JP5292668B2 - Shape measuring apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small shape measuring apparatus that can further accurately measure the surface shape and easily supports a stylus. <P>SOLUTION: An X driving device 50 disposed in an X-Y stage device 82 supports a movable section 52 in noncontact by air slide, and drives the movable section 52 with linear motors 51a and 51b, so that the motion related to the XY axial direction of a mounting stand 82a becomes smooth and highly accurate. A micro displacement in the Z-axis direction hardly occurs when an optical element OE is moved on the XY plane, the displacement amount measurement of the stylus 11 can be made accurate, and the measurement accuracy of the surface shape of the optical element OE can be raised. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention relates to a shape measuring apparatus and a shape measuring method for measuring the surface shape and the like of a lens and other optical elements.

Conventionally, various techniques have been proposed as techniques for measuring a three-dimensional shape (three-dimensional shape) of an optical element having a size of 50 mm or less, that is, a so-called microlens, as an object to be measured. For example, there is a contact-type measurement method in which a stylus is brought into direct contact with the surface of an object to be measured and the amount of displacement is measured (see Patent Document 1). In addition, a non-contact measurement method has been proposed in which a laser beam or the like is incident on the surface of an object to be measured and the surface irregularities are measured by receiving the reflected light (see Patent Document 2). The former contact-type measurement method does not depend on the surface physical properties of the object to be measured because the stylus is brought into direct contact with the object to be measured. For this reason, the contact-type measurement method can accurately measure various objects to be measured.
JP-A-5-209741 Japanese Patent No. 3046635

  In the contact measurement method, (1) a method of measuring a displacement amount of the stylus while moving the mounting table side on which the object to be measured is placed in a horizontal plane using an XY driving device including a ball screw, a motor and the like. (2) A method of measuring the displacement amount of the stylus while moving the stylus side in contact with the object to be measured in a horizontal plane using an XY driving device is conceivable.

  When the mounting table side is displaced by the XY driving device, the XY driving device generates fine vertical movement (specifically, vertical vibration of about 100 nm) when the object to be measured is displaced by the XY driving device. Smooth vertical movement affects the displacement measurement of the stylus, reducing the measurement accuracy and reproducibility of the surface shape.

  On the other hand, when the stylus side is displaced by the XY driving device, the XY driving device does not adversely affect the stylus displacement measurement itself, but the XY driving device is positioned on the stylus side, that is, on the upper side. Therefore, the shape measuring device including the structure that supports the XY drive device is increased in size and accuracy is difficult to ensure.

Therefore, an object of the present invention is to provide a compact shape measuring device and a shape measuring method by which surface shape can be measured with high accuracy and a stylus is simply supported.

In order to solve the above-described problem, the shape measuring apparatus according to the present invention can mount an optical element having a maximum dimension of 50 mm or less as an object to be measured on the upper surface side, and extend in the X direction extending orthogonally to each other in the horizontal direction. A mounting table that can move in the Y direction, and a stylus that is fixedly arranged in the X and Y directions, can contact the surface of the object to be measured, and can move in the Z direction perpendicular to the X and Y directions And a single Z measurement value by measuring the amount of movement of the stylus in contact with the measurement object in the Z direction by moving the measurement object mounted on the mounting table in a two-dimensional manner in the horizontal direction. And a movement measuring means for obtaining a corresponding Z position from the driving means for moving the mounting table in a two-dimensional manner in a horizontal direction while supporting the mounting table in a non-contact manner in the horizontal direction. It has a guide part to guide, the guide part is horizontal Has two guide mechanisms for guiding the mounting table in the X and Y directions orthogonal to extend, each of the two guiding mechanism comprises a linear motor for applying a driving force in each direction in a non-contact state, air slide The guide unit has two guide mechanisms in two upper and lower stages, and the upper guide mechanism of the two guide mechanisms has a stroke amount equal to or larger than the size of the object to be measured, and the lower guide mechanism Compared to the guide mechanism, the stroke amount is equivalent or less.

In the shape measuring apparatus, since the driving means includes the linear motor and the air slide that apply driving force in the X direction and the Y direction in a non-contact state with respect to the mounting table, the movement of the mounting table in the X direction and the Y direction. Is smooth and accurate. Therefore, when moving the object to be measured in the X direction and the Y direction, minute displacements in the Z direction , which is the vertical direction perpendicular to these, are unlikely to occur, so that the movement of the stylus, that is, the amount of displacement is accurately measured. Thus, measurement accuracy and reproducibility of the surface shape can be improved.
Further, in the shape measuring apparatus, the mounting table can mount an optical element having a maximum dimension of 50 mm or less as an object to be measured. In this case, if the object to be measured is moved in the X and Y directions with respect to the stylus, there is a high possibility that a minute displacement in the Z direction will affect the measurement. By making it move, measurement accuracy can be improved effectively.
Further, in the shape measuring apparatus, the guide unit has two guide mechanisms in two upper and lower stages for guiding the mounting table in a biaxial direction extending orthogonally to the horizontal direction as a predetermined direction. Of the two guide mechanisms, The upper guide mechanism realizes a stroke amount that is equal to or larger than the size of the object to be measured and is equal to or smaller than the lower guide mechanism. In this case, it is possible to prevent the upper guide mechanism from becoming large and preventing stable installation of the shape measuring apparatus.

In a specific aspect or viewpoint of the present invention, a holder for holding an object to be measured is provided on the mounting table.

  In another aspect of the present invention, there is a lock means for locking the guide table and fixing the mounting table. In this case, it is possible to prevent the guide part, the stylus, the object to be measured, and the like from being damaged by fixing the mounting table by the locking means at the necessary timing, specifically, at the time of an emergency stop of measurement or when the object to be measured is attached or detached.

  In another aspect of the present invention, the relatively displaceable movable portion provided in the guide portion is formed of a ceramic material. In this case, it is possible to prevent the size from being changed even if a temperature change occurs due to heat generated by the linear motor or the like, so that the guide portion can be operated with high accuracy and the measurement accuracy of the surface shape can be improved. .

  In yet another aspect of the present invention, a mirror provided on the mounting table and a laser light source that emits laser light for length measurement to the mirror are provided, and in a predetermined direction based on return light from the mirror. Auxiliary measuring means for detecting the displacement of the mounting table in a certain horizontal direction is further provided, and the laser light source and the mirror are arranged at a height position corresponding to the stylus. In this case, the horizontal displacement of the mounting table can be detected at the height position of the stylus, and the horizontal position of the object to be measured with respect to the stylus can be detected more accurately. It is more desirable that the laser light source or the like is disposed at a height position corresponding to the tip of the stylus.

  In still another aspect of the present invention, the optical system further includes shielding means having a double cylindrical portion that covers the optical path from the laser light source to the mirror and enables expansion and contraction in the axial direction, and the length of each cylindrical portion is driven. It is more than the stroke amount of the mounting table by the means. In this case, generation of measurement noise can be prevented by the shielding means to ensure stable operation, and movement of the mounting table can be ensured by setting the length of each cylindrical portion.

  In still another aspect of the present invention, the linear motor has a magnet part, and the magnet part is fixed to the movable part side of the guide part. In this case, since the coil portion of the linear motor is provided on the fixed portion side of the guide portion, the degree of freedom of movement on the movable portion side can be increased, and the wiring to the coil portion can be easily performed.

  In order to solve the above-described problems, the shape measuring apparatus according to the present invention can mount an optical element having a maximum dimension of 50 mm or less as an object to be measured on the upper surface side, and extend in the X direction and the Y direction extending orthogonally to each other in the horizontal direction. And a stylus that is fixedly arranged in the X and Y directions, can contact the surface of the object to be measured, and is movable in the Z direction perpendicular to the X and Y directions, A method for measuring the shape of an optical element using a shape measuring apparatus comprising: a driving means for moving a mounting table in a two-dimensional manner in a horizontal direction, wherein the driving unit guides the mounting table in a horizontal direction while supporting the mounting table in a non-contact manner. The guide section includes two guide mechanisms that guide the mounting table in the X direction and the Y direction extending orthogonally to the horizontal direction, and the two guide mechanisms are in a non-contact state, respectively. A linear motor that applies driving force in each direction; The guide unit has two guide mechanisms in two upper and lower stages, and the upper guide mechanism of the two guide mechanisms has a stroke amount larger than the size of the object to be measured. Compared with the lower guide mechanism, the stroke amount is equal to or less than that. An optical element having a maximum dimension of 50 mm or less is placed on the mounting table as a measurement object, and the mounting table is driven by a driving means. Thus, the optical element is moved two-dimensionally in the horizontal direction, and the corresponding Z position is obtained from the single Z measurement value by measuring the amount of movement of the stylus in contact with the optical element in the Z direction.

  Hereinafter, a shape measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIGS. 1A and 1B are a front view and a side view for explaining the structure of the shape measuring apparatus.

  This shape measuring apparatus 100 has a structure in which an XY stage device 82 and a Z driving device 84 are fixed on a surface plate 81. Here, the operations of the XY stage device 82 and the Z drive device 84 are controlled by the drive control unit 98 and the control device 99.

  The XY stage device 82 is driven and operated by the drive control unit 98 under the control of the control device 99. The XY stage device 82 smoothly moves the measurement jig HD, which is detachably fixed on the mounting table 82a provided on the top of the XY stage device 82, to an arbitrary position two-dimensionally in the XY plane. Can do. The measuring jig HD holds an optical element OE to be measured. The optical element OE held by the measurement jig HD is a so-called micro lens having a maximum dimension of 50 mm or less. Here, the maximum dimension means the diameter when the optical element OE has a circular outline, and means the long side when the optical element OE has a rectangular outline.

  The XY stage device 82 includes an X driving device 50 as a lower driving means and a Y driving device 60 as an upper driving means in two upper and lower stages. The former X driving device 50 includes a fixed-side support 51 fixed to the surface plate 81 side, and an X-axis direction that is disposed above the fixed-side support 51 and corresponds to a predetermined direction with respect to the fixed-side support 51. And a movable portion 52 that slides. Further, the latter Y driving device 60 has a fixed side support portion 61 fixed on the movable portion 52 of the X drive device 50 and a fixed side support portion 61 disposed above the fixed side support portion 61. And a movable portion 62 that slides in the Y-axis direction corresponding to the direction.

  In the X drive device 50, a coil portion 51a, which is a stator of the linear motor, is fixed to the bottom of the groove provided in the center of the fixed side support portion 51. On the other hand, at an appropriate position on the bottom surface of the movable portion 52, a magnet portion 51b which is a mover of the linear motor is fixedly provided so as to face the coil portion 51a. By supplying electric power from the drive control unit 98 to the coil unit 51a provided on the fixed side support unit 51, a thrust can be applied to the magnet unit 51b, and the movable unit 52 can be freely moved to an arbitrary position in the X-axis direction. It can be moved precisely. At one end of the movable part 52, a lock member LM1 for fixing the movable part 52 to the fixed side support part 51 at a necessary timing is provided as a locking means. The lock member LM1 is operated by an operator at the time of an emergency stop of measurement or at the time of attaching / detaching the measurement jig HD which is the object to be measured. Specifically, when the operator presses a lock button (not shown), a control signal is output from the control device 99 to the drive control unit 98 to stop power feeding to the coil portion 51a of the linear motor and to lock from the control device 99. A signal for driving the member LM1 is output, the lock member LM1 operates, and the sliding movement of the X driving device 50 is stopped. By operating the lock member LM1, it is possible to reliably prevent damage to the movable parts 51 and 52, the stylus 11, the optical element OE that is the object to be measured, and the like. Although not shown, the X drive device 50 is provided with a linear scale for feedback so that the position of the movable portion 52 can be precisely controlled.

  An air slide discharge port 51g is provided at an appropriate position on the upper surface of the fixed support 51. Controlled compressed air from the drive control unit 98 is supplied to the air slide discharge port 51g, and a controlled thin air layer is formed between the upper surface of the fixed side support unit 51 and the lower surface of the movable unit 52. The Accordingly, the movable portion 52 can be supported on the fixed-side support portion 51 in a non-contact manner, and the movement of the movable portion 52 and the mounting table 82a in the X-axis direction is smooth by cooperation with the linear motors 51a and 51b. High accuracy. The linear motors 51a and 51b can be provided with a non-contact support function. In this case, the linear motors 51a and 51b also partially serve as a guide unit.

  In the Y drive device 60, a coil portion 61 a that is a stator of the linear motor is fixed to the groove bottom portion provided in the center of the fixed side support portion 61. On the other hand, at an appropriate position on the bottom surface of the movable portion 62, a magnet portion 61b which is a mover of the linear motor is fixedly provided so as to face the coil portion 61a. By supplying electric power from the drive control unit 98 to the coil unit 61a provided on the fixed side support unit 61, a thrust can be applied to the magnet unit 61b, and the movable unit 62 can be freely moved to an arbitrary position in the Y-axis direction. It can be moved precisely. At one end of the movable part 62, a lock member LM2 for fixing the movable part 62 to the fixed side support part 61 at a necessary timing is provided as a locking means. The lock member LM2 is the same as the lock member LM1, and is operated by an operator at the time of an emergency stop of measurement or when the object to be measured is attached or detached. By operating the lock member LM2, it is possible to reliably prevent damage to the movable parts 61 and 62, the stylus 11, the optical element OE that is the object to be measured, and the like. Although not shown, the Y driving device 60 is provided with a linear scale for feedback, and precise position control of the movable portion 62 is possible.

  An air slide discharge port 61g is provided at an appropriate position on the upper surface of the fixed support 61. Controlled compressed air from the drive control unit 98 is supplied to the air slide discharge port 61g, and a controlled thin air layer is formed between the upper surface of the fixed side support unit 61 and the lower surface of the movable unit 62. The Thereby, the movable part 62 can be supported on the fixed side support part 61 in a non-contact manner, and the movement of the movable part 62 and the mounting table 82a in the Y-axis direction is smooth by cooperation with the linear motors 61a and 61b. High accuracy. Note that the linear motors 61a and 61b may be provided with a non-contact support function, and in this case, the linear motors 61a and 61b also partially serve as a guide portion.

  In the above, the fixed side support portions 51 and 61 and the movable portions 52 and 62 are movable portions of the guide portion that are relatively displaced, and the main body portion is formed of a ceramic material such as silicon nitride. Thus, by forming the movable part with silicon nitride or the like, the rigidity of the movable part can be increased while reducing the weight. As a result, the size of the movable parts 51, 52, 61, 62 can be prevented from changing even if the temperature changes due to the heat generated by the linear motors 51a, 51b, 61a, 61b, etc. In addition, the Y driving device 60 can be operated with high accuracy, and the measurement accuracy of the surface shape of the optical element OE held by the measurement jig HD can be increased. The fixed support portions 51 and 61 and the movable portions 52 and 62 are not limited to silicon nitride or the like, and can be formed of various materials. However, the rigidity of these movable parts 51, 52, 61, 62 is desirably 180 N / μm or more from the viewpoint of preventing vertical vibration. Further, the wiring to the linear motors 51a, 51b, 61a, 61b and the piping to the air slide discharge ports 51g, 61g are made so as not to disturb the operation of the X driving device 50 and the Y driving device 60. The load is eliminated when moving 82a.

  Note that, when the stroke amount in the X direction of the X drive device 50 and the stroke amount in the Y direction of the Y drive device 60 are compared, both stroke amounts are set within 150 mm. This is larger than the stroke amount of the Y drive device 60. That is, the lower guide mechanisms 51 and 52 are larger than the upper guide mechanisms 61 and 62, and the structure of the XY stage device 82 can be stabilized. That is, it is possible to prevent the upper guide mechanisms 61 and 62 from becoming large and preventing the stable installation of the shape measuring apparatus 100 from being hindered.

  The position of the measurement jig HD on the XY stage device 82, that is, the optical element OE is detected by using the X mirror member 83a and the Y mirror member 83b provided on the mounting table 82a. That is, the position of the mounting table 82a in the X-axis direction can be determined using the laser interferometer 83d attached on the surface plate 81 so as to face the X mirror member 83a. Further, the position of the mounting table 82a in the Y-axis direction can be determined by using a laser interferometer 83e attached to the surface plate 81 side so as to face the Y mirror member 83b.

  The X-axis laser interferometer 83d includes a laser light source 83f that generates the laser light LL, an interference optical system and a sensor (not shown), and the phase of the laser light LL reflected by the mirror surface of the X mirror member 83a. Based on the change, the amount of displacement of the X mirror member 83a in the X-axis direction can be calculated. That is, the laser interferometer 83d and the X mirror member 83a serve as auxiliary measurement means for detecting the X displacement of the measurement jig HD. The laser interferometer 83d operates under the control of the control device 99, and the measurement signal of the laser interferometer 83d is output to the control device 99 in real time, and the operation of the X drive device 50 is monitored. Here, the first tube portion S11 is fixed to the laser interferometer 83d side, and the second tube portion S12 is fixed to the X mirror member 83a side. Both cylinder parts S11 and S12 are coaxially arranged in a double manner, and can expand and contract in the X-axis direction, that is, in the axial direction without interfering with each other. That is, both cylinder parts S11 and S12 serve as shielding means for covering the optical path from the laser interferometer 83d to the X mirror member 83a. By providing such cylindrical portions S11 and S12, generation of measurement noise can be prevented when detecting the laser beam LL, and detection accuracy by the laser interferometer 83d can be increased. Note that the lengths of both the cylindrical portions S11 and S12 are substantially equal to each other and are equal to or greater than the stroke amount of the X drive device 50, that is, the maximum movement amount of the movable portion 52 and the mounting table 82a. Thereby, the optical path of the laser beam LL can always be covered by both the cylindrical portions S11 and S12 while ensuring the movement of the mounting table 82a in the X direction.

  The Y-axis laser interferometer 83e includes a laser light source 83g that generates the laser light LL, an interference optical system and a sensor (not shown), and the phase of the laser light LL reflected by the mirror surface of the Y mirror member 83b. Based on the change, the amount of displacement of the X mirror member 83b in the Y-axis direction can be calculated. That is, the laser interferometer 83e and the Y mirror member 83b serve as auxiliary measuring means for detecting the Y displacement of the measuring jig HD. The laser interferometer 83e operates under the control of the control device 99, and the measurement signal of the laser interferometer 83e is output to the control device 99 in real time, and the operation of the Y drive device 60 is monitored. Here, the first cylindrical portion S21 is fixed on the laser interferometer 83e side, and the second cylindrical portion S22 is fixed on the Y mirror member 83b side. Both cylinder parts S21, S22 are coaxially arranged as a double as a shielding means, and can expand and contract in the X-axis direction, that is, the axial direction without interfering with each other. By providing such cylindrical portions S21 and S22, generation of measurement noise can be prevented when detecting the laser beam LL, and detection accuracy by the laser interferometer 83e can be increased. Note that the lengths of both the cylindrical portions S21 and S22 are substantially equal to each other and are equal to or greater than the stroke amount of the Y drive device 60, that is, the maximum movement amount of the movable portion 62 and the mounting table 82a. Thereby, the optical path of the laser beam LL can always be covered by both the cylindrical portions S21 and S22 while securing the movement of the mounting table 82a in the Y direction.

  The Z drive device 84 has a lifting mechanism 86 fixed on a frame 85. The lifting mechanism 86 is fixed to the upper portion of the frame 85 and extends in the Z direction, and is supported by the support shaft 86a to be in the Z axis direction. And an elevating member 86b that moves up and down, an elevating drive device 86c that elevates and lowers the elevating member 86b, and a probe device 10 supported by the elevating member 86b. Here, the support shaft 86a and the elevating member 86b function as a support device that supports the probe device 10 so as to be displaceable in the Z-axis direction.

  In the elevating mechanism 86, the elevating drive device 86c is a linear motor including a coil stator CS fixed to the support shaft 86a side and a magnet mover MM fixed to the elevating member 86b side. Thereby, the elevating member 86b is supported by the support shaft 86a and moves up and down smoothly. The probe device 10 is a support device and includes a bearing portion 89a that allows the stylus 11 to move up and down with a predetermined force while maintaining the stylus 11 in a substantially balanced state. The bearing portion 89a is a hydrostatic bearing using air, and the stylus 11 is supported in a non-contact manner by the elevating member 86b and smoothly moves up and down. Further, the lift drive device 86c moves the probe device 10 up and down together with the lift member 86b while applying feedback based on the detection result of a differential sensor (not shown) built in the probe device 10. Thereby, the stylus 11 can be raised and lowered over a wide range in a state where a constant low load is applied to the tip of the stylus 11.

  The vertical position of the stylus 11 provided in the probe device 10 is obtained by using a Z mirror member 91a which is provided at the upper end of the stylus 11 and moves up and down together with the stylus 11 and a laser interferometer 91b fixed to the frame 85 side. Detected. Here, the Z mirror member 91a and the laser interferometer 91b function as displacement measuring means for measuring the displacement amount of the stylus 11 in the Z-axis direction, that is, movement amount measuring means.

  Although not described in detail, the laser interferometer 91b for the Z axis includes a laser light source that generates the laser light LL ′, an interference optical system and a sensor, and the laser light reflected by the mirror surface of the Z mirror member 91a. The displacement amount of the Z mirror member 91a in the Z-axis direction, that is, the displacement of the lower end of the stylus 11 can be calculated based on the phase change of LL ′. The laser interferometer 91b operates under the control of the control device 99, and the measurement signal of the laser interferometer 91b is output to the control device 99 in real time, and the operation of the lifting mechanism 86 is monitored.

  In the shape measuring apparatus 100 described above, the XY stage device 82 is appropriately operated while the stylus 11 is moved up and down while the tip of the stylus 11 is placed at a certain load on the surface of the optical element OE. Then, the optical element OE on which the measuring jig HD is placed is moved so as to scan two-dimensionally in the XY plane. Thereby, the tip of the stylus 11 can be moved two-dimensionally along the optical surface of the optical element OE placed on the measurement jig HD. That is, the control device 99 associates the XY coordinates of the mounting table 82a obtained using the laser interferometers 83d and 83e with the Z coordinate of the stylus 11 obtained using the laser interferometer 91b. By performing the arithmetic processing, the three-dimensional surface shape of the optical surface of the optical element OE can be measured.

  At this time, in the shape measuring apparatus 100, the X driving device 50 provided in the XY stage device 82 supports the movable portion 52 in a non-contact manner by air slide and drives the movable portion 52 by the linear motors 51a and 51b. The movement of the 82a in the XY axis directions is smooth and highly accurate. Therefore, when the optical element OE is moved in the XY plane, a minute displacement in the Z-axis direction is less likely to occur, the displacement amount of the stylus 11 can be accurately measured, and the surface shape measurement accuracy of the optical element OE can be increased. Can be improved. Specifically, the Z-direction vibration component when the measurement was performed with a conventional XY stage using a ball screw or an LM guide was 100 nm, whereas the XY stage apparatus 82 of the present embodiment performed the same measurement. The result was that the Z-direction vibration component in this case was improved to 50 nm.

  As described above, the present invention has been described according to the embodiment, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the optical surface of the optical element OE is measured by the shape measuring apparatus 100. However, the surface shape can be measured for various objects to be measured without being limited to the optical element OE.

(A), (b) is the front view and side view explaining the structure of the shape measuring apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Probe apparatus, 11 ... Stylus, 50 ... Drive apparatus, 51 ... Fixed side support part, 51a, 51b ... Linear motor, 51b ... Magnet part, 51g ... Air slide discharge port, 51g, 61g ... Air slide discharge port, 52 ... Movable part 52,62 ... Movable part 60 ... Drive device 61 ... Fixed side support part 61a ... Coil part 61b ... Magnet part 81 ... Surface plate 82 ... Stage device 82a ... Place table 83a , 83b ... Mirror member, 83d, 83e ... Laser interferometer, 84 ... Driving device, 86 ... Lifting mechanism, 86b ... Lifting member, 86c ... Lifting drive device, 91a ... Mirror member, 91b ... Laser interferometer, 98 ... Drive control 99: Control device, 100: Shape measuring device, HD: Measuring jig, LL: Laser light, LM1, LM2: Lock member, OE: Optical element , S11, S12 ... tube portion

Claims (9)

An optical element having a maximum dimension of 50 mm or less as an object to be measured, which can be placed on the upper surface side, and a stage that can move in the X and Y directions extending perpendicular to each other in the horizontal direction;
A stylus that is fixedly arranged with respect to the X direction and the Y direction, is capable of contacting the surface of the object to be measured, and is movable in the Z direction perpendicular to the X direction and the Y direction;
By measuring the amount of movement of the stylus in contact with the object to be measured in the Z direction by moving the object to be measured placed on the mounting table two-dimensionally in the horizontal direction, A movement amount measuring means for obtaining a corresponding Z position from the Z measurement value ;
In the shape measuring device having
The driving means for two-dimensionally moving the mounting table in the horizontal direction includes a guide unit that guides the mounting table in the horizontal direction while supporting the mounting table in a non-contact manner. Linear motors that include two guide mechanisms that guide the table in the X direction and the Y direction that extend orthogonally to each other, and that each of the two guide mechanisms applies a driving force in the respective directions in a non-contact state. If, it possesses an air slide,
The guide section has the two guide mechanisms in two upper and lower stages, and the upper guide mechanism of the two guide mechanisms has a stroke amount equal to or larger than the size of the object to be measured, and the lower guide mechanism. A shape measuring device that realizes a stroke amount equal to or less than that of the above.   The shape measuring apparatus according to claim 1, wherein a holder for holding an object to be measured is provided on the mounting table. The shape measuring apparatus according to claim 1, further comprising a lock unit that locks the guide unit and locks the mounting table. The shape measuring apparatus according to claim 3 , wherein the locking means operates at the time of emergency stop of measurement and when the object to be measured is attached or detached. The shape measuring apparatus according to any one of claims 1 to 4 , wherein the relatively displaceable movable portion provided in the guide portion is formed of a ceramic material. The mounting table related to the horizontal direction that is the predetermined direction based on the return light from the mirror, and a mirror provided on the mounting table and a laser light source that emits laser light for length measurement to the mirror The shape measuring device according to any one of claims 1 to 5 , further comprising auxiliary measuring means for detecting a displacement of the laser beam, wherein the laser light source and the mirror are arranged at a height position corresponding to the stylus. . The apparatus further comprises shielding means having a double cylindrical portion that covers an optical path from the laser light source to the mirror and allows axial expansion and contraction, and the length of each cylindrical portion is determined by the driving means. The shape measuring apparatus according to claim 6 , wherein the shape measuring apparatus is greater than or equal to a stroke amount. The shape measuring apparatus according to claim 1 , wherein the linear motor has a magnet part, and the magnet part is fixed to a movable part side of the guide part.   An optical element having a maximum dimension of 50 mm or less as an object to be measured can be placed on the upper surface side, and is placed with respect to the X direction and the Y direction, which is movable in the X direction and the Y direction, and extends in the horizontal direction. The shape measuring method of the optical element using the shape measuring device provided with a stylus disposed on the surface of the object to be measured and movable in the Z direction perpendicular to the X direction and the Y direction Because
  The driving means for two-dimensionally moving the mounting table in the horizontal direction includes a guide unit that guides the mounting table in the horizontal direction while supporting the mounting table in a non-contact manner. Linear motors that include two guide mechanisms that guide the table in the X direction and the Y direction that extend orthogonally to each other, and that each of the two guide mechanisms applies a driving force in the respective directions in a non-contact state. And an air slide,
  The guide section has the two guide mechanisms in two upper and lower stages, and the upper guide mechanism of the two guide mechanisms has a stroke amount equal to or larger than the size of the object to be measured, and the lower guide mechanism. Compared to
  An optical element having a maximum dimension of 50 mm or less is placed on the mounting table as an object to be measured, and the driving device is driven by the driving unit to move the optical element two-dimensionally in the horizontal direction, A shape measuring method, wherein a corresponding Z position is obtained from a single Z measurement value by measuring an amount of movement of the stylus in contact with an optical element in the Z direction.

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