JPH05322630A - Level detector in can - Google Patents

Abstract

PURPOSE:To realize accurate detection of content regardless of the liquid level in a can by irradiating the vicinity of liquid level in a can, being transferred continuously to be detected, two-dimensionally with X-ray and then operating an average level line of multiple level lines obtained through image processing. CONSTITUTION:An X-ray irradiating means 120 irradiates substantially the entirety including the vicinity of liquid level in a can 110, two-dimensionally with X-ray. Consequently, a photographing means 122(comprising an X-ray visible panel 130 and a CCD camera 131) photographs an X-ray transmissive image of substantially the entirety of the can 110. The photograph results are temporarily stored in a memory 132 and displayed 136, while at the same time the photograph results are subjected to differentiation with respect to gradation at a differentiating section 134 in order to detect the upper end part and the liquid level 118 of the can 110. A decision means 126 operates an average liquid level in the can 110 based on a plurality of data obtained from the differentiating section 134 and then makes a decision whether the liquid level 118 is within an appropriate range based on the difference between the upper end of can cover tightened part 140 and the average liquid level. Output from the decision means 126 is delivered to a removing means 138 which subsequently removes a can of inappropriate content from the line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-can liquid level detecting device, and more particularly to improvement of an in-can liquid level detecting device using X-rays.

[0002]

2. Description of the Related Art As a device for inspecting the content of various cans, an in-can liquid level detecting device using X-rays is widely used because of its quick response.

That is, the conventional liquid level detecting device in a can is
The X-ray irradiating means is arranged on one side of the inspected cans that are continuously conveyed, and the X-ray light-receiving diode array is arranged on the other side of the cans in the vertical direction. The line position and the X-ray position passing through the head space in the can are respectively detected to determine the suitability of the liquid surface level (Japanese Patent Laid-Open No. 235032/62, 5958/1982).
No. 0).

[0004]

However, it has been clarified that the conventional liquid level detecting device for an internal can using X-rays has a problem in detection performance.

That is, as shown in FIG. 4, by using X-rays 14 which penetrate the upper limit position of the liquid level 18 in the can 10 moving in the direction of arrow 12 and X-rays 16 which penetrate the lower limit position of the liquid level. When performing liquid level suitability determination, there are few problems as long as the liquid level 18 is in a stable state, but as shown in FIG. 5, due to vibration, inclination or slight speed change of the belt conveyor that conveys the can 10, When the surface 18 is inclined or disturbed, it is determined that the amount of the X-rays 14 and 16 is too high, or the amount of the amount of the X-rays 14 and 16 is too high, although the can is originally a normal amount. It may be judged.

In order to avoid such a situation, it is necessary to carry the can 10 in an extremely stable state.
While the transport control is difficult, it eliminates erroneous detection that is judged to be unsuitable even though the amount of flavor is appropriate, or that it is appropriate even if the amount of flavor is inappropriate as described above. I couldn't.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide an in-can liquid level detection device capable of performing accurate content inspection while using X-rays having excellent responsiveness. To provide.

[0008]

In order to achieve the above object, a device for detecting a liquid level in a can according to the present invention is arranged at one side of an inspected can that is continuously conveyed, and at least the inspected can. X-ray irradiating means for irradiating X-rays in the vicinity of the liquid surface in the inside thereof, and an image of the X-ray irradiating surface of the X-ray irradiating means, which is arranged to face the X-ray irradiating means with the inspected can sandwiched therebetween. The image processing means for performing the image processing means, the image processing means for processing the image data from the image capturing means and detecting the liquid level in the inspected can, and the average value of the many liquid level lines obtained by the image processing means. It is characterized in that it comprises a determination means for determining whether or not a certain average line is at a predetermined position.

In the present invention, it is preferable that the image pickup means is composed of an X-ray visualization panel and a CCD camera so that the X-rays transmitted through the can are visualized and imaged by the CCD camera.

[0010]

As described above, the device of the present invention detects a large number of liquid level lines in the can to be inspected, and judges the suitability of the liquid level in the can from the average line of the liquid level lines (that is, the average liquid level height). Therefore, for example, even if the liquid level in the can is disturbed or tilted, the liquid level line itself will change, but the average liquid level line will accurately reflect the amount of the canned taste, and the inside of the can will be extremely accurate. The liquid level can be detected.

Further, by visualizing the X-rays transmitted through the can and then capturing the image with a CCD camera, high-speed processing of the can inspection becomes possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of the apparatus of this embodiment.

The in-can liquid level detecting device 100 shown in FIG.
The X-ray irradiation means 120, the imaging means 122, the image processing means 124, and the determination means 126 are provided, and the belt conveyor 12 is provided between the X-ray irradiation means 120 and the imaging means 122.
The can 110 conveyed by 8 in the direction orthogonal to the drawing is positioned.

The image pickup means 122 is composed of an X-ray visualization panel 130 arranged to face the X-ray irradiation means 120 with the can 110 interposed therebetween, and a CCD camera 131 for taking an image of the X-ray visualization panel 130 from the back side. Configured by this,
Obtaining an X-ray image.

That is, the X-ray irradiation means 120 is the can 110.
The X-rays are radiated planarly over almost the entire surface including the vicinity of the liquid surface, and as a result, the imaging means 122 captures an X-ray transmission image over the almost entire area of the can 110.

The image processing means 124 is a frame memory 1.
32 and a differential processing unit 134, the shooting result by the image pickup unit 122 is temporarily stored in the frame memory 132, the shooting result is displayed on the display 136, and the differential processing unit 134 performs the differential calculation of the grayscale change. Then, the upper end of the can 110 and the liquid surface are detected.

The judging means 126 calculates the average liquid level of the can 110 from a plurality of liquid level data obtained from the differentiating part 134, and calculates the upper end of the can 110 (the upper end of the can lid winding part) and the average liquid level line. It is determined whether the liquid surface is within the proper range from the difference value of.

The output of the judging means 126 is instructed to the excluding means 138, and for the cans having an unsuitable content, an arm (not shown) arranged on the belt conveyor 128.
Remove it from the line by driving.

FIG. 2 shows a data processing step in the present invention.

As described above, the X-ray irradiating means 120 irradiates the entire can 110 with X-rays, and the X-ray visualization panel 130 visualizes the X-ray transmission image over substantially the entire can 110. Then, the CCD camera 131 photographs the X-ray visualization panel 130, and the image data thereof is stored in the frame memory 132 in a 90-degree inverted state as shown in FIG. This image data is scanned in the x direction in the figure, and for example, the brightness of the nth scanning line becomes as shown in FIG.

That is, the lightness (transmitted X-ray intensity) I is the maximum when the can 110 is not present, and
It greatly decreases in the winding portion 140, slightly increases in the head space portion 141, and decreases again in the portion 142 where the liquid exists.

As a result, the lightness I as shown in FIG.
Is differentiated, a peak 144 due to an extremely large change in brightness is recognized at the upper end of the can 110, and immediately after that, a peak 145 at the boundary between the tightening portion 140 and the headspace portion 141 appears, and then the liquid level is further increased. A peak 146 based on the change in brightness due to is detected. Therefore, the gap (D ₁ + D ₂ ) between the two peaks 144 and 146 indicates the distance of the head space portion 141, that is, the amount of flavor of the can 110. Here, since the image may be disturbed near the peaks 144 and 145, the peak 14 is generated in this embodiment.
The peak after passing about 5 mm (D ₁ ) from 4 was detected, and the peak 146 was determined to be the liquid surface.

The scanning in the x direction is repeated, and the liquid level line 118 in the can 110 is detected each time.

A large number of liquid surface lines 11 thus obtained
The average value of 8 is obtained, and the amount of flavor in the can 110 is determined from the average liquid level line.

Therefore, for example, as shown in FIG.
Even when 18 is detected tilted, the average liquid level line 15
By calculating 0, it is possible to always perform an accurate content inspection regardless of the liquid surface state.

As in this example, when the X-rays are visualized by the X-ray visualization panel (I / I panel) and then imaged by using a CCD camera having good response, the liquid level in the can can be inspected at an extremely high speed. A device is possible.

[0028]

As described above, according to the liquid level detecting device in a can according to the present invention, an image near the liquid level of the inspected can is processed by X-rays, and a large number of liquids detected by the image processing are processed. Since the average liquid level line is calculated from the surface line and the amount of soaking is detected from the average liquid level line, it is possible to perform an accurate soaking amount inspection regardless of the liquid level state in the can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an image processing state by the in-can liquid level detection device shown in FIG.

FIG. 3 is an explanatory diagram of an image processing state by the in-can liquid level detection device shown in FIG. 1.

FIG. 4 is a schematic explanatory view of a conventional liquid level detection mechanism in a can.

FIG. 5 is a schematic explanatory view of another conventional liquid level detection mechanism in a can.

[Explanation of symbols]

 110 ... Inspected can 118 ... In-can liquid level 120 ... X-ray irradiation means 122 ... Imaging means 124 ... Image processing means 126 ... Judgment means 130 ... X-ray visualization panel 150 ... Average liquid level line

Claims (2)

[Claims] 1. An X-ray irradiating device which is arranged on one side of a continuously conveyed inspected can and irradiates at least the liquid surface in the inspected can with X-rays in a planar manner, and the inspected object. Sandwich the can
An image pickup unit which is arranged so as to face the X-ray irradiation unit and which picks up an image of the X-ray irradiation surface of the X-ray irradiation unit, and image data from the image pickup unit is processed to detect the liquid level in the inspected can. An in-can liquid comprising image processing means and determination means for determining whether or not an average line, which is an average value of a large number of liquid surface lines obtained by the image processing means, is at a predetermined position. Surface detection device. 2. The in-can liquid level detecting device according to claim 1, wherein the image pickup means comprises an X-ray visualization panel and a CCD camera.