Patent Publication Number: US-2017350831-A1

Title: X-ray inspection device

Description:
PRIORITY 
     This is a National Stage Application under 35 U.S.C. §365 of International Application PCT/JP2015/078132, with an international filing date of Oct. 5, 2015, which claims priority to Japanese Patent Application No. 2014-232130 filed on Nov. 14, 2014. The entire disclosures of International Application PCT/JP2015/078132 and Japanese Patent Application No. 2014-232130 are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Certain implementations of the present invention relate to an X-ray inspecting apparatus. 
     BACKGROUND 
     In a production line for foodstuffs or other products, inspections are in some cases made by an X-ray inspecting apparatus so that products contaminated with foreign materials are not shipped out. In this X-ray inspecting apparatus, goods being conveyed are irradiated with X-rays, and the state of X-ray transmissivity is detected by a detection part to inspect whether or not the goods have been contaminated with foreign materials. 
     SUMMARY 
     X-ray inspection apparatuses that employ an X-ray detection part having numerous elements disposed in a straight line have been widely used in recent years. 
     However, when there is an increase in the number of elements provided to the X-ray detection part and the elements are disposed on the X-ray-incident side of the scintillators, the costs of manufacturing including assembly tend to rise. 
     An object of certain implementations of the present invention is to provide an X-ray inspecting apparatus with which X-rays of a broad energy band can be detected while manufacturing costs are suppressed. 
     An X-ray inspecting apparatus according to a first aspect includes an X-ray source, a detection part, an image production part, and an inspection part. The X-ray source radiates X-rays onto goods to be inspected. The detection part detects X-rays of a predetermined energy band and visible light rays of a predetermined wavelength band, and generates a signal. The image production part produces an image on the basis of the signal generated by the detection part. The inspection part inspects the goods on the basis of the image produced by the image production part. Additionally, the detection part has a plurality of detection units. Each of the plurality of detection units has a scintillator extending in a predetermined direction, a detection main body, and a base. The scintillators emit visible light rays of the predetermined wavelength band by absorbing X-rays of an energy band higher than the predetermined energy band. The detection main bodies include a plurality of elements. The plurality of elements are disposed on the sides of the scintillators that face the X-ray source, and are aligned in the predetermined direction in which the scintillators extend. The plurality of elements are sensitive to X-rays of the predetermined energy band and visible light rays of the predetermined wavelength band, and the elements generate the signal. The bases support the scintillators and the detection main bodies. The plurality of detection units are aligned along the predetermined direction within the detection part so that the scintillators and the detection main bodies of any of the detection units are aligned without gaps with the scintillators and the detection main bodies of adjacent detection units. 
     In this aspect, because the plurality of elements are disposed on the side of the scintillator that faces the X-ray source, X-rays are directly incident on the elements, and X-rays of a predetermined energy band are detected by the elements. X-rays of an energy band higher than the predetermined energy band are also detected by the elements because these X-rays are converted to visible light rays of a predetermined wavelength band by the scintillator. Thus, the detection units are able to detect X-rays of a broad energy band. 
     If a configuration were used in which all of the elements are aligned on one unit, the unit would be larger in size and manufacturing costs would rise for reasons such as assembly being more difficult, but in this aspect, the configuration employed has a plurality of detection units aligned in a predetermined direction. Manufacturing costs are thereby suppressed. 
     Furthermore, when the configuration employed has an alignment of detection units in which a plurality of elements are disposed on the sides of the scintillators that face the X-ray source, there is a risk that the elements and the scintillators would not be continuous in the borders of adjacent detection units. However, in the X-ray inspecting apparatus according to the first aspect, the plurality of detection units are aligned in a predetermined direction so that the scintillators and the detection main bodies of the detection units are aligned without gaps with the scintillators and the detection main bodies of the adjacent detection units. Therefore, the continuity of the elements and the scintillators is ensured, and the problem of X-ray sensitivity being lowered in any section along the predetermined direction is suppressed. 
     An X-ray inspecting apparatus according to a second aspect is the X-ray inspecting apparatus according to the first aspect, wherein the bases of the detection units are made of a ceramic material. 
     In this aspect, because ceramic bases of high hardness are employed, if two bases of adjacent detection units are brought into contact and the relative positions thereof are fixed, there are not likely to be situations in which the bases then deform to compromise the continuity of the elements and the scintillators. 
     An X-ray inspecting apparatus according to a third aspect is the X-ray inspecting apparatus according to the first or second aspect, wherein the scintillators, the detection main bodies, and the bases are of equal length in the predetermined direction among the plurality of detection units. 
     In this aspect, when the bases of adjacent detection units are brought in contact and the relative positions thereof are determined, the scintillators and the detection main bodies naturally come to be aligned without gaps in the borders of the detection units. Therefore, the assembly steps, including the step of aligning the plurality of detection units, are simplified, and consequently, manufacturing costs fall. 
     An X-ray inspecting apparatus according to a fourth aspect is the X-ray inspecting apparatus according to any of the first through third aspects, wherein each of the detection main bodies has a fixed part fixed to the base, and an overhanging part protruding from an end of the base. The plurality of elements are included in the overhanging part. 
     In this aspect, because the elements are disposed on the overhanging parts of the detection main bodies protruding from the bases, even in a structure that has the X-ray source, the elements, and the scintillators aligned, it is possible to achieve a state in which there are no bases between the X-ray source and the elements. 
     Specifically, if the elements were to be included on the fixed parts fixed to the bases, the alignment would be the bases, the elements, and the scintillators, and X-rays would first pass through the bases should X-rays be caused to be incident not from the scintillator-side but from the element-side. The bases generally have high X-ray absorptivity, and the output of the X-ray source would need to be increased in order to maintain detection sensitivity. 
     In contrast, due to the elements being disposed on the overhanging parts in this aspect, it is possible to achieve a detection part that can detect X-rays over a broad energy band with low output, in which X-rays are directly incident on the elements from the X-ray source and X-rays that have passed through the elements are incident on the scintillators. 
     An X-ray inspecting apparatus according to a fifth aspect is the X-ray inspecting apparatus according to the fourth aspect, wherein the X-ray source is positioned above the plurality of elements. The detection part further has a cover member that covers the plurality of elements from above. The cover member has a lower rate of absorption of the X-rays than the bases. 
     In this aspect, because the elements are disposed on the overhanging parts, X-rays enter the elements from the above X-ray source, but there is a risk that dust will collect on and adhere to the tops of the elements. In view of this, the elements are covered from above by the cover panel, and loss of sensitivity of the elements is suppressed. Because the cover panel employed has a lower rate of X-ray absorption than the bases, detection sensitivity can be maintained without increasing the output of the X-ray source. 
     An X-ray inspecting apparatus according to a sixth aspect is the X-ray inspecting apparatus according to the fifth aspect, wherein the detection part further has a support member configured to support a plurality of the detection units. The support member has a first side face contact part which comes into contact with first side faces of the bases of the plurality of detection units. The cover member has a second side face contact part. The second side face contact part comes into contact with second side faces that oppose the first side faces of the bases of the plurality of detection units. The bases of the plurality of detection units are positioned by the first side face contact part of the support member and by the second side face contact part of the cover member. 
     In this aspect, the support member supporting the plurality of detection units and the cover member covering the plurality of elements from above both have a contact part that comes into contact with side faces of the bases of the plurality of detection units. The bases of the plurality of detection units are then positioned by the first side face contact part of the support member and the second side face contact part of the cover member, whereby the scintillators and the detection main bodies supported on the bases are also positioned. The scintillators and detection main bodies of two adjacent detection units are thereby aligned without gaps, and the continuity of the elements and the scintillators is ensured. 
     An X-ray inspecting apparatus according to a seventh aspect is the X-ray inspecting apparatus according to any of the first through third aspects, wherein the detection part further has a support member configured to support the plurality of detection units, and a slitted member. The slitted member, having a slit formed therein through which the X-rays pass, is disposed between the X-ray source and the plurality of detection units. The plurality of detection units are sandwiched between the support member and the slitted member. 
     In this aspect, the state of X-ray detection in the detection part stabilizes because X-rays that have passed through the slit in the slitted member enter the elements and the scintillators. The plurality of detection units are held by being sandwiched between the slitted member and the support member supporting the plurality of detection units. With the scintillators and the detection main bodies of the plurality of detection units aligned without gaps, the plurality of detection units can be maintained as being reliably supported on the support member. 
     With the X-ray inspecting apparatus of certain implementations, X-rays of a broad energy band can be detected because the plurality of elements are disposed on the sides of the scintillators that face the X-ray source. Additionally, manufacturing costs are suppressed because of a configuration is employed in which the plurality of detection units are aligned in the predetermined direction. Furthermore, because the plurality of detection units are aligned in the predetermined direction so that the scintillators and detection main bodies of two adjacent detection units are aligned without gaps, the continuity of the elements and scintillators is ensured, and X-rays of a broad energy band can be detected in all areas along the predetermined direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external perspective view of an X-ray inspecting apparatus according to an embodiment of the present invention; 
         FIG. 2  is a simple configuration diagram of the inside of a shield box of the X-ray inspecting apparatus; 
         FIG. 3  is a control block diagram of the X-ray inspecting apparatus; 
         FIG. 4  is a schematic diagram showing the principle of inspection using X-rays; 
         FIG. 5  is a cross-sectional view of a line sensor assembly sectioned along a plane orthogonal to the longitudinal direction; 
         FIG. 6  is an enlarged view of part of  FIG. 5 ; 
         FIG. 7A  is a plan view showing the assembly procedure for the line sensor assembly; 
         FIG. 7B  is a cross-sectional view along line VIIB-VIIB of  FIG. 7A ; 
         FIG. 8A  is a plan view showing the assembly procedure for the line sensor assembly; 
         FIG. 8B  is a cross-sectional view along line VIIIB-VIIIB of  FIG. 8A ; 
         FIG. 9  is a plan view showing the assembly procedure for the line sensor assembly; 
         FIG. 10A  is a plan view showing the assembly procedure for the line sensor assembly; and 
         FIG. 10B  is a cross-sectional view along line XB-XB of  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION 
     (1) Overall configuration 
     An external view of an X-ray inspecting apparatus according to an embodiment of the present invention is shown in  FIG. 1 . This X-ray inspecting apparatus  10 , which inspects whether or not there are foreign materials in goods on a production line for foodstuffs and other goods, radiates X-rays onto continuously conveyed goods and determines whether or not foreign materials are included in the goods on the basis of the quantity of X-rays transmitted through the goods. It is supposed that foreign materials as small as approximately 0.5 mm would be detected in the X-ray inspecting apparatus  10 . 
     The X-ray inspecting apparatus  10  determines whether or not goods which are the articles to be inspected in the X-ray inspecting apparatus  10 , contain foreign materials, and when the goods are determined by the X-ray inspecting apparatus  10  to contain foreign materials, the goods are sorted as inferior products by a sorting apparatus  70  (see  FIG. 4 ) disposed on the downstream side of the X-ray inspecting apparatus  10 . 
     The X-ray inspecting apparatus  10  is configured from a shield box  11 , a conveyor  12 , an X-ray radiation device  13 , a line sensor assembly  14 , an LCD monitor  30  with a touch panel function, a control computer  20 , etc., as shown in  FIGS. 1 and 2 . The X direction, Y direction, and Z direction shown in the drawings represent, respectively: the left-right direction, which is the direction in which the goods G are conveyed; the forward-backward direction, which is the longitudinal direction of the line sensor assembly  14 ; and the up-down direction, which is the height direction. 
     (2) Detailed configuration 
     (2-1) Shield Box 
     The shield box  11  has openings  11   a  in both sides. The openings  11   a  are open portions for conveying the goods G in and out. Part of the conveyor  12 , the X-ray radiation device  13 , the line sensor assembly  14 , the control computer  20 , etc. are housed within the shield box  11 . 
     The openings  11   a,  which serve as openings to convey the goods G in and out, are closed by shielding curtains  16  for suppressing leakage of X-rays to the exterior of the shield box  11 . The shielding curtains  16  are molded from rubber containing lead, and are pushed apart by the goods G when the goods G are conveyed in or out. 
     In addition to the LCD monitor  30 , a key insertion hole and/or a power source switch is also disposed in the upper part of the front face of the shield box  11 . 
     (2-2) Conveyor 
     The conveyor  12  conveys goods G inside the shield box  11 , and the conveyor is driven by a conveyor motor  12   a  shown in  FIG. 4 . The conveying speed of the conveyor  12  is precisely controlled through inverter control of the conveyor motor  12   a  by the control computer  20 . 
     (2-3) X-Ray Radiation Device 
     The X-ray radiation device  13 , which is an X-ray source disposed above the central portion of the conveyor  12 , radiates X-rays (refer to the symbol XR in  FIG. 2  etc.) toward the line sensor assembly  14  underneath, as shown in  FIG. 2 . Specifically, the X-ray radiation device  13  radiates X-rays onto the goods G to be inspected, which are placed on and conveyed by the conveyor  12  underneath. 
     (2-4) LCD Monitor 
     The LCD monitor  30 , which is a liquid crystal display that uses a full-dot display, displays X-ray images and/or foreign material determination results. The LCD monitor  30  also has a touch panel function, and also displays a screen prompting, inter alia, input of parameters pertaining to initial settings and/or foreign material inspection. 
     (2-5) Control Computer 
     The control computer  20  is equipped with a CPU  21 , and is also equipped with a ROM  22 , a RAM  23 , and a hard disk drive (HDD)  25  as main storage parts controlled by the CPU  21 , as shown in  FIG. 4 . The CPU  21 , the ROM  22 , the RAM  23 , the HDD  25 , and other components are connected to each other via an address bus, a data bus, and other bus lines. By executing control programs, the CPU  21  fulfills the role of functional parts; namely, an X-ray image production part  21   a,  a foreign material presence/absence inspection part  21   b,  and a display control part  21   c.    
     The control computer  20  is also connected with the conveyor motor  12   a,  the X-ray radiation device  13 , the line sensor assembly  14 , the LCD monitor  30 , the sorting apparatus  70 , etc. 
     (2-6) Line Sensor Assembly 
     The line sensor assembly  14 , which is disposed underneath the conveyor  12  as shown in  FIG. 2 , is an assembly that detects X-rays radiated downward from the X-ray radiation device  13  and transmitted through the goods G and conveyor  12 , creates a detection signal, and provides the detection signal to the control computer  20 . 
     The line sensor assembly  14  is configured mainly from first through fourth detection units  41  to  44 , a mount  45  made of metal, a cover panel  46  made of carbon, and a slitted panel  47  made of metal. 
     (2-6-1) Detection Units 
     The first through fourth detection units  41  to  44  are a plurality of units with the same configuration, each of which has a ceramic substrate  51 , a detection main body  52 , and a scintillator  53 . 
     The ceramic substrate  51  is a substrate made of a ceramic which supports the detection main body  52  and supports the scintillator  53  via the detection main body  52 , and the ceramic substrate has higher hardness and resists deformation better than would a plastic substrate. 
     The detection main body  52  is a CMOS image sensor, including a plurality of elements  60  which are light-receiving elements. The plurality of elements  60  are disposed in a straight line in the forward-backward direction (the Y direction). The elements  60  are disposed on the scintillator  53 , i.e., on the side of the scintillator  53  that faces the X-ray radiation device  13 , as shown in  FIG. 6 . The elements  60  are sensitive to X-rays in a predetermined energy band and visible light rays in a predetermined wavelength band, and the elements generate detection signals. 
     The detection main body  52  has a fixed part  52   a  fixed to an end part of the ceramic substrate  51 , and an overhanging part  52   b  protruding leftward from a left-side end face  51   c  of the ceramic substrate  51 , as shown in  FIG. 6 . The plurality of elements  60  receive light in the overhanging part  52   b.  The elements  60  are connected to respective circuits placed on the ceramic substrate  51 . 
     The plurality of elements  60  are positioned vertically below the X-ray radiation device  13 , and X-rays spreading out in a fan shape along a vertical plane from the X-ray radiation device  13 , as shown in  FIG. 2 , enter the elements  60  from directly above, as shown in  FIG. 6 . 
     The scintillator  53  is a thin panel-shaped phosphor extending in the forward-backward direction (the Y direction) in which the plurality of elements  60  are aligned, and is bonded to the lower face of the detection main body  52 . The scintillator  53  emits visible light rays of a predetermined wavelength band by absorbing X-rays of an energy band higher than the predetermined energy band. The visible light rays emitted from the scintillator  53  are detected by the elements  60  positioned directly above. The elements  60  detect these visible light rays and X-rays of the predetermined energy band, convert the intensities thereof to electric signals, and output these signals as detection signals to the control computer  20 . 
     The first through fourth detection units  41  to  44  are aligned in the forward-backward direction (the Y direction) in the line sensor assembly  14  so that the detection main body  52  and the scintillator  53  of one of the first through fourth detection units  41  to  44  are aligned without gaps with the detection main body  52  and scintillator  53  of one of the adjacent first through fourth detection units  41  to  44  (for example, the second detection unit  42  adjacent to the first detection unit  41 ), as shown in  FIGS. 9 and 10A . Specifically, in each of the first through fourth detection units  41  to  44 , the forward-backward directional length of the ceramic substrate  51 , the forward-backward directional length of the detection main body  52 , and the forward-backward directional length of the scintillator  53  are equal. The detection main body  52  and the scintillator  53  are aligned without gaps in the border between two adjacent detection units, by aligning the first through fourth detection units  41  to  44  as shown in  FIG. 9 , so that the front and back end faces of a ceramic substrate  51  are in contact with the front and back end faces of the ceramic substrates  51  of the adjacent first through fourth detection units  41  to  44 . 
     (2-6-2) Mount 
     The metal mount  45  is a support member which supports the first through fourth detection units  41  to  44 . The first through fourth detection units  41  to  44 , and the hereinafter-described cover panel  46  and slitted panel  47 , are placed on the metal mount  45 , and are sandwiched by the mount  45  and a fixing panel  48 , as shown in  FIGS. 5, 6 , etc. 
     On the upper part of the mount  45  are formed a groove  45   a  extending in the forward-backward direction (the Y direction), and step side faces  45   b,    45   c,  as shown in  FIGS. 7A, 7B , etc. The groove  45   a  forms an accommodating space for the detection main bodies  52  and the scintillators  53  of the first through fourth detection units  41  to  44 , as shown in  FIG. 6 . The step side face  45   b  extends in the forward-backward direction (the Y direction) and faces to the left. The step side face  45   b  is in contact with right-side end faces  51   b  of the ceramic substrates  51  of the first through fourth detection units  41  to  44 , as shown in  FIGS. 10A and 10B . The step side face  45   c  extends to leftward along the left-right direction (the X direction) from the front-side end of the step side face  45   b,  and faces rearward. The step side face  45   c  is in contact with a front-side end face  51   d  of the first detection unit  41 , as shown in  FIG. 10A . 
     (2-6-3) Cover Panel 
     The cover panel  46  is a panel-shaped member covering the plurality of elements  60  of the four first through fourth detection units  41  to  44  from above. The cover panel  46 , which is made of carbon, has lower X-ray absorptivity than the ceramic substrate  51 . 
     The cover panel  46  is placed on the mount  45 , and the height position of the upper face of the cover panel is level with the position of the upper faces of the ceramic substrates  51  of the first through fourth detection units  41  to  44  (see  FIGS. 5 and 6 ). The cover panel  46  is configured from a main body part  46   a  extending lengthwise in the forward-backward direction (the Y direction), and a protruding part  46   b  protruding rightward from a rear end part of the main body part  46   a,  as shown in  FIG. 9  etc. A right-side end face  46   c  of the main body part  46   a  of the cover panel  46  is in contact with the left-side end faces  51   c  of the ceramic substrates  51  of the four first through fourth detection units  41  to  44 . 
     The right-side end face  46   c  of the main body part  46   a  of the cover panel  46  is in contact with the left-side end faces  51   c  of the ceramic substrates  51 , and the step side face  45   b  of the mount  45  described above is in contact with the right-side end faces  51   b  of the ceramic substrates  51 , whereby the first through fourth detection units  41  to  44  are positioned with respect to the left-right direction (the X direction). 
     Furthermore, a front side face  46 d of the protruding part  46   b  of the cover panel  46  is in contact with a rear-side end face  51 e of the fourth detection unit  44 , and the step side face  45   c  of the mount  45  described above is in contact with the front-side end face  51   d  of the first detection unit  41  as shown in  FIG. 10A , whereby the first through fourth detection units  41  to  44  are positioned with respect to the forward-backward direction (the Y direction). 
     (2-6-4) Slitted Panel 
     The slitted panel  47  is a metal plate disposed so as to cover, from above, the cover panel  46  and the ceramic substrates  51  of the left-to-right aligned first through fourth detection units  41  to  44  described above. One slitted panel  47  is placed on top of four ceramic substrates  51  and one cover panel  46 , and the slitted panel presses these components down on the upper face of the mount  45 . Specifically, the first through fourth detection units  41  to  44  are sandwiched between one mount  45  and one slitted panel  47 . 
     One long slit  47   a  extending in the forward-backward direction is formed in the slitted panel  47 , directly above the plurality of elements  60  extending continuously in the forward-backward direction (the Y direction) across the first through fourth detection units  41  to  44  (see  FIGS. 5 and 6 ). X rays radiated from the X-ray radiation device  13  pass through the slit  47   a  and through the carbon cover panel  46  to be incident on the elements  60  of the detection main bodies  52 . 
     (3) Inspection of Foreign Material Presence/Absence by Control Computer 
     (3-1) X-Ray Image Production 
     When goods G pass through the X-ray radiation area (refer to the hatched portion in  FIG. 2 ), the X-ray image production part  21   a  of the control computer  20  acquires fluoroscopic signals (see  FIG. 3 ), which are detection signals from the elements  60  of the line sensor assembly  14  in a brief time interval, and uses these fluoroscopic signals as a basis to produce an X-ray image of the goods G Specifically, the X-ray image production part  21   a  takes the difference between the output of the elements  60  when there are no foreign materials and the output of the elements  60  when there are foreign materials, and from this difference produces an X-ray image of the goods G 
     (3-2) Determination of Foreign Material Presence/Absence 
     From the obtained X-ray image, the foreign material presence/absence inspection part  21   b  of the control computer  20  determines whether or not the goods G have been contaminated by foreign materials. There are several determination methods, but one example is to set a reference level (a threshold value) in accordance with the general thickness of the detected objects, and to determine that foreign materials have contaminated the goods G when the image is darker than the reference level. As a result of the determinations by the determination methods, if there is determined to be foreign material contamination in the determination of any method, the foreign material presence/absence inspection part  21   b  determines that foreign materials have contaminated the goods G In this case, the control computer  20  puts an inferior product display on the LCD monitor  30  and sends a sorting command to the sorting apparatus  70 . 
     (4) Assembly Procedure for Line Sensor Assembly 
     Next, some of the assembly steps for the line sensor assembly are described with reference to  FIGS. 7A, 7B to 10A, and 10B . 
     The first detection unit  41  is first placed on the upper face of the mount  45  shown in  FIGS. 7A and 7B . The first detection unit  41  is placed on the upper face of the mount  45  so that the right-side end face  51   b  of the ceramic substrate  51  is near the step side face  45   b  of the mount  45 , and the front-side end face  51   d  of the ceramic substrate  51  is near the step side face  45   c  of the mount  45 , as shown in  FIGS. 8A and 8B . 
     Next, the other detection units are placed in order on the mount  45  so that the second detection unit  42  is aligned with the rear side of the first detection unit  41 , the third detection unit  43  is aligned with the rear side of the second detection unit  42 , and the fourth detection unit  44  is aligned with the rear side of the third detection unit  43 . 
     When the first through fourth detection units  41  to  44  are then placed on the mount  45  so that the right-side end faces  51   b  of the ceramic substrates  51  of the first through fourth detection units  41  to  44  come to be in close proximity to the step side face  45   b  of the mount  45  as shown in  FIG. 9 , the cover panel  46  is next placed on the mount  45 . 
     After the cover panel  46  has been placed on the mount  45 , the cover panel  46  is pushed on the front and right sides. The ceramic substrates  51  of the first through fourth detection units  41  to  44  are thereby pushed on the front and right sides by the cover panel  46 . The right-side end faces  51   b  of the ceramic substrates  51  of the first through fourth detection units  41  to  44  then come to be in contact with the step side face  45   b  of the mount  45 , and the front-side end face  51   d  of the first detection unit  41  comes to be in contact with the step side face  45   c  of the mount  45 . This is the regular planar positioning of the first through fourth detection units  41  to  44 , and in this state, the cover panel  46  is screwed to the mount  45 . The screwing may be accomplished by placing the slitted panel  47  on top and then securing both the slitted panel  47  and the cover panel  46  to the mount  45 . 
     (5) Characteristics of X-Ray Inspecting Apparatus 
     (5-1) 
     In the X-ray inspecting apparatus  10 , because the plurality of elements  60  are disposed on the side of the scintillator  53  that faces the X-ray radiation device  13  in the line sensor assembly  14 , X-rays are directly incident on the elements  60 , and X-rays of a predetermined energy band are detected by the elements  60 . X-rays of an energy band higher than the predetermined energy band are also detected by the elements  60  because these X-rays are converted to visible light rays of a predetermined wavelength band by the scintillator  53 . Therefore, the first through fourth detection units  41  to  44  are able to detect X-rays of a broad energy band. 
     (5-2) 
     In the X-ray inspecting apparatus  10 , a configuration is used in which the first through fourth detection units  41  to  44  are aligned in the line sensor assembly  14 , but if a configuration were to be used in which all of the elements  60  were included on one unit, the unit would be larger and manufacturing costs would rise for reasons such as assembly being more difficult. 
     However, because the X-ray inspecting apparatus  10  employs a configuration in which the first through fourth detection units  41  to  44  are aligned in the forward-backward direction, the yield of each of the first through fourth detection units  41  to  44  is improved, the apparatus is easier to assemble, and manufacturing costs are reduced. 
     (5-3) 
     In the X-ray inspecting apparatus  10 , the first through fourth detection units  41  to  44 , in which the plurality of elements  60  are disposed on the sides of the scintillators  53  that face the X-ray radiation device  13 , are aligned in the forward-backward direction, which is the longitudinal direction of the detection units, but depending on the manner of alignment, there is a risk that the elements  60  and the scintillators  53  would not be continuous in the borders of adjacent units. 
     However, in the X-ray inspecting apparatus  10 , the first through fourth detection units  41  to  44  are aligned in the forward-backward direction so that the detection main bodies  52  and the scintillators  53  of the first through fourth detection units  41  to  44  are aligned without gaps with the detection main bodies  52  and the scintillators  53  of the adjacent first through fourth detection units  41  to  44 . Therefore, the continuity of the elements  60  and the scintillators  53  is ensured, and there is no problem of X-ray sensitivity being lowered in any section along the forward-backward direction. 
     (5-4) 
     In the X-ray inspecting apparatus  10 , the ceramic substrates  51 , which have higher hardness than plastic substrates, are employed as the bases supporting the detection main bodies  52  and the scintillators  53  in the first through fourth detection units  41  to  44  of the line sensor assembly  14 . Therefore, there are no situations in which the ceramic substrates  51  deform to compromise the continuity of the elements  60  and the scintillators  53  after the ceramic substrates  51  of adjacent first through fourth detection units  41  to  44  have been brought into contact and the relative positions thereof have been fixed. 
     (5-5) 
     In the X-ray inspecting apparatus  10 , the forward-backward directional length of the ceramic substrate  51 , the forward-backward directional length of the detection main body  52 , and the forward-backward directional length of the scintillator  53  are equal in each of the first through fourth detection units  41  to  44  of the line sensor assembly  14 . The first through fourth detection units  41  to  44  are aligned sequentially so that the front and rear end faces of one ceramic substrate  51  is in contact with the front and rear end faces of the ceramic substrates  51  of adjacent first through fourth detection units  41  to  44 , as shown in  FIG. 9 . The scintillators  53  of the first through fourth detection units  41  to  44  and the elements  60  of the detection main bodies  52  are thereby naturally aligned without gaps in the borders of the first through fourth detection units  41  to  44 . Thus, the assembly steps are simplified, and manufacturing costs fall. 
     (5-6) 
     In the X-ray inspecting apparatus  10 , in all of the first through fourth detection units  41  to  44  of the line sensor assembly  14 , the elements  60  are disposed on the overhanging parts  52   b  protruding leftward from the left-side end faces  51   c  of the ceramic substrates  51 . Therefore, even in a line sensor assembly  14  in which the X-ray radiation device  13 , the elements  60 , and the scintillators  53  are aligned from the top downward, it is possible to achieve a state in which the ceramic substrates  51  are not located between the X-ray radiation device  13  and the elements  60  (see  FIG. 6 ). 
     Specifically, if the elements  60  were to be included on the fixed parts  52   a  of the detection main bodies  52  fixed to the ceramic substrates  51 , the ceramic substrates  51 , the elements  60 , and the scintillators  53  would be aligned from the top downward, and X-rays would first pass through the ceramic substrates  51  should X-rays be caused to be incident not from the scintillator  53 -side but from the element  60 -side. Ceramic substrates generally have higher X-ray absorptivity than plastic substrates, and the output of the X-ray radiation device  13  would need to be increased in order to maintain detection sensitivity. 
     In contrast, due to the elements  60  being disposed on and made to receive light on the overhanging parts  52   b  of the detection main bodies  52  in the X-ray inspecting apparatus  10 , it is possible to yield a line sensor assembly  14  that can detect X-rays over a broad energy band with low output, in which X-rays are directly incident on the elements  60  from the X-ray radiation device  13  and X-rays that have passed through the elements  60  are incident on the scintillators  53 . 
     (5-7) 
     In the X-ray inspecting apparatus  10 , because the elements  60  are disposed on the overhanging parts  52   b  of the detection main bodies  52  in the line sensor assembly  14 , there is a risk that dust will collect on and adhere to the tops of the elements  60  if no countermeasures are taken. In view of this, in the X-ray inspecting apparatus  10 , the elements  60  are covered from above by the cover panel  46 , and loss of sensitivity of the elements  60  due to dust is suppressed. Because a carbon cover panel  46  is employed, which has a lower rate of X-ray absorption than the ceramic substrates  51 , detection sensitivity can be maintained without increasing the output of the X-ray radiation device  13 . 
     (5-8) 
     In the X-ray inspecting apparatus  10 , the mount  45  supporting the first through fourth detection units  41  to  44  and the cover panel  46  covering the plurality of elements  60  from above in the line sensor assembly  14  both have a contact face that comes into contact with the side faces of the ceramic substrates  51  of the first through fourth detection units  41  to  44 . Specifically, the step side face  45   b  of the mount  45  comes into contact with the right-side end faces  51   b  of the ceramic substrates  51 , and the right-side end face  46   c  of the main body part  46   a  of the cover panel  46  comes into contact with the left-side end faces  51   c  of the ceramic substrates  51 . The ceramic substrates  51  of the first through fourth detection units  41  to  44  are thereby positioned with respect to the left-right direction (the X direction), whereby the scintillators  53  and the elements  60  of the detection main bodies  52  supported on the ceramic substrates  51  are also accurately positioned. Therefore, in the X-ray inspecting apparatus  10 , the scintillators  53  and detection main bodies  52  of two adjacent detection units are aligned without gaps, and the continuity of the elements  60  and the scintillators  53  is ensured. 
     (5-9) 
     In the line sensor assembly  14  of the X-ray inspecting apparatus  10 , the state of X-ray detection stabilizes because X-rays that have passed through the slit  47   a  in the slitted panel  47  enter the elements  60  and the scintillators  53 . The first through fourth detection units  41  to  44  are held by being vertically sandwiched between the slitted panel  47  and the mount  45 . Therefore, with the scintillators  53  and the detection main bodies  52  aligned without gaps, the first through fourth detection units  41  to  44  can be maintained as being reliably supported on the mount  45 .