JPH01202241A - Method for detecting residual shell in shucked shellfish and apparatus therefor - Google Patents

Abstract

PURPOSE:To contrive automatic discrimination between pieces of shells and shucked shellfishes, by measuring intensity and wave form of an absorption part and absorption width of an absorption signal in an X-ray image and discriminating the X-ray absorption parts due to the pieces of the shell and shucked shellfishes based on the measured values. CONSTITUTION:X-rays are irradiated to shucked shellfishes 14 in the respective buckets 24 on a bucket conveyor 18 in an X-ray irradiator 32. An X-ray image of the shucked shellfishes 14 is received by an X-fluorescent plate 36 emitting light by sensitizing to the X-rays of a receptor having the fluorescent plate 36. Further, the light emitted from the fluorescent plate 36 is converted into an electric signal by a photoelectric transfer element 38. The electric signal of the photoelectric transfer element 38 is amplified to a prescribed level in a signal processor 40 and then subjected to logarithmic conversion to measure the intensity, width and absorption wave form of an X-ray image absorption part of the above-mentioned transferred image signal. Thereby, X-ray image absorption parts of the shucked shellfishes and pieces of shells are discriminated based on the afore-mentioned measured values. Furthermore, a control signal is taken from the processor 40 in a selector 59 to operate the bucket 24 and remove the shucked shellfishes containing pieces of shells.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and apparatus for detecting shell fragments or foreign substances remaining in a shellfish, and particularly to a method and apparatus for detecting shell fragments or foreign substances remaining in a shellfish. The present invention relates to a method and device for detecting remaining shells.

[Prior art]

To detect residual grains in peeled shellfish, the shellfish is boiled, then peeled, the boiled juice is separated, and then put into a water tank to separate coarse grains. Visual inspection is conducted above to separate and remove them.

FIG. 15 is an explanatory diagram showing a conventional method of detecting residual grains during peeling and scavenging by visual inspection. As shown in Figure 15, the clams after boiling are placed in a step-shaped water tank 70.7.
The remaining grains are sequentially introduced into and transferred to a mesh belt conveyor 72 after separating coarse grain residues. On the belt conveyor 72, residual grains during peeling are detected by an inspector's visual inspection, and in the next step, a search coil type metal detector 74 automatically detects metal foreign objects. However, in such a visual inspection, it is not possible to visually confirm the remaining grains that are stuck inside the peeled shells or caught inward by clams, and as the fatigue of the inspector increases, there is a risk that many things will be overlooked. Furthermore, since the clams are exposed to the air on the mesh belt conveyor 72, there is a possibility that the taste of the clams may deteriorate. Therefore, in contrast to such a method of detecting remaining clam shells by visual inspection, automatic detection methods using equipment have been considered, and the equipment detection methods include an ultrasonic detection method, an electromagnetic inspection method, and a soft X-ray method.

[Problem that the invention seeks to solve]

However, such automatic detection methods have various problems. The problem with the ultrasonic detection method is that it cannot easily distinguish between clams and leftovers. It is difficult for electromagnetic inspection methods to detect foreign substances other than metals. For example, non-magnetic metals have a poor detection accuracy (N/S), making it difficult to apply them.

Furthermore, since soft X-ray inspection equipment can recognize various foreign substances, it has a great track record in detecting foreign substances in foods other than shellfish. However, there is no device to visually judge the X-ray television camera images of clams being transported on a mesh-type belt conveyor, and automation of this judgment has been delayed. The reason for this is that the difference in X-ray absorption between the scraps and the shelled clams is not large, so signal processing is difficult, and there is no effective method for separating the scraps and the shelled clams.

The present invention was made in view of the above circumstances, and provides a method and apparatus for detecting remaining shells in shelled shells, which increases the detection sensitivity of the difference in X-ray absorption between shelled shells and shelled clams through signal processing, and enables automatic discrimination. The purpose is to make suggestions.

[Means for solving problems]

In order to achieve the above object, the present invention provides a method for detecting shell fragments remaining in a shellfish, in which the shellfish is irradiated with X-rays, and the shellfish is exposed to X-rays. The X-ray image is received through an X-ray fluorescent screen and converted into an electric signal, the electric signal is amplified to a predetermined level and then logarithmically converted, and the intensity of the X-ray image absorption part of the logarithmically converted X-ray image signal, The width and absorption waveform are measured, and based on the measured values, the X-ray image absorbing part of the peeled shellfish and the X-ray image absorbing part of the shell piece are discriminated, and based on the discrimination, the sorting device is controlled to remove the shells. It is characterized by separating and removing shellfish including pieces.

Further, according to the present invention, in a device for detecting remaining shells in peeled shellfish for detecting shell fragments remaining in peeled shellfish, packets are arranged side by side, and the packets are intermittently transferred at a constant cycle, and A packet conveyor that continuously puts a predetermined amount of shellfish into each packet, an X-ray irradiation device that irradiates X-rays toward the shellfish in the packet, and an X-ray fluorescent plate that emits light when exposed to X-rays. a light receiving device that receives an X-ray image of the peeled shellfish with the fluorescent screen; a photoelectric conversion element that converts the light emitted from the X-ray fluorescent screen of the light receiving device into an electric signal; and a photoelectric conversion element that converts the electric signal of the photoelectric conversion element into a predetermined After amplification to a level of a signal processing device for discriminating the X-ray image absorbing portion from the X-ray image absorbing portion; and a sorting device that receives a control signal based on the discrimination from the signal processing device and operates the bucket of the conhair to separate and remove shucked shellfish including shell fragments. It is characterized by being composed of.

[Effect]

According to the method and device for detecting remaining shells in peeled clams according to the present invention, X-ray transmitted images of shell pieces and peeled clams are captured by a highly sensitive X-ray fluorescent screen, and the emitted light is electrically converted using a photoelectric conversion element. The electric signal is converted and amplified to a predetermined level by a signal processing device, and the signal is subjected to logarithmic conversion processing to remove noise accompanying the amplification and quantum noise inherent in the signal. In order to distinguish the X-ray image absorption areas of shell fragments and peeled clams that have undergone signal processing in this way, it is necessary to determine the intensity of the absorption area from the average base level, the width of the absorption area at a constant value, and the absorption area. This is done by finding the waveform.

Therefore, it is possible to automatically discriminate between shell pieces and peeled shellfish, and the sorting device can accurately sort the shell pieces based on the discrimination signal.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method and apparatus for detecting remaining shells in peeled shellfish according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram of a device for detecting remaining shells in peeled shellfish according to the present invention. As shown in FIGS. 1 and 2, a supply hopper 16 for supplying peeled clams 14 is provided on the right side of the main body 12 of the apparatus 10 for detecting remaining shells in peeled clams. A conveyor 18 is provided within the body 12, and the conveyor 18 includes a plurality of rollers 20.2.
0..., a chain 22 that revolves between each roller 20, buckets 24, 24... that are attached to the chain 22 like a piano keyboard, and a belt 26 that connects the drive roller 2OA.
It is composed of a motor 28 that rotates the motor 28 via a motor 28.

This motor 28 is connected to a power supply/control box 30 and rotated intermittently. Therefore, the bucket 24 is intermittently transferred;
The peeled clams 14 supplied from the hopper 16 are placed in the bucket 2.
A predetermined amount is added to 4 and transferred intermittently.

An X-ray irradiation device 32 is attached to the ceiling surface at approximately the center of the main body 12 of the device 10 for detecting remaining shells in peeled shellfish, and the XVA irradiation device 32 is housed in a shield room 34. This X
The vA irradiation device 32 is connected to the power supply/control box 30 and irradiates the conveyed peeled clams 14 in the bucket 24 with low X-ray intensity (60 to 80 KV, 3 to 5 mA).

Moreover, the ripple frequency of this X-ray is 300Hz.

As shown in FIG. 3, the X-rays transmitted through the peeled clam 14 are received by the X-ray fluorescent screen 36 of the light receiving device. The X-ray fluorescent screen 36 is made of a rare earth phosphor, and a voltage of 350 VDC is applied to both sides of the phosphor. This X-ray fluorescent screen 36 has the characteristic of displaying an X-ray image with high sensitivity and high brightness by electroluminescence. Also, at this time,
The voltage accumulation time of the X-ray fluorescent screen 36 is set in synchronization with the ripple frequency of the ray irradiation device 32. This results in
The X-ray fluorescent screen 36 rounds off the periodic fluctuations of X-rays and improves the S/N through integral accumulation.

A photoelectric conversion element 38 that photoelectrically converts the light emitted from the X-ray fluorescent plate 36 into an electric signal is closely attached to the X-ray fluorescent plate 36, and the photoelectric conversion element 38 is composed of a close-contact image sensor (35 pixels, photodiode array). This electrical signal is sampled by the signal processing device 40.

The pulse generator 42 of the signal processing device 40 outputs a clock signal and a capture start signal to the controller 44 (see (11, (2) in FIG. 4).
4 outputs a signal to a driver 46 based on the start signal, and the driver 46 outputs an address signal and a control signal to a multiplexer 48. Sampling of the electrical signal from the photoelectric conversion element 40 is started by the multiplexer 42 in the signal processing device 40 in synchronization with the ripple frequency (300 Hz) of the irradiated X-ray, and the electric signal is transferred to the photoelectric conversion element 38.
are sequentially switched and read from a one-dimensional array (see (3) and (4) in FIG. 4). This results in 1
An X-ray image absorption level signal A of approximately 20 mV is obtained within the word processing section 42 .

This X-ray absorption level signal A is amplified ten times by a video operational amplifier 50 in the signal processing device 40 and output to an A/D converter 52. The A/D converter 52 samples and holds the input video signal based on the trigger signal from the controller 44, converts it into a local continuous signal, and converts it into a digital signal by the 12-bit A/D converter 52. .

In this case, in order to remove switching noise of the X-ray image electrical signal read out from the one-dimensional array of photoelectric conversion elements 40, the A/D conversion of the electrical signal is performed using the reading clock of the photoelectric conversion element 40 of the one-dimensional array. (100 KHz) via the controller 44 (see (7) shown in FIG. 4). As a result, noise accompanying amplification and quantum noise inherent in the signal are effectively removed, and even if the difference in X-ray absorption between peeled clams and leftover grains is small, subsequent signal discrimination processing becomes easy.

The signal from A/D converter 52 is then sent via DMA interface 54 to a 16-bit personal computer 56 for data processing.

FIGS. 5(A) to 5(D) show the personal computer 5
CRT at various stages where the original signal was corrected by 6
It is an image diagram.

FIG. 5(A) is based on the original signal from the A/D converter 52.
FIG. 5 CB) is an X-ray image absorption waveform diagram obtained by applying logarithmic conversion correction (ielog V) to the original signal. Figure 5 (
C) is an X-ray image absorption waveform diagram on a CRT screen obtained by gain-correcting the logarithmically converted signal, and FIG. personal computer 5
6 analyzes the trap (X-ray absorption part) of the X-ray image absorption waveform based on the shading-corrected signal of FIG. 5(D) (see FIG. 6). The computer 56 calculates the depth of the trap from the average base level of X-ray absorption (X-ray absorption intensity), the width of the trap at a value lowered by a certain value from the average base level, the waveform of the trap, and the integral value of the trap (area value). is measured, and based on the measured value, it is processed to distinguish between traps caused by peeled clams and traps caused by leftover grains or other foreign substances, and control signals based on the discrimination processing are generated as shown in Figure 1 and Part 2. It is output to a subsequent sorting device 59.

As shown in FIGS. 7 and 8, an arm 60 is attached to the chain 22 of the conveyor 18, and one end of the packet 24 is rotatably attached to the tip of the arm 60 via a pivot pin 62. The other end of the packet 24 is a support roller 64
Supported by

The support roller 64 in the sorting device 59 is movable in the direction of arrow A, as shown in FIG. Ru. As shown in FIG. 1, a hopper 66 for non-defective products and a hopper 68 for defective products are provided below the support rollers 64, 64, . . . of the sorting device 59.

Therefore, by operating the support rollers 64, 64, .
6 or dropped into a hopper 68 for defective products.

The support rollers 64, 64 of the sorting device 59 are operated based on control signals from the computer 56 of the signal processing device 40, and the packets 24 containing leftover grains or foreign matter are positioned on the support rollers 64 above the defective product hopper 68. At that time, the support roller 64 is controlled? Arrow A shown in FIG. 8 by the In signal
move in the direction of Further, when the bucket 24 of the peeled clams 14 with no foreign matter remaining is positioned on the support roller 66 above the good product hopper 66, the support roller 66 moves in the direction of arrow A shown in FIG.

A shielding box 69 is formed within the inspection area of the packet conveyor 18 in the main body 12 of the remaining shell detection device during peeled clams 14, and the box 69 prevents X-rays from diffusing to the outside.

According to the method and apparatus for detecting remaining shells in peeled shellfish according to the present invention configured as described above, the peeled clams 14 fed from the supply hopper 16 are continuously fed into the bucket 24 in predetermined amounts, and exposed to X-rays. It is intermittently transferred under the device 32. The peeled clams 14 in the packet 24 are irradiated with X-rays by the X-ray irradiation device 32 in synchronization with the intermittent transfer cycle of the con hair 18. The X-ray transmitted image of the peeled clam is received by the X-ray fluorescent screen 36. The light emitted from the X-ray fluorescent screen 36 is transmitted by the photoelectric conversion element 3
8 into an electrical signal, and the electrical signal is taken into the signal processing device 40.

The signal processing device 40 takes in the electrical signal from the photoelectric conversion element 38 at a constant timing, amplifies the X-ray image level signal A with an operational amplifier 50, and converts it into digital data with an A/D converter 52. The X-ray image processing signal converted into a digital signal is output to the personal computer 56, and the personal computer 56 performs logarithmic conversion correction processing on the X-ray image processing signal to eliminate noise caused by the amplification of the operational amplifier 50 and the A/D converter 52, and to remove the original signal. Quantum noise is removed.

As a result, the corrected X-ray image signal shows clear absorption areas for the ff111 clams 14 and the remaining grains.

Figures 9(A) to 12(A) are side views showing the state of peeled clams and leftover grains at the time of photographing, and Figures 9(B) to 12
Figure (B) is an X-ray absorption waveform diagram showing the X-ray image signal at that time. The X-ray waveform absorption image has been subjected to gain correction and shading correction in addition to logarithmic conversion processing correction. 9th
As is clear from Figures 1 and 2, peeled clams 1
4 and residue 15 are clearly detected, and their X-ray absorption values can be printed from the computer 56. In addition, the depth (X-ray absorption intensity), width, waveform, and total area of these detection traps are measured, and based on the measurements, it is determined whether the traps are separated by scavenging 14, leftover grains 15, or other traps. It is processed to distinguish between traps caused by foreign objects. For this reason, 14 shelled clams and 15 leftovers were prepared.
The discrimination between the two is made clear and automatic discrimination is possible.

Based on the discrimination processing of the personal computer 56, a control signal is output to the sorting device 59, and the sorting device 59, based on this control signal, removes the conveyor 24 containing shell pieces or foreign matter by the action of the support rollers 64. The shelled clams 14 that are rotated down in a keyboard manner and contain grain residue or foreign matter can easily accumulate in the defective hopper 68 and be separated. Therefore, the remaining shelled clams 14 can be detected by a detection method using X-rays. Grain residue can be automatically detected and separated.

FIGS. 13 and 14 are a plan view and a side view of a second embodiment of the method and apparatus for detecting remaining shells in peeled shellfish according to the present invention. As shown in FIGS. 13 and 14, the supply hopper 16, X-ray irradiation device 32, X-ray fluorescent screen 36, and signal processing device 40 of the method and apparatus 71 for detecting remaining shells in peeled shellfish are shown in FIG. The structure is substantially the same as that of the device of the first embodiment, and detailed explanation thereof will be omitted.

The device 71 for detecting remaining shells in a shellfish according to the second embodiment is characterized by a packet conveyor 73, and a substantially fan-shaped packet 7 is arranged around a rotary plate 75 of the bucket conveyor 73.
7,77... are disposed, one end of which is rotatably supported, and support rollers 64, 64... are disposed at the other end outside the packets 77,77.... The rotary plate 75 is intermittently rotated by the motor 28, and at the same time the packet 7
7 is also transferred intermittently. In addition, the support roller 6 of the sorting device 59
4 is operated to move outward of the rotating plate 75 (arrow E or F shown in FIG. 13) based on a control signal from the signal processing device 40, so that the packet 77 is rotated downward.

Even in such a structure, the packet 77 of the shellfish 14 containing shell pieces and foreign objects can be easily manipulated, similar to the method and apparatus for detecting shells remaining in shellfish shown in FIGS. 1 and 2. can be easily separated.

〔Effect of the invention〕

As explained above, according to the method and device for detecting remaining shells in peeled shellfish according to the present invention, an X-ray transmission image is converted into an electrical signal by a photoelectric conversion element, and the X-ray image level signal is converted by a signal processing device. The intensity of the absorption part of the XvA image absorption waveform signal is amplified to a predetermined level, and subjected to logarithmic conversion processing correction.
The absorption width and the wave shape of the absorption part were measured, and based on these measurement values, the X-ray absorption part of the shell piece and the X-ray absorption part of the shellfish were distinguished. The detection sensitivity of line absorption differences is increased and automatic discrimination is possible.

[Brief explanation of the drawing]

FIG. 1 is a device for detecting remaining shells in peeled shellfish according to the present invention.FIG. 2 is a side view of FIG. 1, and FIG. Explanatory diagram, Fig. 4 is a timing diagram in the signal processing device, and Fig. 5 is CR at various stages when the original signal is corrected by a personal computer.
Figure 6 is an X-ray image absorption waveform diagram based on a T-image;
Figures 9 and 8 are side views showing the bucket mounting structure;
Figures 9 to 12 are side views and X-ray image absorption waveform diagrams showing the time of photographing detached shellfish and shell fragments, and Figures 9(A) to 12(A) are side views during photographing; FIGS. 9(B) to 12(B) are X-ray image absorption waveform diagrams, and FIGS. 13 and 14 are plan views of a second embodiment of the apparatus for detecting remaining shells in peeled shellfish according to the present invention. and a side view, and FIG. 15 is an explanatory diagram of a conventional method for detecting tension shells in peeled shellfish. 10.71...Method and device for detecting tension shells in peeled shellfish, 1
2... Main body, 14... Stripped clam, 15...
・Remaining grains, 18.73...Bucket conhair, 2
0...Roller, 22...Chain, 24.
68... Bucket, 28... Morph, 32
...X-ray irradiation device, 36...X-ray fluorescent screen, 38.
...Photoelectric conversion element, 40...Signal processing device, 42.
...Pulse generator, 44...Controller,
48... Multiplexer, 50... Video operational amplifier, 52... A/D converter, 56... Personal computer, 59... Sorting device, 64...
・Support roller, 66...Good product hopper, 68...
Defective product hopper.

Claims (2)

[Claims] (1) In a method for detecting shell fragments remaining in a shellfish, the shellfish is irradiated with X-rays, and the X-ray image of the shellfish is displayed on an X-ray fluorescent screen. , and converts the electrical signal into an electrical signal, amplifies the electrical signal to a predetermined level, performs logarithmic conversion, and measures the intensity, width, and absorption waveform of the X-ray image absorption part of the logarithmically converted X-ray image signal. , distinguishing between the X-ray image absorbing part of the peeled shellfish and the X-ray image absorbing part of the shell piece based on the measured value,
A method for detecting remaining shells in shellfish, comprising controlling a sorting device based on the discrimination to separate and remove shellfish including shell fragments. (2) In the device for detecting shell fragments remaining in peeled shellfish, buckets are arranged in parallel, and the buckets are intermittently transferred at a certain period, and each peeled shellfish is A bucket conveyor that continuously feeds a predetermined amount into a bucket, an X-ray irradiation device that irradiates X-rays toward the shellfish in the bucket, and an X-ray fluorescent screen that emits light when exposed to X-rays, the fluorescent screen a light receiving device that receives an X-ray image of the peeled shellfish; a photoelectric conversion element that converts the light emitted from the X-ray fluorescent screen of the light receiving device into an electrical signal; and a photoelectric conversion element that amplifies the electrical signal of the photoelectric conversion element to a predetermined level. Afterwards, logarithmic conversion is performed to measure the intensity, width, and absorption waveform of the X-ray image absorption part of the converted image signal, and based on the measured values, an X-ray image of the X-ray image absorption part of the peeled shellfish and an X-ray image of the shell piece is obtained. and a sorting device that takes in a control signal based on the discrimination from the signal processing device and separates and removes shellfish including shell pieces by operating the bucket of the conveyor. This is a unique feature of the device for detecting remaining shells in peeled shellfish.