WO2013084565A1 - Data correction apparatus and data correction program - Google Patents

Data correction apparatus and data correction program Download PDF

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Publication number
WO2013084565A1
WO2013084565A1 PCT/JP2012/074504 JP2012074504W WO2013084565A1 WO 2013084565 A1 WO2013084565 A1 WO 2013084565A1 JP 2012074504 W JP2012074504 W JP 2012074504W WO 2013084565 A1 WO2013084565 A1 WO 2013084565A1
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data
information
correction value
correction
height data
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PCT/JP2012/074504
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French (fr)
Japanese (ja)
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軌行 石井
俊哉 瀧谷
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コニカミノルタ株式会社
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Publication of WO2013084565A1 publication Critical patent/WO2013084565A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/0209—Low-coherence interferometers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G01B11/2441—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures using interferometry

Definitions

  • the present invention relates to a data correction apparatus and a data correction program.
  • a shape measuring device using white light interference generates white light interference fringes by condensing white light emitted from a white light source on a work surface by a microscope objective lens, and images the white light interference fringes with an area sensor. Thus, the height data of the pixels included in the imaging area of the area sensor is calculated.
  • the microscope objective lens of the shape measuring apparatus is designed to minimize aberration when the workpiece surface is perpendicular to the optical axis. For this reason, when the measurement object area
  • Patent Document 1 discloses a shape measuring device having a rotation mechanism capable of rotating a microscope objective lens. According to such a configuration, since the microscope objective lens is rotated so that the optical axis is perpendicular to the inclined surface of the workpiece, errors due to the aberration of the microscope objective lens are suppressed, and the workpiece shape is accurately measured. be able to.
  • the present invention has been made in order to solve the above-described problems, and is a data correction apparatus capable of accurately measuring the workpiece shape without changing the relative inclination between the workpiece and the microscope objective lens. And it aims at providing a data correction program.
  • a storage unit that stores information that associates an inclination angle of a small area on a workpiece measured by an optical shape measuring apparatus with a correction value for correcting height data of the small area;
  • An acquisition unit that acquires height data of a predetermined area obtained by measuring a workpiece by the shape measuring device; a calculation unit that calculates an inclination angle of the predetermined area from which height data is acquired by the acquisition unit;
  • a determination unit that determines a correction value corresponding to the tilt angle calculated by the calculation unit, and the correction value determined by the determination unit, And a correction unit that corrects the height data acquired by the acquisition unit.
  • the shape measuring apparatus includes an area sensor, the predetermined area is a partial area of the imaging area of the area sensor, and the correction value is a position of the predetermined area in the imaging area. Further, the information is information that associates the inclination angle, the position, and the correction value, and the determination unit determines the correction value corresponding to the inclination angle and the position using the information.
  • the data correction apparatus according to any one of (1) to (5) above.
  • Correction program for causing a computer to execute the step (d) of correcting the height data.
  • the shape measuring device includes an area sensor, the predetermined area is a partial area of the imaging area of the area sensor, and the correction value is a position of the predetermined area in the imaging area. Further, the information is information in which the inclination angle, the position, and the correction value are associated with each other, and the correction value corresponding to the inclination angle and the position using the information in the step (c).
  • the data correction program according to any one of (7) to (11) above, in which is determined.
  • the relative inclination between the work and the microscope objective lens is changed. Therefore, the workpiece shape can be measured with high accuracy.
  • FIG. 1 It is a figure showing a schematic structure of a shape measuring system concerning a 1st embodiment of the present invention. It is a block diagram which shows schematic structure of the information processing apparatus shown by FIG. It is a flowchart which shows the procedure of the height data correction process performed by information processing apparatus. It is a figure which shows the relationship between the inclination angle of a workpiece
  • FIG. 1 is a diagram showing a schematic configuration of a shape measuring system 1 according to the first embodiment of the present invention.
  • the shape measurement system 1 includes a shape measurement device 10 and an information processing device 20.
  • the shape measuring apparatus 10 measures the workpiece surface using white light interference.
  • the shape measuring apparatus 10 is configured by attaching a microscope objective lens 12 to a microscope main body 11.
  • the microscope objective lens 12 condenses the white light supplied from the microscope main body 11 on the work surface to generate white light interference fringes. Further, the microscope objective lens 12 is moved in the optical axis direction by a piezoelectric element.
  • An area sensor 13 is provided on the upper part of the microscope main body 11, and images white light interference fringes generated by irradiating the work surface with white light. A plurality of image data obtained by imaging the white light interference fringes by the area sensor 13 while moving the microscope objective lens 12 by the piezo element is transmitted to the information processing apparatus 20.
  • the information processing device 20 controls the operation of the shape measuring device 10 and analyzes the image data received from the shape measuring device 10 to calculate the height data of the pixels included in the imaging region of the area sensor 13. Moreover, the information processing apparatus 20 corrects the height data of the pixels included in the imaging region using information in which a tilt angle described later and a correction value for correcting the error are associated as a data correction apparatus.
  • FIG. 2 is a block diagram illustrating a schematic configuration of the information processing apparatus 20.
  • the information processing apparatus 20 includes a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, a hard disk 24, an input unit 25, a display unit 26, and a transmission / reception unit 27. These units are connected to each other via a bus 28.
  • CPU Central Processing Unit
  • ROM Read Only Memory
  • RAM Random Access Memory
  • the CPU 21 executes various calculations and processes on the image data received from the shape measuring apparatus 10.
  • the CPU 21 functions as an analysis unit, an acquisition unit, a calculation unit, a determination unit, and a correction unit.
  • the analysis unit analyzes the image data received from the shape measuring apparatus 10 and calculates pixel height data.
  • the acquisition unit acquires the height data of each pixel calculated by the analysis unit.
  • the calculation unit calculates the tilt angle of the pixel based on the pixel height data acquired by the acquisition unit.
  • the determination unit determines a correction value corresponding to the tilt angle calculated by the calculation unit using information stored in the hard disk 24.
  • the correction unit corrects the pixel height data using the correction value determined by the determination unit. The specific processing contents of each unit will be described later.
  • the ROM 22 stores various programs and various data in advance.
  • the RAM 23 temporarily stores programs and data as a work area.
  • the hard disk 24 stores various programs including the operating system and various data.
  • the hard disk 24 stores a function for calculating a correction value from the tilt angle.
  • the hard disk 24 analyzes an image data received from the shape measuring apparatus 10 to calculate pixel height data, an acquisition program for acquiring pixel height data, and a pixel tilt angle.
  • a calculation program for calculation, a determination program for determining a correction value corresponding to the tilt angle, and a correction program for correcting pixel height data are stored.
  • the input unit 25 is a pointing device such as a keyboard, a touch panel, and a mouse, and is used for inputting various information.
  • the display part 26 is a liquid crystal display, for example, and displays various information.
  • the transmission / reception unit 27 is an interface, for example, and receives image data from the shape measuring apparatus 10. Further, the transmission / reception unit 27 outputs various commands for controlling the operation of the shape measuring apparatus 10.
  • shape measuring device 10 and the information processing device 20 may include components other than the above-described components, or some of the above-described components may not be included.
  • the image data received from the shape measuring device 10 is analyzed by the information processing device 20, and the height data of each pixel of the image data is calculated. Then, the height data of each pixel is corrected according to the tilt angle.
  • the operation of the information processing apparatus 20 according to the present embodiment will be described with reference to FIG. 3 and FIG. 4.
  • FIG. 3 is a flowchart showing a procedure of height data correction processing executed by the information processing apparatus 20. Note that the algorithm shown in the flowchart of FIG. 3 is stored as a program in the hard disk 24 of the information processing apparatus 20 and is executed by the CPU 21.
  • the image data received from the shape measuring apparatus 10 is analyzed, and the height data of each pixel is calculated. Specifically, the plurality of pieces of image data received from the shape measuring apparatus 10 are analyzed, and the peak intensity position of the white light interference fringe is obtained, whereby the height data of each pixel is calculated. For example, when the imaging area of the area sensor is 256 ⁇ 256 pixels, height data is calculated for all pixels. Note that a technique for analyzing the image data and calculating the height data for each pixel is a known technique, and thus detailed description thereof is omitted.
  • one pixel is selected from the plurality of pixels whose height data has been calculated in S01. Then, a pixel group of a small region including the one pixel and the peripheral pixels of the one pixel is selected, and height data of the pixel group is acquired. For example, one pixel is selected from 256 ⁇ 256 pixels. Then, a pixel group of a small region including the one pixel and four pixels above, below, left, and right of the one pixel is selected, and height data of the pixel group is acquired.
  • the inclination angle of one pixel selected in S02 is calculated from the height data of the pixel group from which the height data was acquired in S02. Specifically, for example, the tilt angle in the X direction and the tilt angle in the Y direction of the pixel are calculated using the height data of the pixel group. Note that the X direction and the Y direction indicate the moving direction of the stage perpendicular to the optical axis (Z axis) of the shape measuring apparatus 10.
  • a correction value corresponding to the tilt angle calculated in S03 is determined using the function stored in the hard disk 24.
  • the function for determining the correction value f (x t , y t ) is, for example, an n-order polynomial function, where x t is the tilt angle in the X direction and y t is the tilt angle in the Y direction. It is expressed as (1).
  • a ij is an inclination correction coefficient array.
  • the function of equation (1) is stored in the hard disk 24.
  • the inclination angle of the X direction x t of the following formula (1), by substituting each inclination angle of the Y-direction in y t, the correction value f is determined.
  • the pixel height data acquired in S02 is corrected using the correction value f determined in S04. Specifically, the correction value is added or subtracted from the height data.
  • S06 it is determined whether or not the correction of the height data of all the pixels has been completed. Specifically, for example, it is determined whether or not the height data of 256 ⁇ 256 pixels included in the area sensor 13 has been corrected.
  • the height data of the pixels included in the imaging region of the area sensor 13 is corrected based on the tilt angle.
  • FIG. 4 is a diagram showing the relationship between the tilt angle of the workpiece W and the reflected light.
  • the height data of each pixel is corrected according to the inclination angle of the workpiece W corresponding to each pixel, even if the measurement target region of the workpiece W is an inclined surface, The workpiece shape can be measured with high accuracy.
  • the workpiece shape can be measured with high accuracy without changing the relative inclination between the workpiece W and the microscope objective lens 12.
  • FIG. 5 is a flowchart showing the procedure of the function creation process executed by the information processing apparatus 20. Note that the algorithm shown in the flowchart of FIG. 5 is stored as a program in the hard disk 24 of the information processing apparatus 20 and is executed by the CPU 21.
  • a spherical original device having a known shape Prior to the creation of the function, a spherical original device having a known shape is prepared, and a plurality of areas of the spherical original device are measured by the shape measuring apparatus 10.
  • a plurality of image data obtained by measuring the spherical original device by the shape measuring apparatus 10 are analyzed, and height data of a plurality of regions of the spherical original device are calculated.
  • a difference between the height data and the actual height data of the spherical original device is calculated, and a correction value of the height data is calculated for each pixel.
  • the actual height data is geometrically calculated from the radius of the spherical prototype and the measurement position.
  • the inclination angle of the region corresponding to the pixel is geometrically calculated from the radius of the spherical prototype and the measurement position. Specifically, the inclination angle is calculated by calculating the normal vector V of the tangential plane P of the spherical original device B (see FIG. 6). Unlike the present embodiment, the tilt angle may be calculated using the height data of the surrounding pixels, as in S03 of FIG. In this case, a high frequency removal filter or differentiation processing may be used.
  • the correction value is defined as a function of the tilt angle based on the correction value and the tilt angle calculated in S12 and S13.
  • n-th order polynomial approximation is performed, and the coefficient array aij shown in the above equation (1) is calculated. Note that although an n-th order polynomial is described in the expression (1), a Zernike polynomial may be used as a function.
  • a function for calculating a correction value from an inclination angle is created by measuring a spherical prototype.
  • the correction value corresponding to the inclination angle of each pixel is determined using a function for calculating the correction value from the inclination angle.
  • a correction value corresponding to the tilt angle of each pixel may be determined using a lookup table.
  • FIG. 7 is a diagram illustrating an example of the lookup table 100.
  • the look-up table 100 is information that associates inclination angles of pixels in the X direction and Y direction with correction values. For example, when the tilt angle calculated in S03 of FIG. 3 is 31 ° with respect to the X direction and 30 ° with respect to the Y direction, the correction value is determined to be 6 nm from the lookup table 100. When the corresponding inclination angle does not exist in the lookup table 100, the correction value can be determined by interpolation.
  • the interpolation is, for example, linear interpolation for calculating a numerical value between the numerical value N1 and the numerical value N2, assuming that the numerical value N1 and the numerical value N2 are linear.
  • the position of the pixel in the imaging region of the area sensor 13 is further associated with a correction value for correcting the height data of each pixel.
  • FIG. 8 is a flowchart showing a procedure of height data correction processing according to the present embodiment. Since S21 to S23 are the same as S01 to S03 in FIG.
  • a correction value corresponding to the tilt angle and pixel position calculated in S23 is determined using a function that associates the tilt angle, the pixel position, and the correction value stored in the hard disk 24.
  • the function for determining the correction value g (x t , y t , x p , y p ) is such that the tilt angle of the pixel in the X direction is x t , the tilt angle in the Y direction is y t , and the X coordinate of the pixel is x p , when the Y coordinate of the pixel was set to y p, for example, by using the n-order polynomial function can be expressed as the following equation (2).
  • b ijkl is a coefficient array of polynomials for inclination and position correction.
  • the function of equation (2) is stored in the hard disk 24.
  • the inclination angle of the following (2) X direction x t of formula, the inclination angle of the Y-direction in y t, the X coordinate of the pixel in x p, by substituting the Y coordinate of the pixel, respectively y p, correction
  • the value g is determined.
  • the following equation (2) is calculated by measuring a spherical original device, similarly to equation (1).
  • S25 and S26 are the same as S05 and S06 in FIG.
  • the error caused by the position of the pixel in the measurement region of the area sensor 13 can be corrected. it can.
  • the error due to the position of the pixel becomes more prominent as the tilt angle becomes larger.
  • the correction value of the pixel located at the center of the area sensor 13 and the pixel located at the corner of the area sensor 13 The correction value may be different. According to this embodiment, even when the tilt angle of the workpiece W is large, the workpiece shape can be accurately measured.
  • the tilt angle, the pixel position, and the correction value may be associated with each other by a lookup table.
  • the height data of the pixels included in the imaging region of the area sensor 13 is corrected for each pixel.
  • the imaging area of the area sensor 13 for example, 256 ⁇ 256 pixels
  • the data may be corrected.
  • the inclination angle of the workpiece W in each pixel is calculated based on the pixel height data.
  • the inclination angle of the predetermined area of the workpiece W may be calculated using CAD data of the workpiece.
  • the design formula may be used.
  • a spherical original device is used.
  • a prototype having an uneven surface with a known shape or an inclined surface with a known tilt angle may be used as the prototype.
  • the height data is corrected by the CPU 21 executing the program stored in the hard disk 24.
  • the process of correcting the height data may be executed by a hardware circuit such as an FPGA (Field Programmable Gate Array).
  • the height data of a plurality of pixels is corrected simultaneously by parallel processing.
  • the means and method for performing various processes in the shape measurement system 1 according to the first and second embodiments described above can be realized by either a dedicated hardware circuit or a programmed computer.
  • the program may be provided by a computer-readable recording medium such as a flexible disk and a CD-ROM, or may be provided online via a network such as the Internet.
  • the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk.
  • the program may be provided as a single application software, or may be incorporated in the software of the apparatus as one function of the shape measurement system 1.

Abstract

[Problem] To provide a data correction apparatus and a data correction program, which make it possible to highly accurately measure shapes of workpieces without changing relative tilts of the workpieces and a microscope objective lens. [Solution] This data correction apparatus has: a storage unit, which stores information, in which a tilt angle of a region measured by means of a shape measuring apparatus (10) using white light interference, and a correction value for correcting height data of the region are associated with each other; an acquiring unit, which acquires height data of a predetermined region, said height data having been obtained by measuring a workpiece (W) by means of the shape measuring apparatus (10); a calculating unit, which calculates a tilt angle of the predetermined region, the height data of which has been acquired by the acquiring unit; a determining unit, which determines, using the information stored in the storage unit, a correction value that corresponds to the tilt angle calculated by means of the calculating unit; and a correcting unit, which corrects the height data using the correction value determined by means of the determining unit, said height data having been acquired by means of the acquiring unit.

Description

データ補正装置及びデータ補正プログラムData correction apparatus and data correction program
　本発明は、データ補正装置及びデータ補正プログラムに関する。 The present invention relates to a data correction apparatus and a data correction program.
　デジタルカメラやレーザービームプリンターの高性能化に伴い、これらに内蔵された光学素子の形状を高精度に測定することが求められている。光学素子を高精度に測定する形状測定装置として、白色光干渉を用いた形状測定装置が知られている。白色光干渉を用いた形状測定装置は、白色光光源から出射される白色光を顕微鏡対物レンズによりワーク表面に集光させて白色光干渉縞を発生させ、白色光干渉縞をエリアセンサにより撮像して、エリアセンサの撮像領域に含まれる画素の高さデータを算出する。 As digital cameras and laser beam printers become more sophisticated, it is required to measure the shape of the optical elements built into them with high accuracy. As a shape measuring device for measuring an optical element with high accuracy, a shape measuring device using white light interference is known. A shape measuring device using white light interference generates white light interference fringes by condensing white light emitted from a white light source on a work surface by a microscope objective lens, and images the white light interference fringes with an area sensor. Thus, the height data of the pixels included in the imaging area of the area sensor is calculated.
　ところで、形状測定装置の顕微鏡対物レンズは、ワーク表面が光軸に対して垂直のとき、収差が最小となるよう設計されている。このため、ワークの測定対象領域が傾斜面である場合、顕微鏡対物レンズの収差の影響が大きくなり、測定精度の低下が招かれている。 By the way, the microscope objective lens of the shape measuring apparatus is designed to minimize aberration when the workpiece surface is perpendicular to the optical axis. For this reason, when the measurement object area | region of a workpiece | work is an inclined surface, the influence of the aberration of a microscope objective lens becomes large, and the fall of a measurement precision is caused.
　この問題を解決するために、下記の特許文献１には、顕微鏡対物レンズを回転可能な回転機構を有する形状測定装置が開示されている。このような構成によれば、ワークの傾斜面に対して光軸が垂直となるように顕微鏡対物レンズが回転されるため、顕微鏡対物レンズの収差による誤差が抑制され、ワーク形状を精度良く測定することができる。 In order to solve this problem, the following Patent Document 1 discloses a shape measuring device having a rotation mechanism capable of rotating a microscope objective lens. According to such a configuration, since the microscope objective lens is rotated so that the optical axis is perpendicular to the inclined surface of the workpiece, errors due to the aberration of the microscope objective lens are suppressed, and the workpiece shape is accurately measured. be able to.
　しかしながら、特許文献１に記載の形状測定装置は回転機構を有するため、装置が大型化するという問題や、回転機構の回転誤差に起因する測定誤差が発生するという問題がある。 However, since the shape measuring apparatus described in Patent Document 1 has a rotation mechanism, there are problems that the apparatus is increased in size and a measurement error due to a rotation error of the rotation mechanism occurs.
特開２００１－１６５６２９号公報JP 2001-165629 A
　本発明は、上記の課題を解決するためになされたものであり、ワークと顕微鏡対物レンズとの相対的な傾きを変化させることなく、ワーク形状を精度良く測定することを可能にするデータ補正装置及びデータ補正プログラムを提供することを目的とする。 The present invention has been made in order to solve the above-described problems, and is a data correction apparatus capable of accurately measuring the workpiece shape without changing the relative inclination between the workpiece and the microscope objective lens. And it aims at providing a data correction program.
　本発明の上記目的は、下記の手段により達成される。 The above object of the present invention is achieved by the following means.
　（１）光学式の形状測定装置により測定されるワーク上の小領域の傾斜角度と当該小領域の高さデータを補正するための補正値とを関連付けた情報を記憶している記憶部と、前記形状測定装置によりワークを測定して得られる所定領域の高さデータを取得する取得部と、前記取得部により高さデータが取得された前記所定領域の傾斜角度を算出する算出部と、前記記憶部に記憶されている前記情報を用いて、前記算出部により算出された前記傾斜角度に対応する補正値を決定する決定部と、前記決定部により決定された前記補正値を用いて、前記取得部により取得された高さデータを補正する補正部と、を有するデータ補正装置。 (1) a storage unit that stores information that associates an inclination angle of a small area on a workpiece measured by an optical shape measuring apparatus with a correction value for correcting height data of the small area; An acquisition unit that acquires height data of a predetermined area obtained by measuring a workpiece by the shape measuring device; a calculation unit that calculates an inclination angle of the predetermined area from which height data is acquired by the acquisition unit; Using the information stored in the storage unit, a determination unit that determines a correction value corresponding to the tilt angle calculated by the calculation unit, and the correction value determined by the determination unit, And a correction unit that corrects the height data acquired by the acquisition unit.
　（２）前記情報は、関数である上記（１）に記載のデータ補正装置。 (2) The data correction apparatus according to (1), wherein the information is a function.
　（３）前記情報は、ルックアップテーブルである上記（１）に記載のデータ補正装置。 (3) The data correction apparatus according to (1), wherein the information is a lookup table.
　（４）前記情報は、形状が既知である原器を測定して得られる上記（１）～（３）のいずれか１つに記載のデータ補正装置。 (4) The data correction apparatus according to any one of (1) to (3), wherein the information is obtained by measuring a prototype having a known shape.
　（５）前記原器は、球面原器である上記（４）に記載のデータ補正装置。 (5) The data correction apparatus according to (4), wherein the original device is a spherical original device.
　（６）前記形状測定装置にはエリアセンサが備えられ、前記所定領域は、前記エリアセンサの撮像領域の一部の領域であり、前記補正値は、前記撮像領域内における前記所定領域の位置とさらに関連付けられ、前記情報は、前記傾斜角度と前記位置と前記補正値とを関連付けた情報であり、前記決定部は、前記情報を用いて、前記傾斜角度及び前記位置に対応する補正値を決定する上記（１）～（５）のいずれか１つに記載のデータ補正装置。 (6) The shape measuring apparatus includes an area sensor, the predetermined area is a partial area of the imaging area of the area sensor, and the correction value is a position of the predetermined area in the imaging area. Further, the information is information that associates the inclination angle, the position, and the correction value, and the determination unit determines the correction value corresponding to the inclination angle and the position using the information. The data correction apparatus according to any one of (1) to (5) above.
　（７）光学式の形状測定装置によりワークを測定して得られる所定領域の高さデータを取得する手順（ａ）と、前記手順（ａ）において高さデータが取得された前記所定領域の傾斜角度を算出する手順（ｂ）と、前記形状測定装置により測定されるワーク上の小領域の傾斜角度と当該小領域の高さデータを補正するための補正値とを関連付けた情報を用いて、前記手順（ｂ）において算出された前記傾斜角度に対応する補正値を決定する手順（ｃ）と、前記手順（ｃ）において決定された前記補正値を用いて、前記手順（ａ）において取得された高さデータを補正する手順（ｄ）と、をコンピューターに実行させるデータ補正プログラム。 (7) Procedure (a) for acquiring height data of a predetermined area obtained by measuring a workpiece with an optical shape measuring device, and inclination of the predetermined area for which height data was acquired in the procedure (a) Using information relating the procedure (b) for calculating the angle, the inclination angle of the small area on the workpiece measured by the shape measuring apparatus, and the correction value for correcting the height data of the small area, Using the procedure (c) for determining the correction value corresponding to the tilt angle calculated in the procedure (b) and the correction value determined in the procedure (c), the correction value is acquired in the procedure (a). Correction program for causing a computer to execute the step (d) of correcting the height data.
　（８）前記情報は、関数である上記（７）に記載のデータ補正プログラム。 (8) The data correction program according to (7), wherein the information is a function.
　（９）前記情報は、ルックアップテーブルである上記（７）に記載のデータ補正プログラム。 (9) The data correction program according to (7), wherein the information is a lookup table.
　（１０）前記情報は、形状が既知である原器を測定して得られる上記（７）～（９）のいずれか１つに記載のデータ補正プログラム。 (10) The data correction program according to any one of (7) to (9), wherein the information is obtained by measuring a prototype having a known shape.
　（１１）前記原器は、球面原器である上記（１０）に記載のデータ補正プログラム。 (11) The data correction program according to (10), wherein the original device is a spherical original device.
　（１２）前記形状測定装置にはエリアセンサが備えられ、前記所定領域は、前記エリアセンサの撮像領域の一部の領域であり、前記補正値は、前記撮像領域内における前記所定領域の位置とさらに関連付けられ、前記情報は、前記傾斜角度と前記位置と前記補正値とを関連付けた情報であり、前記手順（ｃ）において、前記情報を用いて、前記傾斜角度及び前記位置に対応する補正値が決定される上記（７）～（１１）のいずれか１つに記載のデータ補正プログラム。 (12) The shape measuring device includes an area sensor, the predetermined area is a partial area of the imaging area of the area sensor, and the correction value is a position of the predetermined area in the imaging area. Further, the information is information in which the inclination angle, the position, and the correction value are associated with each other, and the correction value corresponding to the inclination angle and the position using the information in the step (c). The data correction program according to any one of (7) to (11) above, in which is determined.
　（１３）上記（７）～（１２）のいずれか１つに記載のデータ補正プログラムを記録したコンピューター読み取り可能な記録媒体。 (13) A computer-readable recording medium on which the data correction program according to any one of (7) to (12) above is recorded.
　本発明によれば、ワークの測定対象領域が傾斜面であることに起因する高さデータの誤差が傾斜角度に応じて補正されるため、ワークと顕微鏡対物レンズとの相対的な傾きを変化させることなく、ワーク形状を精度良く測定することができる。 According to the present invention, since the error of the height data caused by the measurement target region of the work being an inclined surface is corrected according to the inclination angle, the relative inclination between the work and the microscope objective lens is changed. Therefore, the workpiece shape can be measured with high accuracy.
本発明の第１実施形態に係る形状測定システムの概略構成を示す図である。It is a figure showing a schematic structure of a shape measuring system concerning a 1st embodiment of the present invention. 図１に示される情報処理装置の概略構成を示すブロック図である。It is a block diagram which shows schematic structure of the information processing apparatus shown by FIG. 情報処理装置により実行される高さデータ補正処理の手順を示すフローチャートである。It is a flowchart which shows the procedure of the height data correction process performed by information processing apparatus. ワークの傾斜角度と反射光との関係を示す図である。It is a figure which shows the relationship between the inclination angle of a workpiece | work, and reflected light. 情報処理装置により実行される関数作成処理の手順を示すフローチャートである。It is a flowchart which shows the procedure of the function creation process performed by information processing apparatus. 傾斜角度を算出する処理を説明するための図である。It is a figure for demonstrating the process which calculates an inclination angle. ルックアップテーブルの一例を示す図である。It is a figure which shows an example of a lookup table. 本発明の第２実施形態に係る高さデータ補正処理の手順を示すフローチャートである。It is a flowchart which shows the procedure of the height data correction process which concerns on 2nd Embodiment of this invention.
　以下、図面を参照して、本発明の実施形態を説明する。なお、図面の寸法比率は、説明の都合上、誇張されて実際の比率とは異なる場合がある。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.
　＜第１実施形態＞
　図１は、本発明の第１実施形態に係る形状測定システム１の概略構成を示す図である。 <First Embodiment>
FIG. 1 is a diagram showing a schematic configuration of a shape measuring system 1 according to the first embodiment of the present invention.
　図１に示されるように、本実施形態に係る形状測定システム１は、形状測定装置１０及び情報処理装置２０を備える。 As shown in FIG. 1, the shape measurement system 1 according to this embodiment includes a shape measurement device 10 and an information processing device 20.
　形状測定装置１０は、白色光干渉を用いてワーク表面を測定する。形状測定装置１０は、顕微鏡本体部１１に顕微鏡対物レンズ１２が取り付けられて構成される。顕微鏡対物レンズ１２は、顕微鏡本体部１１から供給される白色光をワーク表面に集光させ、白色光干渉縞を発生させる。また、顕微鏡対物レンズ１２は、ピエゾ素子により光軸方向に移動される。顕微鏡本体部１１の上部にはエリアセンサ１３が備えられ、ワーク表面に白色光を照射することにより発生する白色光干渉縞を撮像する。ピエゾ素子により顕微鏡対物レンズ１２を移動させつつ、エリアセンサ１３により白色光干渉縞を撮像して得られる複数の画像データは、情報処理装置２０に送信される。 The shape measuring apparatus 10 measures the workpiece surface using white light interference. The shape measuring apparatus 10 is configured by attaching a microscope objective lens 12 to a microscope main body 11. The microscope objective lens 12 condenses the white light supplied from the microscope main body 11 on the work surface to generate white light interference fringes. Further, the microscope objective lens 12 is moved in the optical axis direction by a piezoelectric element. An area sensor 13 is provided on the upper part of the microscope main body 11, and images white light interference fringes generated by irradiating the work surface with white light. A plurality of image data obtained by imaging the white light interference fringes by the area sensor 13 while moving the microscope objective lens 12 by the piezo element is transmitted to the information processing apparatus 20.
　情報処理装置２０は、形状測定装置１０の動作を制御するとともに、形状測定装置１０から受信した画像データを解析して、エリアセンサ１３の撮像領域に含まれる画素の高さデータを算出する。また、情報処理装置２０は、データ補正装置として、後述する傾斜角度と誤差を補正するための補正値とを関連付けた情報を用いて、撮像領域に含まれる画素の高さデータを補正する。 The information processing device 20 controls the operation of the shape measuring device 10 and analyzes the image data received from the shape measuring device 10 to calculate the height data of the pixels included in the imaging region of the area sensor 13. Moreover, the information processing apparatus 20 corrects the height data of the pixels included in the imaging region using information in which a tilt angle described later and a correction value for correcting the error are associated as a data correction apparatus.
　図２は、情報処理装置２０の概略構成を示すブロック図である。情報処理装置２０は、ＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）２１、ＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）２２、ＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）２３、ハードディスク２４、入力部２５、表示部２６、及び送受信部２７を有する。これらの各部は、バス２８を介して相互に接続されている。 FIG. 2 is a block diagram illustrating a schematic configuration of the information processing apparatus 20. The information processing apparatus 20 includes a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, a hard disk 24, an input unit 25, a display unit 26, and a transmission / reception unit 27. These units are connected to each other via a bus 28.
　ＣＰＵ２１は、形状測定装置１０から受信した画像データに対して、種々の演算及び処理を実行する。ＣＰＵ２１は、解析部、取得部、算出部、決定部及び補正部として機能する。 The CPU 21 executes various calculations and processes on the image data received from the shape measuring apparatus 10. The CPU 21 functions as an analysis unit, an acquisition unit, a calculation unit, a determination unit, and a correction unit.
　ここで、解析部は、形状測定装置１０から受信した画像データを解析して、画素の高さデータを算出する。取得部は、解析部により算出された各画素の高さデータを取得する。算出部は、取得部により取得された画素の高さデータに基づいて、画素の傾斜角度を算出する。決定部は、ハードディスク２４に記憶された情報を用いて、算出部により算出された傾斜角度に対応する補正値を決定する。補正部は、決定部により決定された補正値を用いて、画素の高さデータを補正する。なお、各部の具体的な処理内容については、後述する。 Here, the analysis unit analyzes the image data received from the shape measuring apparatus 10 and calculates pixel height data. The acquisition unit acquires the height data of each pixel calculated by the analysis unit. The calculation unit calculates the tilt angle of the pixel based on the pixel height data acquired by the acquisition unit. The determination unit determines a correction value corresponding to the tilt angle calculated by the calculation unit using information stored in the hard disk 24. The correction unit corrects the pixel height data using the correction value determined by the determination unit. The specific processing contents of each unit will be described later.
　ＲＯＭ２２は、各種プログラムや各種データを予め記憶する。ＲＡＭ２３は、作業領域として、プログラムやデータを一時的に記憶する。 The ROM 22 stores various programs and various data in advance. The RAM 23 temporarily stores programs and data as a work area.
　ハードディスク２４は、オペレーティングシステムを含む各種プログラムや各種データを格納する。ハードディスク２４には、傾斜角度から補正値を計算する関数が格納されている。 The hard disk 24 stores various programs including the operating system and various data. The hard disk 24 stores a function for calculating a correction value from the tilt angle.
　また、ハードディスク２４は、形状測定装置１０から受信した画像データを解析して画素の高さデータを算出するための解析プログラム、画素の高さデータを取得するための取得プログラム、画素の傾斜角度を算出するための算出プログラム、傾斜角度に対応する補正値を決定するための決定プログラム及び画素の高さデータを補正するための補正プログラムを格納する。 In addition, the hard disk 24 analyzes an image data received from the shape measuring apparatus 10 to calculate pixel height data, an acquisition program for acquiring pixel height data, and a pixel tilt angle. A calculation program for calculation, a determination program for determining a correction value corresponding to the tilt angle, and a correction program for correcting pixel height data are stored.
　入力部２５は、たとえば、キーボード、タッチパネル、及びマウス等のポインティングデバイスであり、各種情報の入力に用いられる。表示部２６は、たとえば、液晶ディスプレイであり、各種情報を表示する。 The input unit 25 is a pointing device such as a keyboard, a touch panel, and a mouse, and is used for inputting various information. The display part 26 is a liquid crystal display, for example, and displays various information.
　送受信部２７は、たとえば、インターフェースであり、形状測定装置１０からの画像データを受信する。また、送受信部２７は、形状測定装置１０の動作を制御するための各種指令を出力する。 The transmission / reception unit 27 is an interface, for example, and receives image data from the shape measuring apparatus 10. Further, the transmission / reception unit 27 outputs various commands for controlling the operation of the shape measuring apparatus 10.
　なお、形状測定装置１０及び情報処理装置２０は、上述した構成要素以外の構成要素を含んでいてもよく、あるいは、上述した構成要素のうちの一部が含まれていなくてもよい。 Note that the shape measuring device 10 and the information processing device 20 may include components other than the above-described components, or some of the above-described components may not be included.
　以上のとおり構成される形状測定システム１では、形状測定装置１０から受信した画像データが、情報処理装置２０により解析され、画像データの各画素の高さデータが算出される。そして、各画素の高さデータが傾斜角度に応じて補正される。以下、図３及び図４を参照して、本実施形態に係る情報処理装置２０の動作について説明する。 In the shape measuring system 1 configured as described above, the image data received from the shape measuring device 10 is analyzed by the information processing device 20, and the height data of each pixel of the image data is calculated. Then, the height data of each pixel is corrected according to the tilt angle. Hereinafter, the operation of the information processing apparatus 20 according to the present embodiment will be described with reference to FIG. 3 and FIG. 4.
　図３は、情報処理装置２０により実行される高さデータ補正処理の手順を示すフローチャートである。なお、図３のフローチャートにより示されるアルゴリズムは、情報処理装置２０のハードディスク２４にプログラムとして記憶されており、ＣＰＵ２１によって実行される。 FIG. 3 is a flowchart showing a procedure of height data correction processing executed by the information processing apparatus 20. Note that the algorithm shown in the flowchart of FIG. 3 is stored as a program in the hard disk 24 of the information processing apparatus 20 and is executed by the CPU 21.
　Ｓ０１では、形状測定装置１０から受信した画像データが解析され、各画素の高さデータが算出される。具体的には、形状測定装置１０から受信した複数の画像データが解析され、白色光干渉縞のピーク強度位置が求められることにより、各画素の高さデータが算出される。たとえば、エリアセンサの撮像領域が２５６×２５６個の画素であるとき、全ての画素について高さデータが算出される。なお、画像データを解析して、画素ごとに高さデータを算出する技術自体は公知な技術であるため、詳細な説明は省略する。 In S01, the image data received from the shape measuring apparatus 10 is analyzed, and the height data of each pixel is calculated. Specifically, the plurality of pieces of image data received from the shape measuring apparatus 10 are analyzed, and the peak intensity position of the white light interference fringe is obtained, whereby the height data of each pixel is calculated. For example, when the imaging area of the area sensor is 256 × 256 pixels, height data is calculated for all pixels. Note that a technique for analyzing the image data and calculating the height data for each pixel is a known technique, and thus detailed description thereof is omitted.
　Ｓ０２では、Ｓ０１において高さデータが算出された複数の画素の中から１つの画素が選択される。そして、当該１つの画素及び当該１つの画素の周辺画素を含む小領域の画素群が選択され、当該画素群の高さデータが取得される。たとえば、２５６×２５６個の画素の中から１つの画素が選択される。そして、当該１つの画素及び当該１つの画素の上下左右４つの画素を含む小領域の画素群が選択され、当該画素群の高さデータが取得される。 In S02, one pixel is selected from the plurality of pixels whose height data has been calculated in S01. Then, a pixel group of a small region including the one pixel and the peripheral pixels of the one pixel is selected, and height data of the pixel group is acquired. For example, one pixel is selected from 256 × 256 pixels. Then, a pixel group of a small region including the one pixel and four pixels above, below, left, and right of the one pixel is selected, and height data of the pixel group is acquired.
　Ｓ０３では、Ｓ０２において高さデータが取得された画素群の高さデータにより、Ｓ０２において選択された１つの画素の傾斜角度が算出される。具体的には、たとえば、画素群の高さデータを用いて画素のＸ方向の傾斜角度とＹ方向の傾斜角度とが算出される。なお、Ｘ方向及びＹ方向は、形状測定装置１０の光軸（Ｚ軸）に垂直なステージの移動方向を示す。 In S03, the inclination angle of one pixel selected in S02 is calculated from the height data of the pixel group from which the height data was acquired in S02. Specifically, for example, the tilt angle in the X direction and the tilt angle in the Y direction of the pixel are calculated using the height data of the pixel group. Note that the X direction and the Y direction indicate the moving direction of the stage perpendicular to the optical axis (Z axis) of the shape measuring apparatus 10.
　Ｓ０４では、ハードディスク２４に記憶されている関数を用いて、Ｓ０３において算出された傾斜角度に対応する補正値が決定される。 In S04, a correction value corresponding to the tilt angle calculated in S03 is determined using the function stored in the hard disk 24.
　補正値ｆ（ｘt，ｙt）を決定する関数は、画素のＸ方向の傾斜角度をｘt、Ｙ方向の傾斜角度をｙtとしたとき、たとえばｎ次の多項式関数を用いて、下記（１）式のように表される。ここで、ａijは傾斜補正の係数配列である。（１）式の関数がハードディスク２４に記憶されている。下記（１）式のｘtにＸ方向の傾斜角度を、ｙtにＹ方向の傾斜角度をそれぞれ代入することにより、補正値ｆが決定される。 The function for determining the correction value f (x t , y t ) is, for example, an n-order polynomial function, where x t is the tilt angle in the X direction and y t is the tilt angle in the Y direction. It is expressed as (1). Here, a ij is an inclination correction coefficient array. The function of equation (1) is stored in the hard disk 24. The inclination angle of the X direction x t of the following formula (1), by substituting each inclination angle of the Y-direction in y t, the correction value f is determined.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　Ｓ０５では、Ｓ０４において決定された補正値ｆを用いて、Ｓ０２において取得された画素の高さデータが補正される。具体的には、高さデータから補正値が加算または減算される。 In S05, the pixel height data acquired in S02 is corrected using the correction value f determined in S04. Specifically, the correction value is added or subtracted from the height data.
　Ｓ０６では、すべての画素の高さデータの補正が終了したか否かが判断される。具体的には、たとえば、エリアセンサ１３に含まれる２５６×２５６個の画素の高さデータが、すべて補正されたか否かが判断される。 In S06, it is determined whether or not the correction of the height data of all the pixels has been completed. Specifically, for example, it is determined whether or not the height data of 256 × 256 pixels included in the area sensor 13 has been corrected.
　すべての画素の高さデータの補正が終了していないと判断される場合（Ｓ０６：ＮＯ）、Ｓ０２の処理に戻る。そして、エリアセンサ１３のすべての画素の高さデータが補正されるまで、Ｓ０２以下の処理が繰り返される。 When it is determined that the correction of the height data of all the pixels has not been completed (S06: NO), the process returns to S02. And the process after S02 is repeated until the height data of all the pixels of the area sensor 13 are corrected.
　一方、Ｓ０６において、すべての画素の高さデータの補正が終了したと判断される場合（Ｓ０６：ＹＥＳ）、処理が終了される。 On the other hand, when it is determined in S06 that the correction of the height data of all the pixels has been completed (S06: YES), the process is terminated.
　以上のとおり、図３に示されるフローチャートの処理によれば、エリアセンサ１３の撮像領域に含まれる画素の高さデータが、傾斜角度に基づいて補正される。 As described above, according to the processing of the flowchart shown in FIG. 3, the height data of the pixels included in the imaging region of the area sensor 13 is corrected based on the tilt angle.
　次に、図４を参照して、データ補正処理の効果について説明する。図４は、ワークＷの傾斜角度と反射光との関係を示す図である。 Next, the effect of the data correction process will be described with reference to FIG. FIG. 4 is a diagram showing the relationship between the tilt angle of the workpiece W and the reflected light.
　図４（Ａ）に示されるように、ワーク表面に対して光軸Ｓが垂直のとき、顕微鏡対物レンズ１２により集光されワーク表面で反射される白色光Ｌ１については、すべての反射光が顕微鏡対物レンズ１２に戻る。 As shown in FIG. 4A, when the optical axis S is perpendicular to the workpiece surface, for the white light L1 collected by the microscope objective lens 12 and reflected by the workpiece surface, all reflected light is reflected by the microscope. Return to the objective lens 12.
　一方、図４（Ｂ）及び（Ｃ）に示されるように、ワーク表面が光軸Ｓの垂直方向に対して傾斜しているとき、顕微鏡対物レンズ１２により集光されワーク表面で反射される白色光Ｌ２，Ｌ３については、一部の反射光は顕微鏡対物レンズ１２に戻らず、これに起因する高さデータの測定誤差が生じる。なお、ワーク表面の傾斜角度が大きいほど、測定誤差は大きくなる。 On the other hand, as shown in FIGS. 4B and 4C, when the work surface is inclined with respect to the direction perpendicular to the optical axis S, the light is collected by the microscope objective lens 12 and reflected by the work surface. As for the lights L2 and L3, a part of the reflected light does not return to the microscope objective lens 12, and a measurement error of height data resulting from this occurs. The measurement error increases as the tilt angle of the workpiece surface increases.
　本実施形態のデータ補正処理によれば、各画素に対応するワークＷの傾斜角度に応じて各画素の高さデータが補正されるため、ワークＷの測定対象領域が傾斜面であっても、ワーク形状を精度良く測定することができる。 According to the data correction process of the present embodiment, since the height data of each pixel is corrected according to the inclination angle of the workpiece W corresponding to each pixel, even if the measurement target region of the workpiece W is an inclined surface, The workpiece shape can be measured with high accuracy.
　また、本実施形態の形状測定システム１によれば、ワークＷと顕微鏡対物レンズ１２との相対的な傾きを変化させることなく、ワーク形状を精度良く測定することができる。 Further, according to the shape measurement system 1 of the present embodiment, the workpiece shape can be measured with high accuracy without changing the relative inclination between the workpiece W and the microscope objective lens 12.
　以上のとおり、ハードディスク２４に記憶された関数を用いて、ワークＷの高さデータを補正する処理について述べた。以下では、関数を作成する処理について説明する。 As described above, the processing for correcting the height data of the workpiece W using the function stored in the hard disk 24 has been described. Below, the process which produces a function is demonstrated.
　図５は、情報処理装置２０により実行される関数作成処理の手順を示すフローチャートである。なお、図５のフローチャートにより示されるアルゴリズムは、情報処理装置２０のハードディスク２４にプログラムとして記憶されており、ＣＰＵ２１によって実行される。 FIG. 5 is a flowchart showing the procedure of the function creation process executed by the information processing apparatus 20. Note that the algorithm shown in the flowchart of FIG. 5 is stored as a program in the hard disk 24 of the information processing apparatus 20 and is executed by the CPU 21.
　関数の作成に先立って、形状が既知である球面原器が用意され、形状測定装置１０により球面原器の複数の領域が測定される。 Prior to the creation of the function, a spherical original device having a known shape is prepared, and a plurality of areas of the spherical original device are measured by the shape measuring apparatus 10.
　Ｓ１１では、形状測定装置１０により球面原器を測定して得られた複数の画像データが解析され、球面原器の複数の領域の高さデータが算出される。 In S11, a plurality of image data obtained by measuring the spherical original device by the shape measuring apparatus 10 are analyzed, and height data of a plurality of regions of the spherical original device are calculated.
　Ｓ１２では、Ｓ１１において算出された複数の領域の高さデータについて、当該高さデータと球面原器の実際の高さデータとの差分が算出され、高さデータの補正値が画素ごとに算出される。ここで、実際の高さデータは、球面原器の半径及び測定位置から幾何学的に算出される。 In S12, for the height data of the plurality of areas calculated in S11, a difference between the height data and the actual height data of the spherical original device is calculated, and a correction value of the height data is calculated for each pixel. The Here, the actual height data is geometrically calculated from the radius of the spherical prototype and the measurement position.
　Ｓ１３では、Ｓ１２において補正値が算出された各画素について、当該画素に対応する領域の傾斜角度が、球面原器の半径及び測定位置から幾何学的に算出される。具体的には、球面原器Ｂの接平面Ｐの法線ベクトルＶを算出することにより、傾斜角度が算出される（図６参照）。なお、本実施形態とは異なり、傾斜角度は、図３のＳ０３と同様に、周辺画素の高さデータを用いて算出されてもよい。この場合、高周波除去フィルタや微分処理が用いられてもよい。 In S13, for each pixel for which the correction value has been calculated in S12, the inclination angle of the region corresponding to the pixel is geometrically calculated from the radius of the spherical prototype and the measurement position. Specifically, the inclination angle is calculated by calculating the normal vector V of the tangential plane P of the spherical original device B (see FIG. 6). Unlike the present embodiment, the tilt angle may be calculated using the height data of the surrounding pixels, as in S03 of FIG. In this case, a high frequency removal filter or differentiation processing may be used.
　Ｓ１４では、Ｓ１２及びＳ１３において算出された補正値及び傾斜角度に基づいて、補正値が傾斜角度の関数として定義される。たとえば、ｎ次の多項式近似が行われ、上述した（１）式に示される係数配列ａｉｊが算出される。なお、（１）式ではｎ次の多項式が記載されているが、関数として、Ｚｅｒｎｉｋｅ多項式が用いられてもよい。 In S14, the correction value is defined as a function of the tilt angle based on the correction value and the tilt angle calculated in S12 and S13. For example, n-th order polynomial approximation is performed, and the coefficient array aij shown in the above equation (1) is calculated. Note that although an n-th order polynomial is described in the expression (1), a Zernike polynomial may be used as a function.
　Ｓ１５では、Ｓ１４において算出された関数がハードディスク２４に記憶される。 In S15, the function calculated in S14 is stored in the hard disk 24.
　以上のとおり、本実施形態によれば、球面原器を測定することにより、傾斜角度から補正値を算出する関数が作成される。 As described above, according to the present embodiment, a function for calculating a correction value from an inclination angle is created by measuring a spherical prototype.
　＜変形例＞
　なお、上述した実施形態では、傾斜角度から補正値を計算する関数を用いて、各画素の傾斜角度に対応する補正値が決定された。しかしながら、ルックアップテーブルを用いて、各画素の傾斜角度に対応する補正値が決定されてもよい。 <Modification>
In the above-described embodiment, the correction value corresponding to the inclination angle of each pixel is determined using a function for calculating the correction value from the inclination angle. However, a correction value corresponding to the tilt angle of each pixel may be determined using a lookup table.
　図７は、ルックアップテーブル１００の一例を示す図である。ルックアップテーブル１００は、図７に示されるように、画素のＸ方向及びＹ方向の傾斜角度と補正値とを対応付ける情報である。たとえば、図３のＳ０３において算出された傾斜角度がＸ方向に対して３１°、Ｙ方向に対して３０°であるとき、ルックアップテーブル１００から補正値は６ｎｍと決定される。なお、対応する傾斜角度がルックアップテーブル１００に存在しない場合は、内挿により補正値が決定され得る。内挿は、たとえば、数値Ｎ１と数値Ｎ２との間が直線的であるとして、数値Ｎ１と数値Ｎ２との間の数値を算出する線形補間である。 FIG. 7 is a diagram illustrating an example of the lookup table 100. As shown in FIG. 7, the look-up table 100 is information that associates inclination angles of pixels in the X direction and Y direction with correction values. For example, when the tilt angle calculated in S03 of FIG. 3 is 31 ° with respect to the X direction and 30 ° with respect to the Y direction, the correction value is determined to be 6 nm from the lookup table 100. When the corresponding inclination angle does not exist in the lookup table 100, the correction value can be determined by interpolation. The interpolation is, for example, linear interpolation for calculating a numerical value between the numerical value N1 and the numerical value N2, assuming that the numerical value N1 and the numerical value N2 are linear.
　＜第２実施形態＞
　次に、図８を参照して、本発明の第２実施形態について説明する。本実施形態は、各画素の高さデータを補正する補正値に、エリアセンサ１３の撮像領域内における画素の位置がさらに関連付けられている実施形態である。 <Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the position of the pixel in the imaging region of the area sensor 13 is further associated with a correction value for correcting the height data of each pixel.
　図８は、本実施形態に係る高さデータ補正処理の手順を示すフローチャートである。Ｓ２１～Ｓ２３は、図３のＳ０１～Ｓ０３と同様であるため説明を省略する。 FIG. 8 is a flowchart showing a procedure of height data correction processing according to the present embodiment. Since S21 to S23 are the same as S01 to S03 in FIG.
　Ｓ２４では、ハードディスク２４に記憶されている傾斜角度と画素の位置と補正値とを関連付けた関数を用いて、Ｓ２３において算出された傾斜角度及び画素の位置に対応する補正値が決定される。 In S24, a correction value corresponding to the tilt angle and pixel position calculated in S23 is determined using a function that associates the tilt angle, the pixel position, and the correction value stored in the hard disk 24.
　補正値ｇ（ｘt，ｙt，ｘp，ｙp）を決定する関数は、画素のＸ方向の傾斜角度をｘt、Ｙ方向の傾斜角度をｙt、画素のＸ座標をｘp、画素のＹ座標をｙpとしたとき、たとえば、ｎ次の多項式関数を用いて、下記（２）式のように表せる。ここで、ｂijklは傾斜及び位置補正の多項式の係数配列である。（２）式の関数がハードディスク２４に記憶されている。下記（２）式のｘtにＸ方向の傾斜角度を、ｙtにＹ方向の傾斜角度を、ｘpに画素のＸ座標を、ｙpに画素のＹ座標をそれぞれ代入することにより、補正値ｇが決定される。なお、下記（２）式は、（１）式と同様に、球面原器を測定して算出される。 The function for determining the correction value g (x t , y t , x p , y p ) is such that the tilt angle of the pixel in the X direction is x t , the tilt angle in the Y direction is y t , and the X coordinate of the pixel is x p , when the Y coordinate of the pixel was set to y p, for example, by using the n-order polynomial function can be expressed as the following equation (2). Here, b ijkl is a coefficient array of polynomials for inclination and position correction. The function of equation (2) is stored in the hard disk 24. The inclination angle of the following (2) X direction x t of formula, the inclination angle of the Y-direction in y t, the X coordinate of the pixel in x p, by substituting the Y coordinate of the pixel, respectively y p, correction The value g is determined. The following equation (2) is calculated by measuring a spherical original device, similarly to equation (1).
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　Ｓ２５及びＳ２６は、図３のＳ０５及びＳ０６と同様であるため説明を省略する。 S25 and S26 are the same as S05 and S06 in FIG.
　以上のとおり、本実施形態によれば、ワークＷの測定対象領域が傾斜面であることに起因する誤差に加え、エリアセンサ１３の測定領域内における画素の位置に起因する誤差も補正することができる。画素の位置に起因する誤差は、傾斜角度が大きいほど顕著になり、同じ傾斜角度であっても、エリアセンサ１３の中央部に位置する画素の補正値とエリアセンサ１３の角部に位置する画素の補正値とが異なる場合がある。本実施形態によれば、ワークＷの傾斜角度が大きい場合であっても、ワーク形状を精度良く測定することができる。 As described above, according to the present embodiment, in addition to the error caused by the measurement target region of the workpiece W being an inclined surface, the error caused by the position of the pixel in the measurement region of the area sensor 13 can be corrected. it can. The error due to the position of the pixel becomes more prominent as the tilt angle becomes larger. Even if the tilt angle is the same, the correction value of the pixel located at the center of the area sensor 13 and the pixel located at the corner of the area sensor 13 The correction value may be different. According to this embodiment, even when the tilt angle of the workpiece W is large, the workpiece shape can be accurately measured.
　なお、第１実施形態の変形例と同様に、ルックアップテーブルにより、傾斜角度と画素の位置と補正値とが関連付けられていてもよい。 Note that, similarly to the modification of the first embodiment, the tilt angle, the pixel position, and the correction value may be associated with each other by a lookup table.
　本発明は、上述した実施形態のみに限定されるものではなく、特許請求の範囲内において、種々改変することができる。 The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.
　たとえば、上述した第１及び第２実施形態では、エリアセンサ１３の撮像領域に含まれる画素の高さデータが１つの画素ごとに補正された。しかしながら、エリアセンサ１３の撮像領域（たとえば２５６×２５６個の画素）が複数のブロック（たとえば８×８＝６４ブロック）に分割され（たとえば１ブロックは３２×３２個の画素）、ブロック単位で高さデータが補正されてもよい。この場合、データ処理速度が向上する効果が挙げられる。 For example, in the first and second embodiments described above, the height data of the pixels included in the imaging region of the area sensor 13 is corrected for each pixel. However, the imaging area of the area sensor 13 (for example, 256 × 256 pixels) is divided into a plurality of blocks (for example, 8 × 8 = 64 blocks) (for example, one block is 32 × 32 pixels), The data may be corrected. In this case, there is an effect that the data processing speed is improved.
　また、上述した第１及び第２実施形態では、各画素におけるワークＷの傾斜角度は、画素の高さデータに基づいて算出された。しかしながら、ワークＷの所定領域の傾斜角度は、ワークのＣＡＤデータを用いて算出されてもよい。さらには、測定対象領域が設計式で表現される場合、当該設計式が用いられてもよい。 In the first and second embodiments described above, the inclination angle of the workpiece W in each pixel is calculated based on the pixel height data. However, the inclination angle of the predetermined area of the workpiece W may be calculated using CAD data of the workpiece. Furthermore, when the measurement target region is expressed by a design formula, the design formula may be used.
　また、上述した第１及び第２実施形態では、球面原器が用いられていた。しかしながら、原器には、形状が既知である凹凸面や傾斜角が既知の傾斜面を有する原器が用いられてもよい。 Further, in the first and second embodiments described above, a spherical original device is used. However, a prototype having an uneven surface with a known shape or an inclined surface with a known tilt angle may be used as the prototype.
　また、上述した第１及び第２実施形態では、ハードディスク２４に記憶されたプログラムをＣＰＵ２１が実行することによって、高さデータが補正された。しかしながら、高さデータを補正する処理はＦＰＧＡ（Ｆｉｅｌｄ　Ｐｒｏｇｒａｍｍａｂｌｅ　Ｇａｔｅ　Ａｒｒａｙ）等のハードウエア回路によって実行されてもよい。この場合、並列処理により複数の画素の高さデータが同時に補正される。 In the first and second embodiments described above, the height data is corrected by the CPU 21 executing the program stored in the hard disk 24. However, the process of correcting the height data may be executed by a hardware circuit such as an FPGA (Field Programmable Gate Array). In this case, the height data of a plurality of pixels is corrected simultaneously by parallel processing.
　また、上述した第１及び第２実施形態に係る形状測定システム１における各種処理を行う手段および方法は、専用のハードウエア回路、またはプログラムされたコンピューターのいずれによっても実現することが可能である。上記プログラムは、たとえば、フレキシブルディスクおよびＣＤ－ＲＯＭ等のコンピューター読み取り可能な記録媒体によって提供されてもよいし、インターネット等のネットワークを介してオンラインで提供されてもよい。この場合、コンピューター読み取り可能な記録媒体に記録されたプログラムは、通常、ハードディスク等の記憶部に転送され記憶される。また、上記プログラムは、単独のアプリケーションソフトとして提供されてもよいし、形状測定システム１の一機能としてその装置のソフトウエアに組み込まれてもよい。 The means and method for performing various processes in the shape measurement system 1 according to the first and second embodiments described above can be realized by either a dedicated hardware circuit or a programmed computer. The program may be provided by a computer-readable recording medium such as a flexible disk and a CD-ROM, or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. The program may be provided as a single application software, or may be incorporated in the software of the apparatus as one function of the shape measurement system 1.
１　形状測定システム、
１０　形状測定装置、
１１　顕微鏡本体部、
１２　顕微鏡対物レンズ、
１３　エリアセンサ、
２０　情報処理装置、
２１　ＣＰＵ、
２２　ＲＯＭ、
２３　ＲＡＭ、
２４　ハードディスク、
２５　入力部、
２６　表示部、
２７　送受信部、
２８　バス、
１００　ルックアップテーブル、
Ｗ　ワーク。 1 shape measurement system,
10 shape measuring device,
11 Microscope body,
12 microscope objective lens,
13 Area sensor,
20 information processing device,
21 CPU,
22 ROM,
23 RAM,
24 hard disk,
25 input section,
26 display section,
27 Transmitter / receiver,
28 Bus,
100 lookup table,
W Work.

Claims (13)

  1. 　光学式の形状測定装置により測定されるワーク上の小領域の傾斜角度と当該小領域の高さデータを補正するための補正値とを関連付けた情報を記憶している記憶部と、
    　前記形状測定装置によりワークを測定して得られる所定領域の高さデータを取得する取得部と、
    　前記取得部により高さデータが取得された前記所定領域の傾斜角度を算出する算出部と、
    　前記記憶部に記憶されている前記情報を用いて、前記算出部により算出された前記傾斜角度に対応する補正値を決定する決定部と、
    　前記決定部により決定された前記補正値を用いて、前記取得部により取得された高さデータを補正する補正部と、
    　を有するデータ補正装置。     A storage unit that stores information associating the inclination angle of the small area on the workpiece measured by the optical shape measuring apparatus and the correction value for correcting the height data of the small area;
    An acquisition unit for acquiring height data of a predetermined region obtained by measuring a workpiece by the shape measuring device;
    A calculation unit that calculates an inclination angle of the predetermined region from which height data has been acquired by the acquisition unit;
    A determination unit that determines a correction value corresponding to the tilt angle calculated by the calculation unit, using the information stored in the storage unit;
    Using the correction value determined by the determination unit, a correction unit that corrects the height data acquired by the acquisition unit;
    A data correction apparatus.
  2. 　前記情報は、関数である請求項１に記載のデータ補正装置。 The data correction apparatus according to claim 1, wherein the information is a function.
  3. 　前記情報は、ルックアップテーブルである請求項１に記載のデータ補正装置。 The data correction apparatus according to claim 1, wherein the information is a lookup table.
  4. 　前記情報は、形状が既知である原器を測定して得られる請求項１～３のいずれか１項に記載のデータ補正装置。 The data correction device according to any one of claims 1 to 3, wherein the information is obtained by measuring a prototype having a known shape.
  5. 　前記原器は、球面原器である請求項４に記載のデータ補正装置。 5. The data correction apparatus according to claim 4, wherein the original device is a spherical original device.
  6. 　前記形状測定装置にはエリアセンサが備えられ、前記所定領域は、前記エリアセンサの撮像領域の一部の領域であり、
    　前記補正値は、前記撮像領域内における前記所定領域の位置とさらに関連付けられ、
    　前記情報は、前記傾斜角度と前記位置と前記補正値とを関連付けた情報であり、
    　前記決定部は、前記情報を用いて、前記傾斜角度及び前記位置に対応する補正値を決定する請求項１～５のいずれか１項に記載のデータ補正装置。     The shape measuring device includes an area sensor, and the predetermined area is a partial area of an imaging area of the area sensor,
    The correction value is further associated with the position of the predetermined area in the imaging area,
    The information is information associating the tilt angle, the position, and the correction value,
    6. The data correction apparatus according to claim 1, wherein the determination unit determines a correction value corresponding to the tilt angle and the position using the information.
  7. 　光学式の形状測定装置によりワークを測定して得られる所定領域の高さデータを取得する手順（ａ）と、
    　前記手順（ａ）において高さデータが取得された前記所定領域の傾斜角度を算出する手順（ｂ）と、
    　前記形状測定装置により測定されるワーク上の小領域の傾斜角度と当該小領域の高さデータを補正するための補正値とを関連付けた情報を用いて、前記手順（ｂ）において算出された前記傾斜角度に対応する補正値を決定する手順（ｃ）と、
    　前記手順（ｃ）において決定された前記補正値を用いて、前記手順（ａ）において取得された高さデータを補正する手順（ｄ）と、
    　をコンピューターに実行させるデータ補正プログラム。     A procedure (a) for obtaining height data of a predetermined area obtained by measuring a workpiece with an optical shape measuring device;
    A procedure (b) for calculating an inclination angle of the predetermined area from which the height data is acquired in the procedure (a);
    The information calculated in the step (b) using information that associates the inclination angle of the small area on the workpiece measured by the shape measuring apparatus and the correction value for correcting the height data of the small area. A procedure (c) for determining a correction value corresponding to the tilt angle;
    Using the correction value determined in the step (c), the step (d) for correcting the height data acquired in the step (a);
    A data correction program that causes a computer to execute.
  8. 　前記情報は、関数である請求項７に記載のデータ補正プログラム。 The data correction program according to claim 7, wherein the information is a function.
  9. 　前記情報は、ルックアップテーブルである請求項７に記載のデータ補正プログラム。 The data correction program according to claim 7, wherein the information is a lookup table.
  10. 　前記情報は、形状が既知である原器を測定して得られる請求項７～９のいずれか１項に記載のデータ補正プログラム。 The data correction program according to any one of claims 7 to 9, wherein the information is obtained by measuring a prototype having a known shape.
  11. 　前記原器は、球面原器である請求項１０に記載のデータ補正プログラム。 The data correction program according to claim 10, wherein the original device is a spherical original device.
  12. 　前記形状測定装置にはエリアセンサが備えられ、前記所定領域は、前記エリアセンサの撮像領域の一部の領域であり、
    　前記補正値は、前記撮像領域内における前記所定領域の位置とさらに関連付けられ、
    　前記情報は、前記傾斜角度と前記位置と前記補正値とを関連付けた情報であり、
    　前記手順（ｃ）において、前記情報を用いて、前記傾斜角度及び前記位置に対応する補正値が決定される請求項７～１１のいずれか１項に記載のデータ補正プログラム。     The shape measuring device includes an area sensor, and the predetermined area is a partial area of an imaging area of the area sensor,
    The correction value is further associated with the position of the predetermined area in the imaging area,
    The information is information associating the tilt angle, the position, and the correction value,
    The data correction program according to any one of claims 7 to 11, wherein in the step (c), a correction value corresponding to the tilt angle and the position is determined using the information.
  13. 　請求項７～１２のいずれか１項に記載のデータ補正プログラムを記録したコンピューター読み取り可能な記録媒体。 A computer-readable recording medium on which the data correction program according to any one of claims 7 to 12 is recorded.
PCT/JP2012/074504 2011-12-07 2012-09-25 Data correction apparatus and data correction program WO2013084565A1 (en)

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JP2018162996A (en) * 2017-03-24 2018-10-18 株式会社ミツトヨ Relation identifying method, relation identifying device, relation identifying program, correction method, correction device, and correction program

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JP2018162996A (en) * 2017-03-24 2018-10-18 株式会社ミツトヨ Relation identifying method, relation identifying device, relation identifying program, correction method, correction device, and correction program

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