JP4166738B2 - X-ray foreign object detection device - Google Patents

Description

  The present invention relates to an X-ray foreign matter detection apparatus that performs an inspection (hereinafter referred to as a foreign matter mixing inspection) for detecting foreign matters mixed in an article by conveying an article and irradiating it with X-rays.

  2. Description of the Related Art In a production line for foods and the like, an X-ray foreign matter detection device that uses X-rays to inspect foreign matter contamination for products is used. Here, the X-ray foreign matter detection apparatus irradiates an inspection target article (hereinafter referred to as an inspection object) conveyed using a conveyor or the like and transmits X-rays that pass through the inspection object. The amount is measured, and it is determined whether or not foreign matter is mixed (hereinafter referred to as foreign matter mixing determination) based on the measured transmission amount information.

  Here, examples of the foreign matter to be detected by the X-ray foreign matter detection apparatus include bones such as metal and fish, stones, glass, and plastics. Since the foreign objects to be detected by the X-ray foreign object detection device include those that are not detected by the metal detection device, the X-ray foreign object detection device is effective for the foreign object contamination inspection. When the type of foreign matter to be detected is different, the foreign matter detection sensitivity is generally different. Therefore, in order to make it easier to detect foreign matter, mask X-ray transmission amount, X-ray intensity, threshold for foreign matter determination, and objects intentionally added to the inspection object prior to foreign matter inspection. Various parameters such as the mask area are set.

  The operator carried the object to be inspected on the conveyor a plurality of times, and set each of the above parameters in sequence using the automatic setting function of the X-ray foreign object detection device. Regarding the metal detection device, a technique for setting each parameter by repeating the inversion of the conveyor without carrying the inspection object has been disclosed in consideration of the heavy inspection object and the burden on the operator ( For example, see Patent Document 1.) Similarly, a technique for reversing a conveyor has been disclosed in recent years for an X-ray foreign matter detection apparatus (see, for example, Patent Document 2).

Since the X-ray foreign matter detection apparatus performs foreign matter mixing inspection using X-rays, the dose of X-rays leaked to the outside must be less than or equal to a reference value stipulated by law. Here, according to the law, the dose of X-rays allowed to leak is specified by the exposure amount (unit is Sv), and the total exposure amount is 1.3 mSv or less for 3 months. For this reason, in the X-ray foreign object detection device that has a short machine length in the conveyance direction and may leak X-rays from the conveyance port of the device, the shielding curtain is suspended in the conveyance path inside the device and irradiated from the X-ray generator. X-rays are prevented from leaking outside the X-ray foreign object detection device.
Japanese Utility Model Publication No. 1-78978 JP 2002-148212 A

  However, in such a conventional X-ray foreign object detection device, when performing parameter setting that involves reversing the conveying direction of the conveyor, the object to be inspected on the conveyor does not shield the shielding curtain during the reversing operation that reverses the conveying direction of the conveyor. There is a problem that the X-ray may leak outside the X-ray foreign object detection device because it stops in the open state.

  The present invention has been made to solve such a problem, and an X-ray foreign object detection apparatus capable of preventing X-rays from leaking outside the X-ray foreign object detection apparatus in automatic setting of parameters for defining inspection conditions. Is to provide.

Considering the above points, the invention according to claim 1 is an X-ray for inspecting whether or not foreign matter is mixed in the inspection object by irradiating the inspection object (1) with X-rays. a foreign object detecting device (100), wherein the conveying unit for conveying the inspection object (110), the X-rays the transport unit is irradiated to the inspection object for transporting, the electrons are accelerated by a voltage applied target And an X-ray line sensor (130) for detecting the amount of X-ray transmitted through the inspection object among the X-rays irradiated to the inspection object. And the transport unit covers a space including at least a part of a transport path for transporting the inspection object, accommodates the X-ray generator and the X-ray line sensor therein, and transports the inspection object. A housing having an inlet and an outlet for, and a front in the housing A plurality of shielding curtains, which are provided above the conveyance path and prevent X-rays from leaking from the entrance and the exit, and the inspection object to be inspected in advance by the conveyance unit are defined in advance. In the X-ray foreign object detection apparatus, comprising: a conveyance control means (144) that performs predetermined conveyance control including control for reversing a conveyance direction conveyed by the conveyance unit when performing automatic setting of the parameters to be performed. Article detection means provided in the vicinity of the sensor for detecting the presence / absence of the inspection object, and a process required for the article detection means to pass over the X-ray line sensor after detecting the presence / absence of the inspection object even after time, while conveying the obtaining step product is stopped at a predetermined target position when the transport unit is controlled conveying direction reversed by the transport control unit, the X-ray generator And it has suspended X-ray irradiation by applying a voltage below the voltage which does not generate X-rays, further conveying the start of the conveyance controlling means and the conveying section is reversed transporting direction is controlled by the obtaining step was And an X-ray irradiation control means for starting the X-ray irradiation.

  With this configuration, in the automatic setting of the parameters that define the inspection conditions, the X-ray irradiation control means is based on information from the article detection means, at least while the conveyance is stopped because the conveyance direction is reversed by the conveyance control means. In order to temporarily stop the X-ray irradiation from the X-ray generator, the X-ray foreign object detection device can detect X-rays even if the inspection direction is reversed so that the inspection object stops with the shielding curtain opened. It is possible to realize an X-ray foreign object detection device that can prevent leakage to the outside of the machine and thus can ensure the safety of the operator.

Further , in the automatic setting of parameters for defining the inspection conditions, the X-ray irradiation control means temporarily stops the X-ray irradiation by applying a voltage equal to or lower than the voltage at which the X-ray tube does not generate X-rays to the X-ray tube. Thus, it is possible to realize an X-ray foreign object detection device capable of extremely shortening the time required to stabilize the X-ray intensity as compared with the case where the power supply of the X-ray generator is turned on / off.

Further , the X-ray irradiation control means temporarily stops the X-ray irradiation after the article detection means detects that the inspection object has been conveyed and passed over the X-ray line sensor. An X-ray foreign object detection device that can be used in common with means for performing article detection can be realized.

  According to the present invention, in the automatic setting of parameters for defining the inspection conditions, the X-ray irradiation control means is based on the information from the article detection means, at least while the conveyance is stopped because the conveyance direction is reversed by the conveyance control means. In order to temporarily stop the X-ray irradiation from the X-ray generator, the X-ray foreign object detection device can detect X-rays even if the inspection direction is reversed so that the inspection object stops with the shielding curtain opened. It is possible to provide an X-ray foreign object detection device having an effect of preventing leakage to the outside of the device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an explanatory diagram conceptually showing a block configuration of an X-ray foreign object detection device according to an embodiment of the present invention. An X-ray foreign object detection apparatus 100 according to an embodiment of the present invention includes a transport unit 110 that transports an object to be inspected 1 and an X-ray generator that generates X-rays that irradiate the test object 1 that the transport unit 110 transports. 120, an X-ray line sensor 130 for sensing the amount of X-rays transmitted through the inspection object 1 (hereinafter referred to as transmission X-rays) among the X-rays irradiated to the inspection object 1, and an X-ray line Information regarding the transmission amount of transmitted X-rays output from the sensor 130 is processed to determine whether or not foreign matter is mixed in the inspection object (hereinafter referred to as foreign matter mixing determination), and the conveyance unit 110 and A control processing unit 140 that controls the X-ray generator 120 and a display unit 150 that displays information output from the control processing unit 140 are provided.

  The conveyance unit 110 is configured to include a conveyance belt 111, a roller 112, and a conveyance driving unit 113 such as a motor unit. Two rollers 112 are arranged at the front and rear portions in the transport direction, respectively, and these have a predetermined height in the height direction. The conveyor belt 111 is endless and is wound around a roller 112. The conveyance driving unit 113 is connected to one of the rollers 112 and rotationally drives the roller 112. The transport belt 111 is made of a material that is easy to transmit X-rays and is made of an element other than an element having a large atomic weight.

  The X-ray foreign object detection device 100 further includes a housing 20 that prevents X-rays from leaking to the outside as shown in FIG. FIG. 2 is a perspective view showing an example of the X-ray foreign object detection apparatus 100 according to the embodiment of the present invention. The case 20 includes a radiation source front panel 21 that is opened when handling the transfer unit 110 and the like stored in the case 20, and a transfer unit that is opened when handling the X-ray line sensor 130, the transfer unit 110, and the like. The front panel 22, the rear panel 23 provided on the surface facing the radiation source front panel 21 or the transport unit front panel 22, and parts other than the radiation source front panel 21, the transport unit front panel 22 and the rear panel 23 (for example, The outer side surface portion of the X-ray foreign object detection device 100, etc.).

  The X-ray generator 120 is stored in a space surrounded by the radiation source front panel 21 and the fixing unit 24. Part or all of the transport unit 110 and the X-ray line sensor 130 are stored in a space surrounded by the transport unit front panel 22 and the fixed unit 24. Further, a transport port 221 (consisting of an inlet 221 a and an outlet 221 b) for transporting the inspection object 1 into the X-ray foreign object detection device 100 is provided between the transport unit front panel 22 and the fixed unit 24. ing.

  The transport unit front panel 22 is pivotally supported by a hinge 222 provided at the lower portion of the fixed unit 24, and is configured to be openable to the front side (the front side in the Y-axis direction shown in FIG. 2). The housing 20 is made of a material that hardly transmits X-rays such as metal so that X-rays generated by the X-ray generator 120 do not leak to the outside from portions other than the inlet 221a and the outlet 221b.

  FIG. 3 is a cross-sectional view of the X-ray foreign object detection device 100 on a surface parallel to the surface of the conveyor belt 111 on the surface of the conveyor belt 111. The X-ray foreign object detection apparatus 100 receives the inspection object 1 conveyed from the outside in the X-axis direction via the conveyance port 221 (inlet 221a) and discharges it to the outside from the other conveyance port 221 (outlet 221b). It is like that. However, as will be described later, when the parameters for defining the inspection conditions (hereinafter referred to as inspection condition defining parameters) are automatically set, the inspection object 1 is not moved in and out through the transport port 221. .

  FIG. 4 is a cross-sectional view along the conveyance direction for conceptually explaining the configuration in the vicinity of the space in which the inspection object 1 in the housing 20 is conveyed. As shown in FIGS. 3 and 4, a plurality of shielding curtains 11 and 12 that prevent X-rays from leaking from the entrance 221 a and the exit 221 b are provided on the conveyance path in the housing 20. Here, the shielding curtain 11 is provided suspended from the housing 20 so as to close the inlet 221a and the outlet 221b of the housing 20.

  On the other hand, the shielding curtain 12 is provided between the shielding curtain 11 and the X-ray line sensor 130. Here, between the shielding curtain closest to the X-ray line sensor 130 (or the X-ray generator 120) and the X-ray line sensor 130, is X-rays irradiated and foreign matter mixed in the inspection object 1? A predetermined distance is ensured so that the conveyance speed of the inspection object 1 can be appropriately ensured when the foreign matter mixing inspection is performed.

  Hereinafter, the space on the conveyance path in the housing 20 partitioned by the two shielding curtains 11 is referred to as a conveyance space, and the nearest shielding curtain of the X-ray line sensor 130 (or the X-ray generator 120) in the conveyance space. A space partitioned by 12 is called a detection space. Specifically, the shielding curtains 11 and 12 are provided to be suspended from the housing 20 in the conveyance space excluding the detection space.

  As shown in FIG. 4, the X-ray generator 120 is generated by a cylindrical X-ray tube 121 that generates X-rays by colliding electrons accelerated by applying a voltage with a target, and an X-ray tube 121. The irradiation slit 122 for irradiating the X-rays toward the X-ray line sensor 130, and the shutter 123 that opens and closes the irradiation slit 122 to enable irradiation of the inspection object 1 or temporarily stop the irradiation. Hereinafter, the voltage for accelerating electrons to collide with the target is referred to as acceleration voltage.

  The X-ray tube 121 is cooled, for example, immersed in an insulating oil held inside a metal box. The X-ray tube 121 is also provided so that its longitudinal direction is orthogonal to the conveyance direction of the inspection object 1 (X-axis direction shown in FIG. 2). The X-rays generated by the X-ray tube 121 are directed toward the X-ray line sensor 130 through the irradiation slit 122 along the longitudinal direction of the X-ray tube 121, and the substantially conical X-rays are converted into a substantially triangular screen. It comes to irradiate in the shape.

  As shown in FIG. 4, an article detection unit 114 that detects that the inspection object 1 has passed over the X-ray line sensor 130 is provided in the vicinity of the X-ray line sensor 130. Hereinafter, in order to distinguish the article detection means 114 from the article detection means 115 described later, the article detection means 114 is referred to as a passage detection means 114. When the passage detection unit 114 detects that the inspection object 1 has passed over the X-ray line sensor 130, the passage detection unit 114 determines a passage detection signal indicating that the inspection object 1 has passed over the X-ray line sensor 130. To output.

  The X-ray line sensor 130 has a configuration in which the X-ray sensors are arranged in an array, and the transmitted X-rays that pass through the inspection object 1 conveyed on the X-ray line sensor 130 and reach the X-ray sensor. The amount is detected by each X-ray sensor constituting the array, and an electric signal corresponding to the detected transmission amount of the X-ray is output. Although not shown, the X-ray line sensor 130 is arranged in an array in, for example, a direction (Y-axis direction shown in FIG. 2) perpendicular to the conveyance direction of the inspection object 1 conveyed on the conveyance belt 111. An array line sensor including a plurality of photodiodes and a scintillator provided on the photodiode is used. The X-ray line sensor 130 is known and will not be described further.

  In the X-ray line sensor 130 having such a configuration, when the inspection object 1 is irradiated with X-rays from the X-ray generator 120, the X-ray transmitted through the inspection object 1 is received by the scintillator and converted into light. Convert. Further, the light converted by the scintillator is received by a photodiode disposed below the light. Each photodiode converts the received light into an electrical signal and outputs it to the control processing unit 140 as an array signal. Here, the array signal may be output to the control processing unit 140 after being converted into a digital signal.

  The passage detection unit 114 includes, for example, a light source that emits a light beam and a light receiver that receives the light beam emitted from the light source, and the light receiver cannot receive the light beam while the light source emits the light beam. It may be configured by a so-called projector / receiver that detects this and detects the entry of the article. The position where the light projector / receiver monitors the entry of the inspection object 1 is referred to as a monitoring position. When the light projector / receiver is used as the passage detection means 114, the signal generated by the light receiver is output to the control processing unit 140 as a passage detection signal. To do.

  Further, the light projecting / receiving device as the passage detection means 114 differentiates a signal generated when the light is received, and indicates a pulse signal (hereinafter referred to as a monitoring position) indicating that the inspection object 1 has entered the monitoring position of the passage detection means 114. And a pulse signal indicating that the vehicle has passed the monitoring position of the passage detection means 114 (hereinafter referred to as a monitoring position passage pulse signal) is output to the control processing unit 140 as the passage detection signal. Good.

  When a projector / receiver is used as the passage detection means 114 and the monitoring position is more than a predetermined value away from the position where the X-ray line sensor 130 is disposed, the inspection object 1 has passed over the X-ray line sensor 130 It is assumed that the control processing unit 140 performs predetermined signal processing. The detection that the inspection object 1 has passed over the X-ray line sensor 130 can be performed based on information on the conveyance speed and the distance between the monitoring position and the X-ray line sensor 130.

  Hereinafter, the “output signal from the light receiver”, the “monitoring position approach pulse signal”, and the “monitoring position passing pulse signal” are included in the “passing detection signal”, and a projector / receiver is used as the passage detecting means 114. The “output signal from the light receiver” will be described as the “passage detection signal”. Although FIG. 4 shows the case where the passage detection unit 114 is provided to monitor the left side of the X-ray line sensor 130, the X-ray line may be provided to monitor the X-ray line sensor 130. Whether it is provided so as to monitor the right side of the sensor 130 or so as to monitor both sides of the X-ray line sensor 130, other positions where the passage on the X-ray line sensor 130 can be detected are monitored. May be provided.

  Further, as shown in FIG. 4, an article for detecting that the inspection object 1 has reached the vicinity of the outlet 221 b in the casing 20 in the vicinity of the shielding curtain 11 provided at the outlet 221 b in the casing 20. Detection means 115 is provided. Hereinafter, in order to distinguish the article detection means 115 from the article detection means 114, the article detection means 115 is referred to as arrival detection means 115. When the arrival detection means 115 detects that the inspection object 1 has reached the vicinity of the exit 221b, the arrival detection means 115 outputs an arrival detection signal indicating that the inspection object 1 has reached the vicinity of the exit 221b to the X-ray irradiation control means 143. It is like that.

  The arrival detection means 115 may be configured by, for example, the above-described projector / receiver. 4 shows the case where the arrival detection means 115 is provided so as to monitor the vicinity of the outlet 221b in the housing 20, but it may be provided so as to monitor the vicinity of the inlet 221a in the housing 20. You may provide so that the vicinity of both the entrance 221a in the housing | casing 20 and the exit 221b may be monitored. Furthermore, although the case where both the passage detection unit 114 and the arrival detection unit 115 are provided has been described above, either the passage detection unit 114 or the arrival detection unit 115 may not be provided.

  The control processing unit 140 includes an array signal that is information on the amount of transmitted X-rays from the X-ray line sensor 130, a passage detection signal from the passage detection unit 114, a arrival detection signal from the arrival detection unit 115, and an operation unit (not shown). Other signals such as an operation signal corresponding to the operation input from are input. The control processing unit 140 includes an image processing unit 141 that performs predetermined information processing such as image processing for generating a transmission image in the inspection object 1 based on the array signal input from the X-ray line sensor 130, and image processing. Based on the information of the transmission image output from the means 141, foreign matter mixing determination is performed, and predetermined information necessary for control performed by an X-ray irradiation control means 143 and a conveyance control means 144 described later is generated and output. A determination unit 142, an X-ray irradiation control unit 143 for controlling the X-ray generator 120 to generate X-rays or temporarily stop the X-rays according to the signal output from the determination unit 142, and the determination unit In accordance with a signal output from 142, a transport control unit 144 that controls the transport unit 110 is provided. Here, the control performed by the transport control unit 144 includes control for reversing the transport direction when the inspection condition defining parameter is automatically set.

  FIG. 5 is a diagram showing a block configuration of the control processing unit 140 constituting the X-ray foreign object detection device 100 according to the embodiment of the present invention. The control processing unit 140 includes an input interface 541 to which a predetermined signal is input, a CPU (Central Processing Unit) 542 that performs predetermined information processing and control for realizing the functions of the X-ray foreign object detection device 100, and a CPU 542. OS (Operating System) for starting up, ROM (Read Only Memory) 543 for storing other program and control condition defining parameters for control, etc., and execution codes and data of the OS and applications used by the CPU 542 for operation RAM (Random Access Memory) 544 and EEPROM (Electrically Erasable Programmable) that stores application software and predetermined data in a nonvolatile manner ROM) 545 and an output interface 546 for outputting a predetermined signal.

  In the above description, the configuration using the EEPROM 545 as the storage means for storing application software and predetermined data in a non-volatile manner has been described. However, the storage means is not limited to the EEPROM 545 and may be a hard disk or other non-volatile storage element. Good. Hereinafter, the term “EEPROM 545” means storage means for storing in a nonvolatile manner.

  Here, the input interface 541 includes an array signal from the X-ray line sensor 130, a passage detection signal from the passage detection unit 114, a arrival detection signal from the arrival detection unit 115, an operation signal from an operation unit (not shown), and the like. A signal is input. Other signals may include, for example, a mode designation signal for designating the operation mode of the X-ray foreign object detection device 100, a signal received by communication when performing predetermined control, and the like. The signal input to the input interface 541 is not limited to a digital signal, and includes an analog signal as necessary. In this case, the input interface 541 may include a configuration unit that converts an analog signal into a digital signal.

  Under the control of the CPU 542, the output interface 546 outputs a determination signal indicating the determination result of the foreign object mixing determination to an external device (not shown) such as a sorter. The output interface 546 outputs a radiation source control signal for controlling the X-ray generator 120, a transport control signal for controlling the transport unit 110, and other signals. Examples of the other signals include predetermined signals such as a signal for controlling the display unit 150 and the like and a signal transmitted by communication when performing the control. Further, the signal output from the output interface 546 is not limited to a digital signal, and includes an analog signal as necessary. In this case, the output interface 546 is assumed to have a configuration unit that converts a digital signal into an analog signal.

  The CPU 542 of the control processing unit 140 detects foreign matter based on an array signal input from the X-ray line sensor 130 via the input interface 541 when the X-ray generator 120 irradiates the inspection object 1 with X-rays. Mixing judgment is performed. The foreign substance contamination determination performed by the CPU 542 is based on the array signal input via the input interface 541 when the portion where the X-ray transmission amount is less than or equal to a preset threshold is detected. It is determined that foreign matter is mixed. In addition, said threshold value shall differ according to the kind of to-be-inspected object 1 and the foreign material mixed in to-be-inspected object 1. FIG. The determination of mixing of foreign matters is well known, and other detailed description is omitted.

  In addition, when the inspection condition defining parameter is automatically set, the CPU 542 generates a transmission image only in the same conveyance direction as the conveyance performed in the foreign matter mixing inspection, but the transmission is performed in each conveyance direction of the conveyance to be reversed. An image may be generated. When generating a transmission image only in the same direction as the conveyance direction of the conveyance performed in the foreign substance contamination inspection, the temporary stop of X-ray irradiation, which will be described in detail later, is performed after the inspection object 1 is detected. The conveyance may be reversed to return to the original stop position, and stopped until the conveyance is started again from the original stop position.

  The CPU 542 also controls the generation of X-rays based on the detection signal of one of the passage detection signal and the arrival detection unit 115 input from the passage detection unit 114 in the automatic setting of the inspection condition defining parameter. A source control signal to be transmitted is output to the X-ray generator 120, and a transport control signal for controlling transport is output to the transport unit 110.

  When the notification detection signal is input from the passage detection unit 114 and the passage detection unit 114 is provided in the relative positional relationship shown in FIG. 4 or 6 with respect to the X-ray line sensor 130, the CPU 542 After 1 passes through the monitoring position of the passage detecting means 114, the time required for completely passing through the X-ray line sensor 130 (the inspection object 1 moves to the position of the inspection object 1 ′ shown in FIG. 6) ( Hereinafter, after the passage of the passage time, the source control signal for causing the X-ray generator 120 to temporarily stop generation or irradiation of X-rays is output.

  In the case where the passage detection means 114 is provided on the exit 221b side of the X-ray line sensor 130 and the inspection object 1 is transported from the stop position on the exit 221b side to the entrance 221a side, the CPU 542 Works as well. When the passage detection means 114 is provided on the outlet 221b side of the X-ray line sensor 130 and the inspection object 1 is transported from the stop position on the inlet 221a side to the outlet 221b side, the inspection object 1 The time required for the inspected object 1 to completely pass through the X-ray line sensor 130 after detecting that it has entered the monitoring position of the light projecting / receiving device as the passage detecting means 114 (hereinafter referred to as elapsed time after entering). ) Elapses, the X-ray generator 120 outputs a radiation source control signal for temporarily stopping the generation or irradiation of the X-rays.

  Even when the passage detection means 114 is provided on the outlet 221b side of the X-ray line sensor 130 and the inspection object 1 is transported from the stop position on the inlet 221a side to the outlet 221b side, the inspection object 1 Source control that causes the X-ray generator 120 to temporarily stop generation or irradiation of X-rays after a lapse of time after entering after detecting that the projector has entered the monitoring position of the light projecting / receiving device as the passage detecting means 114 Output a signal. It is assumed that the information about the elapsed time after passage and the elapsed time after entry is written in the EEPROM 545 in advance. However, it may be read from the EEPROM 545 and stored in the RAM 544 in advance. The ROM 543 stores information on the distance necessary to calculate the elapsed time after passage and the elapsed time after entry, information on the conveyance speed, and the like, and the elapsed time after passage based on these information stored in the ROM 543. Alternatively, the elapsed time after entering may be calculated.

  Here, when the generation of X-rays is temporarily stopped by the X-ray generator 120, the acceleration voltage is lowered to a voltage not generating X-rays or the acceleration voltage is made zero. To do. In addition, when the generation of X-rays is not temporarily stopped and the X-ray irradiation is temporarily stopped, the shutter 123 is closed. The source control signal output from the control processing unit 140 to the X-ray generator 120 may be a predetermined single pulse signal, a plurality of pulse signals, or a digital signal.

  The control processing unit 140 holds and operates the following information in order to perform control to reverse the transport direction of the transport unit 110. First, information on a position (hereinafter referred to as a target position) predetermined as a position desired to be stopped in each conveyance direction and information on a braking distance required to stop conveyance for each inspection object 1 are stored in advance in EEPROM 545. It is assumed that the information is stored in the memory. Note that the conveyance profile may be further stored.

  Hereinafter, the operation of each component in the automatic setting of the inspection condition defining parameter will be described with reference to FIG. Here, as the inspection condition defining parameters, for example, in order to mask the amount of X-ray transmission, the intensity of X-rays, the threshold for mixing determination, the type of transmission image creation processing, and what is intentionally added to the inspection object The mask area is increased. In setting the inspection condition defining parameters, the operator simply opens the transport unit front panel 22 and places the inspection object 1 in the detection space. After that, any of the panels 21, 22, 23 is also not open.

  In the following description, it is assumed that the control is performed from the state where the inspection object is stopped at the position of the inspection object 1 shown in FIG. Also, the control of the X-ray generator 120 will be described on the assumption that X-ray generation or temporary stop is performed and the shutter 123 is not opened and closed. Further, the generation and suspension control of X-rays are performed by switching the acceleration voltage.

First, the CPU 542 of the control processing unit 140 outputs a conveyance control signal instructing the start of conveyance to the conveyance driving unit 113, and transmits an X-ray source control signal for controlling the X-ray generator 120 to generate X-rays. Output to the generator 120. When the source control signal from the control processing unit 140 is input, the X-ray generator 120 changes the acceleration voltage from the voltage V _OFF that does not generate X-rays to X-rays as shown in FIG. Is switched to the voltage V _{ON at} which is generated.

When the X-ray generator 120 switches the acceleration voltage from V _OFF to V _ON , the X-ray intensity generated by the X-ray generator 120 is the passage detection means 114 for the object to be inspected 114 as shown in FIG. Stabilize before reaching the monitoring position. Here, the time required for the X-ray intensity to stabilize is usually about 1 second.

  Next, when the inspection object 1 enters the monitoring position of the passage detection means 114, the light emitted from the projector is blocked by the inspection object 1, and a DC signal having a level of zero, that is, a noise level, passes from the light receiver. The detection signal is output to the control processing unit 140. Hereinafter, the level of the DC signal output from the light receiver to the control processing unit 140 when the light emitted from the projector is blocked by the inspection object 1 is simply referred to as level zero.

  Further, when the inspection object 1 is conveyed in the direction toward the outlet 221b, the inspection object 1 passes through the monitoring position of the passage detection means 114, and the output from the light receiver becomes a predetermined value of level zero or more again. The CPU 542 of the control processing unit 140 detects that the level of the signal output from the passage detection unit 114 has risen from the level zero to a predetermined value, and the inspection object 1 has passed the monitoring position of the passage detection unit 114. Detect that.

When the CPU 542 of the control processing unit 140 detects that the inspection object 1 has passed the monitoring position of the passage detection unit 114, the CPU 542 transmits the elapsed time after passage to the X-ray generator 120 via the output interface 546. A source control signal for instructing to temporarily stop X-rays is output. When the X-ray source control signal instructing the temporary stop of the X-ray is input, the X-ray generator 120 switches the acceleration voltage from V _ON to V _OFF .

  When the CPU 542 of the control processing unit 140 outputs a radiation source control signal that instructs the X-ray generator 120 to temporarily stop X-rays, the CPU 542 controls the conveyance so that the inspection object 1 is stopped at the target position. When the inspection object 1 stops at the target position, a conveyance control signal for controlling the conveyance direction to be reversed and conveying the inspection object 1 from the outlet 221b side to the inlet 221a side is output to the conveyance driving means 113.

  When the inspection object 1 is conveyed in the conveyance direction after reversal, X-ray irradiation is started, and the inspection object 1 passes over the X-ray line sensor 130 and enters the monitoring position, the light emitted from the projector is emitted. A zero-level DC signal is output from the light receiver to the control processing unit 140 as a passage detection signal.

  When detecting that the level of the signal output from the light receiver has changed to zero, the CPU 542 of the control processing unit 140 measures the elapsed time from when the signal level has changed to level zero, Information is read from the EEPROM 545 (may be read in advance and stored in the RAM 544 and read from the RAM 544).

When the CPU 542 determines that the elapsed time during measurement has reached the elapsed time after entering, the CPU 542 outputs a source control signal instructing the temporary stop of the X-rays to the X-ray generator 120. When the X-ray source control signal instructing the temporary stop of the X-ray is input, the X-ray generator 120 switches the acceleration voltage from V _ON to V _OFF . When the CPU 542 outputs to the X-ray generator 120 a radiation source control signal instructing a temporary stop of X-rays, the CPU 542 stops the inspection object 1 at the target position (stop position) on the inlet 221a side.

  In the above transport control, the control processing unit 140 outputs a transport control signal to the transport driving unit 113 and determines that a predetermined time has elapsed (that is, the inspection object 1 has stopped at the target position on the inlet 221a side). When the determination is made), the above-described operation is repeated for the number of times of inversion input via an operation unit (not shown) to automatically set the inspection condition defining parameter.

  In the above description, the case where the X-ray generator 120 operates to generate or pause X-rays according to the source control signal has been described. However, instead of generating or temporarily stopping X-rays, the shutter 123 is opened and closed. X-ray irradiation or temporary stop may be performed. The operation when the X-ray generator 120 irradiates or pauses X-rays in accordance with the source control signal is used instead of the X-ray generator 120 generating or temporarily stopping X-rays in accordance with the source control signal. The operation is the same as the above operation except that X-ray irradiation or temporary suspension is performed, and the description thereof is omitted.

  In addition, although it has been described that the inspection unit 1 is set in the detection space by opening the transport unit front panel 22, the inspection condition defining parameter is set. The inspection condition defining parameter may be set after the transport control means 144 moves the control position to the control start position.

  As described above, the X-ray foreign matter detection apparatus according to the embodiment of the present invention is configured so that the X-ray irradiation control means is at least transported based on information from the article detection means in the automatic setting of parameters that define the inspection conditions. In order to temporarily stop the X-ray irradiation from the X-ray generator while the transport is stopped because the transport direction is reversed by the control means, the transport direction is such that the inspection object stops with the shielding curtain opened. Even if the reversal is performed, it is possible to prevent X-rays from leaking outside the X-ray foreign object detection device, thereby ensuring the safety of the operator.

  Further, in the automatic setting of parameters for defining the inspection conditions, the X-ray irradiation control means temporarily stops the X-ray irradiation by applying a voltage equal to or lower than the voltage at which the X-ray tube does not generate X-rays to the X-ray tube. The time required to stabilize the X-ray intensity can be greatly reduced as compared with the case where the supply power of the X-ray generator is turned on / off.

  Further, in the automatic setting of parameters for defining the inspection conditions, the X-ray irradiation control means temporarily stops the X-ray irradiation by closing the exit of the irradiation slit with the shutter, so that it does not take time to stabilize the X-ray intensity. A wire foreign object detection device can be realized.

  Further, the X-ray irradiation control means temporarily stops the X-ray irradiation after the article detection means detects that the inspection object has been conveyed and passed over the X-ray line sensor. It can be used in common with the means for performing article detection.

  Further, the X-ray irradiation control means temporarily stops the X-ray irradiation when the article detection means detects that the inspection object has been conveyed and has reached the vicinity of the entrance and the exit. X-ray irradiation can be stopped before the shielding curtain provided in the vicinity is opened, and leakage of X-rays while the inspection object is being transported can be reduced.

  The X-ray foreign object detection device according to the present invention is useful for an X-ray foreign object detection device and the like that have an effect of preventing leakage of X-rays from the X-ray foreign object detection device when performing parameter setting processing. It can also be applied to.

Explanatory drawing which shows notionally the block structure of the X-ray foreign material detection apparatus which concerns on embodiment of this invention The perspective view which shows an example of the X-ray foreign material detection apparatus which concerns on embodiment of this invention Sectional view in a plane parallel to the conveyor belt surface on the conveyor belt surface of the X-ray foreign matter detector Sectional drawing along the conveyance direction which illustrates notionally the structure of the space vicinity where the to-be-inspected object in a housing | casing is conveyed. The figure which shows the block configuration of the control processing part which comprises the X-ray foreign material detection apparatus which concerns on embodiment of this invention. Explanatory drawing for demonstrating operation | movement of the X-ray foreign material detection apparatus which concerns on embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection object 11, 12 Shielding curtain 20 Case 21 Radiation source front panel 22 Conveyance part front panel 23 Rear panel 24 Fixed part 100 X-ray foreign material detection apparatus 110 Conveyance part 111 Conveyance belt 112 Roller 113 Conveyance drive means 114 Article detection means (Passage detection means)
115 Article detection means (arrival detection means)
DESCRIPTION OF SYMBOLS 120 X-ray generator 121 X-ray tube 122 Irradiation slit 123 Shutter 130 X-ray line sensor 140 Control processing part 141 Image processing means 142 Judgment means 143 X-ray irradiation control means 144 Conveyance control means 150 Display part 221, 221a, 221b Conveyance port 222 Hinge 541 Input interface 542 CPU
543 ROM
544 RAM
545 EEPROM
546 Output interface

Claims (1)

An X-ray foreign matter detection apparatus (100) for inspecting whether or not foreign matter is mixed in the inspection object by irradiating the inspection object (1) with X-rays,
A transport section (110) for transporting the inspection object;
The X-rays the transport unit is irradiated to the inspection object for transporting, X-ray generator for generating by colliding electrons are accelerated by a voltage applied to the target (120),
An X-ray line sensor (130) that senses the amount of X-rays transmitted through the inspection object among the X-rays irradiated to the inspection object;
The transport unit covers a space including at least a part of a transport path for transporting the inspection object, accommodates the X-ray generator and the X-ray line sensor therein, and transports the inspection object. A housing having an inlet and an outlet;
A plurality of shielding curtains provided above the conveyance path in the housing and preventing X-rays from leaking from the inlet and the outlet;
When carrying out automatic setting of parameters for prescribing the inspection object in advance by the conveyance unit and prescribing the inspection conditions, predetermined conveyance control including control for reversing the conveyance direction conveyed by the conveyance unit is performed. In the X-ray foreign object detection device comprising the conveyance control means (144) for performing,
Article detection means provided in the vicinity of the X-ray line sensor for detecting the presence or absence of the inspection object;
After the elapsed time from when the article detection means detects the presence or absence of the inspection object until it passes over the X-ray line sensor, the conveyance control unit is controlled by the conveyance control means and the conveyance direction is reversed. while conveying the obtaining step product is stopped at a predetermined target position when the temporary stops the X-ray irradiation by applying a voltage below the voltage which does not generate X-rays to the X-ray generator, And X-ray irradiation control means for starting X-ray irradiation after the transfer control unit is controlled by the transfer control means and the transfer direction is reversed and transfer of the inspection object is started. Wire foreign matter detection device.

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