X-ray measurement device

Abstract

To prevent a decrease in measurement accuracy for a target object in a non-contact manner.SOLUTION: An X-ray measurement device 1 for measuring an object 2 using X-rays includes an acquisition unit that irradiates the object 2 with X-rays and acquires diffraction rings detected on a detection surface correspondingly to each of a plurality of rotation angles when the object 2 is rotated, a calculation unit that calculates a distance between the detection surface and the object 2 using the diffraction rings correspondingly to each of the plurality of rotation angles, and an estimation unit that estimates at least one of the amount of eccentricity of the object 2 and the variation in the surface shape of the object 2 in the rotation direction based on the distance corresponding to each rotation angle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an X-ray measurement device. [Background technology]

[0002] To measure an object, one method is to irradiate the object with X-rays and detect the diffraction rings of the X-rays diffracted by the object.The object can then be analyzed based on the detected diffraction rings.

[0003] For example, Patent Document 1 discloses the use of a three-dimensional shape measuring device that measures three-dimensional shapes in addition to an X-ray measuring device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6600930 Summary of the Invention [Problem to be solved by the invention]

[0005] When measuring the state of an object, a measuring device such as that described in Patent Document 1 is used. When measuring an object using a contact-type measuring device, scratches or the like may occur on the surface of the object. Furthermore, when measuring an object using a non-contact-type measuring device that uses a laser, for example, the measurement may be affected by the surface of the object (e.g., gloss), which may reduce the measurement accuracy.

[0006] In view of the above-mentioned problems, an object of the present invention is to provide an X-ray measurement device that can suppress a decrease in measurement accuracy for an object without contact. [Means for solving the problem]

[0007] In order to solve the above problems, the X-ray measurement device of the present invention is an X-ray measurement device that measures an object using X-rays, and includes an acquisition unit that irradiates the object with X-rays and acquires diffraction rings detected on a detection surface corresponding to each of a plurality of rotation angles when the object is rotated, a calculation unit that calculates the distance between the detection surface and the object using the diffraction rings corresponding to each of the plurality of rotation angles, and an estimation unit that estimates at least one of the amount of eccentricity of the object and the variation in the surface shape of the object in the rotation direction based on the distance corresponding to each of the rotation angles.

[0008] In the X-ray measurement device, the object has a cylindrical shape.

[0009] Furthermore, in the X-ray measurement device, the estimation unit includes an averaging unit that calculates an average value of the distances corresponding to each of the rotation angles, a subtraction unit that calculates a difference between the distances and the average value, an approximation unit that approximates a distribution of the difference amounts with respect to the rotation angles using a sine wave or cosine wave curve, and an identification unit that identifies at least one of the eccentricity amount and the variation using the approximated curve.

[0010] In the X-ray measurement apparatus, the specifying unit determines the amplitude and initial phase of the approximated curve as the amount of eccentricity.

[0011] In the X-ray measurement apparatus, the specifying unit determines the amount of variation corresponding to the rotation angle to be a value obtained by subtracting the value of the curve corresponding to the rotation angle from the difference amount for the rotation angle. [Effects of the Invention]

[0012] According to the X-ray measurement device of the present invention, it is possible to suppress a decrease in measurement accuracy for an object. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing an example of the configuration of an X-ray measurement apparatus according to an embodiment of the present invention. [Figure 2]FIG. 1 is a diagram illustrating an example of the configuration of an X-ray measurement device. [Figure 3] 10A and 10B are diagrams illustrating an example of a diffraction ring detected by a detection unit. [Figure 4] FIG. 10 is a diagram showing the relationship between peak positions and distances. [Figure 5] FIG. 10 is a diagram illustrating an example of a distribution of distances relative to rotation angles. [Figure 6] FIG. 10 is a diagram illustrating an example of a distribution of difference amounts with respect to rotation angles. [Figure 7] FIG. 10 is a diagram illustrating an example of distribution of variation amounts with respect to rotation angles. [Figure 8] 10 is a flowchart illustrating an example of a processing flow by a processing unit. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted where appropriate.

[0015] === Implementation form === <Overall structure> FIG. 1 is a diagram showing an example of the configuration of an X-ray measurement device 1 according to this embodiment. The X-ray measurement device 1 performs measurement by irradiating an object 2 with X-rays and detecting the X-rays diffracted by the object 2. The object 2 is a sample to be analyzed, and is, for example, an automobile part such as a gear, crankshaft, or shaft, or other part. For example, the object 2 is a cylindrical object.

[0016] In this embodiment, the X-ray measurement device 1 measures the amount of eccentricity of the object 2 and the shape variation in the circumferential direction.

[0017] 1, the X-ray measurement device 1 has a main body 10, and its main components are a tube 11, a collimator 12, a substrate 13, and a detection unit 14. The X-ray measurement device 1 also has a processing unit 15.

[0018] Tube 11 functions as an irradiation unit that generates X-rays and irradiates the generated X-rays toward object 2. Tube 11 is made of a material such as glass or metal.

[0019] Collimator 12 has the function of adjusting the irradiation range of the X-rays generated by tube 11. Collimator 12 is provided below (on the substrate side of) tube 11 and extends toward substrate 13. The X-rays generated by tube 11 pass through collimator 12 and are irradiated onto object 2.

[0020] Substrate 13 is a plate-like member, and is provided with detection unit 14, which will be described later. Substrate 13 is provided with a hole, and collimator 12, which extends from the bulb 11 side, protrudes from this hole toward object 2 side.

[0021] Detector 14 has, for example, a rectangular shape and is provided on substrate 13 on the side of object 2 (the side opposite tube 11). Detector 14 detects X-rays diffracted from object 2. In detector 14, the surface that detects the diffracted X-rays is the detection surface. Specifically, detector 14 detects diffraction rings, which are annular diffraction images of the diffracted X-rays. Diffraction rings are also called Debye rings or Debye-Scherrer rings. Detector 14 is an imaging element for capturing an image of the diffraction rings on the detection surface, and is, for example, an SOI (Silicon on Insulator) sensor. For example, detector 14 is configured by two chips that are provided on either side of collimator 12. The number of chips is not limited.

[0022] The processing unit 15 is an information processing device that estimates the eccentricity and shape variation of the object 2 based on the detected diffraction ring. The processing unit 15 includes, for example, a control device, a communication device, and a storage device. The control device is mainly configured with a CPU (Central Processing Unit) and a memory. In the control device, the CPU executes a predetermined program stored in the memory or storage device, thereby functioning as various functional components described below. The communication device includes a communication interface for communicating with external devices. The storage device includes a hard disk or the like, and stores various programs and information required to execute processing in the control device, as well as information on processing results. The processing unit 15 may be configured with a single information processing device or multiple information processing devices. Furthermore, FIG. 1 only shows some of the main hardware components of the processing unit 15, and the processing unit 15 may include other components such as an operation device and a display device.

[0023] As shown in FIG. 2 , the X-ray measurement device 1 is also provided with a support unit 16 and a rotation unit 17. The support unit 16 supports the object 2. Specifically, the support unit 16 fixes the position of the object 2 relative to the main body unit 10. The rotation unit 17 is provided on the support unit 16. The rotation unit 17 has a chuck function that grips and fixes the object 2. As a result, the object 2 is fixed to the support unit 16 via the rotation unit 17. The rotation unit 17 also has a function of rotating the object 2. Specifically, the rotation unit 17 rotates the object 2 relative to the support unit 16. As a result, the object 2 rotates relative to the main body unit 10. In this embodiment, the rotation unit 17 rotates the object 2 about the rotation axis of the rotation unit 17 so that the cylindrical object 2 rotates in the circumferential direction. Furthermore, the rotation unit 17 is movable on the support unit 16 in a plane (xy plane) perpendicular to the rotation axis of the rotation unit 17. That is, the position of the rotating unit 17 on the plane is set relative to the support unit 16, and the object 2 is rotated at that position.

[0024] The rotation unit 17 is capable of rotating the object 2, and the angle by which the object 2 is rotated from a reference position is defined as the rotation angle. That is, the rotation unit 17 can rotate the object 2 to a predetermined rotation angle. For example, 360 rotation angles are set in 1-degree increments between 0 degrees and 359 degrees. In this case, the rotation unit 17 rotates the object 2 in 1-degree increments.

[0025] The X-ray irradiation direction is perpendicular to the rotation axis of the rotating unit 17 (or the object 2), for example. That is, the X-rays are irradiated to the object 2 at a distance so that the irradiation direction is perpendicular to the rotation axis. Specifically, the plane perpendicular to the rotation axis is parallel to the X-ray irradiation direction. Note that the rotation axis and the irradiation direction do not need to intersect as long as they are perpendicular to each other. The irradiation direction may or may not be parallel to the normal vector of the surface (side surface) of the object 2. For example, when stress estimation is performed, as shown in FIG. 2, it is preferable that the irradiation direction be oblique to the normal vector of the surface of the object 2. The irradiated X-rays are diffracted on the surface of the object 2 and detected as a diffraction ring by the detection unit 14. Note that, as shown in FIG. 2, the main body 10 is supported by the measurement support unit 18, and the position and posture of the main body 10 are adjustable. For example, the irradiation direction of the X-rays with respect to the object 2 is adjusted by the measurement support unit 18.

[0026] <Functional configuration> 1 is a block diagram showing an example of various functions in the processing unit 15. Position correction processing is performed by the functions in each block.

[0027] As shown in FIG. 1, the processing unit 15 includes an acquisition unit 31, a calculation unit 32, and an estimation unit 33 as main components.

[0028] The acquisition unit 31 acquires the diffraction rings detected when X-rays are irradiated onto the object 2. Specifically, the acquisition unit 31 acquires the diffraction rings detected by the detection unit .

[0029] FIG. 3 is a diagram showing an example of a diffraction ring detected on the detection plane of the detection unit 14. X-rays irradiated onto the object 2 are detected as a diffraction ring on the detection plane (each pixel), for example, as shown as C in FIG. 3. The angle of the diffraction ring in the circumferential direction (angle relative to a reference position) is the α angle. Portions of the diffraction ring are detected by each of the two chips that make up the detection unit 14. In other words, the α angle is the central angle of the diffraction ring on the detection plane of the detection unit 14. The detection unit 14 may detect a portion of the diffraction ring, or the entire circumference (entire) of the diffraction ring.

[0030] The acquisition unit 31 acquires the diffraction rings detected by the detection unit 14 corresponding to each of the multiple rotation angles when the object 2 is rotated. That is, after the object 2 is rotated to a predetermined rotation angle in the rotation unit 17, X-rays are irradiated onto the side of the object 2, and the acquisition unit 31 acquires the diffraction rings corresponding to the rotation angle. For example, if 360 rotation angles are set, 360 diffraction rings are acquired corresponding to each rotation angle. In this way, diffraction rings corresponding to each rotation angle of the object 2 are acquired. Each acquired diffraction ring is output to the calculation unit 32.

[0031] Returning to Fig. 1, the calculation unit 32 uses the diffraction ring to calculate the distance CL between the detection surface of the detection unit 14 and the object 2. The distance CL is the linear distance between the detection surface of the detection unit 14 and the surface of the object 2. The calculation unit 32 calculates the distance CL corresponding to each rotation angle using the diffraction ring corresponding to each rotation angle.

[0032] Specifically, the calculation unit 32 calculates the distance CL based on a diffraction profile corresponding to a predetermined α angle of the diffraction ring. FIG. 3 shows an example of a diffraction profile P1 when the α angle is α1. The diffraction profile shows the intensity distribution in the radial direction of the diffraction ring, with the vertical axis representing intensity and the horizontal axis representing radial position relative to the center of the diffraction ring. In the diffraction profile, the intensity is high at radial positions where the diffraction ring is detected and low at positions where the diffraction ring is not detected. The example in FIG. 3 shows that there is a peak of intensity Pm at peak position r. Peak position r indicates the position of the peak and indicates the distance relative to the center of the diffraction ring (the position of X-ray irradiation) in the diffraction profile.

[0033] Fig. 4 is a diagram showing the relationship between the peak position r and the distance CL. Fig. 4 shows an example of the path of the X-rays when the collimator 12 irradiates the object 2 with X-rays and the diffraction rings are detected by the detection unit 14. Note that Fig. 4 shows an example in which the X-rays are irradiated perpendicularly to the surface (side surface) of the object 2, but the same applies when the surface of the object 2 and the irradiation direction of the X-rays are not perpendicular. The relationship between the peak position r and the distance CL is given by the following formula (1).

[0034]

number

[0035] In equation (1), 2θ0 is the stress-free diffraction angle, which is the angle of the diffracted X-rays relative to the direction of X-ray irradiation. The stress-free rotation angle 2θ0 is the diffraction angle when X-rays are irradiated and diffracted on a stress-free standard sample made of a powder of the same material as the object 2 or a bulk material from which stress has been removed by heat treatment or the like. The stress-free rotation angle 2θ0 is set in advance depending on the object 2. The stress-free rotation angle 2θ0 is, for example, a value greater than 0 degrees and less than 180 degrees. Therefore, the calculation unit 32 calculates the peak position r from the diffraction profile, and calculates the distance CL from equation (1) using the peak position r and the stress-free rotation angle 2θ0.

[0036] The calculation unit 32 calculates the distance CL corresponding to each diffraction ring, thereby calculating the distance CL corresponding to each rotation angle.

[0037] While FIG. 3 illustrates an example in which the distance CL is calculated using a diffraction profile where the α angle is angle α1, the present invention is not limited to this. For example, the distance CL may be calculated using the average value of the peak positions r of the diffraction profiles at multiple α angles. Preferably, the calculation unit 32 calculates the distance CL using a diffraction profile at an α angle parallel to the rotation axis of the rotating unit 17 (or the object 2) in the diffraction ring. The α angle parallel to the rotation axis is angle α1 in FIG. 3. If the object 2 has a cylindrical shape, the detection surface of the detection unit 14 at the α angle parallel to the rotation axis is parallel to the surface of the object 2. Therefore, noise generated in the diffraction profile at an α angle parallel to the rotation axis is suppressed.

[0038] 1, in this manner, the distance CL corresponding to each rotation angle of the object 2 is calculated. Each calculated distance CL is output to the estimation unit 33.

[0039] The estimation unit 33 estimates at least one of the amount of eccentricity and the shape variation of the target object 2 based on the distance CL corresponding to each rotation angle. In this embodiment, a case where the estimation unit 33 estimates both the amount of eccentricity and the shape variation will be described as an example.

[0040] The amount of eccentricity of the object 2 is the amount of eccentricity when the object 2 is rotated by the rotating unit 17. Specifically, the amount of eccentricity indicates the deviation of the rotation axis (center of rotation) when the object 2 is actually rotated from the ideal rotation axis (center of rotation) for rotating the object 2. For example, eccentricity occurs due to deviation from the ideal position of the support unit 16, deviation from the ideal position of the rotating unit 17 relative to the support unit 16, deviation when the object 2 is fixed to the rotating unit 17, etc. If the object 2 has a cylindrical shape, ideally, a distance CL, which will be described later, is constant with respect to the rotation angle.

[0041] The shape variation of the object 2 refers to the variation in the surface shape in the rotational direction (circumferential direction) of the object 2. The variation is relative to the ideal surface shape. For example, if the object 2 has a cylindrical shape and is manufactured to have the ideal shape, the object 2 will ideally have a circular shape, but some variation in the surface shape will occur during the manufacturing process, processing process, etc.

[0042] As shown in FIG. 1, the estimation unit 33 includes an averaging unit 41, a subtraction unit 42, an approximation unit 43, and a specification unit 44.

[0043] The averaging unit 41 calculates the average value of the distances CL corresponding to each rotation angle. FIG. 5 is a diagram showing an example of the distribution of the distances CL with respect to the rotation angle. In FIG. 5, the vertical axis represents the distance CL and the horizontal axis represents the rotation angle. In FIG. 5, the distribution of the distances CL is indicated as L1. The averaging unit 41 calculates the average value for the distances CL for each rotation angle. In FIG. 5, the average value for the distribution of the distances CL is indicated as La. This allows the average value of the multiple calculated distances CL to be identified.

[0044] The subtraction unit 42 calculates the difference between the distance CL and the average value. Specifically, the subtraction unit 42 subtracts the distance CL for each rotation angle from the average value calculated by the averaging unit 41 to obtain the difference (amount of change in distance). Note that the difference is not limited to subtracting the distance CL from the average value, and the average value may be subtracted from the distance CL. The difference is calculated for each rotation angle.

[0045] Fig. 6 is a diagram showing an example of the distribution of the difference amount with respect to the rotation angle. In Fig. 6, the vertical axis represents the difference amount and the horizontal axis represents the rotation angle. In Fig. 6, the distribution of the difference amount is indicated as L2. In this manner, the subtraction unit 42 calculates the difference amount corresponding to each rotation angle.

[0046] The approximation unit 43 approximates the distribution of the difference amount with respect to the rotation angle using a sine wave or cosine wave curve. In this embodiment, an example in which approximation is performed using a cosine wave curve (cosine function) will be described. Note that the same can be applied to the case in which approximation is performed using a sine wave curve (sine function). The approximation unit 43 approximates the distribution of the difference amount shown as L2 in FIG. 6 using a cosine curve. Specifically, the approximation unit 43 approximates the distribution of the difference amount using the following equation (2).

[0047]

number

[0048] In equation (2), F is the difference amount, φ is the rotation angle, R is the amplitude of the cosine wave curve, and ξ is the initial phase of the cosine wave curve.

[0049] 6 shows a curve L3 obtained by approximating the distribution of the difference amount L2 with a cosine wave. In this way, a cosine curve is fitted to the distribution of the difference amount.

[0050] The specifying unit 44 specifies at least one of the amount of eccentricity and the shape variation using the approximated curve. Specifically, the specifying unit 44 specifies the amount of eccentricity and the shape variation using the cosine curve approximated by the approximation unit 43.

[0051] Specifically, the determination unit 44 determines the amount of eccentricity using the cosine curve of equation (2). The determination unit 44 determines the amount of eccentricity as the amplitude and initial phase in equation (2). Therefore, the amount of eccentricity is (R, ξ). Equation (2) is expressed as a distribution of deviations (difference amounts) of the distance CL at each rotation angle from the average value. Therefore, the determination unit 44 assumes that the ideal rotation state of the object 2 is when the distance CL at each rotation angle is the average value (constant), and determines the deviation of the center of rotation from this ideal state as the amount of eccentricity (R, ξ). By determining the amount of eccentricity, the magnitude and direction of the deviation can be determined. By determining the amount of eccentricity, it is possible to correct, for example, the position (center of rotation) of the object 2.

[0052] The determination unit 44 also determines the shape variation using equation (2). Specifically, the determination unit 44 calculates a value by subtracting the value indicated by the cosine curve corresponding to the rotation angle from the difference amount for that rotation angle. That is, the determination unit 44 subtracts the value indicated by equation (2) from the difference amount for each rotation angle. The determination unit 44 then determines the subtracted value as the amount of shape variation (variation amount) corresponding to the rotation angle.

[0053] FIG. 7 is a diagram showing an example of the distribution of the amount of variation with respect to the rotation angle. In FIG. 7, the vertical axis represents the amount of variation and the horizontal axis represents the rotation angle. In FIG. 7, the distribution of the amount of variation is indicated as L4. In this manner, the determination unit 44 calculates the amount of variation corresponding to each rotation angle. By determining the amount of variation, it is possible to indicate the state of variation corresponding to the position of the rotation angle relative to the ideal shape (cylindrical shape) of the target object 2.

[0054] In this manner, the estimation unit 33 identifies the amount of eccentricity and the shape variation.

[0055] <Processing flow> 8 is a flowchart showing an example of the processing flow according to this embodiment. Each of the following steps is executed after X-rays are irradiated onto the object 2 at each rotation angle and a diffraction ring is obtained. Note that the order and content of each of the following steps can be changed as appropriate.

[0056] As an example, a case will be described in which 360 rotation angles are set in 1-degree increments between 0 and 359 degrees. Each rotation angle is associated with a number N (0 to 359). The initial value of the number N is 0, and 359 is the maximum value Nmax.

[0057] (Step SP10) The acquisition unit 31 sets the rotation angle number N to an initial value (0), and the process then proceeds to step SP11.

[0058] (Step SP11) The acquisition unit 31 acquires the diffraction ring corresponding to the rotation angle of number N. Then, the process proceeds to step SP12.

[0059] (Step SP12) The calculation unit 32 calculates the peak position r from the obtained diffraction profile of the diffraction ring, and then the process proceeds to step SP13.

[0060] (Step SP13) The calculation unit 32 calculates the distance CL using the peak position r, and the process then proceeds to step SP14.

[0061] (Step SP14) The acquisition unit 31 determines whether the number N is the maximum value Nmax. If the number N is not the maximum value Nmax, the process proceeds to step SP15. If the number N is the maximum value Nmax, the process proceeds to step SP16.

[0062] (Step SP15) The acquisition unit 31 adds 1 to the rotation angle number N. Then, the process returns to step SP11 and is executed again.

[0063] (Step SP16) The averaging unit 41 calculates the average value of the distances CL corresponding to each rotation angle. That is, the average value of the distances CL calculated corresponding to each of the 360 ​​rotation angles is calculated. Then, the process proceeds to step SP17.

[0064] (Step SP17) The subtraction unit 42 calculates the difference between the distance CL and the average value for each rotation angle, and then the process proceeds to step SP18.

[0065] (Step SP18) The approximation unit 43 approximates the distribution of the difference amount with respect to the rotation angle using a cosine wave curve, and the process then proceeds to step SP19.

[0066] (Step SP19) The determination unit 44 determines the amount of eccentricity using the approximated cosine curve, and the process then proceeds to step SP20.

[0067] (Step SP20) The specifying unit 44 calculates, as the amount of variation, a value obtained by subtracting the value indicated by the cosine curve corresponding to the rotation angle from the difference amount for the rotation angle.

[0068] The eccentricity and shape variation are calculated as described above. The calculated results are displayed on a display device, for example, and provided to the user.

[0069] In the above example, the estimation unit 33 estimates the amount of eccentricity and shape variation. However, the estimation unit 33 may be configured to perform other analyses on the object 2. For example, the estimation unit 33 may be configured to estimate the stress (stress distribution) and half-width (hardness) in the object 2. For example, after calculating the distance CL in step SP13, stress calculation may be performed using a diffraction ring. Note that the specific calculation method is not limited. In other words, stress, the amount of eccentricity, and shape variation can be analyzed from the diffraction ring.

[0070] <Action and effect> As described above, in this embodiment, the X-ray measuring device 1 is an X-ray measuring device 1 that measures the object 2 using X-rays, and includes an acquisition unit 31 that irradiates X-rays onto the object 2 and acquires diffraction rings detected on the detection surface corresponding to each of a plurality of rotation angles when the object 2 is rotated, a calculation unit 32 that calculates the distance CL between the detection surface and the object 2 using the diffraction ring corresponding to each of the plurality of rotation angles, and an estimation unit 33 that estimates at least one of the amount of eccentricity of the object 2 and the variation in the surface shape of the object 2 in the rotation direction based on the distance CL corresponding to each of the rotation angles.

[0071] According to this configuration, the amount of eccentricity and shape variation of the object 2 can be estimated using the diffraction ring obtained by irradiating it with X-rays. In other words, the state of the object 2 can be measured without contact. Furthermore, because X-rays are irradiated onto the object 2, they are less susceptible to the influence of the surface state (e.g., gloss) of the object 2 compared to, for example, a laser. Therefore, it is possible to suppress a decrease in measurement accuracy due to the influence of the surface of the object 2. Furthermore, because a diffraction ring corresponding to the object 2 is obtained, it is also possible to process other analyses, such as stress, in parallel.

[0072] In the X-ray measurement device 1 according to this embodiment, the object 2 has a cylindrical shape.

[0073] According to this configuration, when the target object 2 has a cylindrical shape, the amount of eccentricity and shape variation can be estimated more accurately.

[0074] Furthermore, in the X-ray measuring device 1 according to this embodiment, the estimation unit 33 includes an averaging unit 41 that calculates the average value of the distance CL corresponding to each rotation angle, a subtraction unit 42 that calculates the difference between the distance CL and the average value, an approximation unit 43 that approximates the distribution of the difference amount with respect to the rotation angle using a sine wave or cosine wave curve, and an identification unit 44 that identifies at least one of the eccentricity amount and the variation using the approximated curve.

[0075] According to this configuration, it is possible to identify the amount of decentering and shape variations using the diffraction ring.

[0076] Furthermore, in the X-ray measurement apparatus 1 according to this embodiment, the specifying unit 44 determines the amplitude and initial phase of the approximated curve as the amount of eccentricity.

[0077] According to this configuration, the amount of eccentricity can be determined by approximating a curve (for example, a cosine curve).

[0078] Furthermore, in the X-ray measurement apparatus 1 according to this embodiment, the identifying unit 44 determines the amount of variation corresponding to a rotation angle to be the value obtained by subtracting the value of the curve corresponding to the rotation angle from the difference amount for that rotation angle.

[0079] According to this configuration, the influence of eccentricity can be suppressed and shape variations can be identified.

[0080] <Modification> The present invention is not limited to the above-described embodiments. In other words, designs that are produced by those skilled in the art with appropriate design modifications to the above-described specific examples are also included within the scope of the present invention as long as they include the features of the present invention. Furthermore, the elements of the above-described embodiments and the following modifications can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

[0081] For example, in the above embodiment, the target object 2 has been described as a cylindrical object, but the shape of the target object 2 is not limited to a cylindrical shape.

[0082] Furthermore, in the above embodiment, the processing unit 15 is described as being provided separately from the main body unit 10, but the processing unit 15 is not limited to being provided separately from the main body unit 10, and may be mounted on the main body unit 10.

[0083] Furthermore, the rotation of the rotating unit 17 may be controlled by the processing unit 15, or may be rotated manually by the user. That is, the rotating unit 17 may be controlled by the processing unit 15 so as to have a predetermined rotation angle, or the user may perform alignment so as to have a predetermined rotation angle. [Explanation of symbols]

[0084] 1:X-ray measuring device 2: Object 14: Detection section (detection surface) 31: Acquisition part 32: Calculation section 33: Estimation part CL: Distance

Claims

1. An X-ray measurement device that measures an object using X-rays, an acquisition unit that irradiates the object with X-rays and acquires diffraction rings detected on a detection surface corresponding to each of a plurality of rotation angles when the object is rotated; a calculation unit that calculates a distance between the detection surface and the object using the diffraction ring in correspondence with each of the plurality of rotation angles; an estimation unit that estimates at least one of an amount of eccentricity of the object and a variation in the surface shape of the object in a rotation direction based on the distances corresponding to the respective rotation angles; An X-ray measurement device comprising:

2. The object is cylindrical. The X-ray measurement device according to claim 1 .

3. The estimation unit an averaging unit that calculates an average value of the distances corresponding to each of the rotation angles; a subtraction unit that calculates a difference between the distance and the average value; an approximation unit that approximates the distribution of the difference amount with respect to the rotation angle by a sine wave or cosine wave curve; an identifying unit that identifies at least one of the eccentricity amount and the variation based on the approximated curve; Equipped with The X-ray measurement device according to claim 2 .

4. the specifying unit determines the amplitude and initial phase of the approximated curve as the eccentricity amount. The X-ray measurement device according to claim 3 .

5. the specifying unit determines a value obtained by subtracting the value of the curve corresponding to the rotation angle from the difference amount for the rotation angle as the amount of variation corresponding to the rotation angle.

5. The X-ray measuring device according to claim 3 or 4.

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