JP2605581B2 - How to discharge falling cans, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for discharging falling cans and the like, which detects and discharges falling cans, contact cans, etc. from arranged cans.

[0002]

2. Description of the Related Art In a can-making process, a currently used can container is printed on its outer peripheral surface in accordance with its contents.
Further, drying is immediately performed in an oven or the like after printing. For example, in deep-drawing cans or drawn-ironing cans whose inner surface or inner and outer surfaces are coated with a polyester film or the like, which has been recently developed in consideration of environmental issues and is used as a can for food and beverage, printing on the outer peripheral surface Is transferred to a carrying oven by a conveyor (oven net), where drying is performed. In this case, due to the movement of the conveyor during the movement, air blown in the oven, etc., the cans may fall down before the ink in the printing section dries or the cans may come into contact with each other. As a result, defective printing cans are generated. Therefore, it is necessary to detect and discharge such a defective printing can.

Conventionally, falling cans, contact cans, and the like have been selected from cans transferred from a carrying oven in an aligned state (these are sometimes referred to as "falling cans" or "defective cans" in this specification. ) To detect and discharge
It was done manually.

[0004]

However, the conventional method of manually detecting and discharging a falling can from the cans transferred from the carrying oven requires time for the detection and discharge operation. There was a problem of lack of accuracy. The present invention has been made in view of the above circumstances, and automatically detects a falling can and the like without manual intervention from cans transferred from a carrying oven and discharges the same. Accordingly, it is an object of the present invention to provide a method of discharging a falling can or the like, which can quickly and accurately discharge defective printing cans.

[0005]

In order to achieve the above object, a method for discharging falling cans or the like according to the present invention uses a video camera to photograph a plurality of cans conveyed in a row to obtain image data. The image data is subjected to binarization processing and labeling processing, and then the value obtained by performing the labeling processing is compared with a set value to detect non-defective cans. performs determination of whether the can, when it is determined that the collapse cans is Yes so as to discharge the collapse around the can and the can or the like, preferably, La
In the belling process, the image data is binarized to obtain a shadow.
From the center of the area of this can shadow and / or the area of the can shadow
In the process of obtaining the length of the direction, the determination of whether the part determined to be a missing can is actually a state where the can is missing or a state where a falling can exists is determined as a missing can. When the can row including the portion is transferred to the suction conveyor by the magnet or the vacuum, it is determined whether or not the can has fallen.

[0006]

According to the present invention, when there are defective cans, such as falling cans or contact cans, in cans transferred in a line from the oven, these defective cans are binarized and processed. After performing labeling processing and detecting and discharging, and when it is determined that the part includes a missing can part, it is determined whether the part is in a state where the can is actually missing or a state where a falling can exists. When it is determined that a falling can exists, the falling can is discharged. In addition, in order to reliably discharge the defective printing cans, not only the falling cans and the contact cans but also the surrounding cans that may be affected by the falling cans and the contact cans are discharged.

[0007]

Embodiments of the present invention will be described below. First, an example of an apparatus for implementing the method of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic overall configuration diagram of the apparatus.
FIG. 2 is a side view showing the detection state of the aligned cans and dropped cans.
As shown in FIGS. 1 and 2, the apparatus according to the present embodiment includes a carrying oven 10 for drying printed cans, a video camera 20 for photographing aligned cans, and image data processing for processing photographed image data. A unit 30 and a sequencer 40 for determining a can to be discharged based on a signal from the image data processing unit 30 and the like.

The oven 10 dries a can having an outer peripheral surface printed in a printing step (not shown). At this time, the cans are sent to the oven 10 in a state where the cans are arranged in a row on a predetermined number (17 in this embodiment) of the conveyor 11. The cans dried in the oven 10 are transferred from the oven 10 by a conveyor 11 as shown in FIG.

As shown in FIG. 1, a video camera 20
The first and second cameras 20a and 20b,
The two cameras 20a and 20b simultaneously image three rows of 17 cans (three rows before and after the inspection target row) at the same time.
Here, the center of the first camera 20a is the fifth can,
The center of the second camera 20b is arranged at the upper part of the outlet side of the oven 10 so as to correspond to the fourteenth can. The three rows of cans to be photographed are illuminated from above and below by a lighting device 21 arranged in the front and rear direction of the camera 20.

The image data processing unit 30 sends a drive signal for driving the electronic shutter, that is, shooting with the video cameras 20a and 20b,
Video camera controllers 31a and 31b for setting the shutter mechanism conditions and the shooting method such as the shutter time of 20b
Is provided. The image data processing unit 30 includes an image capture control unit 32 that controls the video camera controllers 31a and 31b, image memories 33a and 33b that digitize and store images captured by the video cameras 31a and 31b, Binarization, labeling,
It has a labeling processing unit 34 for performing a series of processes such as grouping and block classification. A monitor 35 and a keyboard 36 are connected to the image data processing unit.

The sequencer 40 includes processing data from a labeling processing unit, an output signal of a sensor (transmission type photoelectric sensor) 41 for detecting an alignment state of cans transferred from the oven 10, and a drop sensor (transmission type photoelectric sensor). A series of processing is performed in accordance with the output signal from 42 and a preset processing procedure, the cans to be discharged and the cans to be discharged are selected, and a signal based on the selection result is transferred to the magnet elevator 50 for transferring the cans. As an operation signal to the electromagnet 51. Each electromagnet 51 in the magnet elevator 50 is arranged so as to correspond to each can, and operates independently for each can row described later.

Next, the method of the first embodiment of the present invention performed by using such an apparatus will be described. FIG. 3 is a flowchart of the method of the first embodiment. Capture of image data (101) The capture of image data is started by a signal from the sensor 41. That is, when the detection of a falling can or the like is started,
Based on the signal from the sensor 41, the sequencer 40
The shutter instruction signal PH1 is output to the image acquisition control unit 32. Thereby, the image capture control unit 32 outputs the shutter signal HSC to the video camera controllers 31a and 31b. The video camera controllers 31a and 31b that have input the shutter signal HSC are the video cameras 20a and 31b.
A camera controller signal is output to 20b to perform shooting. When the video cameras 20a and 20b take a picture, the camera controllers 31a and 31b send an image to the image memory 33.
The video signal is sent to a and 33b. On the other hand, the image capture control unit 32 outputs the image capture signal TRG to the image memories 33a and 33b, and stores the video signal as image data in the image memories 33a and 33b at a predetermined timing. FIG. 4 shows a timing chart for taking in image data (video signal). The capture of the image data is performed simultaneously by two video cameras 21a and 21b (video controllers 31a and 31b and image memories 33a and 33b). In addition, the sensor 41 detects a predetermined time (for example, 640 m) due to disorder of the can alignment state or contact of the can.
s) In the light-shielded state, the sequencer 40 forcibly outputs a shutter signal to the image capture control unit 32 to capture an image.

In the case of this embodiment, the image capturing is performed by a random shutter system. This random shutter system generates image data in real time with respect to a shutter signal, and all image data becomes noise components unless a shutter signal is input. Therefore, the image data of the effective component is stored in the image memory 33 according to the image capture signal from the image capture control unit 32.

The image data is converted into digital values of 256 gradations and stored in the image memory 33 in a state of, for example, 512 divisions in the horizontal direction and 256 divisions in the vertical direction. The 256 gradation values are bright (white) when the value is large, and dark (black) when the value is low. The can to be subjected to the present method is placed on a conveyor with the can shadow up and dried.
For example, in a deep drawing can having a polyester film containing a white pigment adhered to the outer surface, the shadow of the can is bright and the conveyor portion is dark. Therefore, can shadows can be confirmed by extracting bright portions. That is, the image data is binarized, and a pixel having an arbitrary brightness level or higher is obtained to extract a can shadow. FIG. 5 shows an example of the extraction result.

Labeling processing (102) The labeling processing section 34 obtains the area of the black portion, the center of the area, and the length in eight directions from the center of the area based on the extracted binary data shown in FIG. Perform processing. FIG. 6 shows the result. Along with the labeling processing, a group of cans in one row in three rows before and after the cans in the column to be inspected is grouped into one group, and a portion corresponding to the can row direction is divided into 17 blocks. FIG. 7 shows the result. At the time of grouping, label numbers 1 to 17 are assigned to each can (see FIGS. 6 and 7).

Judgment as to whether or not the can is good (103) When the labeling process is performed, the area of the black portion of the group having the falling can and the contact can (defective can) becomes larger than the area of the black portion of the good can group, and The length in eight directions from becomes longer. Therefore, by comparing this area and the length in the eight directions with the set value, it is determined whether or not the cans in the target group are non-falling cans and non-contact cans. A group in which a black portion cannot be extracted from the inspection target row is also determined as a defective can group that is not a good can.

In addition, based on the position of the area center and the block division area data, it is determined in which block the target group including the defective can is located (see FIG. 7). As a result, in the system of the first video camera 20a, the fourth block,
In the system of the second video camera 20b, the twelfth block and the fourteenth block (the area center of the label number 12 is
Is located in the block) is determined to be not a good can.

Judgment of defective can and setting of defective block
( 104, 105, 106 ) It is determined whether the cans in the group determined not to be good cans are fallen cans, contact cans, or missing cans. This determination is made by the labeling process described above. That is, when the labeling process is performed, the area of the black portion in the case of the falling can and the contact can becomes larger than the area of the black portion of the good can group, and the length in the eight directions from the center of the area increases. Therefore, by comparing this area and the length in the eight directions with the set value, it is determined whether or not the cans in the target group determined to be not good cans are not fallen cans or contact cans. as a result,
The group including falling cans and contact cans is judged as having defective cans,
Three rows of cans (3 rows × 3 rows, totaling 9 cans) including the left and right of the group having the defective cans are set as defective blocks.

Discharge of Cans of Bad Block (107) Upon receiving the above result from the labeling processing unit 34, the sequencer 40 demagnetizes the electromagnet 51 corresponding to each can in the bad block of the magnet elevator 50.
As a result, the cans in the defective block are transferred to the conveyor 11.
When the vehicle is transferred from the conveyor to the magnet elevator 50, it is dropped and discharged from the conveyor 11 without being held by the magnet elevator 50. In this way, by discharging all the cans around the falling cans and contact cans, not only defective cans such as falling cans and contact cans, but also those cans may be adversely affected. Prevents defective printing cans from being sent to the next process by mistake, and completes discharge of defective printing cans.

In the next step of transferring the good cans (108, 109 , 110 ) , the group including the cans determined to be good cans is sent from the sequencer 40 if there is no group having a defective can in an adjacent group. Is attracted and held by the corresponding electromagnet 51 of the magnet elevator 50 and transferred to the next step. Also, the group including the portion determined to be a missing can is similarly transferred to the next step if there is no group having a defective can in an adjacent group. In this way, the falling cans and the contact cans themselves, which may have a printing failure, and the cans which may be affected by these cans and have a printing failure, are discharged.

Next, a second embodiment of the method of the present invention will be described with reference to FIG. This embodiment is an example of a method in which a misprinted can is prevented from being transferred to the next process together with a good can by erroneously determining a fallen can as a missing can. That is, when a black-and-white camera is used as the video camera 20, if the design of the can is dark, the falling can cannot be detected, and the can is erroneously determined to be a missing can. Therefore, it is determined whether the part determined to be a missing can is really a missing can or a falling can. This determination is made as follows.

Detecting the presence / absence of falling cans (111) It is determined whether or not the non-good cans of the target group are defective cans (104). When it is determined that they are not defective cans (104)
Assumes that the can is a missing can (109 '). Then
The drop sensor 42 detects whether or not there is a drop in the cans in the row to be inspected including the portion determined to be missing from the conveyor 11 to the magnet elevator 50 (111). Since the falling can has a relatively wide space between the falling can and the electromagnet 51 of the magnet elevator 50, the falling can cannot be transferred from the conveyor 11 to the magnet elevator 50. Therefore, when the drop sensor 42 detects a drop,
The sequencer 40 determines that a fallen can has been present in the missing can part (112). Then, through the same procedure (105, 106, 107) as in the first embodiment, the group including the falling can and the groups on the left and right sides thereof are discharged as defective blocks. In the case of the method of the second embodiment, the cans sucked and held by the magnet elevator 50 are dropped and discharged by demagnetizing the corresponding electromagnets in accordance with an instruction from the sequencer 40. As a result, it is possible to prevent the transfer of a can having a possibility of defective printing due to contact with the falling can to the next process.

On the other hand, when there is no signal from the drop sensor 42 indicating that a drop can has been detected, the sequencer 40 determines that the drop can portion is still a drop can (113), and determines that the surrounding cans are good. It is transferred to the next step by the magnet elevator 50. In this way, the condition of the cans sent out of the oven 10 is inspected, and the cans with possible printing failure are discharged.

The present invention is not limited to the above-described embodiment, but includes various modifications. For example, if the number of cans in a row is about 10 or less, a single camera system may be used. It is possible. Further, the present invention can be used not only for detection and discharge of a falling can or the like for a can sent from the oven described above, but also as a discharge method in another device.

[0025]

As described above, according to the present invention, falling cans and the like can be automatically detected and discharged without human intervention from cans transferred from a carrying oven or the like. This has the effect of quickly and accurately discharging defective printing cans.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an example of an apparatus for performing a method of the present invention.

FIG. 2 is a side view showing a detection state of an alignment can and a dropping can in the method according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating a method according to a first embodiment of the present invention.

FIG. 4 is a timing chart regarding capture of image data.

FIG. 5 is an explanatory diagram of a state where image data has been binarized.

FIG. 6 is an explanatory diagram illustrating a state where labeling processing is performed on image data.

FIG. 7 is an explanatory diagram of a state after grouping and block division after the labeling process.

FIG. 8 is a flowchart illustrating a method according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Oven 11 Belt 20 (20a, 20b) Video camera 30 Image data processing part 31a, 31b Video camera controller 32 Image capture control part 33a, 33b Image memory 34 Labeling processing part 40 Sequencer 41 Sensor 42 Dropping can sensor 50 Magnet elevator 51 Electromagnet

Claims (4)

(57) [Claims] An image data is obtained by photographing a plurality of cans conveyed in a row with a video camera, and the image data is subjected to a binarization process and a labeling process, and then to a labeling process. The value is compared with the set value to detect a non-defective can, and if the non-defective can is determined to be a falling can, a contact can, or a missing can, it is determined to be a falling can or a contact can A method for discharging falling cans, including discharging the falling cans, contact cans and surrounding cans. 2. A labeling process for binarizing image data.
Processing to obtain a can shadow, and the area of this can shadow and / or the
A process for calculating the length in eight directions from the center of the area
1. The method for discharging fallen cans and the like according to 1. 3. The method according to claim 1, further comprising the step of determining whether the part determined to be a missing can is in a state where the can is actually removed or in a state where a falling can exists. How to discharge cans, etc. 4. A row of cans including a portion determined to be a missing can by judging whether the portion determined to be a missing can is in a state where the can is actually removed or a state where a falling can exists. To
4. The method for discharging fallen cans and the like according to claim 3, wherein the method is performed depending on whether or not the cans have fallen when the cans are transferred to the magnet conveyor.