JP2013221929A - Three-dimensional measurement method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional measurement method which, if a fulcrum being a rotation center of a probe is shifted in a horizontal direction, calculates an amount of shift of the fulcrum as an error of measurement to correct three-dimensional data in a measurement method for measuring the height and angular variation of the probe.SOLUTION: The three-dimensional measurement method includes a measurement system for detecting a tilt of a stylus 101 and a measurement system for detecting a height of the stylus 101. The measurement system for measuring the height is offset from a fulcrum 106 being the rotation center in a horizontal direction to obtain a distance between the fulcrum and a height measurement position in accordance with the angle and variation in height of the stylus 101, and this distance is confirmed before and after measurement to calculate an amount of shift of the fulcrum 106 in the horizontal direction, and measurement data is corrected.

Description

  The present invention relates to a three-dimensional measurement method and apparatus for correcting an error caused by a probe in a three-dimensional measurement method and apparatus for measuring a hole shape or a side shape of a measurement object.

  As a conventional method for measuring the side surface shape of a measurement object, for example, there is a method of measuring the height and inclination of the measurement object using a He—Ne laser and a semiconductor laser described in Patent Document 1.

  FIG. 4 is a diagram showing a schematic configuration of the measuring instrument 220.

  In FIG. 4, the measuring instrument 220 includes a stylus 201, an angle detection unit 215, an XY stage 210, and a Z movement axis 211. The stylus 201 is in contact with the surface of the object 200 to be measured. The XY stage 210 horizontally moves the DUT 200 to an arbitrary position. The Z movement axis 211 moves the stylus 201 in the height direction. On the XY stage 210, an X-axis measuring mirror 213 and a Y-axis measuring mirror 214 are arranged. In the measuring machine 220, the DUT 200 is moved in the XY direction by the XY stage 210. Next, the stylus 201 is pushed in a horizontal direction by a certain amount with respect to the DUT 200. The angle detection unit 215 measures the angle of the stylus 201 at that time. Thereafter, a measurement operation is performed on the surface of the DUT 200 while controlling the XY stage 210 in the X direction and the Y direction so that the angle is constant. At this time, the X-axis measuring mirror 213 and the Y-axis measuring mirror 214 installed on the XY stage 210 are used to measure the distance by the laser measuring method, whereby the X of the XY stage 210 is measured. And obtain a Y coordinate measurement. Furthermore, by adding the horizontal displacement amount of the stylus 201 based on the angle measured by the angle detection unit 215, the X and Y coordinates of the surface to be measured are measured with high accuracy. In addition, laser length measurement is performed with a mirror 202 connected to a stylus 201 built in the probe 212, and the Z coordinate of the stylus 101 is measured.

  FIG. 5 is a diagram illustrating the structure of the probe 212 and the measurement method of the angle detection unit 215 described in Patent Document 1.

  In the probe 212, the stylus 201 and the swing member 203 are fixed integrally. The stylus 201 is configured to be able to swing laterally about the fulcrum 206 on the mounting table 216 that is integrally fixed to the probe mounting member 222. As a result, when the stylus 201 is pushed in the horizontal direction with respect to the DUT 200, the mirror 202 connected to the stylus 201 is tilted around the X direction and the Y direction in accordance with the displacement in the X direction and the Y direction. On the other hand, the semiconductor laser light 204 is irradiated to the mirror 202 from the semiconductor laser light source 212. Based on the reflected light from the mirror 202, the tilt angle of the mirror 202 is measured by the tilt angle detection unit 205. Further, the height of the mirror 202 is measured by the laser length measurement method using the height measuring laser beam 203. The height measuring laser beam 203 is irradiated so as to be coaxial with the fulcrum 206 on the XY plane in order to prevent an error in the height direction when the mirror 202 is tilted.

JP 2008-292236 A

  However, in the conventional configuration, when there is a large step in the object to be measured or when the surface roughness of the object to be measured 200 is extremely large, a horizontal force is applied to the fulcrum through the stylus, and the position of the fulcrum slightly fluctuates. , Fulcrum misalignment occurred. For this reason, the three-dimensional shape data obtained by measuring the object to be measured has a problem that the measurement accuracy is lowered due to an error caused by a deviation amount due to a minute fluctuation of the fulcrum.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a three-dimensional measurement method and apparatus for calculating a shift amount of a fulcrum that causes a measurement error and correcting three-dimensional shape data.

  In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, there is provided a probe including a stylus mounting member having a stylus at a lower portion and a mirror at an upper portion capable of contacting a surface to be measured of an object to be measured, and one point of the stylus mounting member. A supporting member supported so as to be swingable as a fulcrum; a measuring mirror for measuring a height change and an inclination of the swinging portion; a height measuring unit for measuring the height of the mirror; In a three-dimensional measurement method comprising an inclination measuring unit for measuring inclination, and measuring the measurement surface of the object to be measured,
While the object to be measured and the probe are relatively moved, the laser beam for height measurement and the laser beam for tilt measurement are irradiated to two different points of the mirror, and the tilt between the two points and the height fluctuation value are By measuring the three-dimensional shape data of the measurement surface of the object to be measured, a three-dimensional shape data measurement unit including the inclination measurement unit and the height measurement unit,
The shift amount calculation unit calculates the shift amount of the fulcrum from the inclination between the two points of the three-dimensional shape data obtained by the three-dimensional shape data measurement unit and the height fluctuation value,
A three-dimensional measurement method is provided in which the three-dimensional shape data is corrected by a correction unit using the deviation amount calculated by the deviation amount calculation unit.

According to the third aspect of the present invention, a probe comprising a stylus mounting member having a stylus at the lower part and a mirror at the upper part capable of contacting the surface to be measured of the object to be measured;
A support member supported so as to be swingable about a certain point of the stylus attachment member;
A measuring mirror for measuring a change in height and an inclination of the oscillating portion;
A measuring unit for measuring the height of the mirror; and an inclination measuring unit for measuring the inclination of the mirror, and relatively moving the object to be measured and the probe, and measuring the laser beam and the inclination for measuring the height. The measurement laser beam irradiates two different points of the mirror and measures the inclination between the two points and the height fluctuation value, so that the tertiary of the measurement surface of the measurement object of the measurement object is obtained. A three-dimensional shape data measurement unit for measuring original shape data;
A deviation amount calculation unit for calculating a deviation amount of the fulcrum from the inclination between the two points of the three-dimensional shape data obtained by the three-dimensional shape data measurement unit and the height variation value;
There is provided a three-dimensional measurement apparatus comprising: a correction unit that corrects the three-dimensional shape data using the deviation amount calculated by the deviation amount calculation unit.

  By this method, it is possible to correct the fulcrum deviation of the probe, which has conventionally been a measurement error.

  As described above, according to the three-dimensional measurement method and apparatus of the present invention, the amount of fulcrum misalignment in the X and Y directions is calculated from the change in the tilt and height in the X and Y directions, and the three-dimensional shape data is obtained. By correcting, highly accurate three-dimensional measurement can be performed.

Explanatory drawing of the inclination and height measurement components, calculation part, etc. of the three-dimensional measuring apparatus in 1st Embodiment of this invention. Schematic diagram of the three-dimensional measuring apparatus of FIG. 1A Explanatory drawing regarding the measurement operation | movement of the probe for shape measurement in 1st Embodiment of this invention. The conceptual diagram before the stylus inclination in the probe for shape measurement in 1st Embodiment of this invention The conceptual diagram after the stylus inclination in the probe for shape measurement in 1st Embodiment of this invention Conceptual diagram of a probe for shape measurement when there is no fulcrum misalignment in the first embodiment of the present invention The conceptual diagram of the probe for shape measurement in case the fulcrum shift | offset | difference arises in 1st Embodiment of this invention Schematic diagram of conventional device described in Patent Document 1 Exploded view showing the conventional tilt and height measurement method described in Patent Document 1

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1A is an explanatory diagram of an inclination and height measurement component, a calculation unit, and the like of the three-dimensional measurement apparatus 150 that performs the three-dimensional measurement method according to the first embodiment of the present invention. FIG. 1B is a schematic diagram of the three-dimensional measuring apparatus 150 of FIG. 1A.

  First, the probe 12 of the three-dimensional measuring apparatus 150 will be described. 1A, the probe 12 includes a stylus 101, a stylus mounting member 115, and a mirror 102, and is supported on the mounting table 16 so as to be swingable. A stylus 101 is fixed to the lower end of the stylus mounting member 115. The mirror 102 is fixed to the upper end surface of the cylindrical portion 115 a of the stylus mounting member 115. Therefore, the stylus 101 and the mirror 102 are connected via the stylus mounting member 115.

  The square columnar mounting table 16 passes through the through hole 115b on the side surface of the cylindrical portion 115a of the stylus mounting member 115. The probe fulcrum 106 of the cylindrical portion 115a of the stylus mounting member 115 is inserted into the tapered hole 16a provided on the upper surface of the mounting table 16, and the stylus mounting member 115 is supported by the mounting table 16 in a swingable manner. Therefore, the mounting table 16 functions as an example of a support member that supports the stylus mounting member 115 in a swingable manner.

  In the probe 12 having such a configuration, the mirror 102 is also tilted about the probe fulcrum 106 according to the tilt of the stylus 101.

  As shown in FIG. 1B, the three-dimensional measuring apparatus 150 includes the probe 12 in FIG. 1A, an XY stage 140, and a Z moving shaft 152. At the time of measurement, the lower end of the stylus 101 of the probe 12 is in contact with the side surface (measurement surface) 116a of the measurement object 116. The Z movement axis 152 is a positioning command value in the Z direction (a Z coordinate command value to be measured on the side surface 116a of the object 116 to be measured and a command value commanded from the control unit 141 to the Z movement axis 152). Based on the above, the stylus 101 is moved in the height direction (Z-axis direction) with respect to the stone surface plate 157. A measurement object 116, an X reference mirror 153, and a Y reference mirror 154 are fixed to the measurement object mounting table 160. The object mounting table 160 is moved in the XY direction integrally with the stone surface plate 157 by the XY stage 140 via the XY axis direction drive control device 143 under the control of the control unit 141.

  As will be described later, the laser light emitted from the frequency-stabilized laser light source 110 fixed to the stone surface plate 157 is used as the coordinate measuring laser light in addition to being used as the height measuring laser light 103. The beam is split into a plurality of light beams by a beam splitter (not shown), and used as X-coordinate measuring laser beam 211X (not shown) and Y-coordinate measuring laser beam 211Y. A known laser measurement using a laser beam 211X (not shown) for X-coordinate measurement, a laser beam 211Y for Y-coordinate measurement, an X reference mirror 153 and a Y reference mirror 154 installed on the XY stage 140, etc. By measuring the distance by the method, the X coordinate measurement value and the Y coordinate measurement value of the XY stage 140 are obtained by the X coordinate position coordinate measurement unit 155X and the Y coordinate position coordinate measurement unit 155Y. Further, as will be described later, based on the inclination measured by the inclination angle detection unit 105, the calculation unit 300 calculates and corrects the X coordinate of the measured surface 116 a by using the horizontal displacement amount of the stylus 101 as a deviation amount. And the Y coordinate is measured with high accuracy.

  As a three-dimensional measuring apparatus, in addition to this, a semiconductor laser light source 112, a frequency stabilized laser light source 110, an inclination angle detection unit 105, a height measurement unit 111, an internal memory 108, a calculation unit 300, And a control unit 141. The tilt angle detection unit 105, the height measurement unit 111, the X coordinate position coordinate measurement unit 155X, and the Y coordinate position coordinate measurement unit 155Y function as an example of the three-dimensional shape data measurement unit 301. The inclination angle detection unit 105 functions as an example of an inclination measurement unit. The height measuring unit 111 functions as an example of a height measuring unit.

  The control unit 141 includes a semiconductor laser light source 112, a frequency stabilized laser light source 110, an inclination angle detection unit 105, a height measurement unit 111, an internal memory 108, a calculation unit 300, and position coordinate measurement for X coordinates. It is connected to the unit 155X, the Y coordinate position coordinate measuring unit 155Y, the XY axis direction drive control device 143, and the Z movement axis 152 to control each operation.

  The tilt measurement semiconductor laser beam 104 emitted from the semiconductor laser light source 112 and the height measurement laser beam 103 emitted from the frequency-stabilized laser light source 110 are respectively applied to the mirror 102. A position where the mirror 102 is irradiated with the height measurement laser beam 103 is defined as a height measurement laser beam irradiation position 107. The tilt measurement semiconductor laser beam 104 and the height measurement laser beam 103 are measured with high accuracy by the tilt angle detection unit 105 and the height measurement unit 111, respectively, with respect to the tilt (tilt angle) and height of the mirror 102. doing.

  When the tilt of the mirror 102 changes when the semiconductor laser beam 104 for tilt measurement passes through the half mirror 172 and is reflected by the mirror 102 and enters the tilt angle detection unit 105 via the half mirror 172, the mirror 102 changes. The incident position where the reflected light from the light enters the inclination angle detection unit 105 via the half mirror 172 changes. For this reason, the inclination angle detection unit 105 detects the inclination with high accuracy based on the change in the incident position.

  The height measuring laser beam 103 from the frequency stabilized laser light source 110 is transmitted through the half mirror 171, reflected by the mirror 102, and is incident on the height measuring unit 111 through the half mirror 172. This reflected light includes optical path length change information. On the other hand, the height measuring laser beam 103 from the frequency stabilized laser light source 110 is incident on the height measuring unit 111 via the half mirror 171. The laser light not reflected by the mirror 102 can be used as a reference laser light that does not include optical path length change information. Therefore, the reflected light including the optical path length change information and the reference laser light not including the optical path length change information are caused to interfere with each other by the height measuring unit 111, and the height of the mirror 102 is increased by a known laser measuring method. The length measuring unit 111 detects it with high accuracy.

  On the mirror 102, the height measuring laser beam 103 is arranged at a position offset in the X and Y directions with respect to the fulcrum 106. The semiconductor laser beam 104 for tilt measurement is also arranged at a position offset in the X and Y directions with respect to the fulcrum 106. As an example, the laser beam 103 for height measurement and the laser beam 104 for tilt measurement are irradiated to the mirror 102 diagonally across the fulcrum 106 (the center position of the cross on the mirror 102 in FIG. 1A). More preferably, if the irradiation position of the height measurement laser beam 103 and the irradiation position of the tilt measurement laser beam 104 are equidistant with respect to the fulcrum 106, the arithmetic processing is simplified. As described above, the irradiation positions of the height measurement laser beam 103 and the measurement semiconductor laser beam 104 are arranged diagonally on the mirror 102 with the fulcrum 601 in between, so that the size of the mirror 102 is reduced. This is to minimize it.

  The measured object 116 and the probe 12 include an inclination angle detection unit 105, a height measurement unit 111, an X coordinate position coordinate measurement unit 155X, and a Y coordinate position coordinate measurement unit 155Y that constitute the three-dimensional shape data measurement unit 301. In the relative movement, the three-dimensional shape data of the measurement object 116 is measured and stored in the internal memory 108. Specifically, the X coordinate measurement value and the Y coordinate measurement value of the XY stage 140 obtained by the X coordinate position coordinate measurement unit 155X and the Y coordinate position coordinate measurement unit 155Y, and the height measurement unit 111 are used. The obtained Z coordinate (height) of the probe 12 and the X-direction tilt angle and the Y-direction tilt angle of the stylus 101 obtained by the tilt angle detection unit 105 are stored in the internal memory 108, respectively.

  The data stored in the internal memory 108 is subjected to arithmetic processing by the arithmetic unit 300, and an error caused by the probe 12 can be corrected as will be described later.

  Here, the calculation unit 300 includes a deviation amount calculation unit 302 and a correction unit 303.

  The deviation amount calculation unit 302 calculates the deviation amount of the fulcrum 601 from the inclination between two points and the height fluctuation value, which are the three-dimensional shape data obtained by the three-dimensional shape data measurement unit 301.

  The correction unit 303 uses the deviation amount calculated by the deviation amount calculation unit 302 to measure the X coordinate measurement value and the Y coordinate measurement obtained by the X coordinate position coordinate measurement unit 155X and the Y coordinate position coordinate measurement unit 155Y. Correct the value. As a result, highly accurate three-dimensional measurement can be performed.

  A three-dimensional measurement method using the three-dimensional measurement apparatus according to the above configuration will be described.

  First, at the start of the measurement operation, the control is performed by the control unit 141 so that the tilt of the stylus 101 measured by the tilt angle detection unit 105 is constant, via the XY axial direction drive control device 143. The XY stage 140 holding the measurement object 116 is controlled in the XY directions. Here, “so that the inclination of the stylus 101 measured by the inclination angle detection unit 105 is constant” means that the lower end of the stylus 101 is a certain amount with respect to the measurement surface (side surface) 116 a of the object 116 to be measured. Inclining the stylus 101 with respect to the Z direction so as to press in the horizontal direction (in other words, pressing the lower end of the stylus 101 against the measurement surface (side surface) 116a of the measurement object 116 so that the inclination of the stylus 101 becomes constant). Means. The tilt angle detector 105 measures the tilt of the stylus 101 at that time.

  During the measurement operation, the lower end of the stylus 101 moves along the surface of the measurement surface (side surface) 116a of the measurement object 116 while maintaining this control state (while maintaining the inclination of the stylus 101 constant). As described above, the XY stage 140 is driven via the XY axial direction drive control device 143. By doing so, the XY coordinate measurement value of the XY stage 140, the Z coordinate (height) of the probe 12, and the X direction inclination angle and the Y direction inclination angle of the stylus 101 are combined with the height measuring unit 111 and the inclination angle. Measurement is continuously performed with the detection unit 105, and measurement data is stored in the internal memory 108.

  FIG. 2A is a field diagram in which the operation when measuring the object 116 to be measured with the stylus 101 is viewed from the horizontal direction. As shown in FIG. 2A, by driving the XY stage 140, when the stylus 101 contacts the measurement object 116 and moves along the measurement surface 116a of the measurement object 116, the mirror 102 is centered on the probe fulcrum 106. The slope of changes. At this time, the height of the mirror 102 changes in proportion to the horizontal distance from the mirror center to the height measurement laser light irradiation position 107 and the inclination of the mirror 102.

  2B are a conceptual diagram when the probe 12 with no fulcrum misalignment and the stylus 101 not inclined is viewed downward in the Z direction and a conceptual diagram when viewed from the Y direction. 2C are a conceptual diagram when the probe 12 with no fulcrum misalignment and the stylus 101 tilted is viewed downward in the Z direction, and a conceptual diagram when viewed from the Y direction and the X direction, respectively. is there. Here, symbols are defined as follows. In FIG. 2C, the inclination (inclination angle) is exaggerated and drawn, but the inclination in actual measurement is a very small value of 60 seconds (s) at the maximum.

  Lx: X-direction distance (design value) from the laser beam irradiation position 107 for height measurement on the mirror 102 to the position of the fulcrum 106.

  Ly: Y-direction distance (design value) from the laser beam irradiation position 107 for height measurement on the mirror 102 to the fulcrum 106 position.

  Ls: The length (design value) of the stylus 101 from the measurement point to the fulcrum 106.

  ΔX (n): A distance in the X direction from the measurement point (contact point between the lower end of the stylus 101 and the side surface (measurement surface) 116a of the object 116) to the fulcrum 106 when the stylus is tilted.

  ΔY (n): Y direction distance from the measurement point to the fulcrum 106 when the stylus is tilted.

  Θx (n): the amount of inclination of the mirror 102 around the X axis.

  Θy (n): the amount of inclination of the mirror 102 around the Y axis.

These values have the following relational expression (1).

ΔX (n) = Ls · sin θy (n)
ΔY (n) = Ls · sin θx (n)
(1)
Furthermore, since the inclination of the mirror 102 is sufficiently small as 60 seconds (s) at the maximum, the above equation (1) is obtained by using an approximate expression of a minute angle for the trigonometric function.

ΔX (n) = Ls · θy (n)
ΔY (n) = Ls · θx (n)
(2)

The error due to the inclination of the stylus 101 can be expressed as the above equation (2).

  In addition, the following is defined as a new code.

X ₁ (n): X-coordinate measurement value of the XY stage 140 obtained by the X-coordinate position coordinate measurement unit 155X by a laser measurement method using the X-axis measuring mirror 153 installed on the XY stage 140.

Y ₁ (n): Y coordinate measurement value of the XY stage 140 obtained by the Y coordinate position coordinate measurement unit 155Y by a laser measurement method using the Y axis measuring mirror 154 installed on the XY stage 140.

Z ₁ (n): Z coordinate measurement value (height) of the stylus 101 obtained by the height measuring unit 111 by a laser measurement method using the mirror 102.

(X ₁ (n), Y ₁ (n), Z ₁ (n), θx () are obtained by adding the inclination amounts θx (n) and θy (n) measured by the inclination angle detector 105 to these values. n), θy (n)) as the measured values of the three-dimensional shape data, the X coordinate position coordinate measuring unit 155X, the Y coordinate position coordinate measuring unit 155Y, the height measuring unit 111, and the inclination angle detecting unit 105 And stored in the internal memory 108, respectively.

  3A and 3B, a correction amount calculation method performed by the arithmetic unit 300 will be described based on data stored in the internal memory 108 when a fulcrum shift occurs as described in the related art. Here, the following code is newly defined.

  Gx (n): A shift amount of the fulcrum 106 in the X direction.

  Gy (n): A shift amount of the fulcrum 106 in the Y direction.

  Δh (n): difference between the Z coordinate measured by the mirror 102 and the positioning command value in the Z direction.

  3A and 3B are diagrams in the case where only the deviation in the X direction occurs, but in reality, a similar state also occurs in the Y direction.

  3A and 3B, the amount of displacement is exaggerated and drawn extremely large, but actually, as shown in FIG. 2A, the fulcrum 106 is in the tapered hole 16a provided in the mounting table 16, and the amount of displacement is shown. Is on the order of several tens of μm. Further, when the deviation occurs, the fluctuation in the Z direction of the mirror 102 is so small that it can be ignored.

  At this time, the distance in the X direction from the laser beam irradiation position 107 for height measurement to the position of the fulcrum 106 is Lx + Gx (n), and the change amount Δh (n) of the height of the mirror 102 has the maximum inclination of the mirror 102. However, since it is sufficiently small as 60 seconds (s), it can be approximated by the following equation (3).

Δh (n) = (Lx + Gx (n)) · tan θy (n) + (Ly + Gy (n)) · tan θx (n)
(3)

In addition, when using an approximation formula of small angles for trigonometric functions,

Δh (n) = (Lx + Gx (n)) · θy (n) + (Ly + Gy (n)) · θx (n)
(4)

It can be expressed.

In this equation (4), the height change amount Δh (n) is obtained from the measured value of the height measuring unit 111 and the command value of the Z moving shaft 152, and the inclination amounts θx (n) and θy (n) are obtained. Since it is measured by the inclination angle detection unit 105, it is known. The distances Lx and Ly are also known because they are design values. However, the deviation amount Gx (n) and the deviation amount Gy (n) are unknown due to the influence of the fulcrum deviation or the assembly error. Therefore, the change amount Δh (n), the inclination amount θx (n), and the inclination amount θy (n) are two different points, that is, the points (Δh (n ₁ ), θx (n ₁ ), θy (n ₁ )). , And at the points (Δh (n ₂ ), θx (n ₂ ), θy (n ₂ )), the amount of deviation Gx (n ₁ ) and the amount of deviation are expressed by the following equations (5) and (6). Gy (n ₁ ) can be obtained by the deviation amount calculation unit 302.

・・・・・・（５）

(5)

(6)

Thus, the deviation amount Gx (n ₁ ) and the deviation amount Gy (n ₁ ) are calculated by the deviation amount calculation unit 302. As described above, the deviation amount Gx (n) and the deviation amount Gy (n) can be calculated by the deviation amount calculation unit 302 from two arbitrary points.

In addition, as a new code,

X ₂ (n): the X coordinate of the measurement surface 116a of the measurement object 116,
Y ₂ (n): Y coordinate of the measurement surface 116a of the measurement object 116,
Z ₂ (n): Z coordinate of the measurement surface 116a of the measurement object 116,

Define These values (X ₂ (n), Y ₂ (n), Z ₂ (n)) are stored in the internal memory 108 as three-dimensional shape data (X ₁ (n), Y ₁ (n), Z ₁ (n), θx (n), θy (n)) and ΔX (n), ΔY (n), Δh (n), Gx (n), Gy (n) calculated by the deviation amount calculation unit 302 Then, the following equation (7) is established.

X ₂ (n) = X ₁ (n) −ΔX (n) + Gx (n)
Y ₂ (n) = X ₁ (n) −ΔY (n) + Gy (n)
Z ₂ (n) = Z ₁ (n) −Δh (n)
(7)

By correcting the equation (7) by the correction unit 303, correction by the correction unit 303 is performed.

In this manner, the shift amount calculation unit 302 calculates the fulcrum shift amount in the X direction and the Y direction from the changes in the tilt and height in the X and Y directions, and the correction unit 303 corrects the three-dimensional shape data. The XYZ coordinates (X ₂ (n), Y ₂ (n), Z ₂ (n)) of the measurement surface 116a of the measurement object 116 can be obtained with high accuracy. Therefore, it is possible to measure the measurement surface 116a of the measurement object 116 with high accuracy by the three-dimensional measurement apparatus 150 of the first embodiment.

  The above correction is performed by the deviation amount calculation unit 302 and the correction unit 303 based on the three-dimensional shape data stored in the internal memory 108 after the measurement by the three-dimensional shape data measurement unit 301 is completed. Perform correction processing. Further, in the correction using ΔX (n), ΔY (n), and Δh (n), the shift amount is calculated by the shift amount calculation unit 302 for each measurement point, and the correction unit 303 performs the correction. However, in the correction using the deviation amount Gx (n) and the deviation amount Gy (n), since the frequency of occurrence of the fulcrum deviation is low, it is not necessary to calculate the deviation amount for all measurement points by the deviation amount calculation unit 302. It is also possible to calculate a deviation amount at a certain measurement point interval by the deviation amount calculation unit 302 and to correct the deviation by the correction unit 303. Alternatively, the deviation amount calculation unit 302 sets the deviation amount in the section as Gx (n) and the deviation amount as Gy (n) in the average value of the deviation amount in a certain section, and the correction unit 303 performs the correction. Also good. It is also possible to calculate the deviation amount Gx (n) and the deviation amount Gy (n) by the deviation amount calculation unit 302 and correct the deviation amount in real time by the correction unit 303 every time a measurement point is captured during measurement.

  In the first embodiment, the tilt measuring laser beam 104 is arranged so as to be irradiated diagonally with respect to the height measuring laser beam 103 with the fulcrum 601 interposed therebetween. However, the tilt measuring laser beam 104 can be applied to any position other than the fulcrum position on the mirror 102. In principle, even if the mirror 102 is arranged on the X axis or the Y axis, new inclinations θx ′ (n) and θy ′ (n) rotated by a certain angle from the inclinations θx (n) and θy (n). The coordinate system can be calculated inside the software (for example, the tilt angle detection unit 105). Using the data calculated in this way, it is possible to define a shift amount calculation unit 302 with respect to the x ′ and y ′ directions of the new coordinate system. Is possible. An optical system for detecting the tilt of the mirror 102 can be arranged at any position on the mirror 102. In order to minimize the mirror size, a fulcrum where the size of the probe 101 is the smallest is sandwiched. They are arranged diagonally.

  According to the above configuration, in the probe 12 of the three-dimensional measuring apparatus 150 that measures the displacement of the stylus 101 as the displacement of the tilt and the height of the mirror 102 connected to the stylus 101, the stylus is connected to the stylus 101 by the mirror 102. 101 is measured by the height measuring unit 111 and the tilt angle detecting unit 105, and the horizontal shift amount of the fulcrum 106 serving as the rotation center is calculated by the shift amount calculating unit 302 from the two values. In addition, a three-dimensional measurement method and apparatus for correcting the coordinate measurement value by the correction unit 303 according to the amount of deviation are provided. According to such a configuration, the shift amount calculation unit 302 calculates the fulcrum shift amount in the X direction and the Y direction from the changes in the tilt and height in the X and Y directions, and the three-dimensional shape data is corrected by the correction unit 303. By doing so, highly accurate three-dimensional measurement can be performed.

  In addition, it can be made to show the effect which each has by combining arbitrary embodiment or modification of the said various embodiment or modification suitably.

  The three-dimensional measurement method and apparatus of the present invention have an optical system that calculates and corrects errors caused by a probe, and can be applied to high-precision shape measurement of side surfaces along the vertical direction of a lens barrel or gear.

DESCRIPTION OF SYMBOLS 12 Probe 16 Mounting base 16a Tapered hole 101 Stylus 102 Mirror 103 Height measurement laser beam 104 Semiconductor laser beam 105 Inclination angle detection part 106 Support point 107 Height measurement laser beam irradiation position 108 Internal memory 110 Frequency stabilization laser light source 111 Height Length measuring section 112 Semiconductor laser light source 115 Stylus mounting member 115a Cylindrical section 115b Through hole 116 Object to be measured 116a Surface to be measured 140 XY stage 141 Controller 143 XY axis direction drive controller 150 Three-dimensional measuring apparatus 152 Z movement axis 153 X Reference mirror 154 Y reference mirror 155X X coordinate position coordinate measurement unit 155Y Y coordinate position coordinate measurement unit 157 Stone surface plate 160 Object mounting table 171 Half mirror 172 Half mirror 211 Y Y coordinate measurement The light 300 arithmetic unit 301 three-dimensional shape data measuring unit 302 shift amount calculation unit 303 corrects unit

Claims (3)

A probe having a stylus mounting member having a stylus at the lower part and a mirror at the upper part capable of contacting the surface to be measured of the object to be measured, and a support supported so as to be swingable with one point of the stylus mounting member as a fulcrum A member, a measuring mirror for measuring the height change and tilt of the swinging unit, a height measuring unit for measuring the height of the mirror, and an tilt measuring unit for measuring the tilt of the mirror. In the three-dimensional measurement method for measuring the measurement surface of the measurement object,
While the object to be measured and the probe are relatively moved, the laser beam for height measurement and the laser beam for tilt measurement are irradiated to two different points of the mirror, and the tilt between the two points and the height fluctuation value are By measuring the three-dimensional shape data of the measurement surface of the object to be measured, a three-dimensional shape data measurement unit including the inclination measurement unit and the height measurement unit,
The shift amount calculation unit calculates the shift amount of the fulcrum from the inclination between the two points of the three-dimensional shape data obtained by the three-dimensional shape data measurement unit and the height fluctuation value,
A three-dimensional measurement method, wherein the three-dimensional shape data is corrected by a correction unit using the deviation amount calculated by the deviation amount calculation unit.   2. When measuring the three-dimensional shape data, the height measuring laser beam and the tilt measuring laser beam are applied to the two points diagonally across the fulcrum of the mirror. The three-dimensional measuring method described. A probe having a stylus mounting member having a stylus at the lower part and a mirror at the upper part that can contact the surface to be measured of the object to be measured;
A support member supported so as to be swingable about a certain point of the stylus attachment member;
A measuring mirror for measuring a change in height and an inclination of the oscillating portion;
A measuring unit for measuring the height of the mirror; and an inclination measuring unit for measuring the inclination of the mirror, and relatively moving the object to be measured and the probe, and measuring the laser beam and the inclination for measuring the height. The measurement laser beam irradiates two different points of the mirror and measures the inclination between the two points and the height fluctuation value, so that the tertiary of the measurement surface of the measurement object of the measurement object is obtained. A three-dimensional shape data measurement unit for measuring original shape data;
A deviation amount calculation unit for calculating a deviation amount of the fulcrum from the inclination between the two points of the three-dimensional shape data obtained by the three-dimensional shape data measurement unit and the height variation value;
A three-dimensional measurement apparatus comprising: a correction unit that corrects the three-dimensional shape data using the deviation amount calculated by the deviation amount calculation unit.

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