Measurement device

Abstract

The invention provides a measuring device. A measurement device (1) is provided with: a holding unit (31) for holding an object (W) to be measured; a measurement unit (5) (a first measurement unit (51), a second measurement unit (52)) provided at a position facing the holding unit (31) and provided with sensors (511, 521) for performing measurement processing on the object to be measured (W); a frame main body (4) fixed to the position of the holding part (31); and a plurality of arms (6) that connect the frame main body (4) and the measuring unit (5).

Description

Technical Field

[0001] The present invention relates to a measuring device for measuring the shape of an object to be measured. Background Art

[0002] Conventionally, as a measuring device for measuring the shape of an object to be measured, there is known a measuring device in which a measuring sensor is held on a frame (see, for example, Document 1: Japanese Patent Application Publication No. 2016-70691).

[0003] The measuring device described in Document 1 is provided with a first distance sensor supported by a support portion on the upper side of a movable table for placing the object to be measured. In addition, a second distance sensor supported by a support portion is provided on the lower side of the movable table. In this measuring device, the thickness of the object to be measured is calculated based on the distance to the upper surface of the object to be measured measured by the first distance sensor and the distance to the lower surface of the object to be measured measured by the second distance sensor, thereby obtaining the shape of the object to be measured.

[0004] In the measuring device described in Document 1, the measuring sensors (the first distance sensor and the second distance sensor) are fixed to the frame-shaped support portion. However, there are cases where the measuring sensors need to be maintained relative to the stage due to the installation environment of the measuring device, etc. In the measuring device described in Document 1, the measuring sensors are directly fixed to the support portion, so there is a problem that it is difficult to perform such maintenance.

[0005] In particular, in the manufacture of wafers such as WLO (wafer level optics) mounted on small devices such as mobile phones, it is necessary to accurately measure the surface and back of the wafer to be measured. In this case, in order to simultaneously measure the shape of the surface and the shape of the back at a predetermined position of the wafer, it is necessary to accurately align the measurement sensor for the surface and the measurement sensor for the back. In this case, for a structure such as document 1 in which two measurement sensors (a first distance sensor and a second distance sensor) are fixed to a frame-shaped support portion, the interval between the frame and the measurement sensor becomes narrower, making it more difficult to contact the measurement sensor. Summary of the invention

[0006] An object of the present invention is to provide a measuring device that is easy to maintain, such as adjusting the position of a measuring sensor for measuring an object to be measured.

[0007] A first form of a measuring device disclosed herein comprises: a holding portion for holding an object to be measured; a measuring portion, which is arranged at a position opposite to the holding portion and has a sensor for performing a measurement process on the object to be measured; a frame body; and a plurality of arms connecting the frame body and the measuring portion.

[0008] Thus, when the position and posture of the measuring unit relative to the frame body of the measuring device need to be finely adjusted, the position and posture of the measuring unit can be easily adjusted by finely adjusting the angle and length of the arm. In addition, by installing the arm so that the frame body and the measuring unit are arranged separately, it becomes easy to access the measuring unit through the gap between the frame body and the measuring unit, and maintenance can be easily performed.

[0009] In the measuring device of this form, it is preferred that the direction from the measuring part toward the object to be measured is set as the Z direction, the direction orthogonal to the Z direction is set as the X direction, the direction orthogonal to the X direction and the Z direction and from the frame body toward the measuring part is set as the Y direction, and the multiple arms include a plurality of Z support arms arranged along the Z direction and a plurality of X support arms arranged along the X direction.

[0010] Thus, the Z support arm and the X support arm can suppress changes in the posture of the measurement unit.

[0011] In the measuring device of this form, it is preferred that the measuring part comprises: a first measuring part, which is arranged at a position opposite to a first surface of the measured object held by the holding part; and a second measuring part, which is arranged at a position opposite to a second surface of the measured object held by the holding part on the opposite side of the first surface, and the first measuring part and the second measuring part are respectively connected to the frame body using a plurality of the arms.

[0012] Thus, the surface shape of the first surface and the surface shape of the second surface of the object to be measured can be measured simultaneously.

[0013] In the measuring device of this form, preferably, the plurality of Z support arms include a plurality of first Z support arms supporting the first measuring part and a plurality of second Z support arms supporting the second measuring part, and in the projection view observed from the X direction, the plurality of first Z support arms and the plurality of second Z support arms are respectively arranged at positions symmetrical with respect to a reference line, the reference line includes a midpoint between the first measuring part and the second measuring part and is parallel to the Y direction, a fixed position of the first Z support arm relative to the frame body and a fixed position of the second Z support arm symmetrical with the first Z support arm with respect to the reference line relative to the frame body are arranged on a first imaginary line parallel to the Z direction, and a fixed position of the first Z support arm relative to the first measuring part and a fixed position of the second Z support arm symmetrical with the first Z support arm with respect to the reference line relative to the second measuring part are arranged on a second imaginary line parallel to the Z direction.

[0014] Therefore, the first Z support arm and the second Z support arm can absorb dimensional changes such as strain of the frame body caused by temperature changes, thereby suppressing the deviation of the positional relationship between the first measuring part and the second measuring part caused by the dimensional change of the frame body and the resulting measurement error.

[0015] In the measuring device of this aspect, preferably, the plurality of X supporting arms include a plurality of first X supporting arms supporting the first measuring unit and a plurality of second X supporting arms supporting the second measuring unit, the plurality of first X supporting arms and the plurality of second X supporting arms are respectively arranged in positions symmetrical with respect to a reference plane in the Z direction, the reference plane includes a midpoint between the first measuring unit and the second measuring unit and is parallel to an XY plane, the coordinates of the first X supporting arm in the X direction of a fixed position relative to the frame body are the same as the coordinates of the second X supporting arm in the X direction of a fixed position relative to the frame body that is symmetrical with the first X supporting arm with respect to the reference plane, and the coordinates of the first X supporting arm in the X direction of a fixed position relative to the first measuring unit are the same as the coordinates of the second X supporting arm in the X direction of a fixed position relative to the second measuring unit that is symmetrical with the first X supporting arm with respect to the reference plane.

[0016] Thus, as in the above-mentioned embodiment, the first X-support arm and the second X-support arm can be used to absorb dimensional changes such as strain of the frame body caused by temperature changes, thereby suppressing the deviation of the positional relationship between the first measurement part and the second measurement part caused by the dimensional change of the frame body and the generation of measurement errors caused by the deviation.

[0017] In the measuring device of this aspect, it is preferred that each of the plurality of arms is constructed so that the length in the longitudinal direction of the arm can be extended or retracted.

[0018] Thus, by extending and retracting the arm, the position and posture of the measurement unit relative to the frame body can be easily adjusted.

[0019] In the measuring device of this form, the arm comprises: a longitudinally long arm body; and an arm fixing mechanism, which is arranged at least one of the end portions on the frame body side and the end portions on the measuring part side in the longitudinal direction of the arm body, and the arm fixing mechanism comprises: a fixing plate, which is fixed to the frame body or the measuring part; an arm supporting part, which supports the arm body so as to be rotatable; and an adjustment part, which connects the fixing plate and the arm supporting part so that the position of the arm supporting part relative to the fixing plate moves forward and backward along the longitudinal direction of the arm body.

[0020] By operating the adjustment portion, the arm support portion can be advanced and retreated relative to the fixing piece, and the length of the arm in the longitudinal direction can be easily adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view showing a measuring device according to one embodiment of the present invention.

[0022] Figure 2 This is a side view of the measuring device according to this embodiment as viewed from the -X side.

[0023] Figure 3 This is a plan view of the measuring device according to this embodiment as viewed from the +Z side.

[0024] Figure 4A This is a diagram showing an arm fixing mechanism of the arm according to the present embodiment, and is a plan view of a part of the arm arranged on the -X side as seen from the -X side.

[0025] Figure 4B is a diagram showing an arm fixing mechanism of an arm according to the present embodiment, Figure 4A Cross-sectional view at line BB.

[0026] Figure 5 This is a cross-sectional view of a portion of the arm of the present embodiment cut along a plane passing through a middle position in the thickness direction.

[0027] Figure 6 It is a schematic perspective view showing the positional relationship of the X support arms according to the present embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, one embodiment of the present invention will be described.

[0029] Figure 1 It is a perspective view showing the measuring device 1 according to the present embodiment.

[0030] The measuring device 1 of this embodiment is a measuring device for measuring the shape of a WLO (wafer level optical element). Figure 1 As shown, the measuring device 1 includes: a table 3 fixed to a base 2 ; a frame body 4 ; and measuring parts 5 (a first measuring part 51 , a second measuring part 52 ) connected to the frame body 4 via an arm 6 .

[0031] [Structure of workbench 3]

[0032] The workbench 3 is provided with: a holding portion 31 that holds the object to be measured W (WLO in this embodiment); and a moving mechanism 32 that moves the holding portion 31 in the horizontal direction (XY direction). In this embodiment, the shape of the +Z side surface (first surface) of the object to be measured W held by the holding portion 31 is measured by the first measuring portion 51, and the shape of the -Z side surface (second surface) of the object to be measured W is measured by the second measuring portion 52. Therefore, a hole portion penetrating in the Z direction is provided in the holding portion 31, and the object to be measured W held by the holder 311 is placed on the holding portion 31.

[0033] In addition, the moving mechanism 32 includes an X moving mechanism 321 that moves the holding portion 31 in the X direction and a Y moving mechanism 322 that moves the holding portion 31 in the Y direction. The structures of these X moving mechanism 321 and Y moving mechanism 322 are not particularly limited, and any mechanism can be used as long as it is a structure that moves the holding portion 31 in the XY directions. For example, as the X moving mechanism 321, a structure including the following components can be exemplified: an X guide rail that is provided on a support table fixed to the base 2 and parallel to the X direction; an X slide that can move along the X guide rail in the X direction; and an X actuator that moves the X slide in the X direction. As the Y moving mechanism 322, a structure including the following components can be exemplified: a Y guide rail that is provided on the X slide and parallel to the Y direction; a Y slide that can move along the Y guide rail in the Y direction; and a Y actuator that moves the Y slide in the Y direction.

[0034] These moving mechanisms 32 can be controlled by a controller (not shown), and based on the control of the controller, the object W held by the holding unit 31 can be moved along the X direction and the Y direction between the first measuring unit 51 and the second measuring unit 52. Thus, the measurement position of the object W measured by the first measuring unit 51 and the second measuring unit 52 can be moved.

[0035] [Structure of the measuring unit 5]

[0036] The measuring unit 5 includes a first measuring unit 51 and a second measuring unit 52 .

[0037] The first measurement unit 51 is disposed on the +Z side (upper side) of the table 3 , and includes a first measurement sensor 511 and a first plate 512 .

[0038] In this embodiment, the first measuring sensor 511 uses a SIM (Structured Illumination Microscope) sensor suitable for measuring WLO. In such a SIM sensor, it is easy to perform high-precision measurement on the measured object W with low reflectivity (translucent) such as WLO. The measuring axis of the first measuring sensor 511 is parallel to the Z direction, and the measuring direction is toward the -Z side. Therefore, when the measured object W is held on the holding portion 31 of the workbench 3, the first measuring sensor 511 can perform shape measurement of the upper surface (+Z side) of the measured object W.

[0039] The first plate 512 is a fixing plate for fixing the first measuring sensor 511, and is arranged on the -Y side (back side) of the first measuring sensor 511, that is, at a position opposite to the frame body 4. The first plate 512 is connected to the frame body 4 by means of a plurality of arms 6, as will be described later. In addition, the first plate 512 may also be provided integrally with the first measuring sensor 511.

[0040] The second measurement unit 52 is disposed on the −Z side (lower side) of the table 3 , and includes a second measurement sensor 521 and a second plate 522 .

[0041] In this embodiment, the second measuring sensor 521 uses a SIM sensor similar to the first measuring sensor 511. The measuring axis of the second measuring sensor 521 is parallel to the Z direction, and the measuring direction is toward the +Z side. Therefore, the second measuring sensor 521 can perform shape measurement of the lower surface (-Z side) of the object W to be measured while the object W is held by the holding portion 31 of the workbench 3.

[0042] The second plate 522 is a fixing plate for fixing the second measuring sensor 521, and is arranged at the -Y side (back side) of the second measuring sensor 521, that is, at a position opposite to the frame body 4. The second plate 522 is connected to the frame body 4 via a plurality of arms 6, similarly to the first plate 512. In addition, the second plate 522 may be provided integrally with the second measuring sensor 521.

[0043] [Structure of the frame body 4]

[0044] The frame body 4 is fixed to the base 2. The frame body 4 may be fixed directly to the base 2 or may be fixed via other members such as the table 3. The frame body 4 is preferably formed of a strong material such as metal.

[0045] The frame body 4 may house, for example, a controller (not shown) for controlling the operation of the measurement device 1 .

[0046] In addition, the measuring device 1 is provided with a position measuring unit that is opposite to the holding unit 31 of the workbench 3 and measures the position of the holding unit 31. The position measuring unit may be any structure that can measure the position of the holding unit 31 (that is, the position of the object W held by the holding unit 31). For example, in this embodiment, Figure 1 As shown, a laser length measuring device 41 as a position measuring unit is provided in the frame body 4. As the laser length measuring device 41, for example, light from a laser source is branched into reference light and measuring light, and the reference light is irradiated onto a retroreflector (not shown) provided on the holding portion 31. Based on the interference light between the measuring light reflected by the retroreflector and the reference light, the distance from the laser length measuring device to the holding portion 31 provided with the retroreflector is measured. In this way, the position of the holding portion 31 in the Y direction can be measured. In addition, although Figure 1 Although not shown in the figure, the measuring device 1 is further provided with a laser length measuring device for measuring the position of the holding portion in the X direction.

[0047] In addition, the above-mentioned laser length measuring device 41 is an example of a position measuring unit. In addition, it can also be set as the following structure: the position of the holding unit 31 is measured using an encoder set to the driving shaft of the X moving mechanism 321 and the Y moving mechanism 322, or the position of the holding unit 31 is measured using a scale and a detector that detects the scale.

[0048] Furthermore, in this embodiment, a plurality of arms 6 are fixed to the frame body 4, and the measuring unit 5 (the first measuring unit 51 and the second measuring unit 52) ​​is supported by the arms 6. Therefore, the frame body 4 is provided with an arm fixing unit 42 for fixing these arms 6 (see Figure 5 ), a fixing piece 62 constituting the arm 6 is fixed to the arm fixing portion 42.

[0049] [Structure of arm 6]

[0050] (Outline of Arm 6)

[0051] Figure 2 This is a side view of the measuring device 1 according to the present embodiment as viewed from the -X side. Figure 3 This is a plan view of the measuring device 1 according to the present embodiment as viewed from the +Z side.

[0052] In the present embodiment, the arms 6 disposed on the sides (±X side edges) of the first measurement unit 51 and the second measurement unit 52 are Z support arms of the present disclosure. Among these Z support arms, the arms 6 disposed on the sides (±X side edges) of the first measurement unit 51 are first Z support arms 6A1 and 6A2 of the present disclosure. In addition, the arms 6 disposed on the sides of the second measurement unit 52 are second Z support arms 6B1 and 6B2.

[0053] On the other hand, the arms 6 provided above the first measurement unit 51 (+Z side) and below the second measurement unit 52 (-Z side) are X support arms of the present disclosure. Among these X support arms, the arms 6 provided above the first measurement unit 51 are first X support arms 6C1 and 6C2, and the arms 6 provided below the second measurement unit 52 are second X support arms 6D1 and 6D2.

[0054] like Figure 2 As shown, when observing the measuring device 1 from the -X side, of the two first Z support arms 6A1 and 6A2 connected to the -X side of the first plate 512 of the first measuring part 51, the first Z support arm 6A1 on the +Z side is arranged parallel to the Y direction, and the first Z support arm 6A2 on the -Z side is arranged inclined relative to the Y direction (inclined toward the +Z side as it goes toward the +Y side).

[0055] Of the two second Z support arms 6B1 and 6B2 connected to the -X side of the second plate 522 of the second measuring unit 52, the second Z support arm 6B1 on the -Z side is arranged parallel to the Y direction, and the second Z support arm 6B2 on the +Z side is arranged inclined relative to the Y direction (inclined toward the -Z side as it goes toward the +Y side). Figure 3 As shown, the second Z support arms 6B1 and 6B2 connected to the -X side of the second measuring section 52 are arranged at positions closer to the -X side by a predetermined dimension than the two first Z support arms 6A1 and 6A2 connected to the side edges of the -X side of the first measuring section 51. Therefore, the -X side edge of the second plate 522 of the second measuring section 52 protrudes toward the -X side relative to the -X side edge of the first plate 512.

[0056] The first Z support arms 6A1 and 6A2 arranged at the side edge of the +X side of the first measurement unit 51 are the same as the first Z support arms 6A1 and 6A2 arranged at the side edge of the -X side of the first measurement unit 51. That is, of the first Z support arms 6A1 and 6A2 at the +X side of the first measurement unit 51, the first Z support arm 6A1 arranged at the +Z side is arranged parallel to the Y direction, and the first Z support arm 6A2 arranged at the -Z side is arranged inclined with respect to the Y direction.

[0057] The second Z support arms 6B1 and 6B2 on the +X side of the second measuring unit 52 are similar to the second Z support arms 6B1 and 6B2 on the -X side of the second measuring unit 52. The second Z support arm 6B1 on the -Z side is arranged parallel to the Y direction, and the second Z support arm 6B2 on the +Z side is arranged obliquely with respect to the Y direction. Figure 3As shown in FIG. 1 , the two first Z support arms 6A1 and 6A2 connected to the side edge on the +X side of the first measuring section 51 are arranged at positions closer to the +X side by a predetermined dimension than the two second Z support arms 6B1 and 6B2 connected to the side edge on the +X side of the second measuring section 52. Therefore, the +X side end edge of the first plate 512 of the first measuring section 51 protrudes toward the +X side relative to the +X side end edge of the second plate 522.

[0058] like Figure 3 As shown, of the two first X support arms 6C1 and 6C2 connected to the side edge of the +Z side of the first measurement unit 51, the first X support arm 6C1 on the -X side is arranged parallel to the Y direction, and the first X support arm 6C2 on the +X side is arranged inclined relative to the Y direction (inclined toward the -X side as it goes toward the +Y side). The same is true for the two second X support arms 6D1 and 6D2 connected to the side edge of the -Z side of the second measurement unit 52. The second X support arm 6D1 on the -X side is arranged parallel to the Y direction, and the second X support arm 6D2 on the +X side (see Figure 6 ) is configured to be inclined relative to the Y direction (inclined toward the -X side as it goes toward the +Y side).

[0059] The first X support arms 6C1 and 6C2 and the second X support arms 6D1 and 6D2 are arranged at positions symmetrical with respect to an XY plane passing through the centers of the first measurement unit 51 and the second measurement unit 52 .

[0060] (Detailed Structure of Each Arm 6)

[0061] Each of these arms 6 includes an arm body 61, a fixing piece 62, an arm support portion 63, and an adjustment screw 64. In addition, the arm fixing mechanism of the present disclosure is composed of the fixing piece 62, the arm support portion 63, and the adjustment screw 64.

[0062] (Structure of the Arm Body 61)

[0063] The arm body 61 is a long flat plate member formed of a material with a low thermal expansion coefficient such as Invar.

[0064] Among them, the arm body 61 of the first Z support arm 6A1, 6A2 and the second Z support arm 6B1, 6B2 arranged on the side (±X side) of the measuring unit 5 is arranged in a manner that the plane direction of the plate is along the ZY plane. As a result, the deflection of the arm body 61 in the Z direction caused by the gravity of the measuring unit 5 can be suppressed. In addition, the first X support arm 6C1, 6C2 and the second X support arm 6D1, 6D2 arranged on the +Z side of the first measuring unit 51 are arranged in a manner that the plane direction of the plate is along the XY plane. As a result, the displacement of the first measuring unit 51 and the second measuring unit 52 in the X direction can be suppressed.

[0065] In the present embodiment, in the first Z support arm 6A1, the second Z support arm 6B1, and the X support arm (the first X support arm 6C1, 6C2, the second X support arm 6D1, 6D2), the top view shape (the shape viewed from the thickness direction) of the arm main body 61 is a straight line. On the other hand, in the first Z support arm 6A2 and the second Z support arm 6B2, the top view shape (the shape viewed from the thickness direction) of the arm main body 61 is a bent shape. Hereinafter, the arm main body 61 having a straight line shape in top view will be referred to as a straight arm main body 61A, and the arm main body 61 having a bent shape will be referred to as a bent arm main body 61B.

[0066] like Figure 2 As shown, the linear arm body 61A comprises: a linear portion 611 having a pair of parallel linear edges along the longitudinal direction; a frame side arm end 612 having an arc-shaped edge on the frame body 4 side of the linear portion 611; and a measuring portion side arm end 613 on the measuring portion 5 side of the linear portion 611.

[0067] The frame-side arm end portion 612 is rotatably supported by the arm support portion 63 at a frame-side rotation axis 612A.

[0068] Furthermore, the measurement section side arm end portion 613 is rotatably connected to the first plate 512 or the second plate 522 of the measurement section 5 at the measurement section side rotation axis 613A.

[0069] On the other hand, Figure 2 As shown, the bending arm body 61B has a frame side arm end 612 , a first bending portion 614 , a second bending portion 615 , and a measurement portion side arm end 613 .

[0070] The frame-side arm end portion 612 has a semicircular end edge on the frame body 4 side similarly to the linear arm body 61A, and is rotatably supported by the arm support portion 63 .

[0071] The measurement section side arm end portion 613 has a semicircular end edge on the measurement section 5 side similarly to the linear arm body 61A, for example, and is rotatably connected to the first plate 512 or the second plate 522 of the measurement section 5 .

[0072] The bending arm body 61B extends in the longitudinal direction from the frame side arm end 612, and is bent in the approximate Z direction at the first bending portion 614. The longitudinal direction of the arm body 61 is the direction from the frame side rotation axis 612A toward the measurement unit side rotation axis 613A, and is hereinafter sometimes referred to as the Xarm direction (see Figure 4A , Figure 4B , Figure 5). In addition, the width direction of the arm body 61 perpendicular to the Xarm direction (the direction perpendicular to the Xarm direction in the plane direction of the planar plate-shaped arm body 61) is sometimes referred to as the Yarm direction (refer to Figure 4A , Figure 4B , Figure 5 ), the thickness direction of the planar plate-shaped arm body 61 is referred to as the Zarm direction (refer to Figure 4A , Figure 4B , Figure 5 ).

[0073] In the bending arm body 61B, the first bending portion 614 is bent from the Xarm direction to the Z direction from the frame side arm end 612 toward the measurement part side arm end 613, and is bent toward the +Xarm side at the second bending portion 615, and extends from the second bending portion 615 along the Xarm direction, so that the tip portion thereof becomes the measurement part side arm end 613. The width of the second bending portion 615 in the Z direction is large at the side of the first bending portion 614, and the width in the Z direction decreases toward the measurement part side arm end 613. As a result, the width dimensions of the first bending portion 614 and the second bending portion 615 in the Z direction are increased, and the deflection of the bending arm body 61B in the Z direction is further suppressed.

[0074] (Structure of the fixing plate 62)

[0075] Figure 4A , Figure 4B 2 is a diagram showing an arm fixing mechanism of the arm 6. Figure 4A This is a top view of a part of the arm 6 disposed on the -X side as viewed from the -X side. Figure 4B yes Figure 4A BB line cross-sectional view. Figure 5 It is a cross-sectional view of a part of the arm 6 cut by the Xarm-Yarm plane passing through the middle position in the thickness direction (Zarm direction). In addition, Figure 4A , Figure 4B as well as Figure 5 Although the figure shows a structural example of the arm 6 having the bent arm body 61B, the arm 6 having the straight arm body 61A has the same structure.

[0076] As described above, the fixing piece 62 is fixed to the arm fixing portion 42 of the frame body 4 (see Figure 5 The fixing piece 62 is a plate-shaped member formed of metal or the like, and is fixed to the frame body 4 by a predetermined fixing member. Figure 4A , Figure 4BAs shown in the figure, the fixing piece 62 is fixed to the frame body 4 by screwing. In addition, the fixing method of the fixing piece 62 is not limited to this, and it can also be fixed by an adhesive, or both an adhesive and screwing, and other fixing methods are also possible.

[0077] Furthermore, the fixing piece 62 is provided with an adjustment hole through which the adjustment screw 64 is inserted.

[0078] (Structure of the arm support portion 63)

[0079] like Figure 4A , Figure 4B as well as Figure 5 As shown, the arm support portion 63 is mounted on the fixing piece 62 via an adjustment screw 64. Specifically, the arm support portion 63 includes a support adjustment portion 631 and a rotation support portion 632 substantially along the longitudinal direction (Xarm direction) of the arm body 61.

[0080] The support adjustment portion 631 is formed with a threaded hole 633 for threading with the adjustment screw 64 (see Figure 5 ).

[0081] In addition, a force-applying portion 634 is provided between the support adjustment portion 631 and the fixing piece 62. As these force-applying portions 634, springs, etc. can be exemplified, which apply force to the arm support portion 63 in a direction away from the fixing piece 62. In addition, in the present embodiment, a spring is exemplified as the force-applying portion 634, but other force-applying members such as elastic rubber can also be used. In addition, in the present embodiment, a structural example in which two springs are provided across the threaded hole 633 is shown, but, for example, a structure in which a single spring is provided with the threaded hole 633 and the adjustment screw 64 threadedly connected to the threaded hole 633 as the central axis, or a structure in which three or more springs are arranged can also be provided.

[0082] In this embodiment, the arm support part 63 of the support arm body 61 can be moved forward and backward relative to the fixing piece 62 by rotating the adjustment screw 64, thereby extending and retracting the arm 6. This allows fine adjustment of the length of each arm and fine adjustment of the position and posture of the measurement unit 5 relative to the frame body 4.

[0083] In addition, if Figure 4A As shown, a positioning hole 638 is provided on the surface on the +Zarm side of the arm support portion 63. The positioning hole 638 is a threaded hole for threading with the fixing bolt 43.

[0084] The cover surface of the frame body 4 is arranged on the +Zarm side of the arm support part 63, and the fixing bolt 43 passes through the hole provided in the cover surface and is screwed into the positioning hole 638. By tightening the fixing bolt 43, the head 431 of the fixing bolt 43 is pressed against the cover surface of the frame body 4, so that the position of the arm support part 63 relative to the frame body 4 is firmly fixed.

[0085] The rotation support portion 632 of the arm support portion 63 supports the frame side arm end portion 612 of the arm body 61 so as to be rotatable. Figure 4A , Figure 4B as well as Figure 5 As shown, the rotation support portion 632 is provided with a groove portion 635 of a predetermined depth from the +Zarm side to the -Zarm side when viewed from the Zarm direction. The groove portion 635 is formed in a substantially U-shape opening at the end portion (+Xarm side) on the arm body 61 side, and the frame side arm end portion 612 is arranged in such a manner that the arm body 61 extends from the opening portion to the +Xarm side.

[0086] (Support Structure of Arm Body 61)

[0087] Next, the support structure of the arm main body 61 with respect to the arm support portion 63 will be described in detail.

[0088] like Figure 4B As shown, a shaft press hole 635A is provided at the bottom of the groove portion 635, and a press-in shaft portion 636B of the shaft support portion 636 is fitted into the shaft press hole 635A. The shaft support portion 636 is provided with a shaft hole portion 636A having an axis parallel to the Z arm direction.

[0089] On the other hand, Figure 4B As shown, an axial hole 616A penetrating in the Zarm direction is provided at the frame side arm end 612 of the arm body 61, and a fitting member 616B is fitted into the axial hole 616A. The fitting member 616B is provided with a support shaft through hole 616C penetrating in the Zarm direction, and a frame side rotating shaft 612A is inserted into the support shaft through hole 616C. The shaft diameter (diameter dimension orthogonal to the Zarm direction) of the frame side rotating shaft 612A is slightly smaller than the hole diameter (diameter dimension orthogonal to the Zarm direction) of the support shaft through hole 616C. A head 612A1 is provided at the end of the +Zarm side of the frame side rotating shaft 612A. The dimension of the head 612A1 orthogonal to the Zarm direction is larger than the hole diameter of the support shaft through hole 616C, and a spring 616D is arranged between the head 612A1 and the fitting member 616B. In addition, a threaded portion 612A2 that passes through the shaft hole portion 636A is provided at the end portion on the -Zarm side of the frame-side rotation shaft 612A.

[0090] The arm body 61 is axially supported so as to be rotatable relative to the arm support portion 63 .

[0091] For example, in this embodiment, a concave conical side tapered surface (axial support side tapered surface 637) centered on the axis of the shaft hole portion 636A is formed on the surface on the +Zarm side of the shaft support portion 636. Furthermore, a convex conical tapered surface (arm body side tapered surface 616E) is formed on the surface on the -Zarm side of the fitting member 616B.

[0092] By pressing the press-fit shaft portion 636B of the shaft support portion 636 into the shaft press-fit hole 635A, the frame side rotation shaft 612A is fixed to the arm support portion 63. The fitting member 616B is biased toward the -Zarm side by the spring 616D, whereby the shaft support side tapered surface 637 is fitted into the arm body side tapered surface 616E.

[0093] In the present embodiment, according to the above configuration, the arm body 61 is rotatably supported by the arm support portion 63 .

[0094] In addition, in this embodiment, if Figure 4B As shown, a gap S is formed between the U-shaped side wall 639 forming the groove 635 of the arm support portion 63 and the side wall 617 of the arm body 61. Thus, the arm body 61 is allowed to rotate relative to the arm support portion 63 by an amount corresponding to the gap S, and dimensional changes caused by thermal expansion of the frame body 4, for example, can be absorbed.

[0095] (Connection of Arm Body 61 to Measuring Unit 5)

[0096] The connection structure of the measurement section side arm end portion 613 of the arm body 61 with respect to the measurement section 5 may be, for example, a structure similar to the structure of the frame side rotation shaft 612A described above.

[0097] That is, a second axial hole (not shown) penetrating in the Zarm direction is provided in the measurement unit side arm end portion 613 of the arm body 61, and a measurement unit side rotation shaft 613A having the same structure as the frame side rotation shaft 612A is inserted into the second axial hole.

[0098] In addition, an axis support portion having the same structure as the axis support portion 636 of the arm support portion 63 is fixed to the plate portion (first plate 512, second plate 522) of the measuring portion 5, and the press-in axis portion of the frame side rotating shaft 612A is pressed into the axis press-in hole of the axis support portion.

[0099] [Position of the Fixed Point of the Arm 6 in the Measurement Device 1]

[0100] In this embodiment, Figure 2In the projection view as viewed from the X direction, the first Z support arms 6A1 and 6A2 connected to the side edges of the ±X sides of the first measurement section 51 and the second Z support arms 6B1 and 6B2 connected to the side edges of the ±X sides of the second measurement section 52 are symmetrical with respect to a reference line L0 that passes through the middle point between the first measurement section 51 and the second measurement section 52 and is parallel to the Y direction. Among them, the first Z support arm 6A1 disposed on the +Z side of the first Z support arms 6A1 and 6A2 and the second Z support arm 6B1 disposed on the −Z side of the second Z support arms 6B1 and 6B2 form a pair, and the first Z support arm 6A2 and the second Z support arm 6B2 form a pair and are symmetrical with respect to the reference line L0.

[0101] In this embodiment, the Y coordinate of the fixed position of the paired first Z support arm 6A1 relative to the frame body 4 and the Y coordinate of the fixed position of the second Z support arm 6B1 relative to the frame body 4 are the same coordinates. Similarly, the Y coordinate of the fixed position of the paired first Z support arm 6A2 relative to the frame body 4 and the Y coordinate of the fixed position of the second Z support arm 6B2 relative to the frame body 4 are the same coordinates. The fixed position relative to the frame body 4 refers to the contact point between the fixed piece 62 fixed relative to the frame body 4 and the adjustment screw 64.

[0102] In other words, Figure 2 In the projection view viewed from the X direction, the first Z support arm 6A1 and the second Z support arm 6B1 are arranged so as to be aligned on an imaginary straight line L1 (first imaginary line) parallel to the Z direction at the fixed positions relative to the frame body 4. Similarly, the first Z support arm 6A2 and the second Z support arm 6B2 are arranged so as to be aligned on an imaginary straight line L2 (first imaginary line) parallel to the Z direction at the fixed positions relative to the frame body 4.

[0103] In the first Z support arms 6A1, 6A2 and the second Z support arms 6B1, 6B2, the measurement unit side rotation axis 613A of each arm body 61 is rotatably connected to the first plate 512 or the second plate 522 of the measurement unit 5. That is, the measurement unit side rotation axis 613A is a fixed position of the first Z support arms 6A1, 6A2 and the second Z support arms 6B1, 6B2 relative to the measurement unit 5.

[0104] The Y coordinates of the fixed positions of the paired first Z support arms 6A1 with respect to the first measuring unit 51 and the Y coordinates of the fixed positions of the second Z support arms 6B1 with respect to the second measuring unit 52 are the same coordinates. Similarly, the Y coordinates of the fixed positions of the paired first Z support arms 6A2 with respect to the first measuring unit 51 and the Y coordinates of the fixed positions of the second Z support arms 6B2 with respect to the second measuring unit 52 are the same coordinates. In addition, in the present embodiment, the Y coordinates of the fixed positions of the four arms 6, namely, the first Z support arms 6A1, 6A2 and the second Z support arms 6B1, 6B2 with respect to the measuring unit 5 are the same position, that is, they are arranged in a manner arranged on an imaginary straight line L3 (second imaginary line) parallel to the Z direction in the projection view observed from the X direction.

[0105] Figure 6 It is a schematic perspective view showing the positional relationship between the first X support arms 6C1 and 6C2 and the second X support arms 6D1 and 6D2.

[0106] The first X support arms 6C1 and 6C2 connected to the side edge of the +Z side of the first measurement section 51 and the second X support arms 6D1 and 6D2 connected to the side edge of the -Z side of the second measurement section 52 are arranged symmetrically with respect to an XY plane (reference plane) passing through the midpoint between the first measurement section 51 and the second measurement section 52. Of the first X support arms 6C1 and 6C2 and the second X support arms 6D1 and 6D2 symmetrical with respect to the reference plane, the first X support arm 6C1 and the second X support arm 6D1 form a pair, and the first X support arm 6C2 and the second X support arm 6D2 form a pair.

[0107] Furthermore, the X coordinates (and Y coordinates) of the first X support arm 6C1 and the second X support arm 6D1, which are paired with each other, are the same coordinates at the fixed position relative to the frame body 4. Similarly, the X coordinates (and Y coordinates) of the first X support arm 6C2 and the second X support arm 6D2, which are paired with each other, are the same coordinates at the fixed position (measurement unit side rotation axis 613A) relative to the frame body 4. In addition, as described above, the fixed position relative to the frame body 4 refers to the contact point between the fixing piece 62 fixed to the frame body 4 and the adjustment screw 64.

[0108] Furthermore, the X coordinate (and Y coordinate) of the fixed position of the paired first X support arm 6C1 relative to the first measurement unit 51 and the X coordinate (and Y coordinate) of the fixed position of the second X support arm 6D1 relative to the second measurement unit 52 are the same coordinates. Similarly, the X coordinate (and Y coordinate) of the fixed position of the paired first X support arm 6C2 relative to the first measurement unit 51 and the X coordinate (and Y coordinate) of the fixed position of the second X support arm 6D2 relative to the second measurement unit 52 are the same coordinates.

[0109] According to the above-described configuration, even if a dimensional variation of the frame body 4 due to a temperature change occurs, the variation can be absorbed.

[0110] That is, the arm body 61 of the present embodiment is formed of a raw material having an extremely small thermal expansion coefficient such as invar, and therefore, the dimensional change of each arm 6 due to temperature change is sufficiently negligible. On the other hand, there is a possibility that the size of the frame body 4 changes slightly due to temperature change. However, according to the above-mentioned structure, the amount of posture change of the first measuring part 51 relative to the frame body 4 and the amount of posture change of the second measuring part 52 relative to the frame body 4 caused by the dimensional change of the frame body 4 are the same, and as a result, the positional relationship between the first measuring part 51 and the second measuring part 52 is maintained. Therefore, the relative position of the second measuring part 52 with respect to the first measuring part 51 is not affected by the dimensional change of the frame body 4 caused by temperature change, and the undesirable situation of the position change of the first measuring part 51 and the second measuring part 52 relative to the reference line L0 caused by this can be suppressed.

[0111] [Effects of this embodiment]

[0112] The measuring device 1 of this embodiment includes: a holding portion 31, which is used to hold the object to be measured W; a measuring portion 5 (a first measuring portion 51, a second measuring portion 52), which is arranged at a position opposite to the holding portion 31 and includes measuring sensors 511, 521 for performing measurement processing on the object to be measured W; a frame body 4; and a plurality of arms 6, which connect the frame body 4 and the measuring portion 5.

[0113] In such a measuring device 1, it is easier to perform maintenance on the measuring section 5. That is, in a conventional measuring device in which the measuring sensor is directly fixed to the frame body, it is necessary to operate the frame body, and the contact with the measuring sensor is poor, making it difficult to maintain. For example, in order to adjust the position of the measuring sensor, it is necessary to directly adjust the fixing structure of the measuring sensor fixed to the frame body, and it is necessary to disassemble the frame body to expose the measuring sensor. In contrast, in the present embodiment, even if it is desired to fine-tune the position and posture of the measuring section 5 relative to the frame body 4 before using the measuring device 1, the position and posture of the measuring section 5 can be easily adjusted by fine-tuning the length of the arm 6. In addition, the arm 6 is used to separate the frame body 4 from the measuring section 5, and a gap is generated between the frame body 4 and the measuring section 5, thereby making it easy to contact the measuring section 5 from the gap, and the adjustment operation of the arm 6 is also easy.

[0114] In addition, in the measuring device 1 of the present embodiment, as long as the arm body 61 is formed of a raw material such as invar with a small thermal expansion coefficient, the influence of temperature changes can be reduced. That is, in the case of a structure in which the measuring sensor is directly fixed to the frame body as in the previous measuring device, in order to suppress the displacement of the measuring sensor caused by temperature changes, it is necessary to form the entire frame body with a raw material with a small thermal expansion coefficient to suppress the influence of temperature changes, so the cost is high. In contrast, in the measuring device 1 of the present embodiment, only the arm body 61 is formed of a raw material with a small thermal expansion coefficient, and the entire frame body 4 does not need to be formed of a raw material with a small thermal expansion coefficient, and any raw material can be used. Therefore, the cost of the measuring device 1 can be reduced.

[0115] In the measuring device 1 of this embodiment, the multiple arms 6 include multiple Z support arms (first Z support arms 6A1, 6A2, second Z support arms 6B1, 6B2) arranged along the Z direction and multiple X support arms (first X support arms 6C1, 6C2, second X support arms 6D1, 6D2) arranged along the X direction.

[0116] In such a structure, the Z support arm can be used to suppress the movement of the measurement unit 5 in the Z direction, and the X support arm can be used to limit the movement of the measurement unit 5 in the X direction. In addition, the position of the measurement unit 5 in the Y direction is defined by the Z support arm and the X support arm, so the movement in the Y direction can also be limited. Therefore, the position of the measurement unit 5 can be fixed at an arbitrary position relative to the frame body 4.

[0117] In the measuring device 1 of the present embodiment, the measuring unit 5 comprises: a first measuring unit 51, which is arranged at a position opposite to the +Z side (first side) of the object to be measured W held by the holding unit 31; and a second measuring unit 52, which is arranged at a position opposite to the -Z side (second side) of the object to be measured W, and the first measuring unit 51 and the second measuring unit 52 are respectively connected to the frame body 4 using a plurality of arms 6.

[0118] Thus, the surface shape of the +Z side surface and the surface shape of the -Z side surface of the object W can be measured simultaneously.

[0119] In particular, when the SIM sensor is used to measure the object W with a light-transmitting WLO as the object W, the surface shape and the back shape at the same point are measured by setting the measurement axis of the first measurement unit 51 and the measurement axis of the second measurement unit 52 to be the same axis. In this embodiment, the positions and postures of the first measurement unit 51 and the second measurement unit 52 can be easily adjusted, and the measurement axis of the first measurement unit 51 and the measurement axis of the second measurement unit 52 can be appropriately matched.

[0120] In the present embodiment, in the projection view observed from the X direction, the first Z support arms 6A1, 6A2 and the second Z support arms 6B1, 6B2 are respectively arranged at positions symmetrical with respect to the reference line L0, and the first Z support arm 6A1 and the second Z support arm 6B1 that are paired with each other are arranged on the imaginary straight line L1 that is the first imaginary line. Similarly, the first Z support arm 6A2 and the second Z support arm 6B2 that are paired with each other are arranged on the imaginary straight line L2 that is the first imaginary line. Moreover, the fixed position of the first Z support arm 6A1 with respect to the first measurement unit 51 and the fixed position of the second Z support arm 6B1 with respect to the second measurement unit 52 are arranged on the imaginary straight line L3 that is the second imaginary line. Similarly, the fixed position of the first Z support arm 6A2 with respect to the first measurement unit 51 and the fixed position of the second Z support arm 6B2 with respect to the second measurement unit 52 are arranged on the imaginary straight line L3.

[0121] Thus, the first Z support arm 6A1, 6A2 and the second Z support arm 6B1, 6B2 can be used to control dimensional changes such as strain of the frame body 4 caused by temperature changes, and the deviation in the positional relationship between the first measuring part 51 and the second measuring part 52 caused by the dimensional changes of the frame body and the resulting measurement errors can be suppressed.

[0122] In the measuring device of this form, the first X-supporting arms 6C1 and C2 and the second X-supporting arms 6D1 and D2 are respectively arranged at positions symmetrical with respect to the reference plane, and the first X-supporting arm 6C1 and the second X-supporting arm 6D1 that form a pair have the same X coordinates of the fixed positions relative to the frame body 4. Similarly, the first X-supporting arm 6C2 and the second X-supporting arm 6D2 that form a pair have the same X coordinates of the fixed positions relative to the frame body 4.

[0123] In addition, the X coordinate of the fixed position of the first X support arm 6C1 relative to the first measurement unit 51 is the same as the X coordinate of the fixed position of the second X support arm 6D1 relative to the second measurement unit 52. Similarly, the X coordinate of the fixed position of the first X support arm 6C2 relative to the first measurement unit 51 is the same as the X coordinate of the fixed position of the second X support arm 6D2 relative to the second measurement unit 52.

[0124] Therefore, as described above, the first X-support arm 6C1, 6C2 and the second X-support arm 6D1, 6D2 can be used to control dimensional changes such as strain of the frame body 4 caused by temperature changes, and the deviation of the positional relationship between the first measuring part 51 and the second measuring part 52 caused by the dimensional change of the frame body and the resulting measurement error can be suppressed.

[0125] In the measurement device 1 of the present embodiment, each of the plurality of arms 6 is configured such that the length in the longitudinal direction of the arm 6 can be extended and retracted.

[0126] Thus, by extending and retracting the arm 6 , the position and posture of the measurement unit 5 relative to the frame body 4 can be easily adjusted.

[0127] Specifically, the arm 6 includes a longitudinally-shaped arm main body 61 and an arm fixing mechanism disposed at an end portion of the arm main body 61 on the side of the frame main body 4 in the longitudinal direction, the arm fixing mechanism including: a fixing plate 62 fixed to the frame main body 4; an arm support portion 63 supporting the arm main body 61 so as to be rotatable; and an adjustment screw member 64 serving as an adjustment portion of the present application, which connects the fixing plate 62 and the arm support portion 63 so that the position of the arm support portion 63 relative to the fixing plate 62 can be advanced and retreated along the longitudinal direction of the arm main body 61.

[0128] Thus, by rotating the adjustment screw 64 , the arm support portion 63 can be moved forward and backward relative to the fixing piece 62 , and the length of the arm 6 in the longitudinal direction (Xarm direction) can be easily adjusted.

[0129] [Modifications]

[0130] In addition, the present invention is not limited to the above-mentioned embodiment, and also includes the following modifications within the scope that can achieve the object of the present invention.

[0131] [Modification 1]

[0132] In the above embodiment, the first measuring unit 51 is supported by six arms 6, namely, two arms 6 on the +X side, two arms 6 on the -X side, and two arms 6 on the +Z side. However, the first measuring unit 51 may be supported by seven or more arms 6. For example, the first measuring unit 51 may be supported by three or more arms 6 on the ±X side, and three or more arms 6 on the +Z side. The same is true for the second measuring unit 52.

[0133] In addition, the arm 6 on the +Z side of the side (±X side) of the first measuring unit 51 is parallel to the Y direction, and the arm 6 on the -Z side is set to be an arm 6 that is inclined toward the +Z side as it goes toward the Y direction, but it is not limited to this. For example, the arm 6 on the +Z side of the side of the first measuring unit 51 may be inclined relative to the Y direction, and the arm on the -Z side may be parallel to the Y direction. In addition, both arms 6 may be parallel to the Y direction, and both arms 6 may be inclined relative to the Y direction.

[0134] The same applies to the arm 6 disposed on the +Z side of the first measurement unit 51 and the arms 6 supporting the second measurement unit 52 .

[0135] [Modification 2]

[0136] In the above embodiment, the fixing piece 62, the arm support portion 63, and the adjustment screw 64 as the arm fixing mechanism are provided on the frame body 4 side of the arm 6, but the same arm fixing mechanism may be provided on the measuring portion 5 side of the arm 6. The same arm fixing mechanism may be provided on both ends of the arm 6.

[0137] [Variation 3]

[0138] In the above embodiment, an example is shown in which the measuring unit 5 includes the first measuring unit 51 and the second measuring unit 52 , but only the first measuring unit 51 may be provided, or three or more measuring units may be provided.

[0139] [Variation 4]

[0140] In the above embodiment, as a structure for changing the length of the arm 6, a mechanism for adjusting the distance between the fixing piece 62 and the arm support portion 63 by the adjustment screw 64 in the arm fixing mechanism provided at one end of the arm body 61 is exemplified, but the present invention is not limited thereto.

[0141] For example, the structure that enables the arm body 61 to be extended and retracted may be arranged in the middle position of the arm body 61. As a specific example, an example of dividing the arm body into a plurality of small arm components may be cited. For example, the following structure is provided: the arm body is composed of a first component and a second component, and the second component can move relative to the first component along the longitudinal direction. In addition, the length of the entire arm body may be adjusted by fixing the first component and the second component at a position where the desired length is obtained using a screw or the like.

Claims

1. A measuring device, wherein: The measuring device has: A holding portion for holding an object to be measured; a measuring unit provided at a position opposite to the holding unit and including a sensor for performing a measuring process on the object to be measured; Framework body; as well as A plurality of arms connect the frame body and the measuring unit.

2. The measuring device according to claim 1, wherein A direction from the measuring unit toward the object to be measured is defined as a Z direction, a direction perpendicular to the Z direction is defined as an X direction, and a direction perpendicular to the X direction and the Z direction and from the frame body toward the measuring unit is defined as a Y direction. The plurality of arms include a plurality of Z support arms arranged along the Z direction and a plurality of X support arms arranged along the X direction.

3. The measuring device according to claim 2, wherein: The measuring unit comprises: a first measuring unit arranged at a position opposite to a first surface of the object to be measured held by the holding unit; and a second measuring unit arranged at a position opposite to a second surface of the object to be measured held by the holding unit and opposite to the first surface. The first measurement section and the second measurement section are respectively connected to the frame body by the plurality of arms.

4. The measuring device according to claim 3, wherein: The plurality of Z support arms include a plurality of first Z support arms supporting the first measurement unit and a plurality of second Z support arms supporting the second measurement unit. In the projection view observed from the X direction, the plurality of first Z support arms and the plurality of second Z support arms are respectively arranged at positions symmetrical with respect to a reference line, the reference line includes a midpoint between the first measurement portion and the second measurement portion and is parallel to the Y direction, The fixed position of the first Z support arm relative to the frame body and the fixed position of the second Z support arm relative to the frame body which is symmetrical to the first Z support arm relative to the reference line are arranged on a first imaginary line parallel to the Z direction, A fixed position of the first Z support arm relative to the first measurement unit and a fixed position of the second Z support arm symmetrical to the first Z support arm relative to the reference line relative to the second measurement unit are arranged on a second imaginary line parallel to the Z direction.

5. The measuring device according to claim 3, wherein: The plurality of X-support arms include a plurality of first X-support arms supporting the first measurement unit and a plurality of second X-support arms supporting the second measurement unit. The plurality of first X support arms and the plurality of second X support arms are respectively arranged in positions symmetrical with respect to a reference plane in the Z direction, the reference plane including a midpoint between the first measurement portion and the second measurement portion and being parallel to the XY plane, The coordinate in the X direction of the fixed position of the first X support arm relative to the frame body is the same as the coordinate in the X direction of the fixed position of the second X support arm relative to the frame body which is symmetrical with the first X support arm relative to the reference plane. The X-direction coordinate of the fixed position of the first X support arm relative to the first measurement unit is the same as the X-direction coordinate of the fixed position of the second X support arm symmetrical to the first X support arm relative to the reference plane relative to the second measurement unit.

6. The measuring device according to claim 1, wherein Each of the plurality of arms is configured so that the length in the longitudinal direction of the arm can be extended or retracted.

7. The measuring device according to claim 6, wherein: The arm comprises: a longitudinally long arm body; and an arm fixing mechanism provided at least one of an end portion on the frame body side and an end portion on the measuring unit side in the longitudinal direction of the arm body, The arm fixing mechanism comprises: A fixing piece fixed to the frame body or the measuring part; an arm support portion that supports the arm body so as to be rotatable; and The adjusting portion connects the fixing piece and the arm supporting portion so as to advance and retreat the position of the arm supporting portion relative to the fixing piece along the longitudinal direction of the arm body.

Images