Web conveying device and web conveying system

Abstract

To reduce an eccentricity of a conveyor roller shaft.SOLUTION: A web conveying device of the invention includes: a conveyor roller that conveys a web; annular strain sensors provided circumferentially on a surface of the conveyor roller; and an axial angle control unit that controls an axial angle of the conveyor roller based on an output value of the strain sensor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a web transport device and a web transport system. [Background technology]

[0002] Web transport devices that continuously transport a long strip-shaped web by a roll-to-roll method are disclosed, for example, in Patent Documents 1 and 2. The web transport device disclosed in Patent Document 1 has a roll that transports the web and a pressure-sensitive strain gauge sensor that is spirally embedded in the roll surface so as to contact the web, and measures the lateral tension profile of the web. Meanwhile, the web transport device disclosed in Patent Document 2 has a rod bar for forming a coating film on the web and a panel with a strain gauge attached, and the strain gauge detects pressure from the web and adjusts the amount of pressure of the rod bar against the web. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-527361 [Patent Document 2] Japanese Patent Application Publication No. 8-294665 Summary of the Invention [Problem to be solved by the invention]

[0004] In a web transport device, if a transport roller rotates while being axially eccentric, the transport roller may vibrate, which may cause wrinkles or cracks in the web.

[0005] The present invention has been made in view of the above-mentioned points, and has an object to provide a web transport device capable of reducing axial eccentricity of the transport roller. [Means for solving the problem]

[0006] The web transport device according to the present disclosure comprises a transport roller for transporting a web, an annular strain sensor provided circumferentially on the surface of the transport roller, and an axial angle control unit for controlling the axial angle of the transport roller based on the output value of the strain sensor. Effect of the Invention

[0007] According to the disclosed technique, it is possible to reduce the axial eccentricity of the transport roller. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an overview of a web transport device according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating a configuration of a transport roller. [Diagram 3] 13 is a schematic diagram of the conveying roller connected to the roller adjustment mechanism. FIG. [Figure 4] FIG. 2 is a block diagram showing an example of a hardware configuration of a control device. [Diagram 5] FIG. 2 is a block diagram showing an example of a software configuration of the control device. [Figure 6] 11 is a diagram showing an example of a calculation process of a shaft eccentricity identifying unit. FIG. [Figure 7] FIG. 2 is a plan view illustrating a strain gauge. [Figure 8] FIG. 1 is a cross-sectional view (part 1) illustrating a strain gauge. [Figure 9] FIG. 2 is a cross-sectional view (part 2) illustrating a strain gauge. [Figure 10] 13A and 13B are a plan view and a cross-sectional view illustrating an example of a detection element included in a web transport device according to a third embodiment. [Figure 11] 13A to 13C are a perspective view, a plan view, and a cross-sectional view illustrating an example of a detection element included in a web transport device according to a fourth embodiment. [Figure 12] 13A to 13C are a perspective view, a plan view, and a cross-sectional view showing another example of a detection element included in a web transport device according to a fourth embodiment. [Figure 13]13A to 13C are a perspective view, a plan view, and a cross-sectional view showing still another example of a detection element included in a web transport device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same components may be denoted by the same reference numerals. In addition, in the description of each drawing, the description of components that are the same as those already described may be omitted.

[0010] First Embodiment [Web transport device configuration example] 1 is a schematic diagram showing an overview of a web transport device 100 according to a first embodiment. The web transport device 100 is a device that transports a long strip-shaped web 110 by transport rollers 120. The type of web 110 is not particularly limited as long as it can be transported by the web transport device 100. Examples of the web 110 include a synthetic resin film, a metal foil, and paper.

[0011] The position of the transport roller 120 in the web transport or processing line is not particularly limited. For example, in the transport or processing line, the transport roller 120 may be located immediately after the unwinding roller and / or immediately before the winding roller, or may be located between multiple areas where processing is performed. The transport roller 120 may also be an unwinding roller that unwinds the web 110 from a roll, or a winding roller that winds up the web 110. A plurality of web transport devices 100 may be located in the same transport or processing line.

[0012] The web transport device 100 according to this embodiment includes transport rollers 120, strain sensors 120A-120C, a roller adjustment mechanism 160, and a control device 170. Although details will be described later, the web transport device 100 can eliminate or reduce the axial eccentricity of the transport rollers 120 by controlling the shaft angle of the transport rollers 120. In this specification, the term "axial eccentricity" refers to the deviation between the center of the shaft and the center of the path traveled by the rotation of the center of the shaft.

[0013] [Transport roller] Next, the physical configuration of the conveying roller 120 and the roller adjustment mechanism 160 of this embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a schematic diagram showing the configuration of each part of the conveying roller 120. Fig. 3 is a schematic diagram showing the connection part between the conveying roller 120 and the roller adjustment mechanism 160.

[0014] 2, the conveying roller 120 of this embodiment has a cylindrical roller body 121. The web 110 in contact with the outer circumferential surface of the roller body 121 is conveyed while being tensioned by the rotation of the roller body 121. During conveyance, pressure is applied to the surface of the roller body 121 by the web 110, causing the roller body 121 to distort.

[0015] To detect this strain, one or more annular strain sensors are provided in the circumferential direction on the surface of the roller body 121. In this embodiment, three annular strain sensors 120A-120C are provided in the circumferential direction on the roller body 121 as shown in the figure. Each of the annular strain sensors 120A-120C includes one or more strain gauges 1. The strain gauge 1 according to this embodiment uses a resistor that undergoes a resistance change when subjected to strain as a detection element. The strain gauge 1 will be described in detail later.

[0016] The number of strain sensors provided on the roller body 121 is not particularly limited. The arrangement positions of the strain sensors on the roller body 121 are also not particularly limited. For example, three or more strain sensors may be arranged in the axial direction (width direction) of the roller body 121 in the conveying roller 120. In the present embodiment, as an example, one strain sensor 120A to 120C is arranged in the center of the roller body 121 in the axial direction, and one each in the vicinity of both end faces 121a, 121b of the roller body 121. By arranging the multiple strain sensors symmetrically in the axial direction as shown in the figure, the strain state of the entire conveying roller 120 can be detected with high accuracy.

[0017] The number of strain gauges 1 included in each of the strain sensors 120A to 120C is not particularly limited. For example, each of the annular strain sensors 120A to 120C may be composed of a plurality of strain gauges 1 arranged on the surface of the roller body 121 such that the grid direction is aligned in the circumferential direction of the roller body 121. Furthermore, for example, each of the annular strain sensors 120A to 120C may be a single elongated annular strain gauge 1 arranged on the surface of the roller body 121. In this case, the strain gauge 1 is arranged such that the grid direction is aligned along the circumferential direction of the roller body 121.

[0018] In this embodiment, the surface of the thin-film strain gauge 1 on which the sensing portion is not provided is attached to the outer peripheral surface of the roller body 121. As a result, the sensing portion of the strain gauge 1 is curved along the circumferential direction of the surface of the roller body 121. When the strain gauge 1 is attached, the grid direction of the strain gauge 1 is attached to the roller body 121 in the circumferential direction. By attaching the strain gauge 1 to the roller body 121 in the circumferential direction for approximately one revolution in this way, even if the roller body 121 rotates and the contact position of the web 110 with respect to the roller body 121 changes, it is possible to keep one of the sensing portions of the strain gauge 1 included in the same strain sensor in contact with the web 110 at all times. This allows the strain gauge 1 to continuously detect the pressure that the transport roller 120 receives from the web 110. This allows the pressure applied to the transport roller 120 to be detected in real time.

[0019] A specific method of supporting the conveying roller 120 is not particularly limited. For example, in this embodiment, the conveying roller 120 includes a first joint portion 124 that protrudes along the shaft 123 of the conveying roller 120 on an end surface 121a on one side of the roller body 121. The conveying roller 120 also includes a second joint portion 125 that protrudes in the opposite direction to the first joint portion 124 on an end surface 121b on the other side of the roller body 121. The first joint portion 124 includes a ball portion 1241 at its tip. The second joint portion 125 includes a ball portion 1251 at its tip. The first joint portion 124 and the second joint portion 125 of the conveying roller 120 are supported by a roller adjustment mechanism 160. The conveying roller 120 has an axial angle adjusted via the first joint portion 124 and / or the second joint portion 125.

[0020] As shown in FIG. 3, the ball portion 1241 is connected to the ball receiving portion 161 which is the roller adjustment mechanism 160. Although not shown, the ball portion 1251 is also connected to a ball receiving portion (not shown) on the opposite side of the conveying roller 120 from the ball receiving portion 161. In this manner, the shaft of the conveying roller 120 is rotatably supported by the ball receiving portions at both ends. At least one of the roller adjustment mechanisms 160 (ball receiving portions) at both ends is electrically connected to the control device 170 described later. In this embodiment, it is assumed that the ball receiving portion 161 is connected to the control device 170. Note that the arrangement of the control device 170 in FIG. 3 is an example, and the position of the control device 170 is not limited thereto.

[0021] The roller adjustment mechanism 160 is a mechanism that supports the conveying roller 120 and physically adjusts the shaft angle of the conveying roller 120. A part of the configuration of the roller adjustment mechanism 160 may be attached to the side wall 101 in the vicinity of the conveying roller 120. The roller adjustment mechanism 160 includes, for example, ball receiving portions 161 at both ends of the conveying roller 120 and a driving unit 162 that rotates at least one of the ball receiving portions 161. In this embodiment, the driving unit 162 rotates the ball receiving portions 161. An example of the driving unit 162 is an actuator such as a motor. The driving unit 162 is electrically connected to the control device 170 and operates in response to a control signal from the control device 170.

[0022] The control device 170 controls the shaft angle of the conveying roller 120 by sending a control instruction to the driving unit 162. More specifically, the driving unit 162 operates in response to a control signal from the control device 170, thereby rotating the ball receiving unit 161. As a result, the shaft angle of the conveying roller 120 is adjusted.

[0023] The physical and electrical connection method between the transport roller 120 and the roller adjustment mechanism 160 is not limited to the configuration shown in Figures 2 and 3. In this embodiment, the control device 170 is provided near the drive unit 162, but as long as the control device 170 is electrically connected to the drive unit 162, the location of the control device 170 is not important.

[0024] Furthermore, one control device 170 may control multiple drive units 162, or one control device 170 may control one drive unit 162. For example, in addition to the above-mentioned device configuration, a configuration may be adopted in which drive units 162 are provided at both ends of the conveying roller 120 and these drive units 162 are controlled by one control device 170. Alternatively, a configuration may be adopted in which drive units 162 are provided at both ends of the conveying roller 120 and these drive units 162 are controlled by separate control devices 170.

[0025] [Control device] Next, the control device 170 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a block diagram showing an example of a hardware configuration of the control device 170. Fig. 5 is a block diagram showing an example of a software configuration of the control device 170. Note that in order to show inputs to the control device 170 and outputs from the control device 170, configurations other than the control device 170 are also shown in Fig. 4 and Fig. 5.

[0026] As shown in FIG. 4, the control device 170 includes a central processing unit (CPU) 171, a read only memory (ROM) 172, a random access memory (RAM) 173, a hard disk drive (HDD) 174, and input / output interfaces (I / Fs) 175 and 176.

[0027] The input / output I / F 175 is an input / output interface that connects the strain gauges included in each of the strain sensors 120A to 120C to the CPU 171. The electrodes of the strain gauges are connected to the input / output I / F 175. Wiring and electrodes for connecting the strain gauges (or the entire strain sensor) to other members may be housed inside the roller body 121. This prevents the surface of the roller body 121 from becoming uneven due to electrical connections, which may cause wrinkles in the web 110. The input / output I / F 175 may include an analog front end for connecting to these electrodes. The analog front end includes, for example, bridge circuits, amplifiers, analog / digital conversion circuits (A / D conversion circuits), etc., the number of which is equal to the number of strain gauges, and amplifies and digitally converts the analog voltages obtained from the electrodes of each strain gauge, and outputs the amplified and digitally converted voltages to the CPU 171.

[0028] The CPU 171 appropriately reads out programs stored in the ROM 172, the HDD 174, etc., and data required for executing the programs onto the RAM 173. The CPU 171 executes the read out programs to realize various functions of the control device 170 (at least the functions of a shaft eccentricity identifying unit 178 and a shaft angle adjusting unit 179, which will be described later). These functions will be described later. The CPU 171 is connected to the drive unit 162 via an input / output I / F.

[0029] The input / output I / F 176 is an input / output interface that connects the CPU 171 and the drive unit 162. For example, the input / output I / F 176 outputs a control signal output from the CPU 171 to the drive unit 162. The drive unit 162 drives (rotates) in accordance with the control signal output from the CPU 171. Note that when the control device 170 controls a plurality of drive units 162, the CPU 171 may transmit a control signal instructing each of the plurality of drive units 162 to perform a different movement (angle and amount of rotation).

[0030] Next, the functional blocks of the control device 170 will be described with reference to Fig. 5. As shown in Fig. 5, the control device 170 includes a shaft eccentricity identifying unit 178 and a shaft angle control unit 179. The control device 170 obtains resistance values ​​corresponding to the amount of strain as output values ​​from the strain sensors 120A-120C. Here, the output value of each of the strain sensors 120A-120C can be said to indicate the pressure that the transport roller 120 receives from the web 110 at the installation position of each strain sensor.

[0031] The axial eccentricity specifying unit 178 specifies the direction and amount of axial eccentricity of the conveying roller 120 based on the resistance value (i.e., the output value of the strain sensor) acquired by the control device 170. A method for specifying the direction and amount of axial eccentricity by the axial eccentricity specifying unit 178 will be described in detail later. The axial eccentricity specifying unit 178 further calculates an operation of the driving unit 162 required to reduce the direction and amount of axial eccentricity of the conveying roller 120.

[0032] The shaft angle control unit 179 creates a control instruction for realizing the operation of the drive unit 162 calculated by the shaft eccentricity identification unit 178. The shaft angle control unit 179 outputs the created control instruction as an electric signal (i.e., a control signal) to the drive unit 162 via the input / output I / F. That is, the shaft angle control unit 179 controls the shaft angle of the conveying roller 120 via the drive unit 162.

[0033] The driving unit 162 rotates according to the control instruction indicated by the control signal. This causes the ball receiving portion 161 to rotate and / or the angle of the ball receiving portion 161 to change. Therefore, the shaft angle of the conveying roller 120 connected to the ball receiving portion 161 is adjusted so that the shaft eccentricity of the conveying roller 120 becomes smaller. Note that the maximum amount and maximum angle by which the ball receiving portion 161 can rotate and / or change its angle may be determined appropriately. In addition, the position of the ball receiving portion 161 itself may be moved up and down and / or left and right by being driven by the driving unit 162. In this way, by adjusting the position of the ball receiving portion 161 as well, the shaft angle of the conveying roller 120 can be controlled more accurately.

[0034] [How to identify shaft eccentricity] Next, an example of the calculation process by the shaft eccentricity identifying unit 178 will be described. The shaft eccentricity identifying unit 178 may identify the direction and amount of axial eccentricity of the conveying roller 120 based on, for example, the arrangement position of the strain sensor, the output value, and a predetermined reference value. Here, the "reference value" is the output value of the strain sensor when the conveying roller 120 is in a normal state (i.e., when no axial eccentricity occurs in the conveying roller 120). Note that, when there are multiple strain sensors as in this embodiment, the reference value may be set for each strain sensor. The reference value may be stored in advance in the ROM 172 or HDD 174 of the control device 170.

[0035] The axial eccentricity identifying unit 178 compares the output values ​​of the strain sensors 120A to 120C with their respective reference values. When the output value of a certain strain sensor is greater than the reference value of the sensor, it can be said that the pressure applied to the conveying roller 120 at the arrangement position of the strain sensor is excessive compared to the normal state. On the other hand, when the output value of a certain strain sensor is smaller than the reference value of the sensor, it can be said that the pressure applied to the conveying roller 120 at the arrangement position of the strain sensor is excessive compared to the normal state. In this way, when the pressure applied to the conveying roller 120 is excessive or excessively small, it can be said that axial eccentricity has occurred. In this way, the axial eccentricity identifying unit 178 can identify in which direction and to what extent the entire conveying roller 120 is tilted (i.e., the direction and amount of axial eccentricity) based on the arrangement position, output value, and reference value of each strain sensor. Then, the axial eccentricity identifying unit 178 calculates the operation of the driving unit 162 so that the output value of each strain sensor matches or approaches the reference value.

[0036] Furthermore, in the case where a plurality of strain sensors are provided on the conveying roller 120 as in this embodiment, the direction and amount of eccentricity of the shaft of the conveying roller 120 can be more accurately identified by comparing the differences for each strain sensor. FIG. 6 is a diagram showing an example of the calculation process of the shaft eccentricity identification unit 178. As shown in FIG. 6(a), it is assumed that the reference values ​​of the strain sensors 120A to 120C of the conveying roller 120 are set as X(Ω) for the strain sensor 120A, Y(Ω) for the strain sensor 120B, and Z(Ω) for the strain sensor 120C. It is also assumed that the output values ​​(and differences) shown in FIG. 6(b) are obtained for the strain sensors 120A to 120C. For example, it is assumed that the output values ​​of X+20(Ω) are obtained from the strain sensor 120A, Y+10(Ω) from the strain sensor 120B, and Z-15(Ω) are obtained from the strain sensor 120C. In this case, a comparison of the output values ​​of each strain sensor with the reference value reveals that the pressure applied to the conveying roller 120 at the position of strain sensor 120A is excessive, and that the pressure applied to the conveying roller 120 at the position of strain sensor 120C is too small.

[0037] In this way, when the shaft eccentricity specifying unit 178 specifies the direction and magnitude of the shaft eccentricity, it calculates the operation of the drive unit 162 to reduce the angle and magnitude. In the example of FIG. 6, the shaft eccentricity specifying unit 178 calculates the operation of the drive unit 162 to move the side where the strain sensor 120A is arranged away from the web 110. For example, when the conveying roller 120 in each diagram of FIG. 6 is in contact with the web 110 in the upward direction in the diagram, the shaft eccentricity specifying unit 178 calculates the operation of the drive unit 162 to lower the strain sensor 120A side. Then, the shaft angle control unit 179 receives the calculation result of the shaft eccentricity specifying unit 178 and creates a control instruction to realize it. The drive unit 162 operates according to the control instruction to change the rotation and / or angle of the ball receiving unit 161. As a result, the shaft angle of the conveying roller 120 is adjusted in the direction of the arrow in FIG. 6(c). As a result, the axial eccentricity is reduced, and the output values ​​of the strain sensors 120A-120C approach the reference value, as shown in Fig. 6(d). In this manner, the web transport device 100 repeats the process of identifying the direction and magnitude of the axial eccentricity and controlling the drive unit 162 (and thus the shaft angle) in accordance with the identification result, thereby bringing the transport roller 120 closer to the normal state.

[0038] As described above, according to this embodiment, the axial eccentricity of the conveying roller 120 can be reduced by controlling the axial angle of the conveying roller 120 based on the output value of the strain sensor provided on the conveying roller 120. This makes it possible to prevent wrinkles and cracks from occurring in the conveyed web 110.

[0039] [Strain gauge] Next, the strain gauge 1 included in the strain sensors 120A to 120C of this embodiment will be described in detail with reference to FIGS. 7 to 9. FIG. 7 is a plan view illustrating the strain gauge 1 of this embodiment. FIG. 8 is a cross-sectional view (part 1) illustrating the strain gauge 1 according to this embodiment, showing a cross section along the line AA in FIG. 7. FIG. 9 is a cross-sectional view (part 2) illustrating the strain gauge 1 including the functional layer 20, showing a cross section along the line AA in FIG. 7. Note that the shapes of the parts of the strain gauge 1 shown in FIGS. 7 to 9 are merely examples, and the appearance of the strain gauge 1 according to this embodiment is not limited to this. For example, when each of the strain sensors 120A to 120C is made of one strain gauge, the grid part of the strain gauge 1 may be large enough to make approximately one revolution around the roller body of the conveying roller 120. Furthermore, each of the strain sensors 120A to 120C may be made up of a plurality of strain gauges 1 arranged on the surface of the transport roller 120 in the circumferential direction.

[0040] 7 to 9, the strain gauge 1 has a substrate 10, a resistor 30, wiring 40, electrodes 50, and a cover layer 60. For convenience, only the outer edge of the cover layer 60 is shown by a dashed line. The cover layer 60 is not an essential component and may be provided as necessary.

[0041] In this embodiment, for convenience, the side of the strain gauge 1 on which the resistor 30 of the substrate 10 is provided is referred to as the "upper side", and the side on which the resistor 30 is not provided is referred to as the "lower side". The surface located on the upper side of each part is referred to as the "upper surface", and the surface located on the lower side of each part is referred to as the "lower surface". However, the strain gauge 1 can also be used upside down. The strain gauge 1 can also be arranged at any angle. The planar view refers to viewing the object in the normal direction from the upper side to the lower side of the upper surface 10a of the substrate 10. The planar shape refers to the shape of the object when the object is viewed in the normal direction.

[0042] The substrate 10 is a member that serves as a base layer for forming the resistor 30 and the like. The substrate 10 has flexibility. The thickness of the substrate 10 is not particularly limited and may be appropriately determined depending on the intended use of the strain gauge 1 and the like. For example, the thickness of the substrate 10 may be about 5 μm to 500 μm. In this embodiment, the lower surface side of the strain gauge 1 is joined to the surface of the roller body 121 of the conveying roller 120 using an adhesive or the like. From the viewpoint of the transferability of strain from the conveying roller 120 to the sensing part and the dimensional stability against environmental changes, the thickness of the substrate 10 is preferably within the range of 5 μm to 200 μm. From the viewpoint of insulation, the thickness of the substrate 10 is preferably 10 μm or more.

[0043] The substrate 10 can be formed from an insulating resin film such as PI (polyimide) resin, epoxy resin, PEEK (polyether ether ketone) resin, PEN (polyethylene naphthalate) resin, PET (polyethylene terephthalate) resin, PPS (polyphenylene sulfide) resin, LCP (liquid crystal polymer) resin, polyolefin resin, etc. The film refers to a flexible member having a thickness of about 500 μm or less.

[0044] When the substrate 10 is formed from an insulating resin film, the insulating resin film may contain a filler, impurities, etc. For example, the substrate 10 may be formed from an insulating resin film containing a filler such as silica or alumina.

[0045] Examples of materials other than resin for the substrate 10 include crystalline materials such as SiO2, ZrO2 (including YSZ), Si, Si2N3, Al2O3 (including sapphire), ZnO, and perovskite ceramics (CaTiO3, BaTiO3). In addition to the above-mentioned crystalline materials, amorphous glass or the like may be used as the material for the substrate 10. Metals such as aluminum, aluminum alloys (duralumin), and titanium may also be used as the material for the substrate 10. When a metal is used, an insulating film is provided on the metallic substrate 10.

[0046] The resistor 30 is a thin film formed in a predetermined pattern on the upper side of the substrate 10. In the strain gauge 1, the resistor 30 is a sensing part that receives strain and produces a resistance change. In other words, the resistor 30 can be said to be the detection element of the strain gauge 1. The resistor 30 may be formed directly on the upper surface 10a of the substrate 10, or may be formed on the upper surface 10a of the substrate 10 via another layer.

[0047] The resistor 30 has a structure in which a plurality of elongated portions 31 are arranged at predetermined intervals with their longitudinal directions in the same direction (the direction of line AA in FIG. 7), and the ends of adjacent elongated portions 31 are alternately connected to form a zigzag fold as a whole. That is, the resistor 30 includes a plurality of elongated portions 31 arranged in parallel, and a fold-back portion 32 that connects the ends of adjacent elongated portions 31. The longitudinal direction of the plurality of elongated portions 31 is the grid direction, and the direction perpendicular to the grid direction is the grid width direction (the direction perpendicular to line AA in FIG. 7).

[0048] One end in the longitudinal direction of the two elongated portions 31 located at the outermost sides in the grid width direction is bent in the grid width direction to form respective ends 30e1 and 30e2 in the grid width direction of the resistor 30. Each of the ends 30e1 and 30e2 in the grid width direction of the resistor 30 is electrically connected to the electrode 50 via the wiring 40. In other words, the wiring 40 electrically connects each of the ends 30e1 and 30e2 in the grid width direction of the resistor 30 to each of the electrodes 50.

[0049] The resistor 30 can be formed from, for example, a material containing Cr (chromium), a material containing Ni (nickel), or a material containing both Cr and Ni. That is, the resistor 30 can be formed from a material containing at least one of Cr and Ni. An example of a material containing Cr is a Cr mixed phase film. An example of a material containing Ni is Cu-Ni (copper nickel). An example of a material containing both Cr and Ni is Ni-Cr (nickel chromium).

[0050] Here, the Cr mixed phase film is a film in which Cr, CrN, Cr2N, etc. are mixed. The Cr mixed phase film may contain inevitable impurities such as chromium oxide.

[0051] For example, when the resistor 30 is a Cr mixed-phase film, the stability of the gauge characteristics can be improved by making α-Cr (alpha chromium) which is a stable crystal phase the main component. For example, when the resistor 30 is a Cr mixed-phase film, the resistor 30 can make α-Cr the main component, so that the gauge factor of the strain gauge 1 is 10 or more, and the gauge factor temperature coefficient TCS and the resistance temperature coefficient TCR can be in the range of -1000 ppm / °C to +1000 ppm / °C. Here, the "main component" means a component which occupies 50% by weight or more of the total material constituting the resistor 30. From the viewpoint of improving the gauge characteristics, the resistor 30 preferably contains 80% by weight or more of α-Cr. More specifically, from the same viewpoint, the resistor 30 more preferably contains 90% by weight or more of α-Cr. Note that α-Cr is Cr with a bcc structure (body-centered cubic lattice structure).

[0052] When the resistor 30 is a Cr mixed-phase film, the Cr mixed-phase film preferably contains 20% by weight or less of CrN and Cr2N. By containing 20% ​​by weight or less of CrN and Cr2N in the Cr mixed-phase film, a decrease in the gauge factor can be suppressed.

[0053] In addition, the ratio of CrN and Cr2N in the Cr mixed phase film is preferably such that the ratio of Cr2N is 80% by weight or more and less than 90% by weight with respect to the total weight of CrN and Cr2N. More specifically, the ratio is more preferably such that the ratio of Cr2N is 90% by weight or more and less than 95% by weight with respect to the total weight of CrN and Cr2N. Cr2N has semiconductor properties. Therefore, by setting the ratio of Cr2N to 90% by weight or more and less than 95% by weight, the decrease in TCR (negative TCR) becomes more significant. Furthermore, by setting the ratio of Cr2N to 90% by weight or more and less than 95% by weight, the resistor 30 is less likely to become ceramic, and the resistor 30 is less likely to be brittle fractured.

[0054] On the other hand, CrN has the advantage of being chemically stable. By including more CrN in the Cr mixed-phase film, the possibility of unstable N being generated can be reduced, resulting in a stable strain gauge. Here, "unstable N" refers to trace amounts of N2 or atomic N that may be present in the Cr mixed-phase film. This unstable N may escape to the outside of the film depending on the external environment (e.g., high-temperature environment). When unstable N escapes to the outside of the film, the film stress of the Cr mixed-phase film may change.

[0055] The thickness of the resistor 30 is not particularly limited and may be appropriately determined depending on the intended use of the strain gauge 1. For example, the thickness of the resistor 30 may be about 0.05 μm to 2 μm. In particular, when the thickness of the resistor 30 is 0.1 μm or more, the crystallinity of the crystals constituting the resistor 30 (for example, the crystallinity of α-Cr) is improved. Furthermore, when the thickness of the resistor 30 is 1 μm or less, (i) film cracks and (ii) warping of the film from the substrate 10 caused by the internal stress of the film constituting the resistor 30 are reduced. The width of the elongated portion 31 may be appropriately determined. For example, when the width of the elongated portion 31 is optimized for the required specifications such as the resistance value and the lateral sensitivity while taking into account the breakage countermeasures, the width of the elongated portion 31 may be about 10 μm to 100 μm.

[0056] In the strain gauge 1, when a Cr mixed-phase film is used as the material of the resistor 30, high sensitivity and miniaturization can be achieved. For example, while the output of a conventional strain gauge was about 0.04 mV / 2 V, an output of 0.3 mV / 2 V or more can be obtained when a Cr mixed-phase film is used as the material of the resistor 30. In addition, while the size (gauge length x gauge width) of a conventional strain gauge was about 3 mm x 3 mm, the size (gauge length x gauge width) of the strain gauge when a Cr mixed-phase film is used as the material of the resistor 30 can be miniaturized to about 0.3 mm x 0.3 mm.

[0057] The wiring 40 is provided on the substrate 10. One end of the wiring 40 is electrically connected to both ends of the resistor 30, and the other end is electrically connected to the electrodes 50. The wiring 40 is not limited to being linear, and may have any pattern. Furthermore, the wiring 40 may have any width and any length.

[0058] The electrodes 50 are provided on the substrate 10. The electrodes 50 are electrically connected to the resistor 30 via the wiring 40. The electrodes 50 may be formed, for example, in a substantially rectangular shape wider than the wiring 40 in a plan view. The electrodes 50 are a pair of electrodes for outputting a change in the resistance value of the resistor 30 caused by strain to the outside. For example, a lead wire for external connection is joined to the electrodes 50.

[0059] The cover layer 60 is formed on the upper surface 10a of the base material 10, covers the resistor 30 and the wiring 40, and exposes the electrodes 50. A part of the wiring 40 may be exposed from the cover layer 60. The cover layer 60 may be provided so as to cover the entire portion except for the electrodes 50.

[0060] Examples of materials for the cover layer 60 include insulating resins such as PI resin, epoxy resin, PEEK resin, PEN resin, PET resin, PPS resin, and composite resins (e.g., silicone resin, polyolefin resin). The cover layer 60 may contain a filler or a pigment. The thickness of the cover layer 60 is not particularly limited and can be appropriately selected depending on the purpose. For example, the thickness of the cover layer 60 can be about 2 μm to 30 μm. By providing the cover layer 60, it is possible to suppress mechanical damage and the like to the resistor 30 (and the wiring 40). Furthermore, by providing the cover layer 60, it is possible to protect the resistor 30 (and the wiring 40) from moisture and the like.

[0061] In order to stabilize the gauge characteristics, the strain gauge 1 may also include a functional layer 20 as a base layer formed on the upper surface 10a of the substrate 10 by, for example, conventional sputtering to a predetermined thickness.

[0062] In the present application, the functional layer 20 refers to a layer having a function of promoting crystal growth of at least the upper layer, the resistor 30. The functional layer 20 preferably further has a function of preventing oxidation of the resistor 30 due to oxygen or moisture contained in the substrate 10, and / or a function of improving adhesion between the substrate 10 and the resistor 30. The functional layer 20 may further have other functions.

[0063] The insulating resin film constituting the substrate 10 may contain oxygen and moisture, and Cr may form a self-oxidized film. Therefore, when the metal layer A contains Cr, it is effective to form a functional layer having a function of preventing the oxidation of the metal layer A.

[0064] The material of the functional layer 20 is not particularly limited as long as it has the function of promoting the crystal growth of at least the upper layer, the resistor 30, and can be appropriately selected depending on the purpose. For example, Cr (chromium), Ti (titanium), V (vanadium), Nb (niobium), Ta (tantalum), Ni (nickel), Y (yttrium), Zr (zirconium), Hf (hafnium), Si (silicon), C (carbon), Zn (zinc), Cu (copper), Bi (bismuth), Examples of the metal include one or more metals selected from the group consisting of Fe (iron), Mo (molybdenum), W (tungsten), Ru (ruthenium), Rh (rhodium), Re (rhenium), Os (osmium), Ir (iridium), Pt (platinum), Pd (palladium), Ag (silver), Au (gold), Co (cobalt), Mn (manganese), and Al (aluminum), an alloy of any of the metals in this group, or a compound of any of the metals in this group.

[0065] The functional layer 20 can be formed in a vacuum by, for example, conventional sputtering in which a raw material capable of forming the functional layer 20 is used as a target and Ar (argon) gas is introduced into a chamber. By using conventional sputtering, the functional layer 20 is formed while etching the upper surface 10a of the substrate 10 with Ar, so that the amount of the functional layer 20 formed can be minimized to obtain an effect of improving adhesion.

[0066] However, this is just one example of a method for forming the functional layer 20, and the functional layer 20 may be formed by other methods. For example, a method may be used in which the upper surface 10a of the substrate 10 is activated by a plasma treatment using Ar or the like before forming the functional layer 20, thereby improving adhesion, and then the functional layer 20 is vacuum-formed by magnetron sputtering.

[0067] When a functional layer 20 is provided on the upper surface 10a of the substrate 10 as an underlayer for the resistor 30, the wiring 40, and the electrodes 50, the strain gauge 1 has a cross-sectional shape as shown in Fig. 9. When the functional layer 20 is provided, the planar shape of the strain gauge 1 becomes similar to, for example, the resistor 30, the wiring 40, and the electrodes 50 in Fig. 7. However, as described above, the functional layer 20 may be formed solidly on a part or all of the upper surface 10a of the substrate 10.

[0068] <Second embodiment> In the first embodiment, an example has been described in which one conveying roller 120 is controlled by one control device 170. However, the present invention may be configured in such a way that a plurality of conveying rollers 120 are controlled by one control device 170. A second embodiment of the present invention will be described below. Note that the same members as those in the first embodiment are given the same member numbers, and the description thereof will not be repeated.

[0069] A web transport system 100a according to this embodiment includes a plurality of transport rollers 120 that transport a web 110, a roller adjustment mechanism 160 provided on each transport roller 120, and a control device 200 that controls the shaft angle of each transport roller 120 via the roller adjustment mechanism 160. As in the first embodiment, each transport roller 120 is provided with one or more annular strain sensors (e.g., strain sensors similar to strain sensors 120A to 120C) in the circumferential direction, and each strain sensor includes one or more strain gauges 1.

[0070] The control device 200 is connected to the strain sensors of the conveying rollers 120 and the drive unit 162 of the roller adjustment mechanism 160 by wire or wirelessly. Although not particularly limited, examples of the control device 200 include information processing devices such as personal computers and servers. The control device 200 has a software configuration similar to that of the control device 170 in the first embodiment. That is, the control device 200 includes at least an axial eccentricity identifying unit 178 and an axial angle control unit 179. The hardware configuration of the control device 200 may be the same as or different from that of the control device 170.

[0071] The control device 200 acquires an output value from each of the strain gauges 1 provided on each conveying roller 120. At this time, the control device 200 acquires the value by distinguishing which conveying roller and which strain sensor each output value is the output value of. The control device 200 controls the shaft angle of the conveying roller 120 in the same manner as the control device 170 according to the first embodiment. At this time, the control device 200 adjusts the shaft angles of the multiple conveying rollers 120 individually. This allows the web conveying system 100a to control the multiple conveying rollers 120 so that the axial eccentricity is reduced. Therefore, for example, the multiple conveying rollers 120 on the conveying line of the web 110 can be collectively controlled so that axial eccentricity is minimized.

[0072] Thus, in the first and second embodiments, an example in which a resistor is used as a detection element of a strain gauge has been described. That is, in the first and second embodiments, a case in which the strain gauge 1 is a so-called "resistor strain gauge" has been described. However, the strain gauge according to the present disclosure is not limited to a resistor strain gauge. For example, the strain gauge according to the present disclosure may be a strain gauge that detects a magnetic change associated with a strain occurring in the conveying roller 120 (i.e., a deformation caused by pressure being applied to the conveying roller 120). The strain gauge that detects the magnetic change may be mounted on the strain sensor described in the first or second embodiment.

[0073] Specifically, the strain gauge according to the present disclosure may be a strain gauge including a detection element utilizing the Villari phenomenon (described later). Also, the strain gauge according to the present disclosure may be a strain gauge including a detection element having a magnetic tunnel junction (described later) structure. In the following, in the third embodiment, a strain gauge including a detection element utilizing the Villari phenomenon will be described. In the fourth embodiment, a strain gauge including a detection element having a magnetic tunnel junction structure will be described.

[0074] Note that the "strain sensor" described in each of the following embodiments and modifications is similar to the annular strain sensor described in the first and second embodiments (for example, a strain sensor similar to strain sensors 120A to 120C).

[0075] <Third embodiment> FIG. 10 is a diagram showing an example of a detection element 300 included in a strain gauge according to the third embodiment. In the third and fourth embodiments, the side of each member on which the roller body 121 is present is referred to as the "lower side", and the side opposite the lower side is referred to as the "upper side". FIG. 10(a) is a plan view of the detection element 300 of the strain gauge seen from the top to the bottom. Meanwhile, FIG. 10(b) shows a cross-sectional view of the detection element 300 shown in FIG. 10(a) in the α-α' plane. Note that the wiring of the detection element 300 is not shown in any of the diagrams in FIG. 10. However, the detection element 300 may also have wiring connecting the drive coil 320 and a power source, which will be described later, and wiring for transmitting the current detected by the sensing coil 380.

[0076] As shown in FIG. 10(a), the detection element 300 includes a driving coil 320, a sensing coil 380, and a base layer 310. The sensing coil 380 is a coil with the base layer 310 as a core material. The driving coil 320 is a coil with the base layer 310 as a core material, and is wound around the outside of the sensing coil. In this way, the driving coil 320 and the sensing coil 380 form a double structure with the driving coil 320 on the outside and the sensing coil 380 on the inside. In this way, by winding the sensing coil 380 on the inside of the driving coil 320, an alternating magnetic field (described later) can be applied uniformly to the entire sensing coil 380. This improves the performance of the detection element 300.

[0077] The driving coil 320 is a coil for generating a magnetic field. When an alternating current is supplied from a power source to the driving coil 320, the driving coil 320 generates an alternating magnetic field around it. The base layer 310 is a substantially flat metal plate (a base metal 370 described later) covered with an insulating layer (an insulating layer 360 described later). The metal plate of the base layer 310 is a magnetic material in the detection element 300. The metal plate of the base layer 310 is magnetized by the alternating magnetic field generated by the driving coil 320. The sensing coil 380 is a coil for detecting the intensity of magnetization of the base metal 370. The materials of the driving coil 320 and the sensing coil 380 are preferably conductive metals such as Cu, Ag, Al, and Au, and alloys of these metals. The number of turns and the size of the cross-sectional area of ​​the driving coil 320 and the sensing coil 380 may be appropriately designed according to the strain detection sensitivity required for the detection element 300.

[0078] The detection element 300 will be described in further detail with reference to the cross-sectional view of Fig. 10(b). Note that the layers 340 to 360 described below are wound around the base metal 370, which is a core material. Therefore, in Fig. 10(b), the layers with the same component number are said to surround and be connected to the base metal 370.

[0079] As described above, the detection element 300 has a structure in which the sensing coil 380 and the driving coil 320 are wound around the base layer 310. The base layer 310 has a structure in which the base metal 370 is covered with the insulating layer 360. The insulating layer 350 is formed so as to surround the insulating layer 360. The insulating layer 350 is a layer including the sensing coil 380, and is a layer in which the gaps in the sensing coil 380 are filled with an insulating material. Furthermore, the insulating layer 340 is formed so as to surround the insulating layer 350. The insulating layer 340 is a layer including the driving coil 320, and is a layer in which the gaps in the driving coil 320 are filled with an insulating material.

[0080] The base metal 370 is preferably made of a soft magnetic material such as an Fe-Si-Al alloy such as Sendust, or an Ni-Fe alloy such as Permalloy, etc. The insulating layers 340, 350, and 360 are preferably made of a dry film or a hardened resist such as photosensitive polyimide that is not affected by the magnetic field.

[0081] As shown in the cross-sectional view of FIG. 10(b), the lower side of the detection element 300 is attached to the substrate 110. The detection element 300 may be a detection element having a flat plate or thin film shape as a whole. When the detection element 300 has a flat plate or thin film shape, it can be attached to the substrate 110 more easily. The substrate 110 is then attached to the roller body 121 of the transport roller 120. The transport roller 120 according to this embodiment may basically have the same configuration and material as the transport roller 120 according to the first and second embodiments. However, it is more preferable that the transport roller 120 is made of a non-magnetic material. The transport roller 120 according to this embodiment can be made of, for example, non-magnetic stainless steel.

[0082] As described above, the detection element 300 according to this embodiment includes the base metal 370, which is a magnetic body. When a current flows through the driving coil 320, a magnetic field is generated, and the base metal 370 is magnetized. When the roller body 121 is deformed in this state, a strain is generated accordingly. The strain is transmitted through the substrate 110, and stress is applied to the base metal 370. When stress is applied to the base metal 370, the magnetic permeability of the base metal 370 changes in response to the stress, and the strength of magnetization changes. In this way, the phenomenon in which the magnetic permeability and strength of magnetization of a magnetic body change due to the application of stress to a magnetic body is called the "Villari phenomenon". According to the configuration of the detection element 300, an AC voltage corresponding to the strength of magnetization of the base metal 370 is induced in the sensing coil 380, which is a pickup coil. Therefore, based on the principle of the Villari phenomenon, the stress applied to the base metal 370 (i.e., the degree of strain of the substrate 110) can be calculated from the value of this AC voltage. In the example shown in FIG. 10(a), the grid direction of the detection element 300 is the α-α' direction in the figure.

[0083] By using this principle, the detection element 300 can detect the strain applied to the base material 110 attached to the roller body 121. That is, the detection element 300 functions as a detection element of a strain gauge.

[0084] In the web transport device 100 and web transport system 100a according to this embodiment, pressure is applied to the transport roller 120 due to the tension of the web 110 when the web 110 is transported. This pressure distorts the roller body 121 of the transport roller 120. The transport roller 120 is equipped with a strain sensor equipped with a strain gauge, and the detection element 300 of the strain gauge can detect the magnetic change caused by the distortion of the roller body 121 based on the principle of the Villari phenomenon described above.

[0085] Moreover, the strain gauge including the detection element 300 according to this embodiment can be arranged in any of the arrangement positions shown in the first and second embodiments. Therefore, the detection element 300 utilizing the Villari phenomenon can be used to detect the strain of the roller body 121 in the same manner as when a resistor strain gauge is used. Therefore, the strain gauge according to this embodiment has the same effects as the strain gauge 1 according to the first and second embodiments.

[0086] <Fourth embodiment> FIG. 11 is a diagram showing an example of a detection element included in a strain gauge according to the fourth embodiment. FIG. 12 is a diagram showing another example of a detection element according to the fourth embodiment. FIG. 13 is a diagram showing yet another example of a detection element according to the third embodiment. (a) of FIG. 11 to 13 is a perspective view of the detection elements 500, 600, and 700, respectively. (b) of FIG. 11 to 13 is a plan view of the detection elements 500, 600, and 700 when looking down from above. (c) of FIG. 11 to 13 is a cross-sectional view of the detection elements 500, 600, and 700 on a plane parallel to the zy plane. Note that the attachment surface of the detection elements 500, 600, and 700 to the base material 110 is a plane parallel to the xy plane. Note that the wiring of the detection elements is not shown in any of FIG. 11 to 13. However, these detection elements 500, 600, and 700 may have wiring that connects the upstream electrode 510 to a power source, and wiring that connects the downstream electrode 520 to a power source, which will be described later.

[0087] 11(a), the detection elements 500, 600, and 700 include an upstream electrode 510, a downstream electrode 520, a magnetic film 530, and an insulating film 540. The insulating film 540 is sandwiched between the magnetic films 530 as shown in the figure. A magnetic tunnel junction is formed by the magnetic film 530 and the insulating film 540. In other words, the detection element 500 has a structure in which an electrode is connected to a magnetic tunnel junction structure.

[0088] A flexible substrate made of a plastic film or the like may be provided further below upstream electrode 510 and / or downstream electrode 520. The substrate may also serve as base material 110.

[0089] The magnetic film 530 is a magnetic nano-thin film. The insulating film 540 is a nano-thin film of an insulator. As long as a magnetic tunnel junction structure can be formed, the materials of the magnetic film 530 and the insulating film 540 are not particularly limited. For example, the magnetic film 530 can be made of cobalt iron boron, or a 3d transition metal ferromagnetic material such as Fe, Co, or Ni, or an alloy containing these. The insulating film 540 can be made of silicon oxide, silicon nitride, aluminum oxide, magnesium oxide, or the like.

[0090] The upstream electrode 510 and the downstream electrode 520 are electrodes for applying a voltage to the magnetic tunnel junction structure. In the examples of FIGS. 11 to 13, a current flows from the upstream electrode 510 to the downstream electrode 520. For example, in the case of FIG. 11(c), when a voltage is applied between the upstream electrode 510 and the downstream electrode 520, electrons flow from the upper magnetic film 530 to the lower magnetic film 530, passing through the insulating film 540. This is a phenomenon called the "tunnel effect", and the electrical resistance when electrons pass through the insulating film 540 is called the "tunnel resistance". In the examples of FIGS. 11 to 13, the junctions of the electrodes are structured such that the ends are processed so that no current flows that short-circuits the magnetic tunnel junction structure.

[0091] When strain is applied to the detection element 500 through the substrate 110 or the like, a magnetic change occurs in the tunnel junction structure. More specifically, the magnetization directions of the upper and lower magnetic films 530 are shifted. When the magnetization directions of the upper and lower magnetic films 530 are shifted in this way, the tunnel resistance becomes larger than when the magnetization directions are parallel (tunnel magnetoresistance effect). Therefore, in the detection element 500 having the above-mentioned configuration, the current flowing between the electrodes becomes smaller according to the magnitude of the strain of the detection element 500 (more precisely, the magnetic tunnel junction part). That is, as the strain increases, the electric resistance increases. In this way, the detection element 500 can detect the strain based on the current value for the applied voltage. Therefore, by attaching the detection element 500 to the substrate 110, the pressure applied to the transport roller 120 can be measured.

[0092] The detection element having the magnetic tunnel junction structure is not limited to the example shown in FIG. 11. For example, detection elements 600 and 700 shown in FIG. 12 and FIG. 13 can be adopted. The detection element 600 shown in FIG. 12 and the detection element 700 shown in FIG. 13 are both configured with an upstream electrode 510, a downstream electrode 520, a magnetic film 530, and an insulating film 540, and the principle of detecting strain by these configurations is the same as that of the detection element 500. The basic operation of the detection elements 600 and 700 is also the same as that of the detection element 500. The grid directions of the detection elements 500, 600, and 700 correspond to the y-axis direction (the positive direction of the y-axis and the negative direction of the y-axis) in FIG. 11 to FIG. 13, respectively. As shown in the figure, the detection element 600 shown in FIG. 12 has a structure in which the upper magnetic film 530 and the upper magnetic film 530 are partially connected to each other. That is, a magnetic tunnel junction structure is formed only in a partial region of the magnetic film 530, and a tunnel magnetoresistance effect occurs in this structure. Meanwhile, the detection element 700 shown in Fig. 13 is attached to the base material 110 via a substrate 710. As shown in Figs. 11 to 13, the design of the detection element may be appropriately changed according to the required size, durability, magnitude of the stress to be detected, and the like, as long as it does not exceed the above-mentioned principle.

[0093] The roller body 121 according to this embodiment may basically have the same configuration and material as the roller body 121 according to the first and second embodiments. However, it is more preferable that the conveying roller 120 is made of a non-magnetic material. The conveying roller 120 according to this embodiment may be made of, for example, non-magnetic stainless steel. The detection elements 500, 600, and 700 may have a substantially flat plate shape such as a film type as the whole element. This allows the detection element 500 to be easily attached to the base material 110. The detection elements 500, 600, and 700 may have a structure for applying a weak magnetic field to the structural part of the magnetic tunnel junction, such as a drive coil. By applying a magnetic field to the structural part of the magnetic tunnel junction, the tunnel magnetoresistance effect described above can be measured more stably, and therefore the strain can be detected stably.

[0094] In addition, the "upstream electrode" and the "downstream electrode" in the detection elements 500, 600, and 700 are names for convenience, and the direction of current flow may be reversed. That is, the detection elements 500, 600, and 700 shown in Figs. 11 to 13 may be designed so that the current flows from the downstream electrode 520 to the upstream electrode 510.

[0095] In the web transport device 100 and web transport system 100a according to this embodiment, pressure is applied to the transport roller 120 due to the tension of the web 110 when the web 110 is transported. This pressure causes strain in the roller body 121 of the transport roller 120. The transport roller 120 is equipped with a strain sensor equipped with a strain gauge, and the detection element 500, 600, or 700 of the strain gauge can detect a magnetic change that occurs in the magnetic tunnel junction structure due to the strain in the roller body 121.

[0096] Moreover, the strain gauge including the detection elements 500, 600, and 700 according to this embodiment can be arranged in any of the arrangement positions shown in the first and second embodiments. Therefore, the detection elements 500, 600, and 700 utilizing the magnetic tunnel effect can be used to detect the strain of the roller body 121 in the same manner as when a resistor strain gauge is used. Therefore, the strain gauge according to this embodiment has the same effects as the strain gauge 1 according to the first and second embodiments.

[0097] <Modification> In each of the above embodiments, the axial eccentricity specifying unit 178 may (i) specify the direction and magnitude of the axial eccentricity of the conveying roller 120, and (ii) continuously calculate the operation of the driving unit 162 for reducing the specified direction and magnitude of the axial eccentricity in real time or at predetermined time intervals while the conveying roller 120 is in operation. Then, the shaft angle control unit 179 may continuously control the driving unit 162 in real time or at predetermined time intervals according to the calculation result of the shaft eccentricity specifying unit 178. That is, the shaft angle control unit 179 may continuously control the shaft angle of the conveying roller 120 in real time or at predetermined time intervals while the conveying roller 120 is in operation. This makes it possible to keep the axial eccentricity smaller while the conveying roller 120 is in operation.

[0098] The reference value in each of the above embodiments may be actual data stored in the web conveying device 100 when the conveying roller 120 is operated under desirable conditions. In this case, the control device 170 of the web conveying device 100 is connected to another input device such as a personal computer by wire or wirelessly. The control device 170 includes an input receiving unit that receives a predetermined instruction input from a user from the input device. When the input receiving unit receives a predetermined instruction input, the control device 170 stores the output value of the strain sensor acquired by itself in a storage unit (e.g., HDD 174) as a reference value for the strain sensor. This makes it possible to set the output value when the device is actually operated under ideal conditions as the reference value.

[0099] In each of the above embodiments, a recess having substantially the same shape and thickness as the strain sensor may be provided in the roller body 121, and the strain sensor may be fitted into the recess. In this case, it is desirable that the wiring from the strain sensor can also be embedded in the recess. Embedding the strain sensor in the recess in this manner can reduce unevenness when the strain sensor is attached to the roller body 121. An appropriate cover or overcoat may be applied over the strain sensor installed in the recess to eliminate unevenness between the installation portion of the strain sensor and the roller body 121.

[0100] The above describes preferred embodiments and the like. However, the web transport device and transport system according to the present disclosure are not limited to the above-described embodiments. For example, various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0101] 1 strain gauge, 10, 110 substrate, 10a upper surface, 20 functional layer, 30 resistor, 30e1, 30e2 termination, 31 elongated portion, 32 folded portion, 40 wiring, 50 electrode, 60 cover layer, 100 web conveying device, 100a web conveying system, 110 web, 120 conveying roller, 120A to 120C strain sensor, 121 roller body, 123 shaft, 124 first joint portion, 1241 ball portion, 125 second joint portion, 1251 ball portion, 160 roller adjustment mechanism, 161 ball receiving portion, 162 drive portion, 170, 200 control device (input receiving portion, acquisition portion), 171 CPU, 172 ROM, 173 RAM, 174 HDD, 175, 176 Input / output I / F, 177 input section, 178 shaft eccentricity determination section, 179 shaft angle control section, 300, 500, 600, 700 detection element

Claims

1. a conveying roller for conveying the web; an annular strain sensor provided in a circumferential direction on a surface of the conveying roller; a shaft angle control unit that controls the shaft angle of the transport roller based on the output value of the strain sensor.

2. 2. The web transport device of claim 1, wherein the annular strain sensor comprises a plurality of strain gauges arranged circumferentially on the surface of the transport roller.

3. The web transport device according to claim 1 , wherein the annular strain sensor is an annular strain gauge disposed on the surface of the transport roller.

4. 4. The web transport device according to claim 1, wherein the transport roller is provided with a plurality of the annular strain sensors in the axial direction.

5. 4. The web transport device according to claim 1, wherein the shaft angle control section continuously controls the shaft angle of the transport roller in real time or at predetermined time intervals.

6. The web conveying device according to any one of claims 1 to 3, wherein the shaft angle control unit controls the shaft angle of the conveying roller so that the output value of the annular strain sensor matches or approaches a predetermined reference value.

7. The web transport device according to claim 6 , wherein the reference value indicates an output value of the annular strain sensor when no axial eccentricity occurs in the transport roller.

8. an input receiving unit that receives a predetermined instruction input from an input device; an acquisition unit that acquires an output value of the annular strain sensor, The web conveying device according to claim 6, wherein when the input receiving unit receives the specified instruction input, the shaft angle control unit stores the output value of the strain sensor acquired by the acquisition unit in a memory unit as the reference value.

9. a plurality of conveying rollers each having a circumferentially annular strain sensor provided on its surface; a control device that individually controls the shaft angles of the plurality of conveying rollers based on the output value of the strain sensor.

10. the annular strain sensor includes a strain gauge disposed on a surface of the conveying roller; the sensing element of the strain gauge includes a magnetic material; The web conveying device according to any one of claims 1 to 3, wherein the detection element is a detection element that detects a change in the strength of magnetization of the magnetic body when stress is applied to the magnetic body due to deformation of the conveying roller.

11. the annular strain sensor includes a strain gauge disposed on a surface of the conveying roller; the detection element of the strain gauge includes a magnetic tunnel junction structure in which an insulating film is sandwiched between magnetic films, 4. The web transport device according to claim 1, wherein the detection element detects a magnetic change that occurs in the structure due to deformation of the transport roller.

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