Eccentricity measurement method and measurement system

Abstract

Provided are an eccentricity measurement method and a measurement system with which eccentricity of an object to be measured can be measured with high accuracy. The eccentricity measurement method includes: a step (S13) for acquiring optical surface measurement data by measuring an optical surface of an object to be measured by a probe (11); a step (S14) for calculating the optical axis center position of the object to be measured on the basis of the optical surface measurement data; a step (S15) for acquiring outer shape measurement data by measuring the outer shape of the object to be measured by the camera (21); a step (S16) for calculating the center position of the outer shape of the object to be measured on the basis of the outer shape measurement data; and a step (S17) for calculating eccentricity, which is the amount of deviation between the center position of the optical axis and the center position of the outer shape.

Description

Technical Field

[0001] The present disclosure relates to an eccentricity measuring method and a measuring system for measuring the eccentricity of an object to be measured. Background Art

[0002] Various lenses such as aspherical lenses and spherical lenses are used in the optical system of optical equipment such as cameras. If there is decentering in the lens used in the optical system, the optical performance of the entire optical system will be reduced. Therefore, in the past, there is a known decentering measurement method for measuring the decentering of a lens.

[0003] As such a method for measuring eccentricity, there is a known method for measuring the outer diameter eccentricity of a lens by bringing a probe into contact with the optical surface of a lens (inspected lens) as a measured object (e.g., Patent Document 1). In addition, there is also a known method for measuring the front-to-back eccentricity of a lens by measuring the positional relationship between the front and back of a lens using a probe and a reference fixture or a reference ball (e.g., Patent Document 2). In addition, there is also a known method for measuring the front-to-back eccentricity of a lens by measuring the positional relationship between the front and back of a lens using a camera instead of a probe (e.g., Patent Document 3).

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2001-56217

[0007] Patent Document 2: Japanese Patent Application Publication No. 2002-71344

[0008] Patent Document 3: Japanese Patent No. 5582188 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, it is difficult to measure the eccentricity of the object to be measured with high accuracy in the conventional eccentricity measuring method.

[0011] The present disclosure solves such a problem, and an object of the present disclosure is to provide an eccentricity measuring method and a measuring system capable of measuring the eccentricity of an object to be measured with high accuracy.

[0012] Means for solving problems

[0013] In order to achieve the above-mentioned purpose, one mode of the eccentricity measurement method involved in the present disclosure includes: a step of obtaining optical surface measurement data by measuring the optical surface of the object to be measured by a probe; a step of calculating the center position of the optical axis of the object to be measured based on the optical surface measurement data; a step of obtaining shape measurement data by measuring the shape of the object to be measured by a camera; a step of calculating the center position of the shape of the object to be measured based on the shape measurement data; and a step of calculating the eccentricity, wherein the eccentricity is the deviation between the center position of the optical axis and the center position of the shape.

[0014] In addition, one mode of the measuring system involved in the present disclosure comprises: a measuring machine having a probe for measuring an optical surface of an object to be measured and a camera for measuring an outer shape of the object to be measured; and a computing unit, which performs the following processing: calculating the center position of an optical axis of the object to be measured based on optical surface measurement data obtained by measuring the optical surface of the object to be measured by the probe, calculating the center position of an outer shape of the object to be measured based on outer shape measurement data obtained by measuring the outer shape of the object to be measured by the camera, and calculating eccentricity, wherein the eccentricity is the deviation between the center position of the optical axis and the center position of the outer shape.

[0015] Effects of the Invention

[0016] According to the present disclosure, the eccentricity of the object to be measured can be measured with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The diagram shows a case where a lens as a measurement object is tilted and a case where it is not tilted.

[0018] Figure 2 This is a diagram showing the configuration of a measurement system according to Embodiment 1.

[0019] Figure 3 This is a diagram for explaining the rotation mechanism in the measurement system according to the first embodiment.

[0020] Figure 4 This is a diagram for explaining the principle of the eccentricity measuring method using the measuring system involved in the first embodiment.

[0021] Figure 5 This is a flowchart of the eccentricity measuring method involved in Embodiment 1.

[0022] Figure 6 The diagram shows a case where the sphericity of a true sphere as a calibration jig is high and a case where the sphericity of a true sphere is low.

[0023] Figure 7 This is a perspective view of a calibration jig used in a modified example of the first embodiment.

[0024] Figure 8 It is a diagram showing the vertex position and the center position of the correction jig in a modification of the first embodiment.

[0025] Fig. 9 This is a diagram for explaining a calibration method using a calibration jig in a modified example of the first embodiment.

[0026] Fig.10 This is a diagram for explaining a method of calculating an offset amount and a correction amount in a modified example of the first embodiment.

[0027] Fig.11 This is a flowchart of the eccentricity measurement method involved in embodiment 2.

[0028] Fig.12 This is a flowchart of a method for calculating the optical axis center position in the eccentricity measuring method involved in Embodiment 2.

[0029] Fig.13 This is a flowchart of a method for calculating the center position of the outer shape in the eccentricity measurement method involved in the second embodiment.

[0030] Explanation of symbols

[0031] 1. Measurement system

[0032] 2 Lenses

[0033] 2a Surface

[0034] 2b Back

[0035] 2c Edge

[0036] 3Calibration fixture

[0037] 3a Reference convex part

[0038] 3b Fiducial Mark

[0039] 3c flat panel

[0040] 101st measurement section

[0041] 11 Probe

[0042] 20 The second measurement unit

[0043] 21 cameras

[0044] 30 workbenches

[0045] 40 Rotating mechanism

[0046] 50 Processing Department

[0047] 51 Operation unit

[0048] 52 Control Department

[0049] 60 Input and output devices

[0050] C1 optical axis center position

[0051] C2 shape center position

[0052] E Eccentricity DETAILED DESCRIPTION

[0053] (Process until one embodiment of the present disclosure was obtained)

[0054] Before describing an embodiment of the present disclosure, a process leading to the achievement of one embodiment of the present disclosure will be described.

[0055] As mentioned above, Patent Document 3 discloses a method for measuring the front-to-back decentering of a lens by measuring the positional relationship between the front and back surfaces of the lens using a camera. In the decentering measurement method using a camera, if the lens to be measured is tilted, the measurement error becomes large. For example, Figure 1 As shown in (a), when the lens is not tilted, there is no deviation between the center position of the lens surface and the center position of the lens back, so the measurement error is small. Figure 1 As shown in (b), when the lens is tilted, the center position of the lens surface and the center position of the lens back are offset, and the measurement error becomes larger. Patent document 3 describes a method of adjusting the posture by measuring the flange surface of the lens, but in the case of a lens without a flange surface, the posture cannot be adjusted.

[0056] As described above, it is difficult to measure the eccentricity of the object to be measured with high accuracy in the conventional eccentricity measuring method.

[0057] Therefore, the inventors have conducted intensive research on such a subject, and as a result, have discovered a method for measuring the eccentricity of an object with high accuracy by using a probe and a camera to measure the object, and ultimately obtained a method and system for measuring eccentricity involved in the present disclosure.

[0058] Specifically, one mode of the eccentricity measurement method involved in the present disclosure includes: a step of obtaining optical surface measurement data by measuring the optical surface of the object to be measured by a probe; a step of calculating the center position of the optical axis of the object to be measured based on the optical surface measurement data; a step of obtaining shape measurement data by measuring the shape of the object to be measured by a camera; a step of calculating the center position of the shape of the object to be measured based on the shape measurement data; and a step of calculating the eccentricity, wherein the eccentricity is the deviation between the center position of the optical axis and the center position of the shape.

[0059] This makes it possible to measure the eccentricity of the object to be measured with high accuracy.

[0060] In addition, in one embodiment of the eccentricity measurement method involved in the present disclosure, it may be that, in the step of obtaining the optical surface measurement data, the setting posture of the object to be measured is calculated by performing a preliminary measurement action on the optical surface based on the probe, and the posture of the object to be measured is adjusted based on the setting posture using a rotation mechanism that can rotate at least around two axes. The optical surface measurement data for calculating the center position of the optical axis of the object to be measured is obtained by performing a formal measurement action based on the probe on the optical surface of the object to be measured whose posture is adjusted by the rotation mechanism.

[0061] This makes it possible to eliminate the inclination of the installation posture of the object to be measured, which is a major cause of error during eccentricity measurement, and thus the eccentricity of the object to be measured can be measured with higher accuracy.

[0062] In addition, in one embodiment of the eccentricity measurement method involved in the present disclosure, it may be that, in the step of calculating the center position of the outer shape, the setting posture of the object to be measured is calculated based on the optical surface measurement data, the coordinate transformation of the outer shape measurement data is performed based on the setting posture, and the center position of the outer shape is calculated based on the outer shape measurement data after the coordinate transformation.

[0063] Thus, even if the object to be measured is tilted, the eccentricity of the object to be measured can be measured with high accuracy.

[0064] In addition, in one embodiment of the eccentricity measurement method involved in the present disclosure, it may also include: a step of using a correction fixture having a reference convex portion to perform correction on the position of the probe and the position of the camera, the reference convex portion is a rotationally symmetrical shape and the maximum inclination angle is less than 90 degrees, in the correction step, the vertex position of the reference convex portion is calculated by measuring the vicinity of the center of the reference convex portion by the probe, the center position of the reference convex portion is calculated by measuring the edge portion of the reference convex portion by the camera, the difference between the vertex position and the center position is calculated as an offset, and the position of the probe and the camera are corrected according to the offset.

[0065] Thus, before measuring the object to be measured using the probe and the camera, the position of the probe and the camera can be calibrated, and thus the eccentricity of the object to be measured can be measured with higher accuracy.

[0066] In addition, in one embodiment of the eccentricity measurement method involved in the present disclosure, it may be that the correction fixture also has at least one reference mark that can be recognized by the camera, and in the step of performing the correction, the position of the reference mark is measured by the camera, and the correction amount is calculated using the relationship between the center position of the reference protrusion and the position of the reference mark, and the calculated correction amount is added to the offset.

[0067] This can improve the accuracy of the offset amount, and thus the position of the probe and the position of the camera can be calibrated with high accuracy. As a result, the eccentricity of the object to be measured can be measured with further high accuracy.

[0068] In one aspect of the eccentricity measuring method according to the present disclosure, the offset amount may be calculated by changing the installation angle of the correction jig at least once.

[0069] This makes it possible to further improve the accuracy of the offset amount, and thus to perform correction of the position of the probe and the position of the camera with further high accuracy.

[0070] In addition, one mode of the measuring system involved in the present disclosure comprises: a measuring machine having a probe for measuring an optical surface of an object to be measured and a camera for measuring an outer shape of the object to be measured; and a computing unit, which performs the following processing: calculating the center position of an optical axis of the object to be measured based on optical surface measurement data obtained by measuring the optical surface of the object to be measured by the probe, calculating the center position of an outer shape of the object to be measured based on outer shape measurement data obtained by measuring the outer shape of the object to be measured by the camera, and calculating eccentricity, wherein the eccentricity is the deviation between the center position of the optical axis and the center position of the outer shape.

[0071] According to this configuration, the eccentricity of the object to be measured can be measured with high accuracy.

[0072] In addition, in one embodiment of the measuring system involved in the present disclosure, the measuring machine may include: a rotating mechanism capable of rotating the object to be measured at least around two axes; and a control unit that controls the rotating mechanism, the computing unit calculates the setting posture of the object to be measured based on the optical surface measurement data obtained by pre-measuring the optical surface of the object to be measured by the probe, and before measuring the optical surface measurement data for calculating the center position of the optical axis, the control unit controls the rotating mechanism based on the setting posture to adjust the posture of the object to be measured.

[0073] According to this configuration, since the inclination of the installation posture of the object to be measured, which is a major cause of error during eccentricity measurement, can be eliminated, the eccentricity of the object to be measured can be measured with higher accuracy.

[0074] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the embodiments described below all represent a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, constituent elements, configuration positions of constituent elements, and connection methods shown in the following embodiments are examples, and their purpose is not to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, the constituent elements that are not recorded in the independent technical solutions representing the highest concept of the present disclosure are described as arbitrary constituent elements.

[0075] In addition, each figure is a schematic diagram and may not be strictly illustrated. In addition, in each figure, the same symbols are marked for substantially the same structure, and repeated descriptions are omitted or simplified. In addition, in this specification, terms such as "upper" and "lower" do not necessarily refer to the upper direction (vertically above) and the lower direction (vertically below) in absolute spatial identification. In addition, in this specification and the accompanying drawings, the X-axis, Y-axis and Z-axis represent the three axes of a three-dimensional orthogonal coordinate system. The X-axis and the Y-axis are axes that are orthogonal to each other and are both orthogonal to the Z-axis. In the present embodiment, the Z-axis direction is the vertical direction.

[0076] (Implementation Method 1)

[0077] First, use Figure 2 The configuration of the measurement system 1 according to the first embodiment of the present disclosure will be described. Figure 2 This is a diagram showing the configuration of a measurement system 1 according to the first embodiment.

[0078] like Figure 2 As shown, the measurement system 1 is a system for measuring an object to be measured, and includes a first measurement unit 10 , a second measurement unit 20 , a stage 30 , a rotation mechanism 40 , a processing unit 50 , and an input / output device 60 .

[0079] In this embodiment, the first measuring unit 10 and the second measuring unit 20 are connected and integrated to form a measuring machine. In this case, the measuring machine may include not only the first measuring unit 10 and the second measuring unit 20, but also a processing unit 50 and an input / output device 60. In addition, the measuring machine may also include a workbench 30 and a rotating mechanism 40. In this way, the measuring system 1 may also be configured as a measuring machine.

[0080] The object to be measured by the measuring system 1 is, for example, an optical component such as a lens. In the present embodiment, the object to be measured by the measuring system 1 is a lens 2 such as an aspheric lens. The lens 2 has a surface 2a (outer surface) as an optical surface of the outer side surface, a back surface 2b (inner surface) as an optical surface of the inner side surface, and an edge 2c (end edge).

[0081] The front surface 2a and the back surface 2b of the lens 2 are lens surfaces that give optical effects to light passing through the lens 2. When the lens 2 is an aspherical lens, the surface 2a is an aspherical surface. When the lens 2 is a spherical lens, the surface 2a is a spherical surface.

[0082] The edge 2c of the lens 2 constitutes the outer shape of the lens 2. In the present embodiment, the lens 2 has a flange portion, and the edge 2c is the end edge (outer peripheral side) of the flange portion of the lens 2. In addition, the flange portion of the lens 2 is annular, so the shape (outer shape line) of the edge 2c when the lens 2 is viewed from above is circular.

[0083] The first measuring unit 10 is a probe measuring unit having a probe 11 for measuring the optical surface of the lens 2 as the object to be measured. The probe 11 is a three-dimensional measuring probe having a probe whose front end contacts the object to be measured by a certain pressing force. The first measuring unit 10 measures the optical surface of the lens 2 through the probe 11. Specifically, the first measuring unit 10 obtains optical surface measurement data (probe measurement data) related to the surface 2a of the lens 2 by bringing the probe 11 into contact with the surface 2a as the optical surface of the lens 2. For example, as the optical surface measurement data, the first measuring unit 10 can obtain three-dimensional coordinate data (three-dimensional coordinate point group) in the XYZ space related to the three-dimensional shape of the surface 2a of the lens 2.

[0084] The second measuring unit 20 is a camera measuring unit having a camera 21 for measuring the outer shape of the lens 2 as the object to be measured. The second measuring unit 20 measures the outer shape of the lens 2 (the object to be measured) by the camera 21. Specifically, the second measuring unit 20 can obtain outer shape measurement data related to the outer shape of the lens 2 by photographing the edge 2c of the lens 2 by the camera 21. The outer shape measurement data is, for example, two-dimensional coordinate data (two-dimensional coordinate point group) in the XY plane. In the present embodiment, the outer shape of the lens 2 is a circle, and thus the outer shape measurement data of the lens 2 measured by the second measuring unit 20 is outer diameter measurement data about the circle. In addition, when the edge 2c of the lens 2 is photographed by the camera 21, the edge 2c may be photographed along the entire circumference of the edge 2c of the lens 2, or several locations within the entire circumference of the edge 2c may be photographed intermittently (for example, at equal intervals along the circumferential direction).

[0085] The workbench 30 is a table on which the object to be measured is placed. For example, a lens 2 is placed as the object to be measured on the workbench 30. In the present embodiment, a rotating mechanism 40 is provided on the workbench 30, and the lens 2 is placed on the rotating mechanism 40. That is, the lens 2 is placed on the workbench 30 via the rotating mechanism 40. In addition, the lens 2 may be placed directly on the workbench 30.

[0086] The workbench 30 can be arbitrarily moved on the XY plane by the control unit 52 of the processing unit 50. That is, the workbench 30 can be moved separately in the X-axis direction and the Y-axis direction. In this way, by moving the workbench 30, the first measuring unit 10 having the probe 11 or the second measuring unit 20 having the camera 21 can be arranged at an arbitrary position on the workbench 30. That is, by moving the workbench 30, the probe 11 or the camera 21 can be arranged at an arbitrary position on the surface 2a of the lens 2 placed on the workbench 30. In addition, the workbench 30 can also be configured to be movable not only in the X-axis direction and the Y-axis direction, but also in the Z-axis direction.

[0087] The rotation mechanism 40 has a function of rotating the lens 2 as the object to be measured at least around two axes. In this embodiment, the rotation mechanism 40 can rotate the lens 2 around three axes, namely, the X-axis, the Y-axis, and the Z-axis. Figure 3 As shown, the rotation mechanism 40 can change the posture of the lens 2 placed on the rotation mechanism 40 by sliding and rotating a part of the rotation mechanism 40. The rotation control of the rotation mechanism 40 can be performed by the control unit 52 of the processing unit 50.

[0088] The processing unit 50 has a computing unit 51 and a control unit 52. The processing unit 50 may also have a storage unit such as a memory. The computing unit 51 and the control unit 52 may be composed of, for example, a processor or a circuit. In this case, the computing unit 51 and the control unit 52 may be composed of separate processors or circuits, or may be composed of one processor or circuit as a whole. In addition, the processing unit 50 having the computing unit 51 and the control unit 52 may also be composed of an information processing device such as a computer. In this case, the processing described as the action of the processing unit 50 of the computing unit 51 and the like is executed by a computer. For example, a computer can execute a program by using hardware resources such as a processor (CPU), a memory, and an input / output circuit, thereby executing each process based on the processing unit 50. The results of each process may also be stored in a memory (not shown) in the processing unit 50. In addition, the processing unit 50 may be a terminal device arranged near the workbench 30, or a remote device such as a server.

[0089] The calculation unit 51 calculates the optical axis center position (optical center position) of the object to be measured based on the optical surface measurement data obtained by measuring the optical surface of the object to be measured by the probe 11. Figure 4 As shown in (a) of FIG. 2 , the calculation unit 51 calculates the optical axis center position C1 of the lens 2 based on the three-dimensional coordinate data acquired as optical surface measurement data by measuring the surface 2 a as the optical surface of the lens 2 by the probe 11 .

[0090] In addition, the calculation unit 51 calculates the center position of the outer shape of the object to be measured based on the outer shape measurement data obtained by measuring the outer shape of the object to be measured by the camera 21. Figure 4 As shown in (b) of FIG. 2 , the calculation unit 51 calculates the outer shape center position C2 of the lens 2 based on the two-dimensional coordinate data acquired as outer shape measurement data by measuring the outer shape of the lens 2 with the camera 21 .

[0091] Moreover, if Figure 4 As shown in (c) of FIG. 2 , the calculation unit 51 calculates the deviation between the optical axis center position C1 calculated based on the optical surface measurement data obtained by the probe 11 and the outer shape center position C2 calculated based on the outer shape measurement data obtained by the camera 21 as the decentering E of the lens 2 .

[0092] The operation unit 51 can further calculate the installation posture of the object to be measured based on the optical surface measurement data obtained by measuring the optical surface of the object to be measured by the probe 11. Specifically, the operation unit 51 can calculate the installation posture of the lens 2 based on the three-dimensional coordinate data (optical surface measurement data) obtained by measuring the optical surface of the lens 2 placed on the rotating mechanism 40, that is, the surface 2a, by the probe 11.

[0093] The control unit 52 has a function of controlling the rotation mechanism 40. That is, the control unit 52 can rotate the rotation mechanism 40. In this case, as described above, the surface 2a of the lens 2 placed on the rotation mechanism 40 is measured to calculate the installation posture of the lens 2 in advance, thereby adjusting the posture of the lens 2 (the object to be measured) by rotating the rotation mechanism 40 by the control unit 52 before measuring the optical surface measurement data for calculating the optical axis center position C1 of the lens 2 using the probe 11.

[0094] The input-output device 60 is a user interface having an input function for a user to input characters, numbers, etc. and an output function for outputting the calculation results obtained by the measurement system 1. The input-output device 60 is, for example, a terminal having a touch screen, but is not limited thereto. In addition, regarding the input-output device 60, an input device having an input function and an output device having an output function may be separately configured. In this case, the input device is a keyboard, a mouse, a button, etc., and the output device is a display, etc.

[0095] Next, for a method for measuring the decentering E of the lens 2 using the measuring system 1, refer to Figure 2 to Figure 4 and use Figure 5 To explain. Figure 5 This is a flowchart of the eccentricity measuring method involved in Embodiment 1.

[0096] First, if Figure 2As shown, a lens 2 (test lens) serving as a measurement object is placed on a table 30. In this embodiment, a rotation mechanism 40 provided on the table 30 is used, and the lens 2 is placed on the rotation mechanism 40. Then, the table 30 is moved so that the lens 2 and the probe 11 face each other.

[0097] Then, if Figure 5 As shown, the probe 11 measures the surface 2 a (test surface) which is the optical surface of the lens 2 , thereby acquiring optical surface measurement data for calculating the optical axis center position C1 of the lens 2 (steps S11 to S13 ).

[0098] In the present embodiment, after the installation posture of the lens 2 is adjusted, the optical surface measurement data for calculating the optical axis center position C1 of the lens 2 is acquired using the probe 11 .

[0099] In this case, first, the setting posture of the lens 2 is calculated by performing a preliminary measurement operation based on the probe 11 on the surface 2a of the lens 2 (step S11). Specifically, the surface 2a of the lens 2 is measured by the first measuring unit 10 having the probe 11. For example, the probe 11 is brought into contact with the surface 2a of the lens 2, and the probe 11 is slid over the entire range of the surface 2a of the lens 2 while the workbench 30 is moved, thereby measuring the overall three-dimensional shape of the surface 2a of the lens 2. The measurement data related to the three-dimensional shape measured by the first measuring unit 10 is sent to the calculation unit 51 as optical surface measurement data (three-dimensional coordinate data) for calculating the setting posture of the lens 2. Then, the calculation unit 51 calculates the setting posture of the lens 2 based on the acquired optical surface measurement data. For example, the calculation unit 51 calculates the degree of inclination (optical surface inclination amount) of the surface 2a of the lens 2 relative to the XY plane.

[0100] Next, the posture of the lens 2 is adjusted by the rotation mechanism 40 (step S12). Specifically, the posture of the lens 2 is adjusted by rotating the rotation mechanism 40 based on the setting posture of the lens 2 calculated in step S11 so that the posture of the lens 2 placed on the rotation mechanism 40 becomes a given posture. Specifically, the posture of the lens 2 is adjusted by the rotation control of the rotation mechanism 40 by the control unit 52 so that the inclination of the lens 2 relative to the XY plane disappears.

[0101] Then, the surface 2a (optical surface) of the lens 2 whose posture is adjusted by the rotation mechanism 40 is subjected to a formal measurement operation by the probe 11, and optical surface measurement data for calculating the optical axis center position C1 of the lens 2 is obtained (step S13). Specifically, the surface 2a of the lens 2 is measured by the first measurement unit 10 having the probe 11 in the same manner as step S11. For example, the probe 11 is brought into contact with the surface 2a of the lens 2, and the probe 11 is slid over the entire range of the surface 2a of the lens 2 while the worktable 30 is moved, thereby measuring the overall three-dimensional shape of the surface 2a of the lens 2 again. The measurement data related to the three-dimensional shape measured by the probe 11 is sent to the calculation unit 51 as optical surface measurement data (three-dimensional coordinate data) for calculating the optical axis center position C1 of the lens 2. That is, the calculation unit 51 obtains the optical surface measurement data for calculating the optical axis center position C1 of the lens 2.

[0102] Thus, in the present embodiment, before measuring the surface 2a of the lens 2 by the main measurement operation by the probe 11, the surface 2a of the lens 2 is measured by the preliminary measurement operation by the probe 11, the degree of inclination of the surface 2a of the lens 2 (optical surface inclination amount) is calculated, and the posture of the lens 2 is adjusted. Furthermore, after the posture of the lens 2 is adjusted, the surface 2a of the lens 2 is measured by the main measurement operation by the probe 11, thereby obtaining optical surface measurement data for calculating the optical axis center position C1 of the lens 2.

[0103] Next, based on the optical surface measurement data acquired in step S13, the optical axis center position C1 of the lens 2 is calculated (step S14). Specifically, the calculation unit 51 calculates the optical axis center position C1 of the lens 2 based on the optical surface measurement data acquired in step S13. For example, the calculation unit 51 calculates the vertex (optical surface vertex) of the surface 2a of the lens 2 as the optical axis center position C1.

[0104] Then, the camera 21 of the second measuring unit 20 measures the outer shape of the lens 2 to obtain outer shape measurement data (step S15). For example, the camera 21 captures an image of the edge 2c of the lens 2 to obtain two-dimensional coordinate data as outer shape measurement data related to the outer shape of the lens 2.

[0105] Next, the outer shape center position C2 of the lens 2 is calculated based on the outer shape measurement data acquired in step S15 (step S16). Specifically, the outer shape center position C2 of the lens 2 is calculated based on the outer shape measurement data acquired in step S15 by the calculation unit 51. For example, when the outer shape of the lens 2 is circular, the calculation unit 51 calculates the center of the circle constituting the outer shape of the lens 2 as the outer shape center position C2 in the XY plane.

[0106] Then, based on the optical axis center position C1 calculated in step S14 and the outer shape center position C2 calculated in step S16, the eccentricity E of the lens 2 is calculated (step S17). Specifically, the difference between the optical axis center position C1 calculated based on the optical surface measurement data obtained by the probe 11 and the outer shape center position C2 calculated based on the outer shape measurement data obtained by the camera 21, i.e., the deviation amount, is calculated by the calculation unit 51 as the eccentricity E of the lens 2.

[0107] As described above, according to the eccentricity measuring method and measuring system 1 of the present embodiment, the eccentricity E of the lens 2 as the object to be measured is measured using the first measuring unit 10 having the probe 11 and the second measuring unit 20 having the camera 21. Specifically, Figure 4 As shown in (a), based on the optical surface measurement data (probe measurement data) obtained by measuring the surface 2a of the lens 2 by the probe 11, the optical axis center position C1 of the lens 2 is calculated, as shown in FIG. Figure 4 As shown in (b), based on the shape measurement data (camera measurement data) obtained by measuring the shape of the lens 2 by the camera 21, the shape center position C2 of the lens 2 is calculated, and then, as shown in Figure 4 As shown in (c) of FIG. 2 , the calculated deviation amount between the optical axis center position C1 and the outer shape center position C2 is calculated as the decentering E of the lens 2 .

[0108] This makes it possible to measure the decentering E of the lens 2 as the object to be measured with high accuracy. Therefore, based on the decentering E, the quality of the lens 2 can be determined with high accuracy, and a mass production mold for manufacturing the lens 2 can be improved with high accuracy.

[0109] In addition, in the eccentricity measurement method and measurement system 1 involved in the present embodiment, the setting posture of the lens 2 is calculated by performing a preliminary measurement action based on the probe 11 on the optical surface of the lens 2, and the posture of the lens 2 is adjusted based on the setting posture of the lens 2 using the rotation mechanism 40. Then, the optical surface measurement data for calculating the optical axis center position C1 of the lens 2 is obtained by performing a formal measurement action based on the probe 11 on the optical surface of the lens 2 whose posture is adjusted by the rotation mechanism 40.

[0110] This can eliminate the inclination of the installation posture of the lens 2 that is a major cause of error during decentering measurement, and thus the decentering E of the lens 2 can be measured with higher accuracy.

[0111] (Variation of Implementation Example 1)

[0112] Next, a modification of the eccentricity measuring method according to the first embodiment will be described below.

[0113] In the measurement system 1 in the above-mentioned first embodiment, the position of the probe 11 and the position of the camera 21 are different. That is, the measurement position based on the probe 11 and the measurement position based on the camera 21 are different. Therefore, the positional relationship between the probe 11 and the camera 21 can be calculated, and the measurement results obtained by the probe 11 and the measurement results obtained by the camera 21 can be processed in advance using the same coordinates. That is, before performing the measurement based on the probe 11 and the measurement based on the camera 21 in order to measure the eccentricity of the lens 2 as the object to be measured, the distance (offset) between the contact position of the probe 11 in the lens 2 as the object to be measured and the focus position of the camera 21 can be calculated, and the position of the probe 11 and the position of the camera 21 can be corrected in advance.

[0114] When performing such a calibration, it is considered to use a true sphere as a calibration fixture. In this case, Figure 6 As shown in (a), when the sphericity of the sphere 3X is high, the difference between the center position of the sphere 3X calculated by the probe 11 and the center position of the sphere 3X calculated by the camera 21, that is, the error of the center position is small. Figure 6 As shown in (b), when the sphericity of the true sphere 3X is low, the difference between the center position of the true sphere 3X calculated by the probe 11 and the center position of the true sphere 3X calculated by the camera 21, that is, the error of the center position becomes large.

[0115] Furthermore, if the true sphere 3X is used as the calibration jig, a shadow is generated in the XY plane at a portion of the true sphere 3X where the tilt angle is 90 degrees or more. Therefore, when the camera 21 measures the edge of the true sphere 3X, there is a concern that the edge detection accuracy may decrease.

[0116] Therefore, in this modification, a real ball is not used but a Figure 7 The calibration jig 3 shown is used to calibrate the position of the probe 11 and the position of the camera 21 . Figure 7 This is a perspective view of a correction jig 3 used in a modification of the first embodiment.

[0117] like Figure 7 As shown, the calibration jig 3 has a reference protrusion 3a and a reference mark 3b. Further, the calibration jig 3 has a flat plate 3c. The reference protrusion 3a and the reference mark 3b are formed on the flat plate 3c.

[0118] The reference protrusion 3a is a protrusion having a rotationally symmetrical shape and a maximum inclination angle of 90 degrees or less. As an example, the reference protrusion 3a is a hemisphere and is provided at the center of the flat plate 3c.

[0119] The reference mark 3b is a plane figure that can be recognized by the camera 21. As an example, the reference mark 3b is a circle of a color such as black. The reference mark 3b is printed around the reference protrusion 3a in the plane plate 3c. In addition, in this modification, the reference mark 3b is one, but it is not limited to this. For example, the reference mark 3b can also be formed in multiple numbers around the reference protrusion 3a.

[0120] Next, a method of calculating the distance between the contact position of the probe 11 and the focus position of the camera 21 , that is, the offset amount, using the calibration jig 3 will be described.

[0121] The setting posture of the calibration jig 3 when the reference mark 3b is located at the lower right of the reference protrusion 3a is set to the state of "0° setting". Figure 8 As shown, it is assumed that the vertex position P and the center position C of the reference convex portion 3a do not coincide with each other in the state of the 0° setting.

[0122] In this case, first, Fig. 9 As shown in (a), the calibration fixture 3 is placed on the workbench 30 (see Figure 2 ), use the probe 11 and the camera 21 to measure the reference protrusion 3a and the reference mark 3b.

[0123] Specifically, the vertex position P of the reference convex portion 3a is calculated by measuring the vicinity of the center of the reference convex portion 3a with the probe 11. For example, three-dimensional measurement data (three-dimensional coordinate point group) related to the surface of the reference convex portion 3a is acquired by bringing the probe 11 into contact with the surface of the reference convex portion 3a, and the vertex position P of the reference convex portion 3a is calculated based on the acquired three-dimensional measurement data.

[0124] In addition, the center position C of the reference convex portion 3a is calculated by measuring the edge portion of the reference convex portion 3a by the camera 21. For example, two-dimensional measurement data (two-dimensional coordinate point group) related to the outer shape of the reference convex portion 3a is obtained by measuring the edge portion of the reference convex portion 3a by the camera 21, and the center position C of the reference convex portion 3a is calculated based on the obtained two-dimensional measurement data.

[0125] The difference between the vertex position P and the center position C is the offset. In the present modification, the offset is calculated by changing the installation angle of the correction jig 3 three or more times.

[0126] For example, when the setting angle of the correction fixture 3 is changed three times, Fig. 9 As shown in (b) to (d), the correction fixture 3 is rotated at 90° intervals, and the correction fixture 3 is respectively set at 90° ( Fig. 9 (b)), 180° setting state ( Fig. 9 (c)) and the 270° setting state ( Fig. 9 In (d)), the vertex position P and the center position C of the reference convex portion 3a are calculated in the same manner as in the state of 0° setting. At this time, the vertex positions of the reference convex portion 3a calculated in the 0° setting, 90° setting, 180° setting, and 270° setting are respectively set to P1, P2, P3, and P4. Similarly, the center positions of the reference convex portion 3a calculated in the 0° setting, 90° setting, 180° setting, and 270° setting are respectively set to C1, C2, C3, and C4.

[0127] Then, if Fig.10 As shown in (a), under the 0° setting, 90° setting, 180° setting, and 270° setting, the center position C is subtracted from the vertex position P, and a coordinate data group with the center position C as the origin is created, and the average of the four coordinate data is used as the offset. Specifically, under the 0° setting, 90° setting, 180° setting, and 270° setting, four coordinate data are created after the center position C is subtracted from the vertex position P, and the average of the four coordinate data is used as the offset.

[0128] In addition, if Fig.10 As shown in (b), the coordinates of the vertex position P and the center position C of the reference convex portion 3a are synthesized according to the obtained offset, and the coordinates of the straight line connecting the reference mark 3b and the center position C of the reference convex portion 3a are rotated so that the reference mark 3b is set at 0°, and the difference between the vertex position P and the center position C of the reference convex portion 3a at this time is calculated as the correction amount (offset correction amount). The calculated correction amount is added to the offset. In this way, the correction amount is calculated using the relationship between the center position C of the reference convex portion 3a of the calibration fixture 3 and the position of the reference mark 3b, and the calculated correction amount is added to the offset.

[0129] Then, the position of the probe 11 and the position of the camera 21 are corrected (offset) based on the offset amount to which the correction amount is added.

[0130] By calculating the offset amount using the calibration jig 3 and calibrating the position of the probe 11 and the position of the camera 21 in advance, when measuring the eccentricity E of the lens 2 as in the first embodiment, the eccentricity can be measured with high accuracy.

[0131] In particular, in this modified example, the calibration fixture 3 having the reference protrusion 3a and the reference mark 3b is used, and the reference mark 3b is used to correct the relationship between the vertex position P and the center position C of the reference protrusion 3a, so that the offset can be calculated with high precision. That is, the position of the probe 11 and the position of the camera 21 can be calibrated with high precision. As a result, when measuring the eccentricity E of the lens 2, the eccentricity E can be measured with further high precision.

[0132] In addition, in this modified example, when calculating the correction amount added to the offset, the setting angle of the correction fixture 3 is changed only three times, but it is not limited to this. For example, the setting angle of the correction fixture 3 may be changed only once (for example, only 0° setting and 180° setting), or it may be changed four or more times. By changing it four or more times, it is expected that the accuracy of the correction amount added to the offset will be improved. As a result, the position of the probe 11 and the position of the camera 21 can be further accurately corrected, and when measuring the eccentricity E of the lens 2, the eccentricity E can be measured with higher accuracy.

[0133] (Implementation Method 2)

[0134] Next, use Fig.11 The eccentricity measuring method according to the second embodiment will be described. Fig.11 This is a flowchart of the eccentricity measurement method involved in embodiment 2.

[0135] In this embodiment, the eccentricity E of the lens 2 is measured using the measuring system 1 in the above-mentioned embodiment 1, but unlike the above-mentioned embodiment 1, the eccentricity E of the lens 2 is measured without using the rotating mechanism 40. That is, in the above-mentioned embodiment 1, the eccentricity E of the lens 2 is measured using the probe 11 and the camera 21 after adjusting the installation posture of the lens 2 using the rotating mechanism 40, but in this embodiment, the eccentricity E of the lens 2 is measured using the probe 11 and the camera 21 without adjusting the installation posture of the lens 2 using the rotating mechanism 40. Therefore, in this embodiment, the lens 2 as the object to be measured may also be directly placed on the workbench 30.

[0136] like Fig.11 As shown, in the eccentricity measuring method according to the present embodiment, first, the surface 2a (optical surface) of the lens 2 is formally measured by the probe 11, thereby obtaining optical surface measurement data for calculating the optical axis center position C1 of the lens 2 (step S21). Specifically, similarly to step S13 in the eccentricity measuring method according to the first embodiment, the probe 11 is brought into contact with the surface 2a of the lens 2 to measure the three-dimensional shape of the surface 2a of the lens 2, thereby obtaining optical surface measurement data (three-dimensional coordinate data) for calculating the optical axis center position C1 of the lens 2.

[0137] Next, the optical axis center position C1 of the lens 2 and the installation posture of the lens 2 are calculated based on the optical surface measurement data obtained in step S21 (step S22). The method of calculating the optical axis center position C1 of the lens 2 based on the optical surface measurement data measured by the probe 11 will be described later. In addition, the method of calculating the installation posture of the lens 2 based on the optical surface measurement data measured by the probe 11 is the same as that in the above-mentioned embodiment 1.

[0138] Then, the camera 21 measures the outer shape of the lens 2 to obtain outer shape measurement data (step S23). Specifically, similarly to step S15 in the eccentricity measurement method of the first embodiment, the camera 21 captures the edge 2c of the lens 2 to obtain two-dimensional coordinate data as outer shape measurement data related to the outer shape of the lens 2.

[0139] Next, the outer shape center position C2 of the lens 2 is calculated based on the outer shape measurement data acquired in step S23 (step S24). In this embodiment, since the posture of the lens 2 is not adjusted by the rotation mechanism 40, the coordinate transformation of the outer shape measurement data is performed based on the installation posture of the lens 2 calculated in step S22, and the outer shape center position C2 is calculated based on the outer shape measurement data after the coordinate transformation. In addition, the details of step S24 will be described later.

[0140] Then, based on the optical axis center position C1 calculated in step S22 and the outer shape center position C2 calculated in step S24, the eccentricity E of the lens 2 is calculated (step S25). Specifically, similarly to step S17 in the eccentricity measurement method of the first embodiment, the difference between the optical axis center position C1 calculated based on the optical surface measurement data obtained by the probe 11 and the outer shape center position C2 calculated based on the outer shape measurement data obtained by the camera 21, i.e., the deviation amount, is calculated by the calculation unit 51 as the eccentricity E of the lens 2.

[0141] Here, for the details of the above-mentioned step S22 for calculating the optical axis center position C1 in this embodiment, use Fig.12 To explain. Fig.12 This is a flowchart of a method for calculating the optical axis center position C1 in the eccentricity measuring method according to the second embodiment.

[0142] like Fig.12 As shown, first, the initial coordinate transformation parameters from the measured coordinate system to the designed coordinate system are specified (step S221). That is, the initial values ​​of the coordinate transformation parameters are set. The initial values ​​of the coordinate transformation parameters can use a predetermined value, and can also use an arbitrary value. Here, the number of coordinate transformation parameters is a total of 6 parameters, which are 3 parameters of the movement amounts in the X-axis direction, the Y-axis direction, and the Z-axis direction, and 3 parameters of the rotation amounts around the X-axis, the Y-axis, and the Z-axis.

[0143] Next, the optical surface measurement data acquired in step S21 is subjected to coordinate transformation (step S222 ). Specifically, the coordinates of the optical surface measurement data are transformed using the initial values ​​of the coordinate transformation parameters specified in step S221 .

[0144] Then, the X coordinate and the Y coordinate are substituted into the design formula to calculate the reference coordinates (step S223). Specifically, the X coordinate and the Y coordinate values ​​of the three-dimensional coordinate point group p11~pln included in the optical surface measurement data after the coordinate transformation in step S222 are substituted into the design formula representing the shape of the lens 2 as the object to be measured. The reference coordinates are calculated for each measurement point by substituting the X coordinate and the Y coordinate of the three-dimensional coordinate point group p11~pln into the design formula. As an example of the design formula, a rotationally symmetric aspheric formula can be cited. The rotationally symmetric aspheric formula is a matrix variable polynomial, for example, represented by the following (Formula 1).

[0145]

Mathematical formula 1

[0146]

[0147] In (Formula 1), "h" is the distance from the center, "c" is the inverse of the radius of curvature, "k" is the cone coefficient, and "Ai" represents the polynomial coefficient. The number of constants in the prepared reference formula is a total of 22. In addition, "h" is calculated by the following (Formula 2) based on the X coordinate and the Y coordinate.

[0148]

Mathematical formula 2

[0149]

[0150] Next, the measurement point and the reference coordinates are compared to calculate the mean square error (step S224). Specifically, the three-dimensional coordinates of the measurement point of the optical surface measurement data are compared with the three-dimensional coordinates of each reference coordinate. For example, the Z coordinate of the measurement point of the optical surface measurement data is compared with the Z coordinate of each reference coordinate. Then, the mean square error (RMSE; Root Mean Square Error) of the difference obtained by comparison is calculated. The calculated mean square error represents the difference between the Z coordinate of each measurement point and the reference coordinate.

[0151] Then, the coordinate transformation parameters are updated (step S225 ). Specifically, the coordinate transformation parameters are updated so that the difference between the three-dimensional coordinates of each measurement point and the three-dimensional coordinates of the reference coordinates becomes minimum.

[0152] Next, determine whether the mean square deviation calculated in step S224 is less than a given threshold value (step S226). And, when the mean square deviation calculated in step S224 is less than the given threshold value (yes in S226), end the process. On the other hand, when the mean square deviation calculated in step S224 is greater than the given threshold value (no in S226), repeat the process of steps S222 to S225. When the result of repeated calculation of the coordinate transformation parameters is that the mean square deviation is lower than the given threshold value or converges to a given value and no longer changes, end the repeated calculation and determine the coordinate transformation parameters. In addition, when the value of the newly calculated mean square deviation increases compared to the previous calculation result, it can be determined that the mean square deviation has converged.

[0153] Then, the optical axis center position C1 is calculated (step S227). Specifically, the coordinate transformation of the [0, 0, 0] origin of the design coordinate system is performed using the coordinate transformation parameters to obtain the optical axis center position C1 in the measurement coordinate system. As for the calculation formula, the optical axis center position C1 is expressed by the following (Formula 3) by using the position vector P created based on the three parameters of the movement amounts in the X-axis direction, the Y-axis direction, and the Z-axis direction among the coordinate transformation parameters, and the rotation matrix R created based on the three parameters of the rotation amounts around the X-axis, the Y-axis, and the Z-axis. In addition, in (Formula 3), R T is the transposed matrix of the rotation matrix R.

[0154]

Mathematical formula 3

[0155]

[0156] In this embodiment, the optical axis center position C1 can be calculated based on the optical surface measurement data acquired using the probe 11 in this manner.

[0157] Next, regarding the details of the above-mentioned step S24 for calculating the outer shape center position C2 in this embodiment, use Fig.13 To explain. Fig.13 This is a flowchart of a method for calculating the outer shape center position C2 in the eccentricity measuring method involved in the second embodiment.

[0158] In this case, if Fig.13 As shown, first, based on the shape measurement data acquired in step S23, the three-dimensional coordinate point group of the shape of the lens 2 is calculated (step S241). Specifically, by image processing, the three-dimensional coordinate point group of the shape of the lens 2 is calculated based on the shape measurement data (camera measurement data). Here, the shape measurement data includes a measurement image and a measurement coordinate, edge detection processing is applied to the measurement image, and the edge detection points obtained are transformed into the measurement coordinate system based on the measurement coordinates to obtain the three-dimensional coordinate point group p21~p2n.

[0159] Here, when the outer shape of the lens 2 to be measured is larger than the field of view of the camera, multiple outer shape measurement data are obtained, but in this case, the step of calculating the three-dimensional coordinate point group of the outer shape of the lens 2 is performed multiple times, and the calculated multiple three-dimensional coordinate point groups are merged into one three-dimensional coordinate point group.

[0160] Next, the X-coordinate and the Y-coordinate are used to approximate the circle by the least square method (step S242). Specifically, the circle is approximated by the least square method using the values ​​of the X-coordinate and the Y-coordinate of the three-dimensional coordinate point group p21 to p2n. Here, the equation of the circle is represented by the following (Equation 4). In (Equation 4), "a" is the X-coordinate of the center of the circle, "b" is the Y-coordinate of the center of the circle, and "r" is the radius of the circle.

[0161]

Mathematical formula 4

[0162]

[0163] Then, the contour center position C2 is calculated based on the circle coefficient and the measured coordinates (step S243). Specifically, the contour center position C2 is calculated by setting a and b calculated in step S242 as the X coordinate of the contour center and the Y coordinate of the contour center, and setting the Z coordinate of the measured coordinates of the contour measurement data as the Z coordinate of the contour center. In addition, when there are a plurality of contour measurement data, the Z coordinate of the measured coordinates of the contour measurement data may be set as the average value.

[0164] In this embodiment, the outer shape center position C2 can be calculated based on the outer shape measurement data acquired using the camera 21 in this way.

[0165] As described above, in the eccentricity measuring method according to the present embodiment, similarly to the above-mentioned first embodiment, the eccentricity E of the lens 2 is measured using the first measuring unit 10 having the probe 11 and the second measuring unit 20 having the camera 21. Specifically, the optical axis center position C1 of the lens 2 is calculated based on the optical surface measurement data obtained by measuring the surface 2a of the lens 2 by the probe 11, and the outer shape center position C2 of the lens 2 is calculated based on the outer shape measurement data obtained by measuring the outer shape of the lens 2 by the camera 21, and then, the deviation amount between the calculated optical axis center position C1 and the outer shape center position C2 is calculated as the eccentricity E of the lens 2.

[0166] Thus, similarly to the first embodiment, the decentering E of the lens 2 as the object to be measured can be measured with high accuracy.

[0167] Furthermore, in the eccentricity measurement method involved in the present embodiment, unlike the above-mentioned embodiment 1, the posture of the lens 2 is not controlled by the rotation mechanism 40, but in the step of calculating the outer shape center position C2, the setting posture of the lens 2 is calculated based on the optical surface measurement data, the coordinate transformation of the outer shape measurement data is performed based on the setting posture, and the outer shape center position C2 is calculated based on the outer shape measurement data after the coordinate transformation.

[0168] Thus, even if the lens 2 as the object to be measured is tilted, the decentering E of the lens 2 can be measured with high accuracy. That is, the decentering E of the lens 2 can be measured with high accuracy regardless of the posture of the lens 2.

[0169] Although the description is omitted, in this embodiment, before measuring the lens 2 as the object to be measured, the position of the probe 11 and the position of the camera 21 can be calibrated using the calibration fixture 3, as in the modified example of the above-mentioned embodiment 1. This allows the eccentricity E of the lens 2 to be calculated with further high accuracy.

[0170] (Variation Example)

[0171] As mentioned above, although the eccentricity measuring method and the measuring system etc. which concern on this disclosure were demonstrated based on Embodiment 1 and 2, this disclosure is not limited to the said embodiment.

[0172] For example, in the above-mentioned embodiments 1 and 2, the table 30 is moved without moving the probe 11 (first measuring unit 10) and the camera 21 (second measuring unit 20), thereby making the lens 2 as the object to be measured placed on the table 30 face the probe 11 or the camera 21 for measurement, but the present invention is not limited to this. Specifically, the probe 11 or the camera 21 may be moved without moving the table 30, thereby making the lens 2 as the object to be measured placed on the table 30 face the probe 11 or the camera 21 for measurement, or the table 30 may be moved and the probe 11 or the camera 21 may be moved, thereby making the lens 2 face the probe 11 or the camera 21 for measurement. That is, when making the lens 2 placed on the table 30 face the probe 11 or the camera 21, it is sufficient to move the table 30 and the probe 11 or the camera 21 relatively.

[0173] In addition, various modifications that can be conceived by those skilled in the art to the above-mentioned embodiments and embodiments achieved by arbitrarily combining the components and functions in the embodiments without departing from the gist of the present disclosure are also included in the present disclosure.

[0174] Industrial Applicability

[0175] The technology disclosed in the present invention is useful as an eccentricity measurement method and a measurement system for measuring the eccentricity of an optical component such as a lens.

Claims

1. A method for measuring eccentricity, comprising: A step of acquiring optical surface measurement data by measuring the optical surface of the object to be measured with the probe; A step of calculating the optical axis center position of the object to be measured based on the optical surface measurement data; The step of acquiring shape measurement data by measuring the shape of the object to be measured by a camera; A step of calculating the center position of the outer shape of the object to be measured based on the outer shape measurement data; and A step of calculating eccentricity, wherein the eccentricity is the deviation between the center position of the optical axis and the center position of the outer shape.

2. The eccentricity measuring method according to claim 1, wherein: In the step of obtaining the optical surface measurement data, By performing a preliminary measurement operation on the optical surface using the probe to calculate the installation posture of the object to be measured, Using a rotation mechanism capable of rotating around at least two axes, adjusting the posture of the object to be measured based on the setting posture, By performing a main measurement operation by the probe on the optical surface of the object to be measured whose posture is adjusted by the rotation mechanism, optical surface measurement data for calculating the center position of the optical axis of the object to be measured is acquired.

3. The eccentricity measuring method according to claim 1, wherein: In the step of calculating the center position of the shape, calculating the installation posture of the object to be measured based on the optical surface measurement data, Based on the setting posture, coordinate transformation of the outer shape measurement data is performed; The outer shape center position is calculated based on the outer shape measurement data after coordinate transformation.

4. The eccentricity measuring method according to any one of claims 1 to 3, wherein: The eccentricity determination method further comprises: The step of calibrating the position of the probe and the position of the camera using a calibration fixture having a reference convex portion, wherein the reference convex portion is rotationally symmetrical and has a maximum inclination angle of 90 degrees or less, In the step of performing the correction, The apex position of the reference convex portion is calculated by measuring the vicinity of the center of the reference convex portion with the probe, The center position of the reference convex portion is calculated by measuring the edge portion of the reference convex portion by the camera, The difference between the vertex position and the center position is calculated as an offset, The position of the probe and the position of the camera are corrected according to the offset.

5. The eccentricity measuring method according to claim 4, wherein: The calibration fixture also has at least one reference mark that can be recognized by the camera, In the step of performing the correction, The camera determines the position of the reference mark. calculating a correction amount using a relationship between the center position of the reference convex portion and the position of the reference mark, The calculated correction amount is added to the offset amount.

6. The eccentricity measuring method according to claim 5, wherein: The offset amount is calculated by changing the setting angle of the correction jig at least once.

7. A measurement system comprising: a measuring machine having a probe for measuring an optical surface of an object to be measured and a camera for measuring an outer shape of the object to be measured; and Operation Department, The operation unit performs the following processing: calculating the center position of the optical axis of the object to be measured based on the optical surface measurement data acquired by measuring the optical surface of the object to be measured by the probe, calculating the center position of the outer shape of the object to be measured based on the outer shape measurement data acquired by measuring the outer shape of the object to be measured by the camera, The eccentricity is calculated, where the eccentricity is the deviation between the center position of the optical axis and the center position of the outer shape.

8. The measuring system according to claim 7, wherein: The measuring machine has: A rotating mechanism capable of rotating the object to be measured at least around two axes; and a control unit, controlling the rotating mechanism, The calculation unit calculates the installation posture of the object to be measured based on the optical surface measurement data acquired by measuring the optical surface of the object to be measured in advance by the probe, Before measuring the optical surface measurement data for calculating the optical axis center position, the control unit controls the rotation mechanism based on the installation posture to adjust the posture of the object to be measured.

Images