JP3737929B2 - X-ray foreign object detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, X-rays are emitted from the X-ray generation unit to the inspection object conveyed from the carry-in entrance, the X-ray transmission amount is detected by the X-ray detection unit, and the inspection object is carried out from the carry-out port. In particular, the present invention relates to an X-ray foreign object detection device that prevents exposure of a human body to X-rays.
[0002]
[Prior art]
15 and 16 show an X-ray foreign object detection device 50. FIG. The X-ray foreign object detection device 50 includes a foreign object detection unit 51 that detects a foreign object from the inspection object W, and a transport mechanism 54 that transports the inspection object W. Conveying mechanism 54, and the conveyor belt B and four transport rollers 55 consist of a driving motor (not shown) to convey the test objects W loaded from the loading port R _in, so as to unload the unloading port R _out Yes.
[0003]
The foreign object detection unit 51 includes an X-ray generator 52 supported by a support plate 56 at the upper part of the apparatus and an X-ray detector 53 provided in the middle part of the apparatus. On the lower surface of the X-ray generator 52, an X-ray spray port 52 a that bombards the X-ray toward the X-ray detector 53 in a substantially conical shape is provided, and a long hole formed in the support plate 56. A substantially triangular screen-shaped X-ray is exposed through the shaped slit.
[0004]
The X-ray detector 53 is provided in a metal box 57 disposed in a space where the back surface of the conveyor belt B faces. The back surface of the conveyor belt B is in sliding contact with the upper surface of the metal box 57.
[0005]
The inspection object W on the conveyor belt B passes through a screen-shaped X-ray screen from the X-ray generator 52. When passing through the screen, the X-ray exposure amount that passes through the inspection object W is detected by the X-ray detector 53, and it is detected whether or not foreign matter is mixed in the inspection object W.
[0006]
Since X-rays adversely affect the human body, the exposed X-rays are repeatedly reflected and attenuated by the conveyance path R including the back surface of the support plate 56, the inner side surface of the center of the apparatus, and the conveyance belt B. The X-rays emitted from the carry- _in port R _in and the carry-out port R _out do not affect the human body. Further, a rubber shielding curtain 58 is provided on the back surface of the support plate 56 to shield X-rays.
[0007]
[Problems to be solved by the invention]
However, since the X-ray foreign object detection device 50 constitutes a part of the conveyance line of the inspection object W, if the inspection object W is clogged in the middle of the conveyance path, the exposure of the X-ray is caused by carelessness of the operator. There is a case where a user tries to take out the inspection object W from the carry- _in entrance R _in or the carry-out exit R _out without stopping the shooting. For this reason, X-rays are directly exposed to the human body.
[0008]
In particular, when a food item is detected as an object W to be inspected, the conveyed food item comes into contact with the shielding curtain 58. Therefore, the shielding curtain 58 is removed and inspected due to hygiene problems. . In this case, when a human body enters the transport path R due to carelessness as described above, a larger amount of X-rays is exposed as compared with the case where the shielding curtain 58 is present.
[0009]
The present invention has been made in order to eliminate the above-mentioned disadvantages of the prior art. The object of the present invention is to detect X-ray exposure from the X-ray generation unit by detecting the intrusion of the human body into the conveyance path. The aim is to control the radiation dose and to ensure the safety of the human body from X-ray exposure.
[0010]
[Means for Solving the Problems]
In short, the X-ray foreign matter detection apparatus according to claim 1 of the present invention irradiates the inspection object (W) conveyed from the carry- _in entrance (R _in ) with X-rays from the X-ray generation unit (2). In the X-ray foreign object detection device that detects the X-ray transmission amount by the X-ray detection unit (53) and _{carries out the} inspection object from the carry-out port (R _out ),
A pair of facing light projecting / receiving elements (4a, 4b) and the carry-in port or / and the carry-out port are set as a monitoring region, and a preset setting passage corresponding to a time during which the inspection object passes through the monitoring region. Time measuring means (7) for measuring the time (t ₀ ) from the time when the light receiving level of the light receiving element is lowered from a predetermined level, and detecting the presence or absence of an object passing through the monitoring area, Discrimination means (3) for discriminating whether or not the detected object is a human body;
Position adjusting means (11) capable of adjusting the pair of light emitting / receiving elements in the height direction;
And a control means (10) for controlling the X-ray exposure dose exposed from the X-ray generation unit to be less than a predetermined amount when the determination means determines that the object is the human body. ,
The discriminating means discriminates the object passing through the monitoring area as the human body when the light receiving level of the light receiving element after the set passage time has passed is the low level, and the passage after the set passage time has passed. When the light receiving level of the light receiving element is the predetermined level, the object passing through the monitoring area is determined as the inspection object,
The control means controls the position adjusting means to raise the position of the pair of light projecting / receiving elements when the discrimination means discriminates the object as the inspection object .
[0011]
Moreover, the X-ray foreign object detection apparatus according to claim 2 of the present invention is the X-ray foreign object detection apparatus according to claim 1,
The control means, after the X-ray exposure amount is controlled to be less than the predetermined amount , based on the detection signal from the detection means , when it is detected that there is no object determined to be the human body, Controlling the X-ray exposure amount to be greater than or equal to the predetermined amount, and the control means controlling the alarm means to generate an alarm sound when the discrimination means determines that the object is the human body. Features.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, a first embodiment of an X-ray foreign object detection device according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the part same as a prior art, and the description is abbreviate | omitted.
[0013]
FIG. 1 is a schematic block diagram showing a first embodiment of an X-ray foreign object detection device 1 according to the present invention. The X-ray foreign object detection device 1 according to the first embodiment is roughly composed of an X-ray generation unit 2, a determination unit 3, and a control unit 10.
[0014]
The X-ray generator 2 is provided with an X-ray generator 52. Normally, a predetermined amount of X-rays are always applied to the lower conveyor belt B by turning on the input switch while the apparatus main body is supplied with power. The screen is exposed to a screen through a slit. The X-ray generator 2 is provided with a switching circuit 2a, and the switching circuit 2a is ON / OFF controlled by a control signal from the control means 10 described later, and accordingly, the X-ray exposure by the X-ray generator 52 is performed. Shooting is ON / OFF controlled.
[0015]
Discriminating means 3, a pair of light emitting and receiving elements 4 (4a, 4b) facing each other have, as shown in FIGS. 2 and 3, the conveyance path R at both ends in inlet port R _in are formed or It is provided on the inner surface 5 of the carry-out port _Rout and serves as a monitoring area.
[0016]
Light emitting and receiving element 4, as shown in FIG. 3 constantly monitors the object passing through the entrance R _in or carry-out port R _out to deliver light toward the light receiving element 4b of the light projecting element 4a, A detection signal (voltage signal) indicating the light reception level of the light receiving element 4b is transmitted.
[0017]
The discriminating means 3 is provided with a discriminating section 6 that discriminates whether or not the object that has passed through the monitoring region upon receiving the detection signal from the light receiving element 4b is a human body. The discriminating unit 6 is provided with a timer 7 as a time measuring means in which an operation time is set in advance. As shown in FIG. 4, the fall of the light receiving level of the light receiving element ((A) in FIG. 4) is detected. It operates for the time set by detection ((B) in FIG. 4). This set time is a time corresponding to the time during which the inspection object W passes through the monitoring area (hereinafter referred to as “setting passage time t ₀ ”), and the transfer speed of the transfer mechanism 54 and the transfer direction of the inspection object W are determined. It is determined in advance from the length.
[0018]
The discriminating unit 6 discriminates whether the object that has passed through the monitoring area is a human body or the inspection object W based on the light reception level after the set passage time t _{0 has} elapsed. Specifically, as shown in FIG. 4, when the light reception level has returned to the original level ((C) in FIG. 4), the passed object is determined as the inspection object, and the light reception level falls. If it remains (maintenance at low level) ((D) in FIG. 4), it is determined as a human body and a determination signal is sent to the control means 10.
[0019]
The control unit 10 receives a determination signal from the determination unit 3 (determination unit 6), and sends a control signal for turning off the power supply to the X-ray generation unit 2 to the switching circuit 2a of the X-ray generation unit 2. Thereafter, when the rising of the light reception level is detected, a control signal for turning on the power supply to the X-ray generator 2 is sent to the switching circuit 2 a of the X-ray generator 2.
[0020]
Next, the effect | action of this Embodiment is demonstrated using FIG.4 and FIG.5. First, power is supplied to the apparatus main body, the switch SW is input, the inspection object W is conveyed, and X-rays are exposed. At this time, the light projecting beam from the light projecting element 4a is received by the light receiving element 4b and is always in a monitoring state (ST1-No).
[0021]
When the object passes through the monitoring area, the light projecting beam from the light projecting element 4a is shielded, and the light receiving level of the light receiving element 4b is lowered as shown in FIG. 4A (ST1-Yes). The discriminating unit 6 detects the fall of the light reception level at this time, and operates the timer 7 for a set passage time t ₀ as shown in FIG. 4B (ST2).
[0022]
When the light reception level after the set passage time t _{0 has} elapsed is the original level, the passed object is determined as the inspection object W (ST3-No), and it is detected again whether or not the object passes through the monitoring area. (ST1). Then, as shown in FIG. 4 (D), when the light reception level after the set passage time t ₀ has been maintained at a low level, the passed object is determined as a human body, and as shown in FIG. 4 (E). Then, a determination signal is sent to the control means 10 (ST3-Yes).
[0023]
The control means 10 receives the determination signal, sends out a control signal for turning off the switching circuit 2a of the X-ray generation unit 2, and sets the X-ray exposure dose to 0 as shown in FIG. ST4). Thereafter, the determination unit 6 detects whether or not the light reception level has increased to the original level (ST5). When the low level is maintained (ST5-No), the light reception level is continuously monitored. As shown in FIG. 4 (G), when the level has risen to the original level (ST5-Yes), as shown in FIG. To send. The control means 10 receives the determination signal, sends out a control signal for turning on the switching circuit of the X-ray generation section, and returns the X-ray exposure dose to the original as shown in FIG. 4 (I) (ST6). .
[0024]
When continuing the foreign object detection of the inspection object W, the light reception level is detected again and the monitoring is continued (ST7-No). If there is no inspection object W, the power of the apparatus main body is turned off and the inspection is terminated (ST7-Yes).
[0025]
In the above-described embodiment, as shown in FIGS. 6 and 7, the light projecting / receiving element 4 may be provided with a position adjusting means 11 that can be adjusted in the height direction. As shown in FIG. 7, the position adjusting unit 11 includes a long hole 12 that moves the light projecting / receiving element 4 in the vertical direction and a drive unit (not shown) that moves the light projecting / receiving element 4 along the long hole 12. Yes.
[0026]
Then, as shown in FIG. 8, when the discriminating means 3 discriminates the object to be inspected W (ST3-No), the control means 10 drives the position adjusting means 11 as shown in FIG. 4 (J). A position correction signal is sent to the unit (drive driver), the position of the light projecting / receiving element 4 is raised (ST8), and the state of the received light level after the rise is monitored (ST5). Thereby, even if it is a case where the height of the to-be-inspected object W conveyed differs, the position of the light projection / reception element 4 can be made to respond | correspond to the maximum height of the to-be-inspected object W. FIG.
[0027]
Next, a second embodiment of the present invention will be described. As shown in FIG. 9, the present embodiment is an example in which the light projecting / receiving element 4 is previously provided at a position higher than the maximum height h of the inspection object W. That is, since the inspected object W is not detected by the light projecting / receiving element 4, the object detected by the light projecting / receiving element 4 is assumed to be a human body, and a determination signal is immediately sent to the control means 10. It is like that.
[0028]
Next, the effect | action of this Embodiment is demonstrated using FIG.10 and FIG.11. First, the light projecting beam from the light projecting element 4a is received by the light receiving element 4b and is always in a monitoring state (ST9-No). When the object passes through the monitoring area, the light projection beam from the light projecting element is blocked, and the light receiving level of the light receiving element 4b is lowered as shown in FIG. The object that has passed immediately due to this level drop is determined as a human body, and a determination signal is sent to the control means 10 as shown in FIG. 11B (ST9-Yes).
[0029]
In response to the determination signal, the control means 10 sends a control signal for turning off the switching circuit 2a of the X-ray generator 2, and the X-ray exposure dose is set to 0 as shown in FIG. ST10). Thereafter, the determination unit 6 detects whether or not the light reception level has increased to the original level (ST11). As shown in FIG. 11D, when the low level is maintained (ST11-No), the light reception level is continuously monitored. As shown in FIG. 11 (E), when the level has risen to the original level (ST11-Yes), as shown in FIG. To send. The control means 10 receives the discrimination signal, sends out a control signal for turning on the switching circuit of the X-ray generation unit, and returns the X-ray exposure dose to the original as shown in FIG. 11 (G) (ST12). .
[0030]
When continuing the foreign object detection of the inspection object W, the light reception level is detected again and the monitoring is continued (ST13-No). If there is no inspection object W, the power of the apparatus main body is turned off and the inspection is terminated (ST13-Yes).
According to this embodiment, since it is not necessary to determine whether or not it is a human body, it is possible to detect a human body with a simple configuration.
[0031]
Next, a third embodiment will be described. The third embodiment is a reference example of the present invention. In this embodiment, as shown in FIG. 12, an infrared sensor 13 is used as the discriminating means 3. As the infrared sensor 13, a thermal sensor such as a pyroelectric type, a thermal expansion type, a thermocouple type, or a resistance type is used which has an operating temperature of room temperature. For example, when the pyroelectric type is used, when an object passes through the monitoring area, infrared rays emitted from the object are absorbed and the thermal energy is converted into thermoelectric power. In response to the electrical signal proportional to the thermal energy, a discrimination signal is sent to the control means 10.
[0032]
As in the first embodiment, a determination unit 6 is provided, and a threshold value is set in advance. If the level of the electrical signal is equal to or higher than the threshold value, the human body is determined and a determination signal is transmitted. If it is less than the threshold value, it may be determined as the inspection object W.
[0033]
Next, the effect | action of this Embodiment is demonstrated using FIG.13 and FIG.14. First, the infrared sensor 13 is set to a monitoring state (steady state) (ST14-No). When the human body passes through the monitoring area, the infrared ray emitted from the human body is received and thermoelectrically converted into an electric signal, and a transient state is obtained as shown in FIG. With the electrical signal generated at this time, as shown in FIG. 14B, a discrimination signal is immediately sent to the control means (ST14-Yes).
[0034]
In response to the determination signal, the control means 10 sends a control signal for turning off the switching circuit 2a of the X-ray generation unit 2 to reduce the X-ray exposure dose to 0 as shown in FIG. ST15). Thereafter, it is detected whether the element surface of the infrared sensor 13 is in a steady state (ST16). As shown in FIG. 14D, when the transient state is maintained (ST16-No), the infrared light reception level is continuously monitored. As shown in FIG. 14 (E), when returning to the steady state (ST16-Yes), as shown in FIG. 14 (F), a discrimination signal indicating no human body is sent to the control means 10. And the control means 10 sends out the control signal which turns ON the switching circuit 2a of the X-ray generation part 2, and as shown in FIG.14 (G), returns X-ray exposure amount to the original (ST17).
[0035]
When the foreign object detection of the inspection object W is continued, the infrared light receiving level is detected again (ST17-No). If there is no inspection object W, the inspection is terminated (ST17-Yes).
[0036]
According to the present embodiment, since the infrared sensor 13 is used, when the object passing through the monitoring area is the inspection object W, the detection by the infrared sensor 13 is not performed. On the other hand, in the case of a human body, since the infrared ray emitted from the human body is received, the human body can be immediately detected, and the object W and the human body can be easily distinguished.
[0037]
In any of the above-described embodiments, the X-ray exposure is controlled to a predetermined exposure amount or 0 by controlling ON / OFF of the switching circuit of the X-ray generation unit. (ST3-Yes, ST9-Yes, ST14-Yes), the X-ray exposure dose exposed from the X-ray generator 52 is reduced to an exposure dose that does not affect the human body. It is good.
[0038]
In this case, by receiving a control signal from the control means 10, the power supplied to the X-ray generation tube provided in the X-ray generator 52 is controlled to be less than a preset threshold value, and the X-ray exposure is performed. The exposure dose is reduced to an exposure dose that does not affect the human body (ST4, ST10, ST15). Thereafter, when the light receiving levels of the light receiving element 4b and the infrared sensor 13 change and it is determined that there is no human body in the monitoring area (ST5-Yes, ST11-Yes, ST16-Yes), the X-ray generator 52 The electric power supplied to the X-ray generator tube provided in is controlled to a predetermined threshold value or more, and the X-ray exposure dose is increased to the original exposure dose (ST6, ST12, ST17).
[0039]
In any of the above-described embodiments, as shown in FIG. 1, FIG. 6, and FIG. 12, an alarm device 14 as an alarm means for generating an alarm sound is connected to the control means 10, and FIG. 11 (B) and FIG. 14 (B), when the control means 10 receives the discrimination signal indicating the presence of a human body, FIG. 4 (K), FIG. 11 (H) and FIG. As shown, an alarm signal may be sent from the control means 10 to the alarm device 14, and the alarm device 14 may be activated to generate an alarm sound (ST19). As a result, inadvertent operator who has put a hand to hear the warning sound, so that the pull out the hand from the carry-in port R _in or carry-out port R _out.
[0040]
【The invention's effect】
As described above, the X-ray foreign object detection apparatus according to the present invention controls the amount of X-ray exposure from the X-ray generation unit by detecting the intrusion of the human body into the conveyance path, so that the X-ray exposure can be prevented. The effect of improving the safety of the human body is obtained.
[0041]
Further, by using the light projecting / receiving element, it can be easily attached to an existing apparatus. Further, by providing the position adjusting means, the light emitting / receiving element can be raised to a position higher than the highest inspection object even when the heights of the inspection objects to be sequentially conveyed are different. It is possible to easily discriminate the inspection object.
[0042]
Further, by installing the light projecting / receiving element above the object to be inspected, it is possible to determine that the object passing through the monitoring area is only a human body and is immediately a human body.
[0043]
Further, by providing the warning means, it is possible to immediately notify an operator who has inadvertently put his hand in hand, and the exposure dose can be minimized.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a first embodiment of an X-ray foreign object detection device according to the present invention.
FIG. 2 is a front view showing a first embodiment of an X-ray foreign object detection device according to the present invention.
FIG. 3 is a diagram showing the inside of a conveyance path in the first embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 4 is a timing chart showing a first embodiment of an X-ray foreign object detection device according to the present invention.
FIG. 5 is a flowchart showing a first embodiment of an X-ray foreign object detection device according to the present invention.
FIG. 6 is a schematic block diagram showing another embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 7 is a diagram showing the inside of a conveyance path in another embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 8 is a flowchart showing another embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 9 is a partially enlarged front view showing a second embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 10 is a flowchart showing a second embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 11 is a timing chart showing a second embodiment of the X-ray foreign object detection device according to the present invention.
FIG. 12 is a schematic block diagram showing a third embodiment of an X-ray foreign object detection device according to a reference example of the invention.
FIG. 13 is a flowchart showing a third embodiment of the X-ray foreign object detection device according to the reference example of the invention.
FIG. 14 is a timing chart showing a third embodiment of the X-ray foreign object detection device according to the reference example of the invention.
FIG. 15 is a schematic perspective view showing a conventional X-ray foreign object detection device.
FIG. 16 is a front view of a conventional X-ray foreign object detection device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... X-ray foreign material detection apparatus, 2 ... X-ray generation part, _Rin ... Carry-in entrance, W ... Inspection object, 53 ... X-ray detection part, _Rout ... Carry-out exit, 3 ... Discrimination means, 10 ... Control means, 4 (4a, 4b) ... light emitting / receiving element, t ₀ ... set passage time, 7 ... time measuring means, 11 ... position adjusting means, 13 ... infrared sensor, 14 ... alarm means

Claims (2)

The X-ray generation unit (2) emits X-rays to the inspection object (W) conveyed from the carry- _in port (R _in ), and the X-ray transmission amount is detected by the X-ray detection unit (53). In the X-ray foreign object detection device for carrying out the inspection object from the carry-out port (R _out ),
A pair of facing light projecting / receiving elements (4a, 4b) and the carry-in port or / and the carry-out port are set as a monitoring region, and a preset setting passage corresponding to a time during which the inspection object passes through the monitoring region. Time measuring means (7) for measuring the time (t ₀ ) from the time when the light receiving level of the light receiving element is lowered from a predetermined level, and detecting the presence or absence of an object passing through the monitoring area, Discrimination means (3) for discriminating whether or not the detected object is a human body;
Position adjusting means (11) capable of adjusting the pair of light emitting / receiving elements in the height direction;
And a control means (10) for controlling the X-ray exposure dose exposed from the X-ray generation unit to be less than a predetermined amount when the determination means determines that the object is the human body. ,
The discriminating means discriminates the object passing through the monitoring area as the human body when the light receiving level of the light receiving element after the set passage time has passed is the low level, and the passage after the set passage time has passed. When the light receiving level of the light receiving element is the predetermined level, the object passing through the monitoring area is determined as the inspection object,
The control means controls the position adjusting means to raise the position of the pair of light projecting / receiving elements when the discrimination means discriminates the object as the inspection object. Detection device. The control means, after the X-ray exposure amount is controlled to be less than the predetermined amount, based on the detection signal from the detection means, when it is detected that there is no object determined to be the human body, Controlling the X-ray exposure amount to be greater than or equal to the predetermined amount, and the control means controlling the alarm means to generate an alarm sound when the discrimination means determines that the object is the human body. The X-ray foreign matter detection device according to claim 1 , wherein

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