Fixture, measurement head and displacement meter device

Abstract

To arrange multiple optical axes of multiple measurement heads with higher density while enabling position adjustment of the optical axis for each of the multiple measurement heads.SOLUTION: A fixture 400 includes: a head holding section that holds a measurement head 1A; and a base housing that is configured to be attachable to an installation surface and supports the head holding section so as to be movable on one surface perpendicular to an optical axis of the measurement head held by the head holding section. The fixture 400 includes: a first adjustment screw which moves the head holding section supported on the base housing in a first adjustment direction D1; and a second adjustment screw which moves the head holding section in a second adjustment direction D2 different from the first adjustment direction D1. The multiple fixtures 400 can be arranged side by side in a predetermined array direction (e.g., Y direction) in a common posture. The first adjustment direction D1 and the second adjustment direction D2 intersect each other in the array direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a mounting fixture for mounting a measuring head for measuring a physical quantity on an installation surface, a measuring head that is mounted on an installation surface using the mounting fixture, and a displacement gauge device equipped with the measuring head. [Background technology]

[0002] As an example of a device for measuring the displacement of the surface of a measurement object in a non-contact manner, there is a confocal displacement meter equipped with a white light source, an optical fiber, and a measurement head. In the confocal displacement meter, light in a wide wavelength band (white light) generated by the white light source is guided to the measurement head through the optical fiber. The measurement head includes an optical system (e.g., multiple lenses) and a main housing that houses the optical system, and irradiates the measurement object with the light guided through the optical fiber through the optical system. At this time, chromatic aberration occurs in the light irradiated to the measurement object by the multiple lenses. In addition, the measurement head receives the light that is focused and reflected by the surface of the measurement object. The displacement of the surface of the measurement object is measured based on the light received by the measurement head.

[0003] There is a known method for measuring the thickness of an object by placing two measuring heads facing each other across the object. In this method, in order to measure the thickness of the object with high accuracy, it is required to accurately align the optical axis of the optical system of one measuring head with the optical axis of the optical system of the other measuring head.

[0004] Patent Document 1 describes a holding device that holds each measuring head in an adjustable manner in position and attitude in order to accurately measure the thickness of a measurement target. The holding device has a configuration in which a plurality of members that support the measuring head so that the measuring head can be moved and rotated in a plurality of directions are provided on a single base. Furthermore, the holding device is provided with a plurality of knobs for moving or rotating the measuring head in a plurality of directions. This allows a user to adjust the position and attitude of each measuring head by attaching the base to a desired installation surface and operating the plurality of knobs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-203866 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when measuring the thickness of multiple parts of the measurement object, it is preferable to prepare multiple sets of measurement headsets, each of which corresponds to one of the multiple parts of the measurement object, with two measurement heads as one measurement headset. In this case, the thicknesses of the multiple parts of the measurement object are measured simultaneously using the multiple measurement headsets. This improves the efficiency of thickness measurement compared to the case where one measurement headset is moved to the multiple parts of the measurement object in sequence to measure the thickness.

[0007] As described above, in order to simultaneously measure the thickness of multiple parts of the measurement object using multiple measurement headsets, it is necessary to appropriately arrange the multiple measurement headsets at positions corresponding to the multiple parts of the measurement object. In addition, in order to measure the thickness of more parts of the measurement object, it is preferable to arrange the optical axes of the multiple measurement heads at a high density.

[0008] However, each of the multiple measurement heads is held by a holding device. Therefore, the density at which the optical axes of the multiple measurement heads can be arranged is limited to the extent that the multiple holding devices do not interfere with each other. In addition, the holding device for the measurement head described in Patent Document 1 includes multiple knobs that are operated by the user. Therefore, a working space is required around each knob for the user to operate the knob. Securing such a working space makes it more difficult to densely arrange the optical axes of the multiple measurement heads.

[0009] An object of the present invention is to provide a mounting fixture that enables the position adjustment of the optical axis for each of the multiple measurement heads while allowing the multiple optical axes of the multiple measurement heads to be arranged with higher density, a measurement head that can be mounted on an installation surface using the mounting fixture, and a displacement meter device that is equipped with the measurement head. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a mounting fixture for mounting a measurement head having an optical axis extending in one direction and for acquiring a physical quantity related to a measurement object placed on the optical axis, on an installation surface, the mounting fixture comprising: a head holding part for holding the measurement head; a base housing configured to be mountable on the installation surface and supporting the head holding part movably on a surface perpendicular to the optical axis of the measurement head held by the head holding part; a first adjustment screw for moving the head holding part supported by the base housing in a first adjustment direction on the surface; The base housing is configured so that a plurality of base housings including the base housing can be arranged in a common posture on the installation surface in a predetermined arrangement direction, and each of the first adjustment direction and the second adjustment direction intersects with the arrangement direction when the plurality of base housings are arranged in the arrangement direction on the installation surface in a common posture.

[0011] A measurement head according to another aspect of the present invention is a measurement head that is attached to the above-mentioned mounting fixture as the first measurement head or the second measurement head and has an optical system holding part that holds an optical system corresponding to the optical axis, and the optical system and the optical system holding part are configured so that when the holding position of the measurement head by the frame body and the mounting fixture changes on the optical axis as the temperature environment changes when measuring the thickness of the measurement object using the frame body, errors in the measurement result of the thickness of the measurement object that would occur due to changes in the holding position of the measurement head are offset.

[0012] A displacement meter device according to yet another aspect of the present invention includes the first measuring head, the second measuring head, a coincidence determination unit that determines a degree of coincidence indicating the degree to which an optical axis of the first measuring head and an optical axis of the second measuring head coincide based on an intensity of light emitted from one of the first measuring head and the second measuring head and incident on the other measuring head while the first measuring head and the second measuring head are arranged opposite each other, and an information communication unit that transmits a result of the coincidence determination by the coincidence determination unit to a predetermined external device. Effect of the Invention

[0013] According to the present invention, it is possible to adjust the position of the optical axis for each of the multiple measurement heads, and it is also possible to arrange the multiple optical axes of the multiple measurement heads with higher density. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing a configuration of a confocal displacement meter according to an embodiment of the present invention. [Diagram 2] FIG. 13 is a diagram showing an example of a specific configuration for measuring the thickness of a measurement object being transported using a plurality of measuring heads. [Diagram 3] 3 is a side view of the configuration including the frame in FIG. 2 as viewed along the X direction. [Figure 4]3 is a diagram for explaining an operation for adjusting the positions of the optical axes of the plurality of measuring heads attached to the frame of FIG. 2. FIG. [Diagram 5] 3 is an exploded perspective view of a fixture provided to the first beam portion of FIG. 2. FIG. [Figure 6] 6 is a plan view, one side view, and one end view of the first main body portion of FIG. 5. [Figure 7] FIG. 6 is a bottom view of the first main body portion of FIG. 5. [Figure 8] 6 is a plan view, one side view, and one end view of the second main body portion of FIG. 5. [Figure 9] FIG. 6 is a bottom view of the second body portion of FIG. 5. [Figure 10] 6 is a plan view, one side view, and one end view of the head holding part in FIG. 5. [Figure 11] 6 is a bottom view of the head holding portion of FIG. 5. [Figure 12] 6 is a plan view of the rotational force blocking member of FIG. 5. [Figure 13] 6 is a diagram for explaining a procedure for attaching a measurement head to the lower surface of the first beam portion in FIG. 3 using the fixture in FIG. 5. FIG. [Figure 14] 4 is an external perspective view showing two mounting fixtures provided adjacent to the first beam portion of FIG. 3. FIG. [Figure 15] FIG. 15 is a horizontal cross-sectional view of the two fixtures of FIG. 14, shown cut by a horizontal imaginary plane. [Figure 16] 3 is an exploded perspective view of a fixture provided to the second beam portion of FIG. 2. FIG. [Figure 17] 17 is a diagram for explaining a procedure for attaching a measurement head onto the upper surface of the second beam portion in FIG. 3 using the fixture in FIG. 16. FIG. [Figure 18] 10 is a block diagram showing a functional configuration realized in a PC by executing a coincidence degree communication program. FIG. [Figure 19] 13 is a flowchart of a matching degree communication process based on a matching degree communication program. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The measuring head according to the present invention has an optical axis extending in one direction and is used to obtain a physical quantity related to a measurement object placed on the optical axis. The mounting fixture according to the present invention is a jig for mounting the measuring head on, for example, a predetermined installation surface. Hereinafter, the mounting fixture and measuring head according to one embodiment of the present invention will be described with reference to the drawings.

[0016] In the following, as an example of a measurement head, a measurement head for a confocal displacement meter that acquires, as a physical quantity, the distance from the measurement head to a measurement object placed on the optical axis of the measurement head will be described.

[0017] 1. Configuration of a confocal displacement meter equipped with a measurement head First, the configuration of a confocal displacement meter equipped with a measurement head will be described. Fig. 1 is a schematic diagram showing the configuration of a confocal displacement meter according to an embodiment of the present invention. As shown in Fig. 1, a confocal displacement meter 9 includes measurement heads 1A and 1B, measurement units 100A and 100B, light guiding sections 300A and 300B, a control unit 2, and a PC (personal computer) 3. The light guiding section 300A includes a plurality of optical fibers, and optically connects the measurement head 1A to some of the components inside the measurement unit 100A (light projecting section 120 and spectroscopic section 130, which will be described later).

[0018] The measurement unit 100A includes a unit housing 110, a light projecting section 120, a spectroscopic section 130, a light receiving section 140, a measurement control section 150, and a sub-display section 190. The unit housing 110 accommodates the light projecting section 120, the spectroscopic section 130, the light receiving section 140, and the measurement control section 150. The sub-display section 190 includes a display such as a 7-segment display or a dot matrix display, and is attached to the unit housing 110. The light projecting section 120 has a white light source that generates light in a wide and continuous wavelength band (for example, 500 nm to 700 nm), i.e., light having a plurality of continuous wavelengths (white light), and is configured to be able to emit the light generated from the white light source. The light emitted by the light projecting section 120 is input to an optical fiber 311 (described later) of the light guide section 300A.

[0019] The spectroscopic section 130 includes a diffraction grating 131 and a plurality of (two in this example) lenses 132 and 133. As described later, a part of the light emitted by the light projecting section 120 and reflected by the surface of the measurement target S is output from an optical fiber 312 of the light guiding section 300A, which will be described later. The light output from the optical fiber 312 is approximately parallelized by passing through the lens 132 and is incident on the diffraction grating 131. In this embodiment, the diffraction grating 131 is a reflective diffraction grating. The light incident on the diffraction grating 131 is split so as to be reflected at different angles for each wavelength, and is focused on a one-dimensional position that differs for each wavelength by passing through the lens 133.

[0020] The light receiving unit 140 includes an imaging element (one-dimensional line sensor) in which a plurality of pixels are arranged one-dimensionally. The imaging element may be a multi-segment PD (photodiode), a CCD (charge-coupled device) camera, a CMOS (complementary metal-oxide semiconductor) image sensor, or other elements. The light receiving unit 140 is arranged so that a plurality of pixels of the imaging element receive light at a plurality of focusing positions different for each wavelength formed by the lens 133 of the spectroscopic unit 130. Each pixel of the light receiving unit 140 outputs an analog electrical signal (hereinafter referred to as a light receiving signal) corresponding to the amount of light received. The light receiving signal indicates the intensity of the light received by each pixel.

[0021] The measurement control section 150 includes a CPU (Central Processing Unit) and a memory or a microcomputer. A control program is stored in the measurement control section 150, and various data such as measurement conditions used in displacement measurement are also stored in the measurement control section 150. These data are provided from a control unit 2 described later. The measurement control section 150 controls the light projecting section 120 and the light receiving section 140 based on the stored control program and data, and calculates the displacement of the surface of the measurement target S based on the light receiving signal output by the light receiving section 140. The measurement control section 150 causes the sub-display section 190 to display the displacement calculation result.

[0022] The measurement control section 150 is connected to the control unit 2, and the control unit 2 is further connected to the PC 3. The measurement control section 150 provides the displacement calculation result and the light receiving signal output from the light receiving section 140 to the control unit 2. The configurations and operations of the control unit 2 and the PC 3 will be described later.

[0023] The measurement head 1A includes a head housing 10, a fiber receptacle 30, and a plurality of (four in this example) lenses 221, 222, 223, and 224, and has a cylindrical outer circumferential surface. The head housing 10 houses the plurality of lenses 221, 222, 223, and 224, and constitutes the outer shape of the measurement head 1A.

[0024] A fiber receptacle 30 is attached to the head housing 10. A fiber connector 330 (described later) of the light guiding unit 300A is connected to the fiber receptacle 30. The fiber connector 330 holds one end of an optical fiber 319 (described later) of the light guiding unit 300A.

[0025] Light is guided from the measurement unit 100A to the optical fiber 319 through the light guide section 300A. The light guided to the optical fiber 319 is output from the optical fiber 319 in the head housing 10 of the measurement head 1A and passes through the lenses 221, 222, 223, and 224 in this order. In this embodiment, each of the lenses 221, 222, 223, and 224 is made of a single glass member. The lens 221 is a magnifying lens that magnifies the light guided from the optical fiber 319. The lenses 222 and 223 are bending lenses that add a predetermined function to the light magnified by the lens 221 and converge the light. The lens 224 is a chromatic aberration lens that generates chromatic aberration in the light guided from the lens 223. The light that has generated chromatic aberration by passing through the lenses 221, 222, 223, and 224 is focused at a position near the surface of the measurement target S.

[0026] The light guiding section 300A includes optical fibers 311, 312, and 319, a fiber coupler 320, and a fiber connector 330. In the example of Fig. 1, the fiber coupler 320 is provided in the unit housing 110 of the measurement unit 100A. The fiber connector 330 is connected to the measurement head 1A as described above.

[0027] The fiber coupler 320 has a so-called 2×2 type configuration, and includes four ports 321 to 323 and a main body 324. In FIG. 1, one of the four ports is not shown. The ports 321, 322 and the port 323 are connected to the main body 324 so as to face each other with the main body 324 in between. Light input to at least one of the ports 321 and 322 is output from the port 323. Light input to the port 323 is output from each of the ports 321 and 322.

[0028] The optical fibers 311 and 312 are connected to ports 321 and 322, respectively, of the fiber coupler 320. The other end of the optical fiber 319 is connected to a port 323 of the fiber coupler 320.

[0029] According to this configuration, light emitted by light-projecting unit 120 of measurement unit 100A is input to port 321 of fiber coupler 320 through optical fiber 311. The light input to port 321 is output from port 323 and guided to measurement head 1A through optical fiber 319. The light guided to measurement head 1A is irradiated onto measurement object S through multiple lenses 221, 222, 223, and 224.

[0030] A portion of the light reflected by the surface of the measurement object S is input to one end of the optical fiber 319 through the multiple lenses 224, 223, 222, and 221. The light input to one end of the optical fiber 319 is input to a port 323 of the fiber coupler 320. The light input to the port 323 is output from the ports 321 and 322. The light output from the port 322 is guided to the spectroscopic section 130 through the optical fiber 312. In this way, the displacement of the measurement object S is calculated based on the light irradiated from the measurement unit 100A to the measurement object S.

[0031] The measurement units 100A and 100B have the same configuration, the measurement heads 1A and 1B have the same configuration, and the light guides 300A and 300B have the same configuration. The measurement head 1B and some of the components inside the measurement unit 100B are optically connected by the light guide 300B, similar to the example of the connection between the measurement head 1A and the measurement unit 100A described above. In addition, the measurement control unit 150 (not shown) of the measurement unit 100B is connected to the control unit 2.

[0032] Light emitted from a light-projecting section 120 (not shown) of the measurement unit 100B is irradiated onto the measurement object S through the measurement head 1B. A part of the light reflected on the surface of the measurement object S is returned to the measurement unit 100B through the measurement head 1B. Thereby, the displacement of the measurement object S is calculated based on the light irradiated onto the measurement object S from the measurement head 1B. In this case, a measurement control section 150 (not shown) provided in the measurement unit 100B provides the displacement calculation result and a light receiving signal output from the light receiving section 140 to the control unit 2.

[0033] The control unit 2 includes a CPU and a memory, or a microcomputer. For example, measurement conditions for displacement in the measurement units 100A and 100B are input to the control unit 2 from the PC 3. The measurement conditions include, for example, the amount of light emitted by the light projector 120, the timing of light emission from the light projector 120, and the amount of exposure in the light receiver 140. The control unit 2 provides the input measurement conditions to the measurement control unit 150 of each of the measurement units 100A and 100B. As a result, each of the measurement units 100A and 100B performs a measurement operation based on the given measurement conditions.

[0034] The PC 3 includes a CPU 3a and a memory 3b. The memory 3b stores various programs related to thickness measurement of the measurement target S, which will be described later, as well as various data used in thickness measurement. The CPU 3a executes the programs stored in the memory 3b. The displacement calculation results and light receiving signals provided from each of the measurement units 100A and 100B to the control unit 2 are provided from the control unit 2 to the PC 3.

[0035] A main display unit 4a and an operation unit 4b are connected to the PC 3. The main display unit 4a includes a display device such as an organic EL (electroluminescence) panel or a liquid crystal display panel. The operation unit 4b includes a keyboard and a pointing device. The pointing device includes a mouse, a joystick, or the like. A user can give various instructions related to thickness measurement to the PC 3 by operating the operation unit 4b.

[0036] In the above-mentioned confocal displacement meter 9, as shown in Fig. 1, the measurement heads 1A and 1B are arranged to face each other with the measurement object S in between. The measurement object S has one side and the other side opposite each other. In this state, if the distance between the measurement heads 1A and 1B (the head-to-head distance) is known, the thickness of the measurement object S can be measured based on the displacement of the one side and the other side of the measurement object S measured by the measurement units 100A and 100B and the head-to-head distance.

[0037] 2. Example of thickness measurement of the measurement target S using the confocal displacement meter 9 in Figure 1 Measuring the thickness of the measurement target S using two measuring heads 1A and 1B can be effectively used to inspect the thickness of a sheet-like molded product (in-line inspection) at a production site such as a factory. For example, a sheet-like molded product is transported on a linear conveying path at a production site. A pair of measuring heads 1A and 1B are arranged at a measurement position on the conveying path so as to face each other with the molded product in between. In this case, it becomes possible to efficiently measure the thickness of a portion of the molded product that passes through the measurement position on the conveying path.

[0038] When multiple sets of measuring heads 1A, 1B are arranged at multiple measurement positions on the transport path, the thicknesses of multiple parts of the molded product passing through the multiple measurement positions on the transport path can be measured. In this case, by arranging the multiple measurement positions in a direction intersecting the transport direction of the molded product, it becomes possible to measure the thicknesses of many parts of the molded product.

[0039] Fig. 2 is a diagram showing an example of a specific configuration for measuring the thickness of a measurement object S during transportation using a plurality of sets of measurement heads 1A, 1B. As shown by the dot pattern in Fig. 2, the measurement object S, the thickness of which is to be measured in this example, is a sheet-like molded product (a band-like molded product) that extends in one direction with a constant width. The molded product is transported in the direction in which the molded product extends within a horizontal plane (see the thick solid arrow in Fig. 2).

[0040] In order to measure the thickness of multiple portions of the measurement object S being transported, in other words, to arrange multiple sets of measurement heads 1A, 1B at multiple measurement positions on the transport path of the measurement object S, the frame 900 is used. In FIG. 2 and certain figures described later, arrows indicating mutually orthogonal X, Y, and Z directions are provided to clarify the positional relationship between the measurement object S, the frame 900, and other components. The X direction is parallel to the transport direction of the measurement object S, and the Y direction is a direction orthogonal to the X direction in a horizontal plane. The Z direction corresponds to the vertical direction.

[0041] The frame 900 is a single member formed of a metal material such as stainless steel, and has a first beam portion 910, a second beam portion 920, and two pillar portions 930. The first beam portion 910 and the second beam portion 920 both extend in the Y direction and are arranged to be aligned at an interval in the Z direction. The first beam portion 910 is located above the second beam portion 920. One of the two pillar portions 930 extends in the Z direction and connects one end of the first beam portion 910 to one end of the second beam portion 920. The other of the two pillar portions 930 extends in the Z direction and connects the other end of the first beam portion 910 to the other end of the second beam portion 920. Moreover, the frame 900 is supported by two frame support members 950 so that the measurement target S passes through a space surrounded by the first beam portion 910, the second beam portion 920 and the two pillar portions 930.

[0042] A first beam portion 910 of the frame body 900 is provided with a plurality of (seven in this example) mounting portions 919 for mounting the measuring head 1A of Fig. 1, arranged substantially continuously in the Y direction. The measuring head 1A can be mounted to each mounting portion 919 via a mounting fixture 400. The mounting fixture 400 will be described in detail later.

[0043] 1 are provided on the second beam portion 920 of the frame body 900 so as to be aligned substantially continuously in the Y direction. The measuring head 1B can be attached to each of the attachment portions 929 via a mounting fixture 500. The mounting fixture 500 will be described in detail later.

[0044] In the Z direction, the multiple mounting parts 919 of the first beam part 910 face the multiple mounting parts 929 of the second beam part 920, respectively. By attaching a pair of measuring heads 1A, 1B to each pair of mounting parts facing each other in the Z direction among the multiple mounting parts 919, 929, it is possible to measure the thickness of a portion of the measurement object S located between each pair of measuring heads 1A, 1B. In the example of FIG. 2, two pairs of measuring heads 1A, 1B are attached to two pairs of mounting parts facing each other in the Z direction among the multiple mounting parts 919, 929 of the frame body 900, respectively. This makes it possible to simultaneously measure the thicknesses of two portions of the measurement object S located between the two pairs of measuring heads 1A, 1B.

[0045] Fig. 3 is a side view of the configuration including the frame 900 of Fig. 2, viewed along the X direction. In Fig. 3, an enlarged view showing the attachment state of multiple measurement heads 1A to the first beam portion 910 is shown in a dotted line balloon. Also, an enlarged view showing the attachment state of multiple measurement heads 1B to the second beam portion 920 is shown in a dashed line balloon.

[0046] As shown in the dotted line in FIG. 3, the first beam portion 910 has an upper surface 911 and a lower surface 912. In the first beam portion 910, the lower surface 912 serves as a mounting surface for mounting a plurality of measurement heads 1A. As described later, the measurement heads 1A are held by some components (head holding portion 460 in FIG. 5 described later) included in the mounting tool 400. In this state, the mounting tool 400 is placed on the lower surface 912 of the first beam portion 910 and screwed to the first beam portion 910 using a plurality of (for example, three) screws. Therefore, a plurality of through holes 913 are formed in the plurality of mounting portions 919 of the first beam portion 910 for screwing the mounting tool 400 from the upper surface 911 through the inside of the first beam portion 910. The inner diameter of each through hole 913 near the lower end is formed smaller than the head of the screw so that the screw inserted from above does not pass downward. Furthermore, as shown by a two-dot chain line in a dotted bubble, each mounting portion 919 of the first beam portion 910 has a through hole 914 formed therein that allows a user to access the mounting fixture 400 from above when the mounting fixture 400 is attached to the mounting portion 919. The through hole 914 also functions as a path for drawing the optical fiber 319 extending from the measuring head 1A outward from the frame body 900 when the measuring head 1A is attached to the mounting portion 919.

[0047] As shown in the dashed line in FIG. 3, the second beam portion 920 has an upper surface 921 and a lower surface 922. In the second beam portion 920, the upper surface 921 serves as a mounting surface for mounting the multiple measurement heads 1B. As described later, the measurement heads 1B are held by some components (a pedestal portion 510 and a holding piece 550 in FIG. 16 described later) of the mounting tool 500. In this state, the mounting tool 500 is placed on the upper surface 921 of the second beam portion 920 and screwed to the second beam portion 920 using multiple (e.g., three) screws. Therefore, multiple mounting portions 929 of the second beam portion 920 are formed with multiple through holes 923 for screwing the mounting tool 500 from the lower surface 922 through the inside of the second beam portion 920. Each through hole 923 is formed so that the inner diameter near the upper end is smaller than the head of the screw so that the screw inserted from below does not pass upward. Furthermore, as shown by a two-dot chain line in a dashed-dotted line balloon, each mounting portion 929 of the second beam portion 920 has a through hole 924 formed therein that allows a user to access the mounting fixture 500 from below when the mounting fixture 500 is attached to the mounting portion 929. The through hole 924 also functions as a path for drawing the optical fiber 319 extending from the measuring head 1B outward from the frame 900 when the measuring head 1B is attached to the mounting portion 929.

[0048] Here, when the multiple lenses 221, 222, 223, and 224 (FIG. 1) of each of the measurement heads 1A and 1B are regarded as one optical system, the optical axis of the one optical system is referred to as the optical axis of the measurement heads 1A and 1B.

[0049] The mounting fixture 400 and the frame 900 are configured so that, when the measuring head 1A is attached to the frame 900, the optical axis of the measuring head 1A extends parallel to the Z direction. Moreover, the mounting fixture 500 and the frame 900 are configured so that, when the measuring head 1B is attached to the frame 900, the optical axis of the measuring head 1B extends parallel to the Z direction.

[0050] As explained in the background art, in order to measure the thickness of a measurement target S with high accuracy using two measurement heads 1A and 1B, it is necessary to accurately align the optical axis of one measurement head 1A with the optical axis of the other measurement head 1B. Therefore, the mounting fixture 400 according to this embodiment is configured so that, with the measurement head 1A attached to the frame 900, the position of the optical axis of the measurement head 1A can be adjusted within a plane perpendicular to the optical axis.

[0051] Fig. 4 is a diagram for explaining an operation for adjusting the position of each optical axis of a plurality of measuring heads 1A attached to the frame 900 of Fig. 2. Fig. 4 shows a plan view of the two mounting fixtures 400 and the two measuring heads 1A seen through the frame 900.

[0052] In this example, a plurality of measuring heads 1A are attached to a plurality of mounting portions 919 of the first beam portion 910 via a plurality of mounting fixtures 400. Therefore, the plurality of mounting fixtures 400 are lined up in the Y direction on the lower surface 912 of the first beam portion 910. In this state, each mounting fixture 400 is configured so that a user can adjust the position of the optical axis LA of the measuring head 1A by operating two adjustment screws s2 in FIG. 5, which will be described later, from two directions inclined with respect to the X direction and the Y direction in a horizontal plane, as shown by hollow arrows AA1 and AA2 in FIG. 4.

[0053] In this case, as shown in the speech bubble in Fig. 4, for example, when a user performs an adjustment operation along the direction indicated by the outline arrow AA1, the position of the optical axis LA is adjusted in a first adjustment direction D1 along the arrow AA1. Also, for example, when a user performs an adjustment operation along the direction indicated by the outline arrow AA2, the position of the optical axis LA is adjusted in a second adjustment direction D2 along the arrow AA2.

[0054] As described above, each fixture 400 can adjust the position of the optical axis LA of the measurement head 1A from a direction inclined with respect to the arrangement direction (Y direction) of the multiple fixtures 400 and the direction perpendicular thereto (X direction) in a horizontal plane. This eliminates the need to provide a work space between the multiple fixtures 400 for adjusting the position of the optical axis LA. In addition, as shown by the dashed line in FIG. 4, the user can stand in areas AR1 and AR2 adjacent to the transport path of the measurement target S in a plan view and adjacent to the frame body 900. In this case, by facing each fixture 400, the user can easily match the direction in which the user faces with the direction of the position adjustment work of the optical axis LA. This makes it easier to adjust the position of the optical axis LA.

[0055] 3. Details of mounting fixture 400 (a) Schematic of the configuration of the fixture 400 FIG. 5 is an exploded perspective view of the fixture 400 provided on the first beam 910 of FIG. 2. In FIG. 5 and certain figures described later, arrows are attached to indicate mutually orthogonal x, y, and z directions in order to clarify the positional relationship between the multiple components of the fixture 400. In the following description, the direction of the x direction indicated by the arrow x on the drawing is appropriately referred to as the +x direction, and the opposite direction is appropriately referred to as the -x direction. In the y direction, the direction of the arrow y on the drawing is appropriately referred to as the +y direction, and the opposite direction is appropriately referred to as the -y direction. In addition, in the z direction, the direction of the arrow z on the drawing is appropriately referred to as the +z direction, and the opposite direction is appropriately referred to as the -z direction.

[0056] 5, mounting tool 400 mainly includes base housing 410, head holding part 460, and rotational force blocking member 480, and is produced by connecting these multiple parts. Base housing 410 is further composed of first main body part 420 and second main body part 440. First, the structures of first main body part 420, second main body part 440, head holding part 460, and rotational force blocking member 480 will be described.

[0057] (b) First main body portion 420 Fig. 6 is a plan view, one side view, and one end view of the first main body portion 420 of Fig. 5. Fig. 7 is a bottom view of the first main body portion 420 of Fig. 5. In Figs. 6 and 7, the plan view is a view of the first main body portion 420 of Fig. 5 seen in the -z direction, and one side view is a view of the first main body portion 420 of Fig. 5 seen in the -y direction. Moreover, one end view is a view of the first main body portion 420 of Fig. 5 seen in the -x direction, and the bottom view is a view of the first main body portion 420 of Fig. 5 seen in the +z direction.

[0058] The first main body 420 is a single member made of a metal material such as stainless steel, and includes a plate-shaped portion 421, a first end face forming portion 431, and a second end face forming portion 432, as shown in Fig. 6. The plate-shaped portion 421 has a generally rectangular shape that is slightly longer in the x direction in a plan view, and has a constant thickness in the z direction. The first end face forming portion 431 and the second end face forming portion 432 are formed to extend a constant distance in the +z direction from both ends of the plate-shaped portion 421 in the x direction.

[0059] The plate-shaped portion 421 has one surface 422 facing the +z direction and the other surface 423 facing the -z direction. The one surface 422 of the plate-shaped portion 421 is located between the first end surface forming portion 431 and the second end surface forming portion 432 in the x direction. The one surface 422 is processed to be flat so that unevenness is reduced as much as possible. A circular head opening 424 into which the measurement head 1A can be inserted is formed in the center of the plate-shaped portion 421. In addition, two screw holes 425 are formed in the plate-shaped portion 421 so as to sandwich the head opening 424 in the longitudinal direction of the plate-shaped portion 421. The two screw holes 425 open in the +z direction.

[0060] The first end face forming portion 431 is formed in a plate shape having a constant thickness in the x direction. Two through holes 431h are formed in the approximate center in the z direction of the first end face forming portion 431. Each through hole 431h extends in a direction inclined with respect to the x direction and the y direction in plan view. A protrusion 431p is formed in the center in the y direction at the tip end of the first end face forming portion 431 in the z direction. A screw hole sha is formed in the center of the protrusion 431p in plan view. Two screw holes shb are formed in the portion (both end portions) of the tip end of the first end face forming portion 431 excluding the protrusion 431p.

[0061] The second end face forming portion 432 is formed in a plate shape having a certain thickness in the x direction, similar to the first end face forming portion 431. In addition, two through holes 432h are formed in the approximate center in the z direction of the second end face forming portion 432, similar to the first end face forming portion 431. Each through hole 432h extends in a direction inclined with respect to the x direction and the y direction in a plan view. In addition, two protrusions 432p are formed at both ends in the y direction at the tip end of the second end face forming portion 432 in the z direction. In a plan view, a screw hole sha is formed in the center of each protrusion 432p. One screw hole shb is formed in a portion (center portion) of the tip end of the second end face forming portion 432 excluding the two protrusions 432p.

[0062] (c) Second main body portion 440 Fig. 8 is a plan view, one side view, and one end view of the second main body portion 440 of Fig. 5. Fig. 9 is a bottom view of the second main body portion 440 of Fig. 5. In Figs. 8 and 9, the plan view is a view of the second main body portion 440 of Fig. 5 seen in the -z direction, and one side view is a view of the second main body portion 440 of Fig. 5 seen in the -y direction. Moreover, one end view is a view of the second main body portion 440 of Fig. 5 seen in the -x direction, and the bottom view is a view of the second main body portion 440 of Fig. 5 seen in the +z direction.

[0063] The second main body portion 440 is a single member formed of a metal material such as stainless steel, and includes a plate-shaped portion 441, a first side surface forming portion 451, and a second side surface forming portion 452, as shown in Fig. 8. The plate-shaped portion 441 has a substantially rectangular shape that is slightly longer in the x direction in a plan view, and has a constant thickness in the z direction. The first side surface forming portion 451 and the second side surface forming portion 452 are formed so as to extend a constant distance in the -z direction from both side portions of the plate-shaped portion 441 in the Y direction.

[0064] The plate-shaped portion 441 has one surface 442 facing the +z direction and another surface 443 facing the -z direction. A substantially regular hexagonal holder opening 444 into which a tubular portion 461 (FIG. 10) of a head holder 460 described later can be inserted is formed in the center of the plate-shaped portion 441. Two through holes 445 are formed in the plate-shaped portion 441 so as to sandwich the holder opening 444 in the longitudinal direction of the plate-shaped portion 441.

[0065] Furthermore, a notch 446a into which the protrusion 431p (FIG. 6) of the first main body 420 can be fitted is formed in the center in the y direction of the end of the plate-like portion 441 in the +x direction. Two through holes nh are formed in the end of the plate-like portion 441 in the +x direction except for the notch 446a (both end portions).

[0066] Furthermore, two notches 446b into which two protrusions 432p (FIG. 6) of the first main body 420 can be fitted are formed at both ends in the y direction at the end in the -x direction of the plate-like portion 441. One through-hole nh is formed in the portion (center portion) of the end in the -x direction of the plate-like portion 441 excluding the two notches 446b.

[0067] The first side surface forming portion 451 and the second side surface forming portion 452 are formed to accommodate a part of the head holding portion 460 described later in the space in the -z direction from the plate-shaped portion 441. Therefore, the area located between the first side surface forming portion 451 and the second side surface forming portion 452 in plan view is somewhat larger than the outer shape of the head holding portion 460 in plan view.

[0068] The first side surface forming portion 451 basically constitutes a side surface portion of the second main body portion 440 facing the +y direction, and extends in the x direction. The center portion of the first side surface forming portion 451 in the x direction is bent so as to bulge in the +y direction along a part of the inner edge of the holding portion opening 444 in a plan view, and includes a first wall portion w1 and a third wall portion w3 that are inclined with respect to the x direction and the y direction. A screw hole shc is formed in approximately the center of each of the first wall portion w1 and the third wall portion w3.

[0069] The second side surface forming portion 452 basically constitutes a side surface portion of the second main body portion 440 facing the -y direction, and extends in the x direction. The center portion of the second side surface forming portion 452 in the x direction is bent so as to bulge in the -y direction along the other portion of the inner edge of the holding portion opening 444 in a plan view, and includes a second wall portion w2 and a fourth wall portion w4 that are inclined with respect to the x direction and the y direction. A spring accommodating portion sf capable of accommodating a spring is formed in the approximate center of each of the second wall portion w2 and the fourth wall portion w4.

[0070] In a plan view, the first wall portion w1 of the first side surface forming portion 451 and the second wall portion w2 of the second side surface forming portion 452 face each other across the holding portion opening 444. Also, the third wall portion w3 of the first side surface forming portion 451 and the fourth wall portion w4 of the second side surface forming portion 452 face each other across the holding portion opening 444.

[0071] 9, adjustment screws s2 are screwed into two screw holes shc formed in the first wall portion w1 and the third wall portion w3 of the first side surface forming portion 451, respectively, during the process of assembling the mounting tool 400. Springs sp are housed in two spring accommodating portions sf formed in the third wall portion w3 and the fourth wall portion w4 of the second side surface forming portion 452, respectively, during the process of assembling the mounting tool 400.

[0072] (d) Head holding part 460 Fig. 10 is a plan view, one side view, and one end view of head holding portion 460 in Fig. 5. Fig. 11 is a bottom view of head holding portion 460 in Fig. 5. In Figs. 10 and 11, the plan view is a view of head holding portion 460 in Fig. 5 seen in the -z direction, and one side view is a view of head holding portion 460 in Fig. 5 seen in the -y direction. Moreover, one end view is a view of head holding portion 460 in Fig. 5 seen in the -x direction, and the bottom view is a view of head holding portion 460 in Fig. 5 seen in the +z direction.

[0073] The head holding part 460 is a single member made of a metal material such as stainless steel, and includes a tube part 461 and a plurality of supported parts 464a, 464b, 464c, and 464d, as shown in Fig. 10. The tube part 461 is formed to extend a predetermined distance in the z direction, and has one end part 461a facing the +z direction and the other end part 461b facing the -z direction. The tube part 461 has a cylindrical inner circumferential surface that is slightly larger than the outer circumferential surface of the measuring head 1A, and has a cylindrical outer circumferential surface whose cross section perpendicular to the axial direction is a regular hexagon or a nearly regular hexagon.

[0074] Here, the tubular portion 461 has a first tubular portion 462 and a second tubular portion 463 arranged in order from one end portion 461a to the other end portion 461b. In the tubular portion 461, a linear notch cc is formed in a portion between the first tubular portion 462 and the second tubular portion 463, extending a certain distance in the circumferential direction of the tubular portion 461. In the plan view of FIG. 10, the range in which the notch cc is formed in the circumferential direction of the tubular portion 461 is indicated by an arrow ARC of a dashed line. As indicated by the arrow ARC, the notch cc in this example is formed over a range of about 3 / 4 of the entire circumference of the tubular portion 461.

[0075] The first cylindrical portion 462 is configured to be able to hold the measuring head 1A of FIG. 1 by tightening the outer circumferential surface of the measuring head 1A when the measuring head 1A is inserted into the cylindrical portion 461. Specifically, the first cylindrical portion 462 has a fastening portion 462b. In the plan view and one end view of FIG. 10, the fastening portion 462b is indicated by a thick dotted frame. The fastening portion 462b is formed so as to separate a part of the first cylindrical portion 462 in the circumferential direction at an interval. Furthermore, the distance between the two separated portions is configured to be adjustable using a screw s5 (FIG. 13) described later.

[0076] The second tube portion 463 is formed so that its length (height) in the z direction is the same as or slightly larger than the length (height) in the Z direction of the second main body portion 440 in Fig. 8. Four supported portions 464a, 464d, 464b, and 464c are provided on the outer circumferential surface of the second tube portion 463 so as to be aligned in this order clockwise in a plan view. The four supported portions 464a, 464d, 464b, and 464c are formed so as to extend a predetermined distance from the other end portion 461b of the tube portion 461 in the +z direction.

[0077] 10, the four supported portions 464a, 464d, 464b, and 464c are disposed at 90° intervals with respect to the axis of the cylindrical portion 461. Therefore, the supported portions 464a and 464b face each other in the x direction with the cylindrical portion 461 therebetween. Also, the supported portions 464c and 464d face each other in the y direction with the cylindrical portion 461 therebetween.

[0078] An end face consisting of the cylindrical portion 461 and the four supported portions 464a, 464d, 464b, and 464c is formed at the other end 461b of the cylindrical portion 461. This end face comes into contact with one surface 422 of the first main body portion 420 when the mounting tool 400 is assembled. For this reason, the end face is machined flat to reduce unevenness as much as possible.

[0079] A through hole 465 is formed in the center of each of the two supported portions 464a, 464b aligned in the x direction in plan view. The two through holes 465 of the head holding portion 460 correspond to the two screw holes 425 of the first main body portion 420 in Fig. 6. The inner diameter of each of the through holes 465 is sufficiently larger than the inner diameter of each of the screw holes 425 of the first main body portion 420. (e) Rotational force blocking member 480 Fig. 12 is a plan view of rotational force blocking member 480 of Fig. 5. The plan view of Fig. 12 is a view of rotational force blocking member 480 of Fig. 5 as viewed in the -z direction. Rotational force blocking member 480 is a single plate-like member made of a metal material such as stainless steel, and is produced, for example, by cutting out a plate-like member (such as a metal plate) having a certain thickness.

[0080] 12, rotational force blocking member 480 includes two screw receiving portions 481 and a connecting portion 482. The two screw receiving portions 481 are aligned in the x direction at an interval. The connecting portion 482 is formed in a broken line shape extending in the x direction while bending so as to bulge in the -y direction in plan view, and connects the two screw receiving portions 481.

[0081] Here, the two screw receiving portions 481 are formed so as to be able to be placed on the two supported portions 464a, 464b of the head holding portion 460 in Fig. 10. Also, the connecting portion 482 is formed so as to be able to bypass a part of the outer periphery of the tube portion 461 in a state in which the two screw receiving portions 481 are placed on the two supported portions 464a, 464b of the head holding portion 460 in Fig. 10.

[0082] Furthermore, a through hole 481h is formed in the approximate center of each of the two screw receiving portions 481. The two through holes 481h are formed so as to overlap with the two through holes 465 of the supported portions 464a, 464b, respectively, in a state in which the two screw receiving portions 481 are placed on the two supported portions 464a, 464b of the head holding portion 460 in FIG.

[0083] Moreover, rotational force blocking member 480 is configured so as to be able to be fitted between first side surface forming portion 451 and second side surface forming portion 452 of second main body portion 440 in Fig. 8. Furthermore, rotational force blocking member 480 is formed so that each screw receiving portion 481 is adjacent to or in contact with first side surface forming portion 451 and second side surface forming portion 452 when rotational force blocking member 480 is fitted into second main body portion 440.

[0084] (f) Assembly of the fixture 400 When assembling the mounting fixture 400, as shown in Fig. 5, first, the head holding part 460 is placed on one surface 422 of the first main body part 420. In addition, the rotational force blocking member 480 is placed on a part of the head holding part 460 so that the two screw receiving parts 481 (Fig. 12) are positioned on the supported parts 464a, 464b (Fig. 10) of the head holding part 460.

[0085] In this state, as shown by the thick dashed arrow in FIG. 5, two fixing screws s1 are screwed into two screw holes 425 (FIG. 6) of the first main body portion 420 through two through holes 481h (FIG. 12) of the rotational force blocking member 480 and two through holes 465 (FIG. 10) of the head holding portion 460, and temporarily tightened. Each fixing screw s1 is a screw with a washer previously assembled therein. Therefore, when the fixing screw s1 is screwed into the screw hole 425, a washer is inevitably disposed between the head of the fixing screw s1 and the rotational force blocking member 480. Note that a screw without a washer assembled therein can also be used as the fixing screw s1. In this case, it is preferable to attach a washer separately to the fixing screw s1.

[0086] Here, as described above, the inner diameter of each through hole 465 of the head holding part 460 is larger than the inner diameter of each screw hole 425 of the first main body part 420. Therefore, in a state in which each fixing screw s1 is temporarily fastened to the corresponding screw hole 425, the head holding part 460 is movable within a small range relative to the first main body part 420. In other words, the head holding part 460 is in a released state in which it is movable relative to the first main body part 420.

[0087] Next, as shown by the thick solid arrow in Fig. 5, metal springs sp are attached to the two spring accommodating portions sf (Fig. 8) of the second main body portion 440. Also, as shown by the thick dotted arrow in Fig. 5, adjustment screws s2 are attached to the two screw holes shc (Fig. 8) of the second main body portion 440. A retaining ring (e.g., an E-ring, not shown) is attached to the adjustment screw s2 to prevent it from coming loose.

[0088] Thereafter, the second body 440 is placed on the first body 420 so as to cover the head holder 460 and the rotational force blocking member 480. At this time, the rotational force blocking member 480 is accommodated in a space surrounded by the first side surface forming portion 451 and the second side surface forming portion 452 (FIG. 8) of the second body 440. Also, a part of the second tubular portion 463 of the head holder 460 and the supported portions 464a to 464d (FIG. 10) are accommodated in a space surrounded by the first side surface forming portion 451 and the second side surface forming portion 452 (FIG. 8) of the second body 440. Also, the protruding portions 431p, 432p (FIG. 6) of the first body 420 are fitted into the notches 446a, 446b (FIG. 8) of the second body 440.

[0089] In this state, the first tube portion 462 of the head holding portion 460 is located on one surface 442 of the second main body portion 440. In addition, the heads of the two fixing screws s1 are exposed on the second main body portion 440 through the two through holes 445 (FIG. 8) of the second main body portion 440. Furthermore, the three through holes nh (FIG. 8) of the second main body portion 440 overlap with the three screw holes shb (FIG. 6) of the first main body portion 420. In addition, the tip surfaces of the protruding portions 431p, 432p (FIG. 6) of the first main body portion 420 are located slightly in the +z direction from the one surface 442 of the second main body portion 440, and are located in a common plane that is parallel to the one surface 442 and perpendicular to the z direction. In other words, the tip portions of the protruding portions 431p, 432p (FIG. 6) slightly protrude from the one surface 442 of the second main body portion 440.

[0090] 5, three screws s3 are screwed into three screw holes shb of the first body portion 420 through three through holes nh of the second body portion 440 and finally tightened. This completes the mounting tool 400.

[0091] (g) Use of the mounting fixture 400 Fig. 13 is a diagram for explaining a procedure for mounting the measuring head 1A on the lower surface 912 of the first beam portion 910 in Fig. 3 using the mounting fixture 400 in Fig. 5. When mounting the measuring head 1A to the frame body 900, first, the mounting fixture 400 is attached to the mounting portion 919 of the first beam portion 910. In Fig. 13, the first beam portion 910 is omitted from illustration.

[0092] When mounting the mounting tool 400 to the first beam portion 910, the tip surfaces of the three protrusions 431p, 432p of the first main body portion 420 are pressed against the lower surface 912 (FIG. 3) of the first beam portion 910. Also, the screw holes sha formed in each of the protrusions 431p, 432p are positioned so as to overlap with any of the multiple through holes 913 (FIG. 3) formed in the first beam portion 910. Then, the mounting tool 400 is screwed onto the lower surface 912.

[0093] Next, as shown in the upper part of FIG. 13, a ring-shaped member RB1 is attached to the rear end vicinity of the measurement head 1A (the fiber receptacle 30 or the vicinity thereof). The ring-shaped member RB1 is made of a metal material such as stainless steel, and includes two semicircular arc members r1 and r2. Therefore, the above attachment work is performed by sandwiching the rear end vicinity of the measurement head 1A between the two members r1 and r2, and connecting both ends of the members r1 and r2 with two screws s4 (see the thick dotted arrows in FIG. 13). The outer diameter of the ring-shaped member RB1 is larger than the maximum outer diameter of the head housing 10 of the measurement head 1A. Thus, the ring-shaped member RB1 attached to the measurement head 1A functions as a flange of the measurement head 1A.

[0094] 13, the measuring head 1A is inserted into the cylindrical portion 461 of the head holding portion 460 through the through hole 914 (FIG. 3) of the first beam portion 910 with the tip portion FE of the measuring head 1A facing downward. At this time, the lower surface of the ring-shaped member RB1 abuts against one end portion 461a of the cylindrical portion 461 of the head holding portion 460. As a result, the measuring head 1A is supported by the head holding portion 460.

[0095] 13, a screw s5 is attached to the fastening portion 462b of the first cylindrical portion 462, and a part of the outer circumferential surface of the measuring head 1A is fastened. As a result, the measuring head 1A is fastened by the first cylindrical portion 462 and held by the head holding portion 460.

[0096] As described above, when the mounting fixture 400 is assembled, neither of the two fixing screws s1 in Fig. 5 is fully tightened. Therefore, in the initial state, the head holding part 460 is in a released state. Therefore, the user can adjust the position of the optical axis LA of the measuring head 1A by moving the head holding part 460 on one surface 422 (Fig. 6) of the first main body part 420.

[0097] Specifically, the user adjusts the amount of screwing of two adjustment screws s2 (FIG. 5) screwed into the second main body portion 440 of the mounting fixture 400. This allows the position of the optical axis LA to be adjusted in the first adjustment direction D1 and the second adjustment direction D2, as described with reference to FIG.

[0098] Furthermore, after completing the position adjustment of the optical axis LA, the user tightens (additionally tightens) the two fixing screws s1 in FIG. 5 from above the attachment 400 through the two through holes 445 (FIG. 8) of the second main body portion 440. This causes the head holding portion 460 to be firmly screwed to the first main body portion 420. In other words, the head holding portion 460 is switched from a released state to a fixed state in which it cannot move relative to the first main body portion 420.

[0099] Here, in the mounting tool 400, the rotational force blocking member 480 is located between the head of the fixing screw s1 and the head holding portion 460. As described above, when the rotational force blocking member 480 is fitted into the second main body portion 440, each screw receiving portion 481 is close to or in contact with the first side surface forming portion 451 and the second side surface forming portion 452. Therefore, the movement or rotation of the rotational force blocking member 480 in the horizontal plane is restricted by the first side surface forming portion 451 and the second side surface forming portion 452, and the rotational force blocking member 480 hardly moves or rotates relative to the second main body portion 440. Therefore, when the fixing screw s1 is fastened, even if the head of the fixing screw s1 rotates in a state where it is in contact with the rotational force blocking member 480, the rotational force blocking member 480 does not rotate. In other words, the head of the fixing screw s1 slides on the rotational force blocking member 480 in the rotation direction of the fixing screw s1. As a result, the rotational force generated at the head of the fixing screw s1 is not transmitted to the head holding part 460 through the rotational force blocking member 480. In this way, when the head holding part 460 is changed from the released state to the fixed state, the rotational force of the fixing screw s1 does not act on the head holding part 460. As a result, when the fixing screw s1 is tightened, the head holding part 460 is prevented from shifting in an unintended direction relative to the first main body part 420.

[0100] If the user wishes to adjust the position of the optical axis LA again, the user loosens the degree of fastening of each fixing screw s1, thereby enabling the user to easily switch the head holding portion 460 from the fixed state to the released state.

[0101] (h) Proximity arrangement of multiple mounting fixtures 400 and adjustment of the position of the optical axis LA In the first beam portion 910 of the frame body 900, the multiple mounting portions 919 are arranged substantially continuously. Thus, when the multiple measuring heads 1A are attached to the multiple mounting portions 919 so as to be arranged continuously, each two adjacent mounting fixtures 400 come into contact with or are close to each other. In this embodiment, the distance between two adjacent mounting fixtures 400 is, for example, greater than 0 mm and equal to or less than 20 mm.

[0102] In this way, even when two mounting fixtures 400 are arranged in contact with or close to each other, the configuration of mounting fixture 400 according to this embodiment does not reduce the efficiency of the work for adjusting the position of optical axis LA for each mounting fixture 400. This point will be described.

[0103] Fig. 14 is an external perspective view showing two mounting fixtures 400 provided adjacent to the first beam portion 910 in Fig. 3, and Fig. 15 is a horizontal cross-sectional view of the two mounting fixtures 400 in Fig. 14, showing a state cut by a horizontal imaginary plane VS. In Fig. 14, the first beam portion 910 is omitted. In the explanation of Figs. 14 and 15, when distinguishing between two mounting fixtures 400 provided adjacent to each other, one mounting fixture 400 will be called a first mounting fixture 400A and the other mounting fixture 400 will be called a second mounting fixture 400B.

[0104] 6 and 7, in the mounting tool 400 according to this embodiment, two through holes 431h, 432h are formed in each of the first end face forming portion 431 and the second end face forming portion 432 of the first main body portion 420. When two mounting tools 400 are arranged closely to each other in the Y direction, these through holes 431h, 432h function as a passage for operating the adjustment screw s2 provided in one mounting tool 400 through the inside of the other mounting tool 400.

[0105] 14 and 15, one of the two through holes 432h formed in the second end face forming portion 432 of the second mounting fixture 400B extends from the end face facing the -X direction of the second end face forming portion 432 toward the first wall portion w1 of the first mounting fixture 400A. This allows the user to insert a tool such as a screwdriver or a wrench into one of the through holes 432h of the second mounting fixture 400B and operate one of the adjustment screws s2 of the first mounting fixture 400A, as shown by the arrow a01 in FIGS.

[0106] Moreover, one of the two through holes 431h formed in the first end face forming portion 431 of the second mounting fixture 400B extends from the end face facing the +X direction of the first end face forming portion 431 toward the third wall portion w3 of the first mounting fixture 400A. This allows the user to insert a tool such as a screwdriver or a wrench into one of the through holes 431h of the second mounting fixture 400B and operate the other adjustment screw s2 of the first mounting fixture 400A, as shown by the arrow a02 in Figures 14 and 15.

[0107] In each mounting fixture 400, the two through holes 431h formed in the first end face forming portion 431 are formed symmetrically with respect to a straight line passing through the center of the mounting fixture 400 along the longitudinal direction of the mounting fixture 400 in a plan view. In addition, the two through holes 432h formed in the second end face forming portion 432 are also formed symmetrically with respect to a straight line passing through the center of the mounting fixture 400 along the longitudinal direction of the mounting fixture 400 in a plan view.

[0108] Therefore, in the examples of Figures 14 and 15, even if a new mounting fixture 400 is provided in the +Y direction of the second mounting fixture 400B and the two adjustment screws s2 of that mounting fixture 400 face in the -Y direction, the user can operate the two adjustment screws s2 of the new mounting fixture 400 by inserting a tool into the other through hole 431h and the other through hole 432h of the second mounting fixture 400B.

[0109] 4. Details of the mounting fixture 500 The details of the fixture 500 in FIG. 2 will be described. FIG. 16 is an exploded perspective view of the fixture 500 provided on the second beam portion 920 in FIG. 2. In FIG. 16, as in the example of FIG. 5, arrows indicating mutually orthogonal x, y, and z directions are added to clarify the positional relationship between the multiple components of the fixture 500. In addition, in the following description, the direction in which the arrow x points on the drawing is appropriately called the +x direction, and the opposite direction is appropriately called the -x direction. In addition, in the y direction, the direction in which the arrow y points on the drawing is appropriately called the +y direction, and the opposite direction is appropriately called the -y direction. Furthermore, in the z direction, the direction in which the arrow z points on the drawing is appropriately called the +z direction, and the opposite direction is appropriately called the -z direction.

[0110] As shown in FIG. 16, the mounting tool 500 mainly includes a base portion 510 and a holding piece 550. The base portion 510 is a single member made of a metal material such as stainless steel, and has a generally rectangular parallelepiped shape that is slightly elongated in the x direction. The base portion 510 is formed with a head opening 519 that penetrates the center of the base portion 510 in the z direction. The head opening 519 is formed in a generally elliptical shape having a major axis in the x direction so that the measurement head 1B can be inserted and the inserted measurement head 1B can be moved a small distance in the x direction. In addition, a portion of the inner circumferential surface that forms the head opening 519 that faces the +x direction is formed in a semi-cylindrical shape extending in the z direction. In the following description, the portion of the inner circumferential surface of the head opening 519 that faces the +x direction is called a head contact surface 519s.

[0111] The base 510 has a support surface 511 and a supported surface 513 that face in opposite directions in the z direction. The support surface 511 faces the +z direction and includes a first support surface 511a and a second support surface 511b that are aligned in the x direction. The first support surface 511a and the second support surface 511b are both flat surfaces perpendicular to the z direction, but have different height positions in the z direction. The first support surface 511a is located in the +z direction from the second support surface 511b. Therefore, two step portions 512 are formed at both ends in the y direction between the first support surface 511a and the second support surface 511b. Screw holes are formed in these step portions 512 for connecting a holding piece 550, which will be described later.

[0112] Three mounting portions 515 are formed on the supported surface 513 facing the -z direction. The three mounting portions 515 are spaced apart from one another and protrude slightly in the -z direction from other portions of the supported surface 513. Each mounting portion 515 is formed with a screw hole for screwing the mounting tool 500 to the mounting portion 929 of the second beam portion 920 (see FIG. 3). The tip surfaces of the three mounting portions 515 are formed so as to be located within a common plane perpendicular to the z direction.

[0113] The holding piece 550 is a substantially rectangular plate-like member formed to have a thickness corresponding to the step portion 512 of the base portion 510 and extend in one direction. The holding piece 550 is configured to be able to be placed on the second support surface 511b of the base portion 510. The center of the side portion constituting one long side of the holding piece 550 is cut in an arc shape. As a result, the holding piece 550 has a concave surface 550s corresponding to the head contact surface 519s of the head opening 519. The concave surface 550s is curved in an arc shape when the holding piece 550 is viewed in the z direction, and has the same or approximately the same radius of curvature as the head contact surface 519s. Furthermore, the holding piece 550 has two through holes extending in the short direction near both ends of the holding piece 550 in the longitudinal direction. These through holes correspond to two screw holes formed in the two step portions 512 of the base portion 510.

[0114] When assembling the mounting fixture 500, the holding piece 550 is placed on the second support surface 511b of the base portion 510 so that the concave surface 550s of the holding piece 550 faces the head contact surface 519s of the base portion 510. In this state, one surface of the holding piece 550 and the height position of the first support surface 511a of the base portion 510 in the z direction coincide with each other.

[0115] Furthermore, two screws s10 are screwed through the two through holes of the holding piece 550 into the screw holes of the two stepped portions 512 of the base portion 510, and temporarily tightened. In this way, the mounting tool 500 is completed.

[0116] Fig. 17 is a diagram for explaining a procedure for mounting the measuring head 1B on the upper surface 921 of the second beam portion 920 in Fig. 3 using the mounting fixture 500 in Fig. 16. When mounting the measuring head 1B to the frame body 900, first, the mounting fixture 500 is attached to the mounting portion 929 of the second beam portion 920. In Fig. 17, the second beam portion 920 is not shown.

[0117] When mounting fixture 500 to second beam portion 920, the tip faces of three mounting portions 515 of supported surface 513 of base portion 510 are pressed against upper surface 921 (FIG. 3) of second beam portion 920. Also, screw holes formed in each of three mounting portions 515 are positioned so as to overlap with any of a plurality of through holes 923 (FIG. 3) formed in second beam portion 920. Then, mounting fixture 500 is screwed onto upper surface 921.

[0118] Next, a ring-shaped member RB2 is prepared as shown in the upper part of Fig. 17. The ring-shaped member RB2 is made of a metal material such as stainless steel, and has a slit in a part in the circumferential direction. The ring-shaped member RB2 is formed with a dimensional tolerance that is sufficient to fit the measuring head 1B, so that the measuring head 1B can be attached (fitted) into the ring-shaped member RB2.

[0119] Next, as shown by the thick dotted arrow in Fig. 17, the prepared ring-shaped member RB2 is attached to the vicinity of the tip FE of the measuring head 1B. This attachment is performed by temporarily elastically deforming the ring-shaped member RB2. The outer diameter of the ring-shaped member RB2 is larger than the maximum outer diameter of the head housing 10 of the measuring head 1B. As a result, the ring-shaped member RB2 attached to the measuring head 1B functions as a flange of the measuring head 1B.

[0120] 17, the measuring head 1B is inserted into the head opening 519 of the base 510 with the tip FE of the measuring head 1B facing upward. At this time, the lower surface of the ring-shaped member RB2 abuts against the first support surface 511a of the base 510 and one surface of the holding piece 550. As a result, the measuring head 1B is supported by the mounting fixture 500.

[0121] Next, two screws s10 that are screwed into the screw holes of the two step portions 512 of the base portion 510 through the two through holes of the holding piece 550 are finally tightened. As a result, a part of the outer circumferential surface of the measuring head 1B is sandwiched between the head contact surface 519s (FIG. 16) of the base portion 510 and the concave surface 550s (FIG. 16) of the holding piece 550, and fixed to the mounting fixture 500. Unlike the mounting fixture 400, the mounting fixture 500 does not have a function of adjusting the position of the optical axis of the measuring head 1B.

[0122] 5. Preferred configuration for measuring the thickness of the measurement object S (a) If the temperature environment changes when measuring the thickness of the object S to be measured using the confocal displacement meter 9, the measurement accuracy may decrease due to the expansion or contraction of each component (frame 900, mounting fixture 400, mounting fixture 500, etc.).

[0123] In order to suppress the deterioration of the measurement accuracy, it is conceivable to construct each component from a material that does not expand or contract due to temperature changes. However, such materials do not exist, or even if they do, they are expensive and it is difficult to use them for the above components. In addition, in order to suppress the deterioration of the measurement accuracy, it is conceivable to form the components from multiple types of materials with different linear expansion coefficients, and to offset the changes in shape between the components when the temperature environment changes. However, it is extremely difficult to set the shapes and dimensions of the components and select the materials for each of the components in the hope of achieving such an effect.

[0124] In addition to the above, in order to suppress the deterioration of the measurement accuracy, a method of performing a correction process on the measurement data according to the expansion or contraction of each component accompanying a change in the temperature environment can be considered. In this case, the appropriate correction process conditions can be determined based on, for example, an estimation of the change in the holding state (holding position, etc.) of the measuring heads 1A and 1B accompanying a change in the temperature environment and the estimation result. However, if different materials are used among the multiple components, it is necessary to consider the difference in the amount of expansion or contraction that occurs among the multiple components. Therefore, it is difficult to grasp the change in the holding state (holding position, etc.) of the measuring heads 1A and 1B accompanying a change in the temperature environment. Therefore, when a method of performing a correction process on the measurement data is adopted, it is preferable that the various components used for measuring the thickness of the measurement target S are formed of the same metal material as much as possible.

[0125] Specifically, the base housing 410, head holding part 460, rotational force blocking member 480, spring sp, and multiple screws (s1, s2, s3) constituting the mounting fixture 400 are preferably made of a common metal material (e.g., stainless steel). The base part 510, holding piece 550, and multiple screws s10 constituting the mounting fixture 500 are also preferably made of a common metal material (e.g., stainless steel). The ring-shaped members RB1, RB2 and screws s10 attached to the measuring heads 1A, 1B are also preferably made of a common metal material (e.g., stainless steel). Furthermore, the frame 900 and the screws attached to the frame 900 are also preferably made of a common metal material (e.g., stainless steel).

[0126] In these cases, since many of the components used to measure the thickness of the measurement target S are made of a common metal material, it is easy to grasp changes in the holding state (holding position, etc.) of the measuring heads 1A and 1B that accompany changes in the temperature environment. Therefore, it becomes possible to apply appropriate correction processing to the measurement data based on errors predicted in advance by simulation, etc.

[0127] (b) The measurement heads 1A and 1B have a configuration in which a plurality of lenses 221, 222, 223, and 224 are housed in a head housing 10. Here, the head housing 10 of each of the measurement heads 1A and 1B expands or contracts with changes in the temperature environment. Furthermore, the optical characteristics (focal length, etc.) of each of the plurality of lenses 221, 222, 223, and 224 change with changes in the temperature environment. Therefore, when the temperature characteristics of the head housing 10 and the temperature characteristics of the plurality of lenses 221, 222, 223, and 224 are known in advance, it becomes possible to design the measurement heads 1A and 1B based on the known information so that a desired measurement error occurs with changes in the temperature environment.

[0128] Therefore, for example, when measuring the thickness of the measurement object S in Figure 4, if the holding positions of the measuring heads 1A, 1B by the frame body 900 and the mounting fixtures 400, 500 change with changes in the temperature environment, it is preferable that the measuring heads 1A, 1B are configured so that the measurement error generated by the change in the holding positions is offset.

[0129] That is, the head housing 10 and the optical system (221-224) of the measurement heads 1A and 1B are preferably designed so that the measurement error caused by their temperature characteristics cancels out the measurement error caused by the temperature characteristics of the frame 900 and the mounting fixtures 400, 500 used in the thickness measurement. In this case, even if the temperature environment changes when the thickness of the measurement object S is measured, the thickness of the measurement object S can be measured with high accuracy without requiring correction processing that takes into account the change in the temperature environment.

[0130] 6. Matching communication function The confocal displacement meter 9 according to this embodiment has a coincidence communication function. The coincidence communication function includes determining the degree of coincidence, which indicates the degree to which the optical axes of the two measuring heads 1A, 1B used to measure the thickness of the measurement target S coincide, in response to an operation of the operating unit 4b by the user or a request from an external device. The coincidence communication function also includes transmitting the determination result of the coincidence to a predetermined external device.

[0131] In this case, the user can display the result of the coincidence determination received by, for example, an external device on a display device other than the main display unit 4a and the sub-display unit 190. Examples of the external device include a PLC (programmable logic controller), a control panel, or a tablet terminal that can be carried by the user. This allows the user to place the other display device near the measuring heads 1A and 1B and adjust the position of the optical axis LA of the measuring head 1A relative to the measuring head 1B while visually checking the coincidence displayed on the display device.

[0132] A matching degree communication program corresponding to the matching degree communication function is stored in the memory 3b in Fig. 1. The CPU 3a in Fig. 1 executes the matching degree communication program stored in the memory 3b to realize a plurality of functional units for the matching degree communication function.

[0133] Fig. 18 is a block diagram showing a functional configuration realized in PC3 by executing the coincidence communication program. As shown in Fig. 18, PC3 includes a command receiving unit fb1, a coincidence determination unit fb2, and an information communication unit fb3 as functional units corresponding to the coincidence communication function. Note that some or all of these functional units may be configured by hardware such as electronic circuits.

[0134] The command reception unit fb1 receives a command signal to use the coincidence communication function. This command signal is given to the command reception unit fb1 by a user operating the operation unit 4b. Alternatively, the command signal is given to the command reception unit fb1 from an external device 600 of the confocal displacement meter 9.

[0135] When the command receiving unit fb1 receives a command signal to use the coincidence communication function, it provides the control unit 2 with measurement conditions for determining the coincidence between the optical axes of the two measuring heads 1A and 1B. In this case, the control unit 2 provides the provided measurement conditions to the measurement control units 150 (FIG. 1) of the measuring units 100A and 100B.

[0136] As a result, the confocal displacement meter 9 transitions to a state in which, for example, light is emitted from one measuring head 1A (or measuring head 1B) and light is not emitted from the other measuring head 1B (or measuring head 1A). In this case, if the degree of coincidence of the optical axes is high, the intensity of the light emitted from the measuring head 1A (or measuring head 1B) and incident on the measuring unit 100B (or measuring unit 100A) through the measuring head 1B (or measuring head 1A) increases. Therefore, a light receiving signal output from the measuring unit 100B (or measuring unit 100A) is provided to the control unit 2. The control unit 2 provides the provided light receiving signal to the PC3.

[0137] In the PC3, the coincidence determination section fb2 determines the coincidence between the optical axes of the measurement heads 1A and 1B based on the light receiving signal provided from the control unit 2. The information communication section fb3 transmits the coincidence determination result to a predetermined external device 600. The destination of the coincidence determination result may be provided to the command reception section fb1 as accompanying information of the command signal when a command signal to use the coincidence communication function is provided to the command reception section fb1. In this case, the information communication section fb3 transmits the coincidence determination result only to the external device 600 designated as the destination based on the accompanying information provided to the command reception section fb1.

[0138] Fig. 19 is a flowchart of the coincidence communication process based on the coincidence communication program. The coincidence communication process is repeated at a predetermined cycle, for example, while the power supply of the confocal displacement meter 9 is on. As shown in Fig. 19, first, the command reception unit fb1 in Fig. 18 judges whether or not a command signal to use the coincidence communication function is received by the user's operation of the operation unit 4b or communication from the external device 600 (step S101). If the command signal is not received, the command reception unit fb1 repeats the process of step S101. On the other hand, when a command signal is received, the command reception unit fb1 provides the control unit 2 with measurement conditions for determining the coincidence degree of the optical axis (step S102).

[0139] Next, the coincidence determination unit fb2 determines whether or not a light reception signal is provided from one of the measurement units 100A and 100B (step S103). If a light reception signal is not provided, the coincidence determination unit fb2 repeats the process of step S103. On the other hand, if a light reception signal is provided, the coincidence determination unit fb2 determines the coincidence based on the light reception signal (step S104). The coincidence determination may be performed based on whether the intensity of the provided light reception signal exceeds a predetermined threshold value, or based on which of a plurality of intensity ranges that are previously divided into levels the intensity of the provided light reception signal belongs to. Thereafter, the information communication unit fb3 transmits the determination result of the coincidence to a predetermined external device 600 (step S105). This ends the coincidence communication process.

[0140] According to the above-mentioned coincidence communication function, the user can align the optical axes between the two measuring heads 1A and 1B while displaying on the display device the coincidence determination result transmitted to the external device 600. This makes it possible to align the optical axes with high accuracy while improving work efficiency.

[0141] The above-mentioned coincidence communication function also enables the following operation. For example, assume a case where multiple sheet-like measurement objects S are intermittently measured. Specifically, one measurement object S is placed between the measurement heads 1A and 1B, and after the thickness is measured, the measurement object S is removed from between the measurement heads 1A and 1B. Thereafter, the next measurement object S is placed between the measurement heads 1A and 1B, and the thickness is measured.

[0142] When such an operation is repeated, there are times when the measurement object S is not present between the measurement heads 1A and 1B. Therefore, the coincidence communication function is used at times when the measurement object S is not present between the measurement heads 1A and 1B. In this case, the coincidence is transmitted to the external device 600 every time the thickness of the measurement object S is measured. Therefore, the user can check the misalignment of the optical axes between the measurement heads 1A and 1B every time the thickness of the measurement object S is measured by displaying the transmitted coincidence on a desired display device.

[0143] 7.Effects (a) The mounting fixture 400 according to this embodiment can be arranged in a predetermined arrangement direction (Y direction in the above example) together with a plurality of other mounting fixtures 400 having the same configuration as the mounting fixture 400. Here, the directions (first adjustment direction D1 and second adjustment direction D2) for adjusting the position of the optical axis LA of the measuring head 1A attached to the frame 900 using the mounting fixture 400 intersect with the arrangement direction and do not coincide with the arrangement direction.

[0144] Therefore, when a user wants to adjust the position of the optical axis LA of the measuring head 1A for each of the arranged multiple mounting fixtures 400, the user does not need to access the mounting fixture 400 along the arrangement direction. Therefore, there is no need to provide a working space between the multiple mounting fixtures 400 in the arrangement direction for the user to adjust the position of the optical axis LA of the measuring head 1A. As a result, it is possible to arrange the multiple optical axes LA of the multiple measuring heads 1A with higher density while enabling the position adjustment of the optical axis LA for each of the multiple measuring heads 1A.

[0145] (b) In the above mounting tool 400, two screw holes shc for screwing two adjustment screws s2 are formed in the first side surface forming portion 451 of the plate-shaped portion 441. Meanwhile, two spring accommodating portions sf for accommodating two springs sp are formed in the second side surface forming portion 452 of the plate-shaped portion 441. That is, in the mounting tool 400, two adjustment screws s2 are provided in one side surface portion formed by the first side surface forming portion 451. Therefore, in the mounting tool 400, the two adjustment screws s2 can be operated from a position in the direction in which the one side surface portion formed by the first side surface forming portion 451 faces (a position in the +Y direction in the example of FIG. 4).

[0146] (c) In the mounting fixture 400, the head holding portion 460 in the released state is biased toward the first wall portion w1 by a spring sp provided on the second wall portion w2. In this state, when adjusting the position of the optical axis LA, for example, an adjustment screw s2 is screwed in through a screw hole shc formed in the first wall portion w1. As a result, the head holding portion 460 is pressed by the tip of the screwed-in adjustment screw s2, and moves in the first adjustment direction D1 against the biasing force of the spring sp of the second wall portion w2.

[0147] Moreover, the head holding portion 460 in the released state is biased toward the third wall portion w3 by a spring sp provided on the fourth wall portion w4. In this state, when adjusting the position of the optical axis LA, for example, an adjustment screw s2 is screwed in through a screw hole shc formed in the third wall portion w3. As a result, the head holding portion 460 is pressed by the tip of the screwed-in adjustment screw s2, and moves in the second adjustment direction D2 against the biasing force of the spring sp of the fourth wall portion w4.

[0148] As described above, the biasing force of the two springs sp provided on the second wall portion w2 and the fourth wall portion w4 always acts on the head holding portion 460 in the released state. This facilitates the positioning operation of the optical axis LA when adjusting the position of the optical axis LA of the measuring head 1A.

[0149] (d) As described above, the tube portion 461 of the head holding portion 460 has the first tube portion 462 and the second tube portion 463, and a notch cc extending a predetermined distance in the circumferential direction is formed between the first tube portion 462 and the second tube portion 463. With this configuration, when the measurement head 1A is fastened by the first tube portion 462, even if a distortion caused by the fastening occurs in the first tube portion 462, the distortion is unlikely to be transmitted to the second tube portion 463 by the notch cc. This prevents the first tube portion 462 from being supported by the base housing 410 in a position deviating from a predetermined position due to a distortion generated in the first tube portion 462.

[0150] (e) First main body 420 of mounting fixture 400 is configured from a single member. First main body 420 has tip surfaces of three protrusions 431p that serve as mounting surfaces to be attached to lower surface 912 of first beam portion 910.

[0151] In this case, since the first main body 420 is composed of a single member, the tip faces of the three protrusions 431p are attached onto the lower face 912 of the first beam 910, so that one face 422 of the first main body 420 has a fixed positional relationship with the lower face 912 of the first beam 910. As a result, the head holding part 460 is held in a fixed positional relationship with respect to the lower face 912 of the first beam 910, improving the accuracy of measurement of the physical quantity by the measuring head 1A.

[0152] 8. Other embodiments (a) In the mounting tool 400 according to the above embodiment, the first wall portion w1 and the third wall portion w3 are each formed with a screw hole shc, and the second wall portion w2 and the fourth wall portion w4 are each formed with a spring housing portion sf, but the present invention is not limited to this. The first wall portion w1 and the fourth wall portion w4 may each be formed with a screw hole shc, and the third wall portion w3 and the fourth wall portion w4 may each be formed with a spring housing portion sf.

[0153] (b) In the mounting tool 400 according to the above embodiment, a metal spring sp is used to urge the head holding part 460 toward the first wall part w1 and toward the third wall part w3, but the present invention is not limited to this. As a configuration for urging the head holding part 460 toward the first wall part w1 and the third wall part w3, a resin spring may be used instead of the metal spring sp, or another elastic body such as rubber may be used.

[0154] (c) In the above embodiment, only one of the two measurement heads 1A, 1B for measuring the thickness of the measurement object S, the measurement head 1A, is attached to the frame 900 by the mounting fixture 400, and the position of the optical axis LA can be adjusted, but the present invention is not limited to this. Both of the two measurement heads 1A, 1B for measuring the thickness of the measurement object S may be attached to the frame 900 by the mounting fixture 400. In this case, the measurement head 1A is attached to the mounting portion 919 of the first beam portion 910 by the mounting fixture 400, and the measurement head 1B is attached to the mounting portion 929 of the second beam portion 920 by the mounting fixture 400.

[0155] (d) Although the measurement heads 1A and 1B according to the above embodiment are measurement heads for a confocal displacement meter, the present invention is not limited to this. The measurement head attached to the installation surface by the mounting fixture 400 may be a measurement head for a laser displacement meter or a non-contact optical thermometer.

[0156] (e) The frame body 900 according to the above embodiment is composed of a single member, but the present invention is not limited to this. The frame body 900 may have a configuration in which a plurality of members are connected. In this case, it is preferable that the plurality of members constituting the frame body 900 are formed of a common material. Furthermore, the frame body 900 according to the above embodiment has a shape (a square or rectangular shape) composed of the first to fourth sides when the first beam portion 910 is the first side, the second beam portion 920 is the second side, and the two pillar portions 930 are the third and fourth sides, respectively, but the present invention is not limited to this. The frame body 900 may have a shape (a square or U-shape) composed of the first beam portion 910, the second beam portion 920, and one pillar portion 930.

[0157] (f) In the above embodiment, the multiple mounting fixtures 400 attached to the first beam portion 910 of the frame body 900 are lined up in the Y direction with the first side surface forming portion 451 of each mounting fixture 400 facing the +Y direction and the second side surface forming portion 452 facing the -Y direction, but the present invention is not limited to this. The multiple mounting fixtures 400 may be lined up in the Y direction with at least some of the multiple mounting fixtures 400 having the first side surface forming portion 451 facing the -Y direction and the second side surface forming portion 452 facing the +Y direction.

[0158] 9. Correspondence between each component of the claims and each part of the embodiment Below, examples of the correspondence between each component of the claims and each part of the embodiment will be described, but the present invention is not limited to the following examples. Various other elements having the configuration or function described in the claims can also be used as each component of the claims.

[0159] In the above embodiment, the optical axis LA is an example of an optical axis, the measurement heads 1A and 1B are examples of measurement heads, the lower surface 912 of the frame body 900 is an example of an installation surface, the mounting fixture 400 is an example of a mounting fixture, the head holding portion 460 is an example of a head holding portion, one surface 422 of the first main body portion 420 of the base housing 410 is an example of one surface and a support surface, and the base housing 410 is an example of a base housing.

[0160] Also, the posture of mounting fixture 400 when first side surface forming portion 451 and second side surface forming portion 452 are arranged side by side along the Y direction on lower surface 912 of first beam portion 910 is an example of a common posture.

[0161] In addition, the first adjustment direction D1 is an example of a first adjustment direction, the second adjustment direction D2 is an example of a second adjustment direction, the two adjustment screws s2 are examples of a first adjustment screw and a second adjustment screw, the fixing screw s1 is an example of a switching portion and a fixing screw, and the Y direction in which the first beam portion 910 of the frame body 900 extends is an example of an arrangement direction.

[0162] In addition, the side formed by the first side forming portion 451 is an example of a first side, the side formed by the second side forming portion 452 is an example of a second side, the first wall portion w1 is an example of a first wall portion, the second wall portion w2 is an example of a second wall portion, the third wall portion w3 is an example of a third wall portion, and the fourth wall portion w4 is an example of a fourth wall portion.

[0163] In addition, the screw hole shc formed in the first wall portion w1 is an example of a first screw hole, the spring sp provided in the second wall portion w2 is an example of a first elastic body, the screw hole shc formed in the third wall portion w3 is an example of a second screw hole, and the spring sp provided in the fourth wall portion w4 is an example of a second elastic body.

[0164] In addition, the end face formed by the second end face forming portion 432 is an example of a first end face, the other face formed by the first end face forming portion 431 is an example of a second end face, through hole 432h is an example of a first screw passage, through hole 431h is an example of a second screw passage, first main body portion 420 is an example of a first main body portion, screw hole 425 is an example of a fixing screw hole, and through hole 465 is an example of a through hole formed in the head holding portion.

[0165] In addition, second main body portion 440 is an example of a second main body portion, rotational force blocking member 480 is an example of a rotational force blocking member, the tip surfaces of protrusions 431p, 432p are examples of mounting surfaces, tubular portion 461 is an example of a tubular portion, supported portions 464a to 464d are examples of supported portions, one end portion 461a is an example of a first end portion, the other end portion 461b is an example of a second end portion, first tubular portion 462 is an example of a first tubular portion, and second tubular portion 463 is an example of a second tubular portion.

[0166] Moreover, the notch cc is an example of a notch, the measurement head 1A is an example of a first measurement head, the measurement head 1B is an example of a second measurement head, the first beam 910 is an example of a first beam, the second beam 920 is an example of a second beam, the pillar 930 is an example of a pillar, the frame 900 is an example of a frame, the lenses 221 to 224 are examples of an optical system, and the head housing 10 is an example of an optical system holding section. Furthermore, the coincidence determination section fb2 is an example of a coincidence determination section, the information communication section fb3 is an example of an information communication section, the external device 600 is an example of an external device, and the confocal displacement meter 9 is an example of a displacement meter device.

[0167] 10. Summary of the embodiment (1) The fixtures pertaining to paragraph 1 are A mounting tool for mounting a measurement head having an optical axis extending in one direction and configured to acquire a physical quantity related to a measurement object arranged on the optical axis on an installation surface, comprising: a head holder for holding the measuring head; a base housing configured to be mountable on the installation surface and supporting the head holding unit movably on one surface perpendicular to the optical axis of the measurement head held by the head holding unit; a first adjustment screw that moves the head holding portion supported by the base housing in a first adjustment direction on the one surface; a second adjustment screw that moves the head holding portion supported by the base housing in a second adjustment direction different from the first adjustment direction on the one surface; a switching unit that switches a state of the head holding unit supported by the base housing between a fixed state in which the head holding unit cannot move on the one surface and a released state in which the head holding unit can move on the one surface, The base housing is configured so that a plurality of base housings including the base housing can be arranged in a common posture on the installation surface in a predetermined arrangement direction, The first adjustment direction and the second adjustment direction each intersect with the arrangement direction when the multiple base housings are lined up in the arrangement direction in a common attitude on the installation surface.

[0168] In the mounting fixture, the base housing can be arranged in a predetermined arrangement direction with a common attitude on the installation surface for a plurality of base housings including the base housing. That is, the mounting fixture can be arranged in the arrangement direction together with a plurality of other mounting fixtures having the same configuration as the mounting fixture. Here, each of the first adjustment direction and the second adjustment direction intersects with the arrangement direction and does not coincide with the arrangement direction.

[0169] In this case, when a user wants to adjust the position of the optical axis of the measurement head for each of the multiple fixtures, the user does not need to access the fixture along the arrangement direction. Therefore, there is no need to provide a working space between the multiple fixtures in the arrangement direction for the user to adjust the position of the optical axis of the measurement head. As a result, it is possible to arrange the multiple optical axes of the multiple measurement heads with higher density while enabling the position adjustment of the optical axis for each of the multiple measurement heads.

[0170] (2) In the mounting device according to the first aspect, The base housing may have a first side and a second side that face opposite each other in the arrangement direction when mounted on the installation surface, and may be configured so that the first adjustment screw can be screwed in the first adjustment direction and the second adjustment screw can be screwed in the second adjustment direction from either one of the first side or the second side.

[0171] In this case, the first adjustment screw and the second adjustment screw can be screwed into the base housing from a position in the direction in which one of the first side surface and the second side surface of the base housing faces.

[0172] (3) In the mounting device according to the first or second paragraph, The base housing includes: a first wall portion and a second wall portion that face each other with the head holding portion therebetween in the first adjustment direction in a state in which the head holding portion is supported by the base housing; a third wall portion and a fourth wall portion that face each other with the head holding portion therebetween in the second adjustment direction when the head holding portion is supported by the base housing, a first screw hole extending in the first adjustment direction and into which the first adjustment screw can be screwed is formed in the first wall portion; a first elastic body that biases the head holding portion toward the first wall portion is provided on the second wall portion; a second screw hole extending in the second adjustment direction and into which the second adjustment screw can be screwed is formed in the third wall portion; The fourth wall portion may be provided with a second elastic body that urges the head holding portion toward the third wall portion.

[0173] In this case, the head holding portion in the released state is biased from the second wall portion toward the first wall portion by the first elastic body. In this state, when the first adjustment screw is screwed into the first screw hole, the tip of the first adjustment screw presses the base main body portion and moves in the first adjustment direction against the biasing force of the first elastic body.

[0174] In addition, the head holding portion in the released state is biased from the fourth wall portion toward the third wall portion by the second elastic body. In this state, when the second adjustment screw is screwed into the second screw hole, the tip of the second adjustment screw presses the base main body portion and moves in the second adjustment direction against the biasing force of the second elastic body.

[0175] As described above, the biasing forces of the first elastic body and the second elastic body are always applied to the base main body in the released state, which makes it easier to position the optical axis when adjusting the position of the optical axis of the measurement head.

[0176] (4) In the mounting device according to the third aspect, the base housing has a first end surface and a second end surface facing in opposite directions to each other in a direction perpendicular to the arrangement direction when viewed from a position facing the installation surface in a state where the base housing is attached to the installation surface; The base housing may be formed with a first screw passage extending from the first end face toward the first wall portion of the base housing adjacent to the base housing when the multiple base housings are arranged closely in the arrangement direction in a common posture on the installation surface, and a second screw passage extending from the second end face toward the third wall portion of the base housing adjacent to the base housing.

[0177] According to the above configuration, when it is desired to adjust the position of the optical axis of the measurement head for each of a plurality of fixtures arranged closely together in the arrangement direction, the first adjustment screw can be operated through the first screw passage of the fixture adjacent to the fixture in question, and the second adjustment screw can be operated through the second screw passage of the fixture adjacent to the fixture in question.

[0178] (5) In the mounting device according to any one of the first to fourth aspects, the base housing includes a first main body portion having a flat support surface constituting the one surface and configured to be able to support the head holding portion on the support surface; The support surface is formed with a fixing screw hole that opens toward a space above the support surface, a through hole having an inner diameter larger than that of the fixing screw hole is formed in the head holding portion; The switching portion may include a fixing screw that is screwed into the fixing screw hole through the through hole with the head holding portion supported on the support surface.

[0179] According to the above configuration, the head holding portion is fixed by tightening the fixing screw. On the other hand, the head holding portion is released by loosening the degree of tightening of the fixing screw. In this way, the state of the head holding portion can be easily changed by operating the fixing screw.

[0180] (6) In the mounting device according to the above (5), the base housing includes a second main body portion attached to the support surface of the first main body portion in a predetermined positional relationship with at least a portion of the head holding portion therebetween; The mounting fixture includes: The fixing screw is further provided with a rotational force blocking member provided between a head of the fixing screw and the head holding portion in a state in which the fixing screw is screwed into the fixing screw hole of the first body portion through the through hole of the head holding portion, The rotational force blocking member may be configured to be unable to rotate around the axis of the fixing screw by contacting the second body portion.

[0181] According to the above configuration, because the rotational force blocking member cannot rotate around the axis of the fixing screw, the rotational force generated in the head of the fixing screw when the fixing screw is tightened is not transmitted to the rotational force blocking member. As a result, when the head holding part is changed from the released state to the fixed state, the rotational force of the fixing screw does not act on the head holding part. Therefore, when the fixing screw is tightened, the head holding part is prevented from shifting in an unintended direction relative to the first main body part.

[0182] (7) In the mounting device according to the 5th or 6th paragraph, The first main body portion may be formed from a single member and have a mounting surface that is attached to the installation surface.

[0183] In this case, since the first main body is made of a single member, the mounting surface is attached to the installation surface, so that the support surface has a fixed positional relationship with the installation surface. This allows the head holding part to be held in a fixed positional relationship with respect to the installation surface, improving the accuracy of the measurement of the physical quantity by the measurement head.

[0184] (Item 8) In the mounting device according to any one of items 1 to 7, The measurement head has a cylindrical shape extending along the optical axis, The head holding portion is A cylindrical portion into which the measuring head can be inserted; a supported portion supported by the base housing, the tubular portion has a first end and a second end, and has a first tubular portion and a second tubular portion aligned in sequence from the first end to the second end, A notch is formed between the first and second cylindrical portions of the cylindrical portion, the notch extending a certain distance in a circumferential direction of the cylindrical portion, the first cylindrical portion is configured to be able to hold the measuring head by tightening an outer periphery of the measuring head in a state in which the measuring head is inserted, The supported portion may be provided on an outer periphery of the second cylindrical portion so that the head holding portion is supported by the base housing in a predetermined attitude.

[0185] In this case, when the measuring head is inserted into the cylindrical portion, the first cylindrical portion tightens the outer periphery of the measuring head, thereby holding the measuring head in the head holding portion. In this state, distortion may occur in the first cylindrical portion of the cylindrical portion due to tightening the outer periphery of the measuring head.

[0186] Even in such a case, according to the above configuration, since the notch is formed between the first and second cylindrical portions of the cylindrical portion, the distortion occurring in the first cylindrical portion is unlikely to be transmitted to the second cylindrical portion, and thus the head holding portion is prevented from being supported by the base housing in a position deviating from a predetermined position due to the distortion occurring in the first cylindrical portion.

[0187] (Item 9) In the mounting device according to any one of items 1 to 8, The head holding portion, the base housing, the first adjusting screw, the second adjusting screw and the switching portion may be formed from a common metallic material.

[0188] In this case, since each component of the fixture is formed from a common metal material, it is easy to grasp changes in the holding state of the measuring head that accompany changes in the temperature environment.

[0189] (Item 10) In the mounting device according to any one of items 1 to 9, The measuring head includes: a displacement meter that acquires a distance from the measurement head to the measurement object disposed on the optical axis as the physical quantity, The two measuring heads are arranged as a first measuring head and a second measuring head facing each other on one axis with a measurement object therebetween, thereby making it possible to measure the thickness of the measurement object, In order to measure the thickness of the measurement object, a frame is used that has a first beam portion to which the first measurement head is attached, a second beam portion to which the second measurement head is attached, and a column portion that connects the first beam portion and the second beam portion, The mounting fixture is used for at least one of attaching the first measurement head to the mounting surface of the first beam portion and attaching the second measurement head to the mounting surface of the second beam portion, and may be formed from the same material as the frame body.

[0190] According to the above configuration, the fixture for attaching at least one of the first measuring head and the second measuring head to the frame is made of the same material as the frame. This makes it easy to grasp the change in the distance between the first measuring head and the second measuring head due to the change in the temperature environment. Therefore, when measuring the thickness of the measurement object, it becomes easy to perform calculation processing such as correction due to the change in the temperature environment.

[0191] (11) The measuring head according to the 11th paragraph is A measurement head that is attached to the mounting fixture described in claim 10 as the first measurement head or the second measurement head and has an optical system holding part that holds an optical system corresponding to the optical axis, The optical system and the optical system holding part are configured so that when the temperature environment changes when measuring the thickness of the object to be measured using the frame body, and the holding position of the measurement head by the frame body and the mounting fixture changes on the optical axis, errors in the measurement result of the thickness of the object to be measured that would occur due to changes in the holding position of the measurement head are offset.

[0192] According to the above configuration, even if the temperature environment changes, it is possible to measure the thickness of the measurement object with high accuracy without requiring correction processing or the like that takes into account the change in the temperature environment.

[0193] (12) The displacement gauge device according to the 12th paragraph is A first measuring head according to claim 10; A second measuring head according to claim 10; a coincidence determination unit that determines a degree of coincidence indicating the degree to which an optical axis of the first measurement head and an optical axis of the second measurement head coincide with each other based on an intensity of light emitted from one of the first measurement head and the second measurement head and incident on the other measurement head while the first measurement head and the second measurement head are disposed opposite each other; The information communication unit transmits a result of the coincidence determination unit to a predetermined external device.

[0194] In this case, the user can display the result of the coincidence judgment transmitted to the external device on the display device. Therefore, in the preparation stage for measuring the thickness of the measurement object using the first measurement head and the second measurement head, the user can align the optical axes between the first measurement head and the second measurement head while visually checking the result of the coincidence judgment. As a result, the efficiency of the optical axis alignment work is improved. Also, the optical axis can be aligned with high accuracy. [Explanation of symbols]

[0195] 1A, 1B... measurement head, 2... control unit, 3a... CPU, 3b... memory, 4a... main display unit, 4b... operation unit, 9... confocal displacement meter, 10... head housing, 30... fiber receptacle, 100A, 100B... measurement unit, 110... unit housing, 120... light-emitting unit, 130... spectroscopic unit, 131... diffraction grating, 132, 133, 221, 222, 223, 224... lenses, 140... light-receiving unit, 150... measurement control unit, 190... sub-display unit, 300A, 300B... light-guiding unit, 311, 312, 319... optical fiber, 320... fiber coupler, 321, 322, 323... port ,324...main body,330...fiber connector,400...mounting fixture,400A...first mounting fixture,400B...second mounting fixture,410...base housing,420...first main body,421,441...plate-shaped part,422,442...one side,423,443...other side,424...head opening,425,sha,shb,shc...screw hole,431...first end face forming part,431h,432h,445,465,481h,913,914,923,924...through hole,431p,432p...projection part,432...second end face forming part,440...second main body,444...holding part opening,446a,44 6b...notch, 451...first side forming portion, 452...second side forming portion, 460...head holding portion, 461...tubular portion, 461a...one end portion, 461b...other end portion, 462...first tubular portion, 462b...fastening portion, 463...second tubular portion, 464a, 464b, 464c, 464d...supported portion, 480...rotational force blocking member, 481...screw receiving portion, 482...connecting portion, 500...mounting fixture, 510...base portion, 511...support surface, 511a...first support surface, 511b...second support surface, 512...step portion, 513...supported surface, 515...mounting portion, 519...head opening, 519s...head contact surface , 550 ... holding piece, 550s ... concave surface, 600 ... external device, 900 ... frame body, 910 ... first beam part, 911, 921 ... upper surface, 912, 922 ... lower surface, 919, 929 ... mounting part, 920 ... second beam part, 930 ... column part, 950 ... frame body support member, AA1, AA2 ... arrow, AR1, AR2 ... area, D1 ... first adjustment direction, D2 ... second adjustment direction, FE ... tip part, LA ... optical axis, RB1, RB2 ... ring-shaped member, S ... measurement object, VS ... horizontal virtual surface, cc ... notch, fb1 ... command reception unit, fb2 ... coincidence determination unit, fb3 ... information communication unit, nh ... through hole, r1, r2 ... member,s1...fixing screw, s2...adjusting screw, s3, s4, s5, s10...screw, sf...spring housing, sp...spring, w1...first wall, w2...second wall, w3...third wall, w4...fourth wall,

Claims

1. A mounting tool for mounting a measurement head having an optical axis extending in one direction and configured to acquire a physical quantity related to a measurement object arranged on the optical axis on an installation surface, comprising: a head holder for holding the measuring head; a base housing configured to be mountable on the installation surface and supporting the head holding unit movably on one surface perpendicular to the optical axis of the measurement head held by the head holding unit; a first adjustment screw that moves the head holding portion supported by the base housing in a first adjustment direction on the one surface; a second adjustment screw that moves the head holding portion supported by the base housing in a second adjustment direction different from the first adjustment direction on the one surface; a switching unit that switches a state of the head holding unit supported by the base housing between a fixed state in which the head holding unit cannot move on the one surface and a released state in which the head holding unit can move on the one surface, The base housing is configured so that a plurality of base housings including the base housing can be arranged in a common posture on the installation surface in a predetermined arrangement direction, A mounting fixture in which the first adjustment direction and the second adjustment direction each intersect with the arrangement direction when the multiple base housings are lined up in the arrangement direction in a common attitude on the installation surface.

2. 2. The mounting fixture of claim 1, wherein the base housing, when attached to the installation surface, has a first side and a second side that face in opposite directions in the arrangement direction when viewed from a position facing the installation surface, and is configured so that the first adjustment screw can be screwed in the first adjustment direction and the second adjustment screw can be screwed in the second adjustment direction from either one of the first side and the second side.

3. The base housing includes: a first wall portion and a second wall portion that face each other with the head holding portion therebetween in the first adjustment direction in a state in which the head holding portion is supported by the base housing; a third wall portion and a fourth wall portion that face each other with the head holding portion therebetween in the second adjustment direction when the head holding portion is supported by the base housing, a first screw hole extending in the first adjustment direction and into which the first adjustment screw can be screwed is formed in the first wall portion; a first elastic body that biases the head holding portion toward the first wall portion is provided on the second wall portion; a second screw hole extending in the second adjustment direction and into which the second adjustment screw can be screwed is formed in the third wall portion; 3. The fixture according to claim 1, wherein the fourth wall portion is provided with a second elastic body that biases the head holding portion toward the third wall portion.

4. the base housing has a first end surface and a second end surface facing in opposite directions to each other in a direction perpendicular to the arrangement direction when viewed from a position facing the installation surface in a state where the base housing is attached to the installation surface; 4. The mounting fixture of claim 3, wherein the base housing is formed with a first screw passage extending from the first end face toward the first wall portion of the base housing adjacent to the base housing when the multiple base housings are lined up closely in the arrangement direction in a common posture on the installation surface, and a second screw passage extending from the second end face toward the third wall portion of the base housing adjacent to the base housing.

5. the base housing includes a first main body portion having a flat support surface constituting the one surface and configured to be able to support the head holding portion on the support surface; The support surface is formed with a fixing screw hole that opens toward a space above the support surface, The head holding portion is formed with a through hole having an inner diameter larger than that of the fixing screw hole, The fixture according to claim 1 or 2, wherein the switching portion includes a fixing screw that is screwed into the fixing screw hole through the through hole with the head holding portion supported on the support surface.

6. the base housing includes a second main body portion attached to the support surface of the first main body portion in a predetermined positional relationship with at least a portion of the head holding portion therebetween, The mounting fixture includes: The fixing screw further includes a rotational force blocking member provided between a head of the fixing screw and the head holding portion when the fixing screw is screwed into the fixing screw hole of the first body portion through the through hole of the head holding portion, The mounting tool according to claim 5 , wherein the rotational force blocking member is configured to be unable to rotate around the axis of the fixing screw by contacting the second body portion.

7. The fixture of claim 5 , wherein the first body portion is constructed from a single member and has a mounting surface adapted to be attached to the installation surface.

8. The measurement head has a cylindrical shape extending along the optical axis, The head holding portion is A cylindrical portion into which the measuring head can be inserted; a supported portion supported by the base housing, the tubular portion has a first end and a second end, and has a first tubular portion and a second tubular portion aligned in sequence from the first end to the second end, A notch is formed between the first and second cylindrical portions of the cylindrical portion, the notch extending a certain distance in a circumferential direction of the cylindrical portion, the first cylindrical portion is configured to be able to hold the measuring head by tightening an outer periphery of the measuring head in a state in which the measuring head is inserted, 3. The fixture according to claim 1, wherein the supported portion is provided on an outer periphery of the second cylindrical portion so that the head holding portion is supported by the base housing in a predetermined attitude.

9. The fixture according to claim 1 or 2, wherein the head holding portion, the base housing, the first adjusting screw, the second adjusting screw and the switching portion are formed from a common metallic material.

10. The measuring head includes: a displacement meter that acquires a distance from the measurement head to the measurement object disposed on the optical axis as the physical quantity, The two measuring heads are arranged as a first measuring head and a second measuring head facing each other on one axis with a measurement object therebetween, thereby making it possible to measure the thickness of the measurement object, In order to measure the thickness of the measurement object, a frame is used that has a first beam portion to which the first measurement head is attached, a second beam portion to which the second measurement head is attached, and a column portion that connects the first beam portion and the second beam portion, The fixture according to claim 1 or 2, which is used for at least one of attaching the first measurement head to the installation surface of the first beam portion and attaching the second measurement head to the installation surface of the second beam portion, and is formed from the same material as the frame body.

11. A measurement head that is attached to the fixture according to claim 10 as the first measurement head or the second measurement head and has an optical system holding part that holds an optical system corresponding to the optical axis, A measurement head, wherein the optical system and the optical system holding part are configured so that when the holding position of the measurement head by the frame body and the mounting fixture changes on the optical axis as the temperature environment changes when measuring the thickness of the measurement object using the frame body, errors in the measurement results of the thickness of the measurement object that would occur due to changes in the holding position of the measurement head are offset.

12. A first measuring head according to claim 10; A second measuring head according to claim 10; a coincidence determination unit that determines a degree of coincidence indicating the degree to which an optical axis of the first measurement head and an optical axis of the second measurement head coincide with each other based on an intensity of light emitted from one of the first measurement head and the second measurement head and incident on the other measurement head while the first measurement head and the second measurement head are disposed opposite each other; and an information communication unit configured to transmit a result of the coincidence determination unit to a predetermined external device.

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