Film Thickness Measurement Device, Film Thickness Measurement System, and Film Thickness Measurement Method

Abstract

To provide a film thickness measurement device, a film thickness measurement system, and a film thickness measurement method which are less likely to be affected by a temperature change than the conventional ones.SOLUTION: A film thickness measurement device includes a measurement unit. The measurement unit measures a film thickness by calculating a difference between a first outer diameter of a roll that transports a sheet-like member in contact with an outer peripheral surface of the roll and a sum of the film thickness of the sheet-like member at a portion where the sheet-like member and the roll are in contact with each other and a second outer diameter of the roll. The film thickness measurement device of the embodiment may further include a calculation unit. The calculation unit calculates a first amount indicating a magnitude of an influence of a temperature change of the roll on the measurement of the film thickness by using an amplitude of a periodic fluctuation of the outer diameter of the roll, and calculates, using a minimum value of the periodic fluctuation, a second amount indicating a magnitude of an influence of a temperature change of a distance measurement device that measures the first outer diameter and the sum on the measurement of the film thickness.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a film thickness measurement device, a film thickness measurement system, and a film thickness measurement method. [Background technology]

[0002] There are in-line measurement devices that use optical displacement meters to measure the film thickness of a web. One such in-line measurement device uses a pair of displacement sensors positioned on either side of the web to calculate the web thickness based on the distance from each sensor to the web. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-101656 Summary of the Invention [Problem to be solved by the invention]

[0004] In such in-line measuring devices using a pair of displacement sensors, the expansion and contraction of the frame due to temperature changes directly affects the web thickness measurement. Although there are techniques such as feedback to the measurement value by monitoring the temperature of the frame, the accuracy is low and it cannot handle temperature shifts in the sensor itself.

[0005] An object of the present invention is to provide a film thickness measurement device, a film thickness measurement system, and a film thickness measurement method that are less susceptible to temperature changes than conventional devices. [Means for solving the problem]

[0006] The film thickness measuring device according to the embodiment includes a measuring unit that measures the film thickness by calculating the difference between a first outer diameter of the roll that transports the sheet-like member in contact with the outer peripheral surface of the roll and the sum of the film thickness of the sheet-like member at the portion where the sheet-like member contacts the roll and a second outer diameter of the roll. [Effects of the Invention]

[0007] The present invention enables film thickness measurement that is less susceptible to temperature changes than conventional methods. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of a measurement system according to an embodiment and a main configuration of components included in the measurement system. [Figure 2] 10A and 10B are diagrams showing a method for measuring the film thickness of a web using a sensor unit and a guide roll according to an embodiment. [Figure 3] 2 is a flowchart showing an example of processing by a processor in FIG. 1; [Figure 4] 6 is a graph showing an example of a change in diameter of a guide roll over time. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a measurement system according to an embodiment will be described with reference to the drawings. Note that the scale of each part in each drawing used in the following description of the embodiment may be changed as appropriate. Also, for the sake of explanation, each drawing used in the following description of the embodiment may omit the configuration. Also, in each drawing and in this specification, the same reference numerals indicate similar elements. FIG. 1 is a block diagram showing an example of a measurement system 1 according to an embodiment and a configuration of the main components included in the measurement system 1. As an example, the measurement system 1 includes a measurement device 100, a sensor unit 200, and a guide roll 300. Note that the measurement system 1 may include some of these. The measurement system 1 is a system that measures the film thickness of a web 400. Note that the measurement system 1 is an example of a film thickness measurement system.

[0010] The measuring device 100 is a device that measures the film thickness of the web 400. The measuring device 100 is a general-purpose device such as a server, PC, tablet terminal, or smartphone. Alternatively, the measuring device 100 may be a device dedicated to the measurement system 1. The measuring device 100 includes, for example, a processor 101, a ROM (read-only memory) 102, a RAM (random-access memory) 103, an auxiliary storage device 104, a control interface 105, an input device 106, and a display device 107. A bus 108 or the like connects these components. Note that each component of the measuring device 100 may be built-in or external. Note that the measuring device 100 is an example of a film thickness measuring device.

[0011] The processor 101 is the central part of a computer that performs various calculations and processes, such as calculations and controls, necessary for the operation of the measuring device 100. The processor 101 may be, for example, a central processing unit (CPU), a microprocessing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 101 may be a combination of several of these. The processor 101 may also be a combination of these with a hardware accelerator or the like. The processor 101 controls each component to realize various functions of the measuring device 100 based on programs such as firmware, system software, and application software stored in the ROM 102 or the auxiliary storage device 104. The processor 101 also executes the processes described below based on the programs. Note that some or all of the programs may be incorporated into the circuitry of the processor 101.

[0012] The ROM 102 and RAM 103 are the main storage devices of the computer centered around the processor 101. The ROM 102 is a non-volatile memory used exclusively for reading data. The ROM 102 stores, for example, firmware among the above programs. The ROM 102 also stores data used by the processor 101 when it performs various processes.

[0013] The RAM 103 is a memory used for reading and writing data. The RAM 103 is used as a work area for storing data that is temporarily used when the processor 101 performs various processes. The RAM 103 is typically a volatile memory.

[0014] The auxiliary storage device 104 is an auxiliary storage device of a computer centered around the processor 101. The auxiliary storage device 104 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), or a flash memory. The auxiliary storage device 104 stores, for example, system software and application software among the above programs. The auxiliary storage device 104 also stores data used by the processor 101 when performing various processes, data generated by the processes in the processor 101, various setting values, and the like.

[0015] The control interface 105 is an interface through which the measurement device 100 communicates with the sensor unit 200. The measurement device 100 controls the sensor unit 200 via the control interface 105.

[0016] The input device 106 accepts operations by an operator of the measurement apparatus 100. The input device 106 is, for example, a keyboard, a keypad, a touchpad, a mouse, a controller, etc. The input device 106 may also be a device for voice input.

[0017] Display device 107 displays a screen for notifying various pieces of information to the operator of measuring device 100 or the like. Display device 107 is, for example, a display such as a liquid crystal display or an organic EL (electro-luminescence) display. A touch panel can also be used as input device 106 and display device 107. That is, a display panel included in the touch panel can be used as display device 107, and a pointing device for touch input included in the touch panel can be used as input device 106.

[0018] The bus 108 includes a control bus, an address bus, a data bus, etc., and transmits signals exchanged between the various components of the measuring device 100 .

[0019] The sensor unit 200, the guide roll 300, and the web 400 will be described with reference to Fig. 2. Fig. 2 is a diagram showing a method for measuring the film thickness d of the web 400 using the sensor unit 200 and the guide roll 300 according to the embodiment.

[0020] The sensor unit 200 is a device that uses multiple sensors 201 to measure the distance from each sensor 201 to an object. The sensor unit 200 includes, for example, a sensor 201 and a frame 202. The sensor unit 200 includes four sensors 201: a first sensor 201a, a second sensor 201b, a third sensor 201c, and a fourth sensor 201d. Note that communication between the sensor unit 200 and the measuring device 100 is performed, for example, by each sensor 201 individually communicating with the measuring device 100. Alternatively, the sensor unit 200 may include a communication device. The sensor unit 200 communicates with the measuring device 100 using the communication device.

[0021] The sensor 201 is a sensor capable of measuring distance. The sensor 201 is, for example, a displacement sensor that measures the distance from the sensor 201 to an object. The sensor 201 is typically an optical displacement sensor. However, the sensor 201 may be a displacement sensor of another type, such as an ultrasonic type, a capacitance type, a contact type, or an eddy current type.

[0022] The first sensor 201a and the second sensor 201b face each other with the guide roll 300 and the web 400 sandwiched between them. The first sensor 201a is on the side closer to the web 400. The second sensor 201b is on the side closer to the guide roll 300. The object to be measured by the first sensor 201a is the web 400. The first sensor 201a measures a distance s1 from point P1 to point Q1. Point P1 indicates the position of the first sensor 201a. Point Q1 is a point on the surface of the web 400 opposite the portion where the web 400 and the guide roll 300 contact each other.

[0023] The measurement target of the second sensor 201b, the third sensor 201c, and the fourth sensor 201d is the guide roll 300. The second sensor 201b measures a distance s2 from point P2 to point Q2. Point P2 indicates the position of the second sensor 201b. Point Q2 is a point on the surface of the guide roll 300. More specifically, point Q2 is the point closer to the second sensor 201b among the intersections of a line L12 connecting points P1 and P2 and the surface of the guide roll 300. Note that the line L12 preferably passes through the rotation axis C of the guide roll 300. Therefore, it is preferable that both the first sensor 201a and the second sensor 201b face in the direction of the rotation axis C. Note that the distance between the first sensor 201a and the second sensor 201b, i.e., the distance between points P1 and P2, is referred to as distance s12.

[0024] The third sensor 201c and the fourth sensor 201d face each other across the guide roll 300. There is no web 400 between the third sensor 201c and the fourth sensor 201d. The third sensor 201c measures a distance s3 from point P3 to point Q3. Point P3 indicates the position of the third sensor 201c. Point Q3 is a point on the surface of the guide roll 300. More specifically, point Q3 is the point closer to the third sensor 201c among the intersections of a line L34 connecting points P3 and P4 and the surface of the guide roll 300. Point P4 indicates the position of the fourth sensor 201d.

[0025] The fourth sensor 201d measures a distance s4 from point P4 to point Q4. Point Q4 is a point on the surface of the guide roll 300. More specifically, point Q4 is the point closer to the fourth sensor 201d among the intersections of line L34 and the surface of the guide roll 300. It is preferable that line L34 passes through the rotation axis C of the guide roll 300. Therefore, it is preferable that both the third sensor 201c and the fourth sensor 201d face in the direction of the rotation axis C. It is preferable that the distance between the third sensor 201c and the fourth sensor 201d, i.e., the distance between point P3 and point P4, is referred to as distance s34. Distance s12 and distance s34 may be different, but are preferably the same.

[0026] It is preferable that both the straight lines L12 and L34 are perpendicular to the rotation axis C. Furthermore, it is preferable that the angle θ formed by the straight lines L12 and L34 is perpendicular. However, the angle θ does not necessarily have to be perpendicular. It is preferable that the straight lines L12 and L34 intersect.

[0027] The frame 202 is a member that fixes the four sensors 201 so that the four sensors 201 are in the positional relationship described above. The material of the frame 202 is not limited, but may be, for example, metal or resin. The material of the frame 202 is preferably one that is less likely to deform due to temperature changes.

[0028] The third sensor 201c and the fourth sensor 201d are a pair of sensors that face each other with the roll in between. Therefore, the third sensor 201c and the fourth sensor 201d are an example of a first distance measurement device. The first sensor 201a and the second sensor 201b are a pair of sensors that face each other perpendicularly to the first distance measurement device with the roll and the sheet-like member in between. Therefore, the first sensor 201a and the second sensor 201b are an example of a second distance measurement device.

[0029] The guide roll 300 is used to transport the web 400. The guide roll 300 is rotatable around a rotation axis C. The guide roll 300 is, for example, a free roll that rotates as the web 400 is transported. Alternatively, the guide roll 300 may be rotated by power from a motor or the like to transport the web 400. The guide roll 300 has, for example, a cylindrical shape. Therefore, the outer periphery of the cross section of the guide roll 300 is, for example, a circle. However, the outer periphery of the cross section of the guide roll 300 may deviate from a perfect circle due to errors such as tolerances. The shape of the outer periphery of the cross section of the guide roll 300 is not limited to a circle, but may also be an ellipse. Furthermore, the shape of the outer periphery of the cross section of the guide roll 300 may be another simple closed curve. However, the shape of the outer periphery of the cross section of the guide roll 300 is preferably closer to a circle, because the more the shape is away from a circle, the more difficult it is to transport the web 400. 2, the rotation direction RD of the guide roll 300 is the direction from point Q3 to point Q1. The guide roll 300 is an example of a roll that transports a sheet-like member in contact with the outer circumferential surface of the roll.

[0030] The web 400 is a sheet-like transport object. The web 400 is, for example, a metal foil, a resin sheet, or any other sheet-like object. As an example, the web 400 is a sheet-like positive electrode for an all-solid-state battery. The web 400 is an example of a sheet-like member.

[0031] The operation of the measurement system 1 according to the embodiment will be described below with reference to Fig. 3 and other figures. Note that the processing content in the following operation description is an example, and various processing that can obtain similar results can be used as appropriate. Fig. 3 is a flowchart showing an example of processing by the processor 101 of the measurement device 100. The processor 101 executes the processing of Fig. 3 based on a program stored in, for example, the ROM 102 or the auxiliary storage device 104.

[0032] The processor 110 of the measuring device 100 executes the process shown in FIG. 3 when measuring the film thickness of the web 400.

[0033] 3, the processor 101 of the measuring device 100 starts acquiring measurement information. The measurement information is information indicating the measurement results of each sensor 201. The measurement information includes distances s1 to s4. The processor 101 acquires the measurement information from the sensor unit 200 via the control interface 105.

[0034] In step ST12, the processor 101 measures the film thickness d of the web 400. The processor 101 measures the film thickness d by calculating the film thickness d using the measurement information acquired in step ST11.

[0035] The processor 101 can calculate the film thickness d, for example, using the following formula. d=(D12+d)-D34 (1)

[0036] Here, the diameter D12 is the diameter of the guide roll 300 in the direction of the straight line L12. Also, the diameter D34 is the diameter of the guide roll 300 in the direction of the straight line L34. Therefore, (D12+d)=(s12-s1-s2) (2) D34=(s34-s3-s4) (3) It should be noted that the diameter D34 is an example of a first diameter, and the diameter D12 is an example of a second diameter.

[0037] From the above, equation (1) can be expressed as follows: d=(s12-s1-s2)-(s34-s3-s4) (4)

[0038] When s12 and s34 are equal, the processor 101 can calculate the film thickness d by the following formula: d=(s3+s4)-(s1+s2) (5)

[0039] Note that the straight lines L12 and L34 are offset by an angle θ. Therefore, in equation (4) or (5), the processor 101 uses the average value of the measured values ​​over a predetermined period for distances s1 to s4. The predetermined period is, for example, a predetermined length of time or a period during which the guide roll 300 rotates a predetermined angle. The time is preferably the time during which the guide roll 300 rotates an angle that is a multiple of 360 degrees. The angle is preferably a multiple of 360 degrees. Using the average value can reduce the effect of the offset in angle θ.

[0040] Each of D34 and (s3+s4) is an example of a quantity indicating the first outer diameter. Each of (D12+d) and (s1+s2) is an example of a quantity indicating the sum of the second outer diameter and the film thickness.

[0041] Alternatively, the processor 101 may use the distances s3 and s4 measured at the first measurement timing and the distances s1 and s2 measured at the second measurement timing in equations (4) and (5). The second measurement timing is the timing at which the guide roll 300 rotates by the angle θ after the first measurement timing.

[0042] Diameter D34 is an example of a first outer diameter. Diameter D12 is an example of a second outer diameter. Therefore, equations (1), (4), and (5) are each an example of a mathematical formula for calculating the difference between the first outer diameter, the sum of the second outer diameter, and the film thickness. Therefore, by performing the processing of step ST12, processor 101 functions as an example of a measurement unit that measures film thickness by calculating the difference between the first outer diameter of the roll that transports the sheet-like member while it is in contact with the outer peripheral surface of the roll, and the sum of the film thickness of the sheet-like member at the portion where the sheet-like member and the roll are in contact and the second outer diameter of the roll.

[0043] In step ST13, the processor 101 calculates the temperature influence amount n and the temperature influence amount m. The temperature influence amount n is an amount that indicates the magnitude of the influence on the measurement value due to the temperature change of the guide roll 300 and the frame 202. The temperature influence amount m is an amount that indicates the magnitude of the influence on the measurement value due to the temperature change of the sensor 201.

[0044] The diameter D34 exhibits a change as shown in graph GR in FIG. 4 . FIG. 4 is a graph showing an example of the change over time in the diameter D34 of the guide roll 300. This graph shows the case where the temperatures of the guide roll 300, the frame 202, and the sensor 201 increase. In the graph shown in FIG. 4 , the vertical axis represents the diameter and the horizontal axis represents time. Note that in the example shown in FIG. 4 , the outer periphery of the cross section of the guide roll 300 is assumed to be elliptical. Therefore, the diameter D34 exhibits a periodic waveform as the guide roll 300 rotates. This period corresponds to one rotation of the guide roll. If the outer periphery of the cross section of the guide roll 300 has an uneven shape due to an error, the waveform will be more complex. In FIG. 4 , the amplitude AM of graph GR increases over time. This is thought to indicate that the guide roll 300 and the frame 202 are deforming due to temperature changes. The amplitude AM increases as the temperatures of the guide roll 300 and the frame 202 increase. The processor 110 calculates the amplitude AM and uses this value as the temperature influence amount n1. Alternatively, the processor 110 may use a value indicating how many times the amplitude is larger than the reference amplitude as the temperature influence amount n2. That is, n2=(amplitude AM) / (reference amplitude) (6) The temperature influence amount n2 indicates that the guide roll 300 and the frame 202 have expanded by n2 times. Note that the temperature influence amount n1 and the temperature influence amount n2 are both examples of the temperature influence amount n.

[0045] 4, the minimum value MI and maximum value MA of the waveform of graph GR increase over time. These increases are based on the combined effects of temperature changes in the sensor 201 and temperature changes in the guide roll 300 and frame 202. In other words, the minimum value MI increases as the temperature of the sensor 201 increases.

[0046] For example, if the minimum value MI1 changes to MI2 and the maximum value MA1 changes to MA2, n2(MA1)+m1=MA2 (7) n2(MI1)+m1=MI2 (8) Here, m1 indicates that the diameter of the guide roll 300 is measured to be larger by m1 due to the temperature change of the sensor. Solving this simultaneous equation gives m1=(MA1·MI2-MA2·MI1) / (MA1-MI1) (9) n2=(MA2-MI2) / (MA1-MI1) (10) The processor 110 uses the solution m1 of this simultaneous equation as the temperature influence quantity m1. The processor 110 may use predetermined reference values ​​as MI1 and MA1. In this case, (MA1-MI1) is the reference amplitude. The processor 110 may ignore the influence of temperature changes on the guide roll 300 and the frame 202 and use MI2 or (MI2 / MI1) as the temperature influence quantity m2. The temperature influence quantity m1 and the temperature influence quantity m2 are both examples of the temperature influence quantity m.

[0047] Graph GR shows an example of the periodic fluctuation of the roll outer diameter. Amplitude AM shows an example of the amplitude of the periodic fluctuation of the roll outer diameter. Temperature influence amount n is an example of a first quantity that indicates the magnitude of the influence of roll temperature change on the measurement of the normal film thickness from the amplitude of the periodic fluctuation of the roll outer diameter. Temperature influence amount m is an example of a second quantity that indicates the magnitude of the influence of temperature change of the distance measuring device that measures the first outer diameter and the total from the minimum value of the periodic fluctuation on the measurement of the normal film thickness. Therefore, by performing the processing of step ST13, processor 101 functions as an example of a calculation unit that calculates the first quantity and the second quantity.

[0048] In step ST14, the processor 101 determines whether at least one of the temperature influence quantity n and the temperature influence quantity m is outside the predetermined range. For example, the processor 110 determines that the temperature influence quantity n is outside the predetermined range when the temperature influence quantity n is equal to or less than the threshold value TH1 or equal to or greater than the threshold value TH2. The threshold value TH2 is greater than the threshold value TH1. The threshold value TH1 indicates that the deformation of the guide roll 300 and the frame 202 due to the temperature of the guide roll 300 and the frame 202 being too low is greater than a predetermined value. The threshold value TH2 indicates that the deformation of the guide roll 300 and the frame 202 due to the temperature of the guide roll 300 and the frame 202 being too high is greater than a predetermined value. For example, the processor 110 determines that the temperature influence quantity m is outside the predetermined range when the temperature influence quantity m is equal to or less than the threshold value TH3 or equal to or greater than the threshold value TH4. The threshold value TH4 is greater than the threshold value TH3. The threshold value TH3 indicates that the influence on the measurement value due to the temperature of the sensor 201 being too low is greater than a predetermined value. Threshold value TH4 is a threshold value indicating that the influence on the measurement value due to the temperature of sensor 201 being too high is greater than a predetermined value. If both temperature influence amount n and temperature influence amount m are within the predetermined range, processor 101 determines No in step ST14 and returns to step ST12. On the other hand, if at least one of temperature influence amount n and temperature influence amount m is outside the predetermined range, processor 101 determines Yes in step ST14 and proceeds to step ST15.

[0049] In step ST15, based on the determination result of step ST14, the processor 101 notifies that at least one of an error indicating that the temperatures of the guide roll 300 and the frame 202 are outside a predetermined range and an error indicating that the temperature of the sensor 201 is outside a predetermined range has occurred. To this end, the processor 101 generates, for example, an image corresponding to an error screen. Then, the processor 101 instructs the display device 107 to display the generated image. Upon receiving the display instruction, the display device 107 displays the error screen. The error screen is a screen indicating that the error has occurred. After processing step ST15, the processor 101 returns to step ST12.

[0050] The measurement system 1 of the embodiment measures the film thickness d by calculating the difference between the diameter D34 and the sum of the diameter D12 and the film thickness d. When the temperature of the guide roll 300 changes, the diameter D34 and the diameter D12 change in the same manner. Therefore, the measurement system 1 of the embodiment is less susceptible to temperature changes affecting the measurement of the film thickness d than conventional systems. Furthermore, the diameters D34 and D12 are offset by an angle θ, but represent the diameters of the same guide roll 300, and therefore fluctuate in the same period with only a phase difference. Therefore, the measurement system 1 of the embodiment is less susceptible to the influence on the measurement of the film thickness d caused by the guide roll 300 being out of round than conventional systems.

[0051] In the measurement system 1 of the embodiment, a battery positive electrode sheet is used as the web 400, as an example. Battery positive electrode sheets are only several tens of micrometers thick, and film thickness measurement is significantly affected by temperature shifts in the sensor 201 and thermal expansion and contraction of the frame 202. The measurement system 1 of the embodiment is suitable for measuring film thicknesses on the order of micrometers, such as those of battery positive electrode sheets. The measurement system 1 of the embodiment can accurately measure the thickness of the web 400 being transported at high speed in-line. Furthermore, the measurement system 1 of the embodiment can also be used to measure the thickness of a sheet of positive electrode material formed by coating a substrate with positive electrode slurry and drying it in-line, or to measure the film thickness after pressing in a subsequent roll press process.

[0052] Furthermore, the measurement system 1 of the embodiment calculates a temperature influence amount n and a temperature influence amount m. The temperature influence amount n indicates the influence of a temperature change of the guide roll 300 on the measurement of the film thickness d. The temperature influence amount m indicates the influence of a temperature change of the sensor 201 on the measurement of the film thickness d. Therefore, the measurement system 1 of the embodiment can evaluate the influence of the temperature change of the guide roll 300 and the temperature change of the sensor 201 on the measurement of the film thickness d separately. Furthermore, by using the temperature influence amount n and the temperature influence amount m, the measurement system 1 of the embodiment can notify the user when the influence of temperature on the measurement of the film thickness d is greater than a predetermined value.

[0053] Furthermore, the measurement system 1 of the embodiment includes a third sensor 201c and a fourth sensor 201d that measure the diameter D34 or (distance s3 + distance s4). The measurement system 1 of the embodiment also includes a first sensor 201a and a second sensor 201b that measure (diameter D12 + film thickness d) or (distance s1 + distance s2). This allows the measurement system 1 of the embodiment to simultaneously measure the diameter D34 or (distance s3 + distance s4) and (diameter D12 + film thickness d) or (distance s1 + distance s2).

[0054] In the measurement system 1 of the embodiment, the angle θ is preferably perpendicular. By making the angle θ perpendicular, the measurement system 1 of the embodiment can suppress the influence of temperature changes in the frame 202 on the measurement of the film thickness d.

[0055] The above embodiment can be modified as follows. The measurement system 1 may include a device in which the measurement device 100 and the sensor unit 200 are integrated.

[0056] Each device in the embodiment may be composed of a plurality of devices, and each device in the embodiment may be realized using cloud computing.

[0057] The processor 101 may implement some or all of the processes implemented by the programs in the above embodiments by a hardware circuit configuration.

[0058] A program for implementing the processes of the embodiments may be transferred in a state where it is stored in a non-transitory computer-readable storage medium within the device. However, the device may also be transferred without the program stored therein. The program may then be transferred separately and written to the device. In this case, the program may be transferred by, for example, recording it on a removable non-transitory computer-readable storage medium or by downloading it via a network such as the Internet or a local area network (LAN).

[0059] Although the embodiments of the present invention have been described above, they are merely examples and are not intended to limit the scope of the present invention. The embodiments of the present invention can be implemented in various forms without departing from the spirit of the present invention. [Explanation of symbols]

[0060] 1. Measurement System 100 Measuring Device 101 processors 102 ROM 103 RAM 104 Auxiliary storage 105 Control Interface 106 Input Devices 107 Display Devices 108 Bus 200 Sensor Unit 201a 1st Sensor 201b Second Sensor 201c 3rd sensor 201d 4th sensor 202 frames 300 Guide Roll 400 Web

Claims

1. a measuring unit that measures the film thickness by calculating the difference between a first outer diameter of the roll that conveys the sheet-like member while the sheet-like member is in contact with the outer peripheral surface of the roll and the sum of the film thickness of the sheet-like member at the portion where the sheet-like member and the roll are in contact and a second outer diameter of the roll; a calculation unit that calculates a first quantity indicating the magnitude of the effect of temperature changes on the measurement of the normal film thickness using the amplitude of the periodic fluctuation of the outer diameter of the roll, and calculates a second quantity that indicates the magnitude of the effect of temperature changes on the measurement of the normal film thickness using the minimum value of the periodic fluctuation.

2. A film thickness measurement system, a distance measuring device and a film thickness measuring device; the distance measuring device measures a first outer diameter of the roll that conveys the sheet-like member in contact with the outer peripheral surface of the roll, and a sum of a film thickness of the sheet-like member at a portion where the sheet-like member and the roll are in contact and a second outer diameter of the roll; the film thickness measuring device includes a measuring unit that measures the film thickness by calculating a difference between the first outer diameter and the total outer diameter; the film thickness measurement system includes a first distance measurement device and a second distance measurement device different from the first distance measurement device; the first distance measuring device measures a quantity indicative of the first outer diameter; The second distance measuring device measures a quantity indicative of the sum.

3. The first distance measuring device is a pair of sensors facing each other across the roll, 3. The film thickness measurement system according to claim 2, wherein the second distance measurement device is a pair of sensors that face the first distance measurement device so as to be perpendicular to the first distance measurement device, with the roll and the sheet-like member sandwiched between them.

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