JPWO2012063551A1 - Optical member attitude adjustment mechanism, Michelson interferometer, and Fourier transform spectroscopic analyzer - Google Patents

Abstract

An optical member posture adjusting mechanism for swinging an optical surface of an optical member in a predetermined direction by swinging it with a predetermined center point as a fulcrum, and extending and contracting in an axial direction when a predetermined voltage is applied. An electromechanical transducer having one end fixed, a drive shaft provided on the other end of the electromechanical transducer and moving in the axial direction by expansion and contraction of the electromechanical transducer, and a predetermined center point as a fulcrum Supporting means for swingably supporting the optical member, and the supporting means is located on the outer peripheral side of the optical member away from a predetermined center point, and includes a moving piece that frictionally engages with the drive shaft. The piece moves forward and backward with the drive shaft when the electromechanical conversion element slowly expands and contracts, and slides with respect to the drive shaft when the electromechanical conversion element expands and contracts steeply. The outer peripheral side moves the moving piece back and forth. It is adjusted by advance and retreat in the axial direction by the fine sliding movement.

Description

  The present invention relates to an attitude adjustment mechanism for an optical member for directing the optical surface of the optical member in a predetermined direction, a Michelson interferometer including the attitude adjustment mechanism for the optical member, and a Fourier transform including the Michelson interferometer. The present invention relates to a spectroscopic analyzer.

  The optical member has an optical surface that receives light. The optical member is, for example, a lens, a prism, or a mirror, and collects (guides), reflects, or transmits light received on the optical surface. The material of the optical member is, for example, resin, glass, metal, or metal thin film. The attitude adjustment mechanism of the optical member can be used in a Michelson interferometer incorporated in a Fourier Transform Infrared Spectroscopy (FTIR). In this case, the posture adjustment mechanism of the optical member adjusts the posture of the fixed mirror as the optical member.

  JP, 2002-148116, A (patent documents 1) is known as an invention about a posture adjustment mechanism of an optical member. This document discloses an interference spectrophotometer capable of automatically performing coarse adjustment and fine adjustment of the posture of the fixed mirror. The posture adjustment mechanism of the optical member in the document includes a piezoelectric element and a piezoelectric element moving unit that moves the piezoelectric element.

  The piezoelectric element moving means in the above document (Patent Document 1) includes a motor and a motion conversion mechanism (such as a gear, a cylindrical body, and a screw hole) that converts the rotational power of the motor into a linear motion. The piezoelectric element is reciprocated linearly by the motor and the motion conversion mechanism. The posture of the fixed mirror is adjusted by the linear reciprocation of the piezoelectric element. However, the fixed mirror (optical member) posture adjustment mechanism in this document has a large number of parts and a complicated structure.

JP 2002-148116 A

  The present invention has a simple configuration, an optical member attitude adjustment mechanism for directing the optical surface of an optical member in a predetermined direction, a Michelson interferometer including the optical member attitude adjustment mechanism, and the Michelson interference It is an object of the present invention to provide a Fourier transform spectroscopic analyzer equipped with a meter.

  An optical member posture adjusting mechanism according to the present invention is an optical member posture adjusting mechanism for turning an optical surface of an optical member in a predetermined direction by swinging the optical surface about a predetermined center point. Is applied to the electromechanical transducer having one end fixed, and the other end of the electromechanical transducer is provided. A drive shaft that moves forward and backward in a direction, and a support means that swingably supports the optical member with the predetermined center point as a fulcrum, wherein the support means is separated from the predetermined center point. A moving piece that is frictionally engaged with the drive shaft, and the moving piece moves forward and backward together with the drive shaft when the electromechanical conversion element expands and contracts slowly, and the electric machine Conversion element When it expands and contracts steeply, it slides with respect to the drive shaft, and the attitude of the optical member is adjusted by moving the outer peripheral side of the optical member forward and backward in the axial direction by the forward and backward movement and sliding movement of the moving piece. Is done.

  According to the present invention, an optical member attitude adjusting mechanism for directing an optical surface of an optical member in a predetermined direction, a Michelson interferometer including the optical member attitude adjusting mechanism, and the Michael having a simple configuration, and the Michael A Fourier transform spectroscopic analyzer equipped with a Son interferometer can be obtained.

It is a figure which shows typically the structure of the Fourier-transform spectroscopy analyzer in embodiment. It is a front view which shows the structure of the reference detector used for the Michelson interferometer in embodiment. (A) is a figure which shows the time-dependent change of the intensity | strength of a part of interference light which the reference detector used for the Michelson interferometer in embodiment detects. (B) is a figure which shows the time-dependent change of the intensity | strength of the remainder of the interference light which the reference detector used for the Michelson interferometer in embodiment detected. It is a 1st disassembled perspective view which shows the attitude | position adjustment mechanism of the optical member in embodiment. It is arrow sectional drawing regarding the VV line in FIG. It is a 2nd disassembled perspective view which shows the upper side of the attitude | position adjustment mechanism of the optical member in embodiment. It is a 3rd disassembled perspective view which shows the downward side of the attitude | position adjustment mechanism of the optical member in embodiment. It is a figure which shows the waveform of the voltage applied to the piezoelectric element used for the attitude | position adjustment mechanism of the optical member in embodiment. (A) is sectional drawing which shows the mode before the coarse adjustment of the moving piece used for the attitude | position adjustment mechanism of the optical member in embodiment. (B) is sectional drawing which shows the mode after the coarse adjustment of the moving piece used for the attitude | position adjustment mechanism of the optical member in embodiment. (C) is sectional drawing which shows the mode after the fine adjustment of the moving piece used for the attitude | position adjustment mechanism of the optical member in embodiment. It is sectional drawing which shows a mode that the attitude | position of a fixed mirror is adjusted with the attitude | position adjustment mechanism of the optical member in embodiment. It is a figure which shows the waveform of the other voltage applied to the piezoelectric element used for the attitude | position adjustment mechanism of the optical member in embodiment. It is sectional drawing which shows the attitude | position adjustment mechanism of the optical member in the other structure of embodiment.

  Embodiments based on the present invention will be described below with reference to the drawings. In the description of the embodiments, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, or the like unless otherwise specified. In the description of the embodiments, the same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated.

(Fourier transform spectrometer 1000 / Michelson interferometer 110)
With reference to FIG. 1, a Fourier transform spectroscopic analyzer 1000 according to the embodiment will be described. The Fourier transform spectroscopic analysis apparatus 1000 includes a Michelson interferometer 110, a calculation unit 120, and an output unit 130. The Michelson interferometer 110 includes a spectroscopic optical system 111, a reference optical system 121, and an optical member attitude adjustment mechanism 100.

(Spectroscopic optical system 111)
The spectroscopic optical system 111 includes a light source 112, a collimating optical system 113, a beam splitter 114, a fixed mirror 115, a moving mirror 116, a condensing optical system 117, a detector 118, and a driving mechanism 119.

  The light source 112 is composed of a light emitting element such as a semiconductor laser, and emits light such as infrared light. The light emitted from the light source 112 is introduced into an optical path combining mirror 123 in the reference optical system 121 (details will be described later), and is combined with the light emitted from the reference light source 122 (details will be described later). The combined light is emitted from the optical path combining mirror 123, converted into parallel light by the collimating optical system 113, and then introduced into the beam splitter 114. The beam splitter 114 is composed of a half mirror or the like. The light (incident light) introduced into the beam splitter 114 is divided into two light beams.

  One of the divided lights is applied to the fixed mirror 115. The light (reflected light) reflected by the surface 115A (optical surface) of the fixed mirror 115 passes through substantially the same optical path as before the reflection, and is irradiated again to the beam splitter 114. The other of the divided lights is irradiated on the movable mirror 116. The light (reflected light) reflected by the surface 116A (optical surface) of the movable mirror 116 passes through substantially the same optical path as before the reflection, and is irradiated again to the beam splitter 114. The reflected light from the fixed mirror 115 and the reflected light from the moving mirror 116 are combined (superposed) by the beam splitter 114.

  Here, when the other of the divided lights is reflected by the surface 116A of the movable mirror 116, the movable mirror 116 is reciprocated in the direction of the arrow AR116 while being kept parallel by the drive mechanism 119. Due to the reciprocating movement of the movable mirror 116, a difference in optical path length occurs between the reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116. The reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116 are combined by the beam splitter 114 to form interference light.

  Depending on the position of the movable mirror 116, the difference in optical path length changes continuously. The intensity of light as interference light also changes continuously according to the difference in optical path length. When the difference in optical path length is, for example, an integral multiple of the wavelength of light irradiated from the collimating optical system 113 to the beam splitter 114, the intensity of light as interference light is maximized.

  The sample S is irradiated with the light forming the interference light. The light transmitted through the sample S is condensed on the condensing optical system 117. The condensed light is introduced into the optical path separation mirror 124 in the reference optical system 121 (details will be described later). The detector 118 detects the light emitted from the optical path separation mirror 124 as an interference pattern (interferogram). This interference pattern is sent to a calculation unit 120 including a CPU (Central Processing Unit) and the like. The computing unit 120 converts the collected (sampled) interference pattern from an analog format to a digital format, and further performs a Fourier transform on the converted data.

  A spectral distribution indicating the light intensity for each wave number (= 1 / wavelength) of light (interference light) transmitted through the sample S is calculated by Fourier transform. The data after the Fourier transform is output to another device through the output unit 130 or displayed on a display or the like. Based on this spectral distribution, the characteristics (eg, material, structure, or amount of components) of the sample S are analyzed.

(Reference optical system 121)
The reference optical system 121 includes a collimating optical system 113, a beam splitter 114, a fixed mirror 115, a moving mirror 116, a condensing optical system 117, a reference light source 122, an optical path synthesis mirror 123, an optical path separation mirror 124, a reference detector 125, and a signal. A processing unit 126 is included. The collimating optical system 113, the beam splitter 114, the fixed mirror 115, the moving mirror 116, and the condensing optical system 117 are common to both the spectroscopic optical system 111 and the reference optical system 121.

  The reference light source 122 is composed of a light emitting element such as a semiconductor laser, and emits light such as red light. As described above, the light emitted from the reference light source 122 is introduced into the optical path combining mirror 123. The optical path combining mirror 123 is composed of a half mirror or the like. The light from the light source 112 passes through the optical path combining mirror 123. The light from the reference light source 122 is reflected by the optical path combining mirror 123.

  The light from the light source 112 and the light from the reference light source 122 are emitted from the optical path combining mirror 123 onto the same optical path in a state where they are combined by the optical path combining mirror 123. The light emitted from the optical path combining mirror 123 is converted into parallel light by the collimating optical system 113 and then introduced into the beam splitter 114 and split into two light beams.

  As described above, one of the divided lights is applied to the fixed mirror 115 and is applied again to the beam splitter 114 as reflected light. The other of the divided lights is applied to the movable mirror 116 and is applied again to the beam splitter 114 as reflected light. The reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116 are combined by the beam splitter 114 to form interference light.

  As described above, the sample S is irradiated with the light forming the interference light. The light transmitted through the sample S is condensed on the condensing optical system 117. The condensed light is introduced into the optical path separation mirror 124 in the reference optical system 121. The optical path separation mirror 124 is composed of a half mirror or the like, and the light (incident light) introduced into the optical path separation mirror 124 is divided into two light beams.

  The light emitted from the light source 112 and introduced into the optical path separation mirror 124 through the optical path synthesis mirror 123, the collimating optical system 113, the beam splitter 114, the fixed mirror 115, the moving mirror 116, the sample S, and the condensing optical system 117 is an optical path. The light passes through the separation mirror 124. As described above, this light (interference light) transmitted through the optical path separation mirror 124 is detected by the detector 118.

  On the other hand, light emitted from the reference light source 122 and introduced into the optical path separation mirror 124 through the optical path synthesis mirror 123, the collimating optical system 113, the beam splitter 114, the fixed mirror 115, the moving mirror 116, the sample S, and the condensing optical system 117. Is reflected by the optical path separation mirror 124. Reflected light (interference light) from the optical path separation mirror 124 is detected as an interference pattern by a reference detector 125 constituted by a quadrant sensor or the like.

  The interference pattern of the interference light is sent to a signal processing unit 126 including a CPU and the like. The signal processing unit 126 calculates the intensity of the reflected light from the optical path separation mirror 124 based on the collected interference pattern. The signal processing unit 126 can generate a signal indicating the sampling timing in the calculation unit 120 based on the intensity of the reflected light from the optical path separation mirror 124. A signal indicating the sampling timing in the arithmetic unit 120 can be generated by a known means.

  Based on the intensity of the reflected light from the optical path separation mirror 124, the signal processing unit 126 tilts the light between the two optical paths (relative tilt between the reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116). Can also be calculated. For example, the inclination of light between the two optical paths is calculated as follows.

  With reference to FIG. 2, the reference detector 125 comprised of a four-divided sensor has four light receiving areas E1 to E4. The light receiving areas E1 to E4 are adjacent to each other in a counterclockwise direction. Reflected light from the optical path separation mirror 124 is irradiated to the area constituted by the light receiving areas E1 to E4. The center of the region constituted by the light receiving regions E1 to E4 and the center of the spot D of the reflected light from the optical path separation mirror 124 are substantially coincident.

  The light receiving areas E1 to E4 detect the intensity of the reflected light applied to each area from the optical path separation mirror 124. The intensity of the reflected light from the optical path separation mirror 124 is detected as a phase signal that changes with time, for example, as shown in FIGS. 3 (A) and 3 (B).

  Each horizontal axis of FIG. 3 (A) and FIG. 3 (B) indicates the passage of time (unit: second). The vertical axis of FIG. 3A indicates the sum of the light intensity detected by the light receiving area E1 and the light intensity detected by the light receiving area E2 as intensity A1 (relative value). The vertical axis in FIG. 3B indicates the sum of the light intensity detected by the light receiving area E3 and the light intensity detected by the light receiving area E4 as intensity A2 (relative value).

  As shown in FIGS. 3A and 3B, when there is an inclination of light between the two optical paths (relative inclination between the reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116). A phase difference Δ occurs between the intensity A1 and the intensity A2. That is, based on the phase difference Δ, the light inclination between the two optical paths can be calculated. Other phase differences Δ can be obtained by other combinations of the light receiving areas E1 to E4 (for example, combinations of the light receiving areas E1 and E4 and the light receiving areas E2 and E3). Based on the above phase difference Δ and other phase differences Δ, the direction (vector) of the inclination of light between the two optical paths can also be calculated.

(Optical member attitude adjustment mechanism 100)
Referring to FIG. 1 again, the optical member attitude adjusting mechanism 100 is based on the detection result in the signal processing unit 126 (relative inclination between the reflected light from the fixed mirror 115 and the reflected light from the movable mirror 116). The attitude of the fixed mirror 115 (angle with respect to the beam splitter 114) is adjusted in the direction of the arrow AR115. By this adjustment, the optical path of the reflected light at the fixed mirror 115 is corrected, and the inclination of the light between the two optical paths can be eliminated (or reduced). By providing the optical member attitude adjusting mechanism 100 in the Michelson interferometer 110, it becomes possible to generate interference light with higher accuracy.

  The configuration of the optical member attitude adjustment mechanism 100 (hereinafter also referred to as the attitude adjustment mechanism 100) will be described in detail below with reference to FIGS.

  FIG. 4 is a first exploded perspective view of the posture adjustment mechanism 100. For convenience, in FIG. 4, a part of an intermediate body 60 described later (a portion indicated by hatching) is broken and illustrated. Actually, as shown in FIG. 6, the part of the intermediate body 60 is not broken. FIG. 5 is a cross-sectional view taken along the line VV in FIG. In FIG. 5, the attitude adjustment mechanism 100 is disassembled and is not shown. FIG. 6 is a second exploded perspective view of the posture adjustment mechanism 100. In FIG. 6, the upper side of the posture adjustment mechanism 100 is shown. FIG. 7 is a third exploded perspective view of the posture adjustment mechanism 100. In FIG. 7, the lower side of the attitude adjustment mechanism 100 is shown.

  4 to 7 (mainly FIG. 6), the posture adjustment mechanism 100 includes an upper body 10, bolts 21 to 24, a pedestal 30, moving pieces 40 and 41, a sphere 50 (pedestal support member), and an intermediate body 60. Drive shafts 70 and 71, piezoelectric elements 80 and 81 as electromechanical transducers, and a lower body 90. The pedestal 30, the moving pieces 40 and 41, and the sphere 50 (pedestal support member) function as support means.

  The upper body 10 is formed in a flat plate shape. The thickness of the upper body 10 is, for example, 1.0 mm. The upper body 10 has through holes 11 to 13 on the outer peripheral side, a through hole 16 in the approximate center, and through holes 14 and 15 outside the through hole 16. When viewed from the center of the through-hole 16, the through-holes 14 and 15 are spaced from each other by 90 °. Bolts 21 to 23 are respectively inserted into the through holes 11 to 13 (see FIG. 4). The bolts 21 to 23 are respectively screwed into screw holes 61 to 63 provided in an intermediate body 60 described later. The upper body 10 and the intermediate body 60 are joined to each other by screwing the bolts 21 to 23 and the screw holes 61 to 63.

  The diameter of the through hole 16 is, for example, 6.0 mm, which is slightly larger than the diameter of the fixed mirror 115 that is formed in a disk shape as an optical member. In the state in which the posture adjusting mechanism 100 is assembled, the fixed mirror 115 is positioned in the through hole 16 (see FIGS. 4 and 5). The surface 115 </ b> A of the fixed mirror 115 is exposed from the through hole 16. Upper ends of drive shafts 70 and 71, which will be described later, are inserted into the through holes 14 and 15, respectively (see FIG. 5). The diameter of the through holes 14 and 15 is, for example, 1.0 mm, and the diameter of the drive shafts 70 and 71 is, for example, 1.0 mm.

  The pedestal 30 is formed in a disk shape. The pedestal 30 has a front surface 30A and a back surface 30B. The diameter of the pedestal 30 is, for example, 8.5 mm, and is larger than the diameter of the fixed mirror 115 disposed on the surface 30A. The fixed mirror 115 is arranged coaxially with the pedestal 30. An annular convex portion 32 (see FIGS. 5 and 7) is provided on the back surface 30B of the base 30. The spherical body 50 is disposed so as to come into contact with the back surface 30B in the annular convex portion 32. The entire surface of the sphere 50 is formed in a spherical shape. The diameter of the sphere 50 is, for example, 3.0 mm.

  Referring to FIG. 5, the fixed mirror 115 and the sphere 50 may each be composed of a magnetic body that generates a magnetic force in a direction attracting each other. Specifically, for example, one of the sphere 50 and the fixed mirror 115 is composed of a magnet (an example of a magnetic body), and the other of the sphere 50 and the fixed mirror 115 is composed of a metal (another example of a magnetic body). When the magnetic force is generated in the direction attracting each other, both the fixed mirror 115 and the sphere 50 may be composed of magnets.

  The sphere 50 and the fixed mirror 115 are attracted to each other by the action of magnetic force. In a state where the posture adjustment mechanism 100 is assembled, the contact state (bonded state) between the front surface 30A of the base 30 and the back surface 115B of the fixed mirror 115 is maintained by the action of the magnetic force. Since the fixed mirror 115 is not bonded (fixed) to the pedestal 30, it can be easily replaced. The contact state (bonded state) between the back surface 30B of the base 30 and the sphere 50 is also maintained by the action of the magnetic force.

  Since the base 30 is always in contact with the sphere 50, the pedestal 30 can swing on the sphere 50. When the pedestal 30 swings on the sphere 50, since the sphere 50 is pressed against the pedestal 30 by the action of magnetic force, the contact portion 52 between the back surface 30 </ b> B of the pedestal 30 that is the fulcrum of the pedestal 30 and the sphere 50. Can move smoothly in accordance with the swing of the pedestal 30.

  In the state where the posture adjustment mechanism 100 is assembled, the sphere 50 is joined to the intermediate body 60. For example, when the intermediate body 60 and the sphere 50 are magnetic bodies that generate a magnetic force in a direction that attracts each other, the sphere 50 is bonded to the intermediate body 60. The joining state of the sphere 50 and the intermediate body 60 is maintained by the action of the magnetic force. For example, one of the sphere 50 and the intermediate body 60 may be composed of a magnet, and the other of the sphere 50 and the intermediate body 60 may be composed of a metal.

  The sphere 50 may be fitted to the upper opening end 66A (details will be described later) of the intermediate body 60, or may be bonded to the upper opening end 66A. The spherical body 50 may be clamped and fixed to the upper opening end 66A of the intermediate body 60, or the spherical body 50 may be fixed to the intermediate body 60 by means such as screwing.

  By joining the sphere 50 to the intermediate body 60, the pedestal 30 can swing on the surface of the sphere 50 while being separated from the upper body 10 and the intermediate body 60. In other words, the pedestal 30 can swing on the surface of the sphere 50 without contacting the upper body 10 and the intermediate body 60. Along with the swing, the fixed mirror 115 disposed on the pedestal 30 also swings. By providing the annular protrusion 32 on the back surface 30 </ b> B of the pedestal 30, when the pedestal 30 swings on the surface of the sphere 50, excessive displacement of the pedestal 30 with respect to the sphere 50 is prevented.

  Moving pieces 40 and 41 (see FIG. 4) provided for swinging the pedestal 30 are joined to a part of the outer periphery of the pedestal 30. When viewed from the center of the pedestal 30, the movable pieces 40 and 41 are spaced by 90 ° from each other. The moving pieces 40 and 41 have upper clamp portions 44 and 45, cylindrical portions 42 and 43, and lower clamp portions 46 and 47, respectively.

  The base 30 is sandwiched between the upper clamp portions 44 and 45 and the lower clamp portions 46 and 47, respectively. With this configuration, the pedestal 30 is supported at three locations by the sphere 50, the moving piece 40, and the moving piece 41. When the cylindrical portions 42 and 43 are displaced (moved), the pedestal 30 swings while maintaining a contact state with the sphere 50. Drive shafts 70 and 71 described later are fitted into the cylindrical portions 42 and 43, respectively.

  The intermediate body 60 is formed in a flat plate shape. The intermediate body 60 has a front surface 60A and a back surface 60B (see FIG. 7). The thickness of the intermediate body 60 (the distance between the front surface 60A and the back surface 60B) is, for example, 2.7 mm. The intermediate body 60 has a hollow portion 67 in the approximate center of the surface 60A, a circular recess 66 in the bottom surface of the hollow portion 67, screw holes 61 to 63 in the surface 60A, and notches 68 and 69 outward from the hollow portion 67. In addition, through holes 64 and 65 are provided on the bottom surfaces of the notches 68 and 69, and a hanging portion 66M (see FIGS. 5 and 7) is provided on the back surface 60B. The diameter of the through holes 64 and 65 is, for example, 1.0 mm.

  As viewed from the center of the circular recess 66, the through holes 64, 65 are spaced from each other by 90 °. The diameter of the cut-out portion 67 is slightly larger than the diameter of the pedestal 30. In a state in which the posture adjustment mechanism 100 is assembled, the base 30, the moving piece 40, and the moving piece 41 are respectively located in the cutout portion 67, the cutout portion 68, and the cutout portion 69 (see FIGS. 4 and 5). ).

  The sphere 50 is disposed on the upper opening end 66 </ b> A of the circular recess 66. As described above, the sphere 50 may be joined to the intermediate body 60 by an action such as magnetic force. As described above, the sphere 50 may be fitted to the upper opening end 66A of the intermediate body 60, or may be bonded to the upper opening end 66A. The spherical body 50 may be clamped and fixed to the upper opening end 66A of the intermediate body 60, or the spherical body 50 may be fixed to the intermediate body 60 by means such as screwing.

  The positions of the screw holes 61 to 63 correspond to the positions of the through holes 11 to 13 in the upper body 10. As described above, in a state where the posture adjustment mechanism 100 is assembled, the bolts 21 to 23 are screwed into the screw holes 61 to 63, respectively. The upper body 10 and the intermediate body 60 are joined by screwing the bolts 21 to 23 and the screw holes 61 to 63 (see FIG. 5).

  The suspended portion 66M is suspended from the back surface 60B of the intermediate body 60 in a cylindrical shape. Piezoelectric elements 80 and 81, which will be described later, are provided outside the drooping portion 66M (see FIGS. 5 and 7). A nut 66N is provided at the lower end of the hanging part 66M.

  The drive shafts 70 and 71 are cylindrical members. The axial length of the drive shafts 70 and 71 is, for example, 4.0 mm. The drive shafts 70 and 71 are respectively provided at the other end portions 84 and 85 of the piezoelectric elements 80 and 81 (expandable portions 82 and 83) whose one end portions 86 and 87 are fixed to the bases 88 and 89, respectively. In a state in which the posture adjustment mechanism 100 is assembled, the drive shafts 70 and 71 include the through holes 64 and 65 of the intermediate body 60, the cylindrical portions 42 and 43 of the moving pieces 40 and 41, and the through holes 14 of the upper body 10. 15 are inserted in order (see FIG. 5). The drive shafts 70 and 71 are frictionally engaged with the cylindrical portions 42 and 43 with a predetermined friction force, respectively.

  The moving pieces 40 and 41 (cylindrical portions 42 and 43) are configured to be slidable with respect to the drive shafts 70 and 71, respectively. Specifically, when a predetermined voltage is applied to the piezoelectric elements 80 and 81, the piezoelectric elements 80 and 81 expand and contract, respectively. When the drive shafts 70 and 71 slowly move forward and backward due to the expansion and contraction of the piezoelectric elements 80 and 81, the moving pieces 40 and 41 move forward and backward together with the drive shafts 70 and 71, respectively. When the drive shafts 70 and 71 move forward and backward steeply due to the expansion and contraction of the piezoelectric elements 80 and 81, the moving pieces 40 and 41 slide relative to the drive shafts 70 and 71, respectively.

  The piezoelectric elements 80 and 81 have expansion and contraction portions 82 and 83 connected to a voltage control circuit (not shown), respectively. The length (initial length) of the expansion / contraction portions 82 and 83 of the piezoelectric elements 80 and 81 is, for example, 9.0 mm. The extendable parts 82 and 83 are constituted by a large number of stacked piezoelectric plates, and a predetermined voltage independent from the voltage control circuit is applied thereto. The extendable parts 82 and 83 expand and contract in the axial direction (see arrows AR82 and AR83 in FIG. 4) when a predetermined voltage is applied.

  As described above, the drive shafts 70 and 71 are provided on the other end portions 84 and 85 of the telescopic portions 82 and 83, respectively. As the telescopic portions 82 and 83 expand and contract, the drive shafts 70 and 71 move forward and backward along the telescopic direction of the telescopic portions 82 and 83, respectively.

  Bases 88 and 89 are provided at one end portions 86 and 87 of the telescopic portions 82 and 83, respectively. In the state where the posture adjustment mechanism 100 is assembled, the bases 88 and 89 are respectively fixed on the lower body 90 (see FIG. 5). With this configuration, the other end portions 84 and 85 of the expansion and contraction portions 82 and 83 constitute the free ends of expansion and contraction as the piezoelectric elements 80 and 81, respectively. The one end portions 86 and 87 of the expansion and contraction portions 82 and 83 constitute the expansion and contraction fixed ends of the piezoelectric elements 80 and 81, respectively.

  The lower body 90 is formed in a flat plate shape. A convex portion 91 is provided at a substantially central portion of the lower body 90. A through hole 92 is provided at the center of the convex portion 91. In the state where the posture adjusting mechanism 100 is assembled, the bolt 24 is fitted into the through hole 92, and the bolt 24 is screwed into the nut 66N (see FIG. 5). The lower body 90 and the intermediate body 60 are joined by screwing the bolt 24 and the nut 66N.

  The Fourier transform spectroscopic analyzer 1000, the Michelson interferometer 110, and the optical member attitude adjustment mechanism 100 are configured as described above.

(Operation of Fourier transform spectroscopic analyzer 1000 etc.)
The Fourier transform spectroscopic analyzer 1000 is installed in a predetermined place such as a laboratory or a development room. After the Fourier transform spectroscopic analysis apparatus 1000 is installed, the posture of the fixed mirror 115 is adjusted. The posture of the fixed mirror 115 is adjusted by the posture adjustment mechanism 100 described above.

  Further, as described above with reference to FIGS. 3A and 3B, the posture adjustment mechanism 100 detects the detection result (the reflected light from the fixed mirror 115 and the movement) in the signal processing unit 126 (see FIG. 1). The attitude of the fixed mirror 115 (angle with respect to the beam splitter 114) is adjusted based on the relative inclination with the reflected light from the mirror 116. By this adjustment, the optical path of the reflected light at the fixed mirror 115 is corrected, and the inclination of the light between the two optical paths can be eliminated (or reduced). The interference light can be generated with higher accuracy.

  Hereinafter, the operation of the posture adjustment mechanism 100 for adjusting the posture of the fixed mirror 115 will be described in detail with reference to FIGS. The posture of the fixed mirror 115 is first roughly adjusted (hereinafter referred to as coarse adjustment), and then finely adjusted as necessary (hereinafter referred to as fine adjustment).

  Referring to FIG. 8, at the time of coarse adjustment, a pulse voltage (sawtooth wave) as shown in FIG. 8 (or FIG. 11) is applied to piezoelectric elements 80 and 81 (expandable portions 82 and 83). . Since the piezoelectric element 81 operates in the same manner as the piezoelectric element 80, the operation of the piezoelectric element 80 (expandable portion 82) will be described below as an example.

  When a pulse voltage as shown in FIG. 8 is applied to the expansion / contraction part 82, the expansion / contraction part 82 repeatedly expands and contracts. In each pulse voltage, in the inclined part V1 (upper part) where the voltage applied to the expansion / contraction part 82 increases slowly, the expansion / contraction part 82 extends slowly. In the inclined portion V1, for example, the applied voltage is increased from 0V to 6V over a time of 25 microseconds. Among the pulse voltages, in the falling portion V2 where the voltage applied to the expansion / contraction part 82 sharply decreases, the expansion / contraction part 82 rapidly contracts and then returns to the initial length. In the falling part V2, for example, the applied voltage is reduced from 6V to 0V over a period of 2 microseconds.

  Referring to FIG. 9A, as described above, one end 86 of the stretchable portion 82 is fixed to the base 88 (fixed to the lower body 90), and constitutes a fixed end of stretch. The other end 84 of the expansion / contraction part 82 forms a free end of expansion / contraction. The drive shaft 70 is fixed on the other end portion 84. The drive shaft 70 moves forward and backward together with the other end portion 84.

  When the expansion / contraction part 82 extends slowly, the drive shaft 70 is pressed by the other end part 84 and slowly moves together with the moving piece 40 in the right direction on the paper surface. When the telescopic portion 82 rapidly contracts and returns to the initial length, the drive shaft 70 is pulled by the other end portion 84 and rapidly moves in the left direction of the drawing.

  When the drive shaft 70 moves rapidly to the left in the drawing (when the telescopic part 82 rapidly contracts and returns to the initial length), the moving piece 40, the pedestal 30, and the fixed mirror 115 (see FIG. 5) each depend on their own weight. The frictional engagement state between the drive shaft 70 and the moving piece 40 is released by the action of inertia. The drive shaft 70 slides relative to the moving piece 40. The positions of the moving piece 40, the pedestal 30, and the fixed mirror 115 (see FIG. 5) hardly change, and only the drive shaft 70 moves to the left in the drawing.

  The expansion / contraction part 82 is slowly extended again by applying the voltage of the inclined part V1 (see FIG. 8). Thereafter, the expansion / contraction part 82 rapidly contracts again by the application of the voltage at the lower end V2 (release of the voltage) and returns to the initial length.

  As shown in FIG. 9B, the moving piece 40 gradually moves in the direction of the arrow AR1 by repeating the above operation. The moving piece 40 moves, for example, 100 nm in the same direction by a single pulse voltage applied to the piezoelectric element 80. When the moving piece 40 moves in the same direction by the distance L1 by a plurality of movements, the pedestal 30 (the outer periphery thereof) also moves in the same direction by the distance L1. The extension / contraction part 82 repeats returning to the initial length after extension, so the position of the drive shaft 70 does not change.

  After the moving piece 40 has moved, fine adjustment is performed as necessary. When the moving piece 40 has already reached the desired position, fine adjustment may not be performed. At the time of fine adjustment, a constant voltage (continuous wave) is applied to the expansion / contraction part 82.

  As shown in FIG. 9C, during fine adjustment, the expansion / contraction part 82 slightly extends in the direction of the arrow AR2, and the other end 84 also moves in the same direction by a minute distance. The drive shaft 70 is pressed by the other end portion 84 and moves together with the moving piece 40 in the same direction. When the telescopic part 82 extends by the distance L2, the pedestal 30 (the outer periphery thereof) also moves in the same direction by the distance L2. When a voltage of, for example, 10 V is applied to the piezoelectric element 80, the pedestal 30 moves, for example, by 0.5 μm as the distance L2.

  Referring to FIG. 10, moving piece 40 moves in the direction of arrow AR3 by the above-described rough adjustment (and fine adjustment), and reaches a desired position. As the moving piece 40 moves, the outer periphery of the pedestal 30 also moves. The pedestal 30 rotates in the direction of the arrow AR4 with the contact portion 52 with the sphere 50 as a fulcrum. The fixed mirror 115 joined to the pedestal 30 also rotates in the same direction.

  In the above description, the case where the moving piece 40 is moved in the right direction in FIG. 9 and FIG. 10 has been described. Referring to FIG. 11, when the moving piece 40 is moved in the left direction on the paper surface, a pulse voltage (sawtooth wave) as shown in FIG.

  When a pulse voltage as shown in FIG. 11 is applied to the expansion / contraction part 82, the expansion / contraction part 82 repeatedly expands and contracts. In each pulse voltage, in the inclined part V3 (the lower part) where the voltage applied to the expansion / contraction part 82 decreases slowly, the expansion / contraction part 82 contracts slowly and returns to the initial length. When the expansion / contraction part 82 contracts slowly, the drive shaft 70 moves slowly together with the moving piece 40. Among the pulse voltages, in the rising portion V4 where the voltage applied to the expansion / contraction section 82 increases steeply, the expansion / contraction section 82 expands rapidly. When the expansion / contraction part 82 extends rapidly, the drive shaft 70 slides relative to the moving piece 40. Similarly to the case where a pulse voltage as shown in FIG. 8 is applied to the expansion / contraction part 82, fine adjustment may be performed on the moving piece 40 after coarse adjustment on the moving piece 40.

(Action / Effect)
When the pulse voltage as shown in FIG. 8 or FIG. 11 is applied to the expansion and contraction portions 82 and 83 in the piezoelectric elements 80 and 81, the posture adjustment mechanism 100 of the optical member is moved to the fixed mirror 115 bonded to the pedestal 30. The posture can be roughly adjusted (coarse adjustment). Thereafter, a constant voltage is applied to the expansion and contraction portions 82 and 83 of the piezoelectric elements 80 and 81 as necessary, so that the attitude adjustment mechanism 100 of the optical member finely adjusts the attitude of the fixed mirror 115 bonded to the pedestal 30. Can be adjusted (fine adjustment). By these rough adjustment and fine adjustment, the surface 115A (optical surface) of the fixed mirror 115 can be directed in a desired direction.

  The posture of the fixed mirror 115 (orientation of the surface 115A) may be adjusted after the Fourier transform spectroscopic analysis apparatus 1000 is installed at a predetermined location or when the Fourier transform spectroscopic analysis apparatus 1000 is activated. The posture of the fixed mirror 115 may be adjusted based on the detection result in the signal processing unit 126 when generating interference light. In this case, the interference light can be generated with higher accuracy.

  Unlike the Japanese Unexamined Patent Publication No. 2002-119074 (Patent Document 1) described at the beginning, the posture adjustment mechanism 100 of the optical member in the present embodiment is a motion conversion that converts the rotational power of the motor and the motor into a linear motion. No mechanism (gear, cylinder, screw hole, etc.) is provided. The posture adjustment mechanism 100 for the optical member in the present embodiment can be configured more simply than in the same document.

(Other configurations of the embodiment)
With reference to FIG. 12, another configuration (modification) of the above-described embodiment will be described. In the above-described embodiment, the sphere 50 is used separately from the intermediate body 60 as a pedestal support member constituting the fulcrum of the pedestal 30.

  As shown in FIG. 12, the pedestal support member that constitutes the pivot point of the pedestal 30 may be a convex portion 60 </ b> T configured integrally with the intermediate body 60. A part of the surface of the convex portion 60T (a portion in contact with the back surface 30B of the pedestal 30) is formed in a spherical shape. In this case, the fixed mirror 115 and the intermediate body 60 are each preferably composed of a magnetic body that generates a magnetic force in a direction attracting each other. Also with this configuration, the pedestal 30 can swing around the contact portion 52 with the convex portion 60T, and the same effect as the above-described embodiment can be obtained.

  In the above-described embodiment, the pedestal 30 and the sphere 50 are joined by the action of magnetic force (the contact state is maintained). As shown in FIG. 12, the contact state between the pedestal 30 and the convex portion 60T (which may be the sphere 50) may be maintained by the leaf spring member 60S.

  The leaf spring member 60S is attached to the surface 60A of the intermediate body 60, for example. At the tip of the leaf spring member 60S, a tip protrusion 60U having a spherical surface is provided. The tip convex portion 60U biases the surface 30A of the base 30 in the direction of the arrow AR5. By the biasing, the base 30 is pressed against the convex portion 60T, and the contact state between the base 30 and the convex portion 60T is maintained. Also with this configuration, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the moving pieces 40 and 41 are spaced by 90 °. The moving pieces 40 and 41 may be spaced at intervals of 45 °, 60 °, 120 °, 135 °, and the like, for example. The drive shafts 70 and 71 and the piezoelectric elements 80 and 81 are arranged in accordance with the distance between the moving pieces 40 and 41. Also with this configuration, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the fixed mirror 115 is disposed on the pedestal 30 supported (gripped) by the movable pieces 40 and 41, and is oscillated by the movement of the movable pieces 40 and 41 (oscillation of the pedestal 30). The The pedestal 30 may be used as necessary. When the pedestal 30 is not used, the fixed mirror 115 is directly supported by the movable pieces 40 and 41 at a part (two places) on the outer peripheral side thereof. Also with this configuration, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the pedestal 30 is supported at three locations by the sphere 50, the moving piece 40, and the moving piece 41. With this configuration, the posture of the fixed mirror 115 as an optical member can be adjusted in a three-dimensional direction. As an optical member, the posture may be adjusted only in the two-dimensional direction. In this case, the pedestal 30 may be supported at two locations by the sphere 50 and the moving piece 40. The posture of the pedestal 30 can be adjusted only in the two-dimensional direction by moving the moving piece 40 forward and backward with the contact portion 52 with the sphere 50 as a fulcrum.

  As mentioned above, although embodiment based on this invention was described, embodiment disclosed this time is an illustration and restrictive at no points. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 Upper body, 11-16, 64, 65, 92 Through hole, 21-24 bolt, 30 base, 30A, 60A, 116A surface, 30B, 60B, 115B back surface, 32 annular convex part, 40, 41 moving piece, 42 , 43 Cylindrical part, 44, 45 Upper clamp part, 46, 47 Lower clamp part, 50 Sphere (base support member), 52 Contact part, 60 Intermediate, 60S Leaf spring member, 60T, 91 Convex part, 60U Tip convex part , 61 to 63 screw hole, 66 circular recess, 66A upper opening end, 66M hanging part, 66N nut, 67 cutout part, 68, 69 notch part, 70, 71 drive shaft, 80, 81 piezoelectric element (electromechanical conversion element) , 82, 83 Extendable portion, 84, 85 Other end portion, 86, 87 One end portion, 88, 89 Base, 90 Lower body, 100 Optical member attitude adjustment mechanism, 110 Michelson interferometer, 111 spectroscopic optical system, 112 light source, 113 collimating optical system, 114 beam splitter, 115 fixed mirror, 115A surface (optical surface), 116 moving mirror, 117 condensing optical system, 118 detector, 119 drive mechanism , 120 arithmetic unit, 121 reference optical system, 122 reference light source, 123 optical path synthesis mirror, 124 optical path separation mirror, 125 reference detector, 126 signal processing unit, 130 output unit, 1000 Fourier transform spectrometer, AR1 to AR5, AR82 , AR83, AR116 Arrow, D spot, E1 to E4 light receiving area, L1, L2 distance, S sample, V1, V3 inclined part, V2 rising part, V4 rising part.

Claims (8)

An optical member attitude adjustment mechanism for orienting an optical surface of an optical member in a predetermined direction by swinging the optical surface about a predetermined center point,
An electromechanical transducer element that expands and contracts in the axial direction by applying a predetermined voltage, and has one end fixed;
A drive shaft which is provided on the other end side of the electromechanical transducer and which moves forward and backward in the axial direction by expansion and contraction of the electromechanical transducer;
Supporting means for swingably supporting the optical member with the predetermined center point as a fulcrum,
The support means includes a moving piece that is located on the outer peripheral side of the optical member away from the predetermined center point and frictionally engages with the drive shaft,
The moving piece moves forward and backward with the drive shaft when the electromechanical conversion element slowly expands and contracts, and slides and moves with respect to the drive shaft when the electromechanical conversion element rapidly expands and contracts.
The posture of the optical member is adjusted by moving the outer peripheral side of the optical member forward and backward in the axial direction by the forward and backward movement and sliding movement of the movable piece.
Optical member attitude adjustment mechanism. The support means is
A base on which the optical member is supported from a surface opposite to the optical surface of the optical member, and the moving piece is provided on a part of an outer periphery;
A pedestal support member that is located on the opposite side of the optical member across the pedestal and that has a spherical contact surface formed in contact with the pedestal,
The contact portion is the predetermined center point;
As the moving piece moves forward and backward and slides, the pedestal swings with the contact portion with the pedestal support member as a fulcrum,
The posture of the optical member is adjusted through swinging of the pedestal.
The attitude adjustment mechanism for an optical member according to claim 1. The base support member is a sphere,
The posture adjustment mechanism of the optical member according to claim 2. The pedestal support member and the pedestal are each composed of a magnetic body that generates a magnetic force in a direction attracting each other.
The attitude adjustment mechanism for an optical member according to claim 2. At least two pairs of the electromechanical conversion element, the drive shaft, and the moving piece are provided with a predetermined angle interval when viewed from the center of the optical member.
The attitude adjustment mechanism for an optical member according to claim 1. The moving piece is moved along with the slow forward / backward movement of the drive shaft due to the expansion / contraction of the electromechanical conversion element, and the sliding movement is accompanied with a sharp forward / backward movement of the drive shaft due to the expansion / contraction of the electromechanical conversion element. And repeatedly adjusting the posture of the optical member,
Finely adjusting the posture of the optical member by causing the moving piece to move along with the slow movement of the drive shaft due to the expansion and contraction of the electromechanical transducer,
The attitude adjustment mechanism for an optical member according to claim 1. A posture adjustment mechanism for an optical member according to any one of claims 1 to 6,
The optical member being a fixed mirror;
A moving mirror,
A light source;
A beam splitter that divides the light emitted from the light source into light directed toward the optical member and light directed toward the movable mirror, and combines the light reflected on each of the optical member and the movable mirror to emit as interference light; ,
A detector for detecting the interference light,
Michelson interferometer. A Michelson interferometer according to claim 7,
A calculation unit for calculating a spectrum of the interference light detected by the detector;
An output unit that outputs the spectrum obtained by the arithmetic unit,
Fourier transform spectroscopic analyzer.

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