WO2009090771A1 - Interféromètre laser et instrument de mesure utilisant celui-ci - Google Patents

Interféromètre laser et instrument de mesure utilisant celui-ci Download PDF

Info

Publication number
WO2009090771A1
WO2009090771A1 PCT/JP2008/064150 JP2008064150W WO2009090771A1 WO 2009090771 A1 WO2009090771 A1 WO 2009090771A1 JP 2008064150 W JP2008064150 W JP 2008064150W WO 2009090771 A1 WO2009090771 A1 WO 2009090771A1
Authority
WO
WIPO (PCT)
Prior art keywords
laser
optical path
unit
light component
light
Prior art date
Application number
PCT/JP2008/064150
Other languages
English (en)
Japanese (ja)
Inventor
Toshihiro Nakayabu
Youichi Tamura
Hideo Yachi
Akihiro Shimizu
Original Assignee
Prefecture Ishikawa
Sigma Koki Co., Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Prefecture Ishikawa, Sigma Koki Co., Ltd filed Critical Prefecture Ishikawa
Priority to CN2008801248420A priority Critical patent/CN101918788A/zh
Publication of WO2009090771A1 publication Critical patent/WO2009090771A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02015—Interferometers characterised by the beam path configuration
    • G01B9/02017—Interferometers characterised by the beam path configuration with multiple interactions between the target object and light beams, e.g. beam reflections occurring from different locations
    • G01B9/02019—Interferometers characterised by the beam path configuration with multiple interactions between the target object and light beams, e.g. beam reflections occurring from different locations contacting different points on same face of object
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/447—Polarisation spectrometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/45—Interferometric spectrometry
    • G01J3/453—Interferometric spectrometry by correlation of the amplitudes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
    • G01B2290/15—Cat eye, i.e. reflection always parallel to incoming beam
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
    • G01B2290/70—Using polarization in the interferometer

Definitions

  • the present invention relates to a laser interferometer for measuring a positional deviation caused when a moving member such as a table of a machine tool moves in an axial direction with respect to a support member, and more specifically, outputs each light component.
  • the present invention relates to a laser interferometer that can be adjusted in parallel and a measurement apparatus using the same.
  • a bed that is fixed to a floor in a factory or the like and a table that moves on the bed are provided.
  • a work piece or the like is set on the table, and the work is performed while moving the table in a predetermined axial direction.
  • six positional deviations (errors) in the axial direction, the horizontal direction, the vertical direction, the pitch direction, the yaw direction, and the roll direction may occur. These positional deviations need to be measured for purposes such as delivery and maintenance.
  • This type of laser interferometer inputs a reflecting mirror as a reflecting means having two plane mirrors inclined at a predetermined angle so as to be substantially V-shaped, and a laser beam having two polarization components orthogonal to each other.
  • a laser interference unit serving as a laser beam path generating unit that outputs each light component after being reciprocated twice by a reflecting mirror.
  • the laser interference unit is disposed in a direction perpendicular to the polarization beam splitter with respect to the axial direction, a polarization beam splitter having a polarization plane as a spectroscopic unit, a biprism as a refraction unit disposed between the polarization beam splitter and the reflecting mirror And a turning mirror.
  • the polarization beam splitter has an input / output unit that allows laser light to be input and also allows laser light that has been reciprocated twice to and from a reflecting mirror to be output.
  • One light component separated by the polarizing beam splitter passes through the turning mirror and the biprism sequentially, is reflected by the reflecting mirror, passes through the biprism and the turning mirror sequentially, and returns to the polarizing beam splitter. Thereafter, one light component is emitted from the polarizing beam splitter, passes through the biprism, is reflected by the reflecting mirror, passes through the biprism, and returns to the polarizing beam splitter.
  • One light component separated in this way by the polarization beam splitter reciprocates twice between the biprism and the reflecting mirror.
  • the other light component separated by the polarizing beam splitter passes through the biprism, is reflected by the reflecting mirror, passes through the biprism, and returns to the polarizing beam splitter.
  • the other light component sequentially passes through the turning mirror and the biprism, is reflected by the reflecting mirror, passes through the biprism and the turning mirror in sequence, and returns to the polarizing beam splitter. In this way, the other light component reciprocates twice between the biprism and the reflecting mirror along an optical path different from the one light component.
  • each optical component of the laser light that has reciprocated between the biprism and the reflecting mirror is output from the laser interference unit.
  • the laser light (interference signal) of each light component output from this laser interference unit is received by a photoelectric converter, and by measuring the relative change of the two optical path lengths based on the phase difference of the wavelength of each light component. The positional deviation in the roll direction can be calculated.
  • the laser light that goes to the biprism via the turning mirror and the laser light that goes to the biprism without going through the turning mirror are parallel, the laser light refracted by the biprism and emitted is reflected in the reflecting mirror.
  • the light beams are vertically reflected and follow the same optical path as the forward path in the return path of the laser beam, so that each light component of the laser beam output from the laser interference unit is parallel.
  • the parallelism of the two light components output from the laser interference unit may decrease.
  • a polarizing beam splitter as an optical component is generally known in the form of a cube in which a polarizing surface is provided between the inclined surfaces of two 45 ° right-angle prisms and bonded with an adhesive. Production accuracy may be reduced due to shrinkage of the agent when it is dried. If the manufacturing accuracy of the optical component is reduced, the optical path may be shifted in the reciprocal process of each light component, and the parallelism of the two light components output from the laser interference unit may be reduced.
  • the angle of the turning mirror can be adjusted to make the two light components output from the laser interference section parallel, but the adjustment work is very difficult and easier to adjust.
  • a laser interferometer that can be used has been desired.
  • the present invention makes it easy to adjust the deflection of each light component, improves the parallelism of each light component of the laser light output from the laser light path generation means, and improves the measurement accuracy of the positional deviation in the roll direction. It is an object of the present invention to provide a laser interferometer that can be used, and a measuring apparatus using the same.
  • the present invention includes a reflecting means (2) having two plane mirrors (4, 5) inclined at a predetermined angle; A spectroscopic unit (8, 208) that inputs and splits laser light having two polarization components whose polarization planes are orthogonal to each other, and is disposed between the spectroscopic unit (8, 208) and the reflecting means (2).
  • the refracting section (6) refracts each light component dispersed by the spectroscopic section (8, 208) at the predetermined angle so as to enter and reflect perpendicularly to the plane mirror (4, 5) of the reflecting means (2).
  • laser light path generation means for outputting each light component after reciprocating twice between the refraction part (6) and the reflection means (2),
  • the reflecting means (2) and the laser beam path generating means 3, 103, 203
  • the reflecting means (2) and the laser beam path generating means 3 103, 203
  • a laser interferometer (1, 101, 201) in which the distance of the optical path through which each light component passes is relatively changed by the relative positional relationship with The laser beam path generation means (3, 103, 203)
  • the light splitting unit (8, 208) and the refraction so that one light component passes when the light components first reciprocate and the other light component passes when the light components reciprocate next time.
  • a laser interferometer comprising a deflection unit (15) disposed between the unit (6) and having a pair of wedge prisms (15a, 15b) that can adjust a deflection direction of a light component passing therethrough. (1, 101, 201).
  • each light component that is incident on the refracting unit by adjusting the deflecting unit is made parallel so that each light component is incident and reflected perpendicularly to the plane mirror of the reflecting unit.
  • the parallelism of the components can be improved.
  • the laser beam path generation means (3, 103, 203) is configured such that the axial direction (for example, the Z-axis direction) of the spectroscopic unit (8, 208). ) And a reflecting portion (9, 209) that is arranged in a direction perpendicular to the optical axis (for example, the Y-axis direction) and reflects the laser light incident through the spectroscopic portion (8, 208) toward the refracting portion (6).
  • the deflection unit (15) is disposed between the reflection unit (9, 209) and the refraction unit (6).
  • the deflecting unit is disposed between the reflecting unit and the refracting unit, it is not necessary to adjust the reflecting unit when adjusting the polarization direction of each light component, and the adjustment work is easy.
  • the laser beam path generation unit (203) is perpendicular to the axial direction (eg, Z-axis direction) of the spectroscopic unit (208) (eg, Y-axis direction).
  • a reflection unit (209) that is disposed and reflects the laser beam incident through the spectroscopic unit (208) toward the refraction unit (6);
  • the deflection unit (15) is disposed between the spectroscopic unit (208) and the reflection unit (209).
  • the deflecting unit is disposed between the spectroscopic unit and the reflecting unit, it is not necessary to adjust the reflecting unit when adjusting the polarization direction of each light component, and the adjustment work is easy.
  • the present invention includes a housing (3a) for storing the laser light path generation means (3, 103),
  • the deflection unit (15) includes ring-shaped operating elements (16a, 16b) formed on the outer periphery of the wedge prism (15a, 15b),
  • the wedge prisms (15a, 15b) are arranged in the casing (3a) so that the operating elements (16a, 16b) are exposed from the casing (3a).
  • the deflecting unit can be operated without disassembling the casing, and adjustment work is easy.
  • the spectroscopic unit (8) can freely input laser light and can output laser light reciprocated twice to the reflecting means (2).
  • the laser beam path generation means (103) includes a re-input unit (17) for returning the laser beam output from the input / output unit (8a) to the input / output unit (8a). .
  • the laser beam output by the re-input unit reciprocating twice between the refracting unit and the reflecting means is reciprocated twice between the refracting unit and the reflecting means, so that the sensitivity is improved.
  • the measurement accuracy of the positional deviation in the roll direction is improved.
  • the present invention (see FIGS. 1 and 2), the laser interferometer (1), Based on the phase difference of the wavelength of the laser light of each light component output from the laser light path generation means (3), the relative change in the distance of the light path of each light component is measured.
  • Laser length measuring means (12) to obtain, Either one of the reflecting means (2) and the laser beam path generating means (3) is fixed to a support member (21) supported by a reference floor (30);
  • the other of the reflecting means (2) and the laser beam path generating means (3) is fixed to a moving member (22) supported so as to be movable in the axial direction (for example, the Z-axis direction) with respect to the supporting member (21).
  • the relative positional relationship between the moving member and the supporting member can be measured without including the inclination of the supporting member due to the movement of the moving member, and the positional deviation in the roll direction can be measured well.
  • FIG. 9 is a cross-sectional view of the laser interference section along the line BB in FIG. 8.
  • the top view of the laser interference part seen from the arrow C direction in FIG.
  • FIG. 1 is a perspective view showing a measuring device and a machine tool when the laser interference unit is fixed to the table
  • FIG. 2 is a perspective view showing the measuring device and the machine tool when the reflecting mirror is fixed to the table
  • FIG. It is a perspective schematic diagram which shows the laser interferometer which concerns on this embodiment.
  • 4 is a perspective view of the laser interference portion
  • FIG. 5 is a cross-sectional view of the laser interference portion along the line AA in FIG.
  • FIG. 6 is an explanatory diagram showing the optical path of the laser beam passing through the deflecting unit
  • FIG. 6A is an explanatory diagram showing the optical path when the deflection direction of the laser beam is adjusted by the deflecting unit in the laser interference unit.
  • FIG. 6B is an explanatory diagram showing the deflection range of the laser light that passes through the deflecting unit.
  • a measuring device 50 that can measure the positional deviation of the machine tool 20 includes a laser interferometer 1 and a laser head (laser length measuring means) 12.
  • the machine tool 20 includes, for example, a bed (support member) 21 that is placed and supported on a floor 30 of a factory, and the bed 21 supports a guide member 21a.
  • a table (moving member) 22 is supported on the guide member 21a so as to be movable in the Z-axis direction (axial direction). The table 22 moves in the Z-axis direction by driving a motor (not shown), for example.
  • a tool post 23 is provided on the bed 21 of the machine tool 20, and an arm 24 provided on the tool post 23 has a chuck 25.
  • a tool such as a tool is attached to the chuck 25, a work piece is set and fixed on the table 22, and the work piece and the tool are brought into contact with each other by moving the table 22. Do the work.
  • the machine tool 20 shown in FIG. 1 is a schematic diagram that is simply shown for convenience of explanation, and has been described as an example that moves in the Z-axis direction. The operation is performed.
  • the laser head 12 is arranged on the floor 30 with, for example, a tripod 12b, and the laser head 12 has laser light having two polarization components orthogonal to each other, specifically, P waves (for example, linearly polarized light) (Longitudinal wave) and a laser oscillator capable of irradiating a laser beam having an S wave (for example, a transverse wave) that is a linearly polarized light having a plane of polarization orthogonal to the P wave and a different frequency, and the P wave of the input laser beam And a photoelectric converter capable of measuring the amount of change in the optical path length, which will be described in detail later, based on the wavelengths of the S wave and the S wave.
  • P waves for example, linearly polarized light
  • S wave for example, a transverse wave
  • a photoelectric converter capable of measuring the amount of change in the optical path length, which will be described in detail later, based on the wavelengths of the S wave and the S wave.
  • the laser head 12 is provided with an input / output head 12a that coaxially performs the irradiation of the laser light of the laser oscillator and the input of the laser light to the photoelectric converter.
  • the head 12a is directed to the input / output unit 8a of the laser interference unit 3 of the laser interferometer 1 to be described later, and is arranged so as to input / output laser light in the Z-axis direction.
  • the bed and table of the machine tool 20 have various names depending on their shapes and roles. For example, there are names such as a spindle head, a tool post, a column, and a stage.
  • the bed 21 is a support member supported by the floor 30, and the table 22 is a moving member that moves relative to the bed 21.
  • the laser head 12 is integrally provided with the laser oscillator and the photoelectric converter, but may be provided separately.
  • a laser interferometer 1 which is a main part of the present invention includes a reflecting mirror (reflecting means) 2 and a laser interfering section (laser optical path generating means) 3, and the reflecting mirror 2 is shown in FIG.
  • the two plane mirrors 4 and 5 are inclined at a predetermined angle substantially symmetrical with respect to the laser interference unit 3 so as to be substantially V-shaped.
  • the reflecting mirror 2 has a substantially rectangular parallelepiped reflecting mirror case 2a, and the plane mirrors 4 and 5 are stored in the main body case 2a.
  • a slit-like hole 2b through which laser light passes is formed on the surface of the main body case 2a that faces the laser interference portion 3.
  • the laser interference unit 3 includes a biprism (refractive unit) 6 having two wedge prisms 6a and 6b, quarter wavelength plates (second wavelength plates) 7a and 7b, polarization It has a beam splitter (spectral part) 8, a planar reflector (reflecting part) 9, a quarter wavelength plate (first wavelength plate) 10, a cube corner prism (optical path axis changing part) 11, and a deflecting part 15. It is comprised and is stored in the interference part case (casing) 3a of a substantially rectangular parallelepiped shape. 4 and 5, the biprism 6 and the cube corner prism 11 are attached to the interference part case 3a and exposed, but each optical component may be arranged inside the interference part case 3a.
  • a biprism (refractive unit) 6 having two wedge prisms 6a and 6b, quarter wavelength plates (second wavelength plates) 7a and 7b, polarization It has a beam splitter (spectral part) 8, a planar reflector (reflecting part) 9, a
  • the interference case 3a is formed with holes 3b through which the laser beam for the laser head 12 passes and holes 3c and 3d through which the laser beam for the reflecting mirror 2 passes.
  • the polarization beam splitter 8 includes a polarization plane 8b inclined at an angle of about 45 ° with respect to the Z-axis direction, and an input / output plane (input / output section) 8a for inputting and outputting laser light.
  • the input / output surface 8a is located on the opposite side of the Z-axis direction of the polarizing beam splitter 8 with respect to the reflecting mirror 2, that is, the input / output head 12a of the laser head 12 is in the Z-axis direction.
  • the planar reflector 9 is disposed in a direction perpendicular to the Z-axis direction of the polarizing beam splitter 8 (Y-axis direction), and has an angle of approximately 45 ° with respect to the Z-axis direction of the polarizing beam splitter 8. It is integrally formed on an inclined surface that is inclined in the direction.
  • the biprism 6 and quarter-wave plates 7a and 7b are disposed on the Z-axis direction between the polarizing beam splitter 8 and the planar reflector 9 and the reflector 2, respectively. Further, the cube corner prism 11 is disposed on the opposite side of the polarizing beam splitter 8 with respect to the planar reflector 9, and a quarter wavelength is provided between the cube corner prism 11 and the polarizing beam splitter 8. A plate 10 is arranged.
  • the positions of the biprism 6 and the quarter wavelength plates 7a and 7b in the Z-axis direction are as follows: the reflecting mirror 2, the biprism 6, the quarter wavelength plates 7a and 7b, and the polarization beam splitter. 8 and the planar reflector 9 are preferable, but the reflector 2, the quarter-wave plates 7a and 7b, the biprism 6, the polarization beam splitter 8, and the planar reflector 9 may be disposed in this order.
  • the quarter wave plates 7a and 7b are separate bodies, they may be integrated.
  • the quarter-wave plate is a crystal piece sliced accurately with respect to the crystal axis.
  • the quarter-wave plates 7a and 7b are tilted at 45 ° on the crystal axis in the XY plane.
  • the quarter-wave plate 10 is used with the crystal axis inclined at 45 ° in the XZ axis plane.
  • the deflecting unit 15 is formed on the outer periphery of a pair (two) of wedge prisms 15a and 15b that can adjust the deflection direction of the passing laser beam and the wedge prisms 15a and 15b.
  • Ring-shaped holders 16a and 16b for holding the prisms 15a and 15b, and more specifically between the polarizing beam splitter 8 and the biprism 6, more specifically between the planar reflector 9 and the biprism 6. are disposed between the quarter-wave plate 7 a and the flat reflector 9.
  • Each of the wedge prisms 15a and 15b has a disk shape in which both end surfaces are formed as planes, and one plane is a predetermined angle ⁇ w with respect to the other plane (XY plane) (see FIG. 6A). It is a wedge-shaped prism formed on an inclined surface that is inclined.
  • the wedge prisms 15a and 15b are arranged close to each other so that the planes of the wedge prisms 15a and 15b face each other, and the holders 16a and 16b of the wedge prisms 15a and 15b are aligned with the central axes of the wedge prisms 15a and 15b. It is supported in the interference part case 3a so as to be rotatable about the center.
  • the holders 16a and 16b are supported in the interference part case 3a so that the outer circumferences of the holders 16a and 16b are exposed to the outside of the interference part case 3a.
  • the exposed holders 16a and 16b may be operated, and it is not necessary to disassemble the interference case 3a. Therefore, the adjustment operation of the wedge prisms 15a and 15b is simple.
  • the wedge prisms 15a and 15b are rotated about the central axes of the wedge prisms 15a and 15b in the direction of arrow A (clockwise) or in the direction of arrow B (counterclockwise).
  • the deflection direction of the passing laser beam can be adjusted.
  • each wedge prism 15a and 15b is moved in the direction of arrow A or the arrow.
  • the laser beam emitted from the wedge prism 15b enters the wedge prism 15a is wedge prism 15a, 15b of the inclined surface of the inclined angle ⁇ predetermined substantially conical region R corresponding to w Is deflected in any direction that passes through. Therefore, the deflection direction of the laser beam can be adjusted by rotating the wedge prisms 15a and 15b in the direction of arrow A or arrow B.
  • the laser interferometer 1 of the first embodiment inputs laser light having S wave and P wave from the input / output surface 8a of the polarization beam splitter 8, and each light component dispersed by the polarization beam splitter 8 is A laser beam having two light components from the laser head 12 is configured to reciprocate twice between the biprism 6 and the reflecting mirror 2 of the laser interference unit 3 and output from the input / output surface 8a of the polarization beam splitter 8. Is input to the laser interferometer 3 of the laser interferometer 1 and the positional deviation in the roll direction is measured based on the interference signals generated by the two light components that are the outputs of the laser interferometer 3. Prior to this measurement operation, the laser head 12 emits laser light having two light components, and the reflecting mirror 2 and the laser interference unit 3 are deflected so that the respective light components output from the laser interference unit 3 are parallel to each other. It is necessary to adjust the part 15.
  • Laser light having P and S waves is output in parallel to the Z-axis direction from the laser oscillator of the laser head 12 and is input / output surface 8a of the polarization beam splitter 8 via optical paths a1 and b1 shown in FIG. Is input.
  • the laser beam input to the input / output surface 8a of the polarization beam splitter 8 is split into a first light component (P wave) and a second light component (S wave) by the polarization surface 8b, and the P wave is transmitted to the first optical path ( 3 passes through a2 to a11), and the S wave passes through the second optical path (b2 to b11 in FIG. 3).
  • the P wave passes through the polarization plane 8b of the polarization beam splitter 8 as it is and is output to the optical path a2 in the straight traveling direction, that is, the Z-axis direction, and the S wave is perpendicular to the polarization plane 8b, that is, Y
  • the light is reflected in the axial direction, passes through the polarization beam splitter 8, and reaches the planar reflecting mirror 9.
  • the first optical path through which the first light component passes is indicated by a broken line
  • the second optical path through which the second light component passes is indicated by a solid line.
  • each light component dispersed by the polarization beam splitter 8 is first reciprocated when reciprocating twice between the laser interference unit 3 and the reflecting mirror 2.
  • the P-wave laser light output to the optical path a2 passes through the quarter-wave plate 7b and becomes circularly polarized laser light.
  • the biprism 6 is refracted at an angle ⁇ with respect to the Z-axis direction by the wedge prism 6b and output to the optical path a3.
  • the circularly polarized laser light which is the first light component in the optical path a3, is input perpendicularly to the plane mirror 4 at the point 4b of the plane mirror 4 of the reflection mirror 2, and is reflected by the optical path a3.
  • the angle of the plane mirror 4 of the reflecting mirror 2 is adjusted by the operator so that the first light component is vertically incident and reflected.
  • the reflected circularly polarized laser beam in the optical path a3 is again refracted in the Z-axis direction by the wedge prism 6b, passes through the quarter-wave plate 7b, becomes S-wave laser light, and is output to the optical path a2. , Returned to the polarization beam splitter 8.
  • the first light component that has traveled straight in the Z-axis direction through the polarization plane 8b sequentially passes through the optical path a2, the quarter-wave plate 7b, the biprism 6, and the optical path a3, and is reflected by the plane mirror 4 of the reflecting mirror 2.
  • the optical path a3, the biprism 6, the quarter wavelength plate 7b, and the optical path a2 which are the same optical path as the forward path sequentially pass through the return path and return to the polarization plane 8b, and the biprism 6 of the laser interference unit 3 and
  • the first light component reciprocates with the reflecting mirror 2.
  • the S-wave laser light which is the light component dispersed by the polarization beam splitter 8 is transmitted by the bi-prism 6 by the planar reflecting mirror 9. The light is reflected in the arranged direction and output to the optical path b2.
  • the S-wave laser light in the optical path b2 passes through the wedge prisms 15a and 15b of the deflection unit 15 and is output to the optical path b3.
  • the deflection unit 15 deflects the S-wave laser light as the second light component. The direction is adjusted.
  • the S-wave laser light that is the second light component reflected by the polarization plane 8b is The optical path deviated from the Y-axis direction is traced.
  • the second light component reflected by the planar reflecting mirror 9 is parallel to the first light component that is shifted from the Z-axis direction and passes through the optical path b2 as in the optical path b3 ′ in the absence of the deflecting unit 15. In other words, the parallelism is extremely low.
  • the first embodiment as shown in FIG.
  • the operator rotates the wedge prisms 15a and 15b of the deflecting unit 15 in the arrow A direction or the arrow B direction.
  • the laser light passing through the deflecting unit 15 can be deflected within a predetermined substantially conical region R, and the second light component output to the optical path b3 is converted into the optical path a2 as shown in FIG. Since the deflection direction can be adjusted to be parallel to the first light component output to the first light component, the parallelism of the second light component passing through the optical path b3 with respect to the first light component passing through the optical path a2 is improved. Can be made.
  • the S-wave laser light which is the second light component adjusted in parallel with the first light component passing through the optical path a2 by the deflecting unit 15 and passed through the optical path b3 in the Z-axis direction, passes through the quarter-wave plate 7a.
  • the laser beam passes through to become circularly polarized laser light, and is refracted at an angle ⁇ with respect to the Z-axis direction by the wedge prism 6b of the biprism 6, and is output to the optical path b4.
  • the circularly polarized laser beam which is the second light component of the optical path b4, is reflected at the point 4a of the plane mirror 4 of the reflecting mirror 2.
  • the second light component passing through the optical path b3 is adjusted by the deflecting unit 15 to be parallel to the first light component passing through the optical path a2
  • the second light component passing through the optical path b4 is Similar to the first light component vertically incident / reflected at the point 4 b of the plane mirror 4, the light is vertically reflected at the point 4 a of the plane mirror 4.
  • the circularly polarized laser beam which is the second light component of the reflected optical path b4, is refracted in the Z-axis direction again by the wedge prism 6b and passes through the quarter-wave plate 7a to become a P-wave laser beam. , And output to the optical path b3.
  • the P-wave laser light in the optical path b3 is adjusted in the deflection direction by the deflecting unit 15 and output to the optical path b2, and is reflected by the planar reflecting mirror 9 toward the polarization plane 8b.
  • the second light component reflected by the polarization plane 8b sequentially passes through the planar reflector 9, the optical path b2, the deflecting unit 15, the optical path b3, the quarter wavelength plate 7a, the biprism 6, and the optical path b4.
  • the optical path b4, the biprism 6, the quarter-wave plate 7a, the optical path b3, the deflecting unit 15, the optical path b2, and the planar reflecting mirror 9 that are reflected by the plane mirror 4 of the reflecting mirror 2 are the same path as the forward path.
  • the laser beam passes through the polarization surface 8b in sequence, and the second light component reciprocates between the biprism 6 and the reflecting mirror 2 of the laser interference unit 3.
  • each light component dispersed by the polarization beam splitter 8 is reciprocated between the laser interference unit 3 and the reflecting mirror 2 for the second time.
  • the laser light that has passed through the optical path b2 and returned to the polarization plane 8b is a P wave, and thus travels straight through the polarization plane 8b. And pass through as it is and output to the optical path b5.
  • the P-wave laser light in the optical path b5 passes through the quarter-wave plate 10 and becomes circularly polarized laser light and is output to the optical path b6.
  • the circularly polarized laser light in the optical path b6 is transmitted by the cube corner prism 11.
  • the optical path b7 is output after being folded back onto the optical path b7 which is parallel to the axial direction of the optical path b6 and is on a different axis in the X-axis direction.
  • the circularly polarized laser light in the optical path b7 passes through the quarter wavelength plate 10 again to become S-wave laser light and is output to the optical path b8.
  • the laser beam in the optical path b8 is an S wave
  • the laser beam is reflected by the polarization plane 8b of the polarization beam splitter 8 to the optical path b9 in the perpendicular direction, that is, the Z-axis direction.
  • the second light component output to the optical path b9 is reflected on the polarization plane 8b at the same angle as the angle at which the second light component that has passed through the optical path b1 is reflected on the polarization plane 8b. Therefore, the first light component is output in parallel with the optical path a2 that has passed during the first round trip.
  • the S-wave laser light in the optical path b9 passes through the quarter-wave plate 7b to become circularly polarized laser light, and is refracted at an angle ⁇ with respect to the Z-axis direction by the wedge prism 6a of the biprism 6, and the optical path is output to b10.
  • the circularly polarized laser light which is the second light component of the optical path b10, is input perpendicularly to the plane mirror 5 at the point 5b of the plane mirror 5 of the reflecting mirror 2 and reflected by the optical path b10.
  • the angle of the plane mirror 5 of the reflecting mirror 2 is adjusted by the operator so that the second light component is vertically incident and reflected.
  • the reflected circularly polarized laser beam in the optical path b10 is refracted in the Z-axis direction again by the wedge prism 6a, passes through the quarter-wave plate 7b, becomes P-wave laser light, and is output to the optical path b9.
  • the Since the laser beam in the optical path b9 is a P wave, it passes through the polarization plane 8b of the polarization beam splitter 8 in the straight traveling direction as it is, and the first optical component in the optical path a1 and the second optical component in the optical path b1 To the parallel optical path b11.
  • the second light component reflected by the polarization plane 8b sequentially passes through the optical path b9, the quarter-wave plate 7b, the biprism 6, and the optical path b10, and is reflected by the plane mirror 5 of the reflecting mirror 2 so as to travel forward.
  • the optical path b10, the biprism 6, the quarter-wave plate 7b, and the optical path b9, which are the same optical path, sequentially pass through the return path and return to the polarization plane 8b, and the biprism 6 and the reflecting mirror 2 of the laser interference unit 3 are returned.
  • the second light component reciprocates between the two.
  • the second light component reciprocated twice with respect to the plane mirrors 4 and 5 of the reflecting mirror 2 is output to the optical path b11 from the input / output surface 8a, and then input to the photoelectric converter of the laser head 12.
  • the laser light returning to the optical path a2 is an S wave, so that the cube corner is formed by the polarization plane 8b of the polarization beam splitter 8.
  • the light is reflected in the direction in which the prism 11 is disposed and output to the optical path a4.
  • the first light component that has returned through the optical path a2 is reflected at the same angle as the reflection angle of the second light component that has passed through the optical path b1 and is reflected by the polarization plane 8b, and the second light component at this time Is output to the optical path a4 in a direction parallel to and opposite to the optical path a4.
  • the S-wave laser light in the optical path a4 passes through the quarter-wave plate 10 and becomes circularly polarized laser light and is output to the optical path a5.
  • the circularly polarized laser light in the optical path a5 is transmitted by the cube corner prism 11.
  • the optical path a6 is output after being folded back onto an optical path a6 that is parallel to the axial direction of the optical path a5 and is on a different axis in the X-axis direction.
  • the circularly polarized laser light in the optical path a6 passes through the quarter wavelength plate 10 again to become P-wave laser light and is output to the optical path a7.
  • the laser beam in the optical path a7 is a P wave
  • the laser beam travels straight through the polarization plane 8b of the polarization beam splitter 8 and is output to the planar reflecting mirror 9.
  • the planar reflecting mirror 9 causes the biprism 6 to The light is reflected in the arranged direction and output to the optical path a8.
  • a second light component reflected by the polarization plane 8b during the first reciprocation and traveling toward the planar reflecting mirror 9, and a first light component returning to the planar reflecting mirror 9 through the optical path b8 by folding the cube corner prism 11 are parallel. Accordingly, the first light component of the optical path a8 is parallel to the second light component of the optical path b2.
  • the P-wave laser light that is the first light component that has passed through the optical path a8 is deflected by the deflecting unit 15 in the same direction as the deflection direction of the second light component that has passed through the optical path b3, and passes through the optical path b9. It is adjusted parallel to the component and output to the optical path a9.
  • the second light component passes through the deflecting unit 15 during the first reciprocation, and the first light component passes through the deflecting unit 15 during the next reciprocation, so that the deflection direction of both light components is adjusted by the deflecting unit 15. It becomes.
  • the P-wave laser light which is the first light component in the optical path a9, passes through the quarter-wave plate 7a to become circularly polarized laser light, and is angled with respect to the Z-axis direction by the wedge prism 6a of the biprism 6.
  • the light is refracted by ⁇ and output to the optical path a10.
  • the circularly polarized laser beam which is the first light component in the optical path a10, is reflected at the point 5a of the plane mirror 5 of the reflecting mirror 2.
  • the P-wave laser light which is the first light component that passes through the optical path a9
  • the first light component that has passed through the optical path a10 is Similarly to the second light component vertically incident / reflected at the point 5 b of the plane mirror 5, the light is vertically reflected at the point 5 a of the plane mirror 5.
  • the circularly polarized laser beam which is the first light component of the reflected optical path a10, is refracted in the Z-axis direction again by the wedge prism 6a and passes through the quarter-wave plate 7a to become an S-wave laser beam. , And output to the optical path a9.
  • the S-wave laser light in the optical path a9 is adjusted in the deflection direction by the deflecting unit 15 and output to the optical path a8, and is reflected by the planar reflecting mirror 9 toward the polarization plane 8b.
  • the polarization plane 8b of the polarization beam splitter 8 Since the laser beam that has returned to the polarization plane 8b of the polarization beam splitter 8 along the same optical path as the forward path is an S wave, the polarization plane 8b of the polarization beam splitter 8 causes the second light component in the optical path b1 to be converted to the polarization plane 8b. Is reflected in the Z-axis direction at the same angle as the reflection angle when reflected at, and is parallel to the first light component of the optical path a1 and the second light component of the optical path b1, and is output from the input / output surface 8a to the optical path a11. .
  • the first light component that has passed through the polarization plane 8b sequentially passes through the planar reflecting mirror 9, the optical path a8, the deflecting unit 15, the optical path a9, the quarter wavelength plate 7a, the biprism 6, and the optical path a10, Reflected by the plane mirror 5 of the reflecting mirror 2, the optical path a 10, the biprism 6, the quarter-wave plate 7 a, the optical path a 9, the deflecting unit 15, the optical path a 8, and the planar reflecting mirror 9 are sequentially returned as the return path. It passes through and returns to the polarization plane 8b, and the first light component reciprocates between the biprism 6 and the reflecting mirror 2 of the laser interference unit 3.
  • the first light component reciprocated twice with respect to the plane mirrors 4 and 5 of the reflecting mirror 2 is output from the input / output surface 8a to the optical path a11 and then input to the photoelectric converter of the laser head 12.
  • the first light component of the optical path a11 and the second light component of the optical path b11 that have reciprocated twice with respect to the plane mirrors 4 and 5 of the reflecting mirror 2 are parallel to the input laser light, They are output in parallel with each other.
  • optical paths a1 and b1, optical paths a4 and b5, optical paths a5 and b6, optical paths a6 and b7, optical paths a7 and b8, and optical paths a11 and b11 shown in FIG. 3 are shown as parallel axes for convenience of explanation. However, these optical paths are optical paths on the same axis.
  • the laser light having the first light component and the second light component irradiated from the laser head 12 is input from the input / output surface 8a, is split by the polarization surface 8b, and is reflected by the biprism 6. Since the second light component passes through the deflecting unit 15 during the first reciprocation with the mirror 2, and the first light component passes through the deflecting unit 15 during the next reciprocation, the pair of wedge prisms 15a and 15b of the deflecting unit 15 is used. Can be rotated to adjust the deflection direction of each light component. By the adjustment operation, each light component emitted to the biprism 6 can be made parallel, and each light component can be made perpendicular to the reflecting mirror 2. Can be incident and reflected.
  • each light component can follow the same light path in the forward path and the return path, and each light component output from the input / output surface can be made parallel to each other. Therefore, the parallelism of each light component output from the laser interference unit 3 can be improved.
  • both light components pass through the pair of wedge prisms 15a and 15b, it is not necessary to prepare a pair of wedge prisms for each light component, so the number of parts is reduced and the structure is simple. It becomes.
  • the reflecting mirror 2 moves relative to the laser interference unit 3 in the roll direction, which is the ⁇ direction around the Z axis.
  • the points 4a and 5b and the points 4b and 5a at which the laser beams passing through the first optical path and the second optical path are reflected are the points 4a and 5b on the valley side (that is, the inner side).
  • the mountain side (that is, the outside) the point 4 b and the point 5 a move to the mountain side (that is, the outside) or the valley side (that is, the inside) with respect to the inclination of the plane mirrors 4 and 5.
  • the optical path lengths of the optical path a3 and the optical path a10 are shortened or extended with respect to the optical path lengths of the optical path b4 and b10, and a relative change occurs in the optical path lengths of the first optical path and the second optical path.
  • the S-wave laser light that is the first optical component of the optical path a11 output from the input / output surface 8a and the second light in the optical path b11 A Doppler frequency shift with the component P-wave laser light occurs, and an interference signal is obtained.
  • a change in the optical path length (hereinafter referred to as “detection light length”) can be detected by the photoelectric converter of the laser head 12 to which the interference signal is input.
  • detection light length detection of the Doppler frequency shift by this photoelectric converter is a well-known technique, the description is abbreviate
  • the relationship between the angle ⁇ in the roll direction and the change amount ⁇ of the optical path length does not depend on the distance 2u between the point 4a and the point 5a (the point 4b and the point 5b), that is, the distance between the reflecting mirror 2 and the laser interference unit 3. Has no effect.
  • the relationship of the above formula 1 is that the detected light length (mm) and the generated rolling (square second) Obtained as a relationship.
  • each light component output from the laser interference unit 3 can be made parallel, a good interference signal can be obtained and detected when measuring the positional deviation in the roll direction. Since the error of the change ⁇ in the optical path length is also reduced, the measurement accuracy of the positional deviation in the roll direction is improved.
  • optical path lengths of the optical path b4 and the optical path b10 and the optical path lengths of the optical path a3 and the optical path a10 are not expanded, contracted, or changed, and no relative change occurs between the two optical path lengths.
  • a measuring device 50 including the laser interferometer 1 is installed in the machine tool 20 as shown in FIG.
  • the reflecting mirror 2 of the laser interferometer 1 is fixed on the bed 21 of the machine tool 20, and the laser interference unit 3 is fixed on the table 22.
  • the reflecting mirror 2 and the laser interference unit 3 are accurately aligned in the Z-axis direction, and the angle of the plane mirrors 4 and 5 and the angle of the laser interference unit 3 are accurate with respect to the Z-axis direction.
  • the laser head 12 is installed on the floor 30 so that the input / output head 12a is aligned with the input / output surface 8a of the laser interference unit 3 in the Z-axis direction.
  • the table 22 of the machine tool 20 is moved in the Z-axis direction with respect to the bed 21, and the position deviation in the roll direction ( ⁇ direction) accompanying the movement of the table 22 is measured by the measuring device 50.
  • the input / output surface 8a of the laser interference unit 3 moves in the Z-axis direction, and the input / output head 12a of the laser head 12 is also directed in the Z-axis direction. Even if it moves in the direction, the input / output of the laser beam to the input / output surface 8a does not shift. Further, if the laser interference unit 3 only moves in the Z-axis direction, the optical path lengths of the first optical path and the second optical path only expand and contract, and no relative optical path length difference occurs.
  • the reflecting mirror 2 of the laser interferometer 1 is fixed on the table 22 of the machine tool 20 as shown in FIG. It may be fixed on the bed 21.
  • the laser head 12 is installed on the floor 30 so that the input / output head 12a is aligned with the input / output surface 8a of the laser interference unit 3 in the Z-axis direction.
  • the measurement apparatus 50 of the first embodiment prior to the measurement, it is possible to easily perform the operation of adjusting each light component output from the laser interference unit 3 of the laser interferometer 1 in parallel.
  • a good interference signal can be obtained, and the measurement accuracy of the positional deviation in the roll direction can be improved.
  • FIG. 7 is a schematic perspective view showing a laser interferometer according to the second embodiment.
  • FIG. 8 is a perspective view showing the laser interference unit.
  • FIG. 9 is a cross-sectional view of the laser interference portion taken along line BB in FIG.
  • FIG. 10 is a plan view of the laser interference unit viewed from the direction of arrow C in FIG.
  • the same reference numerals are given to the same parts as those in the first embodiment except for some changed parts, and the description thereof is omitted.
  • a laser interferometer 101 according to the second embodiment includes a reflecting mirror 2 and a laser interference unit 103.
  • the laser interference unit 103 is further added to the configuration of the laser interference unit 3 according to the first embodiment.
  • a cube corner prism (re-input unit) 17 is provided.
  • the cube corner prism 17 is disposed in the vicinity of the input / output surface 8a of the polarization beam splitter 8, and is fixed to the interference part case 3a by a fixing bracket 18. Further, as shown in FIG. 10, the cube corner prism 17 is arranged avoiding the point D1 where the laser beam is input and the point D4 for outputting the laser beam on the input / output surface 8a.
  • the cube corner prism 17 is disposed so as to face a point D2 where the laser beam is output by two reciprocations between the biprism 6 and the reflecting mirror 2 and a point D3 where the laser beam is re-input.
  • the cube corner prism 17 is fixed to the outside of the interference portion case 3a and exposed to the outside. However, the cube corner prism 17 is exposed to the interference portion case 3a. In either case, it is expressed as being stored in the interference part case 3a.
  • Laser light having a P wave and an S wave is output in parallel to the Z-axis direction from the laser oscillator of the laser head, and is input to the input / output surface 8a of the polarization beam splitter 8 via the optical paths c1 and d1 shown in FIG. Is done.
  • the laser beam is input to the point D1 on the input / output surface 8a shown in FIG.
  • the laser beam input to the input / output surface 8a of the polarization beam splitter 8 is split into a first light component (P wave) and a second light component (S wave) by the polarization surface 8b, and the first light component is the first light component.
  • the light passes through the optical path (c2 to c22 in FIG.
  • the second light component passes through the second optical path (d2 to d22 in FIG. 7).
  • the P wave passes through the polarization plane 8b of the polarization beam splitter 8 as it is and is output to the optical path c2 in the straight direction, that is, the Z-axis direction, and the S wave is perpendicular to the polarization plane 8b, that is, Y
  • the light is reflected in the axial direction, passes through the polarization beam splitter 8, and reaches the planar reflecting mirror 9.
  • the first optical path through which the first light component passes is indicated by a broken line
  • the second optical path through which the second light component passes is indicated by a solid line.
  • the first light component passing through the first optical path sequentially passes through the optical path c2, the quarter wavelength plate 7b, the wedge prism 6b of the biprism 6, and the optical path c3.
  • the light enters and reflects perpendicularly to the plane mirror 4, and sequentially passes through the optical path c ⁇ b> 3, the wedge prism 6 b, the quarter wavelength plate 7 b, and the optical path c ⁇ b> 2 and returns to the polarization beam splitter 8.
  • the laser light that has returned to the optical path c2 is an S wave, and is reflected by the polarization surface 8b of the polarization beam splitter 8 in the direction in which the cube corner prism 11 is disposed, and the optical paths c4 and 1/4.
  • the wave plate 10 and the optical path c5 are sequentially passed, and the cube corner prism 11 returns to the optical path c6 which is parallel to the axial direction of the optical path c5 and is on an axis having a different diagonal position in the XZ plane.
  • the first light component sequentially passes through the optical path c6, the quarter wavelength plate 10, and the optical path c7.
  • the laser beam in the optical path c7 is a P wave, and travels straight through the polarization plane 8b of the polarization beam splitter 8 and passes through the planar reflecting mirror 9 and the optical path c8 sequentially.
  • the optical path c9, the quarter-wave plate 7a, the wedge prism 6a of the biprism 6 and the optical path c10 are sequentially passed, and enters and reflects perpendicularly to the plane mirror 5 of the reflecting mirror 2, and the optical path c10, the wedge prism 6a, 1 /
  • the light passes through the four-wavelength plate 7 a, the optical path c 9, the deflecting unit 15, the optical path c 8, and the planar reflection mirror 9 and returns to the polarization plane 8 b of the polarization beam splitter 8.
  • the laser beam that has returned to the polarization plane 8b of the polarization beam splitter 8 is an S wave, is reflected in the Z-axis direction by the polarization plane 8b of the polarization beam splitter 8, and is output from the input / output plane 8a to the optical path c11. .
  • the laser beam output to the optical path c11 is output from the point D2 that is positioned diagonally to the point D1 on the XY plane of the input / output surface 8a shown in FIG.
  • the first light component output to the optical path c11 passes through the optical path c12 on the axis parallel to the axis of the optical path c11 and different in the Y-axis direction by the cube corner prism 17, and again.
  • the light is input to the input / output surface 8 a of the polarization beam splitter 8.
  • the laser beam output to the optical path c12 is input to a point D3 that is shifted by a predetermined distance in the Y-axis direction from the point D2 on the input / output surface 8a shown in FIG.
  • the first light component that has passed through the optical path c12 is an S wave
  • it is reflected by the polarization plane 8b, sequentially passes through the planar reflector 9 and the optical path c13, and the deflection direction is adjusted by the deflecting unit 15, and the optical path c14, the quarter-wave plate 7a, the wedge prism 6a of the biprism 6, and the optical path c15 are sequentially entered and reflected perpendicularly to the plane mirror 5 of the reflecting mirror 2, and the optical path c15, the wedge prism 6a, and the quarter-wave plate 7a. Then, the light passes through the optical path c14, the deflecting unit 15, the optical path c13, and the planar reflecting mirror 9 and returns to the polarization plane 8b of the polarization beam splitter 8.
  • the laser light that has returned to the polarization plane 8b of the polarization beam splitter 8 is a P-wave, passes straight through the polarization plane 8b of the polarization beam splitter 8, and passes through the optical path c16, the quarter wavelength plate 10, and the optical path.
  • the light passes through c17 sequentially, and is output by the cube corner prism 11 by folding back to an optical path c18 which is parallel to the axial direction of the optical path c17 and is on an axis having a different diagonal position in the XZ plane.
  • the laser beam in the optical path c18 sequentially passes through the quarter-wave plate 10 and the optical path c19, and returns to the polarization plane 8b of the polarization beam splitter 8 as S-wave laser light.
  • the returned laser light is reflected by the polarization plane 8b and sequentially passes through the optical path c20, the quarter wavelength plate 7b, the wedge prism 6b of the biprism 6, and the optical path c21, and enters the plane mirror 4 of the reflecting mirror 2 perpendicularly.
  • the light passes through the optical path c 21, the wedge prism 6 b, the quarter wavelength plate 7 b, and the optical path c 20, and returns to the polarization plane 8 b of the polarization beam splitter 8.
  • the returned laser light of the first light component is a P wave, passes straight through the polarization plane 8b of the polarization beam splitter 8, and is output from the input / output plane 8a to the optical path c22.
  • the laser beam output to the optical path c22 is output from the point D4 that is at the diagonal position of the point D3 on the XY plane of the input / output surface 8a shown in FIG. .
  • the laser beam of the first light component is reciprocated between the biprism 6 and the reflecting mirror 2 and output to the cube corner prism 17, and then returned to the input / output surface 8a by the cube corner prism 17. Furthermore, since the bi-prism 6 and the reflecting mirror 2 are reciprocated twice and output from the input / output surface 8a, the bi-prism 6 and the reflecting mirror 2 are twice as large as the first embodiment. It is output from the input / output surface 8a after four reciprocations.
  • the first light component reciprocating four times with respect to the plane mirrors 4 and 5 of the reflecting mirror 2 is output from the input / output surface 8a to the optical path c22 and then input to the photoelectric converter of the laser head.
  • the S-wave laser light which is the light component dispersed by the polarization beam splitter 8 sequentially passes through the planar reflector 9 and the optical path d2.
  • the deflection direction is adjusted by the deflecting unit 15, sequentially passes through the optical path d3, the quarter-wave plate 7a, the wedge prism 6b, and the optical path d4, and is vertically incident and reflected by the plane mirror 4 of the reflecting mirror 2, and the optical path d4,
  • the light passes through the wedge prism 6 b, the quarter-wave plate 7 a, the optical path d 3, the deflecting unit 15, the optical path d 2, and the planar reflection mirror 9, and returns to the polarization plane 8 b of the polarization beam splitter 8.
  • the returned laser light of the second light component is a P wave, it travels straight through the polarization plane 8b and passes through the optical path d5, the quarter wavelength plate 10, and the optical path d6 in order, and the cube corner.
  • the prism 11 the light is returned to the optical path d 7 which is parallel to the axial direction of the optical path d 6 and is on an axis having a different diagonal position in the XZ plane.
  • the laser beam in the optical path d7 sequentially passes through the quarter-wave plate 10 and the optical path d8, and returns to the polarization plane 8b of the polarization beam splitter 8 as S-wave laser light.
  • the returned laser light is reflected by the polarization plane 8b, sequentially passes through the optical path d9, the quarter-wave plate 7b, the wedge prism 6a, and the optical path d10, and enters and reflects perpendicularly by the plane mirror 5 of the reflecting mirror 2, and the optical path. It passes through d10, the wedge prism 6a, the quarter wavelength plate 7b, and the optical path d9 in order, and returns to the polarization plane 8b of the polarization beam splitter 8.
  • the returned laser light of the second light component is a P wave, passes through the polarization plane 8b of the polarization beam splitter 8 in the straight traveling direction, and is output from the input / output plane 8a to the optical path d11.
  • the laser beam output to the optical path d11 is output from a point D2 opposite to the cube corner prism 17 at the diagonal position of the point D1 on the XY plane of the input / output surface 8a shown in FIG. .
  • the second light component output to the optical path d11 passes through the optical path d12 on the axis parallel to the axis of the optical path d11 and different in the Y-axis direction by the cube corner prism 17, and again.
  • the light is input to the input / output surface 8 a of the polarization beam splitter 8.
  • the laser beam output to the optical path d12 is input to a point D3 that is shifted by a predetermined distance in the Y-axis direction from the point D2 on the input / output surface 8a shown in FIG.
  • the second light component that has passed through the optical path d12 is a P wave, it passes through the polarization plane 8b as it is, and sequentially passes through the optical path d13, the quarter wavelength plate 7b, the wedge prism 6a, and the optical path d14, and the reflecting mirror. 2 is reflected vertically by the plane mirror 5, passes through the optical path d 14, the wedge prism 6 a, the quarter-wave plate 7 b, and the optical path d 13 in order, and returns to the polarization plane 8 b of the polarization beam splitter 8.
  • the laser beam returning to the polarization plane 8b of the polarization beam splitter 8 is an S wave, is reflected by the polarization plane 8b of the polarization beam splitter 8, and sequentially passes through the optical path d15, the quarter wavelength plate 10, and the optical path d16. Then, the cube corner prism 11 returns the light to the optical path d17 which is parallel to the axial direction of the optical path d16 and is on an axis having a different diagonal position in the XZ plane.
  • the laser beam in the optical path d17 sequentially passes through the quarter-wave plate 10 and the optical path d18, and returns to the polarization plane 8b of the polarization beam splitter 8 as a P-wave laser beam.
  • the returned laser light travels straight through the polarization plane 8b of the polarization beam splitter 8, passes through as it is, sequentially passes through the planar reflector 9 and the optical path d19, the deflection direction is adjusted by the deflecting unit 15, and the optical path d20,
  • the 1 ⁇ 4 wavelength plate 7a, the wedge prism 6b, and the optical path d21 are sequentially passed, and vertically incident and reflected by the plane mirror 5 of the reflecting mirror 2, and the optical path d21, the wedge prism 6b, the 1 ⁇ 4 wavelength plate 7a, the optical path d20, and the deflecting unit. 15, sequentially passes through the optical path d 19 and the planar reflector 9, and returns to the polarization plane 8 b of the polarization beam splitter 8.
  • the laser light that has returned to the polarization plane 8b of the polarization beam splitter 8 is an S wave, is reflected in the Z-axis direction by the polarization plane 8b of the polarization beam splitter 8, and is output from the input / output plane 8a to the optical path d22.
  • the laser beam output to the optical path d22 is output from the point D4 that is at the diagonal position of the point D3 on the XY plane of the input / output surface 8a shown in FIG. .
  • the laser light of the second light component is reciprocated between the biprism 6 and the reflecting mirror 2 and output to the cube corner prism 17, and then returned to the input / output surface 8a by the cube corner prism 17. Furthermore, since the bi-prism 6 and the reflecting mirror 2 are reciprocated twice and output from the input / output surface 8a, the bi-prism 6 and the reflecting mirror 2 are twice as large as the first embodiment. It is output from the input / output surface 8a after four reciprocations.
  • the second light component reciprocated four times with respect to the plane mirrors 4 and 5 of the reflecting mirror 2 is output from the input / output surface 8a to the optical path d22 and then input to the photoelectric converter of the laser head.
  • the laser light outputted by the cube corner prism 17 by reciprocating twice between the biprism 6 and the reflecting mirror 2 is returned to the biprism 6 and the reflecting mirror 2 again. Since the optical path length of each light component is twice that of the first embodiment, and the positional deviation in the roll direction occurs, the amount of change in the optical path length is double. Become. Accordingly, the detection sensitivity is doubled in the photoelectric converter of the laser head 12 that detects the change in the optical path length, and the measurement accuracy of the positional deviation in the roll direction is improved.
  • the laser light having the first light component and the second light component irradiated from the laser head 12 is input from the input / output surface 8a and dispersed by the polarization surface 8b, and the biprism 6 Since the second light component is adjusted in the polarization direction in the deflecting unit 15 during the first round-trip between the mirror 2 and the reflecting mirror 2, and the first light component is adjusted in the polarization direction in the deflecting unit 15 during the next round-trip.
  • Each light component output to the prism 17 can be made parallel.
  • each light component of the parallel laser light input again from the input / output surface 8 a by the cube corner prism 17 is also split by the polarization surface 8 b and is first reciprocated between the biprism 6 and the reflecting mirror 2.
  • the amount of adjustment of the deflecting unit 15 is adjusted when laser light is input again. Even if it does not change, each output light component can be made parallel. Therefore, when measuring the positional deviation in the roll direction, a good interference signal can be obtained, and the measurement accuracy of the positional deviation in the roll direction can be improved.
  • FIG. 11 is a diagram showing roll detection sensitivity measured by the measurement apparatus of the first embodiment
  • FIG. 12 is a diagram showing roll detection sensitivity measured by the measurement apparatus of the second embodiment. is there.
  • the reflection mirror 2 in the laser interferometer 1 of the first embodiment is incident and reflected four times in total including the first light component and the second light component, and the laser interference of the second embodiment.
  • the total reflection of the first light component and the second light component on the reflecting mirror 2 in the total 101 is 8 times.
  • the horizontal axis is an angle (roll) obtained by rotating the reflecting mirror 2 in the roll direction, and the vertical axis is detected using the laser interferometers 1 and 101 with respect to the roll of the reflecting mirror 2.
  • L is the distance between the reflecting mirror 2 and the biprism 6.
  • the plotting position of the data is shifted upward as the value of L increases to make it easy to see. .
  • L 300 (mm)
  • the detection light length is shifted upward by 0.01 (mm) and plotted, but the actual detection light length is 0.01 (mm) from the plot position.
  • the roll detection sensitivity of the measuring apparatus including the laser interferometers 1 and 101 is the slope of the regression line of the measurement data, and the greater the slope of the regression line of the measurement data, the higher the detection sensitivity.
  • the roll detection sensitivity of the measurement apparatus according to the first embodiment shown in FIG. 11 is 0.81 ⁇ 10 ⁇ 5 regardless of the value of L, and is equal to the distance between the reflecting mirror 2 and the biprism 6. It was confirmed that it did not depend.
  • the roll detection sensitivity of the measurement apparatus of the second embodiment shown in FIG. 12 is 1.63 ⁇ 10 ⁇ 5 regardless of the value of L, which also causes It was confirmed that it did not depend on the distance to the prism 6. It was confirmed that the roll detection sensitivity of the measurement apparatus of the second embodiment is twice the roll detection sensitivity of the measurement apparatus of the first embodiment.
  • FIG. 13 is a diagram illustrating a result of detecting a positional deviation in the roll direction of the optical experimental bench.
  • a table was placed on the optical test bench, and the position deviation in the roll direction was detected by moving the table.
  • the detection light length what is obtained from the laser interferometer 101 is the detection light length.
  • the roll detection sensitivity (1.63 ⁇ 10 ⁇ 5 ) shown in FIG. 12 as calibration data.
  • the positional deviation in the roll direction is calculated. Yes. More specifically, the roll shown in FIG. 13, that is, the positional deviation in the roll direction, is obtained by dividing the detection light length obtained from the laser interferometer 101 by the roll detection sensitivity, which is calibration data.
  • FIG. 14 is a schematic perspective view showing a laser interferometer according to the third embodiment.
  • the same reference numerals are given to the same parts as those in the first or second embodiment except for some changed parts, and the description thereof is omitted.
  • the laser interference unit 203 of the laser interferometer 201 separates the polarization beam splitter (spectral unit) 208 and the planar reflector (reflecting unit) 209. And a planar reflecting mirror 209 is arranged in a direction perpendicular to the Z-axis direction of the polarizing beam splitter 208 (Y-axis direction).
  • the deflecting unit 15 is disposed between the planar reflecting mirror 209 and the quarter-wave plate 7a.
  • the deflecting unit 15 it is not necessary to adjust the angle of the planar reflecting mirror 209 when adjusting each light component output from the laser interference unit 203 in parallel, and each of the deflecting units 15 can be adjusted. Since only the wedge prisms 15a and 15b need to be adjusted, the adjustment work is simple.
  • the deflecting unit 15 is disposed between the planar reflector 209 and the quarter-wave plate 7a.
  • the present invention is not limited to this.
  • the deflecting unit 15 may be disposed between the polarizing beam splitter 208 and the planar reflecting mirror 209. This also makes it unnecessary to adjust the angle of the planar reflecting mirror 209 when adjusting the output light components in parallel, and it is only necessary to adjust the wedge prisms 15a and 15b of the deflecting unit 15. Easy to work.
  • the deflecting unit 15 is disposed between the planar reflectors 9 and 209 and the quarter-wave plate 7a. Instead, for example, a broken line in FIG. As shown, the deflecting unit 15 may be disposed between the quarter-wave plate 7 a and the biprism 6. Further, instead of providing the deflecting unit 15 in the optical path passing through the polarizing beam splitters 8 and 208, the reflecting mirrors 9 and 209, the quarter wavelength plate 7a, and the biprism 6, the polarizing beam splitters 8, 208 and quarter wavelength plates are provided.
  • an optical path passing through the biprism 6, that is, the deflecting unit 15 is disposed between the polarization beam splitters 8 and 208 and the quarter wavelength plate 7b, or between the quarter wavelength plate 7b and the biprism 6. You may make it do.
  • the interference part may have an amic prism (not shown) as a reflection part.
  • the laser interferometer 1, 101, 201 is used to measure the positional deviation in the roll direction ( ⁇ direction).
  • 201 can be used in a shape rotated 90 degrees, that is, in a horizontal direction.
  • the measurement device 50 for measuring the machine tool 20 has been described.
  • the measurement device 50 is not limited to the machine tool, and is not limited to the machine tool, but in the axial direction with respect to the support member and the support member.
  • the measurement device 50 is a moving member that can be installed (fixed) to the reflecting mirror 2 and the laser interference units 3, 103, 203, the positional deviation of them can be measured. Is possible.
  • the input / output surfaces of the laser interference units 3, 103, and 203 are positioned on the opposite side in the axial direction of the polarization beam splitters 8 and 208 with respect to the reflecting mirror 2.
  • the present invention is not limited to this, and the input / output surface of the polarization beam splitter is formed in a direction perpendicular to the axial direction so that the laser interference unit inputs and outputs laser light in the direction perpendicular to the axial direction. It may be configured.
  • the laser interference unit 103 includes one cube corner prism 17 as a re-input unit, and the laser beam is reciprocated four times between the biprism 6 and the reflecting mirror 2.
  • the present invention is not limited to this, and the laser interference unit includes a plurality of cube corner prisms (N: N is an integer of 2 or more) as a re-input unit. It may be a case where it is configured to reciprocate 2 ⁇ (N + 1).
  • the laser interferometer and measuring apparatus are used for measuring a positional deviation that occurs when a moving member such as a table of a machine tool moves in an axial direction with respect to a supporting member, and in particular, a positional deviation in a roll direction. Suitable for measurement.

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Instruments For Measurement Of Length By Optical Means (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

La présente invention a pour objet un interféromètre laser (1) comportant un miroir réfléchissant (2) ayant deux miroirs plans (4, 5), et une section d'interférométrie laser (3) ayant un séparateur (8) de faisceau polarisant pour accepter deux lumières polarisées linéaires à intersection orthogonale pour la dispersion, et un prisme double (6) pour réfracter chacun des composants optiques dispersés qui sont incidents et réfléchis verticalement sur les miroirs plans (4, 5) et à partir de ceux-ci, de sorte à délivrer chacun des composants optiques après deux renvois de chaque composant optique entre le prisme double (6) et le miroir réfléchissant (2). La section d'interférométrie laser (3) est pourvue d'une section de déviation (15) ayant une paire de prismes d'angle (15a, 15b) qui sont agencés entre le séparateur (8) de faisceau polarisant et le prisme double (6) de sorte qu'un composant optique passe quand chaque composant optique est renvoyé au début, tandis que l'autre composant optique passe quand chaque composant optique est renvoyé à la suite, et à permettre un réglage souple de la direction de déviation du composant optique traversant. Un tel agencement simplifie le travail de réglage de déviation pour chaque composant optique, améliore le parallélisme de chaque composant optique du faisceau laser sortant et la précision de la mesure de la déviation positionnelle dans la direction du rouleau.
PCT/JP2008/064150 2008-01-18 2008-08-06 Interféromètre laser et instrument de mesure utilisant celui-ci WO2009090771A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2008801248420A CN101918788A (zh) 2008-01-18 2008-08-06 激光干涉仪和使用该激光干涉仪的测量装置

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008009032A JP2009168709A (ja) 2008-01-18 2008-01-18 レーザ干渉計、及びそれを用いた測定装置
JP2008-009032 2008-01-18

Publications (1)

Publication Number Publication Date
WO2009090771A1 true WO2009090771A1 (fr) 2009-07-23

Family

ID=40885178

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2008/064150 WO2009090771A1 (fr) 2008-01-18 2008-08-06 Interféromètre laser et instrument de mesure utilisant celui-ci

Country Status (3)

Country Link
JP (1) JP2009168709A (fr)
CN (1) CN101918788A (fr)
WO (1) WO2009090771A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102042804B (zh) * 2009-10-13 2012-12-12 上海微电子装备有限公司 激光干涉仪测量装置和方法
CN114264255A (zh) * 2021-12-28 2022-04-01 中国科学院上海天文台 一种基于干涉位移测量系统的滚转角测量系统和方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101665645B1 (ko) * 2015-01-09 2016-10-13 한국산업기술대학교산학협력단 복수의 수평 레이저 시스템
CN113101072B (zh) * 2021-04-07 2022-03-25 刘新艳 一种具有躺椅功能的医疗护理用轮椅

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02297010A (ja) * 1989-05-12 1990-12-07 Futaba Corp 測長装置
JPH05231816A (ja) * 1992-02-25 1993-09-07 Nikon Corp 干渉計
JP2000314609A (ja) * 1999-05-06 2000-11-14 Nikon Corp レーザ干渉測長装置
JP2004138433A (ja) * 2002-10-16 2004-05-13 Ishikawa Pref Gov レーザ干渉計、及びそれを用いた測定装置
WO2007020738A1 (fr) * 2005-08-16 2007-02-22 Tokyo Seimitsu Co., Ltd. Dispositif de mesure de longueur au laser

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02297010A (ja) * 1989-05-12 1990-12-07 Futaba Corp 測長装置
JPH05231816A (ja) * 1992-02-25 1993-09-07 Nikon Corp 干渉計
JP2000314609A (ja) * 1999-05-06 2000-11-14 Nikon Corp レーザ干渉測長装置
JP2004138433A (ja) * 2002-10-16 2004-05-13 Ishikawa Pref Gov レーザ干渉計、及びそれを用いた測定装置
WO2007020738A1 (fr) * 2005-08-16 2007-02-22 Tokyo Seimitsu Co., Ltd. Dispositif de mesure de longueur au laser

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102042804B (zh) * 2009-10-13 2012-12-12 上海微电子装备有限公司 激光干涉仪测量装置和方法
CN114264255A (zh) * 2021-12-28 2022-04-01 中国科学院上海天文台 一种基于干涉位移测量系统的滚转角测量系统和方法
CN114264255B (zh) * 2021-12-28 2023-06-13 中国科学院上海天文台 一种基于干涉位移测量系统的滚转角测量系统和方法

Also Published As

Publication number Publication date
CN101918788A (zh) 2010-12-15
JP2009168709A (ja) 2009-07-30

Similar Documents

Publication Publication Date Title
EP2150770B1 (fr) Capteur optique
EP2163906B1 (fr) Procédé de détection du mouvement d'une sonde de mesure et instrument de mesure
WO2016033766A1 (fr) Système pour mesurer simultanément des erreurs à six degrés de liberté de façon à coupler des lasers à fréquence double par une fibre optique unique
WO2016123812A1 (fr) Appareil et procédé de mesure de linéarité d'interférence hétérodyne à laser faisant appel à une détection à six degrés de liberté
JP3751928B2 (ja) レーザ干渉計、及びそれを用いた測定装置
WO2013013346A1 (fr) Interféromètre à quatre axes et quatre subdivisions
JP5541713B2 (ja) レーザ干渉測長器、それを用いた加工装置および部品の製造方法
US9115973B2 (en) Profile measuring instrument
JP5216465B2 (ja) 変位測定装置、および変位測定方法
US4538911A (en) Three-dimensional interferometric length-measuring apparatus
WO2009090771A1 (fr) Interféromètre laser et instrument de mesure utilisant celui-ci
CN115371587A (zh) 表面形貌测量装置及方法、物体表面高度计算方法
JP2023171867A (ja) 多軸レーザ干渉測長器
CN113701645B (zh) 二自由度外差光栅干涉仪
JP2014098619A (ja) リニアエンコーダ及びワークの加工方法
Xu et al. Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
JPH04351905A (ja) レーザ測長装置を備えたｘｙステージ
JP3045567B2 (ja) 移動体位置測定装置
KR100332035B1 (ko) 단일 파장 레이저 광의 다중패스를 이용한 거리 측정장치 및 방법
CN109341605B (zh) 一种基于激光外差干涉技术的复合测头
JP5149085B2 (ja) 変位計
JP2007285967A (ja) レーザ測長機
JP4994991B2 (ja) 微細形状測定装置
TW202348960A (zh) 用以校準工件平整度之三維準直系統
CN118031793A (zh) 一种自标定高精度扫描白光干涉系统

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200880124842.0

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08792257

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08792257

Country of ref document: EP

Kind code of ref document: A1