JP2004325120A - Probe scanning type shape-measuring apparatus provided with straightness correction function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make measurable an object to be measured 1 with high measuring accuracy even if the object 1 is long and a linearly advancing mechanism to be a reference also becomes long in a probe scanning type shape-measuring apparatus. <P>SOLUTION: The results of measurement on scanning straightness measured by a probe scanning device are corrected by a straightness correction device, on the basis of variable components in X-axis and Y-axis directions on a linearly advancing stage detected by a mirror optical device for error detection; a location in a Z-axis direction; and rotational variations each on the X-axis, the Y-axis, and the Z-axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a precision measuring device that measures a shape such as surface roughness by scanning with a measurement probe head, and in particular, a straightness correction function for measuring the scanning straightness of a measurement probe head and correcting (calibrating) the measurement result. The present invention relates to a probe scanning type shape measuring instrument provided with
[0002]
[Prior art]
A conventional probe scanning type shape measuring device measures a shape by scanning a probe based on a straight moving mechanism manufactured in advance with high accuracy (for example, see Patent Documents 1 to 3).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 5-31538 [Patent Document 2]
Japanese Patent Application Laid-Open No. H11-211427 [Patent Document 3]
JP 2001-141443 A
[Problems to be solved by the invention]
In the conventional probe scanning type shape measuring device, when the object to be measured is short, the reference straight moving mechanism can be short, so that high measurement accuracy can be maintained. However, when the object to be measured is long, it is difficult to manufacture a linear movement mechanism as a reference with high accuracy. Even if it can be manufactured, it is difficult to hold it, and in any case at present, it is very difficult to measure the shape of a long measurement target with high accuracy.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above conventional problems and to measure the shape of a long measuring object with high accuracy in a probe scanning type shape measuring instrument.
[0006]
By the way, the present inventor has already carried out the proposal of the straightness measurement theory of the rectilinear stage and the measurement experiment of the rotation error 3 component among the straightness components, and said, Tenjinbayashi, Furukawa, Optics Japan2000 Lecture Proceedings pp331-332 and "Linear Stage Straightness Measurement-Rotation Error Component Measurement Experiment-Tenjinbayashi Optics Japan2001 Lecture Proceedings pp153-154".
[0007]
However, this is merely a technique for measuring the straightness of the straight traveling stage. The inventor of the present invention has been engaged in research and development of a probe scanning type shape measuring instrument capable of measuring the shape of a long measurement target with high accuracy. In this case, they came to think that the straightness of the probe could be measured.
[0008]
Therefore, the present invention measures the straightness of the scanning object at the same time while scanning the measuring probe head to measure the shape of the workpiece 1, and corrects the shape measurement data with the obtained straightness data, thereby achieving high accuracy. An object of the present invention is to realize a probe scanning shape measuring instrument capable of measuring the shape of a long measurement object with high accuracy without a reference rectilinear mechanism.
[0009]
[Means for Solving the Problems]
According to the present invention, in order to solve the above-described problems, a straight-moving stage is provided on a straight-moving guide so as to be able to travel in the Z-axis direction, and a measurement probe head is provided on the straight-moving stage. A probe scanning type shape measuring instrument having a straightness correction function in which a straightness error detecting optical device and a shape analyzing device are provided outside a straight-moving stage, wherein a probe-scanning shape measuring device is provided between the measuring probe head and the surface of the workpiece. The optical device for measuring the distance and detecting the straightness error on the straight-moving stage has a corner cube mirror and a parallel two-sided mirror, and the corner cube mirror translates the straight-moving stage in the X-axis and Y-axis directions. The parallel dihedral mirror is for detecting an error component and a position of the rectilinear stage in the Z-axis direction. For detecting the minutes, detecting the straightness of scanning of the measuring probe head, and detecting the measured distance by the error detecting optical device in the X-axis and Y-axis directions relating to the rectilinear stage. To measure the shape with high accuracy by correcting with the shape analysis device based on the error variation component, the position in the Z-axis direction, and the rotational error components around the X-axis, around the Y-axis, and around the Z-axis. The present invention provides a probe scanning type shape measuring instrument having a straightness correction function.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a probe scanning type shape measuring instrument having a straightness correction function according to the present invention will be described below based on examples with reference to the drawings.
[0011]
FIG. 1 is a view for explaining the concept of a probe scanning type shape measuring instrument having a straightness correction function according to the present invention. The rectilinear stage 4 is provided so as to be able to run on the rectilinear guide 5, and the measuring probe head 2 is provided on the rectilinear stage 4. The straight stage 4 is run to measure the distance between the object 1 to be measured and the measurement probe head 2, and at the same time, the scanning error of the straight stage 4 is measured and corrected by the straightness measuring unit 27, and the measurement is performed. The surface shape of the object 1 is measured with high accuracy.
[0012]
When the rectilinear stage 4 moves a long distance along the linear guide 5, a straightness error occurs. The present invention is a probe scanning shape measuring instrument having a straightness correction function for measuring a scanning error of the straight moving stage 4 and correcting a straightness error based on the measured value.
[0013]
FIG. 2 is a diagram showing a straightness component of the straight traveling stage 4 with reference to XYZ coordinates. The traveling direction of the rectilinear stage 4 is defined as the Z direction, and among the directions orthogonal to the traveling direction, the horizontal direction is defined as the X direction, and the vertical direction is defined as the Y direction. The straightness errors indicated on the basis of the XYZ coordinates are the following five components that are translation in the horizontal and vertical directions orthogonal to the traveling direction and rotation around the XYZ axis.
[0014]
The translation components of the straightness error are ΔX of the horizontal component and ΔY of the vertical component. The rotation components of the straightness error are rotation で (pitch) around the X axis, rotation η (yaw) around the Y axis, and rotation ζ (roll) around the Z axis. In the present invention, all of these straightness errors are measured, and the measurement value by the measurement probe head 2 is corrected as described above.
[0015]
(Example)
FIG. 3 is a view for explaining an embodiment of a probe scanning type shape measuring instrument having a straightness correction function according to the present invention. This probe scanning type shape measuring instrument has a measuring probe head 2 and a straightness measuring unit 27. In FIG. 3, a probe scanning type shape measuring instrument having a straightness correction function according to the present invention is provided with a straight traveling stage 4 on a straight traveling guide 5 so as to be able to travel. A detection optical unit 26 (see FIG. 1) is provided.
[0016]
The straightness measuring unit 27 includes a straightness error detecting optical unit 26, a straight-moving stage position detecting interferometer 10, a laser beam generating unit 23, a laser beam detecting unit 24, a laser beam position detecting unit 25, and a shape analyzing device 28. Become.
[0017]
Here, the shape analyzer 28 calculates the straightness from the output signals of the laser beam detection unit 24 and the laser beam position detection unit 25 and corrects the distance between the measurement probe head 2 and the surface of the workpiece 1 for measurement. It is a calculator that calculates the shape of the object surface.
[0018]
The measurement probe head 2 is attached to a straightness error detection optical unit 26 in the Y-axis direction, and includes, for example, a measurement probe head 2 (an optical measurement probe head for detecting the reflection intensity of emitted light). Means are employed. With this measurement probe head 2, the distance between the measurement probe head 2 and the surface of the measurement object 1 can be measured.
[0019]
By moving the rectilinear stage 4 and scanning the surface of the measurement object 1 with the measurement probe head 2, the distance to the surface of the measurement object 1 is continuously measured, and the measurement object 1 to be measured is measured based on the measured value. Is measured.
[0020]
As shown in FIG. 3, the straightness error detection optical unit 26 shown in FIG. 1 includes a translation error and position detection corner cube mirror 7 and two sets of parallel dihedral mirror units 13 for detecting rotation angle errors.
[0021]
In the apparatus of the present invention, the following detectors (1) to (4) are provided as detectors.
(1) Laser beam position detector 8 for detecting translation errors
(2) Laser detector 11 for linear stage position detection
(3) Vertical parallel two-sided mirror reflected laser beam position detector 14
(4) Horizontal parallel two-sided mirror reflected laser beam position detector 16
[0022]
FIG. 4 is a block diagram for explaining the principle of a probe scanning type shape measuring device provided with the straightness correcting device according to the present invention. According to FIG. 4, the distance between the measurement object and the probe head is measured by the measurement probe light 3 and the measurement probe head 2, and probe measurement data is obtained.
[0023]
With respect to the probe measurement data, the translation error obtained by the translation error detection laser beam position detector 8 and the vertical parallel dihedral mirror reflected laser beam position detector 14 and the horizontal parallel dihedral mirror reflected laser beam position detector 16 are used. Probe rotation straightness correction (calibration) is performed from the obtained rotation angle error and the laser detector 11 for detecting the straight-moving stage position, and true shape data is obtained.
[0024]
FIGS. 5 and 6 are diagrams for explaining the action of the mirror on the laser beam for detecting the five components of the straightness error of the rectilinear stage 4, respectively. The detection of each straightness error component will be described with reference to FIGS. I do.
[0025]
The corner cube mirror unit 7 for translation error and position detection has a corner cube mirror 18. 5A and 5B are a plan view and a side view of the corner cube mirror 18, respectively. The corner cube mirror 18 is for detecting the translation error of the rectilinear stage 4 and the position of the rectilinear stage, and uses a well-known corner cube mirror.
[0026]
The translation error and position detection corner cube mirror unit 7 receives the translation error detection laser beam 6 by the corner cube mirror 18 and detects the reflected light by the translation error detection laser beam position detector 8 for measurement. The horizontal and vertical translation errors ΔX and ΔY of the probe head 2 are detected.
[0027]
Further, the corner cube mirror unit 7 for translation error and position detection divides the laser beam 9 for linear stage position detection into two laser beams by the beam splitter of the interferometer 10 for linear stage position detection, and splits one of the laser beams. The light is received by the corner cube mirror 18, and the reflected light is received by the laser detector 11 for detecting the position of the rectilinear stage through the interferometer 10 for detecting the position of the rectilinear stage.
[0028]
The other laser beam is reflected by a plane mirror inside the interferometer 10 for detecting the position of the rectilinear stage, returns to the original optical path, and overlaps with the one laser beam to form interference light. Is received at. The position of the measurement probe head in the Z direction is detected by counting the number of stripes of the interference light. In this manner, the translation errors ΔX, ΔY and the position Z of the translation stage 4 can be detected by the translation error detection laser beam position detector 8 and the translation stage position detection laser detector.
[0029]
The parallel dihedral mirror unit 13 for detecting a rotation angle error has two sets of parallel dihedral mirrors. FIGS. 6A and 6B are a plan view and a side view of the two-sided mirror, respectively. Specifically, the two sets of parallel dihedral mirrors are the first and second mirrors 19a and 19b and the first and second mirrors 20a and 20b, respectively. Having. These two sets of parallel dihedral mirrors detect rotation fluctuation around the X axis (pitch), rotation fluctuation around the Y axis (yaw), and rotation fluctuation around the Z axis (roll).
[0030]
The parallel dihedral mirror unit 13 for detecting a rotation angle error receives the laser beam 12 incident on the vertical parallel dihedral mirror for detecting the rotation angle error and the laser beam 15 incident on the horizontal parallel dihedral mirror for detecting the rotation angle error. a) As shown in (b), after being reflected by the vertical parallel two-sided mirrors 20a and 20b and the horizontal parallel two-sided mirrors 19a and 19b, the vertical parallel two-sided mirror incident laser beam position detector 14 and the horizontal parallel two-sided mirror It is detected by a mirror incident laser beam position detector 16. Thus, rotation fluctuation (pitch) in a vertical plane around the X axis, rotation fluctuation (yaw) around the Y axis, and rotation fluctuation (roll) around the Z axis are detected.
[0031]
The linear stage position detecting interferometer 10 has a corner cube mirror 18, receives the linear stage position detecting laser beam 9, and detects the interference light with the linear stage position detecting laser beam position detector 11. The position of the measurement probe head 2 in the Z direction is detected.
[0032]
As described above, the embodiment of the probe scanning type shape measuring device provided with the straightness correction device according to the present invention has been described based on the embodiments. However, the present invention is not limited to such embodiments, and claims are not limited thereto. It goes without saying that there are various embodiments within the scope of the technical matters described in the above.
[0033]
【The invention's effect】
According to the present invention having the above-described configuration, in the probe scanning type shape measuring device, it is possible to perform measurement with high measurement accuracy even when the object to be measured is long and the reference linear movement mechanism is long.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a basic concept of the present invention.
FIG. 2 is a diagram illustrating a translation error component and a rotation error component that cause an error in detection by a measurement probe head of the probe scanning shape measuring instrument according to the present invention.
FIG. 3 is a view for explaining an embodiment of a probe scanning type shape measuring device provided with the straightness correction device according to the present invention.
FIG. 4 is a view for explaining the principle of measurement by the probe scanning type shape measuring instrument of the embodiment.
FIG. 5 is a diagram illustrating a main part of a probe scanning type shape measuring device according to the embodiment and an operation thereof.
FIG. 6 is a diagram illustrating a main part of a probe scanning type shape measuring device according to the embodiment and an operation thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Measurement object 2 Measurement probe head 3 Measurement probe light 4 Straight stage 5 Straight guide 6 Laser beam 7 for translation error detection Corner cube mirror unit 8 for translation error and position detection Laser beam position detector 9 for translation error detection 9 Straight stage position detection Laser beam 10 for linear stage position detection interferometer 11 Laser detector for linear stage position detection 12 Vertical parallel two-sided mirror incident laser beam for rotation angle error detection Parallel two-sided mirror unit for rotation angle error detection 14 Vertical parallel two sided Mirror reflected laser beam position detector 15 Horizontal parallel two-sided mirror incident laser beam 16 for detecting rotation angle error Horizontal parallel two-sided mirror reflected laser beam position detector 17 Corner cube mirror vertex 18 Corner cube mirror 19a One of the horizontal parallel two-sided mirror Mirror 19b Horizontal parallel double mirror Second mirror 20a First parallel mirror 20b First mirror 20b Second mirror of vertical parallel two-sided mirror 23 Laser beam generation unit 24 Laser beam detection unit 25 Laser beam position detection unit 26 For straightness detection Optical unit 27 Straightness measuring unit 28 Shape analyzer

Claims (1)

A rectilinear stage is provided on the rectilinear guide so as to be able to travel in the Z-axis direction, a measuring probe head is provided on the rectilinear stage, and an optical device for detecting a straightness error on the rectilinear stage and outside the rectilinear stage. And a probe scanning type shape measuring device having a straightness correction function provided with a shape analysis device,
An optical device for measuring a straightness error on the rectilinear stage, which measures a distance between the measurement probe head and the surface of the object, has a corner cube mirror and a parallel two-sided mirror, and the corner cube mirror Is for detecting a translation error component of the rectilinear stage in the X-axis and Y-axis directions and a position of the rectilinear stage in the Z-axis direction. The parallel dihedral mirror is provided around the X-axis, the Y-axis, and This is for detecting each rotation error component around the Z axis, detecting the scanning straightness of the measurement probe head, and measuring the measurement distance by the error detection optical device. The correction is performed by the shape analysis device based on the translation error components in the X-axis and Y-axis directions, the position in the Z-axis direction, and the rotation error components around the X-axis, around the Y-axis, and around the Z-axis. Probe scanning shape measuring device having a straightness correction function and measuring a shape with high accuracy Te.

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