JP2007114106A - Displacement sensor and surface property measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement sensor for detecting minute displacement with high accuracy. <P>SOLUTION: Displacement of a gauge head 110 is enlarged by a displacement enlargement mechanism part 400 equipped with Eden spring mechanisms 411 to 448 while detecting this enlarged displacement by a displacement detection means 600 to detect the displacement amount and displacement direction of the gauge head 110. The spring mechanisms 411 to 448 are each structured by close placing two flat springs 310 and 320 in parallel. The mechanism part 400 includes the eight Eden spring mechanisms 411 to 448. The eight spring mechanisms 411 to 448 are disposed at equal spaces on the circumference of a circle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a displacement sensor and a surface texture measuring device. For example, the present invention relates to a displacement sensor that detects a displacement amount and a displacement direction of a probe.

Measuring devices that scan the surface of the object to be measured and measure the surface properties and three-dimensional shape of the object to be measured are known, such as a roughness measuring machine, a contour shape measuring machine, a roundness measuring machine, and a three-dimensional measuring machine. It has been known.
In such a measuring apparatus, a probe is used as a displacement sensor that detects the surface of the object to be measured based on the minute displacement of the contact part when the contact part contacts the surface of the object to be measured (Patent Document 1).
FIG. 15 shows a configuration of a shape measuring apparatus (surface texture measuring apparatus) 10 using a probe.
The shape measuring apparatus 10 includes a probe 11 and a drive mechanism 12 that moves the probe 11 three-dimensionally along the surface of the object to be measured.
As shown in FIG. 16, the probe 11 includes a stylus 13 having a contact portion 14 at the distal end and a main body portion 15 that supports the proximal end of the stylus 13. The main body 15 supports the stylus 13 so as to be displaceable within a certain range in the xp, yp, and zp directions, and detects the amount of displacement of the stylus 13.
In such a configuration, the probe 11 is moved along the surface of the object to be measured by the drive mechanism 12 in a state where the contact portion 14 is in contact with the surface of the object to be measured with the reference pressing amount Δr. At this time, the movement locus of the probe 11 is obtained from the drive amount of the drive mechanism 12, and the surface shape of the object to be measured is obtained from the movement locus of the probe 11.

JP 2000-39302 A

  However, since the resolution for detecting minute displacements is not necessarily high in the conventional probe 11, the pushing amount Δr is increased to a predetermined amount or more in order to reliably detect that the contact portion 14 has come into contact with the object to be measured. There must be. When the pressing amount Δr is increased in this way, the contact pressure with respect to the object to be measured increases, and when the contact portion is pressed against the surface of the object to be measured with a large contact pressure, the object to be measured is damaged.

  An object of the present invention is to provide a displacement sensor that detects a minute displacement with high accuracy and a shape measuring device including the displacement sensor.

  The displacement sensor of the present invention includes a measuring element and a sensor main body part that supports the measuring element so as to be displaceable and detects the displacement of the measuring element, and the sensor main body parts are arranged substantially parallel and close to each other. The distal ends of one longitudinal elastic member and the other longitudinal elastic member are connected to each other while maintaining a predetermined distance, and the base end of the one longitudinal elastic member is a free end, and the other longitudinal elastic member When the base end of the member is a fixed end and a displacement including a longitudinal direction displacement component occurs at the free end, the distal end portion exceeds the amount of displacement of the free end in a plane including the free end and the fixed end. A displacement enlarging mechanism having an Eden spring mechanism that swings and displaces, and a displacement detector that detects a displacement amount of the probe by detecting a displacement amount of the tip of the Eden spring mechanism. The enlargement mechanism has three or more A spring mechanism and supports the measuring element at all free ends of the three or more eden spring mechanisms, and the displacement detecting means includes a tip of all the Eden spring mechanisms when the measuring element is displaced. And a displacement amount and a displacement direction of the measuring element are detected based on a displacement amount of a tip portion of each Eden spring mechanism.

In such a configuration, since the probe is supported by the free end of the Eden spring mechanism, when the probe is displaced, the free end of the Eden spring mechanism is displaced.
Then, due to the displacement of the free end of the Eden spring mechanism, the tip of the Eden spring mechanism is displaced more than the displacement of the free end. At this time, when three or more Eden spring mechanisms are provided, the tip of each Eden spring mechanism exhibits different displacements depending on the displacement direction and displacement amount of the probe.
That is, in the Eden spring mechanism, the tip end portion is oscillated and displaced in a plane including the free end and the fixed end, and each Eden spring mechanism has a sensitive direction in the plane. Then, the displacement of the measuring element is decomposed in the sensitive direction of each Eden spring mechanism, and each Eden spring mechanism has a displacement at its tip according to the component in each sensitive direction. The displacement of the tip of each Eden spring mechanism is detected by a displacement detection means. The displacement of the tip of each Eden spring mechanism corresponds to a component obtained by disassembling the displacement of the probe in the sensitive direction of each Eden spring mechanism. Based on this, the displacement direction and displacement amount of the probe are obtained.

According to such a configuration, the displacement of the probe can be increased to a large displacement by the Eden spring mechanism, and the displacement of the probe can be detected by detecting the displacement of the tip of the Eden spring mechanism that has expanded the displacement of the probe. Can be improved. For example, since the displacement of the probe can be expanded several tens of times by the Eden spring mechanism, the detection resolution can be greatly improved.
Since the displacement of the probe is enlarged by the Eden spring mechanism, for example, even when the probe is brought into contact with the surface of the object to be measured and the surface of the object to be measured is detected, the contact pressure is so weak that the probe is slightly displaced. And the surface of the object to be measured is not damaged.

In addition, since the displacement enlarging mechanism section includes three or more Eden spring mechanisms, the displacement of the measuring element can be captured in three or more sensitive directions by the three or more Eden spring mechanisms. Therefore, the three-dimensional displacement direction and displacement amount of the measuring element can be specified.
Here, the displacement magnifying mechanism for enlarging the displacement of the measuring element includes three or more Eden spring mechanisms. The Eden spring mechanism has a simple configuration in which two longitudinal elastic members are close to each other, for example, a tooth wheel train. Since the component parts are small and very few rather than a complicated mechanism such as the above, the displacement magnifying mechanism can be extremely miniaturized.
For example, if the length of the elastic member constituting the Eden spring mechanism is about several tens of mm and the distance between the elastic members is about 0.1 mm to 0.5 mm, the displacement magnifying mechanism becomes extremely small, compared with a conventional displacement sensor. Although it has high resolution, it has an epoch-making effect that it can be miniaturized.

  In configuring the Eden spring mechanism, the ends of the two longitudinal elastic members may be directly bonded to each other, a coupling member may be sandwiched between the ends, A thin plate may be bent to form an Eden spring mechanism as one and the other longitudinal elastic member. Further, the longitudinal elastic member may be plate-shaped or linear.

  In the present invention, it is preferable that the three or more Eden spring mechanisms are arranged at equal intervals along the circumference of the virtual circle, and the measuring element is supported on an axis passing through the center of the virtual circle.

  According to such a configuration, since the three or more Eden spring mechanisms are arranged at equal distances around the measuring element and are equidistant, the three or more Eden spring mechanisms have no anisotropy. As a result, there is no error due to the detection direction when detecting the displacement of the probe, and the detection accuracy can be improved.

  In the present invention, the displacement magnifying mechanism section includes a parallel Eden spring mechanism configured by a combination of Eden spring mechanisms disposed at positions facing each other across the center of the virtual circle, and the parallel Eden spring mechanism has two different directions. It is preferable to exist in pairs or more.

  In such a configuration, since two eden spring mechanisms are arranged as a parallel eden spring mechanism in one plane, the displacement component in the plane can be detected with twice the amount of information. Further, since they face each other with the measuring element as the center, the two Eden spring mechanisms constituting the parallel Eden spring mechanism show different sensitivities to the displacement of the measuring element. Therefore, the displacement and displacement direction of the measuring element in the plane including the two Eden spring mechanisms of the parallel Eden spring mechanism can be uniquely determined from the displacement of each tip portion of each Eden spring mechanism of the parallel Eden spring mechanism. By providing two sets of the parallel Eden spring mechanisms in different directions, it is possible to capture the three-dimensional displacement of the probe.

In addition, when providing two sets of parallel Eden spring mechanisms, it is preferable to set it as orthogonal arrangement | positioning so that the line which ties each set of Eden spring mechanisms may mutually orthogonally cross.
According to such a configuration, the four eden spring mechanisms are arranged at intervals of 90 degrees, and thus the four eden spring mechanisms have no anisotropy. Since the displacement of the probe is decomposed into each component in the orthogonal direction, the displacement amount and the displacement direction of the probe can be easily obtained from the detection value by the displacement detector.

  In the present invention, it is preferable that the displacement magnifying mechanism unit includes four sets of the parallel Eden spring mechanisms, and a line connecting the two Eden spring mechanisms constituting the parallel Eden spring mechanism intersects at 45 degrees.

  In such a configuration, if there are two pairs of parallel eden spring mechanisms, the displacement amount and the displacement direction of the probe can be obtained sufficiently. By providing four pairs of parallel eden spring mechanisms, It is possible to double check the displacement amount and the displacement direction. Since the eight Eden spring mechanisms are arranged at equal intervals of 45 degrees, each Eden spring mechanism has no anisotropy. Therefore, an error due to the detection direction does not occur when detecting the displacement of the probe, and the detection accuracy can be improved.

  In the present invention, the sensor main body includes a housing that houses the displacement magnifying mechanism, and the displacement magnifying mechanism is an annular shape that surrounds the virtual circle and is fixed to the housing. A fixed portion, and a movable portion provided to be displaceable inside the virtual circle, wherein the three or more Eden spring mechanisms have the free end directed toward the center of the virtual circle and the fixed end directed to the virtual circle. The measuring element is arranged along the circumference of the virtual circle in a state of facing the outside of the circle, the free end is connected to the movable part, and the fixed end is connected to the fixed part. Is preferably fixed at a position corresponding to the center of the virtual circle in the movable part.

  In such a configuration, one base end of each Eden spring mechanism is connected to an annular (ring-shaped) fixed portion fixed to the housing, and the other base end of the Eden spring mechanism is connected to a movable portion that can be displaced. By connecting, one base end of the Eden spring mechanism can be a fixed end and the other base end can be a free end. Then, the Eden spring mechanism can be arranged in a circle centered on the measuring element by attaching the measuring element to the movable part arranged inside the virtual circle in which the Eden spring mechanism is arranged. When the measuring element is displaced, the movable part is displaced together with the measuring element. Then, the free end of each Eden spring mechanism connected to the movable part is displaced. Due to the displacement of the free end, the tip of each Eden spring mechanism is greatly displaced. Further, the displacement and the direction of displacement of the measuring element can be obtained by detecting the displacement of the tip of each Eden spring mechanism by the displacement detecting means.

  It should be noted that the fixed part is arranged outside the virtual circle and the movable part is arranged inside the virtual circle so that the fixed end of the Eden spring mechanism faces the outside of the virtual circle and the free end faces the inside of the virtual circle. The reverse is also possible. In other words, the fixed part is arranged inside the virtual circle and the ring-like movable part is arranged outside the virtual circle, the fixed end of the Eden spring mechanism is fixed to the inner fixed part, and the free end is changed to the outer movable part. You may connect. Then, for example, the probe may be supported via a beam attached to a ring-shaped movable part so that the axis of the probe passes through the center of the virtual circle. The larger the radius of the movable part, the larger the swinging displacement of the movable part with respect to the displacement of the probe, so the free end of the Eden spring mechanism is displaced by that much, and as a result, the displacement of the tip part of the Eden spring mechanism is also increased. Detection sensitivity is improved.

  In the present invention, the measuring element includes a stylus having a contact portion at a tip, and the Eden spring mechanism is arranged in a state in which a longitudinal direction thereof is oriented within 45 degrees with respect to an axial direction of the stylus in a reference state. It is preferable to be provided.

According to such a configuration, since the longitudinal direction of the Eden spring mechanism is within 45 degrees from the axial direction of the stylus, the displacement sensor can be configured to be vertically long along the axial direction of the stylus.
Here, the direction along the stylus axis is defined as the Z direction, and the plane orthogonal to the stylus axial direction is defined as the XY plane.
When the Eden spring mechanism is parallel to the stylus axis, the sensitivity of the contact portion with respect to the Z direction displacement is greater than the sensitivity of the contact portion with respect to the X direction (Y direction) displacement, and the sensitivity with respect to the Z direction displacement and the X direction (Y direction) ) Sensitivity to displacement is proportional to the radius r of the virtual circle. For this reason, when the displacement sensor is downsized, the radius r of the virtual circle in which the Eden spring mechanism is disposed is reduced, and thus the sensitivity to the displacement of the contact portion in the X direction (Y direction) is reduced.
Here, the sensitivity to the X direction (Y direction) displacement of the contact portion can be increased by increasing the angle of the Eden spring mechanism with respect to the axial direction of the stylus toward 45 degrees. Therefore, by appropriately setting the angle formed by the Eden spring mechanism and the stylus axis within 45 degrees, it is possible to optimally select the sensitivity to the Z-direction displacement and the sensitivity to the X-direction (Y-direction) displacement of the contact portion.

  If the angle between the eden spring mechanism and the stylus axis exceeds 45 degrees, the sensitivity to displacement in the X direction (Y direction) decreases, but the eden spring mechanism should be disposed at 45 degrees or more with respect to the stylus axis. However, the degree of freedom in designing the displacement sensor is improved by freely selecting the angle at which the Eden spring mechanism is disposed.

  Here, the axial direction of the stylus in the reference state means the axial direction of the stylus in a state where the displacement of the contact portion is zero.

  In the present invention, it is preferable that the Eden spring mechanism is disposed in parallel with the axial direction of the stylus in a reference state.

  According to such a configuration, since the Eden spring mechanism is arranged in parallel to the stylus axis direction, the displacement sensor can be configured to be vertically long along the stylus axis.

  In the present invention, it is preferable that the Eden spring mechanism is disposed in a state in which a longitudinal direction thereof is oriented in a direction that forms an angle of 45 degrees with respect to the axis of the stylus in a reference state.

In such a configuration, since the Eden spring mechanism is disposed at 45 degrees with respect to the stylus axis direction, the displacement of the contact portion in the X direction (Y direction) is smaller than when the Eden spring mechanism is disposed in parallel with the stylus axis direction. The sensitivity to is improved.
According to such a configuration, the sensitivity to the X direction (Y direction) displacement of the contact portion can be improved while keeping the radius r of the virtual circle in which the Eden spring mechanism is disposed small, so the X direction (Y direction). A small displacement sensor having high sensitivity to displacement can be obtained.

  In this invention, it is preferable that the said displacement detection means is provided with the movable electrode provided in the front-end | tip part of the said Eden spring mechanism, and displaced with the said front-end | tip part, and the fixed electrode provided facing the said movable electrode.

In such a configuration, when the tip of the Eden spring mechanism is displaced corresponding to the displacement of the probe, the distance between the movable electrode provided at the tip and the fixed electrode facing the movable electrode changes. The potential of the electrode changes.
Therefore, the displacement of the tip of the Eden spring mechanism can be detected by detecting the potential of each electrode.
In detecting the displacement of the tip portion of the Eden spring mechanism, it is only necessary to provide a fixed electrode so as to face the tip portion of each Eden spring mechanism. Therefore, the displacement detection means has a small number of components and is extremely miniaturized. As a result, a very small displacement sensor can be obtained.

  Here, when the Eden spring mechanism is composed of a metal thin plate, the metal thin plate may be used as a movable electrode as it is. Further, the fixed electrode may be a metal thin film formed by vapor deposition in addition to the plate-like electrode. Then, two fixed electrodes may be provided as fixed electrodes, and the two fixed electrodes may be disposed on opposite sides of each other with the tip portion of the Eden spring mechanism interposed therebetween.

  In the present invention, the displacement detection means includes an illumination optical system that irradiates light at the tip of the Eden spring mechanism, and an optical that is provided at the tip of each of the Eden spring mechanisms and reflects or refracts light from the illumination optical system. It is preferable to include an element and an optical sensor that is disposed at a predetermined distance from the optical element and detects a position where light from the optical element is incident two-dimensionally.

  In such a configuration, light is emitted from the illumination optical system toward the tip of the Eden spring mechanism. Then, this light is reflected or refracted by an optical element provided at the tip of the Eden spring mechanism. Here, when the tip portion of the Eden spring mechanism is displaced, the optical element is displaced together with the tip portion, so that the reflection or refraction direction of light changes. Then, light from the optical element is detected by an optical sensor. At this time, the optical sensor detects the incident position of the light, and detects the displacement of the tip portion of the Eden spring mechanism by the change of the incident position of the light.

  According to such a configuration, the displacement of the tip portion of the Eden spring mechanism can be enlarged and detected by the “optical lever”. That is, when the tip of the Eden spring mechanism is oscillated and displaced by an angle φ, the reflection or refraction direction of light by the optical element provided at the tip changes by 2φ, which is twice the displacement angle φ of the tip. And the incident position of the light to an optical sensor changes a lot by making the distance of an optical element and an optical sensor into predetermined length. In this way, in addition to the displacement of the stylus being expanded to a large displacement at the tip by the Eden spring mechanism, the displacement at the tip is further magnified by the “optical lever”, so the detection resolution is epoch-making Be improved.

Here, the optical element and the optical sensor are preferably separated as much as possible. For example, even if the length of the Eden spring mechanism is shortened, it is better to make the distance from the optical element to the optical sensor longer, and the distance from the optical element to the optical sensor is longer than the length of the Eden spring mechanism. As mentioned.
Increasing the length of the Eden spring mechanism increases the amount of displacement at the tip of the Eden spring mechanism, but the light reflection or refraction direction at the optical element changes by twice the angular displacement of the tip. Therefore, when the distance from the optical element to the optical sensor is made longer than the Eden spring mechanism is made longer, the incident position of the light on the optical sensor changes greatly.

  In the present invention, the illumination optical system includes one light emitting unit that emits light, a collimator lens that converts a light beam from the light emitting unit into a parallel light beam, and a thin light beam that is disposed in the next stage of the collimator lens. An aperture plate having a small-diameter aperture corresponding to the number of the Eden spring mechanisms; and a polyhedral prism having a facet that reflects each fine light beam that has passed through the aperture toward the optical element. Is preferred.

  In such a configuration, the light emitted from one light emitting means is made into a parallel light beam by the collimator lens and enters the aperture plate. Of the light incident on the aperture plate, fine light beams that have passed through the aperture with a small diameter enter the polyhedral prism. The fine light beam reflected by the polyhedral prism is reflected or refracted by an optical element provided at the tip of the Eden spring mechanism and received by the optical sensor.

According to such a configuration, since there is one light emitting means, the number of parts can be reduced as compared with, for example, providing light sources by the number of Eden spring mechanisms.
In addition, in the optical sensor, it is necessary to detect the change in the incident position of the light. However, the light incident on the optical sensor is incident in a spot shape, and the incident point must be detected by the optical sensor. In the invention, the light is made to enter the optical sensor as a fine light beam by narrowing the light with a small-diameter aperture, so that the change of the incident position of the light can be detected by the optical sensor.

  In the present invention, the illumination optical system includes one light emitting unit that emits light, a condensing lens that focuses the light from the light emitting unit to form an image, and the light from the condensing lens. It is preferable that the condensing lens forms an image of light on a sensor surface of the photosensor.

  In such a configuration, the light emitted from the one light emitting means enters the polyhedral prism through the condenser lens. Then, the light reflected toward the tip of each Eden spring mechanism by the polyhedral prism is reflected or refracted by an optical element provided at the tip of the Eden spring mechanism, and is received by the optical sensor.

According to such a configuration, since there is one light emitting means, the number of parts can be reduced as compared with providing light sources by the number of Eden spring mechanisms, for example.
In addition, in the optical sensor, it is necessary to detect the change in the incident position of the light. However, the light incident on the optical sensor is incident in a spot shape, and the incident point must be detected by the optical sensor. Since the light from the emitting means forms an image on the sensor surface of the optical sensor by the condenser lens, a change in the incident position of the light can be detected by the optical sensor.
In addition, since the light from the light emitting means is imaged by the condenser lens so that the light is incident on the optical sensor in a spot shape, for example, the light loss is reduced as compared with the case where the light beam is narrowed by an aperture to be a fine light beam. can do.

  In the present invention, the illumination optical system is disposed so that its optical axis substantially coincides with the axis of the measuring element, and the optical sensor extends from the tip of the Eden spring mechanism along the axial direction of the measuring element. It is preferable that they are disposed at positions separated by a predetermined distance.

  In such a configuration, for example, the components of the illumination optical system are arranged along the axis of the stylus so that the optical axis of the illumination optical system coincides with the axial direction of the stylus. Since the tip of the mechanism is disposed in the axial direction of the probe, the displacement sensor can be configured to be vertically long along the axial direction of the probe.

When three or more Eden spring mechanisms are arranged in a circle on the circumference of the virtual circle, the illumination optical system is preferably arranged inside the Eden spring mechanism arranged in a circle.
According to such a configuration, the space enclosed by the Eden spring mechanism can be effectively used, and the displacement sensor can be reduced in size.

  In the present invention, it is preferable that the measuring element includes a stylus having a contact portion at a tip, and the displacement detection unit includes a swing fulcrum fixing unit that fixes a swing fulcrum of the contact unit.

In such a configuration, the swing fulcrum of the measuring element is fixed by the swing fulcrum fixing means. Here, when the swing fulcrum of the probe is not structurally fixed, the probe is supported by the free end of the Eden spring mechanism, so that the swing fulcrum of the probe is changed depending on the strength of the elastic member constituting the Eden spring mechanism. It will be decided.
However, if the swing fulcrum is not known, the displacement amount of the contact portion cannot be calculated based on the displacement of the tip portion of the Eden spring mechanism.
In this respect, in the present invention, the swing fulcrum of the probe is structurally fixed, so that the displacement of the contact portion can be calculated from the displacement of the tip portion of the Eden spring mechanism.
If the swing fulcrum of the contact part varies depending on the strength of the Eden spring mechanism, an equation for calculating the displacement of the contact part from the displacement of the tip of the Eden spring mechanism is created for each product according to the position of the swing fulcrum. However, considering the production of a huge number of products, it is impossible to inspect each of the assembled products to find the swing fulcrum.
In this respect, in this embodiment, since the swing fulcrum is fixed, the same calculation formula and parameters can be used for all products, which is convenient.

  In the present invention, it is preferable that the swing fulcrum fixing means includes a fixed sphere that is substantially fixed at a predetermined position on the axis of the stylus, and the measuring element swings using the fixed sphere as a swing fulcrum.

According to such a configuration, the probe swings around the fixed ball as a fulcrum.
At this time, since the fulcrum is a sphere, the oscillating direction of the measuring element is not limited to, for example, one plane, and the measuring element can be freely oscillated and displaced in all directions.

  In the present invention, the three or more Eden spring mechanisms are arranged at equal intervals along the circumference of the virtual circle, and the displacement magnifying mechanism includes a movable portion provided to be displaceable inside the virtual circle, and The free end of the Eden spring mechanism is coupled to the movable part, and the displacement of the fixed sphere in the direction intersecting the axis of the probe at the center of the virtual circle is restricted, and the axis of the probe The displacement along the direction is substantially fixed in an allowable state, the measuring element is fixed at a position corresponding to the center of the virtual circle in the movable portion, and the movable portion is positioned at the center of the virtual circle. It is preferable to contact the fixed ball at the corresponding position.

  In such a configuration, when the probe is displaced in a direction (X direction or Y direction) orthogonal to the axial direction of the probe, the movable part is displaced together with the probe. At this time, since the movable portion is in contact with the fixed sphere, the movable portion swings with the fixed sphere as a fulcrum. Since the free end of the Eden spring mechanism connected to the movable part is displaced by the swinging of the movable part, the tip of the Eden spring mechanism is greatly displaced. The displacement of the tip of the Eden spring mechanism is detected by a displacement detector. Further, when the measuring element is displaced in the axial direction (Z direction) of the measuring element, the movable part is displaced in the axial direction of the measuring element together with the measuring element. At this time, the displacement of the fixed sphere in the axial direction of the probe is allowed. Since the free end of the Eden spring mechanism is displaced along with the displacement of the movable part, the tip of the Eden spring mechanism is greatly displaced.

According to such a configuration, the movable part abuts on the fixed sphere and the fulcrum of the swing is fixed. Therefore, when the probe is displaced in the X direction (or Y direction), the movable part swings with the fixed sphere as the fulcrum. Move. At this time, the center of the movable part is not displaced in the Z direction. On the other hand, when the probe is displaced in the Z direction, the movable part is displaced in the Z direction.
For example, when the swing fulcrum of the probe is not fixed, the swing fulcrum is determined at some point on the axis of the probe depending on the strength of the Eden spring mechanism that supports the probe. If they do not coincide with each other, the movable part (center thereof) is displaced in the Z direction by the swinging of the probe with the swinging fulcrum as a fulcrum.
Thus, when the movable part (the center) is displaced in the Z direction by the swinging of the contact part,
Complicated calculation is required to calculate the displacement of the probe from the displacement of the tip of the Eden spring mechanism.
In this regard, in the present invention, as long as the contact portion is displaced in the X direction (or Y direction), the center of the movable portion is not displaced in the Z direction, and only when the probe is displaced in the Z direction, the movable portion ( Center) is displaced in the Z direction. That is, the displacement of the probe in the Z direction and the displacement in the X direction are clearly separated.

  It is preferable that a conical hole is formed in the movable part so that the movable part is not displaced with respect to the fixed sphere, and the fixed sphere is slidably fitted into the hole.

  In the present invention, it is preferable that a braking means for braking the vibration of the Eden spring mechanism is provided.

  In such a configuration, the Eden spring mechanism is composed of a longitudinal elastic member. However, there is a possibility that the Eden spring mechanism may vibrate finely when the probe is displaced or due to vibration applied from the outside. In this regard, in the present invention, since the vibration of the Eden spring mechanism can be suppressed by the braking means, the detection error due to the vibration of the Eden spring mechanism can be eliminated and the detection accuracy can be improved.

  In the present invention, the braking means is disposed in proximity to the conductive plate, and a conductive plate protruding from the one or the other longitudinal elastic member in a direction crossing the longitudinal direction of the Eden spring mechanism. And a magnet.

  In such a configuration, when the Eden spring mechanism is bent, the conductive plate is displaced together with the Eden spring mechanism. At this time, since the conductive plate is arranged close to the magnet, an eddy current is generated in the conductive plate due to the movement of the conductive plate. And, by this eddy current and the magnetic flux of the magnet, a braking force opposite to the moving direction of the conductive plate acts on the conductive plate. Since the fluctuation of the conductive plate is suppressed by this braking force, the braking force acts on the Eden spring mechanism. Since only the conductive plate and the magnet are used as the braking means, the configuration is simple, and the displacement sensor can be very downsized while having the braking function of the Eden spring mechanism.

  The surface texture measuring apparatus according to the present invention includes the displacement sensor, a drive mechanism that moves the displacement sensor relative to the object to be measured to bring the displacement sensor into contact with the surface of the object to be measured, and a displacement by the drive mechanism. A driving sensor that detects a relative displacement amount between the sensor and the object to be measured; and an analysis unit that analyzes a shape of the object to be measured based on a value detected by the displacement sensor and the driving sensor. To do.

  In such a configuration, the surface of the object to be measured can be detected by bringing the probe of the displacement sensor into contact with the surface of the object to be measured. In addition, for example, the displacement sensor is moved along the surface of the object to be measured by the drive mechanism in a state where the measuring element of the displacement sensor is pushed into the surface of the object to be measured by a predetermined pushing amount, and the measurement is performed from the path of the displacement sensor. The surface shape of an object can be measured.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be illustrated and described with reference to reference numerals attached to respective elements in the drawings.
(First embodiment)
A first embodiment according to the displacement sensor of the present invention will be described.
FIG. 1 is a cross-sectional view of the first embodiment cut in the vertical direction.
FIG. 2 is a longitudinal sectional view taken along line II-II in FIG.
FIG. 3 is a perspective view showing the configuration of the displacement magnifying mechanism 400.

  Here, for convenience of explanation, the vertical direction in FIG. 1 is the Z direction, and the horizontal direction in FIG. 1 is the X direction.

  The displacement sensor 100 includes a measuring element 110 that is displaced by contact pressure when it contacts the surface of the object to be measured, and a sensor main body 200 that supports the measuring element 110 so as to be displaceable and detects the displacement of the measuring element 110. .

  The measuring element 110 includes a stylus 120 and a contact portion 130 provided at the tip of the stylus 120. The base end of the stylus 120 is attached to the sensor main body 200, and the measuring element 110 is supported in a state of hanging from the sensor main body 200.

  The sensor body 200 includes a cylindrical housing 210 having a lower end opened and a storage space 211 therein, and eden spring mechanisms 411 to 448 that expand a minute displacement of the free end 311 to a large displacement of the tip 340. The displacement of the probe 110 is detected by detecting the amount of displacement of the displacement magnifying mechanism 400 that expands the displacement of the probe 110 to a large displacement of the tip 340 of the Eden spring mechanism 411 to 448 and the tip 340 of the Eden spring mechanism 300. Displacement detecting means 600, and braking means 700 for braking the vibration of the Eden spring mechanism.

  The housing part 210 houses the displacement enlarging mechanism part 400, the displacement detection means 600 and the braking means 700 in the internal storage space 211. A top plate 212 is provided at the upper end of the housing part 210, and a signal extraction hole 213 through which a predetermined signal line is drawn is formed in the top plate 212.

  The displacement enlarging mechanism unit 400 is an annular shape in which eight Eden spring mechanisms 411 to 448 arranged at equal intervals on the circumference of the virtual circle C shown in FIG. 2 or FIG. 3 and a fixed end 321 of the Eden spring mechanism are connected. The fixed portion 450 and a movable portion 460 to which the free end 311 of the Eden spring mechanism is coupled.

The Eden spring mechanism 411 to 448 will be described.
The Eden spring mechanisms 411 to 448 include a first leaf spring 310 and a second leaf spring 320 that are longitudinal leaf springs (longitudinal elastic members).
The first leaf spring 310 and the second leaf spring 320 are parallel to each other and arranged in close proximity. The length b of the first and second leaf springs 310 and 320 is about 10 mm (see FIG. 7), and the distance a between the first leaf spring 310 and the second leaf spring 320 is, for example, about 0.1 mm to 0.4 mm. It is. The Eden spring mechanism is formed of a single metal plate. The middle of the single metal plate is bent into a first plate spring 310 and a second plate spring 320, and the bent portion is bent in two stages to form a right angle. A predetermined gap a is maintained between the first leaf spring 310 and the second leaf spring 320 by forming two corners.

  In the displacement enlarging mechanism 400, as shown in FIG. 3, the eight eden spring mechanisms 411 to 448 are arranged at equal intervals on the circumference of the virtual circle C having a predetermined radius r. As shown in FIG. 2, the virtual circle C is a circle on the XY plane and has its center on the stylus axis of the probe 110. As shown in FIG. 3, the Eden spring mechanisms 411 to 448 are arranged with the first leaf spring 310 facing the inside of the virtual circle C and the second leaf spring 320 facing the outside of the virtual circle C.

  Further, the Eden spring mechanism is disposed with the base end side as the opening end side (lower end surface side) of the housing portion 210 and the tip end 340 side as the top plate 212 side. That is, the Eden spring mechanisms 411 to 448 are arranged in parallel with the Z direction with the distal end portion 340 in the upper side and the base end side in the lower side in FIG. 1, and the longitudinal direction of the Eden spring mechanisms 411 to 448 is the stylus. It is parallel to 120 axial directions.

  Here, the eight eden spring mechanisms 411 to 448 are arranged at equal intervals on the circumference of the virtual circle C, and the two Eden spring mechanisms 411 to 448 are in a point-symmetrical group with the center of the virtual circle C as the center of point symmetry. Parallel Eden spring mechanisms 410 to 440 are configured. That is, the displacement magnifying mechanism 400 includes four sets of parallel Eden spring mechanisms 410 to 440 (see FIG. 2). The lines connecting the two Eden spring mechanisms of each set 410 to 440 intersect at 45 degrees.

  Here, in FIG. 2, the vertical direction on the paper is the Y direction, and the horizontal direction on the paper is the X direction.

  The Eden spring mechanism disposed in the + X direction is referred to as a first Eden spring mechanism 411, and the second Eden spring mechanism 422, the third Eden spring mechanism 433, the fourth Eden spring mechanism 444, the fifth Eden spring mechanism 415, in that order, from there. A sixth Eden spring mechanism 426, a seventh Eden spring mechanism 437, and an eighth Eden spring mechanism 448 are provided.

A parallel Eden spring mechanism constituted by a first Eden spring mechanism 411 and a fifth Eden spring mechanism 415 that are two Eden spring mechanisms arranged in the X direction is referred to as a first parallel Eden spring mechanism 410.
A parallel Eden spring mechanism constituted by a second Eden spring mechanism 422 and a sixth Eden spring mechanism 426 which are two Eden spring mechanisms arranged in the +45 degree direction is referred to as a second parallel Eden spring mechanism 420.
A parallel Eden spring mechanism constituted by a third Eden spring mechanism 433 and a seventh Eden spring mechanism 437 which are two Eden spring mechanisms arranged in the Y direction is referred to as a third parallel Eden spring mechanism 430.
A parallel Eden spring mechanism constituted by a fourth Eden spring mechanism 444 and an eighth Eden spring mechanism 448 which are two Eden spring mechanisms arranged in the −45 degree direction is referred to as a fourth parallel Eden spring mechanism 440.

  The fixing portion 450 is a ring-shaped member, and the ring diameter is slightly larger than the diameter r of the virtual circle C in which the Eden spring mechanisms 411 to 448 are disposed. The fixing portion 450 is attached and fixed to the lower end opening edge 214 on the lower end side where the housing portion 210 is opened. And the base end of the 2nd leaf | plate spring 320 of each Eden spring mechanism 411-448 is attached and fixed to the fixing | fixed part 450. As shown in FIG. Here, the base end of the second leaf spring 320 becomes the fixed end 321.

  The movable portion 460 is slightly smaller than the diameter of the virtual circle C where the Eden spring mechanisms 411 to 448 are disposed, and is disposed in the ring of the annular fixed portion 450. And the base end of the 1st leaf | plate spring 310 of each Eden spring mechanism 411-448 is attached and fixed to the movable part 460. As shown in FIG. Here, the base end of the first leaf spring 310 becomes the free end 311. The base end portion of the stylus 120 is provided at a position corresponding to the center of the virtual circle C in the movable portion 460.

The displacement detection unit 600 includes eight capacitor units 611 to 648 corresponding to the eight eden spring mechanisms 411 to 448 and a signal processing unit 650 that performs signal processing on detection signals from the capacitor units 611 to 648.
The capacitor portions 611 to 648 are a set of two fixed electrodes disposed on opposite sides of the movable electrode that is the tip portion 340 of the Eden spring mechanism 411 to 448 and the tip portion 340 of the Eden spring mechanism 411 to 448. A three-pole capacitor including an electrode set 520.

The fixed electrode set 520 includes an outer fixed electrode 521 disposed outside the circle and an inner fixed electrode 522 disposed inside the circle with respect to the Eden spring mechanisms 411 to 448 disposed in a circle. .
The outer fixed electrode 521 is attached and fixed to the inner wall surface of the housing part 210.
Further, a cylindrical inner cylinder portion 215 is attached to the top plate 212 so as to hang down, and the inner fixed electrode 522 is attached and fixed to the outer surface of the inner cylinder portion 215.
The ground wire 511 is drawn from the Eden spring mechanisms 411 to 448, and the potentials of the Eden spring mechanisms 411 to 448 are zero. Further, signal lead lines 523 are led out from the outer fixed electrode 521 and the inner fixed electrode 522, respectively.

  Here, the capacitor portion corresponding to the first Eden spring mechanism 411 is referred to as a first capacitor portion 611, the capacitor portion corresponding to the second Eden spring mechanism 422 is referred to as a second capacitor portion 622, and the capacitor portion corresponding to the third Eden spring mechanism 433 is referred to as a capacitor portion. The third capacitor portion 633, the capacitor portion corresponding to the fourth Eden spring mechanism 444 is the fourth capacitor portion 644, the capacitor portion corresponding to the fifth Eden spring mechanism 415 is the fifth capacitor portion 615, and corresponds to the sixth Eden spring mechanism 426. The capacitor portion to be used is the sixth capacitor portion 626, the capacitor portion corresponding to the seventh Eden spring mechanism 437 is the seventh capacitor portion 637, and the capacitor portion corresponding to the eighth Eden spring mechanism 448 is the eighth capacitor portion 648.

  In addition, a combination of the first capacitor unit 611 and the fifth capacitor unit 615 corresponding to the first parallel Eden spring mechanism 410 is referred to as a first capacitor combination 610. Similarly, the second parallel Eden spring mechanism 420 corresponds to the second parallel Eden spring mechanism 420. A set of the capacitor unit 622 and the sixth capacitor unit 626 is referred to as a second capacitor combination 620, and a set of the third capacitor unit 633 and the seventh capacitor unit 637 corresponding to the third parallel Eden spring mechanism 430 is combined with the third capacitor combination 630. Corresponding to the fourth parallel Eden spring mechanism 440, the combination of the fourth capacitor portion 644 and the eighth capacitor portion 648 is referred to as a fourth capacitor combination 640.

  Ground wires 511 from the Eden spring mechanisms 411 to 448 and signal lead lines 523 from the capacitor units 611 to 648 are connected to the signal processing unit 650.

A signal detected by each capacitor when the tip of the Eden spring mechanism is displaced is as follows.
Here, the detection signal from the nth capacitor unit is Sn (n is 1 to 8), the signal of the outer fixed electrode 521 is Pn1, the signal of the inner fixed electrode 522 is Pn2, and the potential of the Eden spring mechanism is G.

And the detection signal H by each capacitor | condenser combination 610-640 is represented by the following formula | equation.
Here, the detection signal from the first capacitor combination 610 is H1, the detection signal from the second capacitor combination 620 is H2, the detection signal from the third capacitor combination 630 is H3, and the detection signal from the fourth capacitor combination 640 is H4.

  In addition, when the contact part 130 is specifically displaced to the predetermined direction, the signal output from each capacitor | condenser part 611-648 is demonstrated in description of operation | movement.

The braking means 700 includes a conductive plate 710 protruding in the middle of the first plate spring 310 and two magnets disposed on opposite sides with the conductive plate 710 in between.
The conductive plate 710 protrudes from the first plate spring 310 toward the center line I.
The center line I is a line that coincides with the axial direction of the stylus 120 in the reference state and passes through the center of the virtual circle C. The first magnet 720 is attached and fixed to the lower end of the inner cylinder portion 215, and the second magnet 730 is fixed by a thin plate-like connecting member 740 interposed between the first magnet 720 and the first magnet 720.

The operation of the first embodiment having such a configuration will be described.
First, an operation in which the displacement of the contact portion 130 is expanded by the Eden spring mechanism of the displacement magnifying mechanism portion 400 when the contact portion 130 is displaced in contact with the surface of the object to be measured will be described.

4 to 8 are diagrams for explaining a mechanism in which the displacement of the contact portion 130 is enlarged by the Eden spring mechanisms 411 to 448.
4, 5, and 6 are diagrams illustrating different patterns of deformation of the first parallel Eden spring mechanism 410 that are generated depending on the direction in which the first parallel Eden spring mechanism 410 is extracted and the contact portion 130 is displaced.
The vertical direction of the paper surface in FIG. 4 is the Z direction, the horizontal direction of the paper surface is the X direction, and the direction perpendicular to the paper surface is the Y direction.

FIG. 4 is a diagram illustrating a change in the first parallel Eden spring mechanism 410 when the contact portion 130 is displaced upward (+ Z direction).
FIG. 5 is a diagram illustrating a change in the first parallel Eden spring mechanism 410 when the contact portion 130 is displaced downward (−Z direction).
FIG. 6 is a diagram illustrating a change in the first parallel Eden spring mechanism 410 when the contact portion 130 is displaced in the lateral direction (+ X direction).

  In the first parallel Eden spring mechanism 410, when the contact portion 130 is displaced in a plane including the two Eden spring mechanisms constituting the first parallel Eden spring mechanism 410, each of the Eden spring mechanisms 411, 415 is changed according to the displacement of the contact portion 130. The tip 340 is displaced. In FIG. 4, the fixed end 321 of the first parallel Eden spring mechanism 410 is fixed to the fixed part 450, the free end 311 is connected to the movable part 460, and the measuring element 110 is supported by the movable part 460.

  When the contact part 130 is displaced upward (+ Z direction), the movable part 460 is displaced upward (+ Z direction) together with the measuring element 110, so that the free ends 311 of the first and fifth Eden spring mechanisms 411, 415 are upward. Displacement (+ Z direction). Then, the distal end portion 340 of the first Eden spring mechanism 411 and the distal end portion 340 of the fifth Eden spring mechanism 415 are displaced in the lateral direction (X direction) so as to be separated from each other. That is, the distal end portion 340 of the first Eden spring mechanism 411 is displaced in the + X direction, and the distal end portion 340 of the fifth Eden spring mechanism 415 is displaced in the −X direction.

  In FIG. 5, when the contact part 130 is displaced downward (−Z direction), the movable part 460 is displaced downward (−Z direction) together with the measuring element 110, so that the first and fifth Eden spring mechanisms 411 and 415 are free. The end 311 is displaced downward (−Z direction). Then, the distal end portion 340 of the first eden spring mechanism 411 and the distal end portion 340 of the fifth eden spring mechanism 415 are displaced in the lateral direction (X direction) in a direction close to each other. That is, the distal end portion 340 of the first Eden spring mechanism 411 is displaced in the −X direction, and the distal end portion 340 of the fifth Eden spring mechanism 415 is displaced in the + X direction.

In FIG. 6, the case where the contact part 130 is displaced in the + X direction will be described.
When the contact part 130 is displaced in the + X direction, the stylus 120 swings. At this time, the stylus 120 is supported by the free ends 311 of the first and fifth Eden spring mechanisms 411 and 415 via the movable part 460. The fulcrum of the swing of the contact part 130 is the strength of the Eden spring mechanisms 411 and 415. Determined by.
In FIG. 6, the swing fulcrum 811 is illustrated as being present on the center line I between the movable portion 460 and the tip portions 340 of the Eden spring mechanisms 411 and 415.
Since the stylus 120 swings due to the lateral displacement of the contact part 130, the movable part 460 also swings and displaces.
At this time, since the contact part 130 is displaced in the + X direction, the + X direction side end of the movable part 460 is displaced upward, and the −X direction end is displaced downward. Then, the free end 311 of the first Eden spring mechanism 411 is displaced upward (+ Z direction), and the distal end portion 340 of the first Eden spring mechanism 411 is displaced in the + X direction. Further, the free end 311 of the second Eden spring mechanism 422 is displaced downward (−Z direction), and the distal end portion 340 of the second Eden spring mechanism 422 is displaced in the + X direction. That is, when the contact portion 130 is displaced in the lateral direction (X direction), the two tip portions 340 of the parallel Eden spring mechanism 410 are both displaced in the same direction as the contact portion 130.

Here, FIG. 7 shows an enlarged view of a state in which the tip 340 of the Eden spring mechanism is displaced.
When the free end 311 is displaced upward (+ Z direction), a stress that displaces the free end 311 upward is transmitted from the tip of the first leaf spring 310 to the tip of the second leaf spring 320. Since the base end portion of the second leaf spring 320 is fixed as the fixed end 321, the distal end portion 340 is oscillated and displaced with the fixed end 321 as a fulcrum. ). The swing angle φ of the tip 340 at this time is expressed as “φ = Δz / a”, where Δz is the displacement of the free end 311 and a is the distance between the first leaf spring 310 and the second leaf spring 320. Is done.

Further, a cantilever 490 is shown in FIG. 8 in contrast to the Eden spring mechanism of FIG.
In FIG. 8, when the tip 492 of the leaf spring 491 of the cantilever 490 is displaced by Δx, if the length of the leaf spring 491 is b, the swing angle φ ′ of the tip 340 is “φ ′ = 3Δx. / 2b ".

  For example, the displacement amount Δz of the free end 311 and the displacement Δx of the tip 492 of the cantilever 490 are set to 0.001 mm, the length b of the leaf springs 310, 320, and 491 is set to 10 mm, and the first leaf spring 310 and the second plate If the distance a from the spring 320 is 0.1 mm, the swing angle φ of the tip 340 of the Eden spring mechanism 411 is 67 times the swing angle φ ′ of the tip 492 of the cantilever 490. That is, the Eden spring mechanism 411 expands the minute displacement of the free end 311 as a large swing displacement of the tip 340.

  Next, in the displacement sensor 100 of the first embodiment, an operation of detecting the displacement of the contact portion 130 by the displacement detection means 600 when the contact portion 130 is displaced by contacting the surface of the object to be measured will be described.

  When the contact part 130 comes into contact with the surface of the object to be measured and is displaced, the tip part 340 of the Eden spring mechanism 411 to 448 is displaced. The displacement of the tip 340 of the Eden spring mechanisms 411 to 448 is as shown in FIGS. The tip part 340 of the Eden spring mechanism 411 to 448 is a movable electrode of the capacitor part 611 to 648. The displacement of the movable electrode is caused by two fixed electrodes 521 sandwiching the tip part 340 of the Eden spring mechanism 411 to 448. 522.

  First, a signal detected by the displacement detection unit 600 when the contact portion 130 is displaced by ΔZ in the Z direction and by ΔR in the θ direction within the XY plane (see FIG. 2) will be described.

  A detection signal Ez detected by the displacement detection means 600 corresponding to the ΔZ displacement of the contact portion 130 is expressed by the following equation.

  Ez = {(S1 + S5) + (S2 + S6) + (S3 + S7) + (S4 + S8)} / 4 = (H1 + H2 + H3 + H4) / 4

  Next, the detection signals H1 to H4 in the first to fourth capacitor combinations 610 to 640 with respect to the ΔR displacement of the contact portion 130 will be described.

First, the detection signal H1 by the first capacitor combination 610 will be described.
When the contact part 130 is displaced by ΔR in the θ direction, the X direction component of the displacement of the contact part 130 is ΔX (= ΔR cos θ).
Due to the displacement ΔX in the X direction of the contact portion 130, the tip portions 340 of the first Eden spring mechanism 411 and the fifth Eden spring mechanism 415 of the first parallel Eden spring mechanism 410 disposed in the X direction are displaced according to ΔX. To do.
The displacements of the first Eden spring mechanism 411 and the fifth Eden spring mechanism 415 are detected by the first capacitor unit 611 and the fifth capacitor unit 615 of the first capacitor combination 610, respectively.
Here, since ΔX = ΔRcosθ, the detection signals from the first capacitor unit 611 and the fifth capacitor unit 615 are S1 = KΔRcosθ and S5 = −KΔRcosθ, respectively.

  K is a predetermined gain, and this gain K has the following relationship with respect to the length L from the contact portion 130 to the swing fulcrum 811 and the radius r of the virtual circle C (see FIG. 1). Note that a is a predetermined coefficient.

  K = a × r / L

  The detection signal H1 of the first capacitor combination 610 is represented by the difference between S1 and S5.

H1 = S1-S5
= 2KΔR cos θ

The detection signal H2 by the second capacitor combination 620 will be described.
When the contact part 130 is displaced by ΔR in the θ direction, the 45 degree component of the displacement of the contact part 130 is ΔV (= ΔR cos (π / 4−θ)).
Due to the displacement ΔV in the 45-degree direction of the contact portion 130, the tip portions 340 of the second Eden spring mechanism 422 and the sixth Eden spring mechanism 426 of the second parallel Eden spring mechanism 420 arranged in the 45 degree direction correspond to ΔV. To displace. The displacements of the second Eden spring mechanism 422 and the sixth Eden spring mechanism 426 are detected by the second capacitor portion 622 and the sixth capacitor portion 626 of the second capacitor combination 620, respectively.
Here, since ΔV = ΔRcos (π / 4−θ), the detection signals from the second capacitor unit 622 and the sixth capacitor unit 626 are S2 = KΔRcos (π / 4−θ) and S6 = −KΔRcos (π / 4−θ). The detection signal H2 of the second capacitor combination 620 is represented by the difference between S2 and S6.

H2 = S2-S6
= 2KΔRcos (π / 4-θ)

The detection signal H3 by the third capacitor combination 630 will be described.
When the contact part 130 is displaced by ΔR in the θ direction, the Y direction component of the displacement of the contact part 130 is ΔY (= ΔR sin θ). Due to the displacement ΔY in the Y direction of the contact portion 130, the tip portions 340 of the third Eden spring mechanism 433 and the seventh Eden spring mechanism 437 of the third parallel Eden spring mechanism 430 disposed in the Y direction are displaced according to ΔY. . The displacements of the third Eden spring mechanism 433 and the seventh Eden spring mechanism 437 are detected by the third capacitor portion 633 and the seventh capacitor portion 637 of the third capacitor combination 630, respectively. Here, since ΔY = ΔRsinθ, the detection signals from the third capacitor unit 633 and the seventh capacitor unit 637 are S3 = KΔRsinθ and S7 = −KΔRsinθ, respectively. The detection signal H3 of the third capacitor combination 630 is represented by the difference between S3 and S7.

H3 = S3-S7
= 2KΔRsinθ

The detection signal H4 by the fourth capacitor combination 640 will be described.
When the contact portion 130 is displaced by ΔR in the θ direction, the −45 degree direction component of the displacement of the contact portion 130 is ΔW (= ΔRsin (π / 4−θ)).
Due to the displacement ΔW in the −45 degree direction of the contact part 130, the tip portions 340 of the fourth Eden spring mechanism 444 and the eighth Eden spring mechanism 448 of the fourth parallel Eden spring mechanism 440 arranged in the −45 degree direction are ΔW. Displaces according to The displacements of the fourth Eden spring mechanism 444 and the eighth Eden spring mechanism 448 are detected by the fourth capacitor portion 644 and the eighth capacitor portion 648 of the fourth capacitor combination 640, respectively.
Here, since ΔW = ΔRsin (π / 4−θ), the detection signals from the fourth capacitor unit 644 and the eighth capacitor unit 648 are S4 = KΔRsin (π / 4−θ) and S8 = −KΔRsin (π / 4−θ).
The detection signal H4 of the fourth capacitor combination 640 is represented by the difference between S4 and S8.

H4 = S4-S8
= 2KΔRsin (π / 4-θ)

  As described above, the displacement direction θ of the contact portion is obtained by the following two formulas based on the detection signals H1 to H4 detected by the capacitor combinations 610 to 640.

  tan θ = H3 / H1

  tan (π / 4-θ) = H4 / H2

  Further, the displacement amount ΔR can be obtained by the following two formulas.

ΔR ² = (H1 ² + H3 ² ) / 4K ²

ΔR ² = (H2 ² + H4 ² ) / 4K ²

  Next, the operation of braking the fine vibrations of the Eden spring mechanisms 411 to 448 by the braking means 700 will be described.

Since the Eden spring mechanisms 411 to 448 are long plate springs 310 and 320, the tip ends of the Eden spring mechanisms 411 to 448 are moved when the tip end portion 340 of the Eden spring mechanisms 411 to 448 is oscillated and displaced according to the displacement of the contact portion 130. Although there is a possibility that slight vibration may occur in the portion 340, the vibration of the Eden spring mechanisms 411 to 448 is braked by the braking means 700. That is, if the leaf springs 310 and 320 of the eden spring mechanisms 411 to 448 are deformed so as to bend when the tip portions 340 of the eden spring mechanisms 411 to 448 are displaced, the conductive plate 710 is displaced. Then, since the conductive plate 710 is sandwiched between the two magnets 720 and 730, an eddy current is generated in the conductive plate 710 due to the movement of the conductive plate 710. A braking force opposite to the moving direction of the conductive plate 710 acts on the conductive plate 710 by the eddy current and the magnetic flux of the magnets 720 and 730.
Since the fluctuation of the conductive plate 710 is suppressed by this braking force, the fine vibrations of the Eden spring mechanisms 411 to 448 are suppressed.

According to 1st Embodiment provided with such a structure, there can exist the following effects.
(1) The displacement of the contact portion 130 can be increased to a large displacement by the Eden spring mechanisms 411 to 448, and the displacement of the contact portion 130 is detected by detecting the displacement of the tip portion 340 of the expanded Eden spring mechanisms 411 to 448. The resolution can be improved. For example, since the Eden spring mechanism 411 to 448 can make the displacement of the probe 110 several tens of times, the detection resolution can be greatly improved.

(2) Since the displacement of the contact portion 130 is enlarged by the Eden spring mechanisms 411 to 448, even when the contact portion 130 is brought into contact with the surface of the object to be measured and the surface of the object to be measured is detected, the contact portion 130 is slightly displaced. What is necessary is just to make the contact part 130 contact | abut to the to-be-measured object surface with the weak contact pressure of a grade, and to-be-measured object surface is not damaged.

(3) Although the displacement magnifying mechanism 400 includes eight Eden spring mechanisms 411 to 448, the Eden spring mechanisms 411 to 448 have a simple configuration in which two leaf springs 310 and 320 are arranged close to each other, have small components and are extremely small. Since there are few, the displacement expansion mechanism part 400 can be reduced in size extremely. As a result, there is an epoch-making effect that it can be miniaturized while having high resolution as compared with the conventional displacement sensor.

(4) Since the eight Eden spring mechanisms 411 to 448 are arranged at equal intervals on the circumference of the virtual circle C, the eight Eden spring mechanisms 411 to 448 have no anisotropy, and the displacement of the contact portion 130 On the other hand, the eight Eden spring mechanisms 411 to 448 react with the same sensitivity. Therefore, there is no error due to the detection direction in detecting the displacement of the contact portion 130, and the detection accuracy can be improved.

(5) The displacement enlarging mechanism 400 has four sets of parallel Eden spring mechanisms 410 to 440. Since the two Eden spring mechanisms 411 to 448 are arranged as the parallel Eden spring mechanisms 410 to 440 in one plane. The in-plane displacement component can be detected with twice the amount of information. Further, since the measuring element 110 is opposed to the center, the two Eden spring mechanisms constituting the parallel Eden spring mechanisms 410 to 440 show different sensitivities to the displacement of the measuring element 110. Therefore, the displacement and displacement direction of the measuring element 110 in the plane including the two Eden spring mechanisms 410 to 440 of the parallel Eden spring mechanisms 410 to 440 are uniquely obtained from the displacement of each tip 340 of each Eden spring mechanism of the parallel Eden spring mechanisms 410 to 440. Can do. Furthermore, if there are two sets of parallel Eden spring mechanisms 410 to 440, the displacement amount and the direction of displacement of the probe 110 can be obtained sufficiently. By providing four sets of parallel Eden spring mechanisms 410 to 440, which are twice that amount, The displacement amount and displacement direction of the probe 110 can be double checked.

(6) Since the Eden spring mechanisms 411 to 448 are arranged in parallel to the stylus axis direction, the displacement sensor 100 can be configured to be vertically long along the stylus axis.

(7) In detecting the displacement of the tip portion 340 of the Eden spring mechanisms 411 to 448, the displacement detecting means 600 uses the tip portion 340 of the Eden spring mechanisms 411 to 448 as a movable electrode as it is, and the tip portion 340 of each Eden spring mechanism 411 to 448. Since only the two fixed electrodes 510 and 520 are provided on the opposite sides of each other, the displacement detecting means 600 is very small in size with few components. As a result, a very small displacement sensor 100 can be obtained.

(8) Since the vibration of the Eden spring mechanisms 411 to 448 can be suppressed by the braking means 700, the detection error due to the vibrations of the Eden spring mechanisms 411 to 448 can be eliminated and the detection accuracy can be improved.
Since the braking means 700 includes only the conductive plate 710 and the magnets 720 and 730, the configuration is simple, and the displacement sensor 100 can be very downsized while having the braking function of the Eden spring mechanisms 411 to 448. .

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the second embodiment is the same as that of the first embodiment, but is characterized by the configuration of the displacement detection means 600. That is, the second embodiment is characterized in that the displacement of the tip 340 of the Eden spring mechanisms 411 to 448 is photoelectrically detected.
FIG. 9 is a cross-sectional view of the second embodiment cut in the vertical direction.
FIG. 10 is a longitudinal sectional view cut horizontally along the line XX in FIG.

  In FIG. 9, the displacement detection means 600 is provided in the illumination optical system 660 that irradiates light toward the tip portion 340 of the Eden spring mechanisms 411 to 448 and the tip portion 340 of the Eden spring mechanisms 441 to 448. A right-angle prism 670 as an optical element that reflects light and an optical sensor 680 that detects light reflected by the right-angle prism 670 are provided.

  The illumination optical system 660 includes a light emitting unit (light emitting unit) 661 that emits light, a collimator lens 662 that converts the light from the light emitting unit 661 into a parallel light beam, and eight of the parallel light beams from the collimator lens 662. An aperture plate 663 having eight apertures 664 that allows thin fine rays to pass therethrough, and a polygon prism (polyhedral prism) 665 that reflects each fine ray that has passed through the apertures 664 toward the tip 340 of each Eden spring mechanism. The illumination optical system 660 is provided in the sensor body 200 with its optical axis substantially coincident with the center line I.

The light emitting unit 661 emits light from the optical fiber 669 disposed at a position on the center line I on the top plate 212 of the housing unit 210 along the center line I.
Here, a cylindrical inner cylinder portion 215 is attached to the top plate 212 so as to hang down, and the collimator lens 662, the aperture plate 663, and the polygon prism 665 are attached and fixed in the inner cylinder portion 215.
The aperture plate 663 has an aperture 664 that is eight pores. The apertures 664 are formed at equal intervals of 45 degrees corresponding to the positions where the eight eden spring mechanisms 411 to 448 are disposed.

  The polygon prism 665 has eight facets 666 corresponding to the eight Eden spring mechanisms 411 to 448, and each facet 666 passes the fine light beam that has traveled through the aperture 664 of the aperture plate 663 in a perpendicular direction. reflect. A light passage hole 216 for allowing light from the polygon prism 665 to enter the right-angle prism 670 is formed on the side surface on the lower end side of the inner cylindrical portion 215. The light reflected by the facet 666 passes through the light passage hole 216 formed in the side surface of the inner cylinder part 215 and enters the right-angle prism 670.

  The right-angle prism 670 reflects the fine light beam that has passed through the light passage hole 216 from the polygon prism 665 toward the top plate. The right-angle prism 670 is disposed at the tip 340 of the Eden spring mechanisms 411 to 448. When the tip 340 of the Eden spring mechanisms 411 to 448 is displaced, the posture of the right-angle prism 670 changes. The light reflection direction due to changes.

  The optical sensor 680 is a two-dimensional optical sensor 680 that detects the incident position of light, and eight optical sensors 680 are provided on the top plate 212 corresponding to the Eden spring mechanisms 411 to 448. The optical sensor 680 detects the position of the light reflected from the right-angle prism 670.

  In order to increase the distance h between the optical sensor 680 and the right-angle prism 670, the lengths of the Eden spring mechanisms 411 to 448 are shorter than those in the first embodiment. In FIG. 9, the distance from the right-angle prism 670 to the optical sensor 680 is slightly longer than the length of the Eden spring mechanisms 411 to 448.

  In such a second embodiment, an operation for detecting the displacement of the tip 340 of the Eden spring mechanisms 411 to 448 will be described.

  The light emitted from the light emitting unit 661 becomes a parallel light beam by the collimator lens 662 and enters the aperture plate 663. Then, eight fine light beams that have passed through the respective apertures 664 of the aperture plate 663 enter the polygon prism 665. The light incident on the polygon prism 665 is reflected by the facets 666 in a right angle direction, passes through the light passage hole 216 of the inner cylinder portion 215, and enters the right angle prism 670. The light incident on the right-angle prism 670 is reflected toward the two-dimensional photosensor 680 and received by the two-dimensional photosensor 680.

  Here, when the tip portion 340 of the Eden spring mechanism 411 to 448 is oscillated and displaced from the reference position by an angle φ, the light reflection direction by the right-angle prism 670 changes by 2φ, which is twice the angle change φ of the tip portion 340. To do. If the distance from the right-angle prism 670 to the light sensor 680 is h, the light reflection direction changes by 2φ, so that the light incident position on the light sensor 680 changes by 2φh. For example, the displacement of the tip 340 of the Eden spring mechanisms 411 to 448 is Δx = 0.01 μm, the distance a between the first plate spring 310 and the second plate spring 320 of the Eden spring mechanisms 411 to 448 is 0.2 mm, and a right angle prism. Assuming that the distance h between 670 and the optical sensor 680 is 50 mm, the amount of change in the light incident position on the optical sensor 680 is obtained as follows.

φ≈X / a = 0.5 × 10 ⁻⁴
2φh = 5μm

  That is, the displacement (0.01 μm) at the tip portion 340 of the Eden spring mechanism 411 to 448 is magnified 500 times on the optical sensor 680.

According to such 2nd Embodiment, in addition to said effect (1)-(6) (8), there can exist the following effect.
(9) Since the displacement detection means 600 is configured to photoelectrically detect the displacement of the tip portion 340 of the Eden spring mechanism 411 to 448, the displacement of the tip portion 340 of the Eden spring mechanism 411 to 448 is enlarged and detected by an “optical lever”. can do.
That is, when the tip portion 340 of the Eden spring mechanism 411 to 448 is oscillated and displaced by an angle φ, the light reflection direction by the right-angle prism 670 provided in the tip portion 340 changes by 2φ which is twice the displacement angle φ of the tip portion 340. Therefore, the incident position of light on the optical sensor 680 shows a large change of 2φh depending on the distance h between the right-angle prism 670 and the optical sensor 680. Therefore, in addition to the displacement of the contact portion 130 being expanded to a large displacement of the distal end portion 340 by the Eden spring mechanisms 411 to 448, the displacement of the distal end portion 340 is further expanded by the “optical lever”, so that the detection resolution is epoch-making. Can be improved.

(10) Since the illumination optical system 660 has one light emitting unit 661 that is a light source, the number of components can be reduced as compared with the case where light sources are provided by the number of Eden spring mechanisms 411 to 448, for example.

(11) In the optical sensor 680, it is necessary to detect a change in the incident position of light. However, light incident on the optical sensor 680 must be incident in a spot shape, and the incident point must be detected by the optical sensor 680. In this respect, in the second embodiment, the light is narrowed by the aperture 664 having a small diameter to be incident on the optical sensor 680 as a fine light beam. Therefore, the optical sensor 680 can detect a change in the incident position of the light.

(12) For example, a light emitting unit 661, a collimator lens 662, and a polygon prism 665 are disposed along the axis of the stylus 120 so that the optical axis of the illumination optical system 660 coincides with the axial direction of the stylus 120. Since the optical sensor 680 is disposed at a position separated from the distal end portion 340 of the eden spring mechanism 411 to 448 along the axial direction of the stylus 120, the displacement sensor 100 can be configured to be vertically long along the axial direction of the stylus 120.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the third embodiment is the same as that of the first embodiment, but is characterized in that the swing fulcrum 811 of the contact portion 130 is structurally fixed.
In FIG. 11, the displacement sensor 100 includes a swing fulcrum fixing means 800 that fixes a swing fulcrum 811 of the contact portion 130, and the swing fulcrum fixing means 800 is a fixed ball 810 that becomes the swing fulcrum 811 of the contact portion 130. And fixed ball positioning means 820 for fixing the position of the fixed ball 810.

The fixed sphere 810 is a sphere whose position is substantially fixed at the center of the virtual circle C.
The fixed ball positioning means 820 includes an inner cylinder portion 215 provided in a state of hanging from the top plate 212, a cylindrical block 822 in which a fixed ball 810 is embedded in the lower end surface, and two circular thin plates that support the cylindrical block 822. And springs 823 and 824.

The inner cylinder part 215 has a length from the top plate 212 to a position close to the movable part 460.
The cylindrical block 822 is disposed inside the inner cylinder portion 215, and a fixed ball 810 is embedded and fixed on the lower end surface.
Two circular thin leaf springs 823 and 824 are provided.
The first circular thin plate spring 823 is provided on the lower end surface of the inner cylinder portion 215 and is connected to the lower end surface of the cylindrical block 822.
The second circular thin plate spring 824 is disposed at a height substantially the same as the upper surface of the inner cylinder portion 215 inside the inner cylinder portion 215, and is connected to the upper end surface of the cylindrical block 822. The two circular thin plate springs 823 and 824 restrict the displacement of the cylindrical block 822 in the direction intersecting the center line I, and the direction along the center line I is allowed by the deflection of the circular thin plate springs 823 and 824. The

  A conical small hole 461 is formed at the center of the virtual circle C on the upper surface of the movable portion 460, and the fixed ball 810 is fitted so as to be smoothly slidable.

  In such a configuration, when the contact portion 130 is displaced in the XY plane, the stylus 120 swings with the fixed ball 810 as the swing fulcrum 811. At this time, the movable portion 460 also swings with the fixed ball 810 as the fulcrum 811, and the free end 311 of the Eden spring mechanisms 411 to 448 is displaced as the end portion of the movable portion 460 moves up and down. The displacement of the free end 311 is expanded to the displacement of the tip portion 340 of the Eden spring mechanism 411 to 448, and the displacement of the tip portion 340 is detected by the displacement detection means 600.

  Further, when the contact part 130 is displaced in the Z direction, the movable part 460 is displaced in the Z direction together with the measuring element 110. Due to the displacement of the movable portion 460, the free end 311 of the Eden spring mechanism 411 to 448 is displaced and expanded to the displacement of the tip end portion 340 of the Eden spring mechanism 411 to 448. Is detected. At this time, since the cylindrical block 822 is supported by the circular thin plate springs 823 and 824, the deflection of the circular thin plate springs 823 and 824 causes the fixed ball 810 to be displaced in the Z direction together with the cylindrical block 822.

According to such 3rd Embodiment, in addition to said effect (1)-(8), there exists the following effect.
(13) Since the rocking fulcrum fixing means 800 is provided, the rocking fulcrum of the contact portion 130 can be structurally fixed. Since the swing fulcrum of the contact portion 130 is structurally fixed in this manner, the displacement of the contact portion 130 can be easily calculated from the displacement of the tip portion 340 of the Eden spring mechanism.

(14) When the rocking fulcrum is not fixed structurally, the rocking fulcrum of the contact portion 130 varies depending on the strength of the Eden spring mechanism 411 to 448. Therefore, the tip 340 of the Eden spring mechanism 411 to 448 Although an equation for calculating the displacement amount of the contact portion 130 from the displacement must be created for each product according to the position of the swing fulcrum, in the third embodiment, the swing fulcrum 811 is fixed. The same calculation formulas and parameters can be used for all products, which is convenient. Therefore, it is not necessary to obtain the position of the oscillating fulcrum for each product by a test, so that labor of manufacturing can be saved and manufacturing efficiency can be improved.

(15) Since the fixed sphere 810 as the swing fulcrum 811 is provided, the contact portion 130 can swing with the fixed sphere 810 as the fulcrum 811. At this time, since the fulcrum 811 is a sphere, the swinging direction of the contact part 130 is not limited to, for example, one plane, and the contact part 130 can freely swing and displace in all directions. For example, even when the contact portion 130 is brought into contact with the surface of the object to be measured and the surface of the object to be measured is detected, the contact portion 130 can approach the surface of the object to be measured from all directions.

(16) Since the small hole 461 is provided in the movable portion 460, and the fixed ball 810 is fitted in the small hole 461, the movable portion 460 does not shift with respect to the fixed ball 810, and as a result, the contact portion 130 is surely secured. The fixed ball 810 swings as a swing fulcrum 811.

(17) Since the movable part 460 contacts the fixed sphere 810 and the fulcrum of the swing is fixed, the movable part 460 swings with the fixed sphere 810 as a fulcrum when the contact part 130 is displaced in the X direction (or Y direction). The center of the movable part 460 is not displaced in the Z direction. On the other hand, when the contact part 130 is displaced in the Z direction, the movable part 460 is displaced in the Z direction. Thus, as long as the contact part 130 is displaced in the X direction (or Y direction), the center of the movable part 460 is not displaced in the Z direction, and the movable part 460 is only displaced when the probe 110 is displaced in the Z direction. (Center) is displaced in the Z direction. That is, the displacement of the contact portion 130 in the Z direction and the displacement in the X direction are clearly separated.

(Modification 1)
Modification 1 of the present invention will be described with reference to FIG.
The basic configuration of Modification 1 is the same as that of the third embodiment, but is characterized by the configuration of the displacement detection means 600, that is, the displacement of the tip 340 of the Eden spring mechanism as described in the second embodiment. It is characterized in that it is provided with a displacement detection means 600 for photoelectrically detecting.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG.
The basic configuration of the fourth embodiment is the same as that of the second embodiment, but the Eden spring mechanisms 411 to 448 are arranged with their longitudinal directions oriented in a direction that forms an angle of 45 degrees with respect to the center line I. It is characterized in that it is installed.

In FIG. 13, a fixed cylinder 217 is attached and fixed to the lower end side of the housing portion 210.
The fixed cylinder 217 has a through hole 218 that passes through the center, and the upper opening of the through hole 218 is a conical wide-mouthed portion 219. A movable portion 460 is disposed in the wide opening 219 of the fixed cylinder 217.
The fixed ends 321 of the Eden spring mechanisms 411 to 448 are attached and fixed to the side surface of the fixed cylinder 217, and the free end 311 is connected to the movable portion 460.
The measuring element 110 is inserted into the through hole 218 of the fixed cylinder 217 with the contact portion 130 positioned outside, and the proximal end of the stylus 120 is attached to the movable portion 460.

The configuration of the displacement detection means 600 is basically the same as the configuration described in the second embodiment, except for the following points. That is, the illumination optical system 660 includes a condenser lens 667 instead of the collimator lens 662 and a circular shielding plate 668 instead of the aperture plate 663. The circular shielding plate 668 is disposed between the light emitting part 661 and the condenser lens 667 so as to shield the central part of the light beam.
Further, a flat mirror 671 is provided at the tip 340 of the Eden spring mechanisms 411 to 448 in place of the right-angle prism 670.

  Light from the light emitting unit 661 is applied to the condensing lens 667, and an image is formed at the focal position by the condensing lens 667. Here, the focal position of the condenser lens 667 is the surface of the optical sensor 680. That is, the light from the light emitting unit 661 passes through the condenser lens 667 and enters the polygon prism 665. The light incident on the polygon prism 665 is reflected by the facets 666 of the polygon prism 665 and is incident on the plane mirror 671 provided at the tip 340 of each Eden spring mechanism 411 to 448. Then, the light reflected by the plane mirror 671 enters the optical sensor 680 and forms an image on the surface of each optical sensor 680.

In the fourth embodiment, the displacement of the tip 340 of the eden spring mechanisms 411 to 448 provided at 45 degrees will be described.
When the contact portion 130 is displaced by ΔX in the X direction, the swing angle φx of the tip portion 340 of the Eden spring mechanism 411 to 448 is expressed by the following equation.
Here, a is the distance between the first leaf spring 310 and the second leaf spring 320 of the Eden spring mechanism 411 to 448, l is the distance from the movable portion 460 to the swing fulcrum 811, and r is the virtual circle C. Radius.

  Here, assuming that the Eden spring mechanism is disposed parallel to the center line as in the first embodiment, when the contact portion 130 is displaced by ΔX in the X direction, the swing angle φx of the tip portion 340 of the Eden spring mechanism 411 to 448 is changed. Is represented by the following equation. Here, L is the distance from the contact portion 130 to the swing fulcrum 811.

  Here, when the ratio of both sides is taken between (Equation 1) and (Equation 2), it is as follows.

That is, by disposing the eden spring mechanisms 411 to 448 at 45 degrees, compared to the case where the eden spring mechanisms 411 to 448 are disposed in parallel to the center line I as in the first embodiment, the contact portion 130 is not displaced in the X direction. The swing angle φx of the tip 340 changes by the value on the right side of (Equation 3).
Then, if the right side of (Equation 3) is made larger than 1 by making the distance l from the movable part 460 to the rocking fulcrum 811 larger than the radius r of the virtual circle C, the rocking of the tip part 340 of the Eden spring mechanism The angle φx increases by the value on the right side of (Expression 3).

According to 4th Embodiment provided with such a structure, in addition to said effect (1)-(6) (8)-(12), there exists the following effect.
(18) Since the Eden spring mechanisms 411 to 448 are disposed at 45 degrees with respect to the stylus axial direction, the X direction of the contact portion 130 (as compared to the case where the Eden spring mechanisms 411 to 448 are disposed parallel to the stylus axial direction ( (Y direction) Sensitivity to displacement is improved. Then, by arranging the Eden spring mechanisms 411 to 448 at 45 degrees, the sensitivity to the X direction (Y direction) displacement of the contact portion 130 is reduced while the radius r of the virtual circle C on which the Eden spring mechanisms 411 to 448 are arranged is reduced. Since it can improve, it can be set as the small displacement sensor 100 with high sensitivity to the X direction (Y direction) displacement.

(19) In the optical sensor 680, it is necessary to detect a change in the incident position of the light. However, the light incident on the optical sensor 680 must be incident in a spot shape, and the incident point must be detected by the optical sensor 680. In this respect, since the light from the light emitting unit 661 forms an image on the sensor surface of the optical sensor 680 by the condenser lens 667, a change in the incident position of the light can be detected by the optical sensor 680. Further, since the light from the light emitting unit 661 is imaged by the condenser lens 667 so that the light is incident on the optical sensor 680 in a spot shape, for example, compared with a case where the light beam is narrowed by the aperture 664 to be a fine light beam. Light loss can be reduced.

Here, for example, the displacement amount of the tip portion 340 of the Eden spring mechanism when the contact portion 130 is displaced in the z direction and the displacement amount of the tip portion 340 of the Eden spring mechanism when the contact portion 130 is displaced in the x direction are “1”. : 1 ”, the following may be performed.
The swing angle φz of the tip portion 340 of the Eden spring mechanism when the contact portion 130 is displaced by ΔZ in the Z direction is expressed by the following equation.

  In order to compare (Equation 4) with (Equation 1) and set the ratio of both sides to 1, the following equation should be satisfied.

  cos (π / 4) = {lsin (π / 4) + rcos (π / 4)} / L

  That is, since L = l tan (π / 4) + r, L = r + 1 may be set.

  Further, the displacement amount of the tip portion 340 of the Eden spring mechanism when the contact portion 130 is displaced in the z direction and the displacement amount of the tip portion 340 of the Eden spring mechanism when the contact portion 130 is displaced in the x direction are “k: 1”. (Where k> 1), tanφz: tanφx = k: 1, so L = k (r + l) may be set.

The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the above-described embodiment, the case where the displacement enlarging mechanism unit includes eight Eden spring mechanisms has been described as an example, but three Eden spring mechanisms 300 may be provided. For example, as shown in FIG. 14, three Eden spring mechanisms may be arranged on the circumference of the virtual circle C at equal intervals (120 degree intervals). Alternatively, when there are four Eden spring mechanisms, they may be arranged at intervals of 90 degrees.

  In the Eden spring mechanism, the first plate spring 310 and the second plate spring 320 are bent in the middle of a single plate spring, and the bent portion is bent in two stages to form two right angle bends. The case of using the spring 310 and the second plate spring 320 has been described as an example. For example, a thin plate-like shape is used between the first plate spring 310 and the second plate spring 320 using two plate springs. You may connect via a connection member.

  The Eden spring mechanism may be parallel to the center line I, an angle of 45 degrees with respect to the center line, or an angle within 45 degrees with respect to the center line I.

  In the first embodiment, the fixed electrode of the displacement detecting means may be formed of a metal plate, or may be formed by evaporating a metal thin film on the housing part and the inner cylinder part, for example.

  The free end 311 is inside the virtual circle C, the fixed end 321 is outside the virtual circle C, the outside is a fixed member, and the inside is a movable part 460, but the reverse is also possible. In other words, the fixed portion 450 may be on the inside, the movable portion 460 may be ring-shaped and arranged on the outside, the fixed end 321 may be fixed to the fixed portion 450, and the free end 311 may be connected to the outer movable portion 460. When the radius of the movable portion 460 is larger, the swinging displacement of the end portion of the movable portion 460 with respect to the displacement of the contact portion 130 is also larger, so that the free end 311 is greatly displaced, and as a result, the tip end portion 340 of the Eden spring mechanism is increased. Displacement also increases and detection sensitivity improves.

  In the second and fourth embodiments, a right-angle prism and a reflecting mirror have been described as examples of the optical element that reflects toward the optical sensor from the polygon prism. However, as the optical element, light from the illumination optical system is used. A prism that refracts as well as reflects may be used. Moreover, the light emission part may be provided with two or more instead of one, for example, the number of Eden spring mechanisms may be provided.

  In the above embodiment, the shape measuring machine for measuring the shape of the object to be measured has been described as an example. However, the displacement sensor of the present invention is also applicable to a surface property measuring apparatus for measuring the surface roughness, waviness, etc. of the object to be measured. Applicable.

  The present invention can be used for a probe as a displacement sensor.

It is the cross-sectional view which cut | disconnected 1st Embodiment in the up-down direction. It is the longitudinal cross-sectional view cut | disconnected horizontally in the II-II line | wire in FIG. It is a perspective view which shows the structure of a displacement expansion mechanism part. The figure which shows the change of the 1st parallel Eden spring mechanism 410 when a contact part is displaced upwards (+ Z direction). The figure which shows the change of the 1st parallel Eden spring mechanism 410 when a contact part is displaced below (-Z direction). The figure which shows the change of the 1st parallel Eden spring mechanism 410 when a contact part is displaced to a horizontal direction (+ X direction). The enlarged view of the state which the front-end | tip part of the Eden spring mechanism displaced. The figure which shows a cantilever compared with an Eden spring mechanism. The cross-sectional view which cut | disconnected 2nd Embodiment in the up-down direction. The longitudinal cross-sectional view cut | disconnected horizontally in the XX line in FIG. The figure which shows the structure of 3rd Embodiment. The figure which shows the structure of the modification 1. FIG. The figure which shows the structure of 4th Embodiment. The figure which shows the example in the case of providing three Eden spring mechanisms. The figure which shows the structure of the shape measuring apparatus using a probe in description of background art. The figure which shows a probe in description of background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Shape measuring apparatus, 11 ... Probe, 12 ... Drive mechanism, 13 ... Stylus, 14 ... Contact part, 15 ... Main part, 100 ... Displacement sensor, 110 ... Measuring element, 120 ... Stylus, 130 ... Contact part, 200 ... Sensor body part 210 ... Housing part 211 ... Storage space 212 ... Top plate 213 ... Signal extraction hole 214 ... Lower end opening edge 215 ... Inner cylinder part 216 ... Light passage hole 217 ... Fixed cylinder, 218 ... through hole, 219 ... wide opening, 300 ... eden spring mechanism, 310 ... first leaf spring, 311 ... free end,
320 ... second leaf spring, 321 ... fixed end, 340 ... tip, 400 ... displacement enlarging mechanism, 410 ... first parallel Eden spring mechanism, 411 ... first Eden spring mechanism, 415 ... 5th Eden spring mechanism, 420 ... second Parallel Eden Spring Mechanism, 422 ... Second Eden Spring Mechanism, 426 ... Sixth Eden Spring Mechanism, 430 ... Third Parallel Eden Spring Mechanism, 433 ... Third Eden Spring Mechanism, 437 ... Seventh Eden Spring Mechanism, 440 ... Fourth Parallel Eden Spring Mechanism, 444 ... 4th Eden spring mechanism, 448 ... 8th Eden spring mechanism, 450 ... Fixed portion, 460 ... Movable portion, 461 ... Small hole, 490 ... Cantilever, 491 ... Leaf spring, 492 ... Tip, 510 ... Fixed electrode, 511 ... Ground wire 520: Fixed electrode set, 521: Outer fixed electrode, 522: Inner fixed electrode, 523: Signal leader, 600: Displacement detecting means, 6 DESCRIPTION OF SYMBOLS 1 ... 1st capacitor | condenser part, 615 ... 5th capacitor | condenser part, 622 ... 2nd capacitor | condenser part, 626 ... 6th capacitor | condenser part, 633 ... 3rd capacitor | condenser part, 637 ... 7th capacitor | condenser part, 644 ... 4th capacitor | condenser part, 648 ... 8th condenser section, 650 ... signal processing section, 660 ... illumination optical system, 661 ... light emitting section, 662 ... collimator lens, 663 ... aperture plate, 664 ... aperture, 665 ... polygon prism, 666 ... facet, 667 ... Condensing lens, 668 ... Circular shielding plate, 669 ... Optical fiber, 670 ... Right angle prism, 671 ... Planar mirror, 680 ... Optical sensor, 700 ... Braking means, 710 ... Conductive plate, 720 ... First magnet, 730 ... Second Magnet, 740 ... Connecting member, 800 ... Swing fulcrum fixing means, 810 ... Fixed ball, 811 ... Swing fulcrum, 820 ... Fixed ball -Decided Me means, 822 ... cylindrical block, 823 ... first circular thin plate spring, 824 ... second circular flat spring.

Claims (19)

A measuring element;
A sensor main body for supporting the measuring element in a displaceable manner and detecting the displacement of the measuring element,
The sensor body is
The longitudinal ends of one longitudinal elastic member and the other longitudinal elastic member, which are arranged in parallel and close to each other, are connected to each other while maintaining a predetermined distance, and the base end of the one longitudinal elastic member is a free end. The base end of the other longitudinal elastic member is a fixed end, and the displacement of the free end within a plane including the free end and the fixed end occurs when a displacement including a longitudinal displacement component occurs at the free end. A displacement magnifying mechanism portion having an Eden spring mechanism in which the tip portion swings and displaces more than a displacement amount;
Displacement detecting means for detecting the amount of displacement of the probe by detecting the amount of displacement of the tip portion of the Eden spring mechanism,
The displacement magnifying mechanism includes three or more eden spring mechanisms and supports the measuring element at all free ends of the three or more eden spring mechanisms.
The displacement detecting means detects the displacements of the tip portions of all the Eden spring mechanisms when the probe is displaced, and based on the displacement amounts of the tip portions of the Eden spring mechanisms, the displacement amount and displacement of the probe A displacement sensor characterized by detecting a direction. The displacement sensor according to claim 1,
The three or more Eden spring mechanisms are arranged at equal intervals along the circumference of the virtual circle,
The displacement sensor is characterized in that the measuring element is supported on an axis passing through the center of the virtual circle. The displacement sensor according to claim 2, wherein
The displacement enlarging mechanism unit includes a parallel Eden spring mechanism configured by a set of Eden spring mechanisms disposed at positions facing each other across the center of the virtual circle,
Two or more pairs of the parallel Eden spring mechanisms exist in different directions. The displacement sensor according to claim 3,
The displacement magnifying mechanism section includes four sets of the parallel Eden spring mechanism,
A displacement sensor characterized in that a line connecting two Eden spring mechanisms constituting the parallel Eden spring mechanism intersects at 45 degrees. The displacement sensor according to any one of claims 3 and 4,
The sensor body includes a housing that houses the displacement magnifying mechanism.
The displacement magnifying mechanism is
A ring-shaped fixing portion that is a ring surrounding the virtual circle and fixed to the housing;
A movable part provided inside the virtual circle so as to be displaceable,
The three or more eden spring mechanisms are arranged along the circumference of the virtual circle with the free end facing the center of the virtual circle and the fixed end facing the outside of the virtual circle, and The free end is connected to the movable part and the fixed end is connected to the fixed part;
The displacement sensor is fixed at a position corresponding to the center of the virtual circle in the movable part. The displacement sensor according to any one of claims 1 to 5,
The probe includes a stylus having a contact portion at a tip,
The displacement sensor is characterized in that the Eden spring mechanism is disposed in a state where its longitudinal direction is oriented within 45 degrees with respect to the axial direction of the stylus in a reference state. The displacement sensor according to claim 6.
The displacement sensor, wherein the Eden spring mechanism is disposed in parallel with the axial direction of the stylus in a reference state. The displacement sensor according to claim 6.
The displacement sensor is characterized in that the Eden spring mechanism is disposed in a state in which a longitudinal direction thereof is directed to a direction that forms an angle of 45 degrees with respect to an axis of the stylus in a reference state. The displacement sensor according to any one of claims 1 to 8,
The displacement detecting means is provided at a distal end portion of the Eden spring mechanism, and a movable electrode that is displaced together with the distal end portion;
A displacement sensor, comprising: a fixed electrode provided to face the movable electrode. The displacement sensor according to any one of claims 1 to 8,
The displacement detection means includes
An illumination optical system for irradiating light to the tip of the Eden spring mechanism;
An optical element that is provided at a tip portion of each of the Eden spring mechanisms and reflects or refracts light from the illumination optical system;
A displacement sensor, comprising: an optical sensor that is arranged at a predetermined distance from the optical element and detects a position where light from the optical element is incident two-dimensionally. The displacement sensor according to claim 10.
The illumination optical system includes one light emitting means for emitting light,
A collimator lens for converting the light beam from the light emitting means into a parallel beam;
An aperture plate that is disposed in the next stage of the collimator lens and has a small-diameter aperture that allows a thin light beam to pass therethrough, corresponding to the number of Eden spring mechanisms;
A displacement sensor comprising: a multi-faceted prism having a facet that reflects each of the fine light beams that have passed through the aperture toward the optical element. The displacement sensor according to claim 10.
The illumination optical system includes one light emitting means for emitting light,
A condenser lens for condensing the light from the light emitting means to form an image;
A multifaceted prism having a facet that reflects the light from the condenser lens toward the tip of each Eden spring mechanism, and
The said condensing lens images light on the sensor surface of the said optical sensor. The displacement sensor characterized by the above-mentioned. The displacement sensor according to any one of claims 10 to 12,
The illumination optical system is disposed so that its optical axis substantially coincides with the axis of the probe,
The displacement sensor according to claim 1, wherein the optical sensor is disposed at a position spaced apart from a tip portion of the Eden spring mechanism by a predetermined distance along an axial direction of the measuring element. The displacement sensor according to any one of claims 1 to 13,
The probe includes a stylus having a contact portion at a tip,
The displacement sensor includes a swing fulcrum fixing unit that fixes a swing fulcrum of the contact portion. The displacement sensor according to claim 14, wherein
The swing fulcrum fixing means includes a fixed sphere substantially fixed at a predetermined position on the axis of the stylus,
The displacement sensor swings with the fixed ball as a swing fulcrum. The displacement sensor according to claim 15,
The three or more Eden spring mechanisms are arranged at equal intervals along the circumference of the virtual circle,
The displacement enlarging mechanism includes a movable part that is displaceably provided inside the virtual circle, and the free end of the Eden spring mechanism is coupled to the movable part,
The fixed sphere is substantially fixed in a state where displacement in a direction intersecting the axis of the probe at the center of the virtual circle is restricted and minute displacement in a direction along the axis of the probe is allowed. And
The measuring element is fixed at a position corresponding to the center of the virtual circle in the movable part,
The movable sensor is in contact with the fixed sphere at a position corresponding to the center of the virtual circle. The displacement sensor according to any one of claims 1 to 16,
A displacement sensor comprising braking means for braking the vibration of the Eden spring mechanism. The displacement sensor according to claim 17, wherein
The braking means includes a conductive plate protruding from the one or the other longitudinal elastic member in a direction intersecting the longitudinal direction of the Eden spring mechanism,
A displacement sensor comprising: a magnet disposed in proximity to the conductive plate. The displacement sensor according to any one of claims 1 to 18,
A drive mechanism for moving the displacement sensor relative to the object to be measured to bring the displacement sensor into contact with the surface of the object to be measured;
A drive sensor for detecting a relative displacement between the displacement sensor by the drive mechanism and the object to be measured;
A surface property measuring apparatus comprising: analysis means for analyzing a shape of the object to be measured based on detection values obtained by the displacement sensor and the driving sensor.

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