JP2011232102A - Shape measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape measurement device which reduces the measurement error of three dimensional shape caused by vibration.SOLUTION: The shape measurement device includes: a probe which lights and images an object to be measured; a linear motor 17 which relatively displaces the probe and the object to be measured; a shape operation part 34 which measures the shape of the object to be measured based on the state of lighting and that of imaging; a deflection detection part 28 which detects the deflection of the probe; and a control part 30 which controls measurement based on the deflection detected by the deflection detection part 28.

Description

  The present invention relates to a shape measuring apparatus for measuring a three-dimensional shape of an object to be measured.

  Conventionally, a method using a laser range finder is known as a method for measuring the three-dimensional shape of an object to be measured (see, for example, Patent Document 1). In this method, the surface of the object to be measured is irradiated with laser light, the object to be measured is observed from a direction different from the irradiation direction, and the three-dimensional shape of the object to be measured which is irradiated with the laser light is obtained according to the principle of triangulation. Is. In this method, the three-dimensional shape of the entire object to be measured can be obtained by scanning the object with the laser beam.

JP 2003-344045 A

  Furthermore, the surface of the measurement object is scanned and irradiated with sheet-like light, and the line light that appears on the measurement object from a direction different from the irradiation direction is imaged by a two-dimensional imaging device. A method for measuring the three-dimensional shape is also known. However, when performing scanning irradiation, if vibration is applied to the measuring device from the outside, the sheet-like light deviates from a predetermined irradiation angle, and an error occurs in the measured three-dimensional shape.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a shape measuring apparatus in which a measurement error of a three-dimensional shape due to the influence of vibration is reduced.

  In order to achieve such an object, the shape measuring apparatus according to the present invention includes an illumination unit that illuminates a measurement object, an imaging unit that images the measurement object illuminated by the illumination unit, the illumination unit, and the illumination unit. Detects at least one shake of the illumination unit and the imaging unit, a relative movement unit that relatively moves the measurement object, a measurement unit that measures the shape of the measurement object from the illumination state and the imaging state, And a control unit that controls the measurement based on the shake detected by the shake detection unit.

  In the above-described invention, it is preferable that the control unit performs control to permit the measurement when the magnitude of the shake detected by the shake detection unit is near zero.

  In the above-described invention, the control unit may perform control to permit the measurement when the magnitude of the shake detected by the shake detection unit is near the maximum.

  In the above invention, the shake detection unit includes at least one of an angular velocity detector that detects an angular velocity of the illumination unit or the imaging unit and an acceleration detector that detects acceleration of the illumination unit or the imaging unit. Preferably, the shake is detected based on at least one of the angular velocity and the acceleration.

  According to the present invention, it is possible to reduce a measurement error of a three-dimensional shape even if vibration is applied to the measurement apparatus.

It is a general view of a shape measuring apparatus. It is a control block diagram of a shape measuring apparatus. It is an enlarged view of the attaching part and probe of 1st Embodiment. It is the schematic of an illumination part and an imaging part. It is a flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 1st Embodiment. It is a figure which shows the modification in the shape measuring apparatus of 1st Embodiment. It is a flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 2nd Embodiment. It is an enlarged view of the attachment part and probe of 3rd Embodiment. It is an enlarged view of a rotation correction mechanism. It is a flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 3rd Embodiment. It is a 1st flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 4th Embodiment. It is a 2nd flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 4th Embodiment. It is a 3rd flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 4th Embodiment. It is a 4th flowchart which shows the procedure of the three-dimensional shape measurement using the shape measuring apparatus of 4th Embodiment. It is the schematic which shows the modification of the illumination part in 3rd Embodiment and 4th Embodiment. It is a schematic diagram which shows an example of the illumination correction in the modification of an illumination part. It is a figure which shows an example of the optical system which satisfied the conditions of Shineproof.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. A shape measuring apparatus according to the first embodiment is shown in FIG. 1, and this shape measuring apparatus 1 measures a shape of a measurement object 5 placed on the stage 6 that supports the measurement object 5 and the stage 6. The shape measuring unit 10 that performs measurement, the control unit 30 that calculates the shape information related to the object 5 to be measured based on the angle information and the measurement information output from the shape measuring unit 10, and the shape information calculated by the control unit 30 is, for example, 3 And a display unit 40 that outputs a dimensional image. Even if the object to be measured 5 is not placed on the stage 6, the shape of the object to be measured 5 can be measured as long as it is within the operating range of the shape measuring unit 10.

  The shape measuring unit 10 includes a base 11, a plurality of arm portions 12 a to 12 e and joint portions (connecting portions) 13 a to 13 f, and a multi-joint structure moving mechanism portion whose base end portion is attached to the base 11. 15 and a probe 20 that is detachably attached to the distal end portion of the moving mechanism portion 15 (the distal end portion of the distal end arm portion 12e) via the attachment portion 16. The moving mechanism unit 15 includes a proximal end arm portion 12a, a first intermediate arm portion 12b, a second intermediate arm portion 12c, a third intermediate arm portion 12d, and a distal end arm portion 12e in this order from the proximal end side. And the 1st-6th joint parts 13a-13f are provided in the edge part of each arm part 12a-12e, respectively.

  The first joint portion 13 a connects the base end portion of the base end arm portion 12 a and the base 11, and the base end arm portion 12 a is rotatable about an axis extending in a substantially vertical direction with respect to the base 11. Composed. The second joint portion 13b connects the distal end portion of the proximal end arm portion 12a and the proximal end portion of the first intermediate arm portion 12b, and the other of the proximal end arm portion 12a and the first intermediate arm portion 12b. Is configured to be able to swing (rotate). The third joint portion 13c connects the distal end portion of the first intermediate arm portion 12b and the proximal end portion of the second intermediate arm portion 12c, and is connected to one of the first intermediate arm portion 12b and the second intermediate arm portion 12c. The other is configured to be able to swing (rotate).

  The fourth joint portion 13d connects the distal end portion of the second intermediate arm portion 12c and the proximal end portion of the third intermediate arm portion 12d, and is connected to one of the second intermediate arm portion 12c and the third intermediate arm portion 12d. The other is configured to be able to swing (rotate). The fifth joint portion 13e connects the distal end portion of the third intermediate arm portion 12d and the proximal end portion of the distal end arm portion 12e, and the other swings with respect to one of the third intermediate arm portion 12d and the distal end arm portion 12e. It can be moved (rotated). The sixth joint portion 13f connects the distal end portion of the distal end arm portion 12e and the attachment portion 16 of the probe 20, and the probe 20 attached to the attachment portion 16 can swing (rotate) with respect to the distal end arm portion 12e. In addition, it is configured to be rotatable about an axis extending in parallel with the tip arm portion 12e. It should be noted that the rotation axes of the second to fifth joint portions 13b to 13e are parallel to each other so that the intermediate arm portions and the tip arm portions 12b to 12e can swing in the same plane (substantially in the vertical plane). It extends in a substantially horizontal direction.

  The rotation shafts of the first to sixth joint portions 13a to 13f are respectively positioned on the distal end side of the joint portions 13a to 13f and the arm portion or the base 11 located on the proximal end side of the joint portions 13a to 13f. In order to detect an angle formed by the arm portion or the probe 20 to be performed, an encoder 31 for measuring the rotation amount of the rotation shaft of each joint portion 13a to 13f is attached. The measured values (hereinafter referred to as “angle information”) by these encoders 31 are output from each encoder 31 to the control unit 30 as shown in FIG. In addition, the first to sixth joint portions 13a to 13f respectively swing the arm portion or probe 20 located on the distal end side with respect to the arm portion or base 11 located on the proximal end side of each joint portion 13a to 13f. A lock mechanism 14 that is moved (rotated) and fixed (locked) at a predetermined position is provided. The operation control of these lock mechanisms 14 is performed by the control unit 30.

  The mounting portion 16 holds the probe 20 by a linear motor 17 (see FIG. 2) so as to be slidable in a direction substantially perpendicular to a direction in which illumination light (line light described later) spreads. That is, the slide movement direction of the probe 20 attached and held on the attachment portion 16 is configured to be the scan direction. The operation control of the linear motor 17 provided in the attachment portion 16 is performed by the control portion 30. An encoder (not shown) is built in the linear motor 17, and a measurement value obtained by the encoder is transmitted from the linear motor 17 (encoder) to the control unit as displacement information of the probe 20 according to the operation of the linear motor 17. 30. In this embodiment, the slide movement direction (scan direction) of the probe 20 is the X direction, the optical axis direction of the probe 20 (illuminating unit 21) and the direction perpendicular to the X direction are the Y direction, and the X direction and the Y direction are perpendicular. May be referred to as the Z direction (see FIG. 1).

  As shown in FIG. 3, the probe 20 includes an illumination unit 21 that illuminates the measurement object 5, an imaging unit 25 that images the measurement object 5 illuminated by the illumination unit 21, and a probe due to the influence of external vibration. 20 (i.e., the illumination unit 21 and the imaging unit 25) and a shake detection unit 28 that detects the shake of the imaging unit 25. Note that the shake detection unit 28 is configured to detect shakes in the X direction, the Y direction, and the Z direction. Further, as shown in FIG. 1, a measurement switch 29 is provided on the side of the probe 20 to perform an operation for instructing the control unit 30 to start and stop shape measurement on the object to be measured 5.

  As shown in FIG. 4, the illumination unit 21 includes a light source 22 such as an LED, a pattern formation unit 23 that forms an illumination pattern, and a projection lens that projects the illumination pattern formed on the pattern formation unit 23 onto the object to be measured 5. 24. The pattern forming unit 23 is composed of a liquid crystal display element or the like, and in the present embodiment, forms an illumination pattern so that illumination light having a cross section in a line shape (hereinafter referred to as line light) is obtained. Therefore, the light emitted from the light source 22 becomes line light when passing through the pattern forming unit 23, and this line light is irradiated (projected) onto the object to be measured 5 on the stage 6 by the projection lens 24.

  As shown in FIG. 4, the imaging unit 25 forms an image with an imaging optical system 26 that forms an image of line light (hereinafter referred to as a line image) irradiated on the object 5 to be measured, and the imaging optical system 26. And an image pickup device 27 for picking up a line image. The image sensor 27 photoelectrically converts a line image formed on the imaging surface to generate an image signal, and outputs the image information to the shape calculation unit 34. Note that the image plane of the imaging optical system 26 satisfies a so-called Scheinproof condition conjugate with the irradiation direction of the line light to be irradiated. Therefore, a line image can always be sharply formed regardless of the height of the DUT 5.

  As shown in FIG. 3, the shake detection unit 28 includes an angular velocity sensor 28 a that detects the angular velocity of the probe 20 (the illumination unit 21 and the imaging unit 25), and an acceleration sensor 28 b that detects the acceleration of the probe 20. The vibration of the probe 20 is detected based on the angular velocity and acceleration detected by the sensor 28a and the acceleration sensor 28b, respectively. Here, the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) refers to the probe 20 (with respect to the target position (including the direction) when the probe 20 is slid (scanned) at a constant speed (or a constant angular speed). This is a deviation (positional deviation and direction deviation) between the illumination unit 21 and the imaging unit 25).

  The shape measuring device 1 of this embodiment is a shape measuring device that can be installed on a factory line or the like, and the shape measuring device 1 may not be installed on a vibration isolation table (not shown) or the like. In such a case, even when the lock mechanism 14 is operated and the joint portions 13a to 13f are fixed, the probe 20 is shaken with respect to the object 5 to be measured due to the influence of external vibration. When the slider is moved (scanned), the probe 20 (the illumination unit 21 and the imaging unit 25) is displaced from the target position. Further, the same positional deviation (shake) occurs due to the deflection of each of the arm portions 12a to 12e.

  The shake detection unit 28 detects such shake of the probe 20 (the illumination unit 21 and the imaging unit 25). The angular velocity sensor 28a of the shake detection unit 28 detects the angular velocities of the probe 20 with the axes extending in the X direction and the Y direction (hereinafter referred to as X rotation axis and Y rotation axis) as rotation axes. The acceleration sensor 28b detects the acceleration of the probe 20 in the X direction and the Y direction, respectively. Note that the vibration of the probe 20 includes a vibration due to the rotation of the probe 20 and a vibration due to the parallel movement of the probe 20. However, since the probe 20 of the present embodiment is attached to the distal end portion (the distal end portion of the distal arm portion 12e) of the moving mechanism portion 15 having a plurality of arm portions 12a to 12e, the probe 20 shakes due to parallel movement. Is considered to be smaller than the vibration caused by the rotation (oscillation) of the probe 20, and the vibration of the probe 20 can be approximated only to the vibration caused by the rotation of the probe 20. However, since the moving mechanism part 15 has many joint parts, it may act as a parallel link mechanism. That is, the angular velocity may not be detected due to the shake, but the acceleration may be detected. In this case, processing is performed as shake due to parallel movement (parallel shake). Note that shake due to parallel movement (parallel shake) can be processed in the same manner as shake due to rotation (oscillation), assuming that the center of rotation is sufficiently far away.

  Therefore, as shown in FIG. 3, when the rotational speed (vector) of the probe 20 is V, the angular speed of the probe 20 is ω, and the rotational radius (vector) of the probe 20 is r, V = r × ω. Therefore, the shake detection unit 28 can obtain the rotation radius r (and the rotation center) of the probe 20 using the angular velocity ω and the acceleration dV / dt detected by the angular velocity sensor 28a and the acceleration sensor 28b, respectively. At this time, the rotation speed V is obtained by performing integration processing on the acceleration dV / dt detected by the acceleration sensor 28b, and the rotation radius r is obtained from the relational expression r = V / (ω + C). Here, C is a constant or function set so that the radius of rotation r does not diverge. Further, since the rotation angle φ of the probe 20 can be obtained by performing integration processing on the angular velocity ω detected by the angular velocity sensor 28a, the shake detecting unit 28 determines the obtained rotation radius r and rotation angle φ of the probe 20. Can be used to determine the amount of deflection (= r × φ) of the probe 20.

  Since the probe 20 moves in the X direction at the time of scanning, the influence of the scanning of the probe 20 is subtracted from the shake amount obtained using the angular velocity and the acceleration in the X direction with the Y rotation axis of the probe 20 as the rotation axis. This is the amount of deflection of the probe 20 in the X direction. Note that the influence of scanning includes a component in which the translation due to scanning is detected by the angular velocity sensor as a rotation component. This component can be obtained in advance by performing a scanning operation in an environment without vibration. Further, since the scanning direction of the probe 20 is the X direction and there should be no movement due to scanning in the Y direction at the time of scanning, the deflection obtained using the angular velocity about the X rotation axis of the probe 20 and the acceleration in the Y direction. The amount becomes the shake amount of the probe 20 in the Y direction as it is.

  As shown in FIG. 2, the control unit 30 outputs a processing unit 32 that controls the shape measurement process of the DUT 5 by the shape measuring apparatus 1, the angle information output from each encoder 31, and the linear motor 17. Using the displacement information (scan amount) obtained, the spatial coordinates and orientation of the probe 20 (coordinates and orientation with a predetermined point in the measurement space as the origin, hereinafter referred to as “position information”) are calculated. Using the position calculation unit 33, the position information output from the position calculation unit 33 and the image information of the line image output from the image sensor 27 (the image of the line light projected onto the measurement object 5), the device under test is used. 5 and a shape calculation unit 34 for calculating shape information (three-dimensional shape). Here, the measurement space refers to a range (space) in which the probe 20 can be moved by the shape measuring apparatus 1 and the space coordinates of the object to be measured 5 can be acquired.

  Moreover, the control part 30 is implement | achieved by the computer, for example, and the process part 32, the position calculating part 33, and the shape calculating part 34 are mounted as a program run with this computer. The output (operation signal) from the measurement switch 29 is input to the processing unit 32, and the operation of the pattern forming unit 23 and the like according to the operation of the measurement switch 29 is controlled by the processing unit 32. Further, the shape information output from the shape calculation unit 34 is stored in, for example, a storage unit 36 provided in the control unit 30, and the shape information is further processed by the processing unit 32 and displayed on the display unit 40. Is output as

  Since the information such as the length of each of the arm portions 12a to 12e is known, the position calculation unit 33 of the control unit 30 is based on the angle information output from each encoder 31, and the base ends of the joint portions 13a to 13f. The angle formed by the arm portion or base 11 positioned on the side and the arm portion or probe 20 positioned on the distal end side of each joint portion 13a to 13f is calculated, and displacement information (from the linear motor 17 (encoder)) ( By adding (scan amount), the three-dimensional coordinates (space coordinates) in the space of the probe 20 can be obtained. Similarly, since the relative positional relationship (relative coordinates) between the illumination unit 21 and the imaging unit 25 in the probe 20 is also known, the shape calculation unit 34 is an imaging unit 25 (imaging element 27) based on the principle of triangulation. By processing the acquired image information (image position information of the line image), the three-dimensional shape of the measurement object 5 within the range that can be imaged by the imaging unit 25 (the measurement object 5 on which the line light is projected). A three-dimensional shape (e.g., expressed as a group of coordinates in this range of discretely represented measurement spaces) can be determined.

  As described above, since the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) may occur, when the shape calculation unit 34 calculates the shape information of the object 5 to be measured, the vibration is detected by the shake detection unit 28. Based on the shake of the probe 20 (the illumination unit 21 and the imaging unit 25), the image information (image position information) of the line image is corrected so as to cancel the shake of the probe 20. At this time, for example, correction is performed so as to cancel the shake amount in the X direction (or Y direction) of the probe 20 with respect to the X direction (or Y direction) coordinate value of the line image on the image. Thereby, it is possible to correct the positional deviation of the line image on the image due to the shake of the probe 20 in the X direction (or Y direction). Thus, even if vibration is applied to the shape measuring apparatus 1, it becomes possible to reduce the measurement error of the three-dimensional shape.

  The three-dimensional shape measurement of the object to be measured 5 using the shape measuring apparatus 1 configured as described above will be described with reference to the flowchart shown in FIG. First, when a predetermined measurement start operation (for example, a push operation) is performed on the measurement switch 29, the angular velocity sensor 28a and the acceleration sensor 28b of the shake detection unit 28 are turned on by the operation control of the processing unit 32 in the control unit 30. Operates (step S101). Next, in order to move to the measurement system, the moving mechanism unit 15 moves the probe 20 to a predetermined measurement start position set in advance by teaching or the like (step S102). At this time, by the operation control of the processing unit 32, the lock mechanism 14 provided in each joint portion 13a to 13f swings (rotates) the arm portion or the probe 20 and fixes (locks) it at a predetermined measurement start position.

  Here, the processing unit 32 determines whether or not a predetermined sensor stabilization time has elapsed since the angular velocity sensor 28a and the acceleration sensor 28b are turned on (step S103), and after the sensor stabilization time has elapsed, Measurement is started by sliding (scanning) the probe 20 with the linear motor 17 (step S104). The sensor stabilization time is the time required for stabilization of vibration of a gyro (not shown) constituting the angular velocity sensor 28a or the acceleration sensor 28b.

  When the measurement is started, the linear motor 17 slides (scans) the probe 20 in the X direction by controlling the operation of the processing unit 32. At this time, displacement information (scan amount) of the probe 20 corresponding to the operation of the linear motor 17 is output from the encoder of the linear motor 17 to the position calculation unit 33 of the control unit 30. At this time, the angular velocity sensor 28a detects the angular velocity of the probe 20 (the illumination unit 21 and the imaging unit 25), the acceleration sensor 28b detects the acceleration of the probe 20, and the shake detection unit 28 includes the angular velocity sensor 28a and the acceleration sensor. Based on the angular velocity and acceleration detected in 28b, the deflection of the probe 20 is calculated as described above and output to the processing unit 32. When the shake detection unit 28 detects the shake of the probe 20, a high-pass filter (not shown) is used to cut noise due to a long-period detection signal shift (so-called drift) between the angular velocity sensor 28 a and the acceleration sensor 28 b. You may make it use.

  When the shake detection unit 28 detects the shake of the probe 20, the processing unit 32 scans the probe 20 from the shake amount of the probe 20 in the X direction (as described above, the shake amount in the X direction obtained using the angular velocity and acceleration). It is determined whether or not the value obtained by subtracting the amount is larger than a predetermined threshold value Th1 (step S105). The predetermined threshold Th1 is the amount of deflection of the probe 20 that starts to affect the calculation result of the shape information (three-dimensional shape) by the shape calculation unit 34. If the determination is No, since the probe 20 is less shaken, the mode is shifted to the stable mode (step S106), and normal measurement without correction according to the shake of the probe 20 is performed. On the other hand, if the determination is Yes, the number N of imaging is set to N = 1 (step S107).

  When the number N of imaging is set to N = 1, the illumination unit 21 irradiates line light (step S108). At this time, the light source 22 is turned on by the operation control of the processing unit 32, and the light emitted from the light source 22 is transmitted through the pattern forming unit 23 to become line light, and the measurement object 5 on the stage 6 by the projection lens 24. Is irradiated (projected).

  An image (line image) of the line light irradiated on the object to be measured 5 is formed on the image pickup surface of the image pickup device 27 by the image pickup optical system 26. Therefore, a line image is captured by the image sensor 27 (step S109). At this time, by the operation control of the processing unit 32, the image sensor 27 photoelectrically converts the line image formed on the imaging surface to generate an image signal, and outputs the image information to the shape calculation unit 34. The shape calculator 34 has a measurement table (not shown) that can record a plurality of pieces of image information in order to calculate the shape information of the DUT 5, and calculates the position along with the image information of the line image. The position information (target position) of the probe 20 at the time of imaging calculated by the unit 33 and the shake of the probe 20 at the time of imaging detected by the shake detection unit 28 are recorded in the measurement table (step S110).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S111). If the determination is No, N = N + 1 is set (step S112), and the process returns to step S108. That is, step S108 to step S110 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown) to obtain the shape information (three-dimensional shape) of the DUT 5. Calculate and finish the process. As described above, when the shape calculation unit 34 calculates the shape information of the DUT 5, based on the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) detected by the shake detection unit 28, The image information (image position information) of the line image is corrected so as to cancel the influence of unintentional shake of the probe 20.

  Thus, according to the first embodiment, even if vibration is applied to the shape measuring apparatus 1, it is possible to reduce the measurement error of the three-dimensional shape. In the first embodiment, the measurement error of the three-dimensional shape can be further reduced by correcting the positional deviation of the line image on the image due to the shake of the probe 20.

  In the first embodiment described above, when the probe 20 is shaken in the X direction due to the influence of external vibration, the probe 20 vibrates in the X direction with respect to the object 5 as shown in FIG. However, since scanning is performed, the density of the imaging positions P is higher than when the probe 20 is not shaken. Therefore, image information at the imaging position P where the shake amount of the probe 20 is larger than a predetermined amount among the plurality of imaging positions P may be excluded from the measurement target. Thereby, since the shape calculation part 34 calculates shape information using the image information with little shake of the probe 20, it can further reduce the measurement error of the three-dimensional shape.

  Further, in the first embodiment described above, the influence of the unintentional shake amount of the probe 20 in the X direction (or Y direction) is canceled with respect to the X direction (or Y direction) coordinate value of the line image on the image. Although the example which performs the correction | amendment which calculates is shown, it is not restricted to this. For example, the shake detection unit 28 detects the shake of the probe 20 in the Z direction, and corrects the X direction coordinate value of the line image on the image so as to cancel the shake amount of the probe 20 in the Z direction. It may be. Thereby, the positional deviation of the line image on the image due to the shake of the probe 20 in the Z direction (the height direction of the DUT 5) can be corrected, and the measurement error of the three-dimensional shape can be further reduced. .

  Here, an example of correcting the image information (image position information) of the line image in the first embodiment will be described with reference to FIGS. 16 and 17. First, the relationship between the coordinates on the image sensor 27 (image plane) and the coordinates on the object (object plane) will be described. As shown in FIG. 17, coordinates on the image plane S3 with the optical axis I as the origin are (H, V), and coordinates on the object plane S1 with the optical axis I as the origin are (h, v). To do. As described above, the image plane of the imaging optical system 26 satisfies the Scheinproof condition. Therefore, as shown in FIG. 17, the distance from the position of the object plane S1 on the optical axis I to the main plane S2 is a, and the distance from the main plane S2 to the position of the image plane S3 on the optical axis I is b. , B / a = β, the inclination of the object plane S1 with respect to the plane perpendicular to the optical axis I is θ, and the inclination of the image plane S3 with respect to the plane perpendicular to the optical axis I is θ ′, the following equation (1) And the condition expressed by the formula (2) is satisfied.

  Next, a change in coordinates on the measurement object 5 due to illumination deviation will be described. As shown in FIG. 16, when the coordinates of the intersection of the optical axis of the illuminating unit 21 and the optical axis of the imaging unit 25 at the scan origin are A (x0, y0, z0), an object plane that satisfies the Scheimpflug condition ( When the coordinates on the YZ plane in the example of FIG. 16 are (h0, v0), the coordinates of the line light on the surface of the object to be measured 5 at this time are a (x0, y0 + h0, z0 + v0). When the probe 20 slides in the X direction by the scan amount Δx, the coordinates of the intersection point of the optical axis of the illumination unit 21 and the optical axis of the imaging unit 25 become B (x0 + Δx, y0, z0). Further, when the coordinates on the object plane are (h1, v1), the coordinates of the line light on the surface of the object to be measured 5 at this time are b (x0 + Δx, y0 + h1, z0 + v1). When the probe 20 slides in the X direction by the scan amount Δx, if the shake due to the rotation of the probe 20 occurs at the rotation radius r by the rotation angle φ, the optical axis of the illumination unit 21 and the optical axis of the imaging unit 25 The coordinates of the intersection point are C (x0 + Δx−r × sinφ, y0, z0 + r × (1−cosφ)). Further, when the coordinates on the object plane are (h2, v2), the coordinates of the line light on the surface of the object to be measured 5 at this time are c (x0 + Δx−r × sinφ, y0 + h2, z0 + r × (1−cosφ) + v2 ×. cosφ).

  The correction of the image position information of the line image, that is, the correction of the coordinates of the line light irradiated on the surface of the object 5 to be measured will be described. Assuming that the coordinates of the line image obtained on the image sensor 27 (image plane) are (H, V), if the shake amount of the probe 20 is larger than a predetermined threshold value Th1, the correction of the image position information of the line image is performed. And the coordinates of the line light on the surface of the measured object 5 after correction can be obtained as (x0 + Δx−r × sinφ, y0 + h, z0 + r × (1−cosφ) + v × cosφ) using the above-mentioned coordinates c. . On the other hand, when the shake amount of the probe 20 described above is equal to or less than the predetermined threshold Th1, the coordinates of the line light on the surface of the object to be measured 5 are calculated using the above-described coordinates b without correcting the image position information of the line image. (X0 + Δx, y0 + h, z0 + v).

  The coordinates (h, v) on the object plane can be obtained from the coordinates (H, V) of the line image using the above-described equations (1) and (2). Here, the parameters b, β, θ ′ in the equations (1) and (2) are known values determined by the optical system. Further, the rotation radius r and the rotation angle φ can be obtained by the shake detection unit 28 as described above. Further, the scan amount Δx can be obtained from the output of the encoder of the linear motor 17.

  Next, a second embodiment of the shape measuring apparatus will be described. The shape measuring apparatus according to the second embodiment has the same configuration as that of the shape measuring apparatus 1 according to the first embodiment except for some processes in the control unit 30, and the same reference numerals as those in the first embodiment are used for each part. The detailed description is omitted.

  Therefore, the three-dimensional shape measurement of the object to be measured 5 using the shape measuring apparatus of the second embodiment will be described with reference to the flowchart shown in FIG. First, when a predetermined measurement start operation (for example, a push operation) is performed on the measurement switch 29, the angular velocity sensor 28a and the acceleration sensor 28b of the shake detection unit 28 are turned on by the operation control of the processing unit 32 in the control unit 30. Operates (step S201). Next, in order to move to the measurement system, the movement mechanism unit 15 moves the probe 20 to a predetermined measurement start position set in advance by teaching or the like, similarly to the case of the first embodiment (step S202).

  Here, the processing unit 32 determines whether or not a predetermined sensor stabilization time has elapsed since the angular velocity sensor 28a and the acceleration sensor 28b are turned on (step S203), and similarly to the case of the first embodiment, After the sensor stabilization time has elapsed, the linear motor 17 slides (scans) the probe 20 to start measurement (step S204).

  When the measurement is started, as in the case of the first embodiment, the processing unit 32 detects the amount of vibration of the probe 20 in the X direction (as described above, from the amount of vibration in the X direction obtained using the angular velocity and acceleration). It is determined whether or not (the amount obtained by subtracting the scan amount) is larger than a predetermined threshold Th2 (step S205). The predetermined threshold Th2 is the amount of deflection of the probe 20 that starts to affect the calculation result of the shape information (three-dimensional shape) by the shape calculation unit 34. If the determination is No, the probe 20 is less shaken so that the stable mode is entered (step S206), and normal measurement is performed without performing correction according to the probe 20 shake. On the other hand, if the determination is Yes, the number N of imaging is set to N = 1 (step S207).

  When the number N of times of imaging is set to N = 1, the processing unit 32 obtains the vibration period of the probe 20 (for example, in the X direction), and the image sensor 27 is a line image when the phase of the vibration of the probe 20 is N × π. Control is performed so as to image (step S208). At this time, the light source 22 is turned on by the operation control of the processing unit 32, and the light emitted from the light source 22 is transmitted through the pattern forming unit 23 to become line light, and the measurement object 5 on the stage 6 by the projection lens 24. Is irradiated (projected).

  Since the image of the line light (line image) irradiated to the object to be measured 5 is imaged on the imaging surface of the imaging element 27 by the imaging optical system 26, the movement of the probe 20 is controlled by controlling the operation of the processing unit 32. When the phase is N × π, the image sensor 27 captures a line image on the imaging surface (step S209). At this time, as in the case of the first embodiment, the image information of the line image output from the imaging device 27 is the positional information (target position) of the probe 20 at the time of imaging calculated by the position calculation unit 33, and the shake. Along with the vibration of the probe 20 at the time of imaging detected by the detector 28, it is recorded in a measurement table (not shown) of the shape calculator 34 (step S210).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S211). If the determination is No, N = N + 1 is set (step S212), and the process returns to step S208. That is, step S208 to step S210 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown) to obtain the shape information (three-dimensional shape) of the DUT 5. Calculate and finish the process. In the present embodiment, since control is performed so that the image pickup device 27 captures a line image when the phase of the shake of the probe 20 is N × π, if the shake of the probe 20 in the initial phase is zero, the probe 20 The image sensor 27 captures a line image at a phase timing at which the fluctuation of the image becomes zero. Therefore, when the shape calculation unit 34 calculates the shape information of the DUT 5, it is not necessary to correct the image information (image position information) of the line image. Note that when the phase is N × π is when the magnitude of the shake is small, it may be in a range including N × π.

  Thus, according to the second embodiment, the same effect as in the first embodiment can be obtained. In the second embodiment, the measurement error of the three-dimensional shape can be further reduced by performing control so that the imaging element 27 captures a line image at a phase timing at which the deflection of the probe 20 becomes zero. .

  In the second embodiment described above, the processing unit 32 performs control so that the imaging element 27 captures a line image when the phase of the shake of the probe 20 is N × π. However, the present invention is not limited to this. Instead, in step S208, control may be performed so that the imaging device 27 captures a line image when the phase of the shake of the probe 20 is (N−1 / 2) × π. In this case, if the shake of the probe 20 in the initial phase is zero, the image sensor 27 captures a line image at a phase timing at which the shake (absolute value) of the probe 20 is maximized. For this reason, when the shape calculation unit 34 calculates the shape information of the DUT 5, it is necessary to correct the image information (image position information) of the line image, but the shake (absolute value) of the probe 20 is maximized. In some cases, imaging can be performed in a state where there is no speed change due to the shake of the probe 20, and a clearer line image can be captured, so that measurement errors of the three-dimensional shape can be further reduced.

  Next, a third embodiment of the shape measuring apparatus will be described. The shape measuring apparatus according to the third embodiment has the same configuration as that of the shape measuring apparatus 1 according to the first embodiment except for the configuration of the mounting portion and a part of the processing in the control unit 30, and each part has the same configuration as that of the first embodiment. The same reference numerals as those in the case are attached and detailed description is omitted. As shown in FIG. 8, the mounting portion 50 of the third embodiment includes a rotation correction mechanism 60 that can detachably hold the probe 20 and correct the orientation of the probe 20 by rotation, and the Y direction of the probe 20 by translation. And a Y parallel correction mechanism 80 that can correct the position of the X axis, and an X parallel correction mechanism 90 that can correct the position of the probe 20 in the X direction by parallel movement. The probe 20 is held so as to be slidable (scanned) in the X direction (not shown).

  In the third embodiment, a description will be given of a mode in which the probe 20 is driven so as to cancel the shake of the probe 20 based on the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) detected by the shake detection unit 28. To do. By the way, when the rotation radius of the vibration of the probe 20 is large and the vibration is small, it can be approximated to the vibration due to the parallel movement of the probe 20, so that the vibration of the probe 20 can be corrected only by moving the probe 20 in parallel. is there. However, as described above, the vibration of the probe 20 includes a vibration due to the parallel movement of the probe 20 and a vibration due to the rotation of the probe 20. For this reason, when the deflection of the probe 20 increases, the deflection of the probe 20 cannot be corrected only by moving the probe 20 in parallel. Therefore, the mounting portion 50 of the third embodiment includes the rotation correction mechanism 60 in addition to the X parallel correction mechanism 90 and the Y parallel correction mechanism 80 as described above.

  As shown in FIG. 9, the rotation correction mechanism 60 includes a probe holder 61 that detachably holds the probe 20 and an X rotation support portion that rotatably supports the probe holder 61 with an axis extending in the X direction as a rotation axis. 65, and a Y rotation support portion 70 that rotatably supports the X rotation support portion 65 with an axis extending in the Y direction as a rotation axis. The probe holding part 61 is formed in a substantially spherical shape having a flat part at the tip. A holding hole 62 for holding the probe 20 is formed at the distal end portion of the probe holding portion 61. For example, an engagement protrusion (not shown) formed at the proximal end portion of the probe 20 is formed in the holding hole. By engaging with 62, the probe 20 is detachably attached to and held by the probe holding portion 61.

  The X rotation support portion 65 includes a frame member 67 that rotatably supports the probe holding portion 61 and an X rotation motor 68 that rotationally drives the probe holding portion 61. The frame member 67 rotatably supports the probe holding portion 61 positioned inside the frame member 67 with the central axis Ax of the rotation shaft 66 as a rotation axis via the rotation shaft 66 extending in the X direction. The X rotation motor 68 is, for example, a servo motor with a built-in encoder. The X rotation motor 68 rotates the probe holding unit 61 about the central axis Ax of the rotation shaft 66 as a rotation axis, and the rotation angle of the probe holding unit 61 at this time, that is, The rotation angle with the axis extending in the X direction of the probe 20 as the rotation axis is detected.

  The Y rotation support unit 70 includes a pair of left and right brackets 72a and 72b that rotatably support the X rotation support unit 65 together with the probe holding unit 61, a plate-like base plate 73 that supports the brackets 72a and 72b, and an X rotation support. And a Y-rotation motor 74 that rotationally drives the portion 65. The pair of left and right brackets 72a and 72b rotatably supports the X rotation support portion 65 about the central axis Ay of the rotation shaft 71 via the rotation shaft 71 extending in the Y direction. The base plate 73 is attached to the Y parallel correction mechanism 80 in a state of supporting the brackets 72a and 72b. The Y rotation motor 74 is, for example, a servo motor with a built-in encoder, and rotationally drives the X rotation support portion 65 with the central axis Ay of the rotation shaft 71 as a rotation axis, and the rotation angle of the X rotation support portion 65 at this time That is, the rotation angle with the axis extending in the Y direction of the probe 20 as the rotation axis is detected.

  As a result, the rotation correction mechanism 60 holds the probe 20 so as to be rotatable about the axis extending in the XY direction as a rotation axis, and can correct the shake due to the rotation of the probe 20. The operation control of the X rotation motor 68 and the Y rotation motor 74 is performed by the control unit 30. In addition, the measurement values obtained by the encoders built in the X rotation motor 68 and the Y rotation motor 74 are output to the control unit 30 from each motor (encoder).

  As shown in FIG. 8, the Y parallel correction mechanism 80 includes a first holding plate 81, a pair of left and right Y direction linear guides 82 a and 82 b that are attached to the first holding plate 81 and extend in the Y direction, and a rotation correction mechanism 60. And a Y-direction linear motor 83 that drives the motor in the Y direction. The first holding plate 81 is formed in a plate shape that is bent substantially at a right angle, and is arranged so that its bottom portion extends in the Y direction and its side portion extends in the Z direction. The pair of left and right Y-direction linear guides 82a and 82b are attached in parallel to the wall portion of the first holding plate 81, and hold the rotation correction mechanism 60 so as to be slidable (translatable) in the Y direction. The Y-direction linear motor 83 is attached to the bottom of the first holding plate 81 so as to extend in the Y direction, and drives the rotation correction mechanism 60 in the Y direction along the Y-direction linear guides 82a and 82b.

  Thereby, the Y parallel correction mechanism 80 can correct the shake due to the parallel movement of the probe 20 held in the rotation correction mechanism 60 in the Y direction. The operation control of the Y-direction linear motor 83 is performed by the control unit 30. An encoder (not shown) is built in the Y-direction linear motor 83, and a measurement value by this encoder is output from the Y-direction linear motor 83 (encoder) to the control unit 30.

  The X parallel correction mechanism 90 drives the Y parallel correction mechanism 80 in the X direction together with the second holding plate 91, the X direction linear guide 92 attached to the second holding plate 91 and extending in the X direction, and the rotation correction mechanism 60. And an X-direction linear motor (not shown). The first holding plate 81 is formed in a plate shape that is bent substantially at a right angle, and is arranged so that its bottom portion extends in the Y direction and its side portion extends in the Z direction. The second holding plate 91 is disposed so as to overlap the first holding plate 81. The length of the second holding plate 91 in the X direction can be slid (scanned) in the X direction by the Y parallel correction mechanism 80. Thus, it is longer than the first holding plate 81. The X-direction linear guide 92 is attached to the bottom of the second holding plate 91, and holds the Y parallel correction mechanism 80 so as to be slidable (parallel) in the X direction. An X-direction linear motor (not shown) is attached to the bottom of the second holding plate 91 so as to extend in the X direction, and drives the Y parallel correction mechanism 80 in the X direction along the X-direction linear guide 92.

  As a result, the X parallel correction mechanism 90 can slide (scan) the probe 20 held by the rotation correction mechanism 60 in the X direction, and can correct the shake caused by the parallel movement of the probe 20 in the X direction. . The operation control of the X-direction linear motor (not shown) is performed by the control unit 30. The X-direction linear motor includes an encoder (not shown), and the measured value by the encoder is output from the X-direction linear motor (encoder) to the control unit 30.

  The three-dimensional shape measurement of the object to be measured 5 using the shape measuring apparatus of the third embodiment will be described with reference to the flowchart shown in FIG. First, when a predetermined measurement start operation (for example, a push operation) is performed on the measurement switch 29, the angular velocity sensor 28a and the acceleration sensor 28b of the shake detection unit 28 are turned on by the operation control of the processing unit 32 in the control unit 30. Operates (step S301). Next, in order to move to the measurement system, the moving mechanism unit 15 moves the probe 20 to a predetermined measurement start position set in advance by teaching or the like, similarly to the case of the first embodiment (step S302).

  Here, the processing unit 32 determines whether or not a predetermined sensor stabilization time has elapsed since the angular velocity sensor 28a and the acceleration sensor 28b are turned on (step S303), and as in the case of the first embodiment, After the sensor stabilization time has elapsed, the probe 20 is slid (scanned) by an X-direction linear motor (not shown) of the X parallel correction mechanism 90 to start measurement (step S304).

  When the measurement is started, as in the case of the first embodiment, the processing unit 32 detects the amount of vibration of the probe 20 in the X direction (as described above, from the amount of vibration in the X direction obtained using the angular velocity and acceleration). It is determined whether or not (the amount obtained by subtracting the scan amount) is larger than a predetermined threshold value Th3 (step S305). The predetermined threshold Th3 is the amount of deflection of the probe 20 that starts to affect the calculation result of the shape information (three-dimensional shape) by the shape calculation unit 34. If the determination is No, since the probe 20 is less shaken, the stable mode is entered (step S306), and normal measurement is performed without performing correction according to the shake of the probe 20. On the other hand, if the determination is Yes, the number N of imaging is set to N = 1 (step S307).

  When the number N of times of imaging is set to N = 1, the processing unit 32 performs illumination by the illumination unit 21, and based on the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) detected by the shake detection unit 28, Control is performed to drive the probe 20 so as to cancel the shake of the probe 20 (step S308). At this time, the rotation correction mechanism 60, the Y parallel correction mechanism 80, and the X parallel correction mechanism 90 are controlled based on the shake of the probe 20 detected by the shake detection unit 28 by the operation control of the processing unit 32. The probe 20 is rotated or translated so as to cancel out the shake, and the irradiation position of the line light by the illumination unit 21 is corrected, and the imaging position by the imaging unit 25 is corrected so that the relative position to the illumination unit 21 does not change.

  As described above, the rotation correction mechanism 60 corrects shake due to rotation of the probe 20, and the Y parallel correction mechanism 80 corrects shake due to translation of the probe 20 in the Y direction. Further, the X parallel correction mechanism 90 corrects the shake due to the parallel movement of the probe 20 in the X direction while sliding (scanning) the probe 20 in the X direction. The light source 22 is turned on by the operation control of the processing unit 32 in a state where the irradiation position of the line light by the illumination unit 21 is corrected in this way, and the light emitted from the light source 22 is transmitted through the pattern forming unit 23 to the line. It becomes light and is irradiated (projected) onto the object 5 to be measured on the stage 6 by the projection lens 24.

  Since the image (line image) of the line light irradiated to the object to be measured 5 is formed on the image pickup surface of the image pickup device 27 by the image pickup optical system 26, the image pickup device 27 is picked up by the operation control of the processing unit 32. A line image on the surface is captured (step S309). At this time, as in the case of the first embodiment, the image information of the line image output from the imaging device 27 is the positional information (target position) of the probe 20 at the time of imaging calculated by the position calculation unit 33, and the shake. Along with the vibration of the probe 20 at the time of imaging detected by the detector 28, it is recorded in a measurement table (not shown) of the shape calculator 34 (step S310).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S311). If the determination is No, N = N + 1 is set (step S312), and the process returns to step S308. That is, step S308 to step S310 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown) to obtain the shape information (three-dimensional shape) of the DUT 5. Calculate and finish the process. In this embodiment, since the probe 20 is rotated or translated so as to cancel the shake of the probe 20 and the irradiation position of the line light by the illumination unit 21 is corrected, all the shake of the probe 20 is corrected by the correction. If it is possible to cancel, it is not necessary to correct the image information (image position information) of the line image as described in the first embodiment when the shape calculation unit 34 calculates the shape information of the DUT 5.

  Thus, according to the third embodiment, the same effect as in the first embodiment can be obtained. In the third embodiment, the probe 20 (the illumination unit 21 and the imaging unit 25) is driven to correct the positional deviation of the line light (illumination light) due to the shake of the probe 20, thereby measuring the three-dimensional shape measurement error. Can be further reduced.

  Next, a fourth embodiment of the shape measuring apparatus will be described. The shape measuring device of the fourth embodiment is the same configuration as the shape measuring device 1 of the first embodiment except for the configuration of the mounting portion and part of the processing in the control unit 30, and the configuration of the mounting portion is Since it is the same structure as the attachment part 50 of 3rd Embodiment, the code | symbol same as the case of 1st Embodiment (except an attachment part) and 3rd Embodiment is attached | subjected to each part, and detailed description is abbreviate | omitted.

  In the fourth embodiment, correction of the image information (image position information) of the line image by the shape calculation unit 34 described in the first embodiment and the irradiation position of the line light by driving the probe 20 described in the third embodiment. A mode in which correction is combined will be described. In this embodiment, the correction of the image information (image position information) of the line image by the shape calculation unit 34 described in the first embodiment is referred to as passive correction, and the line by driving the probe 20 described in the third embodiment. The correction of the light irradiation position is referred to as active correction.

  Therefore, the three-dimensional shape measurement of the DUT 5 using the shape measuring apparatus according to the fourth embodiment will be described with reference to the flowcharts shown in FIGS. First, as shown in FIG. 11, when a predetermined measurement start operation (for example, a push operation) is performed on the measurement switch 29, the angular velocity sensor of the shake detection unit 28 is controlled by the operation control of the processing unit 32 in the control unit 30. 28a and the acceleration sensor 28b are turned on (step S401). Next, in order to move to the measurement system, the moving mechanism unit 15 moves the probe 20 to a predetermined measurement start position set in advance by teaching or the like, similarly to the case of the first embodiment (step S402).

  Here, the processing unit 32 determines whether or not a predetermined sensor stabilization time has elapsed since the angular velocity sensor 28a and the acceleration sensor 28b are turned on (step S403), and similarly to the case of the first embodiment, After the sensor stabilization time has elapsed, the probe 20 is slid (scanned) by an X direction linear motor (not shown) of the X parallel correction mechanism 90 to start measurement (step S404).

  When the measurement is started, as in the case of the first embodiment, the processing unit 32 detects the amount of vibration of the probe 20 in the X direction (as described above, from the amount of vibration in the X direction obtained using the angular velocity and acceleration). It is determined whether or not (the amount obtained by subtracting the scan amount) is greater than a predetermined threshold value Th4 (step S405). If the determination is Yes, the processing unit 32 further determines whether or not the vibration frequency of the probe 20 (the reciprocal of the cycle in which the vibration of the probe 20 occurs) is greater than the predetermined first frequency f1 (step S406).

  If the determination in step S406 is Yes, that is, if the amount of vibration of the probe 20 is greater than the predetermined threshold Th4 and the frequency of vibration of the probe 20 is greater than the predetermined first frequency f1, the processing unit 32 In the subsequent measurement, it is determined to perform both passive correction and active correction (step S410). On the other hand, if the determination in step S406 is No, that is, if the amount of vibration of the probe 20 is larger than the predetermined threshold Th4 and the frequency of vibration of the probe 20 is smaller than the predetermined first frequency f1, the processing unit 32 determines to perform only passive correction in the subsequent measurement (step S420).

  If the determination in step S405 is No, the processing unit 32 similarly determines whether or not the vibration frequency of the probe 20 (the reciprocal of the period in which the vibration of the probe 20 occurs) is greater than the predetermined second frequency f2. Is determined (step S407). If the determination in step S407 is Yes, that is, if the amount of vibration of the probe 20 is smaller than the predetermined threshold Th4 and the frequency of vibration of the probe 20 is larger than the predetermined second frequency f2, the processing unit 32 Then, it is determined that only active correction is performed in the subsequent measurement (step S430). On the other hand, if the determination in step S407 is No, that is, if the amount of vibration of the probe 20 is smaller than the predetermined threshold Th4 and the frequency of vibration of the probe 20 is smaller than the predetermined second frequency f2, the stable mode (Step S408), and normal measurement is performed without performing correction according to the deflection of the probe 20.

  The predetermined threshold Th4 is the amount of deflection of the probe 20 that starts to affect the calculation result of the shape information (three-dimensional shape) by the shape calculation unit 34. The predetermined first frequency f1 is set to a value larger than the imaging frequency (sampling frequency) by the imaging unit 25, for example, and the shake of the probe 20 having a high frequency that cannot be sufficiently corrected by passive correction is corrected by active correction. can do. On the other hand, since the drive amount of the probe 20 by the active correction is limited, the shake of the probe 20 having a large shake amount that cannot be sufficiently corrected by the active correction can be corrected by the passive correction. The predetermined second frequency f2 may be set to the same value as the first frequency f1, or may be set to a value different from the first frequency f1 as necessary.

  When both passive correction and active correction are performed, the number of times of imaging N is set to N = 1 as shown in FIG. 12 (step S411).

  When the number N of imaging is set to N = 1, the processing unit 32 performs illumination by the illumination unit 21 and controls to perform the active correction described in the third embodiment (step S412). At this time, the rotation correction mechanism 60, the Y parallel correction mechanism 80, and the X parallel correction mechanism 90 are controlled based on the shake of the probe 20 detected by the shake detection unit 28 by the operation control of the processing unit 32. The probe 20 is rotated or translated so as to cancel out the shake, and the irradiation position of the line light by the illumination unit 21 is corrected, and the imaging position by the imaging unit 25 is corrected so that the relative position to the illumination unit 21 does not change. The light source 22 is turned on by the operation control of the processing unit 32 in a state where the irradiation position of the line light by the illumination unit 21 is corrected in this way, and the light emitted from the light source 22 is transmitted through the pattern forming unit 23 to the line. It becomes light and is irradiated (projected) onto the object 5 to be measured on the stage 6 by the projection lens 24.

  Since the image (line image) of the line light irradiated to the object to be measured 5 is formed on the image pickup surface of the image pickup device 27 by the image pickup optical system 26, the image pickup device 27 is picked up by the operation control of the processing unit 32. A line image on the surface is captured (step S413). At this time, as in the case of the first embodiment, the image information of the line image output from the imaging device 27 is the positional information (target position) of the probe 20 at the time of imaging calculated by the position calculation unit 33, and the shake. Along with the vibration of the probe 20 at the time of imaging detected by the detection unit 28, it is recorded in a measurement table (not shown) of the shape calculation unit 34 (step S414).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S415). If the determination is No, N = N + 1 is set (step S416), and the process returns to step S412. That is, step S412 to step S414 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown) while performing the passive correction described in the first embodiment. The shape information (three-dimensional shape) of the measurement object 5 is calculated (step S417), and the process ends.

  When only passive correction is performed, as shown in FIG. 13, the imaging count N is set to N = 1 (step S421).

  When the number N of times of imaging is set to N = 1, line illumination is performed by the illumination unit 21 without performing active correction (step S422). At this time, the light source 22 is turned on by the operation control of the processing unit 32, and the light emitted from the light source 22 is transmitted through the pattern forming unit 23 to become line light, and the measurement object 5 on the stage 6 by the projection lens 24. Is irradiated (projected).

  Since the image (line image) of the line light irradiated to the object to be measured 5 is formed on the image pickup surface of the image pickup device 27 by the image pickup optical system 26, the image pickup device 27 is picked up by the operation control of the processing unit 32. A line image on the surface is captured (step S423). At this time, the image information of the line image output from the image sensor 27 includes the position information (target position) of the probe 20 at the time of imaging calculated by the position calculator 33 and the information at the time of imaging detected by the shake detector 28. Along with the deflection of the probe 20, it is recorded in a measurement table (not shown) of the shape calculator 34 (step S424).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S425). If the determination is No, N = N + 1 is set (step S426), and the process returns to step S422. That is, Steps S422 to S424 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown) while performing the passive correction described in the first embodiment. The shape information (three-dimensional shape) of the measurement object 5 is calculated (step S427), and the process ends.

  Further, when only active correction is performed, the number N of imaging is set to N = 1 as shown in FIG. 14 (step S431).

  When the number of times of imaging N is set to N = 1, the processing unit 32 performs illumination by the illumination unit 21 and controls to perform the active correction described in the third embodiment (step S432). At this time, the light source 22 is turned on by the operation control of the processing unit 32 in a state where the irradiation position of the line light by the illumination unit 21 is corrected as described above, and the light emitted from the light source 22 passes through the pattern forming unit 23. The light passes through and becomes line light, and is irradiated (projected) onto the object to be measured 5 on the stage 6 by the projection lens 24.

  Since the image (line image) of the line light irradiated to the object to be measured 5 is formed on the image pickup surface of the image pickup device 27 by the image pickup optical system 26, the image pickup device 27 is picked up by the operation control of the processing unit 32. A line image on the surface is captured (step S433). At this time, the image information of the line image output from the image sensor 27 includes the position information (target position) of the probe 20 at the time of imaging calculated by the position calculator 33 and the information at the time of imaging detected by the shake detector 28. Along with the deflection of the probe 20, it is recorded in a measurement table (not shown) of the shape calculator 34 (step S434).

  If the total number of times of imaging is Ne, the processing unit 32 determines whether N = Ne (step S435). If the determination is No, N = N + 1 is set (step S436), and the process returns to step S432. That is, steps S432 to S434 are repeated until all the images are captured. On the other hand, when the determination is Yes, the shape calculation unit 34 uses the image information and position information of the line image recorded in the measurement table (not shown), and the shape information of the DUT 5 without performing passive correction. (Three-dimensional shape) is calculated (step S437), and the process ends.

  Thus, according to the fourth embodiment, the same effect as in the first embodiment can be obtained. In the fourth embodiment, the measurement error of the three-dimensional shape can be further reduced by selectively using passive correction and active correction as necessary.

  In each of the above-described embodiments, the method for acquiring the shape information of the object 5 to be measured by the probe 20 is not limited to the above-described triangulation method by light cutting, but acquires a bright-field image and measures the shape by computer analysis. Or a method based on triangulation using a stereo image can be used as appropriate.

  In each of the above-described embodiments, the probe 20 (the illumination unit 21 and the imaging unit 25) is slid (scanned) using a linear motor. However, the present invention is not limited to this. For example, a ball screw, a motor, or the like. The probe 20 may be slid (scanned) using a linear motion mechanism using

  In each of the above-described embodiments, when determining whether or not the shake amount of the probe 20 is larger than a predetermined threshold, the scan amount of the probe 20 is subtracted from the shake amount in the X direction detected by the shake detection unit 28. However, if the angular velocity is not detected by the angular velocity sensor 28a when the scanning operation is performed in an environment free from vibration in advance, the shake amount in the X direction detected by the shake detection unit 28 is ( The amount of deflection of the probe 20 can be used as it is without subtracting the scan amount of the probe 20.

  Further, in the above-described third and fourth embodiments, the probe 20 cancels the shake of the probe 20 based on the shake of the probe 20 (the illumination unit 21 and the imaging unit 25) detected by the shake detection unit 28. However, the present invention is not limited to this, and at least a part of the illumination unit 21 or the imaging unit 25 constituting the probe 20 may be driven. For example, as shown in FIG. 15, the illumination unit 121 of the probe extends in a direction perpendicular to the optical axis direction and the longitudinal direction of the cylindrical lens 124, such as a light source 122 such as an LED, a condenser lens 123, and a cylindrical lens 124. A rotation driving unit 125 that rotates the condensing lens 123 about the axis as the rotation axis α may be included. The configuration for driving the entire probe 20 is effective for a large amplitude shake at a relatively slow speed, and the configuration for driving a part of the optical system is for a small amplitude shake at a relatively high speed. It is valid. In addition, the structure remove | excluding the rotational drive part 125 from this illumination part 121 is applicable also to the illumination part of 3rd Embodiment and 4th Embodiment.

  In such an illuminating unit 121, the light emitted from the light source 122 passes through the condenser lens 123 and the cylindrical lens 124 to become sheet-like light (sheet light), and irradiates the object 5 to be measured on the stage 6. Then, a line image appears on the object to be measured 5. At this time, when the condensing lens 123 is rotated around the rotation axis α by the rotation driving unit 125, for example, as shown in FIG. 16, the line image can be rotated about the axis extending in the Y direction as the rotation axis. It is possible to correct the positional deviation (mainly rotational deviation) of the line image (illumination light) due to the fluctuation of the image.

  In this case, offset (positional deviation) may remain in the X direction (scan direction), but by inserting a parallel plane plate (harving: not shown) between the cylindrical lens 124 and the DUT 5. It is possible to eliminate the offset in the X direction by translating the line image in the X direction. If the line image is rotated or translated in this way, the detection angle of the imaging unit 25 (relative angle with respect to the illumination light) changes, and the Scheinproof condition is not satisfied. In this case, it is necessary to drive the optical system of the imaging unit so as to maintain (satisfy) the condition of the shine proof in accordance with the movement of the traveling surface of the line light (synchronously). In addition to maintaining the Scheimpflug condition, it is desirable to maintain the imaging magnification. However, the imaging magnification can be corrected by arithmetic processing. Further, when the shape calculation unit 34 calculates the shape information of the object 5 to be measured, the image information (image position information) of the line image is corrected according to the rotation angle of the condensing lens 123 by the rotation driving unit 125. By doing so, the shape information (three-dimensional shape) of the DUT 5 can be obtained.

  Further, when correcting the shake of the probe 20 by driving a part of the illumination unit 21 or the imaging unit 25, when correcting a shake with a large amplitude, the correction drive range is limited. After the offset, the correction drive may be started so as to perform the running.

DESCRIPTION OF SYMBOLS 1 Shape measuring apparatus 5 Measured object 16 Mounting part (1st Embodiment) 17 Linear motor (relative moving part)
DESCRIPTION OF SYMBOLS 20 Probe 21 Illumination part 25 Image pick-up part 28 Shake detection part 28a Angular velocity sensor (angular velocity detector) 28b Acceleration sensor (acceleration detector)
30 Control Unit 32 Processing Unit 33 Position Calculation Unit 34 Shape Calculation Unit (Measurement Unit)
50 Mounting portion (second embodiment)
60 Rotation Correction Mechanism 80 Y Parallel Correction Mechanism 90 X Parallel Correction Mechanism 121 Illumination Unit (Modification)
125 Rotation drive

Claims (4)

An illumination unit for illuminating the device under test
An imaging unit that images the object to be measured illuminated by the illumination unit;
A relative movement unit for relatively moving the illumination unit and the object to be measured;
A measuring unit for measuring the shape of the object to be measured from the illumination state and the imaging state;
A shake detection unit that detects a shake of at least one of the illumination unit and the imaging unit;
A shape measuring apparatus comprising: a control unit that controls the measurement based on a shake detected by the shake detection unit.   The shape measuring apparatus according to claim 1, wherein the control unit performs control to allow the measurement when the magnitude of the shake detected by the shake detection unit is near zero.   The shape measuring apparatus according to claim 1, wherein the control unit performs control to permit the measurement when the magnitude of the shake detected by the shake detection unit is near a maximum.   The shake detection unit includes at least one of an angular velocity detector that detects an angular velocity of the illumination unit or the imaging unit and an acceleration detector that detects an acceleration of the illumination unit or the imaging unit, and the angular velocity and the acceleration The shape measuring apparatus according to claim 1, wherein the shake is detected based on at least one of the following.

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