Belt drive mechanism and x-ray inspection device

Abstract

To provide a belt drive mechanism capable of suppressing electrostatic charging, and an X-ray inspection device equipped with such a belt drive mechanism.SOLUTION: A belt drive mechanism 1 includes a plurality of rollers 10 and a belt 20 spanning the plurality of rollers 10. The belt 20 has a contact surface 22 that contacts the multiple rollers 10. The contact surface 22 includes a conductive region 25 having a surface resistivity of 1×104 Ω / sq. or more and 1×1011 Ω / sq. or less.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a belt drive mechanism and an X-ray inspection apparatus. [Background technology]

[0002] Belt drive mechanisms that include multiple rollers and a belt stretched over the multiple rollers are known (see, for example, Patent Documents 1 and 2). In such belt drive mechanisms, the belt moves as the multiple rollers rotate, and articles placed on the belt are conveyed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-174483 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-006064 Summary of the Invention [Problem to be solved by the invention]

[0004] In the belt drive mechanism described above, as the roller rotates, contact and separation between the roller surface and the belt surface occurs repeatedly, generating electric charges. The generated electric charges are charged as static electricity on the roller and the belt. The charged static electricity may propagate to electronic components of the device equipped with the belt drive mechanism, causing malfunctions.

[0005] An object of the present disclosure is to provide a belt drive mechanism capable of suppressing static electricity buildup, and an X-ray inspection apparatus including such a belt drive mechanism. [Means for solving the problem]

[0006] The belt drive mechanism of the present disclosure includes: [1] "a plurality of rollers; and a belt wound around the plurality of rollers, the belt having a contact surface that contacts the plurality of rollers, and the contact surface has a diameter of 1×10 4 Ω / sq. or more 1×10 11 "A belt drive mechanism including a conductive area having a surface resistivity of Ω / sq. or less."

[0007] In the belt drive mechanism, the belt has a contact surface that contacts a plurality of rollers, and the contact surface is 1×10 4 Ω / sq. or more 1×10 11 The belt drive mechanism includes a conductive area with a surface resistivity of Ω / sq. or less. This allows the generated charge to be widely dispersed in the conductive area and easily discharged into the air, even if the charge is generated by the rotation of the roller. Therefore, the belt drive mechanism can suppress static electricity buildup.

[0008] The belt drive mechanism of the present disclosure may be [2] "the belt drive mechanism according to [1], wherein the conductive region is a region to which a conductive sheet is attached." In this case, a highly durable conductive region can be formed with a simple configuration.

[0009] The belt drive mechanism of the present disclosure may be [3] "the belt drive mechanism according to [2]," in which the conductive sheet is a tape made of aluminum. In this case, a highly durable conductive region can be formed with a simple configuration.

[0010] The belt drive mechanism of the present disclosure may be [4] "the belt drive mechanism according to [1]," in which the conductive region is a region to which a powdery conductive material is attached." In this case, the conductive region can be formed with a simple configuration. Furthermore, since the powdery conductive material such as metal powder that constitutes the conductive region is difficult to peel off, static electricity can be more reliably suppressed.

[0011] The belt drive mechanism of the present disclosure may be [5] "the belt drive mechanism according to [1]," in which the conductive region is a region coated with a liquid or gel-like conductive material." In this case, the conductive region can be formed with a simple configuration. Furthermore, since the liquid or gel-like conductive material, such as conductive paste or conductive grease, that constitutes the conductive region is difficult to peel off, static electricity can be more reliably suppressed.

[0012] The belt drive mechanism of the present disclosure may be [6] "the belt drive mechanism according to [1]," in which the conductive region is a region to which an antistatic agent is attached." In this case, the conductive region can be formed with a simple configuration. Furthermore, since the antistatic agent constituting the conductive region is less likely to peel off, static electricity can be more reliably suppressed.

[0013] The belt drive mechanism of the present disclosure may be [7] "the belt drive mechanism according to [6]," in which the antistatic agent is a surfactant. In this case, the conductive region can be formed with a simple configuration. Furthermore, since the surfactant constituting the conductive region is less likely to peel off, static electricity can be more reliably suppressed.

[0014] The belt drive mechanism of the present disclosure may be [8] "the belt drive mechanism according to any one of [1] to [7], wherein the conductive region is formed across the contact surface from one end to the other in the width direction of the belt." In this case, a large area of ​​the conductive region can be secured on the contact surface, and static electricity can be more reliably suppressed.

[0015] The belt drive mechanism of the present disclosure may be [9] "the belt drive mechanism according to any one of [1] to [8], wherein the contact surface has a region made of the conductive region and a region not including the conductive region." In this case, the conductive region can be formed more easily than when the conductive region is formed over the entire contact surface.

[0016] The belt drive mechanism of the present disclosure may be

[10] "the belt drive mechanism according to any one of [1] to [9], wherein the contact surface includes a plurality of conductive regions, each of which is the conductive region, and the plurality of conductive regions are positioned apart from one another in an extension direction of the belt that intersects with the width direction of the belt." In this case, the conductive regions can be formed more easily than when the conductive regions are formed on the entire contact surface.

[0017] The belt drive mechanism of the present disclosure may be

[11] "the belt drive mechanism according to any one of [1] to

[10] , wherein the contact surface includes a pair of conductive regions, each of which is the conductive region, and the pair of conductive regions are positioned apart from each other to sandwich a central region of the contact surface in the width direction of the belt." In this case, for example, when the belt drive mechanism is applied to an X-ray inspection device, it is possible to prevent X-rays irradiated to an object to be inspected from being blocked by the conductive regions. Therefore, X-ray inspection can be performed appropriately.

[0018] The belt drive mechanism of the present disclosure may be

[12] "the belt drive mechanism according to any one of [1] to

[11] , wherein the contact surface includes at least one conductive region, each of which is the conductive region, and the total area of ​​the at least one conductive region is 30% or more of the entire area of ​​the contact surface." In this case, a large area of ​​the conductive region can be ensured on the contact surface, thereby more reliably suppressing static electricity buildup.

[0019] The X-ray inspection device of the present disclosure is

[13] "an X-ray inspection device comprising a belt drive mechanism according to any one of [1] to

[12] , an X-ray irradiation unit that irradiates X-rays onto an object being transported by the belt, and an X-ray detection unit that detects X-rays that have passed through the object."

[0020] According to the above-described X-ray inspection device, for the reasons described above, it is possible to suppress static electricity buildup in the belt drive mechanism. By using such a belt drive mechanism, problems caused by the propagation of static electricity are suppressed, and X-ray inspection can be performed appropriately.

[0021] The X-ray inspection device of the present disclosure may be

[14] "the X-ray inspection device according to

[13] , in which the belt is positioned so as to surround the plurality of rollers, and the X-ray detection unit is arranged inside the belt." In this case, the X-ray inspection device can be made smaller than a configuration in which the X-ray detection unit is arranged outside the belt.

[0022] The X-ray inspection device of the present disclosure may be

[15] "the X-ray inspection device according to

[13] or

[14] , wherein the contact surface includes a pair of conductive regions, each of which is the conductive region, and the pair of conductive regions are positioned apart from each other to sandwich a central region of the contact surface in the width direction of the belt." In this case, it is possible to prevent the X-rays irradiated to the object to be inspected from being blocked by the conductive regions. Therefore, X-ray inspection can be performed appropriately. [Effects of the Invention]

[0023] According to the present disclosure, it is possible to provide a belt drive mechanism capable of suppressing static electricity buildup, and an X-ray inspection apparatus including such a belt drive mechanism. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a configuration diagram of an X-ray inspection apparatus including a belt drive mechanism according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the belt driving mechanism shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view of the belt shown in FIG. [Figure 4] FIG. 2 is a plan view showing the contact surface of the belt shown in FIG. [Figure 5] FIG. 4 is a cross-sectional view of a belt according to a second embodiment. [Figure 6] FIG. 10 is a cross-sectional view of a belt according to a third embodiment. [Figure 7] 10 is a table showing the measurement results of the charging voltage on a belt made of rubber. [Figure 8]10 is a table showing the results of measuring the charging voltage on a belt made of polyurethane. [Figure 9] 1 is a graph showing the relationship between the application area of ​​the antistatic agent and the maximum charging voltage of the belt. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted. [Configuration and operation of X-ray inspection equipment]

[0026] The configuration of an X-ray inspection apparatus 100 according to a first embodiment will be described with reference to FIGS. 1 and 2. The X-ray inspection apparatus 100 is an apparatus for inspecting an object. The X-ray inspection apparatus 100 inspects the object using X-rays while transporting the object to be inspected. The inspection of the object may be, for example, an inspection for the presence of foreign matter or an inspection for defects. The X-ray inspection apparatus 100 includes a belt drive mechanism 1, an X-ray irradiation unit 2, and an X-ray detection unit 3.

[0027] The belt drive mechanism 1 is a device for conveying articles, such as a belt conveyor. The belt drive mechanism 1 includes a plurality of rollers (pulleys) 10, a belt 20, and a motor 30. In this example, the belt drive mechanism 1 includes a pair of rollers 10. Each roller 10 has a central axis C. In this example, the rollers 10 have a substantially cylindrical outer shape extending along the central axis C. The shape of the rollers 10 is not limited, and may be, for example, a disk shape. The rollers 10 have a contact surface (second contact surface) 11 that contacts the belt 20. The contact surface 11 extends so as to surround the central axis C. The contact surface 11 extends in an annular shape when viewed in a direction along the central axis C. The contact surface 11 may be formed with teeth (not shown) that mesh with teeth (a plurality of protrusions 24 described below) formed on the belt 20. The rollers 10 may be formed of a metal such as aluminum, iron, or stainless steel. When the roller 10 is made of aluminum, the surface of the roller 10 may be anodized. The roller 10 may also be made of a material other than metal, such as resin.

[0028] The belt 20 is stretched over a plurality of rollers 10. In this example, the belt 20 is an endless belt formed in a loop. The belt 20 is positioned so as to surround the plurality of rollers 10. The belt 20 has a placement surface 21 on which an article is placed, and a contact surface (first contact surface) 22 that comes into contact with the plurality of rollers 10. The placement surface 21 is the outer peripheral surface (surface located on the outside) of the belt 20. The contact surface 22 is the inner peripheral surface (surface located on the inside) of the belt 20. The contact surface 22 is located on the opposite side of the placement surface 21 in the thickness direction of the belt 20. The contact surface 22 comes into contact with the contact surface 11 of each roller 10.

[0029] The motor 30 is connected to one of the pair of rollers 10. The motor 30 rotates the connected roller 10 around a central axis C. The motor 30 may have an integrated circuit (IC) that controls the operation of the motor 30 (for example, the rotation speed and rotation direction of the rotation shaft).

[0030] The X-ray irradiator 2 is an X-ray source that irradiates X-rays onto an object 4, which is an inspection target placed on the placement surface 21. The X-ray detector 3 is a device that detects the X-rays emitted from the X-ray irradiator 2. In this example, the X-ray detector 3 is a camera that captures an X-ray transmission image of the object 4, such as an X-ray line sensor camera. The X-ray detector 3 acquires measurement data for generating the X-ray transmission image. The X-ray detector 3 has a scintillator that emits scintillation light when X-rays are incident on it, and a measuring device that acquires measurement data by detecting the scintillation light.

[0031] In the X-ray inspection device 100, when the motor 30 is driven, the rollers 10 connected to the motor 30 rotate around the central axis C. As a result, the belt 20 in contact with the rollers 10 moves in the conveying direction (the direction of the arrow in FIG. 1 ), and the remaining rollers 10 rotate around the central axis C as the belt 20 moves. An object 4 placed on the placement surface 21 of the belt 20 moves in the conveying direction together with the belt 20. The X-ray irradiation unit 2 irradiates X-rays onto the object 4 being conveyed by the belt drive mechanism 1. The irradiated X-rays pass through the object 4 and then enter the X-ray detection unit 3. The X-ray detection unit 3 acquires measurement data based on the incident X-rays. The X-ray detection unit 3 is communicatively connected to an external processing device via a cable or the like. The processing device is a computer device that generates an X-ray transmission image of the object 4 based on the measurement data output from the measuring device of the X-ray detection unit 3. The processing device acquires an inspection result of the object 4 based on the generated X-ray transmission image. [Configuration of belt drive mechanism 1]

[0032] The configuration of the belt driving mechanism 1 will be described in more detail with reference to Figures 1, 2, 3, and 4. As shown in Figure 3, the belt 20 has a main body 23 and a plurality of protrusions 24 formed integrally with the main body 23. The main body 23 extends in an annular shape so as to surround the plurality of rollers 10. The main body 23 has a surface 23a and a surface 23b. The surface 23a is the outer peripheral surface of the main body 23 and forms the mounting surface 21 of the belt 20. In this example, the surface 23a (mounting surface 21) is formed flat. The surface 23b is the inner peripheral surface of the main body 23 and is located on the opposite side to the surface 23a in the thickness direction of the main body 23. In this example, the surface 23b is formed flat.

[0033] The plurality of protrusions 24 are formed on the surface 23b of the main body 23. The plurality of protrusions 24 are positioned apart from one another in the extending direction of the belt 20. The extending direction of the belt 20 is a direction intersecting with the width direction of the belt 20. In this example, the width direction of the belt 20 is a direction along the central axis C of the roller 10, and the extending direction of the belt 20 is a direction perpendicular to the width direction of the belt 20.

[0034] Each of the protrusions 24 protrudes from the surface 23b toward the inside of the belt 20. As shown in FIG. 4, each of the protrusions 24 extends along the width direction of the belt 20. For ease of explanation, FIG. 4 shows only some of the protrusions 24, and the other protrusions 24 are omitted. Each of the protrusions 24 is formed continuously from one end of the surface 23b to the other end in the width direction of the belt 20. The belt 20 (main body 23 and protrusions 24) may be made of, for example, rubber or a resin material such as polyurethane. When the belt 20 is made of rubber, a tooth cloth that suppresses the generation of rubber powder may be formed on the surface 23b of the main body 23 and the surfaces 24a of the protrusions 24.

[0035] 3 and 4, the contact surface 22 of the belt 20 includes a plurality of conductive areas 25. Each conductive area 25 has a diameter of 1×10 4 Ω / sq. or more 1×10 11The conductive region 25 is a region having a surface resistivity of Ω / sq. or less. The surface resistivity of the conductive region 25 is lower than the surface resistivity of other regions that are not the conductive region 25. The surface resistivity is measured by measuring the resistance using a surface resistance meter or a tester in resistance mode.

[0036] The multiple conductive regions 25 are positioned apart from one another in both the width direction of the belt 20 (direction X shown in FIG. 4) and the extension direction of the belt 20 (direction Y shown in FIG. 4) which intersects with the width direction of the belt 20. Between adjacent conductive regions 25 in the width direction or extension direction of the belt 20, there are regions which do not include a conductive region 25. That is, the contact surface 22 has a region A1 which is made up of a conductive region 25 and a region A2 which does not include a conductive region 25. The multiple conductive regions 25 are not formed over the entire contact surface 22, but are formed partially on the contact surface 22.

[0037] The contact surface 22 includes a central region 27 and a pair of outer regions 28. The central region 27 is a region of the contact surface 22 that includes the center of the belt 20 in the width direction. The central region 27 may be a region that overlaps, in the thickness direction of the belt 20, with a region on the placement surface 21 of the belt 20 where the article 4 is placed. The central region 27 may be a region located in the middle in the width direction of the belt 20 when the contact surface 22 is divided into three regions with equal widths along the width direction of the belt 20. The pair of outer regions 28 may be regions located on either side of the central region 27.

[0038] The plurality of conductive regions 25 are not formed in the central region 27, but are formed in each of the pair of outer regions 28. The plurality of conductive regions 25 includes a plurality of sets of two corresponding conductive regions 25 (pairs of conductive regions 25). The two corresponding conductive regions 25 are positioned apart from each other in the width direction of the belt 20, sandwiching the central region 27 therebetween. For example, in the example shown in FIG. 4, a pair of conductive regions 251 and 252 among the plurality of conductive regions 25 are positioned apart from each other, sandwiching the central region 27 therebetween.

[0039] In this example, each conductive region 25 is an area to which a conductive sheet 26 is attached. The conductive sheet 26 is attached to the surface 23b of the main body 23 and the surface 24a of the protrusion 24. The conductive sheet 26 may be, for example, a sheet containing metal (metal sheet). Furthermore, the material of the conductive sheet 26 is not limited to metal as long as it is conductive, and may be a material containing graphite, carbon nanotubes (CNTs), or carbon. The conductive sheet 26 may also be a composite material composed of a conductive substance and other substances such as rubber or resin. The metal sheet may be a tape including a metal foil and an adhesive layer laminated on the metal foil. The metal foil is attached to the surface 23b and the surface 24a via the adhesive layer. In this example, the conductive sheet 26 is a tape made of aluminum (aluminum tape). The aluminum tape includes aluminum foil and an adhesive layer laminated on the aluminum foil. The metal included in the conductive sheet 26 is not limited to aluminum, but may be, for example, copper, silver, stainless steel, iron, nickel, lead, zinc, etc. The conductive sheets 26 may have their surfaces plated with a different metal such as tin or nickel. In this example, each conductive sheet 26 is formed into a rectangular shape in a plan view. The width of the conductive sheet 26 in the extension direction of the belt 20 is smaller than the width of the conductive sheet 26 in the width direction of the belt 20.

[0040] A plurality of conductive sheets 26 are attached to the surface 23b of the main body 23 and the surface 24a of the protrusions 24. Each conductive sheet 26 has a surface 26a. The surface 26a is the surface of the conductive sheet 26 located opposite the contact surface with the surfaces 23b and 24a. The surface 26a of the conductive sheet 26 forms part of the contact surface 22. The surface 26a contacts the contact surface 11 of the roller 10. In this example, the contact surface 22 is composed of the surface 26a of the conductive sheet 26, an area on the surface 24a of the protrusions 24 where the conductive sheet 26 is not attached, and an area on the surface 23b of the main body 23 where the conductive sheet 26 is not attached. The total area of ​​the plurality of conductive regions 25 (surfaces 26a) may be 10% or more, 20% or more, 30% or more, or 50% or more of the entire area of ​​the contact surface 22. [Action and effect]

[0041] In the belt driving mechanism 1, the belt 20 has a contact surface 22 that contacts the plurality of rollers 10. The contact surface 22 has a diameter of 1×10 4 Ω / sq. or more 1×10 11 The belt driving mechanism 1 includes a conductive region 25 having a surface resistivity of Ω / sq. or less. As a result, even if an electric charge is generated by the rotation of the roller 10, the generated electric charge is widely dispersed in the conductive region 25 and easily discharged into the air. Therefore, the belt driving mechanism 1 can suppress static electricity buildup.

[0042] The conductive region 25 is a region to which the conductive sheet 26 is attached. This allows for the formation of a highly durable conductive region 25 with a simple configuration. For example, even if the conductive sheet 26 is in contact with the rotating roller 10 for a long period of time, the conductive portions of the conductive sheet 26 (e.g., metal portions) are unlikely to be removed, and therefore the surface resistivity can be maintained within the above range.

[0043] The conductive sheet 26 is a tape made of aluminum, which allows the formation of a highly durable conductive region 25 with a simple structure.

[0044] The contact surface 22 has an area A1 made up of the conductive region 25 and an area A2 that does not include the conductive region 25. This makes it easier to form the conductive region 25 than when a conductive region is formed over the entire contact surface 22.

[0045] The contact surface 22 includes a plurality of conductive regions 25. The plurality of conductive regions 25 are positioned apart from one another in the extension direction of the belt 20, which intersects with the width direction of the belt 20. This makes it easier to form the conductive regions 25 than when conductive regions are formed over the entire contact surface 22.

[0046] The contact surface 22 includes a pair of conductive regions 25 (e.g., conductive regions 251 and 252). The pair of conductive regions 25 are positioned apart from each other on either side of a central region 27 of the contact surface 22 in the width direction of the belt 20. This prevents the conductive region 25 (conductive sheet 26) from blocking the X-rays irradiated onto the object 4 to be inspected. This allows for proper X-ray inspection.

[0047] The total area of ​​the plurality of conductive regions 25 may be 30% or more of the entire area of ​​the contact surface 22. In this case, a large area of ​​the conductive regions 25 can be secured on the contact surface 22, thereby more reliably suppressing static electricity buildup.

[0048] The X-ray inspection apparatus 100 includes a belt drive mechanism 1, an X-ray irradiation unit 2, and an X-ray detection unit 3. For the reasons described above, the X-ray inspection apparatus 100 can suppress static electricity buildup in the belt drive mechanism 1. By using such a belt drive mechanism 1, problems caused by the propagation of static electricity are suppressed, allowing X-ray inspection to be performed appropriately. For example, if static electricity builds up on the roller 10 or the belt 20, the static electricity may propagate to other electronic devices (such as an IC that controls the motor 30 and the X-ray detection unit 3) arranged nearby, potentially causing problems. However, the X-ray inspection apparatus 100 suppresses static electricity buildup. Therefore, problems caused by the propagation of static electricity can be suppressed.

[0049] The belt 20 is positioned so as to surround the plurality of rollers 10. The X-ray detection unit 3 is disposed inside the belt 20. This allows the X-ray inspection device 100 to be made more compact than in a configuration in which the X-ray detection unit 3 is disposed outside the belt 20. [Second embodiment]

[0050] The configuration of the belt driving mechanism according to the second embodiment will be described with reference to Fig. 5. The belt driving mechanism according to the second embodiment may be used in place of the belt driving mechanism 1 in the X-ray inspection apparatus 100 according to the first embodiment. The belt driving mechanism according to the second embodiment differs from the belt driving mechanism 1 according to the first embodiment in the shape of the conductive region formed on the belt 20. As shown in Fig. 5, the contact surface 22 of the belt 20 according to the second embodiment includes a pair of conductive regions 25A. The conductive region 25A has a size of 1 x 10 4 Ω / sq. or more 1×10 11 The conductive region 25A is a region having a surface resistivity of Ω / sq. or less. The surface resistivity of the conductive region 25A is measured by the same method as that for the surface resistivity of the conductive region 25.

[0051] Each conductive region 25A is formed along the extension direction of the belt 20. Each conductive region 25A is formed continuously in an annular shape along the extension direction of the belt 20. A pair of conductive regions 25A are positioned apart from each other on either side of a central region 27 of the contact surface 22. Each conductive region 25A is formed in a corresponding one of a pair of outer regions 28. One conductive region 25A is formed in one outer region 28, and the other conductive region 25A is formed in the other outer region 28. No conductive region 25A is formed in the central region 27.

[0052] Like the conductive region 25 according to the first embodiment, each conductive region 25A is a region to which a conductive sheet 26A is attached. The conductive sheet 26A may be made of the same material as the conductive sheet 26 according to the first embodiment. The conductive sheet 26A may have the same layer structure as the conductive sheet 26 according to the first embodiment. The conductive sheet 26A is attached to the surface 23b of the main body 23 and the surface 24a of the protrusion 24. In the second embodiment, a pair of conductive sheets 26A are attached. The shape of the conductive sheet 26A is different from the shape of the conductive sheet 26 according to the first embodiment. The conductive sheet 26A is continuously formed in a ring shape along the extension direction of the belt 20 and has no end in the extension direction of the belt 20. The width (length) of the conductive sheet 26A in the extension direction of the belt 20 is greater than the width of the conductive sheet 26A in the width direction of the belt 20.

[0053] In the second embodiment, the belt 20 also has a contact surface 22 that contacts a plurality of rollers 10, and the contact surface 22 has a diameter of 1×10 4 Ω / sq. or more 1×10 11 The conductive region 25A has a surface resistivity of Ω / sq. or less. This allows the generated charge to be widely dispersed in the conductive region 25A and easily discharged into the air, even if the charge is generated by the rotation of the roller 10. Therefore, the belt drive mechanism according to the second embodiment can also suppress static electricity buildup.

[0054] The contact surface 22 includes a pair of conductive regions 25A. The pair of conductive regions 25A are positioned apart from each other and sandwich a central region 27 of the contact surface 22 in the width direction of the belt 20. This prevents the X-rays irradiated to the object 4 to be inspected from being blocked by the conductive region 25A (conductive sheet 26A). This allows for proper X-ray inspection. [Third embodiment]

[0055] The configuration of a belt driving mechanism according to the third embodiment will be described with reference to Fig. 6. The belt driving mechanism according to the third embodiment may be used in place of the belt driving mechanism 1 in the X-ray inspection apparatus 100 according to the first embodiment. The belt driving mechanism according to the third embodiment differs from the belt driving mechanism 1 according to the first embodiment in the shape of the conductive regions formed on the belt 20. As shown in Fig. 6, the contact surface 22 of the belt 20 according to the third embodiment includes a plurality of conductive regions 25B. The conductive regions 25B have a density of 1 x 10 4 Ω / sq. or more 1×10 11 The surface resistivity of the conductive region 25B is measured by the same method as that for the surface resistivity of the conductive region 25. The conductive region 25B has a surface resistivity of Ω / sq. or less.

[0056] Each conductive region 25B is formed from one end to the other end of the contact surface 22 in the width direction of the belt 20. The conductive regions 25B are formed continuously in the width direction of the belt 20. The conductive regions 25B are formed so as to extend from one outer region 28 through the central region 27 to the other outer region 28. The multiple conductive regions 25B are located apart from each other in the extension direction of the belt 20. Between adjacent conductive regions 25B, there is a region where no conductive region 25 is formed.

[0057] Like the conductive region 25 according to the first embodiment, each conductive region 25B is a region to which a conductive sheet 26B is attached. The conductive sheet 26B may be made of the same material as the conductive sheet 26 according to the first embodiment. The conductive sheet 26B may have the same layer structure as the conductive sheet 26 according to the first embodiment. The conductive sheet 26B is attached to the surface 23b of the main body 23 and the surface 24a of the protrusion 24. In the third embodiment, multiple conductive sheets 26B are attached. Each conductive sheet 26B is formed in a rectangular shape in a plan view. The width of the conductive sheet 26B in the extension direction of the belt 20 is smaller than the width of the conductive sheet 26B in the width direction of the belt 20. Each conductive sheet 26B is formed from one end to the other end of the contact surface 22 in the width direction of the belt 20. The conductive sheet 26B is formed continuously in the width direction of the belt 20. The conductive sheet 26B is formed so as to extend from one outer region 28 through the central region 27 to the other outer region 28.

[0058] In the third embodiment, the belt 20 also has a contact surface 22 that contacts a plurality of rollers 10, and the contact surface 22 has a diameter of 1×10 4 Ω / sq. or more 1×10 11 The belt driving mechanism according to the third embodiment also includes a conductive region 25B having a surface resistivity of Ω / sq. or less. This allows the generated charge to be widely dispersed in the conductive region 25B and easily discharged into the air, even if the charge is generated by the rotation of the roller 10. Therefore, the belt driving mechanism according to the third embodiment also suppresses static electricity buildup.

[0059] The contact surface 22 includes a plurality of conductive regions 25B. The plurality of conductive regions 25B are positioned apart from one another in the extension direction of the belt 20, which intersects with the width direction of the belt 20. This makes it easier to form the conductive regions 25B than when conductive regions are formed over the entire contact surface 22.

[0060] The conductive region 25B is formed across the width of the contact surface 22 from one end to the other end of the contact surface 22 of the belt 20. This ensures a large area for the conductive region 25B on the contact surface 22, and more reliably suppresses static electricity buildup. [Variations]

[0061] The present disclosure is not limited to the above-described embodiments. The conductive region 25 may be a region to which a powdery conductive material such as metal powder is attached. The powdery conductive material may be, for example, metal powder remaining on the surfaces 23b and 24a of the main body 23 and the surfaces 24a of the protrusions 24 when the metal sheet is peeled off after being attached to the surfaces 23b and 24a. The powdery conductive material may be contained in an adhesive layer of the metal sheet. The material of the powdery conductive material may be, for example, metal such as aluminum, gold, silver, copper, nickel, lead, or zinc, or graphite, carbon nanotubes (CNT), carbon, or the like. The conductive region 25 to which the powdery conductive material is attached may have a density of 1×10 4 Ω / sq. or more 1×10 11 The surface resistivity is 1×10 Ω / sq. or less. 4 Ω / sq. or more 1×10 11 The resistivity may be adjusted to be Ω / sq. or less. When the conductive region 25 is a region to which a powdery conductive material is attached, the conductive region 25 can be formed with a simple configuration. Furthermore, since the powdery conductive material that constitutes the conductive region 25 is less likely to peel off, static electricity can be more reliably suppressed. Like the conductive region 25, the conductive region 25A of the second embodiment and the conductive region 25B of the third embodiment may be a region to which metal powder is attached.

[0062] The conductive region 25 may be a region to which a liquid or gel-like conductive substance, such as conductive paste or conductive grease, is applied. In this case, the conductive region 25 may be formed, for example, by applying a conductive paste or the like to the surface 23b of the main body 23 and the surface 24a of the protrusion 24. The conductive paste is a paste-like substance having conductivity. The conductive grease is a conductive grease (a semi-solid or semi-fluid substance). The conductive paste may contain a conductive substance (e.g., conductive powder) and a resin (binder) that holds the conductive substance. The conductive grease is a mixture of a low electrical resistance substance, such as a conductive substance, and an oil or fat, such as grease. The conductive substance may be, for example, a metal material, such as aluminum, gold, silver, copper, nickel, lead, or zinc, as well as powders of graphite, carbon nanotubes (CNT), carbon, or the like. The conductive region 25 to which a liquid or gel-like conductive substance is applied has a density of 1×10 4 Ω / sq. or more 1×10 11 The surface resistivity is Ω / sq. or less. The amount of conductive material (conductive powder) contained in the liquid or gel conductive material is such that the surface resistivity is 1×10 4 Ω / sq. or more 1×10 11 The resistivity may be adjusted to be Ω / sq. or less. When the conductive region 25 is a region to which a liquid or gel-like conductive material is applied, the conductive region 25 can be formed with a simple configuration. Furthermore, since the liquid or gel-like conductive material that constitutes the conductive region 25 is difficult to peel off, static electricity can be more reliably suppressed. Like the conductive region 25, the conductive region 25A of the second embodiment and the conductive region 25B of the third embodiment may be a region to which a conductive paste is applied.

[0063] The conductive region 25 may be a region to which an antistatic agent is attached. In this case, the conductive region 25 may be formed, for example, by attaching an antistatic agent to the surface 23b of the main body 23 and the surface 24a of the protrusion 24. When the antistatic agent is a liquid, the antistatic agent may be attached by spraying. The antistatic agent may be, for example, a surfactant, an inorganic filler, a conductive polymer, an ionic liquid, or the like. The conductive region 25 to which the antistatic agent is attached has a density of 1×104 Ω / sq. or more 1×10 11 The surface resistivity is 1×10 Ω / sq. or less. The components and amount of antistatic agent applied are 4 Ω / sq. or more 1×10 11 It may be adjusted to be Ω / sq. or less.

[0064] The surface of an object to which a surfactant is attached absorbs moisture contained in the surrounding air. In other words, the surfactant creates a condition in which electricity can easily flow on the surface of the object to which it is attached, thereby suppressing static electricity buildup. When the conductive region 25 is a region to which an antistatic agent (such as a surfactant) is attached, the conductive region 25 can be formed with a simple configuration. Furthermore, since the antistatic agent constituting the conductive region 25 is less likely to peel off, static electricity buildup can be more reliably suppressed. Like the conductive region 25, the conductive region 25A of the second embodiment and the conductive region 25B of the third embodiment may be a region to which an antistatic agent (such as a surfactant) is attached. In the case of a conductive polymer-type antistatic agent, the antistatic function is exhibited by metal ions (ion conductors) added to the material facilitating the flow of electricity. In the case of an inorganic filler-type antistatic agent, the inorganic filler added to the material facilitating the flow of electricity, thereby exhibiting the antistatic function. Furthermore, in the case of an ionic liquid-type antistatic agent, the ionic liquid itself is liquid and has fluidity, and the unevenness of the charge generated on the surface of the object is reduced by the uneven concentration of the ionic liquid, etc. The ionic liquid-type antistatic agent has the advantage that its antistatic function is less dependent on temperature and humidity.

[0065] The contact surface 11 of the roller 10 may include a conductive area. The conductive area included in the contact surface 11, like the conductive area 25, may be 1×10 4 Ω / sq. or more 1×10 11The conductive region included in the contact surface 11 is a region having a surface resistivity of Ω / sq. or less. Like the conductive region 25, the conductive region included in the contact surface 11 may be a region to which a conductive sheet is attached, a region to which a powdery conductive material such as metal powder is attached, a region to which a liquid or gel-like conductive material such as conductive paste or conductive grease is applied, or a region to which an antistatic agent is attached. The antistatic agent may be, for example, a surfactant, an inorganic filler, a conductive polymer, an ionic liquid, or the like. The conductive sheet, powdery conductive material, liquid or gel-like conductive material, and antistatic agent forming the conductive region included in the contact surface 11 may have the same configuration (type of material, amount and ratio of material, layer structure, etc.) as the conductive sheet, etc. forming the conductive region 25 described above. The contact surface 11 of at least one roller 10 among the plurality of rollers 10 included in the belt driving mechanism 1 may include a conductive region.

[0066] When the contact surface 11 includes a plurality of conductive regions, the plurality of conductive regions may be positioned apart from one another in both the direction along the central axis C of the roller 10 and the circumferential direction of the circle surrounding the central axis C. The conductive regions included in the contact surface 11 may be formed continuously in an annular shape along the circumferential direction of the circle surrounding the central axis C. The conductive regions included in the contact surface 11 may be formed from one end of the contact surface 11 to the other end in the direction along the central axis C. When the contact surface 11 includes a conductive region, the contact surface 22 of the belt 20 may not include a conductive region 25. That is, at least one of the contact surface 22 and the contact surface 11 may have a conductive area of ​​1×10 4 Ω / sq. or more 1×10 11 It is sufficient that the conductive layer includes a conductive region having a surface resistivity of Ω / sq. or less.

[0067] The belt drive mechanism 1 may be applied to an apparatus other than the X-ray inspection apparatus 100. For example, the belt drive mechanism 1 may be a drive mechanism for a virtual slide scanner. The X-ray detection unit 3 may be arranged outside the belt 20. The number of rollers 10 is not limited. The belt drive mechanism 1 may include three or more rollers 10. The shape of the convex portions 24 is not limited. The convex portions 24 may be formed discontinuously in the width direction of the belt 20. The belt 20 may not have the convex portions 24. In this case, the entire conductive region 25 may be arranged on the surface 23b of the main body portion 23.

[0068] The position and shape of the conductive region formed on contact surface 22 or contact surface 11 are not limited. For example, conductive region 25 may be located in central region 27. Conductive region 25A may be formed discontinuously along the extension direction of belt 20. That is, each conductive region 25A may have an end in the extension direction of belt 20. The conductive region may be formed over the entirety of at least one of contact surface 22 and contact surface 11. [Example]

[0069] The present disclosure will be described in more detail below by showing the results of experiments using examples and comparative examples according to the present disclosure. Note that the present disclosure is not limited to these examples. FIG. 7 shows the measurement results of the charging voltage when a belt drive mechanism equipped with a rubber belt was driven. In the measurements for Examples 1 to 3 and Comparative Examples 1 to 3 shown in FIG. 7, the belt was moved by the rotation of rollers, and then the charging voltage on the belt was measured. The belt drive mechanism for each of Examples 1 to 3 and Comparative Examples 1 to 3 includes multiple rollers (pulleys) made of iron and a rubber belt stretched over the multiple rollers. The measurements for Comparative Examples 1 and 2 and Examples 1 and 2 were performed in a common experimental environment. The measurements for Comparative Example 3 and Example 3 were performed in a common experimental environment.

[0070] The belt drive mechanism of Comparative Example 1 does not have antistatic measures. Specifically, the belt of Comparative Example 1 does not include the conductive region (such as a region where a conductive sheet or the like is attached) described in the above embodiment and modified example. Furthermore, in Comparative Example 1, the roller is not grounded as in Comparative Example 2 described below. The measured value of the charged voltage in Comparative Example 1 was "+170 V." In the belt drive mechanism of Comparative Example 2, like Comparative Example 1, the belt does not include a conductive region, but the roller made of iron is grounded as an antistatic measure. However, the measured value of the charged voltage in Comparative Example 2 was "+170 V," confirming that the antistatic measure (grounding the roller) in Comparative Example 2 does not suppress the generation of static electricity.

[0071] In Example 1, an antistatic agent (surfactant) was sprayed onto the entire contact surface of the belt with the roller (the surface corresponding to contact surface 22). The measured value of the charged voltage in Example 1 was "near ±0 V," confirming that the generation of static electricity was significantly suppressed. In Example 2, an antistatic agent (surfactant) was sprayed onto a portion of the contact surface of the belt with the roller. The measured value of the charged voltage in Example 2 was "-20 V," confirming that the generation of static electricity was suppressed. These measurement results confirm that the generation of static electricity is suppressed by applying an antistatic agent to a belt made of rubber.

[0072] The belt drive mechanism of Comparative Example 3, like Comparative Example 1, was not provided with anti-static measures. The measured value of the electrostatic voltage in Comparative Example 3 was "-70 V." In Example 3, aluminum tape was attached discretely (at intervals) over the entire contact surface of the belt with the roller. The measured value of the electrostatic voltage in Example 3 was "near ±0 V," confirming that the generation of static electricity was significantly suppressed. These measurement results confirmed that the generation of static electricity was suppressed by attaching aluminum tape to a belt made of rubber.

[0073] Fig. 8 shows the measurement results of the electrostatic voltage when a belt drive mechanism equipped with a belt made of polyurethane was driven. In the measurements for Examples 4 to 6 and Comparative Examples 4 to 6 shown in Fig. 8, the belt was moved by the rotation of the rollers, and then the electrostatic voltage on the belt was measured. The belt drive mechanism for each of Examples 4 to 6 and Comparative Examples 4 to 6 includes multiple rollers (pulleys) made of iron, and a polyurethane belt stretched over the multiple rollers. The measurements for Comparative Examples 4 and 5 and Examples 4 and 5 were carried out in a common experimental environment. The measurements for Comparative Example 6 and Example 6 were carried out in a common experimental environment.

[0074] The belt drive mechanism of Comparative Example 4 does not have antistatic measures. Specifically, the belt of Comparative Example 4 does not include a conductive region. Furthermore, in Comparative Example 4, the roller is not grounded as in Comparative Example 5, which will be described later. The measured value of the charged voltage in Comparative Example 4 was 1.5 kV. In the belt drive mechanism of Comparative Example 5, the belt does not include a conductive region, as in Comparative Example 4, but the roller made of iron is grounded as an antistatic measure. However, the measured value of the charged voltage in Comparative Example 5 was 1 kV, confirming that the antistatic measure (grounding the roller) in Comparative Example 5 does not suppress the generation of static electricity.

[0075] In Example 4, an antistatic agent (surfactant) was sprayed onto the entire contact surface of the belt with the roller. The measured value of the charging voltage in Example 4 was 400 V, confirming that the generation of static electricity was suppressed. In Example 5, an antistatic agent (surfactant) was sprayed onto a portion of the contact surface of the belt with the roller. The measured value of the charging voltage in Example 5 was 700 V, confirming that the generation of static electricity was suppressed. These measurement results confirm that the generation of static electricity is suppressed by applying an antistatic agent to a belt made of polyurethane.

[0076] The belt drive mechanism of Comparative Example 6, like Comparative Example 4, was not provided with antistatic measures. The measured value of the electrostatic voltage in Comparative Example 6 was "1.5 kV." In Example 6, aluminum tape was attached discretely (at intervals) over the entire contact surface of the belt with the roller. The measured value of the electrostatic voltage in Example 6 was "50 V," confirming that the generation of static electricity was significantly suppressed. These measurement results confirmed that the generation of static electricity was suppressed by attaching aluminum tape to a belt made of polyurethane.

[0077] Figure 9 is a graph showing the relationship between the area of ​​antistatic agent applied and the maximum charging voltage of a belt. In this experiment, the proportion of the area of ​​the belt contacting the roller where the antistatic agent was applied (the conductive area) was varied, and the charging voltage of the belt after the belt drive mechanism was driven was measured. The horizontal axis represents the ratio (unit: %) of the area of ​​the antistatic agent applied (the conductive area) to the total area of ​​the belt contacting the roller. The vertical axis represents the measured maximum charging voltage (unit: V). In this experiment, a rubber belt with a tooth cloth (cloth belt) was used. The belt had 198 teeth (corresponding to the protrusions 24). The maximum charging voltage was measured by increasing the number of teeth applied with the antistatic agent by 20 increments (increasing the proportion of the conductive area on the contact surface by 10%). As shown in Figure 9, the maximum charging voltage decreased as the area of ​​the antistatic agent applied increased. By applying the antistatic agent to 15% or more of the contact surface, the maximum charging voltage could be reduced to approximately 50 V. By applying an antistatic agent to 30% or more of the contact surface, the maximum charging voltage can be further reduced, and the generation of static electricity can be significantly suppressed. [Explanation of symbols]

[0078] 1...belt drive mechanism, 2...X-ray irradiation unit, 3...X-ray detection unit, 4...item, 10...roller, 11...contact surface (second contact surface), 20...belt, 22...contact surface (contact surface, first contact surface), 25, 25A, 25B, 251, 252...conductive area, 26, 26A, 26B...conductive sheet, 27...central area, 100...X-ray inspection device.

Claims

1. A plurality of rollers; a belt wound around the plurality of rollers, the belt has a contact surface that contacts the plurality of rollers, The contact surface is 1×10 ４ Ω / sq. More than 1×10 １１ a conductive region having a surface resistivity of less than or equal to Ω / sq. Belt drive mechanism.

2. The conductive area is an area where a conductive sheet is attached.

2. The belt drive mechanism of claim 1.

3. The conductive sheet is a tape made of aluminum.

3. The belt drive mechanism of claim 2.

4. The conductive region is a region to which a powdery conductive material is attached.

2. The belt drive mechanism of claim 1.

5. The conductive area is an area to which a liquid or gel-like conductive substance is applied.

2. The belt drive mechanism of claim 1.

6. The conductive area is an area to which an antistatic agent is attached.

2. The belt drive mechanism of claim 1.

7. The antistatic agent is a surfactant.

7. The belt drive mechanism of claim 6.

8. the conductive region is formed across the contact surface in the width direction of the belt from one end to the other end.

3. The belt drive mechanism according to claim 1 or 2.

9. The contact surface has a region that is made up of the conductive region and a region that does not include the conductive region.

3. The belt drive mechanism according to claim 1 or 2.

10. the contact surface includes a plurality of conductive regions, each of which is the conductive region; The plurality of conductive regions are spaced apart from one another in an extension direction of the belt that intersects with the width direction of the belt.

3. The belt drive mechanism according to claim 1 or 2.

11. the contact surface includes a pair of conductive regions, each of which is the conductive region; the pair of conductive regions are spaced apart from each other and sandwich a central region of the contact surface in the width direction of the belt; 3. The belt drive mechanism according to claim 1 or 2.

12. the contact surface includes at least one conductive area, each of the conductive areas being a conductive area; the total area of ​​the at least one conductive region is 30% or more of the total area of ​​the contact surface; 3. The belt drive mechanism according to claim 1 or 2.

13. The belt drive mechanism according to claim 1 or 2; an X-ray irradiation unit that irradiates X-rays onto the object being conveyed by the belt; an X-ray detection unit that detects X-rays that have passed through the article, X-ray inspection equipment.

14. the belt is positioned so as to surround the plurality of rollers, The X-ray detection unit is disposed inside the belt.

14. An X-ray inspection apparatus according to claim 13.

15. the contact surface includes a pair of conductive regions, each of which is the conductive region; the pair of conductive regions are spaced apart from each other and sandwich a central region of the contact surface in the width direction of the belt; 14. An X-ray inspection apparatus according to claim 13.

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