also be displayed manually. The purpose of projecting the mask pattern is to confirm what the written pattern is, and the purpose of displaying the entire image of the stain is to observe the distribution of the stain over the entire area of the image of the defective item. be. Since this entire image has been compressed, detailed images must be obtained from partial images from the determination circuit.

The distribution of good products and defective products is performed by operating the distribution control device 206 based on the defect signal from the comprehensive determination circuit. Since the time from the start of the inspection until the classification of good and defective items is determined by each system, the distribution control device uses a known appropriate means depending on each system. be able to. Next, the embodiment will be explained with reference to FIG. 34. As mentioned above, the paper cup conveyance device is circular, with cup holders installed at six locations around the periphery to insert the paper cup, and the paper cup is rotated intermittently at 1/6 revolutions at a time while simultaneously rotating on its axis. It performs various operations such as feeding, pushing, inspecting, discharging defective products, and discharging non-defective products.
Therefore, when the revolution stops, the comprehensive judgment circuit 276
The judgment signal from 2 is sent to the two-stage shift register 426, the shift register advances by one step, and the shift register 426 outputs data two steps earlier. That is, when the inspected paper cup reaches the defective product discharge station from the detection station, the shift register 426 outputs a comprehensive judgment signal. When defective, shift register 42
The output of No. 6 is supplied to the solenoid valve 108 via the buffer/drive amplifier 428, and defective products are discharged. When the item is good, there is no output from the shift register, so the item is discharged as a good item in the next step.

In the embodiments described above, if high speed is not required, the dirt information memory 26
8. Mask verification circuit 294, dirt information compression circuit 2
98 need not be provided. In this case, after detecting the side seam, the paper cup is rotated one rotation, and the determination circuits 290 and 292 perform mask processing in real time on the detection data for one rotation after the side seam has been detected. As a result, as described above, it is necessary to rotate the paper cup two revolutions at most before the paper cup stain detection process is completed, but on the other hand, there is an advantage that the stain information memory 268 and the like are not required.

As is clear from the foregoing, in the above-described embodiments of the present invention, the conveying device can accurately position the paper cup at the inspection position without deforming it, and deform the paper cup at the inspection position. The paper cup can be rotated at a constant speed without causing eccentricity or lifting, and without requiring acceleration time. Since there is no part to remove dirt, even the smallest dirt can be reliably detected at high speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an embodiment of an automatic paper cup surface inspection device according to the present invention, FIG. 2 is a top view of an embodiment of a conveying device according to the present invention, and FIG. 4 is a partial sectional view taken along the line - in FIG. 2, FIG. 5 is a diagram showing the relationship between the sun gear and the planetary gears, and FIG. 6 is a partially omitted front view of the conveyance device.
2 is a sectional view taken along the line 2, FIG. 7 is a perspective view of the paper cup pushing mechanism, and FIG. 8A is a
Fig. 8B is a layout diagram of a paper cup and a camera when the paper cup is imaged from directly above;
Fig. 8C is a layout diagram of the paper cup and the camera when the paper cup is imaged from three sides, Fig. 8D is a schematic diagram of the image obtained when the paper cup is imaged from diagonally above, and Fig. 9A is a diagram of the arrangement of the paper cup and the camera when the paper cup is imaged from three sides. A side view showing the relationship between the paper cup and the optical axis of the camera when the cup is imaged from diagonally above. Figure 9B is a top view of the imaging arrangement shown in Figure 9A. Diagram 1 showing the relationship between the inclined imaging plane and the inclined inspection plane.
1 is a diagram showing the direction of illumination that creates a shadow on the seam of a paper cup; FIGS. 12A, 12B, and 12C are schematic diagrams of the means for illuminating the inspection surface of the paper cup; and FIG. A block diagram showing the configuration of the detection processing device, FIG. 14A is a schematic perspective view of a paper cup,
Figure 14B is a developed view showing the mask pattern for the paper cup in Figure 14A, Figure 15A and
Figure 5B is a graph showing the level deformation of the detected analog pixel signal and the waveform-shaped signal for one scan, and Figure 16 is a graph showing the relationship between the analog pixel signal and the digital pixel signal converted from it. , FIG. 17A, FIG. 17B, and FIG. 17C,
FIG. 18 is a diagram showing the effect of contour enhancement processing, FIG. 19A is a diagram showing the positional relationship of pixels sampled when performing contour enhancement processing and smoothing processing,
FIG. 9B is a diagram showing the effect of smoothing processing, FIG. 20 is a block diagram showing the configuration of the contour enhancement/smoothing circuit, FIGS. 21A and 21B are waveform diagrams showing the effect of dynamic averaging, Figures 22A and 22B are
23A to 23F are waveform diagrams showing the relationship between the pixel signal subjected to dynamic averaging processing, the threshold for detecting deep dirt, and the detected dirt signal; FIG.
The figure is a waveform diagram showing signal processing for detecting light dirt, FIG. 24 is a diagram showing "chips" and "stains" in image information, and FIGS. 25A and 25B are
A graph showing the range of pixels sampled during mesh filter processing, FIG. 26 is a configuration diagram of a shift register circuit used in the detection axis conversion circuit,
FIG. 27 is a block diagram showing the schematic configuration of the reference line detection circuit, FIGS. 28A, 28B, and 28C.
The figure shows a developed diagram and a waveform diagram of the side surface of a paper cup showing the signal processing process when detecting the side seam of a paper cup, FIG. 29 is a block diagram showing the specific configuration of the reference line detection circuit, and FIG. 30 31 is a developed diagram showing the relationship between paper cup scanning, mask processing, and stain detection. FIG. 32 is an explanatory diagram for explaining the related operations of each circuit. FIG. 33 is a block diagram showing an example of the configuration of the display device, and FIG. 34 is a block diagram showing an example of the configuration of the distribution control device. 10... Conveyance device, 12... Detection processing device, 14...
Surface detection device, 16... Processing discrimination device, 20... Paper cup, 22... Cup holder, 24... Indexing table, 26... Frame of transport device, 28... Rotating shaft,
30...Boss, 34...Rotation axis, 42...Planetary gear, 4
4... Sun gear, 48, 52... Gear, 50... Rotating shaft, 53e, 54b, 74... Motor, 56... Cup accumulating tube, 58... Cup supply screw, 78...
Hole, 80... Hollow chamber, 82... Radial hole, 84... Annular channel, 86... Hose, 88, 92... Annular member, 90... Hole, 96... Arm, 98... Vacuum chamber,
100, 102... High pressure chamber, 108, 110... Solenoid valve, 112... Pushing mechanism, 132... Camera, 13
4...Line sensor, 136...Objective lens, 138
...Camera, 148...Inspection surface, 150...Imaging surface, 1
52... Seam of paper cup, 156... Point light source, 158
...Cylindrical convex lens, 160...Concentrated illumination area, 162...Spherical convex lens, 164...Cylindrical reflective surface, 172...Top edge of paper cup, 174...
Top flange of paper cup, 176... Side seam of paper cup, 178... Side bottom seam of paper cup, 18
0...Bottom hole of paper cup, 200...Pretreatment section, 20
2...Data processing unit, 204...Display device, 206...
Distribution control device, 208...Clock, 210...Preamplifier, 212...Waveform shaping circuit, 214...A/D
Conversion circuit, 216... Contour enhancement and smoothing circuit, 26
4... Main scanning direction dirt information detection circuit, 266... Sub scanning direction dirt information detection circuit, 268... dirt information memory, 270... Mask pattern circuit, 272... Sub scanning direction reference coordinate setting circuit, 274... Main scanning direction reference coordinate setting Circuit, 276... Comprehensive judgment circuit, 294
...Mask matching circuit.

Claims (1)

[Claims] 1. A rotary indexing table that is driven intermittently;
a cup holder disposed around the indexing table, supported so as to be able to rotate relative to the indexing table, and having a concave portion that tightly receives the lower part of the paper cup; and a cup holder that rotates relative to the rotation axis of the indexing table. A sun gear that is freely and coaxially mounted and driven continuously, a planetary gear that is fixed to the rotation axis of the cup holder and meshes with the sun gear, and a supply means for supplying paper cups to the cup holder are arranged. the paper cup held in the cup holder; Katsupu is
As the indexing table rotates, it revolves together with the indexing table, and as the sun gear continues to rotate, it rotates at a constant speed through the planetary gears independently of the rotation of the indexing table. a paper cup transport device; an illumination means for illuminating the paper cup rotating on its axis in the inspection station; A surface detection device comprising a line sensor composed of a solid-state image sensor and outputting an analog pixel signal; and a preprocessing device that receives the analog pixel signal output from the surface detection device, shapes its waveform, converts it into a digital signal, and outputs it. and a data processing section that receives digital pixel signals from the preprocessing section and performs dirt detection, and the data processing section receives digital pixel signals from the preprocessing section and detects dirt in the main scanning direction. a detection axis conversion circuit for converting pixel data into pixel data in the sub-scanning direction; a main-scanning direction reference coordinate setting circuit for detecting a reference axis in the main-scanning direction in response to a digital pixel signal from the detection-axis conversion circuit; a sub-scanning direction reference coordinate setting circuit that receives digital pixel signals from the pre-processing section to detect a reference axis in the sub-scanning direction; and a sub-scanning direction reference coordinate setting circuit that receives digital pixel signals from the pre-processing section and detects a reference axis in the sub-scanning direction; A mask pattern circuit generates pattern information, and for areas to be masked by receiving digital pixel signals from the preprocessing section, dirt is detected in the main scanning direction while receiving mask information from the mask pattern circuit and performing mask processing. A main scanning direction contamination detection circuit having a first judgment circuit that performs processing, and a masking process for a portion to be masked by receiving a digital pixel signal from the detection axis conversion circuit by receiving mask information from the mask pattern circuit. a sub-scanning direction dirt detection circuit having two judgment circuits that perform dirt detection processing in the sub-scanning direction while performing the above-mentioned dirt detection processing; a detection processing device comprising a judgment circuit; and a sorting and discharging device of the paper cup conveying device to separate non-defective items from defective items based on the comprehensive judgment result. Surface inspection equipment. 2. The automatic paper cup surface inspection apparatus according to claim 1, wherein the indexing table and the sun gear are each driven by independent motors. 3. A hole is formed in the bottom of the cup holder to pass through the hollow chamber of the rotating shaft, and the hollow chamber of the rotating shaft is communicated with a vacuum source so that the paper cup is held by suction on the cup holder. An automatic surface inspection device for paper cups according to claim 1 or 2, characterized in that: 4. The invention further comprises a pushing mechanism for pushing a paper cup received into the cup holder into the cup holder to properly position it during a period when the indexing table is not in use. An automatic surface inspection device for paper cups according to any of items up to 3. 5. The automatic surface inspection of paper cups according to claim 4, wherein the pushing mechanism includes a piston cylinder device and a pushing disk that moves up and down by being driven by the piston cylinder device. Device. 6. Around the indexing table, at least a supply station, an inspection station, and a discharge station are provided in the order, the supply means is provided in the supply station, and a hole is formed in the bottom of the cup holder, and the cup holder is provided with a hole. A hollow chamber having a communication hole communicating with the hole in the bottom of the cup holder and extending in a radial direction is formed in the rotation axis of the cup holder, and the index table rotatably holds the rotation axis of the cup holder. A boss member having an annular channel surrounding the radial hole is fixed to the indexing table, and a first annular member having a hole communicating with the annular channel is fixed to the revolution axis of the indexing table. A second annular member having a hollow chamber opened to the first annular member and extending in the circumferential direction so as to selectively communicate with the hole of the first annular member is rotatable about the revolution axis. The second annular member is fixedly received and supported on the frame of the apparatus, and the hollow chamber of the second annular member extends circumferentially to accommodate a supply station and a test station, and a vacuum chamber connected to a vacuum source and a discharge station. The paper cup is divided into a high-pressure chamber correspondingly extending in the circumferential direction and connected to a pressure source, and when the paper cup is fed to the cup holder at the supply station, it is held by suction on the cup holder and thereafter held by suction until it reaches the inspection station. continue,
The automatic surface inspection device for paper cups according to claim 1 or 2, wherein the paper cup is ejected from the cup holder upon reaching the ejection station. 7. Claims characterized in that there is a pushing station between the supply station and the inspection station, and a pushing mechanism is provided for pushing the paper cup suctioned and held in the cup holder into the cup holder and positioning it appropriately. The automatic surface inspection device for paper cups according to item 6. 8. The discharge station includes a defective product discharge station and a non-defective product delivery station, and
The high pressure chamber of the annular member includes a first high pressure chamber that extends in the circumferential direction and is connected to a pressure source via a first valve so as to correspond to a defective product discharge station, and a first high pressure chamber that corresponds to a good product delivery station. It is divided into a second high pressure chamber extending in the circumferential direction and connected to a pressure source via a second valve, and paper cups can be sorted by selectively opening the first valve and the second valve. An automatic surface inspection device for paper cups as claimed in claim 6 or 7, characterized in that the apparatus is made by: 9. Claims 1 to 8, characterized in that the illumination means includes a point light source and a condensing cylindrical lens, and is configured to concentrate light in an elongated area in the scanning direction. An automatic surface inspection device for paper cups described in any of the above. 10. The illumination means comprises a point light source and a cylindrical reflecting mirror for condensing light, and is configured to concentrate light in an elongated area in the scanning direction. An automatic surface inspection device for paper cups as described in any of Item 8. 11. Claims 1 to 1, characterized in that the illumination means includes a rod-shaped light source and a circular convex lens for condensing light, and is configured to concentrate light in an elongated area in the scanning direction. An automatic surface inspection device for paper cups as described in any of Item 8. 12. Claim 1, characterized in that the illumination means is placed at a position away from a plane containing the line sensor and the rotation axis of the paper cup so as to cast a shadow on the side seam of the paper cup. An automatic surface inspection device for paper cups according to any one of items 1 to 11. 13 In the surface inspection device, the imaging surface of the line sensor is tilted in a direction opposite to the direction in which the inspection surface of the paper cup is tilted with respect to the optical axis of the imaging lens, so that the depth of field is deepened. An automatic surface inspection device for paper cups according to any one of claims 1 to 12. 14 The detection axis conversion circuit includes a shift register n whose number of dots is the number N of pixels in one scan in the main scanning direction.
n shift registers are connected in series, the output pixel data of each shift register is added to a dynamic averaging circuit, and the output of the dynamic averaging circuit is output as a central shift register of n shift registers. Automatic surface inspection device according to scope 1. 15. The automatic paper cup surface inspection apparatus according to claim 1, wherein the sub-scanning direction reference coordinate setting circuit detects a side seam of the paper cup as a reference axis. 16 The sub-scanning direction reference coordinate setting circuit includes a circuit that totals input digital pixel signals for each scanning line, a reference line emphasis circuit that subtracts a certain value from the total value, and a dynamic control circuit for the output of the reference line emphasis circuit. The circuit includes a circuit that calculates an average value, a subtracter that subtracts the dynamic average value from the output of the reference line emphasis circuit, and an adder that adds the output of the subtracter and the reference value, and the output of the adder is 0 or 0. 16. The automatic surface inspection apparatus according to claim 15, wherein when negative, the scanning line is used as a reference line. 17 After the start of each scan, the main scanning direction reference coordinate axis setting circuit detects when the image signal changes from a dark state to a bright state, and performs mask processing on the top edge and the seam between the side and bottom surfaces of the paper cup. 17. The automatic paper cup surface inspection apparatus according to claim 1, wherein a signal for determining the surface of a paper cup is output to the first determination circuit. 18 The preprocessing circuit includes a first adder that calculates the sum _g1 of digital pixel signals for pixels on the upper, lower, left, and right sides of the digital pixel signal E that are adjacent to each other in coordinates; The second step is to calculate the sum _g2 of the digital pixel signals for the upper right, lower right, upper left, and lower left pixels adjacent to
a first arithmetic circuit that outputs g ₁ or (g ₁ +g ₂ )/2 as peripheral data g depending on the selection;
A second operation that receives a coefficient circuit that provides a weighting coefficient K, peripheral data g, a weighting coefficient K, and a digital pixel signal E, and calculates an edge enhancement signal (K+4)-g/K and a smoothed signal KE+g/K+4. Claims 1 to 1 include an edge enhancement/smoothing circuit comprising a circuit and a selection circuit that selectively outputs an edge enhancement signal and a smoothed signal.
The automatic surface inspection device for paper cups according to any one of Item 7. 19 The dirt detection circuit in the main scanning direction and the sub-scanning direction includes a first dynamic average value circuit that calculates a first dynamic average value of input digital pixel signals, and a first dynamic average value circuit that calculates the first dynamic average value from the input signal. a subtracter for subtracting; a circuit for slicing the output of the subtracter at a sufficiently deep first threshold to detect high-density dirt; and a second circuit for calculating a second dynamic average value from the output of the subtracter;
a dynamic average value circuit, a circuit for slicing this second dynamic average value with a second threshold shallower than the first threshold to detect a range of dirt with low concentration, and a circuit for enlarging the range of this dirt. and a dirt information extraction circuit configured to slice the output of the subtracter at a sufficiently shallow third threshold using this expanded range as an inspection section to detect low-density dirt. An automatic surface inspection device according to any one of claims 1 to 18. 20 The dirt detection circuit in the main scanning direction has a means for masking only the portion to be masked that is perpendicular or oblique to the main scanning direction, and the dirt detection circuit in the sub-scanning direction has means for masking only the portion to be masked that is perpendicular or oblique to the sub-scanning direction. 20. The automatic surface inspection apparatus according to claim 19, further comprising means for masking only the desired portion. 21 The mask pattern of the upper bend of the side seam is stored in the first reference memory,
The dirt detection circuit starts dirt detection with a delay of a time corresponding to the length of the mask pattern in the first reference memory in the sub-scanning direction from the start of scanning the paper cup. An automatic surface inspection device for paper cups according to any one of items 1 to 20. 22 For the inspection range where the position of the mask pattern is determined by the sub-scanning direction reference axis, a dirt information memory and a mask matching circuit are separately provided, and the first and second judgments are performed until the sub-scanning direction reference axis signal is received. The dirt information from the circuit is stored in the dirt information memory, and after the reference axis in the sub-scanning direction is detected, the dirt information is detected while performing mask processing based on the mask pattern information in the first and second determination circuits. and outputting it to a comprehensive judgment circuit, and after completion of scanning the entire range of the object to be inspected, the dirt information in the dirt information memory and the corresponding mask pattern in the reference memory are collated by the mask matching circuit; 22. The automatic surface inspection apparatus according to claim 1, wherein the dirt information from the verification circuit is output to a comprehensive judgment circuit. 23. Claims characterized in that the dirt information stored in the dirt information memory and the corresponding mask pattern in the reference memory are compared in order from the highest address number to the lowest address number. The automatic surface inspection device for paper cups according to item 22.