CN117053680A

CN117053680A - Image measuring apparatus and touch detector

Info

Publication number: CN117053680A
Application number: CN202310488873.0A
Authority: CN
Inventors: 柏原光宏; 森本雄太; 花冈洋祐
Original assignee: Keyence Corp
Current assignee: Keyence Corp
Priority date: 2022-05-12
Filing date: 2023-05-04
Publication date: 2023-11-14
Also published as: JP2023167383A

Abstract

The present invention relates to an image measuring apparatus and a touch detector. The decline of the measurement accuracy is suppressed by making it difficult to cause lateral sliding of the workpiece upon contact of the touch detector. The touch detector includes: a housing; a detector shaft disposed inside the housing; a stylus detachably attached to the probe shaft and having a contact portion to be brought into contact with a workpiece; a first elastic member connected to the housing and the probe shaft and forming a deflection fulcrum of the probe shaft; a second elastic member that is connected to the housing and the probe shaft at a portion on the axis that is away from the first elastic member, and returns the probe shaft to the origin; and a displacement detection mechanism for detecting displacement of the probe shaft in the three-dimensional direction in a noncontact manner at the base end side of the probe shaft.

Description

Image measuring apparatus and touch detector

Technical Field

The present invention relates to an image measuring apparatus for displaying an image of a workpiece and measuring three-dimensional coordinates of the workpiece using a touch detector, and a touch detector.

Background

Conventionally, as a three-dimensional measurement apparatus for measuring a surface shape and a size of a workpiece, there is known a three-dimensional measurement apparatus configured to bring a touch detector into contact with a surface of a workpiece, specify coordinate values at the time of contact, and calculate the surface shape and the size of the workpiece based on the specified coordinate values.

In general, in a three-dimensional measurement apparatus using a touch detector, in a case where a workpiece slides laterally on a stage due to a force generated when the touch detector is brought into contact, a measurement error occurs, and thus the workpiece is often fixed with a jig (sig) or the like. On the other hand, there are cases where it is desired to place a workpiece on, for example, a glass stage, and in such cases it is sometimes difficult to sufficiently fix the workpiece to the stage. In this case, a low-voltage touch detector capable of detecting contact with the workpiece even at a low contact pressure is required.

As a low-voltage touch detector, for example, a touch detector for detecting a deformation amount of a strain gauge that elastically deforms in accordance with displacement of a stylus is known as disclosed in JP 2002-22433A.

However, in the touch detector using the strain gauge disclosed in JP 2002-22433A, when the strain gauge to which the stylus is connected is elastically deformed, the strain gauge may exert a slight resistance against an external force, thereby generating an elastic stiffness. When the resistance force of the strain gauge is applied, there is a possibility that the lateral sliding of the workpiece is caused upon contact of the touch detector depending on the material of the workpiece or the stage. In particular, a stage of an image measuring apparatus using an image of a workpiece is made of glass having light projection properties, and thus lateral sliding of the workpiece is likely to occur.

It is considered that the lateral sliding of the workpiece can be suppressed by reducing the resistance force of the strain gauge, but there is a possibility that: if the resistance is reduced, the measurement accuracy is lowered due to the influence of various vibrations such as environmental vibrations, vibrations of the stage, and impact vibrations at the time of contact with the workpiece.

Disclosure of Invention

The present invention has been made in view of this point, and an object thereof is to suppress a decrease in measurement accuracy by making it difficult to cause lateral sliding of a workpiece at the time of contact of a touch detector.

According to an embodiment of the present invention, an image measuring apparatus includes: a light projection section for irradiating a workpiece on the stage with detection light; an imaging unit configured to receive the detection light and generate a workpiece image; an image measuring section for measuring a size of the workpiece using the workpiece image generated by the image capturing section; the touch detector is used for outputting a contact signal when the touch detector is in contact with a workpiece on the rack; a driving part for moving at least one of the stage and the touch detector relative to the other to bring the touch detector into contact with a workpiece placed on the stage; and a coordinate measuring section for measuring three-dimensional coordinates of a contact point of the touch detector with the workpiece based on a contact signal output when the touch detector is brought into contact with the workpiece by the driving section, and the image measuring apparatus is configured to be able to measure a size of the workpiece based on a measurement result of at least one of the image measuring section and the coordinate measuring section.

The touch detector includes: a housing; a probe shaft having a rod shape and disposed inside the housing; a stylus detachably attached to a distal end portion of the probe shaft and having a contact portion to be brought into contact with the workpiece; a first elastic member connected to the housing and the probe shaft and forming a deflection fulcrum of the probe shaft; a second elastic member that is connected to the housing and the probe shaft at a portion on an axis remote from the first elastic member, and returns the probe shaft to an origin; and a displacement detection mechanism for detecting displacement of the probe shaft in a three-dimensional direction in a noncontact manner at a base end side of the probe shaft.

According to this structure, when the contact portion of the stylus is brought into contact with the workpiece on the stage, an external force acts on the probe shaft via the contact portion. At this time, in the case of an external force in the radial direction, since the first elastic member forms a deflection fulcrum, the probe shaft swings around the deflection fulcrum. That is, since the first elastic member does not suppress the displacement of the probe shaft, the probe shaft can be displaced in the radial direction at a low pressure, and the displacement in the radial direction can be detected by the displacement detection mechanism. When the external force in the radial direction is removed, the probe shaft returns to the origin by the elastic force of the second elastic member.

Further, as described above, the first elastic member only needs to form a deflection fulcrum when an external force acts in the radial direction, and does not need to suppress displacement of the probe shaft in the axial direction. Therefore, in the case where an external force acts on the probe shaft in the axial direction, the probe shaft can be displaced in the axial direction at a low pressure, and the displacement of the probe shaft in the axial direction can be detected by the displacement detection mechanism. When the external force in the axial direction is removed, the probe shaft returns to the origin by the elastic force of the second elastic member.

Further, the first elastic member may be provided to have a stronger restraining force against displacement in the radial direction of the probe shaft than the second elastic member. In this case, the deflection fulcrum of the probe shaft can be reliably formed by the first elastic member.

Further, the second elastic member may be provided to have a stronger biasing force for biasing the probe shaft toward the origin point than the first elastic member. In this case, the probe shaft can be reliably returned to the origin by the second elastic member.

Further, using a magnetic sensor as the displacement detection mechanism makes it possible to detect the displacement of the detector shaft with high accuracy without obstructing the displacement of the detector shaft when an external force acts on the detector shaft due to the contact of the contact portion with the workpiece.

Further, the displacement detection structure may include: a first displacement detection mechanism for detecting a displacement in a first direction extending along an axial direction of the probe shaft; a second displacement detection mechanism for detecting a displacement in a second direction extending in a radial direction of the probe shaft; and a third displacement detection mechanism for detecting a displacement in a third direction extending in a radial direction of the probe shaft and orthogonal to the second direction. In this case, the displacement in the three-dimensional direction can be detected with high accuracy by the mutually different detection mechanisms.

Further, the first elastic member may be constituted using a leaf spring that extends along an extension line in a radial direction of the probe shaft and has an outer end portion connected to the housing. Therefore, it is possible to suppress displacement of the probe shaft in the axial direction while reliably forming the deflection fulcrum of the probe shaft.

Further, the second elastic member includes three or more extension springs extending radially from the probe shaft and having outer ends connected to the housing, and spring forces of the three or more extension springs are set to be balanced. Thus, when the second elastic member is in contact with the workpiece, displacement in the radial direction is allowed even by a slight external force acting on the probe shaft, thereby realizing a low-voltage touch probe.

Further, damping grease for generating a damping force may be applied to the second elastic member. As a result, the amplitude of the probe shaft in the high frequency range can be dampened. Further, since the grease is used, it is possible to suppress an increase in the displacement resistance of the probe shaft at the time of contact with the workpiece, and to not hinder the return of the probe shaft to the origin.

Furthermore, an attachment and detachment mechanism using a magnet may be provided between the stylus and the probe shaft. As a result, for example, the stylus can be easily replaced with a stylus more suitable for a workpiece on a stage among a plurality of types of styluses prepared in advance, depending on the type of workpiece and measurement use.

Further, the second elastic member may be disposed closer to the distal end side of the probe shaft than the first elastic member, and the displacement detection mechanism may be disposed closer to the proximal end side of the probe shaft than the first elastic member.

As described above, the first elastic member for forming the deflection fulcrum of the probe shaft and the second elastic member for returning the probe shaft to the origin are disposed away from each other in the axial direction, and the displacement of the probe shaft in the three-dimensional direction can be detected in a noncontact manner. Thus, it is possible to provide a low-voltage touch detector that makes it difficult to cause lateral sliding of a workpiece upon contact of the touch detector, thereby making it possible to suppress a decrease in measurement accuracy.

Drawings

Fig. 1 is a diagram showing the overall structure of an image measuring apparatus according to an embodiment of the present invention;

fig. 2 is a perspective view of the apparatus body as seen from above;

fig. 3 is a schematic view of the apparatus body as seen from the front side;

fig. 4 is a schematic view of the apparatus body as seen from the side face side;

fig. 5 is a perspective view of the light receiving lens and its vicinity as seen obliquely from below;

FIG. 6 is a block diagram of an image measurement device;

FIG. 7 is a longitudinal cross-sectional view of a touch detector;

fig. 8 is a plan view of the fulcrum-forming elastic member;

FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 7;

FIG. 10 is a diagram corresponding to FIG. 7 and showing another example of a touch detector;

fig. 11 is a perspective view of the transducer mechanism of the stylus;

fig. 12 is a perspective view of the stylus holding portion;

fig. 13 is a flowchart showing an example of the stylus mounting process;

fig. 14A is a perspective view showing a state in which the housing is arranged above the stylus holding portion at the attachable position;

fig. 14B is a perspective view showing a state in which the housing is lowered and the stylus is mounted;

fig. 15 is a flowchart showing an example of the stylus removal process;

fig. 16 is a flowchart showing an example of a procedure at the time of measurement setting of the image measurement apparatus;

Fig. 17 is a flowchart showing an example of the image generation process;

fig. 18 is a flowchart showing an example of a procedure at the time of measurement setting of image measurement;

fig. 19 is a flowchart showing an example of a procedure at the time of measurement setting of coordinate measurement;

FIG. 20 is a perspective view of a workpiece on a gantry;

FIG. 21 is a plan view of a gantry with a workpiece placed thereon;

FIG. 22 is a longitudinal cross-sectional view of the workpiece on the stage along the Y-direction;

fig. 23 is a diagram showing an example of a user interface screen for setting a contact target position;

fig. 24 is a diagram showing an example of a user interface screen for setting a contact target position with respect to an inclined surface;

fig. 25 is a flowchart showing an example of a process of measurement using a noncontact displacement meter;

FIG. 26 is a diagram showing an example of a user interface screen for displaying geometric elements;

fig. 27 is a diagram showing an example of a user interface screen for overlaying and displaying geometric elements on a three-dimensional image;

fig. 28 is a flowchart showing an example of a detailed procedure of the measurement operation of the touch detector;

fig. 29A is a flowchart showing an example of a procedure of the first half during measurement execution by the image measurement apparatus;

fig. 29B is a flowchart showing an example of a procedure of the latter half during measurement execution by the image measurement apparatus;

Fig. 30 is a flowchart showing an example of a procedure of noncontact measurement at the time of measurement execution;

fig. 31 is a view corresponding to fig. 6 according to a first modification including a three-way image pickup element; and

fig. 32 is a diagram corresponding to fig. 6 according to a second modification including a single-channel image pickup element and a three-channel image pickup element.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following preferred embodiments are merely illustrative in nature and are not intended to limit the invention, its application, or uses.

Fig. 1 is a diagram showing the overall structure of an image measuring apparatus 1 according to an embodiment of the present invention. The image measuring apparatus 1 includes an apparatus body 2, a control unit 3 constituted using a personal computer or the like, and a display section 4, and is configured to be able to perform arithmetic processing on data acquired by the apparatus body 2 in the control unit 3 to measure the size of each portion of the workpiece W, and also to perform quality determination of the measurement result or the like as needed. The control unit 3 may be incorporated in the apparatus body 2 and integrated with the apparatus body 2. Although details will be described later, the data acquired by the apparatus body 2 includes, in addition to image data of the workpiece W, data concerning a contact point when the touch detector 80, which will be described later, is in contact with the workpiece W, data measured by the noncontact displacement meter 70 (shown in fig. 3), and the like.

The display section 4 displays, for example, various setting screens, image data, measurement results, and the like. The display section 4 includes, for example, a liquid crystal display, an organic EL display, or the like. The display section 4 is shown in the present example as a separate member from the apparatus body 2 and the control unit 3, but the display section 4 is not limited thereto and may be incorporated in the apparatus body 2 or the control unit 3.

The image measuring apparatus 1 further includes a keyboard 5, a mouse 6, and the like as operation means of the user. The operation device is not limited to the keyboard 5 and the mouse 6, and may be a touch panel operation device or the like. For example, the control unit 3 may also be constituted using a laptop personal computer, and in this case, the keyboard 5 and the mouse 6 are provided in an integrated manner with the control unit 3 together with the display section 4.

The image measuring apparatus 1 further includes a storage section 7. The storage section 7 may be configured using, for example, a hard disk drive, a solid-state drive, or the like, and is a section for storing various types of data acquired by the apparatus body 2, information set by a user, images, measurement results, quality determination results, and the like. The storage section 7 may be built in the control unit 3, or may be provided outside the control unit 3. In the case where the storage section 7 is provided outside the control unit 3, the storage section 7 may be, for example, cloud storage or the like connected via a communication line such as the internet.

(Structure of device body 2)

As shown in fig. 2, the apparatus body 2 includes a base 20 and a stage 21 horizontally movable with respect to the base 20. Note that the stage 21 can move up and down. Near the central portion of the stage 21, a placing stage 21a made of a light-transmitting member such as glass or the like is provided, and the workpiece W can be placed on the placing stage 21 a. The stage 21 is supported by the base 20 such that the stage 21 is movable in the horizontal direction (the X direction which is the width direction of the apparatus body 2 and the Y direction which is the depth direction of the apparatus body 2). That is, the apparatus body 2 includes an XY-direction driving section 23 (schematically shown in fig. 3 and 4) for driving the stage 21, and the XY-direction driving section 23 can move the stage 21 within a predetermined range in the X-direction and within a predetermined range in the Y-direction. Not only the stage 21 is linearly moved in the X direction and linearly moved in the Y direction, but also the stage 21 may be moved in such a manner that the movement locus is inclined with respect to the X axis and the Y axis in a plan view, or the stage 21 may be moved in such a manner that an arbitrary curve is drawn.

The XY-direction driving section 23 includes an X-direction linear scale 23a configured to detect a moving distance in the X-direction and a Y-direction linear scale 23b configured to detect a moving distance in the Y-direction. The X-direction linear scale 23a enables detection of the position and the moving distance of the stage 21 in the left-right direction. The Y-direction linear scale 23b enables detection of the position and the moving distance of the stage 21 in the depth direction.

The XY direction driving section 23 is controlled by the control unit 3. The XY-direction driving section 23 is controlled based on a control signal output from the control unit 3, the current position of the stage 21 is determined based on detection signals of the X-direction linear scale 23a and the Y-direction linear scale 23b, the stage 21 is moved to a desired position, and the stage 21 is moved in such a manner that a desired movement locus is drawn.

Although in the description of the present embodiment, the Z direction is referred to as the up-down direction or the height direction, the X direction is referred to as the left-right direction, and the Y direction is referred to as the front-rear direction, this is for convenience of description, and does not limit the posture of the apparatus body 2 during use. Further, in many cases, the user is generally on the front side of the apparatus body 2, the side of the apparatus body 2 closer to the user is simply referred to as "front", the side opposite to the user is simply referred to as "rear", the right side viewed from the user is simply referred to as "right side", and the left side viewed from the user is simply referred to as "left side".

As shown in fig. 3 and 4, a transmission illumination 30 as a light projection portion is provided at a lower side portion of the base 20 below the stage 21. As shown in fig. 4, the transmissive illumination 30 includes: a light-emitting device 31 for transmission illumination, for example, having a light-emitting diode or the like; a slit 32 in which light emitted from the light emitter 31 for transmission illumination is transmitted through the slit 32; a mirror 33 configured to direct light transmitted through the slit 32 upward; and a lens 34, wherein the light directed upward by the mirror 33 is incident on the lens 34. The lens 34 is a lens capable of emitting incident light as parallel light. The light emitted from the lens 34 is directed to the placing stage 21a of the stage 21, transmitted through the placing stage 21a, and emitted from below to the workpiece W placed on the placing stage 21 a.

As shown in fig. 2, a measurement start button 2a is provided on the front side of the base 20 of the apparatus body 2. The measurement start button 2a is a button configured to be operated by a user when starting measurement of the workpiece W. In performing measurement, the measurement operation is performed by pressing the measurement start button 2a only once.

The apparatus body 2 includes a support portion 22 and a measurement execution portion 24. As shown in fig. 3 and 4, the support 22 is connected to the rear side portion of the base 20 and extends upward from the rear side portion of the base 20. The measurement performing part 24 is supported by an upper side portion of the supporting part 22. The measurement execution unit 24 is provided with a coaxial epi-illumination 40, an annular illumination 45, an imaging unit 50, a noncontact displacement meter 70, a housing 81 of the touch detector 80, and the like.

The measurement performing portion 24 is formed separately from the supporting portion 22, and is movable in the Z direction with respect to the supporting portion 22. That is, the apparatus body 2 includes a Z-direction driving section 25 for driving the measurement executing section 24, and the measurement executing section 24 is linearly movable from the ascending end position to the descending end position by the Z-direction driving section 25. The imaging axis of the imaging unit 50 coincides with the Z axis, and thus the imaging axis extends in the Z direction. The measurement execution section 24 is an example of a movable unit that moves along the imaging axis of the imaging section 50.

The Z-direction driving section 25 includes a Z-direction linear scale 25a configured to detect a moving distance in the Z-direction, and the Z-direction linear scale 25a can detect the height of the measurement performing section 24, the moving distance in the height direction, and the like. The Z-direction driving section 25 is controlled by a control section 3d included in the control unit 3. The control unit 3d controls the Z-direction driving unit 25 by a control signal, determines the current position of the measurement executing unit 24 based on the detection signal of the Z-direction linear scale 25a, and moves the measurement executing unit 24 to a desired position. The moving speed of the measurement execution section 24 may be changed in a plurality of stages or continuously.

The coaxial epi-illumination 40 is a light projection part, and, as shown in fig. 4, includes, for example, a coaxial epi-illumination light emitter 41 having a light emitting diode or the like, a lens 42 on which light emitted from the coaxial epi-illumination light emitter 41 is incident, and a direction conversion member 43 for directing light emitted from the lens 42 downward. The direction conversion member 43 is configured using a light-transmitting member capable of transmitting light in the up-down direction. The light emitted from the direction conversion member 43 is detection light. The detection light emitted from the direction conversion member 43 is directed to the placing stage 21a of the stage 21, and emitted from above to the workpiece W placed on the placing stage 21a (i.e., the workpiece W on the stage 21).

The image pickup section 50 includes a light receiving lens 51, a beam splitter 52, a high-magnification side imaging lens 53, a low-magnification side imaging lens 54, a high-magnification side image pickup element 55, and a low-magnification side image pickup element 56, and these constitute a first image pickup section. The image pickup section 50 is supported above the stage 21 by the support section 22 in a posture in which the image pickup direction is the normal direction (Z direction) of the stage 21.

Specifically, as also shown in fig. 5, the light receiving lens 51 of the image pickup section 50 is arranged on the lower surface of the measurement execution section 24, and is positioned in such a manner that the light receiving surface faces the upper surface of the placement stage 21a of the stage 21. Accordingly, the detection light emitted from the coaxial epi-illumination 40 and reflected by the surface of the workpiece W may be received by the light receiving lens 51, and the light emitted from the transmission illumination 30 may also be received by the light receiving lens 51.

The optical axis of the light receiving lens 51 coincides with the Z direction. In the present example, the direction conversion member 43 of the coaxial epi-illumination 40 is located directly above the light receiving lens 51, and thus the detection light emitted from the coaxial epi-illumination 40 is transmitted through the light receiving lens 51 and emitted to the workpiece W on the stage 21.

The beam splitter 52 is disposed above the direction conversion member 43, and is configured using a prism that branches light emitted upward from the light receiving lens 51 in two directions. As the beam splitter 52, for example, a cube beam splitter or a flat plate beam splitter may be used. A cube beam splitter is preferable because light passing through the cube beam splitter is not refracted, compared to a flat plate beam splitter, so that the optical axis is not deviated, and alignment adjustment of the branching angle is easy. In this example, light incident on the beam splitter 52 via the light receiving lens 51 is branched to the upper side and the rear side. Thus, a high-magnification side imaging lens 53 is arranged on the upper side of the beam splitter 52, and a low-magnification side imaging lens 54 is arranged on the rear side of the beam splitter 52. Further, a high-magnification-side imaging element 55 is arranged on the upper side of the high-magnification-side imaging lens 53, and light incident on the high-magnification-side imaging lens 53 is imaged on the light receiving surface of the high-magnification-side imaging element 55. Further, a low-magnification-side imaging element 56 is arranged on the rear side of the low-magnification-side imaging lens 54, and light incident on the low-magnification-side imaging lens 54 is imaged on the light receiving surface of the low-magnification-side imaging element 56.

The high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56 are configured using a charge-coupled device (CCD) image sensor, a Complementary MOS (CMOS) image sensor, or the like. The workpiece image acquired by the low-magnification-side image pickup element 56 is a low-magnification image, and the workpiece image acquired by the high-magnification-side image pickup element 55 is a high-magnification image having a higher magnification than the low-magnification image. In this example, the high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56 are each configured using a single-channel image pickup element to acquire a high-resolution workpiece image, thereby improving measurement accuracy. Therefore, the workpiece image output from the high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56 becomes a monochrome image (grayscale image).

The focal position of the imaging unit 50 is adjusted by the Z-direction driving unit 25. That is, the control unit 3d can move the measurement execution unit 24 in the Z direction by controlling the Z direction driving unit 25, but can move the imaging unit 50 along the imaging axis because the Z direction coincides with the direction of the imaging axis of the imaging unit 50. That is, the Z-direction driving section 25 is a focus adjustment mechanism for adjusting the focus position of the image pickup section 50, and the focus of the image pickup section 50 can be adjusted by measuring the movement of the executing section 24 in the direction along the image pickup axis. At the time of focus adjustment, not only autofocus using an algorithm such as a conventionally known contrast scheme or phase difference scheme, but also manual focusing in which a user performs a predetermined operation for adjustment may be performed.

The above-described configuration of the bifurcated optical system including the light receiving lens 51 and the beam splitter 52 enables simultaneous acquisition of a high-magnification image and a low-magnification image without mechanically switching the optical systems. Note that the configuration of the branching optical system using the beam splitter 52 may be omitted, and the high-magnification lens and the low-magnification lens may be mechanically switched to acquire a high-magnification image and a low-magnification image.

The ring illumination 45 is a light projecting portion that irradiates the workpiece W on the stage 21 with monochromatic light (white light) or detection light having a plurality of different wavelengths. Examples of the detection light having a plurality of different wavelengths include red light, green light, and blue light. The annular illumination 45 has a circular shape surrounding the outer periphery of the light receiving lens 51, and is arranged coaxially with the light receiving lens 51 below the light receiving lens 51.

As shown in fig. 6, the ring-shaped illumination 45 includes a red light source 45a for emitting red light, a green light source 45b for emitting green light, and a blue light source 45c for emitting blue light. The red light source 45a, the green light source 45b, and the blue light source 45c are each constituted using a light emitting diode or the like, and can be individually turned on and off. That is, the workpiece W is illuminated with red light by turning on only the red light source 45a, is illuminated with green light by turning on only the green light source 45b, is illuminated with blue light by turning on only the blue light source 45c, and is illuminated with white light by turning on all of the red light source 45a, the green light source 45b, and the blue light source 45c.

The ring-shaped illumination 45 includes an illumination Z-direction driving portion 45d, and the ring-shaped illumination 45 is linearly movable from a rising end position to a falling end position by the illumination Z-direction driving portion 45 d. When the ring illumination 45 moves according to the height of the workpiece W, detection light may be emitted from a place near the workpiece W. The illumination Z-direction driving section 45d includes a Z-direction linear scale 45e configured to detect a moving distance in the Z-direction, and the Z-direction linear scale 45e can detect the height of the ring illumination 45, the moving distance in the height direction, and the like. Note that, in the present embodiment, the annular illumination 45 is arranged outside the housing of the measurement execution portion 24, but the present invention is not limited thereto, and the annular illumination 45 may be arranged inside the housing of the measurement execution portion 24.

As shown in fig. 3, the mirror 33 for guiding the transmission illumination 30 to the stage 21, the annular illumination 45, the direction conversion member 43 for guiding the coaxial epi-illumination 40 to the stage 21, and the image pickup section 50 (for example, the high magnification-side image pickup element 55) are arranged substantially straight in the vertical direction. Then, the annular illumination 45, the direction conversion member 43, and the image pickup section 50 are fixed to the housing of the vertically movable measurement execution section 24 so as to be integrally movable in the Z direction. In addition, in the present embodiment, a housing 81 of a touch detector 80, which will be described later, is also fixed to the housing of the measurement execution section 24 so that the housing 81 is also integrally movable in the Z direction.

The measurement execution unit 24 includes a first stage camera 46, a second stage camera 47, and a front camera 48. Since the measurement performing section 24 is provided at the upper side portion of the support section 22, the first stage camera 46, the second stage camera 47, and the front camera 48 are also provided at the upper side portion of the support section 22. The first stage camera 46, the second stage camera 47, and the front camera 48 each include an image pickup element capable of acquiring a color image. Further, the first stage camera 46, the second stage camera 47, and the front camera 48 have fewer pixels than the high-magnification side image pickup element 55 and the low-magnification side image pickup element 56, but are not limited thereto, and the first stage camera 46, the second stage camera 47, and the front camera 48 may have substantially the same number of pixels.

As shown in fig. 4, the first stage camera 46 and the second stage camera 47 are arranged on the front side of the light receiving lens 51, and are disposed to be spaced apart from each other in the left-right direction. The imaging directions (optical axis directions) of the first stage camera 46 and the second stage camera 47 are the same as the imaging direction of the imaging section 50. The imaging fields of view of the first stage camera 46 and the second stage camera 47 are located on the front side of the imaging field of view of the imaging section 50, and images of the front side portion of the stage 21 can be captured. Note that the first stage camera 46 or the second stage camera 47 captures an image of the entire stage 21 in a bird's eye view manner from directly above to generate a bird's eye view image (planar image), and may be referred to as a bird's eye view image generating section.

The front camera 48 is a second imaging section for capturing an image of the workpiece W above the stage 21 in a posture in which the imaging direction is different from the normal direction of the stage 21 to generate a bird's-eye view image, and may also be referred to as a bird's-eye view image generating section. The front camera 48 is arranged on the front side of the light receiving lens 51, and is positioned on the front side of the first stage camera 46 and the second stage camera 47 in terms of the positional relationship in the front-rear direction. Thus, it can be said that the front camera 48 is a camera disposed closest to the user. The imaging field of view of the front camera 48 is set to be wider than those of the high-magnification side imaging element 55 and the low-magnification side imaging element 56, including those of the high-magnification side imaging element 55 and the low-magnification side imaging element 56, and images outside the imaging fields of the high-magnification side imaging element 55 and the low-magnification side imaging element 56 can also be captured. In this example, the front camera 48 may take an image of the entire upper surface of the stage 21. Further, the front camera 48 is a camera configured to be able to capture an image in real time and to acquire a live view image.

The imaging direction (optical axis direction) of the front camera 48 is directed from obliquely above the front side of the stage 21 to the upper surface of the stage 21, that is, from the front side to the back side when viewed from the user. This is to make the line of sight direction when the stage 21 is viewed from the user at the time of measurement execution substantially coincide with the image pickup direction of the front camera 48. As a result, the bird's eye view image generated by the front camera 48 corresponds to what the user can see when viewing the work W in the bird's eye view manner in the natural measurement posture.

(Structure of noncontact Displacement Meter 70)

The noncontact displacement meter 70 is a noncontact measuring portion for emitting measurement light in the normal direction of the stage 21 and receiving reflected light from the workpiece W on the stage 21 to measure the height of the workpiece W on the stage 21 in a noncontact manner. The noncontact displacement meter 70 is a laser coaxial displacement meter (more specifically, a white confocal displacement meter), and includes a lens unit 71, a light projecting and receiving unit 72, and an optical fiber portion 73 connecting the two units 71 and 72 as shown in fig. 3. The light projection and reception unit 72 is built in the base 20, and includes a laser light source 72a, a light source optical member 72b, a phosphor 72c, and a light receiving element 72d.

The laser light source 72a is configured to emit light having a single wavelength, and preferably blue light or ultraviolet light having a wavelength of 450nm or less. In particular, when blue light is emitted, light in which light that has been used to excite the phosphor 72c and has undergone wavelength conversion and light that has not been used to excite the phosphor 72c but is still blue may be projected onto the workpiece W.

The phosphor 72c is excited by light from the laser light source 72a, and emits light converted to have a different wavelength. The phosphor 72c includes one or more kinds of phosphors 72c, and for example, light converted to yellow light may be excited by blue light and emitted, or two kinds of phosphors 72c excited by blue light and emitting light converted to green and excited by blue light and emitting light converted to red may be used.

The optical fiber portion 73 includes one or more optical fibers. For ease of handling, a ferrule 73a may be used at the end of the fiber. The core diameter of the exit end, which is the end of the optical fiber portion 73 on the lens unit 71 side, may be set to a diameter of 200 μm or less due to an influence on the diameter of the spot formed on the workpiece W, and may be set to a diameter of 50 μm or less.

The phosphor 72c is fixed to the incident end side of the optical fiber section 73. The phosphor 72c may be fixed in a light-transmitting medium such as resin or glass for transmitting the light from the laser light source 72a and the light emitted by the phosphor 72c, and the light-transmitting medium may be fixed at the incident end of the optical fiber section 73. At this time, the refractive index of the light transmitting medium is set to be equal to or lower than the refractive index of the core on the incident end side of the optical fiber section 73, so that the light from the laser light source 72a and the light from the phosphor 72c are efficiently incident on the optical fiber section 73.

The light receiving element 72d is configured using an image pickup element such as a multi-divided Photodiode (PD), a CCD, a CMOS, or the like, and selectively receives light from the workpiece W according to wavelength via a beam splitter 72e configured using a diffraction grating, a prism, or the like, a color selection optical filter, or the like. The light receiving element 72d may receive light from the workpiece W via the optical fiber portion 73, or may receive light via other optical paths.

The lens unit 71 is attached to the measurement execution section 24, and thus is movable in the Z direction together with the image pickup section 50. The lens unit 71 is a member configured to collect light emitted from the emission end of the optical fiber portion 73 toward the workpiece W, and includes an upper lens 71a and a lower lens 71b. The lens unit 71 is disposed on the right side of the image pickup section 50, and has an optical axis extending in the Z direction.

In the case where the lens unit 71 is arranged to have a confocal position with the exit end of the optical fiber portion 73, light from the workpiece W is separated by a beam splitter 72e configured using a diffraction grating, a prism, or the like according to wavelength, and the wavelength-luminance distribution of the light from the workpiece W is detected based on the light receiving position in the light receiving element 72 d. The signal related to the light receiving position and the light receiving amount of the light receiving element 72d is sent to the displacement measuring section 3c provided in the control unit 3.

For example, in the case of using a chromatic aberration lens as the lens unit 71, the displacement measuring section 3c shown in fig. 6 evaluates that the workpiece W exists at a shorter distance when light having a shorter wavelength is detected, and that the workpiece W exists at a longer distance when light having a longer wavelength is detected. Further, in the case of using a diffraction lens as the lens unit 71, the displacement measuring section 3c measures the displacement of the workpiece W by evaluating that the workpiece W exists at a longer distance when light having a shorter wavelength is detected and that the workpiece W exists at a shorter distance when light having a longer wavelength is detected.

As shown in fig. 3, the focal length of the noncontact displacement meter 70 is set longer than that of the image pickup section 50. Further, the focal point height of the noncontact displacement meter 70 is set to be substantially the same as that of the image pickup section 50. That is, the attachment height of the lens unit 71 of the noncontact displacement meter 70 with respect to the measurement performing portion 24 and the attachment height of the image pickup portion 50 with respect to the measurement performing portion 24 may be arbitrarily set, but in this example, the height of the lens unit 71 and the height of the image pickup portion 50 are set so that the focal point height of the noncontact displacement meter 70 and the focal point height of the image pickup portion 50 are substantially the same. For example, the lower lens 71b of the lens unit 71 is arranged above the light receiving lens 51 of the image pickup section 50.

Since the noncontact displacement meter 70 can be moved by the Z-direction driving portion 25 in this example, for example, when the focal length of the image pickup portion 50 and the focal length of the noncontact displacement meter 70 match, height measurement with the noncontact displacement meter 70 can be performed by merely moving the stage 21 in the horizontal direction so that the noncontact displacement meter 70 focuses on the measurement target position at the focal length of the image pickup portion 50.

(Structure of touch Detector)

The touch detector 80 shown in fig. 3 is a member that outputs a contact signal when in contact with the workpiece W on the stage 21. In this example, the touch detector 80 is provided in the measurement execution section 24, and thus the Z-direction driving section 25 can relatively move the touch detector 80 in the Z-direction with respect to the stage 21. Further, the stage 21 can be relatively moved in the XY direction with respect to the touch detector 80 by the XY direction driving section 23. In this way, the Z-direction driving section 25 and the XY-direction driving section 23 move at least one of the stage 21 and the touch detector 80 relative to the other, so that the touch detector 80 can be brought into contact with the workpiece W placed on the stage 21. Note that the stage 21 may be moved in the Z direction, or the touch detector 80 may be moved in the XY direction. An axis orthogonal to the Z axis and coincident with the left-right direction of the apparatus body 2 is defined as an X axis. An axis which coincides with a direction orthogonal to the Z axis and to the X axis (front-rear direction of the apparatus body 2) is defined as a Y axis.

The contact signal output from the touch detector 80 is sent to the coordinate measuring section 3b of the control unit 3 shown in fig. 6. Upon receiving a contact signal output when the touch detector 80 is brought into contact with the workpiece W by the Z-direction driving section 25 and the XY-direction driving section 23, the coordinate measuring section 3b measures the three-dimensional coordinates of the point of contact of the touch detector 80 with the workpiece W based on the contact signal.

For example, the position of the stage 12 in the X direction and the position in the Y direction at the time of outputting the contact signal of the touch detector 80 may be acquired by the X-direction linear scale 23a and the Y-direction linear scale 23b, respectively. Further, the position of the touch detector 80 in the Z direction at the time of outputting the contact signal of the touch detector 80 can be acquired by the Z-direction linear scale 25 a. Further, when the relative positional relationship between the touch detector 80 and the workpiece W is set in advance and the calibration of the image pickup section 50 or the like is performed, the three-dimensional coordinates of the contact point may be measured based on the detection results of the linear scales 23a, 23b, and 25 a.

As shown in fig. 7, the touch detector 80 includes a housing 81, a detector shaft 82, a stylus 83, a fulcrum-forming elastic member (first elastic member) 84, an origin restoring elastic member (second elastic member) 85, and displacement detection mechanisms 86A, 86B, and 86C. The housing 81 has a tubular shape extending in the Z direction, is fixed to the measurement execution section 24 as shown in fig. 5, and is arranged on the left side of the image pickup section 50. Therefore, the image pickup section 50 is interposed between the touch detector 80 and the lens unit 71 of the noncontact displacement meter 70.

As shown in fig. 7, the probe shaft 82 is a rod-shaped member provided inside the housing 81, and extends in the Z direction. An upper cylindrical member 82a having a diameter larger than the outer diameter of the probe shaft 82 is fixed to the lower end of the probe shaft 82. The stylus 83 is also constructed using a rod-like member extending in the Z direction similarly to the probe shaft 82, but is thinner than the probe shaft 82. A contact portion 83b having a spherical shape and contacting the workpiece W is provided at the lower end portion of the stylus 83.

An upper end portion of the stylus 83 is detachably attached to a lower surface of the cylindrical member 82a of the probe shaft 82. That is, a lower cylindrical member 83a having a diameter larger than the outer diameter of the stylus 83 is fixed to the upper end portion of the stylus 83. The upper cylindrical member 82a and the lower cylindrical member 83a have substantially the same diameter, but the dimension in the up-down direction is set longer in the lower cylindrical member 83 a. Note that the probe shaft 82 is integrated with the housing 81, and thus, it can be said that the probe 83 is detachably attached to the housing 81.

Although the attachment and detachment structure of the stylus 83 with respect to the probe shaft 82 is not particularly limited, for example, a motion mount or the like may be used. That is, permanent magnets (not shown) having polarities that are attracted to each other are fixed to the lower surface of the upper side cylindrical member 82a and the upper surface of the lower side cylindrical member 83 a. For example, three steel balls 83c are fixed around the magnet on one of the lower surface of the upper cylindrical member 82a and the upper surface of the lower cylindrical member 83a at equal intervals in the circumferential direction, and an assembling groove (not shown) for assembling the steel balls 83c is formed around the magnet on the other surface in a manner corresponding to the position of the steel balls 83 c. As a result, when the stylus 83 is brought closer to the probe shaft 82 from below the probe shaft 82, the stylus 83 is held in a state of being attracted to the probe shaft 82 by the attraction force of the magnets fixed to the upper cylindrical member 82a and the lower cylindrical member 83 a. Alternatively, when the probe shaft 82 is brought closer to the stylus 83 from above the stylus 83, the stylus 83 is held in a state of being attracted to the probe shaft 82 by the attraction force of the magnets fixed to the upper side cylindrical member 82a and the lower side cylindrical member 83 a. At this time, the stylus 83 is arranged coaxially with the probe shaft 82 when the steel ball 83c is fitted in the fitting groove.

When the stylus 83 is removed from the probe shaft 82, the stylus 83 is moved downward against the magnetic force in a state where the probe shaft 82 is fixed, or the probe shaft 82 is moved upward against the magnetic force in a state where the stylus 83 is fixed. As a result, the lower cylindrical member 83a is separated from the upper cylindrical member 82a, and the stylus 83 is removed.

The fulcrum-forming elastic member 84 is a member connected to the housing 81 and the probe shaft 82 to form a deflection fulcrum of the probe shaft 82, and is constituted using a leaf spring or the like, for example. Specifically, the fulcrum-forming elastic member 84 is constituted using a leaf spring that extends along an extension line in the radial direction of the probe shaft 82, and has a radially outer end portion connected to the inner surface of the housing 81. An example of the shape of the elastic member 84 for fulcrum formation is shown in fig. 8, and the outer shape of the elastic member 84 for fulcrum formation is a circle formed along the inner surface of the housing 81. An insertion hole 84a into which the probe shaft 82 can be inserted is formed in the central portion of the fulcrum-forming elastic member 84, and the probe shaft 82 is fixed in a state of being inserted into the insertion hole 84 a. In the elastic member 84 for forming a fulcrum, the outer side portion 84b, the inner side portion 84c formed with the insertion hole 84a, and six connecting portions 84d connecting the outer side portion 84b and the inner side portion 84c are integrally formed.

The fulcrum-forming elastic member 84 may be made of an elastic material having an axial shape recovery property. Further, the material and shape of the fulcrum-forming elastic member 84 are set so that the inner portion 84c is maintained in the axial center and the radial deviation is suppressed. As a result, the deflection fulcrum of the probe shaft 82 can be held by the fulcrum-forming elastic member 84. Further, when the stylus 83 is in contact with the workpiece W, the fulcrum-forming elastic member 84 deforms with a small force that does not affect the contact resistance. Further, since the probe shaft 82 can be displaced in the Z direction with a small force, the fulcrum-forming elastic member 84 is configured such that the inner side portion 84c can be displaced in the Z direction with a small force with respect to the outer side portion 84 b.

As shown in fig. 7, a support portion 81a configured to support an outer portion 84b (shown in fig. 8) of the fulcrum-forming elastic member 84 from below is provided inside the housing 81. Since the outer side portion 84b is supported by the supporting portion 81a, the probe shaft 82 is held at a predetermined height set in advance and stable, and is less likely to vibrate, so that measurement accuracy is improved.

The origin restoring elastic member 85 is a member that is connected to the housing 81 and the probe shaft 82 at a portion of the probe shaft 82 in the axial direction away from the fulcrum-forming elastic member 84 to restore the probe shaft 82 to the origin. In this way, the fulcrum-forming elastic member 84 configured to form the deflection fulcrum and the origin restoring elastic member 85 configured to restore to the origin are separately provided, and the respective elastic members 84 and 85 are designed to satisfy mutually different functions. That is, in the elastic member for fulcrum-formation 84, the displacement suppression force in the radial direction of the probe shaft 82 is set stronger than in the elastic member for origin restoration 85, and in the elastic member for origin restoration 85, the biasing force for biasing the probe shaft 82 toward the origin is set stronger than in the elastic member for fulcrum-formation 84.

The origin restoring elastic member 85 is provided closer to the distal end side (lower side) of the probe shaft 82 than the fulcrum-forming elastic member 84, includes three or more extension springs 85a, 85b, and 85c (which extend radially from the probe shaft 82 along an extension line in the radial direction of the probe shaft 82 and have outer ends connected to the housing 81) as shown in fig. 9, and is provided so that the spring forces of the three or more extension springs 85a, 85b, and 85c are balanced. Although the three extension springs 85a, 85b, and 85c constitute the origin restoring elastic member 85 in the present example, the number of extension springs 85a, 85b, and 85c is not limited thereto.

The inner end portions of the extension springs 85a, 85b, and 85c are fixed to the outer surface of the probe shaft 82, and such three fixed portions are arranged at equal intervals (120 ° intervals) in the circumferential direction. The axes of the extension springs 85a, 85b, and 85c are orthogonal to the axis of the probe shaft 82, and the extension lines of the axes of the extension springs 85a, 85b, and 85c intersect on the axis of the probe shaft 82. The extension springs 85a, 85b and 85c have the same spring constant.

Here, it is assumed that the detector shaft 82 is displaced in any direction of the three tension springs 85a, 85b, and 85 c. In the case where equilibrium is reached at the position where the tension spring 85a contracts Δa, the remaining tension springs 85b and 85c are in a/2 displacement relationship based on vector division (vector division). The respective strengths of the remaining tension springs 85b and 85c act half way in the direction of the tension spring 85a to finally have a relationship of adding half of the spring strength of the tension spring 85a, and reach equilibrium when a total of 1.5×Δa of strength is applied. Since the three tension springs 85a, 85b, and 85c have the same spring constant, only the spring constant×Δa×1.5 and the spring constant are design parameters. That is, when the same spring constant is set for the extension springs 85a, 85b, and 85c, even if the length for maintaining balance is changed, the touch detector 80 performing pressure contact can be obtained.

Furthermore, the following possibilities exist: since the touch detector 80 making low-voltage contact is used, if a large stroke is applied to the detector shaft 82, the elastic limit may be exceeded or the detector shaft 82 may be deformed. For this reason, it is sometimes desirable to provide a restriction mechanism for protection, and adopt a structure acceptable when receiving a stronger external force. For example, in the case where it is assumed that the contact portion 83b is strongly pushed in the X direction, if the restriction mechanism for this case is located above, the detector shaft 82 receives a bending force, which may cause deformation of the detector shaft 82. That is, if the origin restoring elastic member 85 is located above the fulcrum-forming elastic member 84, the detector shaft 82 that receives a large external force in the X direction as described above may receive a bending force. In this example, the origin restoring elastic member 85 is provided below the fulcrum-forming elastic member 84, so that the probe shaft 82 is less likely to receive bending force. Note that the above-described problem is not applicable to all cases, and thus the origin restoring elastic member 85 may be provided above the fulcrum-forming elastic member 84.

Further, for example, the detector shaft 82 is radially pulled by three tension springs 85a, 85b, and 85c having the same spring constant, and thus, with respect to the origin at which equilibrium is reached at a predetermined elongation, displacement by an amount by which the ratio of H1/H2 decreases by the lever principle with respect to the moving amount of the contact portion 83b (shown in fig. 7) is applied to the tension springs 85a, 85b, and 85c, and the difference from equilibrium can be calculated only by the displacement and the spring constant. For example, assuming that contact with the workpiece W is detected at an extremely low contact pressure of about 2g, the spring constant is reversely derived, so that an extremely simple relationship can be established. Because of this relationship, even if the extension springs 85a, 85b, and 85c are constructed using springs having relatively strong strength, the resistance force at the contact portion 83b does not excessively increase, and the touch detector 80 that performs low-voltage contact can be obtained.

As shown in fig. 7, the displacement detection mechanisms 86A, 86B, and 86C are magnetic sensors that detect displacement of the detector shaft 82 in the three-dimensional direction in a noncontact manner, and are disposed closer to the base end side (upper side) of the detector shaft 82 than the fulcrum-forming elastic member 84. Specifically, the displacement detection mechanisms 86A, 86B, and 86C include: a Z-direction displacement detection mechanism 86A (first displacement detection mechanism) that detects a displacement in a Z direction (first direction) along the axis direction of the probe shaft 82; an X-direction displacement detection mechanism 86B (second displacement detection mechanism) that detects a displacement in an X direction (second direction) along the radial direction of the probe shaft 82; and a Y-direction displacement detection mechanism 86C (third displacement detection mechanism) that detects displacement in a Y direction (third direction) extending along the radial direction of the detector shaft 82 and orthogonal to the Z direction.

The Z-direction displacement detection mechanism 86A includes a Z-direction detection magnet 86A (in which the N-pole and the S-pole are arranged side by side in the Z-direction) and a Z-direction magnetic sensor 86b. The Z-direction detection magnet 86a is fixed to the detector shaft 82, and the Z-direction magnetic sensor 86b is fixed to the housing 81. The Z-direction magnetic sensor 86b is arranged to face the boundary portion between the N pole and the S pole of the Z-direction detection magnet 86 a. Therefore, when the detector shaft 82 is displaced even slightly in the Z direction, the magnetic field detected by the Z-direction magnetic sensor 86b changes, whereby the displacement of the detector shaft 82 in the Z direction can be detected in a noncontact manner.

A magnet fixing member 82b is provided at an upper end portion of the probe shaft 82. The X-direction displacement detection mechanism 86B includes an X-direction detection magnet 86c (in which the N-pole and the S-pole are arranged side by side in the X-direction) and an X-direction magnetic sensor 86d. An X-direction detection magnet 86c is fixed to the upper surface of the magnet fixing member 82b, and an X-direction magnetic sensor 86d is fixed to the housing 81. The X-direction magnetic sensor 86d is arranged to face the boundary portion between the N pole and the S pole of the X-direction detection magnet 86 c. Therefore, when the detector shaft 82 swings slightly in the X direction about the deflection fulcrum and is displaced, the magnetic field detected by the X-direction magnetic sensor 86d changes, whereby the displacement of the detector shaft 82 in the X direction can be detected in a noncontact manner.

The Y-direction displacement detection mechanism 86C includes a Y-direction detection magnet 86e (in which the N-pole and the S-pole are arranged side by side in the Y-direction) and a Y-direction magnetic sensor 86f. The Y-direction detection magnet 86e is fixed to a portion of the upper surface of the magnet fixing member 82b distant from the X-direction detection magnet 86c, and the Y-direction magnetic sensor 86f is fixed to the housing 81. The Y-direction magnetic sensor 86f is arranged to face the boundary portion between the N pole and the S pole of the Y-direction detection magnet 86 e. Therefore, when the detector shaft 82 swings slightly in the Y direction about the deflection fulcrum and is displaced, the magnetic field detected by the Y-direction magnetic sensor 86f changes, whereby the displacement of the detector shaft 82 in the Y direction can be detected in a noncontact manner.

The displacement detection mechanisms 86A, 86B, and 86C may be sensors other than magnetic sensors, and may be, for example, optical or capacitive detection sensors.

Damping grease for generating damping force is applied to the extension springs 85a, 85b and 85c. Damping grease has a high viscosity and a nonvolatile paste, and is applied to the extension springs 85a, 85b, and 85c to fill gaps between wires of the extension springs 85a, 85b, and 85c. As a result, the damping force can be applied multiple times in a short time while the extension springs 85a, 85b, and 85c are extended and contracted, desired damping is easily obtained, and excessive damping that may cause noise also does not need to be applied.

Note that, in damping the extension springs 85a, 85b, and 85c, damping grease or the like can be made effective at a distance where the damping effect is easily enhanced based on the lever principle. For example, the gap between the Z-direction detection magnet 86a and the Z-direction magnetic sensor 86b, the gap between the X-direction detection magnet 86c and the X-direction magnetic sensor 86d, and the gap between the Y-direction detection magnet 86e and the Y-direction magnetic sensor 86f may be filled with damping grease. In addition, other damping members may be used to damp the extension springs 85a, 85b, and 85c.

Fig. 10 is a diagram showing another example of the touch detector 80. In the present example, the orientation of the X-direction magnetic sensor 86d of the X-direction displacement detection mechanism 86B and the orientation of the Y-direction magnetic sensor 86f of the Y-direction displacement detection mechanism 86C are different from both of the above examples. Specifically, the X-direction magnetic sensor 86d and the X-direction detection magnet 86c are arranged to face each other in the horizontal direction, and the Y-direction magnetic sensor 86f and the Y-direction detection magnet 86e are arranged to face each other in the horizontal direction.

(transducer mechanism of stylus)

Examples of the stylus 83 include cross-shaped styli having different overall shapes, L-shaped styli, T-shaped styli, and the like, styli having different diameters, and styli having different sizes of contact portions 83b at the front end, and the like, and are selectively used according to the workpiece W, measurement application, and the like. As shown in fig. 1 and 2, the support portion 22 of the apparatus body 2 is provided with a transducer mechanism (changer) 100, which transducer mechanism (changer) 100 holds different contact pins 83A, 83B, and 83C, and automatically replaces a desired contact pin at a predetermined timing. In the present example, the touch detector 80 is disposed on the left side of the measurement execution section 24, and thus the transducer mechanism 100 is disposed on the left side of the support section 22 in a corresponding manner to the touch detector 80. Note that, in the case where the touch detector 80 is provided on the right side of the measurement execution section 24, the transducer mechanism 100 may be provided on the right side of the support section 22.

Fig. 11 is a perspective view of the transducer mechanism 100 of the stylus. The transducer mechanism 100 includes a stylus holding portion 101 for holding one or more styluses, an arm portion 102 for supporting the stylus holding portion 101, a transducer rotation driving portion (rotating portion) 103 for rotating the arm portion 102, and a transducer feed driving portion (slider portion) 104 for moving the stylus holding portion 101 along the arm portion 102.

As shown in fig. 12, the stylus holding portion 101 includes first to third cutout portions 101a, 101B, and 101C that hold different types of styluses 83A, 83B, and 83C, respectively. Each of the cutout portions 101a, 101b, and 101c is open in the up-down direction and also open to one side in the horizontal direction, and the opening direction is the same in all of the cutout portions 101a, 101b, and 101c. Note that fig. 12 shows the third cutout portion 101c from which the member for forming the upper side portion has been removed for the purpose of explaining the internal structure, but the third cutout portion 101c also has the same shape as the first cutout portion 101a and the second cutout portion 101 b. Note that the number of notched portions is not limited to three, and may be set to any number.

Holding claws 101d configured to hold the stylus are provided at intermediate portions in the up-down direction of the cutout portions 101a, 101b, and 101c, respectively. The holding claw 101d is made of a member having elasticity such as resin, and has a shape that opens in the same direction as the open portions of the cutout portions 101a, 101b, and 101c each in the horizontal direction. The both end portions of the holding claw 101d protrude from the inner surfaces of the respective cutout portions 101a, 101b, and 101c, and the both end portions of the holding claw 101d are engaged with the groove 83d formed in the outer peripheral surface of the lower cylindrical member 83a of the stylus 83. The dimension of the groove 83d in the up-down direction is set longer than the dimension of the holding claw 101d in the up-down direction, and the difference between the dimensions enables the stylus held by the holding claw 101d to relatively move up-down with respect to the holding claw 101d.

The interval between both end portions of the holding claw 101d is narrower than the outer diameter of the portion of the lower cylindrical member 83a where the groove 83d is formed. When the lower cylindrical member 83a is held, the portions of the lower cylindrical member 83a where the grooves 83d are formed are pressed against both end portions of the holding claw 101d from the open side of the holding claw 101d, so that the holding claw 101d is elastically deformed to widen the interval between both end portions. As a result, the portion of the lower cylindrical member 83a where the groove 83d is formed can be inserted from the gap between the both end portions of the holding claw 101d to the inside of the holding claw 101d and engaged with the holding claw 101 d. When the lower cylindrical member 83a held by the holding claw 101d is to be removed, the lower cylindrical member 83a is relatively moved in the opening direction of the holding claw 101d, so that the holding claw 101d is elastically deformed to widen the interval between the both end portions, and the lower cylindrical member 83a is disengaged from the opening side of the holding claw 101 d.

The arm portion 102 shown in fig. 11 is a member configured to move between an attachable position where the contact pins 83A, 83B, and 83C (reference numerals 83B and 83C are shown in fig. 2) held by the contact pin holding portion 101 can be attached to the housing 81, and a retracted position retracted from the attachable position. The attachable position may also be referred to as a stylus attachment ready position, and the retracted position may also be referred to as a stylus storage position. Specifically, the arm portion 102 is constructed using a member extending in the horizontal direction, and has a base end portion attached to the support portion 22 via the inverter rotation driving portion 103. The inverter rotation driving unit 103 is configured using an electric motor having a rotation shaft 103a extending in the Z direction. The rotation shaft 103a is parallel to the imaging axis of the imaging section 50, and the base end side of the arm 102 is connected to the lower end portion of the rotation shaft 103 a.

As shown by the broken line in fig. 2, the inverter rotation driving section 103 is arranged above the stage 21. Fig. 2 shows a state in which the styluses 83A, 83B, and 83C held by the stylus holding portion 101 are moved to the retracted positions. The stylus holding portion 101 and the styli 83A, 83B, and 83C at the retracted positions are arranged so that no interference occurs during measurement setting and during measurement execution, specifically so that the stylus holding portion 101 and the styli 83A, 83B, and 83C do not enter the movable range of the measurement execution portion 24 or the imaging field of view of the imaging portion 50.

The support portion 22 includes an eave portion 22A covering at least a part of the upper portion of the stylus holding portion 101 at the retracted position. The eave portion 22A is formed to protrude leftward from the left wall portion of the support portion 22, and the stylus holding portion 101 may be disposed directly under the eave portion 22A. As a result, surrounding articles and the like can be prevented from coming into contact with the stylus holding portion 101 and the styluses 83A, 83B, and 83C held by the stylus holding portion 101. The eave portion 22A may be formed to cover the entire upper portion of the stylus holding portion 101.

As shown in fig. 11, the arm 102 is provided with an inverter feed driving section 104. The inverter feed driving section 104 includes a feed electric motor 104a, a screw rod 104b rotationally driven by the feed electric motor 104a, and a screw member 104c screw-connected to the screw rod 104 b. The feed electric motor 104a is fixed to the base end portion of the arm portion 102, and the rotation center line thereof is oriented in the longitudinal direction of the arm portion 102. The screw rod 104b is arranged in parallel with the arm 102, and is rotatably supported with respect to the arm 102. The stylus holding portion 101 is fixed to the screw member 104c.

The arm 102 is provided with a guide rail 102a for guiding the stylus holding portion 101 in the longitudinal direction of the arm 102. The stylus holding portion 101 is movable only in the longitudinal direction of the arm portion 102 in a state of being engaged with the guide rail 102a so as not to be rotatable. That is, the styli 83A, 83B, and 83C held by the stylus holding portion 101 can be moved in the direction orthogonal to the imaging axis.

When the screw rod 104b is rotated by the feeding electric motor 104a, as shown in fig. 11, the stylus holding portion 101 may be moved to the tip end side of the arm portion 102, and although not shown, the stylus holding portion 101 may be moved to the base end side of the arm portion 102 or the vicinity thereof. The stylus holding portion 101 can be stopped at an arbitrary position with respect to the arm portion 102. The position of the stylus holding portion 101 is detected by a position detector such as a rotary encoder and is output to the control portion 3d.

Fig. 11 shows the following state: the contact pins 83A, 83B, and 83C held by the contact pin holding portion 101 are moved to attachable positions where they can be attached to the housing 81. The position of the inverter rotation driving part 103 is set such that the rotation shaft 103A of the inverter rotation driving part 103 is located between the contact pins 83A, 83B, and 83C at attachable positions and the contact pins 83A, 83B, and 83C at retracted positions, and the inverter rotation driving part 103 at such positions is attached to the supporting part 22.

The inverter rotation driving part 103 rotates the arm 102 by 180 ° when moving the stylus holding part 101 from the retracted position to the attachable position and from the attachable position to the retracted position. That is, the position of the stylus holding portion 101 can be largely switched from the front side to the rear side of the inverter rotation driving portion 103 and from the rear side to the front side thereof.

Next, an overview of stylus replacement will be described. Fig. 13 is a flowchart showing an example of the stylus mounting process. In step SA1 after the start, the control section 3d of the control unit 3 controls the Z-direction driving section 25 to move the measurement executing section 24 to the upper standby position. In step SA2, the control section 3d controls the inverter feed driving section 104 to move the stylus holding section 101 in the longitudinal direction of the arm section 102 such that a desired one of the first to third cutout sections 101a, 101b, and 101c (provided as the first cutout section 101 a) is arranged at a predetermined position. As a result, the stylus holding portion 101 moves outward from the space immediately below the eave portion 22A (for example, the stylus holding portion 101 is moved to the vicinity of the center of the arm portion 102 and is withdrawn to the outside of the eave portion 22A). In step SA3, the control section 3d controls the inverter rotation driving section 103 to rotate the arm section 102 so that the stylus holding section 101 is arranged at the attachable position. This state is shown in fig. 14A. Since the measurement performing part 24 is at the upper standby position, the stylus 83A has not yet been attached to the housing 81. Note that, after step SA3, the position of the stylus holding portion 101 may be finely adjusted along the longitudinal direction of the arm portion 102.

After that, the flow advances to step SA4, and the control section 3d controls the Z-direction driving section 25 to move the measurement executing section 24 down to the mounting height. Then, the lower cylindrical member 83A of the stylus 83A is attracted to the upper cylindrical member 82a of the probe shaft 82 by magnetic force. Fig. 14B shows a state after adsorption. Next, the flow advances to step SA5, and in step SA5, the control section 3d controls the inverter rotation driving section 103 to rotate the arm section 102 so that the stylus holding section 101 is arranged at the retracted position. At this time, the holding claw 101d is elastically deformed so that the lower side cylindrical member 83a comes out of the holding claw 101 d.

Next, a process for detaching the stylus attached to the housing 81 is shown in fig. 15. In step SB1 after the start, similarly to step SA4, the control section 3d of the control unit 3 controls the Z-direction driving section 25 to move the measurement executing section 24 to the installation height. In step SB2, the control section 3d controls the inverter feed driving section 104 to move the stylus holding section 101 in the longitudinal direction of the arm section 102 such that a desired one of the first to third cutout sections 101a, 101b, and 101c (provided as the first cutout section 101 a) is arranged at a predetermined position. At this time, the cutout portion that does not hold the stylus is arranged at a predetermined position. Further, the stylus holding portion 101 moves outward from the space immediately below the eave portion 22A (for example, the stylus holding portion 101 moves near the center of the arm portion 102 and withdraws to the outside of the eave portion 22A).

In step SB3, the control portion 3d controls the inverter rotation driving portion 103 to rotate the arm portion 102 so that the stylus holding portion 101 is arranged at the attachable position. This flow is a flow during disassembly and thus does not correspond to the "attachable" state, but the stylus holding portion 101 is at the same position as the "attachable position" in the flow shown in fig. 13, and thus the "attachable position" is also used in this flow. The "attachable location" may be replaced with the "detachable location". This state is the same as that shown in fig. 14B, and the holding claw 101d is engaged with the portion of the lower cylindrical member 83A of the stylus 83A where the groove 83d is formed.

After that, the flow advances to step SB4, and the control section 3d controls the Z-direction driving section 25 to move the measurement executing section 24 up to the upper standby position. Then, the upper cylindrical member 82a of the probe shaft 82 is relatively moved upward with respect to the lower cylindrical member 83A of the stylus 83A, and the lower cylindrical member 83A of the stylus 83A is disengaged from the upper cylindrical member 82a of the probe shaft 82 against the magnetic force. The state after the detachment is the same as that shown in fig. 14A. Next, the flow proceeds to step SB5, in which the control portion 3d controls the inverter rotation driving portion 103 to rotate the arm portion 102 so that the stylus holding portion 101 is arranged at the retracted position.

As described above, the control section 3d controls the changer rotation driving section 103 and the changer feed driving section 104 so that the stylus held by the stylus holding section 101 is arranged from the retracted position to the attachable position, and controls the changer rotation driving section 103 and the changer feed driving section 104 so that the stylus held by the stylus holding section 101 is arranged from the attachable position to the retracted position. Further, the control section 3d controls the inverter feed driving section 104 such that the stylus holding section 101 at the retracted position is positioned closer to the base end side of the arm section 102 than the stylus holding section 101 at the attachable position.

Note that, in the present embodiment, the holding claw 101d is configured to engage with the groove 83d formed on the outer peripheral surface of the lower cylindrical member 83a, but a modification in which the groove 83d is not formed is also conceivable. For example, a movable member (preferably an elastic member) that is relatively movable (abutted or separated) in the radial direction with respect to the outer peripheral surface of the lower cylindrical member 83a may be provided inside each of the cutout portions 101a to 101 c. The movable member is movable by the control section 3 d. In this case, in step SA4 described above, after the lower cylindrical member 83A of the stylus 83A is attracted to the upper cylindrical member 82a of the probe shaft 82, the control section 3d controls the movable member to be separated from the outer peripheral surface of the lower cylindrical member 83A. In step SB4, the control unit 3d controls the movable member to abut on the outer peripheral surface of the lower cylindrical member 83a before the measurement execution unit 24 is moved up to the upper standby position. In this way, the attaching and detaching operation of the stylus 83a can be achieved without forming the groove 83d on the outer peripheral surface of the lower cylindrical member 83 a.

(Structure of control Unit)

The control unit 3 shown in fig. 6 includes, for example, a Central Processing Unit (CPU), RAM, ROM, an internal bus, and the like (not shown). The CPU is connected to the display section 4, the keyboard 5, the mouse 6, the storage section 7, and the apparatus body 2 via an internal bus. The control unit 3 acquires the operation states of the keyboard 5, the mouse 6, the measurement start button 2a of the apparatus body 2, and the like. Further, the control unit 3 may acquire image data acquired by the image pickup section 50, the first stage camera 46, the second stage camera 47, and the front camera 48 of the apparatus body 2. Further, the result of the calculation in the control unit 3, and the image data and the like acquired by the image pickup section 50, the first stage camera 46, the second stage camera 47, and the front camera 48 may be displayed on the display section 4.

The control unit 3 controls the Z-direction driving unit 25, the XY-direction driving unit 23, the coaxial epi-illumination 40, the annular illumination 45, the illumination Z-direction driving unit 45d, the imaging unit 50, the noncontact displacement meter 70, the touch detector 80, the inverter rotation driving unit 103, the inverter feed driving unit 104, and the like of the apparatus body 2. Specifically, the control unit 3 is connected to each hardware via an internal bus, thus controlling the operation of the above hardware, and executes various software functions according to the computer program stored in the storage section 7. For example, the control unit 3 is provided with: an image measuring unit 3a for measuring the size of the workpiece W based on the workpiece image generated by the imaging unit 50; a coordinate measuring unit 3b that measures three-dimensional coordinates of a contact point at which the touch detector 80 contacts the workpiece W; and a displacement measuring section 3c that measures the displacement of the workpiece W on the stage 21 based on an output signal from the noncontact displacement meter 70; etc. Displacement measurements are also referred to as height measurements.

Hereinafter, details of functions that can be executed by the control unit 3 will be described respectively at the time of measurement setting before measurement for the workpiece W and at the time of measurement execution of measurement for the workpiece W.

(at the time of measurement setting)

Fig. 16 is a flowchart showing an example of a procedure at the time of measurement setting of the image measurement apparatus 1. In step SC1 after the start, a plan view image is generated. That is, an image of the gantry 21 is captured by the image capturing section 50. At this time, in a case where the user places the workpiece W on the placing table 21a of the stage 21, a workpiece image is acquired. For example, after the measurement execution section 24 is moved by the Z-direction drive section 25 to move the image pickup section 50 to the measurement position, the image pickup section 50 may be used to take an image of the workpiece W on the stage 21, and may also be used to perform illumination as needed.

In step SC2, a bird's eye view image is generated. After the measurement execution section 24 is moved by the Z-direction drive section 25 to move the front camera 48 to the measurement position, an image of the workpiece W on the stage 21 is taken by the front camera 48.

When the front camera 48 is used to capture an image of the workpiece W, the following control can be performed. That is, first, the control section 3d detects the position of the workpiece W on the stage 21 based on the workpiece image generated by the image pickup section 50. Thereafter, the control section 3d determines whether the workpiece W on the stage 21 is located within the field of view of the front camera 48 based on the detected position of the workpiece W on the stage 21 and the known field of view of the front camera 48. Next, in a case where the workpiece W on the stage 21 is located outside the field of view of the front camera 48, the control section 3d controls the XY direction drive section 23 to move the stage 21 so that the workpiece W on the stage 21 is located within the field of view of the front camera 48. As a result, the front camera 48 can reliably capture an image of the workpiece W on the stage 21.

Further, after capturing an image of the workpiece W on the stage 21 by the front camera 48, the control section 3d may also control the XY direction drive section 23 to move the stage 21 so that the front camera 48 can capture an image of another area on the stage 21.

The positional information of the stage 21 at the time of capturing the bird's eye view image by the front camera 48 may be acquired by the X-direction linear scale 23a or the Y-direction linear scale 23 b. The acquired positional information of the gantry 21 and the bird's eye view image may be stored in association with each other in the storage portion 7. As a result, the position of the gantry 21 at the time of capturing the bird's eye view image can be grasped.

In step SC3, it is determined whether to generate a color workpiece image (color image) based on the result selected by the user. If the user desires to generate a color image, color image generation is selected on the user interface screen displayed on the display section 4, and if the user does not desire to generate a color image, color image generation is not selected. The user's selection operation is performed by the keyboard 5, the mouse 6, or the like, and is received by the receiving section 3e of the control unit 3.

If the user does not desire to generate a color image (that is, if it is determined in step SC3 that a color image is not generated), the flow proceeds to step SC4, and a grayscale workpiece image (grayscale image) is generated based on the data acquired by the image pickup section 50 with illumination of monochromatic light. On the other hand, if the user desires to generate a color image (that is, if it is determined in step SC3 that a color image is generated), the flow proceeds to step SC5, and a color image is generated.

The image generation in each of steps SC4 and SC5 will be described in detail based on the flowchart shown in fig. 17. In step SD1 after the start of fig. 17, the workpiece W is illuminated by the transmission illumination 30. In step SD2, the XY-direction driving section 23 is controlled to move the stage 21 in the X-direction or the Y-direction, and the workpiece W is searched for while the image pickup section 50 is made to take an image of the workpiece W. For example, the stage 21 is moved in a spiral shape from the center in the X direction and the center in the Y direction. Then, in the case where the ratio of black pixels (pixels having a luminance value equal to or smaller than a predetermined value) in the image captured by the image capturing section 50 becomes equal to or larger than a certain value, it is determined that the workpiece W is present in the region. In this way, the workpiece W can be searched, the position of the workpiece W on the stage 21 can be specified, and the size of the workpiece W, the portion occupied by the workpiece W on the stage 21, and the like can be specified.

In step SD3, the image pickup unit 50 picks up an image of the workpiece W searched for in step SD 2. At this time, when a grayscale image is to be generated, the image pickup section 50 picks up an image in a state where all of the red light source 45a, the green light source 45b, and the blue light source 45c of the ring illumination 45 are lighted to illuminate the workpiece W with white light.

On the other hand, when a color image is to be generated, the above-described gradation workpiece image is acquired, and further, the color information generating section 3f of the control unit 3 generates color information of the workpiece W based on a plurality of workpiece images generated by the image capturing section 50 every time each detection light beam having a plurality of different wavelengths is emitted from the ring illumination 45. Specifically, a workpiece image during red illumination captured by the image capturing section 50 in a state where only the red light source 45a is turned on, a workpiece image during green illumination captured by the image capturing section 50 in a state where only the green light source 45b is turned on, and a workpiece image during blue illumination captured by the image capturing section 50 in a state where only the blue light source 45c is turned on are generated. The color information generating section 3f acquires hue and saturation as color information from the three workpiece images.

The control section 3d generates a color image obtained by adding the color information of the workpiece generated by the color information generating section 3f to the gradation workpiece image. Here, an RGB image including three channels of red, green, and blue may be converted into an HSV image including hue (H), saturation (S), and brightness value (V). The color information corresponds to hue (H) and saturation (S). To add color information to a single channel image, a new color image may be generated by assigning desired color information to hue (H) and saturation (S) with the single channel image as a brightness value (V). In this example, a color image is generated by combining the hue and saturation acquired by the color information generating section 3f with the brightness value of the gradation workpiece image. Note that the color space is not limited to HSV, and processing using other color spaces such as HLS may also be performed.

When a color image is to be generated, the grayscale workpiece image is an image directly used for measurement, and thus is obtained using a high-magnification image captured by the high-magnification side image pickup element 55, and a workpiece image for generating color information (i.e., a workpiece image during red illumination, a workpiece image during green illumination, and a workpiece image during blue illumination) is obtained using a low-magnification image captured by the low-magnification side image pickup element 56. Accordingly, a color image is acquired by adding color information generated based on a low-magnification image to a grayscale workpiece image that is a high-magnification image. Since the depth becomes deeper in the image capturing by the low-magnification-side image capturing element 56, color information having a wide range and a deep depth can be acquired in a short time by acquiring a workpiece image for generating color information by the low-magnification-side image capturing element 56. The acquired color information may be added to the workpiece image of shallow depth captured by the high magnification side imaging element 55.

As the gradation workpiece image, an image photographed under different photographing conditions (exposure, illumination intensity, illumination type, lens magnification, and the like) from the workpiece image used to generate color information can be used. In addition, color information may be added to the workpiece image obtained under different illumination conditions, focusing conditions, and the like. Further, even if the image captured in real time by the image capturing section 50 has a single channel, the color information acquired by the color information generating section 3f may be added.

Next, the flow advances to step SD4. In step SD4, it is determined whether or not an image of a portion adjacent to the range of the image captured in step SD3 needs to be captured. The search result in step SD2 is used in this determination. When there is also a workpiece W outside the range of the captured image in step SD3 and the image of the portion needs to be captured, yes is determined in step SD4, and the flow advances to step SD5. In step SD5, the XY-direction driving section 23 is controlled to move the stage 21 so that another portion of the workpiece W enters the imaging field of view of the imaging section 50. After that, the flow advances to step SD3, and an image of a portion different from the portion photographed for the first time is photographed by the image pickup section 50. Steps SD5 and SD3 are repeated as many times as necessary, and a connection process of connecting the plurality of workpiece images thus acquired is performed. That is, the control section 3d controls the XY direction driving section 23 and the imaging section 50, generates a plurality of workpiece images for different portions of the workpiece, and generates a connection image (which is an image of a region wider than the imaging field of view of the imaging section 50) by connecting the generated plurality of workpiece images. The color information of the workpiece generated by the color information generating section 3f is also added to the connection image. As a result, a color connection image can be acquired. Note that if it is determined as no in step SD4, no additional image capturing is required, and thus the flow ends.

Thereafter, the flow advances to step SC6 in the flow chart shown in fig. 16. In step SC6, the control section 3d causes the display section 4 to display the color image in the case where the color image is generated in step SC5, and causes the display section 4 to display the gradation image in the case where the gradation image is generated in step SC 4. In addition, in the case of generating the connection image, the control section 3d causes the display section 4 to display a color connection image or a gradation connection image. In addition, in the case of generating a live view image, the control section 3d causes the display section 4 to display a color live view image or a gray scale live view image.

In step SC6, a bird's eye view image captured by the front camera 48 may be displayed on the display unit 4. When the front camera 48 captures a plurality of bird's-eye view images, the plurality of bird's-eye view images may be displayed as thumbnail images on the display unit 4. That is, the bird's eye view images are reduced in size and displayed side by side in a predetermined direction. When the user selects any one of the reduced images, the control unit 3d causes the display unit 4 to display a bird's eye view image corresponding to the selected reduced image.

In step SC7, the measuring instrument is judged. The measuring instrument includes an image measuring section 3a for measuring the size of the workpiece W based on the workpiece image, a coordinate measuring section 3b for measuring three-dimensional coordinates using the touch detector 80, and a displacement measuring section 3c for measuring displacement using the noncontact displacement meter 70. The user can select any measuring instrument among the image measuring section 3a, the coordinate measuring section 3b, and the displacement measuring section 3c. For example, in the case where an operation of selecting a measuring instrument is performed on the user interface screen displayed on the display section 4, such a selection operation is received by the receiving section 3 e.

The flow proceeds to step SC8 when it is determined in step SC7 that the image measuring unit 3a is selected, to step SC9 when it is determined that the coordinate measuring unit 3b is selected, and to step SC10 when it is determined that the displacement measuring unit 3c is selected.

Details of the case where image measurement is selected (step SC 8) are shown in the flowchart shown in fig. 18. In step SE1 after the start, the control section 3d changes the imaging condition to one corresponding to the image measurement of the workpiece W. The imaging conditions include illumination, exposure time, and the like.

In step SE2, the receiving unit 3e receives the shape type specified by the user. In step SE3, the receiving unit 3e receives the specification of the edge extraction area by the user. The edge extraction area may be set as an area that is extracted as an edge on the workpiece image and used for measurement. In step SE4, the image pickup section 50 picks up an image of the workpiece W on the stage 21. In step SE5, a plurality of edge points are detected on the workpiece image acquired in step SE 4. Edge points may be detected based on changes in luminance values on the workpiece image. In step SE6, a fit line through a plurality of edge points is calculated. Then, in step SE7, the image measuring unit 3a calculates the size using the fitted line. The image measuring unit 3a measures the size of the workpiece W based on the high-magnification image generated by the high-magnification-side imaging element 55.

Details of the case where the coordinate measurement is selected (step SC 9) are shown in the flowchart shown in fig. 19. Steps SF1 to SF6 after the start are the same as SE1 to SE6 in the flowchart shown in fig. 18. Thereafter, in step SF7, the scan lines used for coordinate measurement (i.e., the scan lines of the touch detector 80) are calculated. In step SF8, a measurement operation using the touch detector 80 is performed. After that, the fitting line is calculated again in step SF9, and then the coordinate measuring section 3b calculates the size in step SF 10.

Here, details of the coordinate measurement will be described with specific examples. Fig. 20 is a perspective view showing a state in which the workpiece W is placed on the stage 21, and fig. 21 is a plane image obtained by photographing an image of the workpiece W in a state placed on the stage 21 from above. In fig. 20 and 21, absolute coordinates in a three-dimensional space surrounded by the stage 21, the support portion 22 (shown in fig. 2 and the like), and the image pickup portion 50 are represented by X, Y and Z.

The workpiece W includes a side surface S1 extending along the Z direction, an upper surface S2 extending along the XY direction, an inclined surface S3 inclined at a predetermined inclination angle with respect to the Z direction, and a hole H1 opened on the upper surface S2 and extending along the Z direction. Further, an alignment mark M for positioning is provided on the upper surface S2.

At the time of measurement setting, a plan view image of the workpiece as shown in fig. 21 is displayed on the display section 4. On the workpiece image displayed on the display section 4, the user sets a first contact target position P1 serving as a reference for bringing the touch detector 80 into contact with the side surface S1 of the workpiece W in the XY direction, a second contact target position P2 serving as a reference for bringing the touch detector 80 into contact with the upper surface S2 of the workpiece W in the Z direction, and a feature pattern for specifying the position and posture of the workpiece W at the time of measurement execution in association with each other. The above setting may be performed by the setting section 3g of the control unit 3. Note that the "first contact target position P1" and "second contact target position P2" mentioned here are concepts including not only a point of contact for bringing the touch detector 80 into contact with the workpiece W but also an operation start position and an end position, etc., which will be described later.

In this example, the feature pattern is an alignment mark M. When the feature pattern is to be set, the user operates the mouse 6 or the like to designate an area such that the feature pattern is included on the workpiece image as shown by the rectangular frame line 200 of fig. 21. The method for setting the feature pattern is not limited to the illustrated example, and a free curve may be used to specify an area, and a method of specifying only the feature pattern may be used. Further, the feature pattern may be set by a method in which the setting section 3g performs automatic extraction.

The feature pattern may be a shape, a pattern, a color, a symbol, a character, or the like of a part of the workpiece W, and may also be referred to as feature amount information. Further, the feature pattern only needs to be information for specifying the position and posture of the workpiece W at the time of measurement execution on the workpiece image displayed on the display section 4, and may be any type of information. The feature quantity information may include a plurality of feature patterns.

In fig. 21, a third contact target position P3 and a fourth contact target position P4 are also provided. The third contact target position P3 is a position serving as a reference for bringing the touch detector 80 into contact with the inner surface of the hole H1 of the workpiece W in the XY direction, and the fourth contact target position P4 is a position serving as a reference for bringing the touch detector 80 into contact with the inclined surface S3 of the workpiece W in the normal direction of the inclined surface S3. The setting section 3g may set the third contact target position P3, the fourth contact target position P4, and the feature pattern in association with each other.

The plurality of first contact target positions P1 may be set based on absolute coordinates, may be set to be spaced apart from each other in the Y direction as shown in fig. 21, and may be set to be spaced apart from each other in the Z direction as shown in fig. 22. As shown in fig. 22 and 23, the display portion 4 may display a longitudinal section of the workpiece W. Each of the arrangements may be provided in a longitudinal section of the workpiece W.

As surrounded by the frame line 201 of fig. 21, the setting portion 3g extracts and sets the side surface S1 of the workpiece W as a first edge measurement element (straight edge element) on the workpiece image. The first edge measurement element corresponds to the outer surface of the workpiece W, and thus can be extracted accurately and clearly by illumination using the transmission illumination 30. The setting section 3g sets the first edge measurement element in association with the extracted first contact target position P1. In addition to the automatic setting described above, the user can manually set the edge by operating the mouse 6 or the like.

For example, a user interface screen 210 for setting a contact target position as shown in fig. 23 may be generated by the control section 3d and displayed on the display section 4. The user interface screen 210 for setting is provided with a section display area 211 that displays a section of the workpiece W, and a parameter setting area 212. In the parameter setting area 212, a plurality of parameters for setting the first contact target position P1 may be set. For example, the number of measurement points in the XY direction may be set as the horizontal direction parameter. In the present example, as shown in fig. 21, the number of measurement points in the XY direction is two, and thus the number of measurement points in the XY direction is set to two, but the number of measurement points is not limited thereto. As many measurement points as the number of measurement points set are displayed on the display section 4. The number of measurement points is the number of contact target positions of the touch detector 80 to be arranged.

The setting section 3g may set the position in the XY direction on the workpiece image when the first contact target position P1 is set. For example, the position of the first contact target position P1 in the XY direction is set by moving the first contact target position P1 on the workpiece image using the mouse 6 or the like. Further, for example, the position of the first contact target position P1 in the XY direction may be arbitrarily set by inputting the separation distance from the reference position in each of the X direction and the Y direction using the keyboard 5 or the like, respectively. Further, the height position of the first contact target position P1 in the Z direction may be set in the same manner.

The horizontal direction parameter may include a setting parameter in the measurement direction. The measurement direction is the approaching direction of the touch detector 80 toward the contact target position. The measurement directions shown in fig. 23 are shown by arrows and are set from right to left, but there are cases where it is desirable to set the opposite directions according to the workpiece W. In this case, the user clicks "reverse direction" to select the reverse direction. This operation is set by the setting section 3g and then stored in the storage section 7 as the approaching direction.

Further, the approaching direction includes a first approaching direction in which the touch detector 80 is moved from above to approach the workpiece W and a second approaching direction in which the touch detector 80 is made to approach the inclined surface S3 of the workpiece W in the normal direction, and the approaching direction may be arbitrarily selected by the user.

As the vertical direction parameter, the number of measurement points in the Z direction, the starting margin, and the measurement range may be set. In the present example, the number of measurement points in the Z direction is two. The start margin is the dimension in the Z direction from the upper surface S2 of the workpiece W to the upper first contact target position P1. The measurement range is a dimension from the upper first contact target position P1 to the lower first contact target position P1.

In the parameter setting area 212, parameters related to the scan line may also be set. The scan line may also be defined as a path for moving the touch detector 80 from a position not in contact with the workpiece W to a position in contact with the workpiece W. The parameter related to the scan line is path information of the touch detector 80 when the touch detector 80 is brought close to the workpiece W, and a close path of the touch detector 80 to the contact target position may be the scan line. The scan line may be straight or curved.

The start position (start point) of the scanning line is an operation start position of the touch detector 80, and any distance that the start position will have in the horizontal direction from the edge position of the side surface S1 of the workpiece W may be set to a specific size. Further, any distance that the end position of the scanning line will have from the edge position of the side surface S1 of the workpiece W toward the inside of the cross section of the workpiece W may be set to a specific size. Even if the scanning line reaches the inside of the cross section of the workpiece W, the scanning is automatically stopped when the touch detector 80 contacts the workpiece W.

The plurality of second contact target positions P2 may also be set based on absolute coordinates, and may be set to be spaced apart from each other in the X direction and the Y direction as shown in fig. 21. The parameter of the second contact target position P2 is different from the parameter of the first contact target position P1, and the number of measurement points in the X direction and the number of measurement points in the Y direction are set. The setting of the vertical direction parameters is omitted. The setting section 3g extracts and sets a line as a boundary between the upper surface S2 and the inclined surface S3 of the workpiece W as a second edge measurement element (straight edge element) on the workpiece image, but the second edge measurement element (portion surrounded by the frame line 202) and the second contact target position P2 are not associated with each other.

The plurality of third contact target positions P3 may also be set based on absolute coordinates, may be set to be spaced apart from each other in the circumferential direction of the hole H1, and may be set to be spaced apart from each other in the Z direction. In the case of the hole H1, a position close to the central axis from the inner surface of the hole H1 in plan view is set as a start position. The approaching direction is a direction from a position approaching the central axis from the inner surface of the hole H1 toward the inner surface of the hole H1, and the direction can also be set by the user interface as shown in fig. 23. In addition, in the case of the hole H1, the measurement points are arranged side by side in the circumferential direction, and the number of measurement points may also be set. The parameters of the third contact target position P3 may be set similarly to those of the first contact target position P1.

The setting section 3g extracts and sets the peripheral edge portion of the hole H1 as a third edge measurement element (rounded edge element) on the workpiece image. The setting section 3g sets the third contact target position P3 in association with the extracted third edge measurement element (the portion surrounded by the frame line 203). In the case where the workpiece W has a cylindrical portion, measurement points of the cylindrical portion may be set in the same manner.

The plurality of fourth contact target positions P4 may also be set based on absolute coordinates. Fig. 24 shows a user interface screen 210 for setting a contact target position with respect to an inclined surface. The horizontal direction parameter of the parameter setting area 212 is similar to that at the time of setting the first contact target position P1, but there is a difference in setting of the inclination direction parameter. As the tilt direction parameter, the number of measurement points in the tilt direction, the start margin, and the measurement range may be set. The start margin is the dimension in the direction along the inclined surface S3 from the second edge measurement element to the fourth contact target position P4 on the upper side shown in fig. 21. The measurement range is a size from the fourth contact target position P4 on the upper side to the fourth contact target position P4 on the lower side. Further, the inclination angle α of the inclined surface S3 may also be set. The inclination angle α of the inclined surface S3 is angle information in the vicinity of the contact target position of the touch detector 80, and the setting section 3g can also receive an input of the inclination angle α. The setting unit 3g sets the fourth contact target position P4 in association with the second edge measurement element (the portion surrounded by the frame line 202 in fig. 21). Various types of setting information set as described above are stored in the storage section 7.

In the measurement setting, a measurement range in which the size measurement is performed may also be set. For example, in the case where it is desired to measure only the upper surface S2 of the workpiece W, the user sets a measurement range on the workpiece image displayed on the display section 4 so as to surround only the upper surface S2. The receiving section 3e is configured to be able to receive a setting of a measurement range by a user. The setting information of the measurement range received by the receiving section 3e is also stored in the storage section 7.

Next, details of step SC10 (measurement using the noncontact displacement meter 70) in the flowchart shown in fig. 16 are shown in the flowchart shown in fig. 25. In step SG1 after the start, parameters for noncontact displacement measurement are set. After that, the flow advances to step SG2, and the control section 3d receives designation of the height measurement location on the workpiece image. In step SG2, the position in the XY direction is specified. For example, the user may confirm a desired measurement site while viewing the workpiece image displayed on the display section 4 and designate the measurement site using the mouse 6 or the like, or may input position designation information such as coordinates or the like as a numerical value to designate the measurement site. Multiple measurement sites may be designated.

After the specification of the measurement site, the flow proceeds to step SG3, and the control section 3d controls the stage 21 so that the measurement site specified in step SG2 is irradiated with the measurement light of the noncontact displacement meter 70. Specifically, the control unit 3d controls the Z-direction driving unit 25 and the XY-direction driving unit 23 so that the focal point of the noncontact displacement meter 70 coincides with the measurement site designated in step SG 2. Then, in step SG4, measurement light is emitted to perform measurement. In step SG5, the displacement measuring section 3c calculates the size. At this time, an averaging process to be described later may be performed.

After step SC10 in the flowchart of fig. 16, the flow advances to step SC11. In step SC11, a measurement tool is set. For example, a tool for measuring the separation size between the wires, a tool for measuring the diameter, a tool for measuring the angle, and the like may be displayed in a list form on the display section 4 so that the user can select a desired tool. Saving the measurement tool selected by the user.

In step SC12, the measurement result by the measurement tool set in step SC11 is superimposed and displayed on the workpiece image on the display section 4. In the case where a color image is acquired, the measurement result is superimposed and displayed on the color image. The setting of the range in which the measurement results are displayed in a superimposed manner may also be received in advance by the receiving section 3 e. At the time of measurement setting, for example, if the user designates a range in which it is desired to superimpose and display the measurement result on the color image displayed on the display section 4, the range is received by the receiving section 3e and then stored in the storage section 7. At the time of measurement execution, the specified range is read from the storage section 7, and the measurement result is displayed in a superimposed manner only within the specified range. Note that in the case where a live view image is acquired, the measurement result may be displayed in a moving image.

In step SC13, for example, when the measurement result by the image measuring unit 3a is acquired, the measurement result by the image measuring unit 3a is superimposed and displayed on the bird's eye view image generated by the front camera 48. In step SC13, for example, as shown in fig. 26, geometric elements 221 and 222 corresponding to the measurement result of the image measurement section 3a may also be displayed on the bird's eye view image. Fig. 26 is another example of the user interface screen 220 for displaying geometric elements 221 and 222 (shown by bold lines) on the display section 4, and the workpiece image and the geometric elements 221 and 222 corresponding to the shape of the measurement element of the workpiece image are displayed in a superimposed manner. The geometric elements 221 and 222 may have a rectangular shape or the like in addition to the straight line and the circular shape, and need only have a shape corresponding to the measurement element. The geometric elements 221 and 222 are set as edge measurement elements by the setting section 3g, and include straight edges, circular edges, rectangular edges, and the like.

The arrangement positions and the number of the contact target positions of the touch detector 80 may be made to correspond to the respective measurement elements. For example, the geometric element 221 and the geometric element 222 may be respectively associated with different positions as positions where the contact target positions are arranged, and may be respectively associated with different numbers of contact target positions. A correspondence relationship between the shape type or size of the measurement element and the arrangement position and number of the touch detectors 80 with respect to the contact target position of the measurement element may be stored in the storage section 7. Note that the shape type, size, and the like of the geometric element may also be set on the bird's eye view image.

The bird's eye view image is an image generated by the front camera 48, and the workpiece image from which the geometric elements 221 and 222 are extracted is an image generated by the image pickup section 50 different from the front camera 48, and thus there is a possibility that: when the geometric elements are superimposed and displayed on the bird's eye view image without correction, the deviation occurs. However, the present example is configured so that correction processing of correcting the deviation of the geometric element with respect to the bird's eye view image before measurement can be performed. Examples of deviations of the geometric elements include deviations due to optical characteristics of the camera and the lens, deviations of the camera, and the like. The correction process may be performed when the image measuring apparatus 1 is shipped from the factory, or may be performed after shipment. The correction process may be performed by any method, and an example thereof will be described below.

In the correction process, for example, a correction workpiece (not shown) having a dot chart (dot chart) or the like is prepared, and placed on the stage 21. An image of the correction workpiece on the stage 21 is captured by the imaging unit 50, and the center coordinates of the respective dots are detected. The front camera 48 also captures an image of the correction work on the stage 21, and detects the center coordinates of the respective dots. The correction table is generated as an internal parameter so that the center coordinates detected based on the image of the image pickup section 50 and the center coordinates detected based on the image of the front camera 48 can be transformed. Instead of the correction table, a transform function may be used. Then, the correction table is applied to the image captured by the image capturing section 50 to perform conversion to projection coordinates.

The correction processing includes, for example, an external parameter detection processing. That is, the image of the correction work on the stage 21 is captured by the image capturing section 50, and the three-dimensional coordinates of the center of each dot are detected. The internal parameters are used to obtain the center coordinates of the individual dots in the projection coordinates of the image of the front camera 48. A transformation matrix of the respective images is obtained. Further, the positions and postures of the imaging section 50 and the front camera 48 are defined in three-dimensional space. A transformation matrix between the center coordinates detected based on the image of the image pickup section 50 and the center coordinates detected based on the image of the front camera 48 for the detected dots is obtained.

In step SC13 of the flowchart shown in fig. 16, as shown in fig. 27, the measurement result and the geometric elements 231 and 232 may be superimposed and displayed on the user interface screen 230 capable of three-dimensionally displaying the workpiece W.

In step SC14, it is determined whether or not other measurement elements are not present. If there are any other measurement elements, the flow returns to step SC7. If no other measurement elements are present, the flow proceeds to step SC15. In step SC15, a pattern search is set. For example, as shown in fig. 21, an alignment mark M as a feature pattern may be set as a search object. In this case, the user may generate the frame line 200 surrounding the alignment mark M, and may designate an area in the frame line 200 as a search area.

In step SC16, setting information set in each process shown in the present flowchart is stored in the storage section 7. That is, the feature pattern (feature amount information) set by the setting section 3g, the relative positional relationship between the first contact target position P1 and the second contact target position P2 with respect to the feature pattern, and the like are stored. Further, for example, a fixed positional relationship or the like between the image pickup section 50 and the touch detector 80 is also stored in the storage section 7. The fixed positional relationship is a relative positional relationship of the touch detector 80 with respect to the image pickup section 50, and may be, for example, a relationship indicated by coordinate information, or a relationship indicated by a relative separation distance, a separation direction, or the like.

(measurement operation of touch Detector)

Next, details of the measurement operation of the touch detector 80, that is, details of step SF8 in the flowchart shown in fig. 19 will be described based on the flowchart shown in fig. 28. After the start, although not shown in this flow, the control section 3d controls the Z-direction driving section 25 to move the measurement executing section 24 upward to the retracted position, and then mounts the desired stylus 83 to the touch detector 80 using the transducer mechanism 100. After that, the flow advances to step SH1, and the contact portion 83b of the touch detector 80 is relatively moved to the start point of the scanning line set on the setting user interface screen 210 shown in fig. 23. Specifically, the control section 3d controls the XY-direction driving section 23 to move the stage 21 in the XY direction and to make the XY coordinates of the start point of the scanning line coincide with those of the contact section 83b of the touch detector 80. After that, the control section 3d controls the Z-direction driving section 25 to lower the measurement executing section 24, and places the contact section 83b of the touch detector 80 at the start point of the scanning line.

In step SH2, the control section 3d controls the XY-direction driving section 23 and the Z-direction driving section 25 so that the contact section 83b of the touch detector 80 relatively moves in the direction of the scanning line (the arrow direction in fig. 23 and 24). In step SH3, it is determined whether or not the touch detector 80 detects a contact. If the touch detector 80 does not detect any contact, the contact portion 83b of the touch detector 80 is kept relatively moving in the direction of the scan line. When the contact portion 83b of the touch detector 80 is in contact with the workpiece W, the movement is stopped, and the determination in step SH3 is yes, and the flow advances to step SH4.

In step SH4, the coordinate measuring section 3b acquires X, Y and Z coordinates when the contact section 83b of the touch detector 80 is in contact with the workpiece W, and uses the X, Y and Z coordinates as measurement values. In step SH5, the control section 3d controls the XY-direction driving section 23 and the Z-direction driving section 25 to return the contact section 83b of the touch detector 80 to the start point of the scanning line. In step SH6, it is determined whether or not the measurement is completed for all the scanning lines. In the case where the measurement is completed for all the scanning lines, the flow proceeds to step SH7, and the control section 3d controls the Z-direction driving section 25 to move the measurement performing section 24 upward to the retracted position. Thereafter, the stylus 83 is detached from the transducer mechanism 100 and stored in the retracted position as required.

In the case where the judgment in step SH6 is no and there is a scanning line for which measurement has not been completed, the flow advances to step SH8 to judge the retraction method. In the case where the retraction method is a method of retracting in the Z direction, the flow proceeds to step SH9, and the control section 3d controls the Z-direction driving section 25 to move the measurement performing section 24 upward to the retracted position. In step SH10, the control unit 3d controls the XY-direction driving unit 23 to relatively move the contact portion 83b of the touch detector 80 to the start point (X, Y) of the scanning line. Thereafter, in step SH11, the control unit 3d controls the Z-direction driving unit 25 to relatively move the contact portion 83b of the touch detector 80 to the start point (Z) of the scanning line.

In the case where the retraction method is a polygon retraction method, the flow advances to step SH12. In step SH12, the control section 3d controls the XY-direction driving section 23 to relatively move the center of the contact section 83b of the touch detector 80 to the start point (X, Y) of the scanning line so that a polygon is formed along the circumferential direction of the measurement element.

Without retracting, the flow advances to step SH13, and the control section 3d controls the XY direction drive section 23 to relatively move the contact section 83b of the touch detector 80 to the start point (X, Y) of the scanning line.

(at the time of measurement execution)

Fig. 29A and 29B are flowcharts showing an example of a procedure at the time of measurement execution by the image measurement apparatus 1. In step SI1 after the start, the setting information stored in the storage section 7 is read. For example, a feature pattern, a search area, a relative positional relationship between the first contact target position P1 and the second contact target position P2 with respect to the feature pattern, a fixed positional relationship between the image pickup section 50 and the touch detector 80, and the like are read. Since this step is provided, the user does not need to move the touch detector 80 to set the reference coordinates every time the workpiece W is placed on the stage 21, thereby simplifying the measurement work.

In step SI1, the position of the measurement element on the workpiece image and the shape type or size of the measurement element are read from the storage unit 7. Further, the correspondence relationship between the shape type or size of the measurement element and the arrangement position and number of the touch detector 80 with respect to the contact target position of the measurement element is also read from the storage section 7.

In step SI2, the imaging unit 50 captures a plan view image by photographing the gantry 21 from above, and displays the plan view image on the display unit 4. In step SI2, the connection image may be displayed, or a bird's eye view image captured by the front camera 48 may be displayed. Further, the image pickup section 50 may acquire a connection image using either one of the high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56, or may acquire a connection image using both image pickup elements, respectively. As described above, since the configuration of the branching optical system using the beam splitter 52 is adopted in the present embodiment, a high-magnification image and a low-magnification image can be acquired simultaneously, and a first connection image obtained by connecting the high-magnification images and a second connection image obtained by connecting the low-magnification images can be acquired.

In step SI3, it is determined whether or not ghost display is performed. For example, if the user selects "execute ghost display" at the time of measurement setting, it is determined yes in step SI3, the flow proceeds to step SI4, and the control section 3d executes ghost display of the search area on the display section 4 to guide placement of the workpiece W at an appropriate position on the stage 21. The ghost display is to superimpose and display a search area set in advance at the time of measurement setting on the plan view image, and for example, display the search area shallower than the plan view image so as not to interfere with recognition of the plan view image. If the user selects "do not perform ghost display" at the time of measurement setting, it is determined as "no" in step SI3, and the flow advances to step SI5. Ghost display may be performed on a connection image, a bird's eye view image, or the like.

In step SI5, it is determined whether or not a search area is specified. That is, in the case where the user designates the search area of the feature pattern at the time of measurement execution, it is judged yes in step SI5, and the flow proceeds to step SI6. On the other hand, in the case where the user does not specify the search area, the flow advances to step SI7. When the user performs an operation of surrounding a specific area by operating the mouse 6 or the like on any of, for example, a plan view image, a connection image, a bird's eye view image, or the like, a search area is specified. At this time, for example, in the case where a bird's eye view image obtained by photographing the entire workpiece W using the image pickup section 50 (which may be the stage cameras 46 and 47 or the front camera 48) is displayed on the display section 4, the user's designation of the search area on the bird's eye view image displayed on the display section 4 may be received. Note that the search range can be specified more easily by using the image pickup section 50 or the stage cameras 46 and 47 that pick up an image from directly above than the front camera 48 that picks up an image obliquely.

In step SI7, it is determined whether the measurement start button 2a is pressed. Steps SI2 to SI7 are repeated until the measurement start button 2a is pressed, and the flow proceeds to step SI8 at the timing when the measurement start button 2a is pressed. In step SI8, it is determined whether or not the bird's eye view image is displayed on the display unit 4. If the user selects "display bird's-eye view image" at the time of measurement setting, it is determined as yes in step SI8, the flow proceeds to step SI9, and the control section 3d causes the display section 4 to display the bird's-eye view image captured by the front camera 48. If the user selects "not to display the bird's eye view image" at the time of measurement setting, no is determined in step SI8, and the flow advances to step SI10.

In step SI10, it is determined whether or not a color image is generated. If the user selects "generate color image" at the time of measurement setting, yes is determined in step SI10, and the flow proceeds to step SI12. In step SI12, a color image of the workpiece W (a workpiece image newly generated for measurement) is generated by a process similar to the process in step SC5 shown in fig. 16. On the other hand, if the user selects "no color image is generated" at the time of measurement setting, no is determined in step SI10, and the flow advances to step SI11. In step SI11, a gradation image of the workpiece W (a workpiece image newly generated for measurement) is generated by a process similar to the process in step SC4 shown in fig. 16.

Next, the flow advances to step SI13 of fig. 29B. In step SI13, a pattern search target image is acquired. For example, the control unit 3d may acquire, as the pattern search target image, a color image of the workpiece W newly generated for measurement in step SI11 or a grayscale image of the workpiece W newly generated for measurement in step SI 12. After the pattern search target image is acquired, the flow proceeds to step SI14, and the control section 3d specifies the position and posture of the feature pattern from the workpiece image newly generated for measurement. At this time, in the case where the user designates the search area in step SI6, the position and posture of the feature pattern are designated by narrowing down to the designated search area. As a result, the processing speed is improved.

Further, in the case where the connection image is set as the workpiece image, the control section 3d controls the XY-direction driving section 23 to move the stage 21 in the XY direction until the workpiece W enters the field of view of the imaging section 50. When the workpiece W enters the field of view, the image pickup unit 50 picks up an image of the workpiece W that has entered the field of view. After that, the stage 21 is moved in the XY directions so that the other part of the workpiece W enters the field of view, and then the image pickup section 50 picks up an image of the other part of the workpiece W that has entered the field of view. A connection image obtained by connecting a plurality of images acquired in this manner is used as a workpiece image, and the position and posture of the feature pattern are specified from the connection image. In this case as well, in the case where the search area is specified by the user, the position and posture of the feature pattern are specified by narrowing down to the specified search area.

After that, the flow advances to step SI15. In step SI15, the control section 3d specifies the first contact target position P1 and the second contact target position P2 for measurement based on the relative positional relationship between the first contact target position P1 and the second contact target position P2 with respect to the workpiece W specified in step SI14 and the characteristic pattern, and the fixed positional relationship between the image pickup section 50 and the touch detector 80. For example, in the case where at least one of the position and the posture of the workpiece W based on the workpiece image newly generated at the time of measurement execution is different from the position or the posture of the workpiece W used at the time of measurement setting, the position or the posture of the workpiece W may be corrected based on the position and the posture of the workpiece W specified in step SI 14. The position is specified by an X-coordinate and a Y-coordinate, and the posture is specified by a rotation angle around the X-axis and a rotation angle around the Y-axis. The correction position may be referred to as position correction, and the correction posture may be referred to as posture correction, but these may be collectively referred to as position correction.

When the relative positional relationship between the first contact target position P1 and the second contact target position P2 with respect to the feature pattern is used at the time of the positional correction, the first contact target position P1 and the second contact target position P2 can be designated as positions similar to those at the time of the measurement setting even after the correction.

Further, the control section 3d may perform pattern search on the workpiece image newly generated for measurement by the image pickup section 50 to specify an edge measurement element, extract an edge from the specified edge measurement element, and specify the first contact target position P1 and the second contact target position P2 based on the extracted edge. The third contact target position P3 and the fourth contact target position P4 shown in fig. 21 can also be specified in the same manner. Since the fourth contact target position P4 is a position specified on the inclined surface S3, the fourth contact target position P4 can be specified using the inclination angle α of the inclined surface S3 when the fourth contact target position P4 is specified. Since the inclination angle α is known, the normal direction of the inclined surface S3 can be estimated. As a result, the fourth contact target position P4 can be designated as a position at which the touch detector 80 is brought into contact with the inclined surface S3 of the workpiece W in the normal direction of the inclined surface S3.

After the contact target position is specified, the flow proceeds to step SI16. In step SI16, in the case where there are a plurality of measurement sites, the order of the measurement sites is determined.

Steps SI17 to SI20 are the same as steps SC7 to SC10 in the flowchart shown in fig. 16. For example, in the case of performing image measurement in step SI18, measurement is performed only within the measurement range received by the receiving unit 3 e. As a result, the measurement accuracy is improved.

Further, for example, in step SI19, the control section 3d controls the XY direction drive section 23 so that the touch detector 80 is in contact with the side surface of the workpiece W with the first contact target position P1 for measurement designated in step SI15 as a reference. Further, the control section 3d controls the Z-direction driving section 25 so that the touch detector 80 is in contact with the upper surface of the workpiece W with the second contact target position P2 for measurement designated in step SI15 as a reference. At this time, the touch detector 80 is relatively moved along the scanning line set at the time of measurement setting, and reflects the number of measurement points, the start margin, the start position, the end position, the approaching direction, and the like.

When the touch detector 80 is to be moved relatively to the workpiece W, the control section 3d controls the Z-direction driving section 25 and the XY-direction driving section 23 so that the touch detector moves in the approaching direction set in fig. 23. At this time, the relative movement speed is set to the first speed until the touch detector 80 is in contact with the workpiece W, and when the contact is detected, the touch detector 80 is returned from the contact position by a predetermined distance. Thereafter, the touch detector 80 is relatively moved at a second speed lower than the first speed until it is in contact with the workpiece W, and a measurement result is output based on the contact position at the second speed. This enables precise measurement.

Further, when the touch detector 80 is to be brought into contact with the inclined surface of the workpiece W, the touch detector 80 is brought close to the inclined surface of the workpiece W at a first speed, and at a point in time when the distance between the touch detector 80 and the inclined surface of the workpiece W becomes a predetermined distance, the relative movement speed is set to a second speed. Then, the measurement result is output based on the contact position at the second speed.

Further, in step S1, the control section 3d reads the position of the measurement element on the workpiece image, the shape type or size of the measurement element, and the correspondence relationship between the shape type or size of the measurement element and the arrangement position and number of the touch detectors 80 with respect to the contact target position of the measurement element. Accordingly, the control section 3d may specify a plurality of contact target positions of the touch detector 80 based on the positions of the measurement elements on the workpiece image, the shape type or size of the measurement elements, and the correspondence relationship, and control the XY-direction driving section 23 and the Z-direction driving section 25 so that the touch detector 80 sequentially moves to the specified plurality of contact target positions. Since a plurality of contact target positions of the touch detector 80 are automatically specified based on information at the time of measurement setting, and the XY-direction driving section 23 and the Z-direction driving section 25 are automatically controlled in this way, the measurement work of the user is simplified.

In step SI20, a noncontact height measurement using the noncontact displacement meter 70 is performed. At this time, there are cases where: the height measurement is performed a plurality of times with the noncontact displacement meter 70, and an averaging process of averaging the plurality of acquired height measurement values is performed. A specific example will be described with reference to a flowchart shown in fig. 30.

In step SJ1 after the start, the control section 3d drives the Z-direction drive section 25 to move the measurement execution section 24 so that the focal point of the noncontact displacement meter 70 matches the measurement site. In step SJ2, it is determined whether or not the measured value can be read by the noncontact displacement meter 70. In the case where the measured value is not readable, the flow proceeds to step SJ3 to perform rough search, that is, the measurement execution section 24 is moved to a position where the measured value is readable by the noncontact displacement meter 70. In the case where the measured value can be read in step SJ2, the flow advances to step SJ3 to perform fine search. In the fine search, the measurement execution section 24 is moved to perform focus adjustment so that the measured value of the noncontact displacement meter 70 becomes approximately zero.

In step SJ5, it is determined whether or not the measured value of the noncontact displacement meter 70 is smaller than the convergence determination value. The convergence determination value may be set to about 0.2mm, for example, but is not limited thereto. In the case where the judgment in step SJ5 is no and the measurement value of the noncontact displacement meter 70 is equal to or greater than the convergence judgment value, the flow advances to step SJ6 to judge whether the feedback iteration number is exceeded. The feedback iteration number may be set to 5 times, for example, but is not limited thereto. The flow proceeds to step SJ4 if the number of feedback iterations is not exceeded, and the flow proceeds to step SJ7 if the number of feedback iterations is exceeded. In step SJ7, it is determined whether the automatic adjustment is OFF (OFF). In the case of automatic adjustment ON (ON), the flow advances to step SJ8, and it is determined whether or not the second peak of the light receiving waveform of the noncontact displacement meter 70 is acquired. In the case where the second peak is acquired, the flow proceeds to step SJ11 to set the transparency mode since the workpiece W is estimated as a transparency. In the case where the second peak has not been acquired, the flow advances to step SJ12 to set the non-transparent mode since the workpiece W is estimated to be a non-transparent body.

After that, the flow advances to step SJ13. In step SJ13, the diameter of a rose curve (rose curve) used in the averaging process of the measured values during scanning is set to a small diameter. In step SJ14, the control unit 3d controls the stage 21 so that the focal point of the noncontact displacement meter 70 becomes a locus (locus) on which a rose curve is drawn on the surface of the workpiece W. The pattern formed by the rose curves in the averaging process is a point-symmetrical and line-symmetrical pattern. The center of the rose curve is set as the measurement target point. The diameter of the rose curve may be selectable by the user from predetermined values such as 0.25mm, 0.5mm, 1mm, etc.

Whether to perform the averaging process may be selectable by a user. For example, the following configuration may also be adopted: a user selection of execution or non-execution of the averaging process is received on the user interface such that the averaging process is executed when execution is selected and the averaging process is not executed when non-execution is selected.

In step SJ14, it is further determined whether the measured value variance during the scan of the rose curve is less than the auto-tuning threshold. The auto-adjustment threshold may be set to about 0.005mm, for example, but is not limited thereto. In the case where the measured value variance during scanning of the rose curve is equal to or greater than the auto-adjustment threshold, the rose curve is set to on (averaging processing is performed). On the other hand, in the case where the measured value variance during scanning of the rose curve is smaller than the auto-adjustment threshold, a highly accurate measured value can be obtained without performing the averaging process, and thus the rose curve is set to be off (no averaging process is performed).

Next, the flow advances to step SJ17 to perform measurement, and then advances to step SJ18 to calculate the size. While the measurement is performed, a scan of the rose curve is performed to maintain the measurements at a plurality of points. During the size calculation, an averaging process of the measured values at a plurality of points is performed to determine an output value.

After the measurement is performed as described above, the flow advances to step SI21 of fig. 29B. In step SI21, it is determined whether or not measurement is completed for all measurement sites. The flow proceeds to step SI17 in the case where there are still measurement sites, and to steps SI22 and SI23 in the case where measurement is completed for all measurement sites. In steps SI22 and SI23, the measurement result is superimposed and displayed on the workpiece image as in steps SC12 and SC13 of the flowchart shown in fig. 16.

In the measurement with the noncontact displacement meter 70, the control section 3d may perform extraction processing of extracting an edge measurement element to be used in the image measurement on the workpiece image. In the case where the edge measurement element is successfully extracted in this extraction process, the control section 3d performs image measurement and height measurement with the noncontact displacement meter 70.

Further, in the measurement with the noncontact displacement meter 70, the control section 3d may move the stage 21 in a direction orthogonal to the imaging axis of the imaging section 50 so that the focal point of the noncontact displacement meter 70 coincides with the measurement site, then perform the height measurement with the noncontact displacement meter 70 to determine whether or not the height measurement value is acquired, and in the case where the height measurement value is not acquired, control the Z-direction drive section 25 so that the noncontact displacement meter 70 moves along the imaging axis until the height measurement value is acquired. Therefore, the noncontact displacement meter 70 is moved in the imaging axis direction together with the imaging section 50 by using the Z-direction driving section 25 for adjusting the focal position of the imaging section 50, and therefore, in the case of performing highly accurate height measurement using the noncontact displacement meter 70, the measurement time can be shortened.

(indicator)

As shown in fig. 6, the apparatus body 2 is provided with an indicator 2c. The indicator 2c is provided on the user-facing surface of the apparatus body 2 and is controlled by the control unit 3. The indicator 2c indicates the measurement result described above, and includes, for example, a light emitting portion, a display portion, and the like. The control unit 3 controls the indicator 2c so that a difference is displayed between a case where the measurement result satisfies the predetermined condition and a case where the measurement result does not satisfy the predetermined condition. The predetermined condition is set in advance by the user and stored in the storage section 7 or the like. For example, if the measurement result is equal to or greater than a certain value, red or the like is displayed as defective, and if the measurement result is less than a certain value, green or the like is displayed as non-defective.

(modification)

Fig. 31 shows a first modification in which the high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56 of the image pickup section 50 are three-channel image pickup elements. That is, since the high-magnification-side image pickup element 55 and the low-magnification-side image pickup element 56 are configured using a three-channel image pickup element including RGB, the annular illumination 45 can generate a color workpiece image by projecting only one color of white light.

In the first modification, the control unit 3 includes a converter 3h. The converter 3h is a part that converts the color workpiece image generated by the image pickup section 50 into a grayscale workpiece image, and the conversion can be performed by conventionally known techniques. The image measuring section 3a is configured to measure the size of the workpiece W based on the grayscale workpiece image converted by the converter 3h.

The color information generating unit 3f generates color information of the workpiece W based on the color workpiece image generated by the imaging unit 50. The control section 3d generates a color image obtained by adding the color information of the workpiece W generated by the color information generating section 3f to the gradation workpiece image converted by the converter 3 h. As a result, the display section 4 can display a color image obtained by adding the color information of the workpiece generated by the color information generating section 3f to the gradation workpiece image converted by the converter 3h, and display the result of the size measurement obtained by the image measuring section 3a in a superimposed manner on the color image.

Next, a second modification shown in fig. 32 will be described. The second modification includes: a first image pickup section 50A that includes a single-channel image pickup element and receives detection light to generate a grayscale workpiece image; and a second image pickup section 50B that includes three-channel image pickup elements including RGB and receives detection light to generate a color workpiece image. The first image pickup section 50A includes a single-channel high-magnification-side image pickup element 55 and a single-channel low-magnification-side image pickup element 56. The image measuring section 3a is configured to measure the size of the workpiece W based on the workpiece image generated by the first image capturing section 50A.

The color information generating unit 3f generates color information of the workpiece W based on the workpiece image generated by the second imaging unit 50B. The control section 3d generates a color image obtained by adding the color information of the workpiece W generated by the color information generating section 3f to the grayscale workpiece image generated by the first image capturing section 50A. The display section 4 displays the color image generated by the control section 3d, and superimposes and displays the result of the size measurement in the image measurement section 3a on the color image.

The above embodiments are merely examples in all respects and should not be construed as limiting. Further, all modifications and changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

As described above, the present invention can be used to measure three-dimensional coordinates of a workpiece placed on a stage.

Claims

1. An image measurement apparatus comprising:

a rack for placing a workpiece;

a light projection section for irradiating a workpiece on the stage with detection light;

an imaging unit configured to receive the detection light and generate a workpiece image;

an image measuring section for measuring a size of the workpiece using the workpiece image generated by the image capturing section;

the touch detector is used for outputting a contact signal when the touch detector is in contact with a workpiece on the rack;

A driving part for moving at least one of the stage and the touch detector relative to the other to bring the touch detector into contact with a workpiece placed on the stage; and

a coordinate measuring section for measuring three-dimensional coordinates of a contact point of the touch detector with the workpiece based on a contact signal output when the touch detector is brought into contact with the workpiece by the driving section, the image measuring apparatus measuring a size of the workpiece based on a measurement result of at least one of the image measuring section and the coordinate measuring section,

wherein, the touch detector includes:

a housing;

a probe shaft having a rod shape and disposed inside the housing;

a stylus detachably attached to a distal end portion of the probe shaft and having a contact portion to be brought into contact with the workpiece;

a first elastic member connected to the housing and the probe shaft and forming a deflection fulcrum of the probe shaft;

a second elastic member that is connected to the housing and the probe shaft at a portion axially distant from the first elastic member, and returns the probe shaft to an origin; and

And a displacement detection mechanism for detecting a three-dimensional displacement of the probe shaft at a base end side of the probe shaft in a noncontact manner.

2. The image measurement device of claim 1, wherein the first elastic member is configured to have a stronger restraining force against displacement of the probe shaft in a radial direction than the second elastic member.

3. The image measurement device of claim 1, wherein the second elastic member is configured to have a stronger biasing force for biasing the probe shaft toward the origin point than the first elastic member.

4. The image measurement device according to claim 1, wherein the displacement detection mechanism is a magnetic sensor.

5. The image measurement device according to claim 1, wherein the displacement detection mechanism includes: a first displacement detection mechanism for detecting a displacement in a first direction extending along an axial direction of the probe shaft; a second displacement detection mechanism for detecting a displacement in a second direction extending in a radial direction of the probe shaft; and a third displacement detection mechanism for detecting a displacement in a third direction extending in a radial direction of the probe shaft and orthogonal to the second direction.

6. The image measuring apparatus according to claim 1, wherein the first elastic member is a leaf spring extending along an extension line in a radial direction of the probe shaft and having an outer end connected to the housing.

7. The image measuring device according to claim 1, wherein the second elastic member includes three or more extension springs extending radially from the probe shaft and having outer ends connected to the housing, and spring forces of the three or more extension springs are set to be balanced.

8. The image measuring apparatus according to claim 1, wherein damping grease for generating a damping force is applied to the second elastic member.

9. The image measurement device according to claim 1, wherein an attaching and detaching mechanism using a magnet is provided between the stylus and the probe shaft.

10. The image measuring apparatus according to claim 1, wherein,

the second elastic member is disposed closer to the distal end side of the probe shaft than the first elastic member, and

the displacement detection mechanism is disposed closer to a base end side of the probe shaft than the first elastic member.

11. A touch detector for outputting a contact signal when the touch detector is in contact with a workpiece on a gantry, the touch detector comprising:

a housing;

a probe shaft having a rod shape and disposed inside the housing;

a second elastic member that is connected to the housing and the probe shaft at a portion on an axis remote from the first elastic member, and returns the probe shaft swinging about the deflection fulcrum to an origin; and

and a displacement detection mechanism for detecting displacement of the probe shaft in a three-dimensional direction on a base end side of the probe shaft in a noncontact manner.