JP2014132252A - Measurement method, measurement device and article fabrication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that is advantageous for highly accurately measuring a position of a measurement part on a measured plane.SOLUTION: The measurement method measuring a position of a measurement part on the basis of angle information indicative of an emission angle of light upon emitting the light onto the measurement part on a measured plane from an emission part emitting the light onto the measured plane and distance information indicative of a distance between the measurement part and the emission part includes: a measurement step that measures an average value of a distance between each of a plurality of measurement points in an area including the measurement part and the emission part; a calculation step that, assuming that design data on the measured plane is used and the measured plane is formed in conformity to a design value, calculates a difference between the distance between the measurement part and the emission part and the average value of the distances between the plurality of measurement points and the emission part on the basis of the assumption as a first offset value; a calibration step that calibrates the average value of the distance measured in the measurement step with the first offset value; and a decision step that uses the value calibrated with the first offset value as the distance information, and decides a position of the measurement point.

Description

  The present invention relates to a measurement method, a measurement apparatus, and a method for manufacturing an article.

  In a measurement apparatus including an emission unit that emits light toward a test surface, there is a measurement method that measures the shape of the test surface by changing the emission angle of light emitted from the emission unit. In such a measurement method, light is emitted from the emission part toward the measurement location on the surface to be measured, angle information indicating the emission angle of the light at that time, and a distance indicating the distance between the measurement location and the emission portion Measure information. The position (height) of the measurement location can be acquired from the angle information and the distance information, and the shape of the test surface can be measured by performing such measurement at a plurality of measurement locations.

  However, the distance information measured by irradiating the measurement location with light from the emitting portion may cause an error due to speckle noise generated by light scattering on the surface to be measured. Thus, if there is an error in the distance information, it becomes difficult to measure the shape of the test surface with high accuracy. Therefore, there is a method in which the distance between each measurement point and the emission part is measured at a plurality of measurement points in the region including the measurement point, and the average value of the distances measured at each measurement point is used as distance information at the measurement point. It has been proposed (see Patent Document 1). By using this method, errors that occur in distance information due to speckle noise or the like can be reduced.

JP 2010-223950 A

  In the measurement method described in Patent Document 1, in order to reduce an error in distance information due to speckle noise or the like, an average value of distances measured at a plurality of measurement points in a region including the measurement point is calculated at the measurement point. Used as distance information.

  In recent years, it has been demanded to measure a test surface having various shapes such as a test surface having a large curvature with high accuracy. However, with the measurement method described in Patent Document 1, even if the error in distance information due to speckle noise or the like can be reduced, the average value of the distances measured at a plurality of measurement points and the distance information at the measurement points An error occurs in the meantime. If such an error occurs, it may be difficult to measure the shape of the test surface with high accuracy.

  Therefore, an object of the present invention is to provide a technique advantageous in measuring the position of a measurement location on a surface to be measured with high accuracy.

  In order to achieve the above object, a measurement method according to one aspect of the present invention provides light emission when light is emitted from a light emitting portion that emits light toward a test surface to a measurement location on the test surface. A measurement method for measuring the position of the measurement location based on angle information indicating an angle and distance information indicating a distance between the measurement location and the emission part, and a plurality of methods in a region including the measurement location Assuming that the test surface is formed according to the design value, using the measurement process of measuring the average value of the distance between each of the measurement points and the emitting portion, and the design data of the test surface, In the assumption, a calculation step of calculating a difference between a distance between the measurement location and the emission portion and an average value of the distances between the plurality of measurement points and the emission portion as a first offset value; and The average value of the measured distance is calculated as the first offset. Using a calibration step to calibrate a set value, the calibration value by the first offset value as the distance information includes a determination step of determining the position of the measurement point, it is characterized.

  According to the present invention, for example, it is possible to provide a technique advantageous in measuring the position of a measurement location on a surface to be measured with high accuracy.

It is a figure which shows the measuring apparatus of 1st Embodiment. It is a flowchart which shows the measuring method which measures the shape of a to-be-tested surface. It is a figure which shows the output angle (theta) and the distance L with respect to the position of a scanning direction. It is a figure which shows the profile of output angle (theta) 'with respect to the position of a scanning direction, and the profile of distance L'. Is a diagram showing an emission angle theta _{n 'and} the distance L _n' with respect to the scanning direction of the position. Is a diagram showing an emission angle theta _{n 'and} the distance L _n' with respect to the scanning direction of the position.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member thru | or element, and the overlapping description is abbreviate | omitted. Moreover, in each figure, the direction orthogonal to each other on the test surface is defined as the X direction and the Y direction, respectively, and the direction orthogonal to the test surface is defined as the Z direction.

<First Embodiment>
A measuring apparatus 100 according to a first embodiment of the present invention will be described with reference to FIG. The measuring apparatus 100 includes a measuring system 1 including an emitting unit 2 having a light projecting / receiving unit 3 and a scanning unit 4, a distance measuring unit 5, an emitting angle measuring unit 6, a calibration unit 7, and a determining unit 8. ing. The measurement system 1 includes a light emission angle θ (angle information) when light is emitted from the emission unit 2 toward the measurement location on the test surface 10 of the test object 9, and the measurement location and the emission unit 2. The position (for example, Z direction) of the measurement location is measured based on the distance (distance information). Then, the measurement system 1 scans the light on the surface to be measured by changing the emission angle θ of the light emitted from the emission unit 2, and positions (Z direction) for a plurality of measurement points on the surface to be measured. By measuring, the shape of the test surface can be measured.

  The light projecting / receiving unit 3 of the emitting unit 2 can include, for example, a light source 3a, a light receiving element 3b, a beam splitter 3c, and an interference light generating unit 3d. The light source 3a is composed of, for example, a laser diode, and generates a beam-shaped laser beam (light). The generated light has its optical path changed by the beam splitter 3 c and is emitted toward the test surface 10 through the scanning unit 4. The light receiving element 3b is a plurality of photodiodes and arranged so as to be able to measure the shape of the test surface in the direction in which light is scanned on the test surface (the direction of changing the emission angle (X direction in the first embodiment)). Of pixels. Each pixel is composed of, for example, a CCD (charge coupled device) sensor, a CMOS (complementary metal oxide semiconductor) sensor, or the like. The scanning unit 4 of the emitting unit 2 includes, for example, a galvanometer mirror. The galvanometer mirror rotates by an amount corresponding to the drive voltage supplied thereto, and can change the emission angle of the light generated by the light source 3a, for example, along the X direction. Thereby, the light which passed the scanning part 4 can be scanned along a X direction on a to-be-tested surface. The scanning unit 4 supplies the light emission angle (the angle of the galvanometer mirror) to the emission angle measurement unit 6 as an electrical signal. Here, the scanning unit 4 of the first embodiment uses a Gabarno mirror as an element for changing the light emission angle, but is not limited thereto, and for example, an acousto-optic element, a polygon mirror, or a MEMS may be used. .

The light reflected by the test surface 10 enters the light projecting / receiving unit 3 again via the scanning unit 4, passes through the beam splitter 3c, and enters the interference light generating unit 3d. Interference light generating section 3d includes, for example, ₁ and the first polarizer 3d, a birefringent crystal 3d _2, and a second polarizer 3d _3. The light that has passed through the first polarizer 3d ₁ is separated into light having orthogonal polarization components and is incident on the birefringent crystal 3d ₂ . The birefringent crystal 3d ₂ is a crystal having a different refractive index depending on the deflection component. For this reason, the light separated by the first polarizer 3d ₁ has different distances through the birefringent crystal 3d ₂ depending on the deflection component, and has different phase delays. The light that has passed through the birefringent crystal 3d ₂ passes through the second polarizer 3d ₃ so that the deflection components thereof are matched, and the light receiving element 3b of the light projecting / receiving unit 3 is irradiated as interference light according to the phase delay. Thereby, interference fringes can be generated on the light receiving element 3b. The interference fringe changes the fringe interval in accordance with the change in the distance L between the emitting portion 2 and the portion irradiated with light on the surface to be measured, and therefore the distance L is measured by analyzing the fringe interval. be able to. The light receiving element 3b supplies the interference fringes generated by the interference light to the distance measuring unit 5 as an interference signal.

The distance measuring unit 5 performs a process such as Fourier transform on the interference signal supplied by the light receiving element 3b of the light projecting / receiving unit 3 so that the light is emitted from the emitting unit 2 and the portion irradiated with light on the surface to be measured. The distance L between them is measured. The emission angle measurement unit 6 measures the emission angle θ of light emitted from the emission unit 2 based on the electrical signal supplied from the scanning unit 4. Thus, the process of measuring the distance L and the emission angle θ is performed for each of a plurality of measurement points arranged on the test surface along the direction (X direction) in which the emission angle is changed. Here, the distance L and the emission angle θ measured by emitting light from the emission unit 2 toward each measurement location are hereinafter referred to as the distance L _n and the emission angle θ _{n at} each measurement location.

The determination unit 8 is based on the distance L _n (distance information) at each measurement point measured by the distance measurement unit 5 and the emission angle θ _n (angle information) at each measurement point measured by the emission angle measurement unit 6. The position (Z direction) of each measurement location is determined. Thus, by determining the position of each measurement location arranged along the X direction based on the distance L _n and the emission angle θ _n at each measurement location, the shape (X− The cross-sectional shape of the test object along the Z plane can be measured. Further, by repeatedly performing the process of measuring the shape of the test surface 10 in the X direction while moving the measuring system 1 or the test object 9 little by little in the Y direction, the shape (XY plane) is obtained over the entire surface of the test surface 10. ) Can be measured.

In the measuring apparatus 100, an error may occur in distance information measured by irradiating light from the emitting unit 2 to the measurement location due to speckle noise or the like generated by light scattering on the test surface 10. As described above, if an error occurs due to speckle noise or the like in the distance information, it becomes difficult to measure the shape of the surface to be measured with high accuracy. Therefore, the measuring apparatus 100 irradiates a plurality of measurement points in the region including the measurement location with light from the emission unit 2, and calculates the average value (distance L _nAVE ) of the distance L measured at each measurement location at the measurement location. The distance measurement unit 5 measures the distance L _n (distance information). Thereby, errors such as speckle noise can be reduced. Similarly, the measuring apparatus 100 measures the average value (exit angle θ _nAVE ) of the exit angle θ measured at each measurement point by the exit angle measurement unit 6 as the exit angle θ _n (angle information) at the measurement location. . For example, the measuring apparatus 100 measures the distance L and the emission angle θ at a plurality of measurement points 10b _{1 to} 10b ₄ in the region 10b including the measurement location 10a. The measuring apparatus 100 are respectively measured distance mean value of L at the measurement point _10b 1 _{~10b 4} (distance _{L Nave),} is used as the distance _{L n} at the measurement point 10a. In addition, the measuring apparatus 100 uses the average value (exit angle θ _nAVE ) of the exit angles θ measured at the measurement points 10b _{1 to} 10b ₄ as the exit angle θ _n at the measurement location 10a. Here, the distance L _nAVE may be an average value when not only the distance L measured at each of the measurement points 10b _{1 to} 10b ₄ but also the distance L _n measured at the measurement location 10a. Similarly, the emission angle θ _nAVE may be an average value when not only the emission angle θ measured at each of the measurement points 10b _{1 to} 10b ₄ but also the emission angle θ _n measured at the measurement location 10a.

In recent years, it has been required to measure test surfaces of various shapes such as a test surface having a large curvature. However, when the average value (distance L _nAVE ) of the distance L measured at each measurement point is used as the distance L _n at the measurement location, even if the error due to speckle noise or the like can be reduced, the distance L _nAVE and the distance L _n An error will occur between An error also occurs between the emission angle θ _nAVE and the emission angle θ _n . If such an error occurs, it may be difficult to measure the shape of the test surface with high accuracy. Therefore, the measurement apparatus 100 according to the first embodiment uses the distance L _nAVE measured by the distance measurement unit 5 and the emission angle θ _nAVE measured by the emission angle measurement unit 6 based on the design data of the test surface 10, respectively. A calibration unit 7 for calibration is included in front of the determination unit 8. The calibration unit 7 uses the design data of the test surface 10 and assumes that the test surface 10 is formed according to the design value. In this assumption, the distance L _n ′ between the measurement location and the emission unit 2 and An average value (distance L _n ′ _AVE ) of the distance L between each measurement point and the emission unit 2 is acquired. Then, the calibration unit 7 calculates a difference between the distance L _n ′ and the distance L _n ′ _AVE in the assumed case as a first offset value, and _uses the distance L _nAVE measured by the distance measurement unit 5 as the first offset value. Calibrate with. In addition, the calibration unit 7 assumes, under the assumption, an average of the emission angle θ _n ′ when light is emitted from the emission unit 2 to the measurement location and the emission angle θ when light is emitted from the emission unit 2 to each measurement point. A value (exit angle θ _n ′ _AVE ) is acquired. Then, the calibration unit 7 calculates the difference between the emission angle θ _n ′ and the emission angle θ _n ′ _AVE in the assumed case as a second offset value, and calculates the emission angle θ _nAVE measured by the emission angle measurement unit 6. Calibrate with the second offset value. Thereby, even when the shape of the test surface 10 is greatly curved or distorted, the shape of the test surface 10 can be measured with high accuracy.

  Here, a measurement method for measuring the shape of the test surface 10 in the measurement apparatus 100 (measurement system 1) of the first embodiment will be described together with the calibration process in the calibration unit 7 with reference to FIG. FIG. 2 is a flowchart illustrating a measurement method for measuring the shape of the test surface 10.

In S101, the measurement system 1 uses the average value (exit angle θ _nAVE ) of the exit angle θ measured at a plurality of measurement points in the region including the measurement place as the exit angle θ _n (angle information) at the measurement place. Measurement is performed by the emission angle measurement unit 6. In addition, the measurement system 1 uses the average value (distance L _nAVE ) of the distance L measured at a plurality of measurement points in the region including the measurement location as the distance L _n (distance information) at the measurement location. Measure by Such measurement is performed at a plurality of measurement points on the surface to be measured. The emission angle θ _nAVE and the distance L _{nAVE at} each measured measurement point are shown, for example, as shown in FIG. FIG. 3 is a diagram showing an emission angle θ (FIG. 3A) and a distance L (FIG. 3B) with respect to a position in the X direction on the test surface. In FIG. 3, a point 31 on the horizontal axis (X axis) indicates each measurement point, and a point 32 in FIG. 3A indicates the emission angle θ _nAVE measured as the emission angle θ _{n at} each measurement point. A point 33 in 3 (b) indicates the distance L _nAVE measured as the distance L _{n at} each measurement location. Here, the plurality of measurement locations are arbitrarily set positions on the test surface, and are set to be arranged on the test surface at regular intervals along the X direction, for example. In addition, the region including the measurement location is set so that the measurement location is the center, and the plurality of measurement points are set to be arranged along the X direction, for example.

In S102, the measurement system 1 assumes that the test surface 10 is formed as designed, and in this assumption, the output angle θ indicating the relationship of the output angle θ ′ to the position in the X direction on the test surface. '(Second profile) is generated by the calibration unit 7. Further, the measurement system 1 assumes that the test surface 10 is formed as designed, and in this assumption, the profile of the distance L ′ indicating the relationship of the distance L ′ to the position in the X direction on the test surface. The (first profile) is generated by the calibration unit 7. That is, the profile of the emission angle θ ′ and the profile of the distance L ′ are generated using the design data (CAD data) of the test surface 10. For example, the calibration unit 7 irradiates light from the emitting unit 2 to each measurement point (each measurement point in the design data) on the test surface when it is assumed that the test surface 10 is formed as designed. The emission angle θ ′ of the light at that time is acquired using the formula (1). Thereby, a profile of the emission angle θ ′ can be generated. Further, the calibration unit 7 can generate a profile of the distance L ′ by acquiring the distance L ′ between each measurement point in the design data and the emitting unit 2 using the formula (2). Here, _{x w} and _{y w} are the coordinates of the measurement points in the design _data, x _{p, y} p and _{z p} are the coordinates of the exit portion 2. F is a function for calculating the emission angle θ ′ from the coordinates of each measurement point in the design data and the coordinates of the emission unit 2, and G _design is the coordinate and emission angle θ of each measurement point in the design data. This is a function for calculating the distance L ′ by “and”.

  The profile of the emission angle θ ′ and the profile of the distance L ′ generated using the design data of the test surface 10 in this way are shown in FIG. 4, for example. FIG. 4 is a diagram showing a profile of the emission angle θ ′ (FIG. 4A) and a profile of the distance L ′ (FIG. 4B) with respect to the position in the X direction on the test surface. In FIG. 4, a point 41 on the horizontal axis (X axis) indicates each measurement point in the design data, a point 42 in FIG. 4A indicates the emission angle θ ′ acquired at each measurement point in the design data, A point 43 in FIG. 4B indicates the distance L ′ acquired at each measurement point in the design data.

In S103, the measurement system 1 emits light from the emission unit 2 to each measurement location (each measurement location in the design data) on the test surface when it is assumed that the test surface 10 is formed as designed. The light emission angle θ _n ′ when irradiated is acquired by the calibration unit 7 using Equation (3). In addition, the measurement system 1 acquires the distance L _n ′ between each measurement location in the design data and the emission unit 2 by the calibration unit 7 using Expression (4). Here, x _wn and y _wn are the coordinates of each measurement location in the design data.

Thus, the emission angle θ _n ′ and the distance L _n ′ acquired using the design data of the test surface 10 are shown, for example, as shown in FIG. FIG. 5 is a diagram showing the emission angle θ _n ′ (FIG. 5A) and the distance L _n ′ (FIG. 5B) with respect to the position in the scanning direction (X direction). In FIG. 5, a point 51 on the horizontal axis (X axis) indicates each measurement location in the design data, and corresponds to the point 31 in FIG. Further, a point 52 in FIG. 5A indicates the emission angle θ _n ′ acquired at each measurement location in the design data, and a point 53 in FIG. 5B indicates a distance acquired at each measurement location in the design data. L _n 'is shown. Here, in the first embodiment, the emission angle θ _n ′ and the distance L _n ′ are acquired using Expression (3) and Expression (4), respectively, but the present invention is not limited to this, and the emission angle θ ′ You may acquire each based on the profile and the profile of distance L '. For example, it is assumed that the point 41b among the plurality of points 41 (measurement points in the design data) in FIG. 4 matches the point 51a (measurement location in the design data) in FIG. In this case, for the emission angle θ _n ′ (point 52a) at the point 51a, it is only necessary to extract the emission angle θ ′ (point 42b) at the point 41b from the profile of the emission angle θ ′ shown in FIG. Similarly, for the distance L _n ′ (point 53a) at the point 51a, it is only necessary to extract the distance L ′ (point 43b) at the point 41b from the profile of the distance L ′ shown in FIG. Further, when the profile of the emission angle θ ′ and the profile of the distance L ′ shown in FIG. 4 are represented by equations, the emission angle θ _n ′ and the distance L _n ′ may be obtained by the equations. In this case, the output angle θ _n ′ and the distance L _n ′ can be obtained using only the position in the X direction in the design data as a parameter.

In S104, the measurement system 1 calibrates the average value (exit angle θ _n ′ _AVE ) of the output angle θ ′ in the region including each measurement location in the design data based on the profile of the output angle θ ′ generated in S102. Obtained by part 7. In addition, the measurement system 1 uses the calibration unit 7 to obtain an average value of the distance L ′ (distance L _n ′ _AVE ) in the region including each measurement location in the design data based on the profile of the distance L ′ generated in S102. To do. A process of obtaining the emission angle θ _n ′ _AVE and the distance L _n ′ _AVE will be described with reference to FIG. FIG. 6 is a diagram in which the emission angle θ _n ′ _AVE and the distance L _n ′ _AVE are shown together with FIG. 4 and FIG. 6A is a diagram showing the emission angle θ ′ with respect to the position in the X direction on the test surface, and FIG. 6B is a diagram showing the distance L ′ with respect to the position in the X direction on the test surface. is there. For example, the region 61a including the measurement location (point 51a) in the design data is set, and the average value of the emission angles θ ′ (points 42a to 42d) in the region 61a is obtained, whereby the emission angle at the measurement location indicated by the point 51a. θ _n ′ _AVE (point 62a) can be acquired. Further, by obtaining the average value of the distance L ′ (points 43a to 43d) in the region 61a, the distance L _n ′ _AVE (point 63a) at the measurement location indicated by the point 51a can be acquired. Similarly, by obtaining the average value of the emission angle θ ′ in the region 61b, the emission angle θ _n ′ _AVE (point 62b) and the distance L _n ′ _AVE (point 63b) at the measurement location indicated by the point 51b are obtained. Can do. By obtaining the average value of the emission angle θ ′ in the region 61c, the emission angle θ _n ′ _AVE (point 62c) and the distance L _n ′ _AVE (point 63c) at the measurement location indicated by the point 51c can be obtained. The emission angle θ _n ′ _AVE and the distance L _n ′ _AVE acquired in this way are expressed by Expression (5) and Expression (6), respectively. C _n is the number of measurement points included in the region including the measurement location, and D _n is the length in the X direction of the region including the measurement location. Here, the area that is set when obtaining the emission angle theta _{n 'AVE} and the distance _{L n' AVE} in S104 (region including the measurement point), at the time of measuring the emission angle theta _AVE and the distance the distance _{L AVE} in S101 It is good to set so as to correspond to the area set to.

In S105, the measurement system 1, the correction unit 7, the offset value [Delta] [theta] _n (second offset value) of the emission angle difference between 'acquired emission angle theta _n in the S104' _AVE emission angle theta _n acquired in S103 Calculate as In the measurement system 1, the calibration unit 7 calculates the difference between the distance L _n ′ extracted in S103 and the emission angle L _n ′ _AVE acquired in S104 as a distance offset value ΔL _n (first offset value). . The emission angle offset value Δθ _n and the distance offset value ΔL _n calculated in this way are expressed by Expression (7) and Expression (8), respectively.

In S106, the measurement system 1 uses the emission angle θ _nAVE and the distance L _nAVE measured in S101 in the calibration unit 7 by using the emission angle offset value Δθ _n and the distance offset value ΔL _n calculated in S105. Calibrate each one. In S107, the measurement system 1 uses the determining unit 8 to determine each measurement location based on the output angle θ _nAVE and the distance L _nAVE of each measurement location calibrated by the output angle offset value Δθ _n and the distance offset value ΔL _n . Determine the position. The position [X _n , Y _n , Z _n ] of each measurement location determined in S107 is expressed by Expression (9). Thus, by determining the position of each measurement location, the shape of the test surface 10 (the cross-sectional shape of the test object along the XZ plane) can be measured. Here, f is a function for determining the shape of the test surface based on the emission angle θ and the distance L at each measurement location.

As described above, the measuring apparatus 100 according to the first embodiment uses the distance L _nAVE and the emission angle θ _nAVE as the distance L _n (distance information) and the emission angle θ _n (angle information) at each measurement location. The shape of the surface is measured. The distance L _nAVE and the emission angle θ _nAVE are calibrated by the distance offset value ΔL _n and the emission angle offset value Δθ _n obtained from the design data of the surface to be measured. Accordingly, various shapes of test surfaces such as a test surface having a large curvature can be measured with high accuracy. Here, in the measuring apparatus 100 of the first embodiment, the distance L _nAVE and the emission angle θ _nAVE are calibrated by the respective offset values, but the present invention is not limited to this, and the distance is obtained without calibrating the emission angle θ _nAVE. L _n only may be calibrated to. For example, when changing the emission angle of the light emitted from the emission unit 2 at a constant angular velocity by the scanning unit 4 and setting each measurement location in a certain time, that is, each measurement location each time the emission angle advances a certain angle Suppose that is set. In this case, since the exit angle θ _{n at} each measurement location is inevitably determined by the angular velocity and time in the scanning unit, the average value (exit angle θ _nAVE ) of the exit angle θ in the region including the measurement location is _taken as the exit angle θ _n. There is no need to measure. Therefore, in this case, if only the distance L _nAVE is calibrated, the shape of the test surface can be measured with high accuracy.

<Embodiment of Method for Manufacturing Article>
The method for manufacturing an article in the embodiment of the present invention is used, for example, when processing an article such as an optical element such as a lens or a mirror. The method for manufacturing an article according to the present embodiment includes a step of measuring the shape of the test object using the above-described measuring device, and a process of processing the test object based on the measurement result in the process. For example, the shape of the test object is measured using a measuring device, and the test object is processed based on the measurement result so that the shape of the test object becomes a design value. The method for manufacturing an article according to the present embodiment is advantageous in at least the processing accuracy of the article as compared to the conventional method because the shape of the test object can be measured with high accuracy by the measuring device.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Claims (10)

Angle information indicating the light emission angle when light is emitted from the emission part that emits light toward the test surface to the measurement location on the test surface, and the distance between the measurement location and the emission unit A measurement method for measuring the position of the measurement location based on the distance information shown,
A measurement step of measuring an average value of the distance between each of a plurality of measurement points in the region including the measurement location and the emission part;
Using the design data of the test surface, assuming that the test surface is formed according to the design value, in the assumption, the distance between the measurement location and the emitting portion, the plurality of measurement points, A calculation step of calculating a difference between the average value of the distance to the emitting part and the first offset value;
A calibration step of calibrating the average value of the distances measured in the measurement step with the first offset value;
A determination step using the value calibrated with the first offset value as the distance information, and determining the position of the measurement location;
A measuring method characterized by comprising. In the measurement step, the average value of the light emission angle when the light is emitted from the emission part to each measurement point is measured,
In the calculation step, using the design data, it is assumed that the test surface is formed according to a design value, and in this assumption, an emission angle when light is emitted from the emission unit to the measurement location and The difference from the average value of the emission angle when light is emitted from the emission part to the plurality of measurement points is calculated as a second offset value,
In the calibration step, the average value of the emission angles measured in the measurement step is calibrated with the second offset value,
The measurement method according to claim 1, wherein in the determination step, a position calibrated with the second offset value is further used as the angle information to determine the position of the measurement location. Using the design data, it is assumed that the test surface is formed according to a design value, and in this assumption, the relationship between the position on the test surface and the distance between the position and the emitting portion is expressed. Further comprising a generating step of generating a first profile;
In the calculation step, the distance between the measurement location and the emission part and the average value of the distances between the plurality of measurement points and the emission part are respectively acquired based on the first profile. The measurement method according to claim 1. Using the design data, it is assumed that the test surface is formed according to a design value, and in this assumption, the relationship between the position on the test surface and the distance between the position and the emitting portion is expressed. And further including a generation step of generating a first profile and a second profile representing a relationship between the light emission angles at the light emitting portion,
In the calculation step,
The distance between the measurement location and the emission part, and the average value of the distance between the plurality of measurement points and the emission part, respectively, based on the first profile,
Based on the second profile, an emission angle when light is emitted from the emission unit to the measurement location and an average value of emission angles when light is emitted from the emission unit to the plurality of measurement points are obtained based on the second profile, respectively. The measuring method according to claim 2, wherein: The plurality of measurement points are arranged along a direction in which an emission angle of light is changed by the emission unit,
The measurement method according to claim 1, wherein the region including the measurement location is a region centering on the measurement location.   6. The measurement according to claim 1, wherein the test surface includes a plurality of the measurement locations arranged along a direction in which a light emission angle is changed by the emission unit. Method.   The measurement method according to claim 1, wherein in the measurement step, a distance between each measurement point and the emission unit is measured using light interference. The emission part includes a galvanometer mirror, an acoustooptic device, a polygon mirror or a MEMS,
The measurement method according to claim 1, wherein the emission angle is changed by driving the galvanometer mirror, an acoustooptic device, a polygon mirror, or a MEMS. Angle information indicating the light emission angle when light is emitted from the emission part that emits light toward the test surface to the measurement location on the test surface, and the distance between the measurement location and the emission unit A measuring device for measuring the position of the measurement location based on the distance information shown,
A measurement unit that measures an average value of the distance between each of a plurality of measurement points in the region including the measurement point and the emission unit;
Using the design data of the test surface, assuming that the test surface is formed according to the design value, in the assumption, the distance between the measurement location and the emitting portion, the plurality of measurement points, A calibration unit that calculates a difference between the average value of the distance to the emitting unit as a first offset value and calibrates the average value of the distance measured by the measurement unit with the first offset value;
Using a value calibrated with the first offset value as the distance information, and a determination unit for determining the position of the measurement location;
A measuring device comprising: Measuring the shape of the test surface using the measuring device according to claim 9;
Processing the test surface based on the measurement result in the step;
A method for producing an article comprising:

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