Contour shape measuring apparatus and method

Abstract

This invention provides a contour shape measuring device and a contour shape measuring method that can more appropriately adjust the posture of the object to be measured. [Solution] The contour shape measuring device of the present invention is a device that projects parallel light onto the peripheral edge of a disc-shaped object to be measured WK from the tangential direction of the outer circumference, and measures the contour shape of the peripheral edge based on a shadow image of the peripheral edge captured by the shadow of the peripheral edge caused by the parallel light, comprising at least three first to third support members 4-1 to 4-3 for supporting the object to be measured WK from below at at least three points, and controls the first to third support members 4-1 to 4-3 so that the parallel light and the surface of the object to be measured WK are parallel along the direction of projection, and the first to third support members 4-1 to 4-3 are equipped with first to third movement mechanisms 41-1 to 1-3 for moving the first to third support positions of the object to be measured WK in the vertical direction, and in the control, the first to third movement mechanisms 41-1 to 41-3 are controlled individually.

Description

Technical Field

[0001] The present invention relates to a contour shape measuring device and a contour shape measuring method for measuring a contour shape of a disk-shaped measurement object.

Background Art

[0002] In a device that measures the contour shape of a measurement object based on a shadow image obtained by imaging a shadow (image) of a peripheral edge portion of a disk-shaped measurement object generated by applying parallel light from the tangential direction of the outer periphery to the peripheral edge portion, in order to accurately measure the contour shape, it is necessary to set the parallel light and each of the front and back surfaces of the measurement object to be parallel to each other. For example, Patent Document 1 discloses a technique for adjusting the inclination of parallel light (the inclination of the light projection direction of the parallel light) with respect to a measurement object placed on a stage.

[0003] The shape measuring device disclosed in this Patent Document 1 includes a light projecting means for projecting parallel light onto an end portion of a disk-shaped measurement object, an imaging means for imaging a projected image of the end portion of the measurement object from a direction facing the light projection direction of the light projecting means, an optical system holding member for holding the light projecting means and the imaging means, an optical system driving means for driving the optical system holding member to change the inclination of the light projection direction with respect to the surface of the measurement object, an inclination index detecting means for detecting an index of the degree of inclination of the measurement object with respect to the light projection direction, and a first inclination adjusting means for adjusting the inclination of the light projection direction with respect to the surface of the measurement object by controlling the optical system driving means according to the detection result of the index of the degree of inclination. The inclination index detecting means is a displacement detecting means for detecting the position of the surface of the measurement object in a direction orthogonal to the light projection direction at a plurality of observation positions along the light projection direction while being held with respect to the optical system holding member. The first inclination adjusting means adjusts the inclination of the light projection direction in a direction approaching a preset target positional relationship of the positions of the surface of the measurement object in the direction orthogonal to the light projection direction at the plurality of observation positions, and measures the shape of the end face of the measurement object based on the projected image obtained by the imaging means.

Prior Art Documents

[0004] [Patent Document 1] Patent No. 4897658 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, the shape measuring device disclosed in Patent Document 1 adjusts the inclination of the light projection direction relative to the surface of the object to be measured by rotating an optical system holding member that holds the light projection means and imaging means. Therefore, the mounting accuracy when attaching the light projection means and imaging means to the optical system holding member before adjusting the inclination of the light projection direction affects the measurement accuracy. Furthermore, in the shape measuring device disclosed in Patent Document 1, the first tilt adjustment means can only adjust one degree of freedom in a direction perpendicular to the light projection direction. Also, in order to adjust the inclination of the light projection direction after attaching the light projection means and imaging means to the optical system holding member, if the optical axis of the light projection means and imaging means cannot be adjusted with respect to the object to be measured using the first tilt adjustment means, the light projection means and imaging means must be reattached to the optical system holding member.

[0006] This invention was made in view of the above circumstances, and its purpose is to provide a contour shape measuring device and a contour shape measuring method that can more appropriately adjust the posture of the object to be measured. [Means for solving the problem]

[0007] As a result of various studies, the inventors have found that the above objective can be achieved by the present invention as described below. That is, a contour shape measuring device according to one aspect of the present invention is a device that projects parallel light onto the peripheral edge of a disc-shaped object to be measured from the tangential direction of the outer circumference, images the shadow of the peripheral edge produced by the parallel light, and measures the contour shape of the peripheral edge based on the imaged shadow of the peripheral edge, comprising at least three first to third support members for supporting the object to be measured from below at at least three points, and a control unit that controls the first to third support members based on the shadow image of the peripheral edge so that the parallel light and the surface of the object to be measured are parallel along the projection direction, wherein the first to third support members are equipped with first to third movement mechanisms that move the first to third support positions of the object to be measured in the vertical direction, and the control unit controls the first to third movement mechanisms individually.

[0008] Such a contour shape measuring device supports the object to be measured from below at at least three points with at least first to third support members, and individually controls the first to third movement mechanisms of the first to third support members that move the first to third support positions of the object to be measured in the vertical direction. Therefore, there is no need to reattach the light-emitting unit and the imaging unit, and the posture of the object to be measured can be adjusted with two degrees of freedom, allowing for more appropriate adjustment of the posture of the object to be measured.

[0009] In another embodiment, in the contour shape measuring device described above, the control unit individually controls the first to third moving mechanisms so that, when measuring the contour shape of a reference measurement target whose contour shape is known, the difference between the known contour shape and the contour shape of the measurement result is minimized in order to make them parallel.

[0010] Such a contour shape measuring device can calibrate the first to third support positions of the first to third support members using a reference measurement target whose contour shape is known, so that the parallel light and the surface of the measurement target are parallel along the direction of light projection.

[0011] In another embodiment, in the contour shape measuring device described above, the contour shape of the peripheral portion is divided into a plurality of parts, one or more parameters are associated with each part, and the control unit individually controls the first to third moving mechanisms based on the difference between each reference value of the one or more parameters in the known contour shape and each measured value of the one or more parameters in the contour shape of the measurement result.

[0012] Such a contour shape measuring device can individually control the first to third moving mechanisms based on the difference between each reference value and each measured value for each of the one or more parameters.

[0013] In another embodiment, in the contour shape measuring device described above, the contour shape of the peripheral portion is divided into a plurality of parts, one or more parameters are associated with each part, and the control unit individually controls the first to third moving mechanisms so that the difference between the reference value of one of the plurality of parameters in the known contour shape and the measured value of the one parameter in the contour shape of the measurement result is minimized.

[0014] Such contour shape measuring devices can be calibrated using one of several parameters, thus simplifying the calibration process.

[0015] In another embodiment, in the contour shape measuring device described above, the first to third support members are arranged such that the first to third support positions are located at the vertices of a triangle, the first and second support members are positioned relatively close to the parallel light, the third support member is positioned relatively far from the parallel light, and the control unit controls one of the first and second movement mechanisms based on the difference, a first movement control that controls the other of the first and second movement mechanisms based on the difference, and the third movement mechanism based on the difference. The third movement control is executed sequentially, and after the execution of the third movement control, the process returns to the first movement control and the first to third movement controls are executed sequentially. While the first to third movement controls are being executed sequentially, after the execution of each movement control of the first to third movement controls, before executing the next movement control, it is determined whether the value based on the difference is less than or equal to an allowable value. If the result of the determination is that the value based on the difference is less than or equal to an allowable value, the process ends without executing the next movement control. If the result of the determination is that the value based on the difference is not less than or equal to an allowable value, the next movement control is executed.

[0016] Such a contour shape measuring device can be calibrated more reliably because it cyclically and sequentially performs the first to third movement processes until the value based on the difference falls below an acceptable value.

[0017] In another embodiment, in the contour shape measuring device described above, the first to third support members are arranged such that the first to third support positions are located at the vertices of a triangle, the first and second support members are positioned relatively close to the parallel light, and the third support member is positioned relatively far from the parallel light, and the control unit alternately performs a first movement control to control one of the first and second movement mechanisms, and a second movement control to control the other of the first and second movement mechanisms, until the value based on the difference between a reference value of one of the multiple parameters in the known contour shape and the measured value of the one parameter in the contour shape of the measurement result is less than or equal to an allowable value.

[0018] Calibration can often be performed by adjusting the first and second support positions of the first and second support members, which are positioned relatively close to the parallel light. The contour shape measuring device performs the first and second movement processes alternately until the value based on the difference becomes less than or equal to the allowable value, thus enabling calibration in a shorter time.

[0019] In another embodiment, in the contour shape measuring device described above, the first to third support members are arranged such that the length of the first line segment connecting the first support position and the second support position is shorter than the length of the second line segment connecting the first support position and the third support position, and the first to third support members are located at the vertices of an isosceles triangle with the first line segment as the base, the first and second support members are positioned relatively close to the parallel light, and the third support member is positioned relatively far from the parallel light.

[0020] When the disc-shaped object to be measured is relatively thin, a long distance between the support positions may cause the object to bend. If the object bends at the periphery where the parallel light is projected, the measurement accuracy of the contour shape of the periphery will deteriorate. For this reason, it is preferable that the distance between the first and second support positions that support the periphery where the parallel light is projected is short. When the first to third support members are arranged so that the first to third support positions are located at the vertices of an equilateral triangle, the distances between each support position at the first to third support positions become equal. However, the contour shape measuring device arranges the first to third support members so that they are located at the vertices of an isosceles triangle with the line segment connecting the first support position and the second support position as its base. Therefore, the distance between the support positions of the first and second support positions (12th distance) can be made shorter than the distance between the support positions of the first and third support positions (13th distance) and the distance between the support positions of the second and third support positions (23rd distance). This reduces the risk of deflection and reduces the deterioration of measurement accuracy.

[0021] In another embodiment, in the contour shape measuring device described above, the first to third support members further include first to third support claw members having inclined first to third support surfaces so as to make point contact with the periphery of the object to be measured, the first to third support members are arranged such that the first to third support positions are located at the vertices of a triangle and the first to third support surfaces face inward of the triangle, and the first to third moving mechanisms are connected to the first to third support claw members and move the first to third support claw members in the vertical direction.

[0022] In this type of contour shape measuring device, the first to third support members are arranged such that their inclined first to third support surfaces face inward towards the triangle. Therefore, when the first to third support members are individually controlled in the vertical direction, the object to be measured can be supported more reliably by the first to third support members, and the risk of the object to be measured deviating from the support of the first to third support members can be reduced.

[0023] Another aspect of the present invention relates to a contour shape measurement method, which involves projecting parallel light onto the peripheral edge of a disc-shaped object to be measured from a tangential direction of the outer circumference, imaging the shadow of the peripheral edge caused by the parallel light, and measuring the contour shape of the peripheral edge based on the image of the shadow of the peripheral edge, comprising: a support step of supporting the object to be measured from below at at least three points by at least three first to third support members; and a control step of controlling the first to third support members with a control unit based on the shadow image of the peripheral edge so that the parallel light and the surface of the object to be measured are parallel along the projection direction, wherein the first to third support members are equipped with first to third movement mechanisms that move the first to third support positions of the object to be measured in the vertical direction, and the control step controls the first to third movement mechanisms individually.

[0024] Such a contour shape measurement method supports the measurement object from below with at least three points by at least the first to third support members, and individually controls the first to third moving mechanisms of the first to third support members that move the first to third support positions of the measurement object in the vertical direction. Therefore, there is no need to reinstall the light projection unit and the imaging unit, and the posture of the measurement object can be adjusted with two degrees of freedom, so that the posture of the measurement object can be adjusted more appropriately.

Advantages of the Invention

[0025] The contour shape measurement device and the contour shape measurement method according to the present invention can more appropriately adjust the posture of the measurement object.

Brief Description of the Drawings

[0026] [Figure 1] It is a block diagram showing the electrical configuration of the contour shape measurement device in the embodiment. [Figure 2] It is a schematic plan view of the contour shape measurement device. [Figure 3] It is a schematic side view of the contour shape measurement device as viewed from the A direction shown in FIG. 2. [Figure 4] It is a schematic side view of the contour shape measurement device as viewed from the B direction shown in FIG. 2. [Figure 5] It is a diagram for explaining the support member. [Figure 6] As an example, it is a diagram for explaining a plurality of parameters in the contour shape. [Figure 7] It is a diagram for explaining the calibration of the support member in the contour shape measurement device. [Figure 8] It is a flowchart showing the operation of the contour shape measurement device regarding calibration. [Figure 9] It is a flowchart showing the operation of the contour shape measurement device regarding the calibration of the support member shown in FIG. 8. [Figure 10] It is a flowchart showing the operation of the contour shape measurement device regarding the calibration of the support member in the modified form.

Embodiments for Carrying Out the Invention

[0027] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In each figure, components denoted by the same reference numerals are identified as identical components, and their descriptions are omitted where appropriate. In this specification, general reference numerals are used without subscripts, while individual components are indicated by subscripts.

[0028] The contour shape measuring device in this embodiment projects parallel light onto the peripheral edge of a disc-shaped object to be measured from a tangential direction of the outer circumference, captures the shadow of the peripheral edge created by the parallel light, and measures the contour shape of the peripheral edge based on the captured shadow image of the peripheral edge. This contour shape measuring device comprises at least three first to third support members for supporting the object to be measured from below at at least three points, and a control unit that controls the first to third support members based on the shadow image of the peripheral edge so that the parallel light and the surface of the object to be measured are parallel along the projection direction. The first to third support members are equipped with first to third movement mechanisms that move the first to third support positions of the object to be measured in the vertical direction, and the control unit controls the first to third movement mechanisms individually. The contour shape measuring device and the contour shape measuring method implemented therein will be described in more detail below.

[0029] Figure 1 is a block diagram showing the electrical configuration of the contour shape measuring device in an embodiment. Figure 2 is a schematic plan view of the contour shape measuring device. Figure 3 is a schematic side view of the contour shape measuring device as seen from direction A shown in Figure 2. Figure 4 is a schematic side view of the contour shape measuring device as seen from direction B shown in Figure 2. Figure 5 is a diagram illustrating the support member. Figure 5A is an overall view, and Figure 5B is a diagram illustrating the support claw member.

[0030] The contour shape measuring device 1000 in the embodiment includes, for example, a light-emitting unit 1, an imaging unit 2, an optical system holding unit 3, first to third support members 4-1 to 4-3, a control processing unit 5, an input unit 6, an output unit 7, an interface unit (IF unit) 8, and a storage unit 9, as shown in Figures 1 to 5.

[0031] The light-emitting unit 1 is connected to the control processing unit 5 and, in accordance with the control processing unit 5, projects parallel light onto the peripheral edge of a disc-shaped object to be measured WK from the tangential direction (light-emitting direction) DR of the outer circumference. The object to be measured WK can be any disc shape, such as a wafer used in semiconductor manufacturing (e.g., a silicon wafer) or an aluminum or glass magnetic disk substrate used in hard disks. The light-emitting unit 1 includes, for example, a light source 11 connected to the control processing unit 5 that emits illumination light in accordance with the control processing unit 5, and an illumination optical system 12 that irradiates the object with the illumination light emitted by the light source 11 as parallel light. The light source 11 includes, for example, a white light-emitting diode (white LED) and a pinhole plate with pinholes of about 300 [μm] to 400 [μm], and is a point light source that emits white light from the white LED as illumination light through the pinholes. The illumination optical system 12 includes, for example, a collimator lens 121 that converts illumination light emitted from the light source 11 into parallel light, and first and second mask plates 122 and 123 of the same shape that form rectangular apertures. The illumination light emitted from the light source 11 is converted into parallel light by the collimator lens 121, and the parallel light is emitted as a spot-shaped parallel light that passes through the respective rectangular apertures of the first and second mask plates 122 and 123. When the object to be measured WK is placed, the parallel light is projected onto the periphery of the object to be measured WK. The first and second mask plates 122 and 123 block light outside the imaging range of the imaging unit 2. In this example, there are two mask plates, but there may be one, three or more, or the mask plates may be omitted.

[0032] The imaging unit 2 is connected to the control processing unit 5 and, in accordance with the control processing unit 5, is a device that captures the peripheral shadow (image) of the measurement target WK generated by the parallel light. The imaging unit 2 comprises, for example, a light-receiving optical system 21 and a two-dimensional image sensor 22. The light-receiving optical system 21 is a telecentric lens comprising a first lens 211, an aperture 212, and a second lens 213, and forms an image (shadow) of the peripheral area of ​​the measurement target WK generated by the parallel light on the two-dimensional image sensor. The two-dimensional image sensor 22 is connected to the control processing unit 5 and comprises, for example, a CCD type or CMOS type two-dimensional image sensor, and, in accordance with the control processing unit 5, captures the image (shadow) of the peripheral area of ​​the measurement target WK formed by the light-receiving optical system 21 and outputs the data (RAW data) generated by the imaging to the control processing unit 5.

[0033] The optical system holding unit 3 holds the light-emitting unit 1 and the imaging unit 2 in a fixed positional relationship and is connected to the control processing unit 5. It is a device that adjusts the tilt of the optical axis AX (tilt of the light emission direction DR) in the light-emitting unit 1 and the imaging unit 2 according to the control of the control processing unit 5.

[0034] The inclination of the optical axis AX (inclination of the projection direction DR) is the inclination of the optical axis AX with respect to the surface (front or back surface) of the object WK to be measured when the peripheral edge of the object WK to be measured is located between the light-emitting unit 1 and the imaging unit 2, and is uniquely expressed by the angle between the surface (front or back surface) of the object WK to be measured and the optical axis AX (inclination of the projection direction DR). When the parallel light from the light-emitting unit 1 and the surface of the object WK to be measured are parallel along the projection direction DR, the inclination of the optical axis AX (inclination of the projection direction) is 0 degrees.

[0035] The optical system holding unit 3 includes, for example, a holding member 31, a support shaft 32, a shaft support member 33, a base member 34, and a tilt adjustment mechanism (first tilt adjustment mechanism) 35.

[0036] The holding member 31 is a member that holds the light-emitting unit 1 and the imaging unit 2. The holding member 31 is, for example, a metal plate (rigid body) extending in one direction, and is bent at approximately 90 degrees to form a rectangular holding plate portion 311 and a rectangular vertical plate portion 312, thereby exhibiting a roughly L-shaped cross-section. The light source 11, collimator lens 121, first mask plate 122, second mask plate 123, first lens 211, aperture 212, second lens 213, and two-dimensional image sensor 22 are fixedly arranged in order in the holding plate portion 311, with their optical axes AX aligned with each other. Therefore, if they are ideally arranged as designed, the optical axis AX and the light emission direction DR will coincide. The second mask plate 123 and the first lens 211 are arranged with an appropriate gap between them so that the peripheral portion of the measurement target WK can be positioned. The vertical plate portion 312 has an opening formed at approximately the center (the intersection of two diagonals) for inserting the support shaft 32.

[0037] The shaft support member 33 and the base member 34 are each plate-shaped members, and the shaft support member 33 is fixedly disposed on the base member 34 so as to stand upright. The support shaft 32 is a cylindrical member and protrudes from the shaft support member 33 at a position higher than the center position in the height direction (up and down direction) (upper position), and is inserted through the opening of the upright plate portion 312. As a result, the holding member 31 is pivotally supported by the support shaft 32 which is perpendicular to the light projection direction DR, and is rotatable about the support shaft 32.

[0038] As shown in Figures 2 to 4, when the XYZ Cartesian coordinate system is set up, if it is ideally arranged as designed, the projection direction DR (optical axis AX) is in the X-axis direction (the left and right directions in each plane of Figures 2 to 4), and the height direction is in the Z-axis direction (the up and down directions in each plane of Figures 3 and 4). The Y-axis direction is in the direction perpendicular to the projection direction DR (optical axis AX) and the height direction (the up and down direction in Figure 2). When the contour shape measuring device 1000 is ideally assembled as designed, and the periphery of the object to be measured WK is ideally positioned between the second mask plate 123 and the first lens 211, the surface of the object to be measured WK and the XY plane become parallel.

[0039] The tilt adjustment mechanism 35 is connected to the control processing unit 5 and, in accordance with the control processing unit 5, rotates the holding member 31 around the support shaft 32 to adjust the tilt of the light projection direction DR (tilt of the optical axis AX). The tilt adjustment mechanism 35 comprises, for example, a columnar rod member 351 erected on the base member 34, a servo motor 352 disposed at the tip of the rod member 351, a worm 353 provided on the rotation axis of the servo motor 352, and a worm wheel 354 fixedly disposed on the vertical plate portion 312 of the holding member 31. The worm 353 and the worm wheel 354 constitute a worm gear with gears meshing with each other. The servo motor 352 is connected to the control processing unit 5 and rotates in accordance with the control processing unit 5, thereby driving the worm gear, which in turn causes the holding member 31, pivotally supported on the support shaft 32, to rotate around the support shaft 32. This changes the tilt of the light projection direction DR (the tilt of the optical axis AX).

[0040] The first to third support members 4-1 to 4-3 are members for supporting the object to be measured WK from below at three points. The first to third support members 4-1 to 4-3 are arranged such that the first to third support positions that support the object to be measured WK are located at the vertices of a triangle, with the first and second support members 4-1 and 4-2 positioned relatively close to the parallel light, and the third support member 4-3 positioned relatively far from the parallel light. In this embodiment, in order to suppress the deflection of the object to be measured WK, the triangle is an isosceles triangle in which the length of the first line segment connecting the first support position and the second support position is shorter than the length of the second line segment connecting the first support position and the third support position (the length of the third line segment connecting the second support position and the third support position, (length of the second line segment) = (length of the third line segment)), and the first line segment is the base.

[0041] Since the first to third support members 4-1 to 4-3 have the same structure, the following description will mainly focus on the first support member 4-1. The symbols for the configurations of the second and third support members 4-2 and 4-3 will be indicated in parentheses after the symbols for the configuration of the first support member 4-1 corresponding to the configurations of the second and third support members 4-2 and 4-3. In exchange for this, the description of the second and third support members 4-2 and 4-3 will be omitted.

[0042] The first support member 4-1 (4-2, 4-3) includes, for example, as shown in Figure 5, a first movement mechanism 41-1 (41-2, 41-3) that moves the first support position of the object to be measured WK in the vertical direction (Z direction), and a first support claw member 42-1 (42-2, 42-3) having an inclined first support surface TF-1 (TF-2, TF-3) that makes point contact with the peripheral edge of the object to be measured WK. The first movement mechanism 41-1 (41-2, 41-3) is connected to the first support claw member 42-1 (42-2, 42-3). The first movement mechanism 41-1 (41-2, 41-3) is connected to the control processing unit 5, and moves the first support claw member 42-1 (42-2, 42-3) in the vertical direction according to the control of the control processing unit 5. As a result, the first support position, which supports the object to be measured WK by point contact with the first support surface TF-1 (TF-2, TF-3) of the first support claw member 42-1 (42-2, 42-3), moves in the vertical direction. The first moving mechanism 41-1 (41-2, 41-3) includes, for example, an electric cylinder (electromagnetic solenoid, electromagnetic actuator) erected on the base member 34. The electric cylinder includes, for example, an electric motor connected to the control processing unit 5 and rotating according to the control of the control processing unit 5, a columnar piston rod, and a conversion mechanism that converts the rotational motion of the electric motor into linear motion of the piston rod. The first support claw member 42-1 (42-2, 42-3) is a columnar member, such as a rectangular or cylindrical column, and has a first support surface TF-1 (TF-2, TF-3) with an inclined tapered surface, which is cut at one end at an angle. As an example of the first moving mechanism 41-1 (41-2, 41-3), a first support claw member 42-1 (42-2, 42-3) is fixedly disposed at the other end of the tip of the piston rod in the electric cylinder and connected (linked) to it.

[0043] As shown in Figure 2, the first to third support members 4-1 to 4-3 are arranged such that the first to third support positions are located at the vertices of a triangle (an isosceles triangle in this embodiment), and the first to third support surfaces TF-1 to TF-3 face inward from the triangle (more specifically, the center of the circumscribed circle of the triangle). The object to be measured WK is supported from below by the first to third support surfaces TF-1 to TF-3 of the first to third support claw members 42-1 to 42-3 so as to be in point contact around its periphery, and is positioned between the light-emitting unit 1 and the imaging unit 2 so as to project the parallel light onto the periphery of the object to be measured WK. Therefore, the holding plate portion 311 of the holding member 31 has openings formed at positions corresponding to the arrangement positions of the first and second support members 4-1 and 4-2, through which the first and second moving mechanisms 41-1 and 41-2 are inserted, respectively. Furthermore, the openings through which the first and second moving mechanisms 41-1 and 41-2 are inserted may also be openings for the first and second support claw members 42-1 and 42-2 to extend and retract, respectively.

[0044] Furthermore, there may be four or more support members 4 in order to support the object to be measured WK from below at four or more points.

[0045] The input unit 6 is connected to the control processing unit 5 and is a device that inputs various commands to the contour shape measuring device 1000, such as commands to instruct the start of calibration and commands to instruct the start of measurement, as well as various data necessary for operating the contour shape measuring device 1000, such as the name of the WK to be measured. For example, it may be a plurality of input switches assigned to predetermined functions, a keyboard, a mouse, etc. The output unit 7 is connected to the control processing unit 5 and is a device that outputs commands, data, and measurement results input from the input unit 6 according to the control of the control processing unit 5. For example, it may be a display device such as a CRT display, LCD (liquid crystal display device), or organic EL display, or a printing device such as a printer.

[0046] The input unit 6 and output unit 7 may be configured as touch panels. In this configuration, the input unit 6 is a position input device that detects and inputs the operating position, such as a resistive or capacitive touchscreen, and the output unit 7 is a display device. In this touch panel, a position input device is provided on the display surface of the display device, and one or more candidate input contents that can be input to the display device are displayed. When the user touches the display position that displays the input content they want to input, the position input device detects that position, and the display content displayed at the detected position is input to the contour shape measuring device 1000 as the user's operation input. With such a touch panel, the user can easily understand the input operation intuitively, thus providing a contour shape measuring device 1000 that is easy for the user to handle.

[0047] The IF unit 8 is connected to the control processing unit 5 and, in accordance with the control of the control processing unit 5, is a circuit that inputs and outputs data to and from external devices, for example. Examples include an RS-232C serial communication interface circuit, an interface circuit using the Bluetooth® standard, and an interface circuit using the USB standard. Alternatively, the IF unit 8 may be a communication interface circuit that sends and receives communication signals to and from external devices, such as a data communication card or a communication interface circuit conforming to the IEEE 802.11 standard.

[0048] The memory unit 9 is electrically connected to the control processing unit 5 and is a circuit that stores various predetermined programs and various predetermined data in accordance with the control of the control processing unit 5.

[0049] The various predetermined programs mentioned above include, for example, a control processing program, which includes, for example, a control program, an image processing program, a first tilt control program, a second tilt program, and a contour shape processing program. The control program controls each part 11, 22, 6-9 of the contour shape measuring device 1000 according to the function of each part. The image processing program is a program that generates image data (shadow image data), which is data representing the shadow image of the peripheral part of the measurement target WK, by image processing the data (RAW data) output from the two-dimensional image sensor 22 of the imaging unit 2. The first tilt control program is a program that controls the tilt adjustment mechanism (first tilt adjustment mechanism) 35 so that the parallel light from the light projection unit 1 and the surface of the measurement target WK are parallel along the light projection direction DR. The second tilt control program is a program that individually controls the first to third movement mechanisms 41-1 to 41-3 (second tilt adjustment mechanisms) of the first to third support members 4-1 to 4-3 so that the parallel light from the light-emitting unit 1 and the surface of the object to be measured WK are parallel along the light-emitting direction DR. The contour shape processing program is a program that determines the contour shape of the peripheral part of the object to be measured WK based on the shadow image of the peripheral part. The various predetermined data include, for example, the name of the object to be measured WK, the reference value of a reference measurement target whose contour shape is known, and the measurement result, and other data necessary for executing each of these programs.

[0050] Such a storage unit 9 may include, for example, a non-volatile memory element such as ROM (Read Only Memory) or a rewritable non-volatile memory element such as EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 9 also includes RAM (Random Access Memory) which serves as the working memory of the control processing unit 5, storing data generated during the execution of the predetermined program. Furthermore, the storage unit 9 may be configured to include a hard disk drive or solid-state drive (SSD) with a relatively large storage capacity.

[0051] The control processing unit 5 is a circuit for measuring the contour shape of the peripheral portion of the object to be measured by controlling each part 11, 22, 6-9 of the contour shape measuring device 1000 according to the function of each part. The control processing unit 5 is configured, for example, with a CPU (Central Processing Unit) and its peripheral circuits. When the control processing program is executed, the control unit 5 is functionally configured with a control unit 51, an image processing unit 52, a first tilt control unit 53, a second tilt control unit 54, and a contour shape processing unit 55.

[0052] The control unit 51 controls each part 11, 22, 6-9 of the contour shape measuring device 1000 according to the function of each part, and is in charge of the overall control of the contour shape measuring device 1000.

[0053] The image processing unit 52 generates image data (shadow image data), which represents the shadow image of the peripheral area of ​​the measurement target WK, by processing the data (RAW data) output from the two-dimensional image sensor 22 of the imaging unit 2 using a known processing method.

[0054] The first tilt control unit 53 controls the tilt adjustment mechanism (first tilt adjustment mechanism) 35 so that the parallel light from the light-emitting unit 1 and the surface of the object to be measured WK are parallel along the light emission direction DR. For example, when the object to be measured WK is supported from below by first to third support members 4-1 to 4-3 and placed between the light-emitting unit 1 and the imaging unit 2, the contour shape measuring device 1000 further includes two first and second distance meters (e.g., laser distance meters) that measure the distances from above (or below) to the object to be measured WK at two points spaced apart along the optical axis AX in the light-emitting unit 1 and the imaging unit 2. The first tilt control unit 53 determines the tilt of the optical axis AX with respect to the surface of the object to be measured WK (tilt of the light emission direction DR) based on the difference (distance difference) of the distances measured by the first and second distance meters, and controls the tilt adjustment mechanism 35 so that the determined tilt of the optical axis AX becomes 0, or the distance difference becomes 0.

[0055] The second tilt control unit 54 individually controls the first to third moving mechanisms 41-1 to 41-3 (second tilt adjustment mechanisms) of the first to third support members 4-1 to 4-3 so that the parallel light from the light-emitting unit 1 and the surface of the object to be measured WK are parallel along the light-emitting direction DR.

[0056] In this embodiment, the orientation of the holding member 31 is adjusted by controlling the tilt adjustment mechanism 35 so that the parallel light from the light-emitting unit 1 and the surface of the object to be measured WK are parallel along the light emission direction DR (first calibration process). The orientation of the object to be measured WK is adjusted by individually controlling the first to third moving mechanisms 41-1 to 41-3 of the first to third support members 4-1 to 4-3 so that the parallel light from the light-emitting unit 1 and the surface of the object to be measured WK are parallel along the light emission direction DR (second calibration process). In this second calibration process, as described later, the reference object to be measured WK0 is used as the object to be measured WK. Thus, in this embodiment, the geometric relationship between the light emission direction DR and the surface of the object to be measured WK is adjusted in two stages.

[0057] More specifically, if the contour shape of the measurement result deviates from the known contour shape (because the contour shape of the measurement result contains an error), the second tilt control unit 54 individually controls the first to third moving mechanisms 41-1 to 41-3 of the first to third support members 4-1 to 4-3 so that, when the contour shape is measured using a reference measurement target WK whose contour shape is known, the difference between the known contour shape and the contour shape of the measurement result is minimized. More specifically, the contour shape of the peripheral portion is divided into multiple parts, and each part is associated with one or more predetermined parameters that are set (defined) in advance to represent the contour shape of that part, and the second tilt control unit 54 individually controls the first to third moving mechanisms 41-1 to 41-3 of the first to third support members 4-1 to 4-3 so as to minimize the difference between the reference value of one of the multiple parameters in the known contour shape and the measured value of the one parameter in the contour shape of the measurement result.

[0058] In the individual controls described above, the second tilt control unit 54 sequentially executes the following: a first movement control that controls one of the first and second movement mechanisms 41-1 and 41-2 of the first and second support members 4-1 and 4-2, which are positioned relatively close to the parallel light (for example, the first movement mechanism 41-1), so as to minimize the difference; a second movement control that controls the other of the first and second movement mechanisms 41-1 and 41-2 (in this example, the second movement mechanism 41-2), so as to minimize the difference; and a third movement control that controls the third movement mechanism 41-3 of the third support member 4-3, which is positioned relatively far from the parallel light, so as to minimize the difference. After executing the third movement control, the unit returns to the first movement control and sequentially executes the first to third movement controls. Here, while the first to third movement controls are being executed sequentially, the second tilt control unit 54 determines whether the difference is less than or equal to an allowable value after each movement control of the first to third movement controls and before executing the next movement control. If the result of the determination is that the difference is less than or equal to an allowable value, the unit terminates without executing the next movement control. On the other hand, if the result of the determination is that the difference is not less than or equal to an allowable value, the unit executes the next movement control. The allowable value is set appropriately in advance from, for example, a plurality of samples.

[0059] The second tilt control unit 54 will be described in more detail using Figures 6 and 7. Figure 6 is a diagram illustrating, as an example, several parameters in the contour shape. Figure 7 is a diagram illustrating the calibration of the support member in the contour shape measuring device. The horizontal axis of Figure 7 represents the first support position [μm], and its vertical axis represents the parameter A1 [μm].

[0060] Figure 6 shows the contour shape OL of the object to be measured WK as a relatively thick solid line. In the example shown in Figure 6, the peripheral contour shape OL is divided into the bevel portion SB of the surface (one main surface), the bevel portion RB of the back surface (the other main surface opposite the one main surface), and the tip portion FE. Three parameters are associated with the surface bevel portion SB and the back bevel portion RB, respectively: inclination angle θ1, θ2, bevel length A1, A2, and bevel height B1, B2. One parameter, the tip portion FE, is associated with the position of the tip c (tip position) C. The inclination angle θ1 of the surface bevel portion SB is the angle made between the surface of the surface bevel portion SB and the surface of the object to be measured WK, and is expressed as that angle. The bevel length A1 of the surface bevel SB is the distance between the starting point a1 of the surface bevel SB and the intersection line e1 between the surface of the surface bevel SB and the tangent plane of the tip c, and is expressed as that length. The starting point a1 of the surface bevel SB is the position where the surface of the object WK to be measured begins to tilt. The surface bevel SB extends from the starting point a1 to the position where the surface of the surface bevel SB deviates from the tilt angle θ1 of the surface bevel SB. The bevel height B1 of the surface bevel SB is the distance between the surface of the object WK to be measured and the intersection line e1 between the surface of the surface bevel SB and the tangent plane of the tip c, and is expressed as that length. Similarly, the tilt angle θ2 of the back surface bevel RB is the angle between the surface of the back surface bevel RB and the back surface of the object WK to be measured, and is expressed as that angle. The starting point a2 of the back surface bevel RB is the position where the back surface of the object WK to be measured begins to tilt. The bevel length A2 of the back bevel RB is the distance between the starting point a2 of the back bevel RB and the intersection line e2 between the surface of the back bevel RB and the tangent plane of the tip c, and is expressed as that length. The bevel height B2 of the back bevel RB is the distance between the surface of the object WK being measured and the intersection line e2 between the surface of the back bevel RB and the tangent plane of the tip c, and is expressed as that length. The back bevel RB extends from the starting point a2 of the back bevel RB to the position where the surface of the back bevel RB deviates from the inclination angle θ2 of the back bevel RB. The tip FE is located between the surface bevel SB and the back bevel RB.

[0061] All or more of these seven parameters A1, A2, B1, B2, θ1, θ2, and C may be used, but since these seven parameters A1, A2, B1, B2, θ1, θ2, and C are interdependent and their values ​​are interconnected, in this embodiment, one of the seven parameters A1, A2, B1, B2, θ1, θ2, and C, for example, parameter A1 (bevel length A1 of the surface bevel portion SB), is used. Of course, any one of the other parameters A2, B1, B2, θ1, θ2, and C may be used. Note that the parameters are not limited to A1, A2, B1, B2, θ1, θ2, and C, and other parameters may be used as long as they characterize the contour shape of the peripheral portion of the object WK to be measured.

[0062] In adjusting the orientation of the object to be measured WK by the second tilt control unit 54, first, a reference object to be measured WK0 (not shown) is selected, and parameter A1 is measured as the reference value of parameter A1; y0. For example, one appropriate object from among several objects to be measured WK is selected as the reference object to be measured WK0. If the object to be measured WK is an industrial product, there is little difference between products, so the reference object to be measured WK0f may be selected from among several objects to be measured WK. Then, for example, parameter A1 of the reference object to be measured WK0 is measured by the user using a caliper or a 3D shape measuring machine, and the measured parameter A1; y0 is input to the contour shape measuring device 1000 via the input unit 6 and stored in the storage unit 9 as the reference value of parameter A1; y0. Alternatively, for example, the parameter A1;y0 of the reference measurement target WK0 is determined using another pre-adjusted contour shape measuring device 1000, and stored in the storage unit 9 as the reference value;y0 of parameter A1. The mounting device (not shown in the figure) is adjusted so that when the measurement target WK and the reference measurement target WK0 are placed on the first to third support members 4-1 to 4-3, the respective center positions of the measurement target WK and the reference measurement target WK0 coincide with the center positions of the first to third support members 4-1 to 4-3 (the center positions of the circumscribed circles of the isosceles triangles).

[0063] First, the reference measurement target WK0 is placed on the first to third support members 4-1 to 4-3 using the mounting device shown in the figure (not shown). As mentioned above, since there is almost no difference between the products, the measurement target WK may be used as a substitute for the reference measurement target WK0.

[0064] Next, the second tilt control unit 54 performs first movement control to control one of the first and second movement mechanisms 41-1 and 41-2, in this case the first movement mechanism 41-1, so as to minimize the difference. More specifically, the second tilt control unit 54 moves the first movement mechanism vertically along a preset scanning range at a preset scanning interval, and each time it moves at the scanning interval, the contour shape processing unit 55 determines the parameter A1 at its first support position, and stores this determined measured parameter A1 in the storage unit 9 in association with the first support position (or number of movements). Before the start of scanning, the first movement mechanism 41-1 is set so that its first support position is a preset default position (initial position). Next, once scanning is complete, the second tilt control unit 54 determines the curve (or straight line); y=f(x) that best fits each measurement result when plotting each measurement result at each coordinate represented by each first support position and each parameter A1 in a coordinate space where the first support position and parameter A1 are the x and y axes, respectively. This determines the relationship; f between the first support position; x and parameter A1; y. For example, in the example shown in Figure 7, the scanning range is set from -10 [μm] to +40 [μm] relative to the default (initial position); 0, and the scanning interval is set to 5 [μm]. Each parameter A1; y is measured at each first support position; x of -10 [μm], -5 [μm], 0 [μm], +5 [μm], +10 [μm], +15 [μm], +20 [μm], +25 [μm], +30 [μm], +35 [μm], and +40 [μm]. Subsequently, the second tilt control unit 54, for example as shown in Figure 7, substitutes the reference value of parameter A1; y0 stored in the memory unit 9 for the parameter A1; y of the obtained curve (or straight line); y = f(x), and determines the first support position; x0 in this case (y0 = f(x0)). Next, the second tilt control unit 54 controls the first movement mechanism 41-1 so that it reaches the first support position x0 determined above. This executes a first movement control that controls the first movement mechanism 41-1 so that the difference is minimized.

[0065] Next, the second tilt control unit 54 obtains the parameter A1;y0r at the first support position;x0 using the contour shape processing unit 55 and stores it in the storage unit 9. Subsequently, the second tilt control unit 54 determines whether the difference between the reference value;y0 of parameter A1 and the measured value;y0r of parameter A1 from the measurement results is less than or equal to an allowable value. If the result of this determination is that the difference is less than or equal to an allowable value, the second tilt control unit 54 terminates without executing the next second movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value, the second tilt control unit 54 executes the next second movement control.

[0066] In the second movement control that controls the second movement mechanism 41-2 in this example so as to minimize the aforementioned difference, the second tilt control unit 54 operates on the second movement mechanism 41-2 in the same way as the first movement control, instead of the first movement mechanism 41-1. That is, the second tilt control unit 54 scans the second support position within the scanning range and scanning interval to obtain each measurement result of each parameter A1 at each second support position and finds a curve (or straight line) that best fits the result. The second movement mechanism 41-2 is then controlled to obtain the second support position by substituting the reference value y0 of parameter A1 stored in the storage unit 9 into the obtained curve (or straight line).

[0067] Next, the second tilt control unit 54 uses the contour shape processing unit 55 to determine the parameter A1 at this second support position, and determines whether the difference between the reference value y0 of parameter A1 and the measured value of parameter A1 in the measurement result is less than or equal to an allowable value. If the result of this determination is that the difference is less than or equal to an allowable value, the second tilt control unit 54 terminates without executing the next third movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value, the second tilt control unit 54 executes the next third movement control.

[0068] In the third movement control, which controls the third movement mechanism 41-3 to minimize the aforementioned difference, the second tilt control unit 54 operates on the third movement mechanism 41-3 in the same way as the first movement control, instead of the first movement mechanism 41-1. That is, the second tilt control unit 54 scans the third support position within the scanning range and scanning interval to obtain each parameter A1 at each third support position and finds the curve (or straight line) that best fits each measurement result. The third movement mechanism 41-3 is then controlled to become the third support position obtained by substituting the reference value y0 of parameter A1 stored in the storage unit 9 into the obtained curve (or straight line).

[0069] Next, the second tilt control unit 54 uses the contour shape processing unit 55 to determine the parameter A1 at the third support position and determines whether the difference between the reference value y0 of parameter A1 and the measured value of parameter A1 in the measurement results is less than or equal to an allowable value. If the result of this determination is that the difference is less than or equal to an allowable value, the second tilt control unit 54 terminates without executing the next first movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value, the second tilt control unit 54 executes the next first movement control.

[0070] In this manner, the first to third movement processes are executed sequentially after each movement control until the difference between the reference value of parameter A1 (y0) and the measured value of parameter A1 falls below the allowable value.

[0071] Furthermore, since the difference may not fall below an acceptable value even if the operations are performed sequentially as described above, the contour shape measuring device 1000 may be configured such that the number of times the first to third movement controls are performed sequentially (number of cycles) is set in advance to, for example, 3 or 5 times, and if the difference is not below an acceptable value even after the number of cycles is completed, the first to third movement controls are terminated and an error message (for example, "Calibration not possible. Please contact the manufacturer for repair.") is output to the output unit 7.

[0072] When adjusting using multiple parameters, proceed as follows: Determine the support position x0 for each parameter using the method described above, calculate the average value of the multiple support positions x0 obtained, and control the movement mechanism so that it matches the calculated average value. The condition for completing the adjustment is that for all parameters, the difference between the reference value and the measured value is less than or equal to the tolerance value set for each parameter.

[0073] Returning to Figures 1 to 5, the contour shape processing unit 55 determines the contour shape of the peripheral area based on the shadow image of the peripheral area of ​​the measurement target WK. The contour shape processing unit 55 then determines the parameters A1, A2, B1, B2, θ1, θ2, and C from these generated lines and curves and stores them in the storage unit 9.

[0074] The control processing unit 5, input unit 6, output unit 7, IF unit 8, and storage unit 9 in such a contour shape measuring device 1000 can be configured by a computer, such as a desktop or notebook computer.

[0075] Next, the operation of this embodiment will be described. Figure 8 is a flowchart showing the operation of the contour shape measuring device in relation to calibration. Figure 9 is a flowchart showing the operation of the contour shape measuring device in relation to the calibration of the support member shown in Figure 8.

[0076] When the contour shape measuring device 1000 with this configuration is powered on, it performs the initialization of each necessary part and starts operating. The control processing unit 5 is functionally configured with a control unit 51, an image processing unit 52, a first tilt control unit 53, a second tilt control unit 54, and a contour shape processing unit 55 through the execution of its control processing program.

[0077] When the user (operator) initiates calibration via the input unit 6, in Figure 8, first, the contour shape measuring device 1000 controls the tilt adjustment mechanism 35 by the first tilt control unit 53 of the control processing unit 5, thereby adjusting the posture of the holding member 31 so that the parallel light from the light projection unit 1 and the surface of the object to be measured WK are parallel along the light projection direction DR (S1, first calibration process).

[0078] Then, the contour shape measuring device 1000 controls the first to third moving mechanisms 41-1 to 41-3 of the first to third support members 4-1 to 4-3 by the second tilt control unit 54 of the control processing unit 5, thereby adjusting the orientation of the measurement target WK (reference measurement target WK0) so that the parallel light from the light projection unit 1 and the surface of the measurement target WK are parallel along the light projection direction DR (S2, second calibration process), and the process ends.

[0079] In this second calibration process S2, as shown in Figure 9, first, the contour shape measuring device 1000, under the control processing unit 5, places the reference measurement target WK0 on the first to third support members 4-1 to 4-3 using the mounting device (not shown) (S11).

[0080] Next, the contour shape measuring device 1000 performs a first movement control using the second tilt control unit 54 to calibrate the first support member 4-1 (S12).

[0081] Next, the contour shape measuring device 1000 determines whether the difference between the reference value of parameter A1 and the measured value of parameter A1 at the first support position after executing the first movement control in process S12 is less than or equal to an allowable value (S13). If the result of this determination is that the difference is less than or equal to an allowable value (Yes), the second tilt control unit 54 executes process S18 without executing the next second movement control. On the other hand, if the result of the determination is that the difference is not less than or equal to an allowable value (No), the second tilt control unit 54 executes process S14 in order to execute the next second movement control.

[0082] In process S14, the contour shape measuring device 1000 performs a second movement control by the second tilt control unit 54 in order to calibrate the second support member 4-2.

[0083] Next, the contour shape measuring device 1000 determines whether the difference between the reference value of parameter A1 and the measured value of parameter A1 at the second support position after executing the second movement control in process S14 is less than or equal to an allowable value (S15). If the result of this determination is that the difference is less than or equal to an allowable value (Yes), the second tilt control unit 54 executes process S18 without executing the next third movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value (No), the second tilt control unit 54 executes process S16 in order to execute the next third movement control.

[0084] In process S16, the contour shape measuring device 1000 performs a third movement control by the second tilt control unit 54 in order to calibrate the third support member 4-3.

[0085] Next, the contour shape measuring device 1000 determines whether the difference between the reference value of parameter A1 and the measured value of parameter A1 at the third support position after executing the third movement control in process S16 is less than or equal to an allowable value (S17). If the result of this determination is that the difference is less than or equal to an allowable value (Yes), the second tilt control unit 54 executes process S18 without executing the next first movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value (No), the second tilt control unit 54 returns to process S12 in order to execute the next first movement control.

[0086] In the process S18, the contour shape measuring device 1000 terminates the process when the second tilt control unit 54 notifies the completion of the calibration. In this notification, a message indicating the completion of calibration, such as "Calibration completed," is output to the output unit 7.

[0087] Furthermore, the above calibration does not need to be performed after every measurement; it can be performed at appropriate intervals (regularly or irregularly) as needed. For example, if the object to be measured WK is supported by the support member 4, and the support claw member 42 is made of a softer material than the object to be measured WK in order to avoid damaging it, the support surface TF of the support claw member 42 will wear down after multiple measurements, causing the support position to shift. For this reason, the above calibration is performed when a predetermined number of measurements has been reached, either by the user's instruction to start calibration or by the determination of the number of measurements by the contour shape measuring device 1000.

[0088] As described above, the contour shape measuring device 1000 and the contour shape measuring method implemented therein in the embodiment support the object to be measured WK from below at at least three points with at least first to third support members 4-1 to 4-3, and individually control the first to third moving mechanisms 41-1 to 41-3 of the first to third support members 4-1 to 4-3 that move the first to third support positions of the object to be measured WK in the vertical direction. Therefore, there is no need to reattach the light-emitting unit 1 and the imaging unit 2, and the posture of the object to be measured WK can be adjusted with two degrees of freedom, so the posture of the object to be measured WK can be adjusted more appropriately.

[0089] The above-described contour shape measuring device 1000 and contour shape measuring method can be calibrated so that the first to third support positions of the first to third support members 4-1 to 4-3 are parallel to the direction of light projection, using a reference measurement target WK0 whose contour shape is known.

[0090] The above-described contour shape measuring device 1000 and contour shape measuring method are calibrated using one of several parameters, thus simplifying the calibration process.

[0091] The above-described contour shape measuring device 1000 and contour shape measuring method perform the first to third movement processes cyclically and sequentially until the difference falls below an acceptable value, thereby enabling more reliable calibration.

[0092] When the disc-shaped object WK to be measured is relatively thin, a long distance between support positions may cause the object WK to flex. If the object flexes at the periphery where the parallel light is projected, the measurement accuracy of the contour shape of the periphery will deteriorate. For this reason, it is preferable that the distance between the first and second support positions that support the periphery where the parallel light is projected is short. When the first to third support members 4-1 to 4-3 are arranged such that the first to third support positions are located at the vertices of an equilateral triangle, the distances between each support position at the first to third support positions become equal. However, the contour shape measuring device 1000 and contour shape measuring method arrange the first to third support members 4-1 to 4-3 so that they are located at the vertices of an isosceles triangle with the line segment connecting the first support position and the second support position as the base. Therefore, the distance between the support positions of the first and second support positions (12th distance) can be made shorter than the distance between the support positions of the first and third support positions (13th distance) and the distance between the support positions of the second and third support positions (23rd distance). This reduces the risk of deflection and reduces the deterioration of measurement accuracy.

[0093] In the above-described contour shape measuring device 1000 and contour shape measuring method, the first to third support members 4-1 to 4-3 are arranged such that the inclined first to third support surfaces face inward into the triangle. Therefore, when the first to third support members 4-1 to 4-3 are individually controlled in the vertical direction, horizontal movement (movement in the XY plane) is inhibited. This allows the object to be measured WK to be supported more reliably by the first to third support members 4-1 to 4-3, and reduces the risk of the object to be measured WK deviating from the support of the first to third support members 4-1 to 4-3.

[0094] In the above-described embodiment, the second calibration process was performed by the first to third movement control, but it may also be performed by the first and second movement control (a modified form of the second calibration process). More specifically, the second tilt control unit 54 alternately performs a first movement control to control one of the first and second movement mechanisms 41-1 and 41-2 in the first and second support members 4-1 and 4-2 (for example, the first movement mechanism 41-1), and a second movement control to control the other of the first and second movement mechanisms 41-1 and 41-2 (in this example, the second movement mechanism 41-2), until the difference between the reference value of one of the multiple parameters in the known contour shape and the measured value of that one parameter in the contour shape of the measurement result is less than or equal to an allowable value. Calibration can often be performed by adjusting the first and second support positions of the first and second support members 4-1 and 4-2, which are positioned relatively close to the parallel light. In the aforementioned deformed form, the contour shape measuring device 1000 performs the first and second movement processes alternately until the difference becomes less than or equal to an acceptable value, thus enabling calibration in a shorter time.

[0095] Figure 10 is a flowchart showing the operation of the contour shape measuring device for calibration of the support member in a deformed form. In the second calibration process of the contour shape measuring device 1000 in this deformed form, the following operation shown in Figure 10 is performed instead of the operation shown in Figure 9.

[0096] In Figure 10, first, the contour shape measuring device 1000 places the reference measurement target WK0 on the first to third support members 4-1 to 4-3, similar to the process S11 described above (S21), and then performs the first movement control to calibrate the first support member 4-1, similar to the process S12 described above (S22).

[0097] Next, the contour shape measuring device 1000 determines whether the difference between the reference value of parameter A1 and the measured value of parameter A1 at the first support position after executing the first movement control in process S22 is less than or equal to an allowable value (S23). If the result of this determination is that the difference is less than or equal to an allowable value (Yes), the second tilt control unit 54 executes process S26 without executing the next second movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value (No), the second tilt control unit 54 executes process S24 in order to execute the next second movement control.

[0098] In process S24, the contour shape measuring device 1000 performs a second movement control in order to calibrate the second support member 4-2, similar to process S14 described above.

[0099] Next, the contour shape measuring device 1000 determines whether the difference between the reference value of parameter A1 and the measured value of parameter A1 at the second support position after executing the second movement control in process S24 is less than or equal to an allowable value (S25). If the result of this determination is that the difference is less than or equal to an allowable value (Yes), the second tilt control unit 54 executes process S26 without executing the next first movement control. On the other hand, if the result of this determination is that the difference is not less than or equal to an allowable value (No), the second tilt control unit 54 returns to process S22 in order to execute the next first movement control.

[0100] In the process S26 described above, the contour shape measuring device 1000 notifies that the calibration is complete, similar to the process S18 described above, and terminates this process.

[0101] To illustrate the present invention, the embodiments have been adequately and fully described above with reference to the drawings. However, those skilled in the art should recognize that it is easy to modify and / or improve upon the embodiments described above. Therefore, unless such modifications or improvements implemented by those skilled in the art fall outside the scope of the claims, such modifications or improvements shall be considered to be included within the scope of the claims. [Explanation of Symbols]

[0102] 1000 Contour Shape Measuring Device 1. Light-emitting unit 2 Imaging Unit 3 Optical system holder 4-1~4-3 First to third support members 5 Control Processing Unit 9 Memory section 41-1~41-3 First to Third Movement Mechanism 42-1~42-3 First to third support claw members 51 Control Unit 52 Image Processing Unit 53 First tilt control unit 54 Second tilt control unit 55 Contour shaping processing unit

Claims

1. A contour shape measuring device that projects parallel light onto the peripheral edge of a disc-shaped object to be measured from the tangential direction of the outer circumference, captures the shadow of the peripheral edge caused by the parallel light, and measures the contour shape of the peripheral edge based on the captured shadow image of the peripheral edge, At least three first to third support members for supporting the object to be measured from below at at least three points, The system includes a control unit that controls the first to third support members based on the shadow image of the peripheral portion so that the parallel light and the surface of the object to be measured are parallel along the direction of light projection, The first to third support members are equipped with first to third movement mechanisms that move the first to third support positions of the object to be measured in the vertical direction. The control unit controls the first to third moving mechanisms individually. Contour shape measuring device.

2. The control unit individually controls the first to third moving mechanisms in such a way that, when measuring the contour shape of a reference measurement target whose contour shape is known, the difference between the known contour shape and the contour shape obtained from the measurement is minimized, in order to make them parallel. The contour shape measuring device according to claim 1.

3. The contour shape of the peripheral portion is divided into multiple parts, and one or more parameters are associated with each part. The control unit individually controls the first to third moving mechanisms based on the difference between each reference value of the one or more parameters in the known contour shape and each measured value of the one or more parameters in the contour shape of the measurement result. The contour shape measuring device according to claim 2.

4. The contour shape of the peripheral portion is divided into multiple parts, and one or more parameters are associated with each part. The control unit individually controls the first to third moving mechanisms so as to minimize the difference between a reference value of one of the multiple parameters in the known contour shape and the measured value of that one parameter in the contour shape of the measurement result. The contour shape measuring device according to claim 2.

5. The first to third support members are arranged such that the first to third support positions are located at the vertices of the triangle. The first and second support members are positioned relatively close to the parallel light, The third support member is positioned at a location relatively far from the parallel light, The control unit, Based on the difference, a first movement control is performed to control one of the first and second movement mechanisms; based on the difference, a second movement control is performed to control the other of the first and second movement mechanisms; and based on the difference, a third movement control is performed to control the third movement mechanism; after the execution of the third movement control, the process returns to the first movement control and the first to third movement controls are performed sequentially. While the first to third movement controls are being executed sequentially, after each of the first to third movement controls is executed, and before executing the next movement control, it is determined whether the value based on the difference is less than or equal to an allowable value. If the result of the determination is that the value based on the difference is less than or equal to an allowable value, the execution of the next movement control is terminated. On the other hand, if the result of the determination is that the value based on the difference is not less than or equal to an allowable value, the next movement control is executed. The contour shape measuring device according to claim 3.

6. The first to third support members are arranged such that the first to third support positions are located at the vertices of the triangle. The first and second support members are positioned relatively close to the parallel light, The third support member is positioned at a location relatively far from the parallel light, The control unit alternately executes a first movement control, which controls one of the first and second movement mechanisms, and a second movement control, which controls the other of the first and second movement mechanisms, so as to minimize the difference, until the value based on the difference becomes less than or equal to an allowable value. The contour shape measuring device according to claim 3.

7. The first to third support members are arranged such that the first to third support positions are located at the vertices of an isosceles triangle with the first support position as the base, and the length of the first line segment connecting the first support position and the second support position is shorter than the length of the second line segment connecting the first support position and the third support position. The first and second support members are positioned relatively close to the parallel light, The third support member is positioned at a location relatively far from the parallel light. A contour shape measuring device according to any one of claims 1 to 6.

8. The first to third support members further include first to third support claw members having inclined first to third support surfaces so as to make point contact with the peripheral edge of the object to be measured. The first to third support members are arranged such that the first to third support positions are located at the vertices of the triangle, and the first to third support surfaces face inward from the triangle. The first to third moving mechanisms are connected to the first to third support claw members and move the first to third support claw members in the vertical direction. A contour shape measuring device according to any one of claims 1 to 6.

9. A contour shape measurement method comprising projecting parallel light onto the peripheral edge of a disc-shaped object to be measured from a tangential direction of the outer circumference, imaging the shadow of the peripheral edge caused by the parallel light, and measuring the contour shape of the peripheral edge based on the image of the shadow of the peripheral edge captured, A support step in which the object to be measured is supported from below by at least three first to third support members at at least three points, The system includes a control step of controlling the first to third support members by the control unit based on the shadow image of the peripheral portion so that the parallel light and the surface of the object to be measured are parallel along the direction of light projection, The first to third support members are equipped with first to third movement mechanisms that move the first to third support positions of the object to be measured in the vertical direction. The control step involves individually controlling the first to third moving mechanisms. Contour shape measurement method.

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