Measuring device

Abstract

To provide a measuring device equipped with a compact and lightweight movable body.SOLUTION: A measuring device 1 comprises: a movable unit 11 having a mirror 113; a movable unit 12 having a light emission point 121, light incidence points 122a and 122b, and an optical system; a drive mechanism 13 for adjusting a position of the movable unit 12; a control unit 14 for controlling the drive mechanism 13; and at least one optical fiber 16. Light emitted from the light emission point 121 is irradiated on the mirror 113 via the optical system, and reflected light reflected from the mirror 113 enters the light incidence points 122a and 122b. The control unit 14 controls the drive mechanism 13 on the basis of intensity of reflected light having entered the light incidence points 122a and 122b so as to adjust the position of the movable unit 12. The light emission point 121 or the light incidence point 122a or 122b is an end part 161 of the at least one optical fiber 16.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a measuring device.

Background Art

[0002] Contact three-dimensional shape measuring instruments are used to measure the shape of lenses and the like with high precision. Patent Document 1 discloses the configuration of an optical probe used in a contact three-dimensional shape measuring instrument.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a measuring device including a small and lightweight movable body.

Means for Solving the Problems

[0005] A measuring device according to an aspect of the present disclosure includes a first movable body having a reflector, a second movable body having a light emission point, a light incident point, and an optical system, a drive mechanism for adjusting the position of the second movable body, a control unit for controlling the drive mechanism, and at least one optical fiber. The light emitted from the light emission point is irradiated onto the reflector through the optical system, the reflected light reflected from the reflector enters the light incident point, and the control unit adjusts the position of the second movable body by controlling the drive mechanism based on the intensity of the reflected light incident on the light incident point. The light emission point or the light incident point is an end of the at least one optical fiber.

Effects of the Invention

[0006] According to the present disclosure, it is possible to provide a measuring device including a small and lightweight movable body.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0008] (Summary of the Present Disclosure) The present inventor has found that the following problems occur with the optical probe used in the three-dimensional shape measuring instrument disclosed in Patent Document 1. Hereinafter, the problems of the conventional optical probe will be described with reference to the configuration of the optical probe disclosed in Patent Document 1.

[0009] FIG. 6 is a diagram showing a schematic configuration of a conventional three-dimensional shape measuring instrument. As shown in FIG. 6, the three-dimensional shape measuring instrument 1x includes an optical probe 10x. The optical probe 10x is composed of two elements, a movable part 11x and a movable part 12x.

[0010] The movable part 11x moves up and down along the shape of the object to be measured (not shown). The three-dimensional shape measuring instrument 1x irradiates the movable part 11x with light Lx (shown by a broken line in FIG. 6) from the outside of the optical probe 10x, and determines the position of the movable part 11x based on the reflected light. Thereby, the three-dimensional shape measuring instrument 1x obtains the shape information of the object to be measured.

[0011] The movable part 12x has a function of restricting the movement of the movable part 11x in the vertical direction. Also, the movable part 11x and the movable part 12x are connected by a spring 15x. In order to keep the contact strength between the movable part 12x and the object to be measured within a certain range, it is necessary to make the relative position between the movable part 11x and the movable part 12x fall within a certain range.

[0012] Also, in the configuration of Patent Document 1, an objective lens 125x is placed on the movable part 12x. The objective lens 125x condenses the light incident from the outside of the optical probe 10x onto a mirror 113x on the movable part 11x. The objective lens 125x emits the reflected light by the mirror 113x to a laser length measuring device (not shown) outside the optical probe 10x. In order for the reflected light to return to the laser length measuring device, the mirror 113x of the movable part 11x needs to be located near the focal position of the objective lens 125x of the movable part 12x. Also in this sense, in the optical probe 10x, it is necessary to make the relative position between the movable part 11x and the movable part 12x fall within a certain range.

[0013] The movable part 12x includes a semiconductor laser 21x, and photodetectors 31ax and 31bx as means for measuring the relative position between the movable part 11x and the movable part 12x. The reason why the movable part 12x includes two photodetectors 31ax and 31bx is that the dependencies of the signal intensities of the relative positions between the movable part 11x and the movable part 12x are different. With this configuration, when it deviates from the desired relative position, it is possible to calculate in which direction and by how much the movable part 12x should be moved in order to make it the desired relative position.

[0014] As shown in FIG. 6, the contact type three-dimensional shape measuring device includes a driving means 13x and a relative position measuring means 14x.

[0015] The relative position measuring means 14x calculates the relative position between the movable part 11x and the movable part 12x based on the outputs of the photodetectors 31ax and 31bx respectively. The driving means 13x adjusts the relative position between the movable part 11x and the movable part 12x by changing the position of the movable part 12x so that the relative position becomes constant.

[0016] The three-dimensional shape measuring device changes the horizontal relative position between the optical probe 10x and the object to be measured in order to measure the three-dimensional shape of the object to be measured. In this case, the position of the movable part 11x changes in the vertical direction according to the shape of the object to be measured. Each time the horizontal relative position is changed, it is necessary to measure the relative position and change the position of the movable part 12x in order to keep the relative position between the movable part 11x and the movable part 12x constant.

[0017] However, if the position change speed of the movable part 12x is slow, it will limit the shape measurement. Also, if the position change cannot catch up, the relative position between the movable part 11x and the movable part 12x will deviate from the appropriate range. In this case, problems such as the movable part 11x being overly pressed against the object to be measured or the movable part 11x moving away from the object to be measured and being unable to measure properly will occur.

[0018] The weight of the movable part 12x affects the position change speed of the movable part 12x. In order to increase the position change speed, it is required that the movable part 12x be as lightweight as possible. Also, in order to suppress physical interference between the object to be measured and the movable part 12x, it is required that the movable part 12x be as small as possible.

[0019] Therefore, an object of the present disclosure is to provide a measuring device including a small and lightweight movable body.

[0020] The measuring device according to the first aspect of the present disclosure includes a first movable body having a reflector, a second movable body having a light emission point, a light incidence point, and an optical system, a drive mechanism for adjusting the position of the second movable body, a control unit for controlling the drive mechanism, and at least one optical fiber. The light emitted from the light emission point is irradiated onto the reflector through the optical system, the reflected light reflected from the reflector is incident on the light incidence point, and the control unit adjusts the position of the second movable body by controlling the drive mechanism based on the intensity of the reflected light incident on the light incidence point, and the light emission point or the light incidence point is an end of the at least one optical fiber.

[0021] As a result, since the light emission point or the light incident point is at the end of at least one optical fiber, miniaturization and weight reduction of the second movable body can be achieved. This is because generally the size of the end of the optical fiber is smaller than that of the semiconductor laser or the photodetector, and thus it can contribute to the miniaturization and weight reduction of the second movable body. Also, when elements such as a semiconductor laser or a photodetector are provided, a power supply line for supplying power to operate the elements and a signal line for extracting the signal output from the elements are required. On the other hand, by using an optical fiber, it becomes unnecessary to provide a power supply line and a signal line, and the number of cables connected to the second movable body can be reduced. Also in this regard, miniaturization and weight reduction of the second movable body can be realized.

[0022] The measuring device according to the second aspect of the present disclosure is the measuring device according to the first aspect, and when measuring an object, the first movable body contacts the object.

[0023] When a contact-type measuring device measures a measurement object, the distance between the second movable body and the measurement object also becomes short. Therefore, by miniaturizing the second movable body, it becomes easier to avoid contact between the second movable body and the measurement object.

[0024] The measuring device according to the third aspect of the present disclosure is the measuring device according to the first aspect or the second aspect, and includes an elastic body that connects the first movable body and the second movable body.

[0025] As a result, it becomes easier to keep the relative positions of the first movable body and the second movable body within a certain range. Also, in the case of a contact-type measuring device, the force for pressing the first movable body against the measurement object can be applied by the elastic body. It is possible to suppress the first movable body from separating from the measurement object, and the measurement accuracy can be improved.

[0026] The measuring device according to the fourth aspect of the present disclosure is a measuring device according to any one of the first to third aspects, wherein the at least one optical fiber includes a first optical fiber, the light emission point is a first end of the first optical fiber, and the second movable body includes a beam splitter that separates the reflected light into a first reflected light and a second reflected light, a first light shielding member having a first pinhole into which the first reflected light is incident, and a second light shielding member having a second pinhole into which the second reflected light is incident. The second movable body has a plurality of light incident points, and the first pinhole and the second pinhole are each the light incident point.

[0027] As a result, it is not necessary to provide a light source that also serves as a heat source such as a laser element in the second movable body. Since the temperature rise of the second movable body can be suppressed, a change in the refractive index of the air inside the second movable body can also be suppressed. Therefore, a change in the optical path length of the light used for measuring the measurement object can be suppressed, and a decrease in measurement accuracy can be suppressed.

[0028] The measuring device according to the fifth aspect of the present disclosure is a measuring device according to any one of the first to third aspects, wherein the second movable body includes a laser element including the light emission point and a beam splitter that separates the reflected light into a first reflected light and a second reflected light. The at least one optical fiber includes a second optical fiber having a second end into which the first reflected light is incident and a third optical fiber having a third end into which the second reflected light is incident. The second movable body has a plurality of light incident points, and the second end and the third end are each the light incident point.

[0029] As a result, instead of providing a member having a pinhole that is a light incident point and a photodetector, two optical fibers may be connected to the second movable body, so that the second movable body can be miniaturized and lightened.

[0030] The measuring device according to the sixth aspect of the present disclosure is the measuring device according to any one of the first to third aspects, wherein the second movable body has a beam splitter that divides the reflected light into first reflected light and second reflected light, the at least one optical fiber includes a first optical fiber, a second optical fiber having a second end portion into which the first reflected light is incident, and a third optical fiber having a third end portion into which the second reflected light is incident, the light emission point is the first end portion of the first optical fiber, the second movable body has a plurality of light incident points, and the second end portion and the third end portion are each the light incident point.

[0031] Thereby, miniaturization and weight reduction of the second movable body can be achieved. Further, deterioration of measurement accuracy due to heat generation can be suppressed.

[0032] The measuring device according to the seventh aspect of the present disclosure is the measuring device according to any one of the first to sixth aspects, wherein the at least one optical fiber includes a multi-core fiber including a plurality of cores, the second movable body has a plurality of light incident points, and each end portion of the plurality of cores is the light incident point.

[0033] Thereby, the number of optical fibers fixed to the second movable body can be reduced, so that miniaturization and weight reduction of the second movable body can be achieved.

[0034] The measuring device according to the eighth aspect of the present disclosure is the measuring device according to any one of the first to seventh aspects, wherein the at least one optical fiber is a single-mode fiber.

[0035] Thereby, since the light incident point or the light emission point can be made small, further miniaturization of the second movable body can be achieved.

[0036] The measuring device according to the ninth aspect of the present disclosure is a measuring device according to any one of the first to seventh aspects, wherein the at least one optical fiber is a multimode fiber.

[0037] This makes it easier to incident light on the optical fiber.

[0038] The measuring device according to the tenth aspect of the present disclosure is a measuring device according to any one of the first to ninth aspects, wherein the optical system includes a refractive index distribution type lens fixed to an end portion of the at least one optical fiber.

[0039] This enables miniaturization and weight reduction of the optical system, and thus miniaturization and weight reduction of the second movable body.

[0040] The measuring device according to the eleventh aspect of the present disclosure is a measuring device according to the first aspect or the tenth aspect, wherein the at least one optical fiber includes a multi-core fiber including a plurality of cores, and one end of the plurality of cores is the light incident point and also the light emission point.

[0041] This enables the optical fiber connected to the second movable body to be only one multi-core fiber. Therefore, it can contribute to miniaturization of the second movable body.

[0042] The measuring device according to the twelfth aspect of the present disclosure is a measuring device according to the fourth aspect or the sixth aspect, and includes a laser element. The light emitted from the laser element is incident from an end portion of the first optical fiber opposite to the first end portion, guided through the first optical fiber, and emitted from the first end portion.

[0043] This enables the laser element to be provided separately from the second movable body, making it easier to replace the laser element when it deteriorates. It is possible to suppress a decrease in the measurement accuracy of the measurement object due to the influence of heat generated when the laser element emits light.

[0044] The measuring device according to the thirteenth aspect of the present disclosure is a measuring device according to any one of the first aspect to the twelfth aspect, and includes a light intensity measuring unit that measures the intensity of the reflected light incident on the light incident point.

[0045] Thereby, since the light intensity measuring unit can be provided separately from the second movable body, it becomes easy to replace the light intensity measuring unit when it deteriorates.

[0046] Hereinafter, embodiments of the present disclosure will be specifically described with reference to the drawings.

[0047] Note that each of the embodiments described below shows general or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, components not described in the independent claims are described as optional components.

[0048] Also, each figure is a schematic diagram for explaining concepts only and does not show the actual size, shape, etc. Therefore, for example, the scales in each figure do not necessarily match. In each figure, substantially the same configuration is denoted by the same reference numeral, and overlapping descriptions are omitted or simplified.

[0049] In this specification, the light emission point is a portion where light is emitted into the second movable body and is a portion having a predetermined area. For example, the light emission point is the end of an optical fiber, the light emission surface of a light emitting element, or the like. The light incident point is a portion where the light propagated inside the second movable body is incident on the photodetector and is a portion having a predetermined area. For example, the light incident point is the end of an optical fiber, a pinhole, or the like.

[0050] In addition, in this specification, the "vertical direction" means the direction in which the relative position between the first movable body and the second movable body can change. Specifically, the direction parallel to the axis of the stylus of the first movable body is the vertical direction. The tip direction along the axis of the stylus is the "downward direction", and the opposite direction is the "upward direction". The tip of the stylus contacts the object to be measured.

[0051] In addition, in this specification, ordinal numbers such as "first" and "second" do not mean the number or order of components unless otherwise specified, and are used for the purpose of avoiding confusion and distinguishing between components of the same type.

[0052] (Embodiment 1) First, the measuring device according to Embodiment 1 will be described. The measuring device according to this embodiment has a configuration in which the end of an optical fiber connected to a light source is connected to a movable part instead of a laser light source provided in the movable part.

[0053] Hereinafter, the specific configuration of the measuring device according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram showing a schematic configuration of the measuring device according to this embodiment.

[0054] The measuring device 1 according to this embodiment is a three-dimensional shape measuring instrument. Specifically, the measuring device 1 measures the surface shape of an object to be measured (not shown). As shown in FIG. 1, the measuring device 1 includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and an optical fiber 16. In addition, the measuring device 1 includes a light source unit 20, photodetectors 31a and 31b, an interferometer 40, and an air supply unit 50.

[0055] [Probe] The probe 10 includes a movable part 11 and a movable part 12. The movable part 11 is an example of a first movable body having a reflector. The movable part 12 is an example of a second movable body having a light emission point, a light incidence point, and an optical system.

[0056] The movable part 11 includes a stylus 111, a slide part 112, and a mirror 113. The stylus 111 is fixed to the slide part 112. When measuring the object to be measured, the tip of the stylus 111 contacts the object to be measured. When the stylus 111 contacts the object to be measured, the movable part 11 changes its vertical position according to the shape of the object to be measured. The slide part 112 restricts the movement of the movable part 11 in the vertical direction. The mirror 113 is an example of a reflector included in the first movable body. The relative positional relationships among the stylus 111, the slide part 112, and the mirror 113 are fixed.

[0057] The movable part 12 includes a guide mechanism 120a and a probe housing 120b. The relative positional relationship between the guide mechanism 120a and the probe housing 120b is fixed. In the present embodiment, the movable part 12 has a light emission point 121, and light incident points 122a and 122b. The light emission point 121 is the end 161 of the optical fiber 16. The light incident point 122a is the first pinhole included in the light shielding member 128a. The light incident point 122b is the second pinhole included in the light shielding member 128b. Further, photodetectors 31a and 31b are provided on the movable part 12. The movable part 12 also has an optical system fixed to the probe housing 120b.

[0058] The optical system includes a collimator lens 123, a condenser lens 125 on the mirror 113 side, and condenser lenses 126 on the photodetectors 31a and 31b sides. The optical system also includes optical elements 124 and 129, and a beam splitter 127.

[0059] The collimator lens 123 converts the light emitted from the light emission point 121 into light that is nearly parallel (hereinafter referred to as parallel light). The light that is nearly parallel means light having a smaller divergence angle than the light before it enters the collimator lens 123, that is, the light emitted from the end 161 of the optical fiber 16 in the present embodiment.

[0060] The condensing lens 125 condenses the incident light in the vicinity of the mirror 113. For example, the condensing lens 125 passes through the collimator lens 123 and the optical element 124, and condenses the parallel light reflected by the optical element 129 in the vicinity of the mirror 113. Further, the condensing lens 125 converts the reflected light by the mirror 113 into parallel light, and makes it incident on the condensing lens 126 through the optical elements 129 and 124. Further, in the present embodiment, the condensing lens 125 condenses the light L used for measuring the measurement object in the vicinity of the mirror 113. Further, the condensing lens 125 converts the reflected light of the light L by the mirror 113 into parallel light, and makes it incident on the interferometer 40 through the optical element 129.

[0061] The condensing lens 126 condenses the incident light and makes it incident on the light incident points 122a and 122b.

[0062] The optical element 124 separates the light traveling from the light emission point 121, which is the end portion 161 of the optical fiber 16, toward the condensing lens 125, and the light traveling from the condensing lens 125 toward the condensing lens 126 (the reflected light by the mirror 113). The optical element 124 is, for example, a polarization beam splitter. The polarization beam splitter is an optical element having a dielectric multilayer film, reflects the light component having an electric field parallel to the dielectric multilayer film, and transmits the light component having an electric field orthogonal thereto.

[0063] For example, the component of the light emitted from the collimator lens 123 that passes through the dielectric multilayer film is used. Thereby, the light emitted from the collimator lens 123 can be made to pass through the optical element 124 and directed toward the condensing lens 125 side.

[0064] Also, by placing a λ / 4 waveplate on the optical path between the optical element 124, which is a polarization beam splitter, and the condenser lens 125, the λ / 4 waveplate can be passed through twice, once when the light travels from the optical element 124 toward the condenser lens 125 and once when the light travels from the condenser lens 125 toward the optical element 124. By appropriately selecting the angle of the λ / 4 waveplate, the electric field direction of the light traveling from the optical element 124 toward the condenser lens 125 side and the electric field direction of the light incident on the optical element 124 from the condenser lens 125 side can be rotated by 90 degrees. By rotating the electric field direction in this way, the optical element 124 can direct the light coming from the condenser lens 125 side toward the condenser lens 126 side. A polarizer or an element for controlling the electric field direction, such as a λ / 2 waveplate, may be placed between the collimator lens 123 and the optical element 124. Alternatively, the optical fiber 16 may be a polarization-maintaining fiber, and the direction of its end 161 may be set to a specific direction to control the electric field direction of the light emitted from the collimator lens 123.

[0065] The optical element 124 may be other than a polarization beam splitter. For example, a polarization-independent beam splitter may be used as the optical element 124. For example, when the optical element 124 is a beam splitter with a splitting ratio of 50:50, half of the light emitted from the collimator lens 123 and incident on the optical element 124 travels toward the condenser lens 125 side, and half of the light coming from the condenser lens 125 and incident on the optical element 124 travels toward the condenser lens 126 side. That is, approximately one-fourth of the light passing through the collimator lens 123 travels toward the condenser lens 126 side. Although this configuration has a light intensity loss compared to the configuration using a polarization beam splitter, the configuration can be simplified. Note that the splitting ratio of the beam splitter is not limited to 50:50, and other splitting ratios such as 10:90 or 30:70 may be used.

[0066] The optical element 129 is an optical element for superposing the optical path of the measurement light L used by the interferometer 40 and the optical path of the light for measuring the relative position between the movable part 11 and the movable part 12 and making them incident on the mirror 113. Further, the optical element 129 separates the reflected light that is reflected from the mirror 113 and passes through the condenser lens 125 into the reflected light for making it incident on the interferometer 40 and the reflected light for measuring the relative position between the movable part 11 and the movable part 12. The optical element 129 is, for example, a dichroic mirror, but it may also be a half mirror, a beam splitter cube, a polarization beam splitter cube, or the like.

[0067] For example, if the wavelength of the light L used by the interferometer 40 is made different from the wavelength of the light for measuring the relative position between the movable part 11 and the movable part 12, the optical paths of both lights can be combined and almost completely separated by an optical element having wavelength dependence such as a dichroic mirror. In the configuration of FIG. 1, as the optical element 129, a dichroic mirror that transmits the light L used by the interferometer 40 and reflects the light for measuring the relative position between the movable part 11 and the movable part 12 is used.

[0068] Alternatively, if the polarization of the light L used by the interferometer 40 is made different from the polarization of the light for measuring the relative position between the movable part 11 and the movable part 12, the optical paths of both lights can be combined and almost completely separated by an optical element having polarization dependence such as a polarization beam splitter cube. Further, when a configuration is adopted in which the optical path of the light used by the interferometer 40 and the optical path of the light for measuring the relative position between the movable part 11 and the movable part 12 are superposed using a non-polarizing beam splitter, an optical element that transmits one light and blocks the other light on the optical path where it is desired to separate both lights, for example, a notch filter, a band-pass filter, a long-pass filter, or a short-pass filter, may be arranged.

[0069] The beam splitter 127 separates the light that comes from the condenser lens 125 and passes through the condenser lens 126 into two. Specifically, the beam splitter 127 separates the reflected light reflected from the mirror 113 into a first reflected light and a second reflected light. More specifically, the beam splitter 127 intensity-divides the reflected light into a first reflected light and a second reflected light and emits them in different directions. The ratio of the intensity division by the beam splitter 127 is, for example, 1:1, but is not limited thereto.

[0070] In the present embodiment, the optical system included in the movable unit 12 may include a collimator lens 123 and, in addition to the condenser lenses 125 and 126, an optical element having optical power.

[0071] The movable unit 12 includes a light-shielding member 128a having a first pinhole located on the optical path of the first reflected light separated by the beam splitter 127, and a light-shielding member 128b having a second pinhole located on the optical path of the second reflected light. The first reflected light enters the first pinhole of the light-shielding member 128a, that is, the light incident point 122a. The second reflected light enters the second pinhole of the light-shielding member 128b, that is, the light incident point 122b. The distance from the principal point of the condenser lens 126 is different between the first pinhole that is the light incident point 122a and the second pinhole that is the light incident point 122b.

[0072] The relative position of the movable unit 12 with respect to the movable unit 11 is variable. The guide mechanism 120a of the movable unit 12 restricts the movement of the movable unit 11 in the vertical direction. An air supply unit 50 is connected to the movable unit 11. The movement of the movable unit 11 can be smoothly performed by the air supplied from the air supply unit 50.

[0073] In this embodiment, the movable part 11 and the movable part 12 are connected by a spring 15. The spring 15 is an example of an elastic body provided in the measuring device 1. The spring 15 applies a force in the direction of pressing the movable part 11 against the object to be measured (specifically, the downward direction) to the movable part 11. Thereby, the contact between the stylus 111 and the object to be measured is easily ensured, and the reliability of the measurement can be improved.

[0074] Instead of the spring 15, the measuring device 1 may be provided with rubber, which is another example of an elastic body. Further, the measuring device 1 may not be provided with an elastic body. For example, the movable part 11 and the movable part 12 may be connected by a mechanism using a magnet or the like.

[0075] [Drive mechanism] The drive mechanism 13 adjusts the position of the movable part 12. Specifically, the drive mechanism 13 receives a control signal from the control unit 14 and changes the position of the movable part 12. The drive mechanism 13 is, for example, a linear motor or the like, but is not particularly limited as long as it can adjust the position of the movable part 12.

[0076] [Control unit] The control unit 14 controls the drive mechanism 13. The control unit 14 is a control signal generation unit that generates a control signal to be output to the drive mechanism 13.

[0077] Specifically, the control unit 14 adjusts the position of the movable part 12 by controlling the drive mechanism 13 based on the intensity of the reflected light incident on the light incident point. More specifically, the control unit 14 calculates the relative position between the movable part 11 and the movable part 12 based on the output signals from the photodetectors 31a and 31b. The control unit 14 calculates the distance and direction by which the movable part 12 should be moved in order to keep the calculated relative position within a specified range. Then, the control unit 14 transmits a control signal for moving the movable part 12 by the calculated distance in the calculated direction to the drive mechanism 13. The method for calculating the relative position between the movable part 11 and the movable part 12 will be described later.

[0078] [Optical fiber] The optical fiber 16 is an example of a first optical fiber and has an end portion 161 and an end portion 162.

[0079] The end portion 161 is an example of a first end portion and is the light emission point 121 of the movable portion 12. The end portion 161 is directly fixed to the probe housing 120b which is a component of the probe 10 or fixed via other components.

[0080] The end portion 162 is the end portion of the optical fiber 16 on the side opposite to the end portion 161. The end portion 162 is not fixed to the probe housing 120b. The end portion 162 is connected to the light source unit 20, and light from the light source unit 20 is incident thereon. The light emitted from the light source unit 20 is incident from the end portion 162 of the optical fiber 16, guided through the optical fiber 16, and emitted from the end portion 161.

[0081] Note that the optical fiber 16 may be a fiber laser in which the optical fiber itself emits light. Alternatively, the optical fiber 16 may have a wavelength conversion function, such as a fluorescent fiber or a nonlinear optical fiber. In this case, the optical fiber 16 may emit only the light after wavelength conversion or both the light before wavelength conversion and the light after wavelength conversion. Thus, the optical fiber 16 and the light source unit 20 may be integrated.

[0082] The optical fiber 16 may be a single-mode fiber or a multi-mode fiber. When the optical fiber 16 is a single-mode fiber, the light emission point 121 can be made small. By making the light emission point 121 small, an optical path with small divergence can be created by the optical system of the movable portion 12. Thereby, it becomes easy to configure a system in which the change in the amount of light of the photodetectors 31a and 31b is sensitive to the change in the relative position between the movable portion 11 and the movable portion 12. When the optical fiber 16 is a multi-mode fiber, there is an advantage that the light emitted from the light source unit 20 is easily incident on the end portion 162 of the optical fiber 16. Therefore, it is advantageous from the viewpoint of the signal-to-noise ratio.

[0083] [Light source unit] The light source unit 20 emits light that can be detected by the photodetectors 31a and 31b. Although there is no particular limitation on the wavelength of the light emitted by the light source unit 20, if the wavelength is made different from the light used in the interferometer 40, separation of the two can be facilitated by an optical element 129 such as a dichroic mirror.

[0084] As shown in FIG. 1, the light source unit 20 includes a laser element 21 and an optical system 22. The laser element 21 is, for example, a semiconductor laser. Since the laser element 21 is a light source with a small emission point, it is easy for light to enter the end portion 162 of the optical fiber 16. The optical system 22 is an optical element for causing the light emitted from the laser element 21 to enter the end portion 162 of the optical fiber 16. Note that the light source unit 20 may not include the optical system 22.

[0085] [Photodetector] The photodetector 31a is an example of a light intensity measurement unit that measures the intensity of the first reflected light incident on the light incident point 122a. The photodetector 31b is an example of a light intensity measurement unit that measures the intensity of the second reflected light incident on the light incident point 122b. The photodetectors 31a and 31b are each, for example, a photoelectric conversion element such as a photodiode or a phototransistor.

[0086] The photodetector 31a detects the light that has passed through the first pinhole, that is, the first reflected light incident on the light incident point 122a. The photodetector 31a measures the intensity of the detected first reflected light and outputs a signal corresponding to the measured intensity to the control unit 14. The photodetector 31b detects the light that has passed through the second pinhole, that is, the second reflected light incident on the light incident point 122b. The photodetector 31b measures the intensity of the detected second reflected light and outputs a signal corresponding to the measured intensity to the control unit 14.

[0087] [Interferometer] The interferometer 40 measures the position of the mirror 113 of the movable part 11 of the probe 10 using light L. The position of the mirror 113 is fixed relative to the stylus 111. Since the position of the stylus 111 that contacts the measurement object changes along the shape of the measurement object, the shape of the measurement object can be measured by measuring the position of the mirror 113.

[0088] The interferometer 40 uses, for example, a wavelength-stabilized He-Ne laser or a frequency-stabilized semiconductor laser as the light source of the light L for measurement. Note that the probe 10 may separately include a mirror that reflects the light L for the interferometer 40 and a mirror that reflects the light for measuring the relative position between the movable part 11 and the movable part 12.

[0089] [Method for Controlling the Relative Position between the Movable Part 11 and the Movable Part 12] Next, a method for controlling the relative position between the movable part 11 and the movable part 12 will be described.

[0090] The light emitted from the light source unit 20 enters the optical fiber 16 from the end portion 162, is guided through the optical fiber 16, and then exits from the end portion 161 which is the light exit point 121. The light emitted from the light exit point 121 is converted by the collimator lens 123 into light that is nearly parallel (hereinafter referred to as parallel light) and propagates within the probe housing 120b. Specifically, the parallel light from the collimator lens 123 passes through the optical element 124, is reflected by the optical element 129, and enters the condenser lens 125.

[0091] The parallel light is converted by the condenser lens 125 into light that converges near the mirror 113 and is reflected by the mirror 113. The light reflected by the mirror 113 passes through the condenser lens 125 again and becomes light that is nearly parallel (hereinafter referred to as reflected light). The reflected light propagates within the probe housing 120b, and the optical element 124 changes the direction to a direction different from the incident direction and enters the condenser lens 126. The reflected light is converted into converging light by the condenser lens 126.

[0092] The condensing light is separated by the beam splitter 127 into two lights, i.e., a first reflected light and a second reflected light. Here, on the optical paths of the first reflected light and the second reflected light respectively, a first pinhole of the light shielding member 128a and a second pinhole of the light shielding member 128b are arranged. The light intensity of the light passing through each pinhole is measured by the photodetectors 31a and 31b placed behind the first pinhole and the second pinhole respectively.

[0093] The distance from the principal point of the condenser lens 126 to the first pinhole which is the light incident point 122a is different from the distance from the principal point of the condenser lens 126 to the second pinhole which is the light incident point 122b. The amount of light passing through the pinhole, i.e., the amount of light incident on the light incident point, depends on the distance between the condensing position of the condenser lens 126 and the position of the pinhole (i.e., the light incident point). Specifically, the closer the pinhole (i.e., the light incident point) is to the condensing position of the condenser lens 126, the more the amount of passing light.

[0094] The condensing position of the condenser lens 126 depends on the relative position between the condenser lens 125 on the mirror 113 side and the mirror 113. Therefore, for example, the control unit 14 transmits a control signal for moving the movable part 12 so that the intensity of the light measured by the photodetector 31a is always maximum to the drive mechanism 13. Thereby, if the position of the movable part 12 is adjusted, the relative position between the movable part 11 and the movable part 12 can be made constant. Alternatively, the relative position of the movable part 12 may be adjusted via the drive mechanism 13 by the control unit 14 so that the difference between the light intensity measured by the photodetector 31a and the light intensity measured by the photodetector 31b becomes 0.

[0095] [Regarding the effects] Subsequently, the effects of the measuring device 1 according to the present embodiment will be described while comparing with the conventional optical probe 10x shown in FIG. 6.

[0096] Specifically, in the conventional example, for measuring the relative position between the movable part 11x and the movable part 12x, the light from the semiconductor laser 21x fixed to the movable part 12x is used. In contrast, the measuring device 1 uses the light emitted from the end 161 of the optical fiber 16. The advantages of such a configuration will be described.

[0097] The first advantage is the miniaturization and weight reduction of the movable part 12.

[0098] Generally, the semiconductor laser 21x is housed in a package having a metal casing and a glass window with a size of about several millimeters in order to suppress deterioration due to the atmosphere or the like. On the other hand, a metal casing and a glass window are not required at the end 162 of the optical fiber 16 which is the light emission point 121. Therefore, by omitting these, the weight of the movable part 12 can be reduced.

[0099] Also, regarding the size, in the case of the optical fiber 16, the diameter of the end 161 can be set to 1 mm or less. Therefore, by using the end 162 of the optical fiber 16 as the light emission point 121 instead of the semiconductor laser 21x, the size of the movable part 12 can be reduced.

[0100] In addition, the optical fiber 16 has high symmetry and emits light from a circular cross-section with a small diameter. In particular, in the case of a single-mode fiber, its cross-section is extremely small. Therefore, the optical fiber 16 can emit light with a uniform spatial mode. Therefore, even when the light emitted from the optical fiber 16 is converted into collimated light with a small diameter using a small and lightweight lens with a short focal length as the collimator lens 123, divergence can be suppressed.

[0101] When the diameter of the light can be reduced, it becomes possible to reduce the size of each component such as lenses, prisms, and mirrors included in the optical system fixed to the movable part 12. Therefore, the entire optical system can be miniaturized and lightweight, contributing to the miniaturization of the movable part 12.

[0102] In addition, the optical system included in the movable part 12 may include a GRIN (Graded-Index) lens fixed to the end 161 of the optical fiber 16. By using the GRIN lens, it is also possible to omit the collimator lens 123, and the movable part 12 can be further reduced in size and weight.

[0103] Light with aligned spatial modes can be focused in a smaller range. This means that a pinhole with a smaller hole diameter can be used as a pinhole for detecting the relative position between the movable part 11 and the movable part 12. Alternatively, it means that the focal length of the lens that focuses light toward the pinhole can be reduced. Therefore, these also contribute to the reduction in size and weight of the movable part 12.

[0104] On the other hand, the conventional semiconductor laser 21x as a light source emits light that spreads spatially and is asymmetric in the vertical and horizontal directions. Therefore, divergence easily occurs in collimated light with a small diameter, and it is difficult to miniaturize an optical system such as a lens.

[0105] The second advantage is the reduction of wiring.

[0106] In order to operate the semiconductor laser 21x, it is necessary to connect it to a power supply using separate electric wires for the anode and the cathode respectively. That is, at least two electric wires need to be connected to the semiconductor laser 21x fixed to the movable part 12. If an output monitor installed inside a general semiconductor laser 21x is also used, one more electric wire is required. The more electric wires are connected to the movable part 12, the more difficult it is to miniaturize the movable part 12.

[0107] In contrast, in the present embodiment, the light source unit 20 is provided separately from the movable part 12. Only one optical fiber 16 needs to be connected to the movable part 12 for light emission. Therefore, the movable part 12 can be miniaturized.

[0108] The third advantage is the reduction of heat generation.

[0109] In the semiconductor laser 21x, only less than half of the consumed power is converted into light. The remaining power is dissipated as heat. The waste heat from the semiconductor laser 21x fixed to the movable part 12 causes a temperature rise inside the movable part 12. The temperature rise inside the movable part 12 varies the refractive index of the internal air and generates so-called fluctuations. Since the light L of the distance measuring mechanism for measuring the shape of the measurement object also passes through the movable part 12, this fluctuation has an adverse effect on the accuracy of measuring the shape of the measurement object.

[0110] On the other hand, in the present embodiment, the light source unit 20, which is the main heat generation source, is not provided in the movable part 12. In the optical fiber 16 connected to the movable part 12, the heat generation of the part fixed to the movable part 12 can be almost ignored. Therefore, the influence of heat can be greatly reduced, and a decrease in the accuracy of measuring the measurement object can be suppressed.

[0111] The fourth advantage is the ease of replacement.

[0112] The semiconductor laser 21x generally has a lifespan of about 10,000 hours. This lifespan corresponds to about one year when continuously lit. When the semiconductor laser 21x deteriorates, it becomes difficult to measure the relative position between the movable part 11 and the movable part 12, so the semiconductor laser 21x needs to be replaced.

[0113] When the semiconductor laser 21x is fixed to the movable part 12, each time replacement is performed, adjustment work of the optical system fixed to the movable part 12 is required. Since the optical system of the movable part 12 is also partially shared by the interferometer 40 for measuring the shape of the measurement object, careful attention is required for the adjustment.

[0114] On the other hand, in the present embodiment, the laser element 21 is arranged separately from the movable part 12. In this case, even if the laser element 21 is replaced, only adjustment of the coupling optical system with the optical fiber 16 needs to be performed. Therefore, the replacement adjustment work can be made easier.

[0115] (Embodiment 2) Next, the measuring device according to Embodiment 2 will be described. The measuring device according to the present embodiment has a configuration in which the end of an optical fiber connected to a photodetector is connected to the movable part, instead of the photodetector provided in the movable part.

[0116] Hereinafter, the specific configuration of the measuring device according to the present embodiment will be described with reference to FIG. 2. FIG. 2 is a diagram showing the schematic configuration of the measuring device according to the present embodiment. In the following, detailed descriptions of the parts common to Embodiment 1 will be omitted or simplified, and the description will focus on the differences from Embodiment 1.

[0117] As shown in FIG. 2, the measuring device 2 according to the present embodiment includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and optical fibers 17 and 18. The measuring device 2 also includes a laser element 21, photodetectors 31a and 31b, and an interferometer 40.

[0118] [Probe] The probe 10 includes a movable part 11 and a movable part 12. Since the configuration of the movable part 11 is the same as that of Embodiment 1, the description thereof will be omitted.

[0119] The movable part 12 includes a guide mechanism 120a and a probe housing 120b. The configurations of the guide mechanism 120a and the probe housing 120b are the same as those of Embodiment 1. Note that the shapes and sizes of the guide mechanism 120a and the probe housing 120b may be appropriately changed according to elements provided in the movable part 12 or cables connected thereto.

[0120] The movable part 12 also has a light emission point 121, and light incident points 122a and 122b. In the present embodiment, the specific configurations of each of the light emission point 121 and the light incident points 122a and 122b are different from those of Embodiment 1. Specifically, the light emission point 121 is the light emission surface of the laser element 21. The light incident point 122a is the end 171 of the optical fiber 17. The light incident point 122b is the end 181 of the optical fiber 18.

[0121] The movable part 12 has an optical system fixed to the probe housing 120b. The optical system is the same as that in the first embodiment. Specifically, the optical system includes a collimator lens 123, an optical element 124, a condenser lens 125, a condenser lens 126, a beam splitter 127, and an optical element 129. In this embodiment, the movable part 12 is not provided with light shielding members 128a and 128b.

[0122] [Optical fiber] The optical fiber 17 is an example of a second optical fiber and has an end 171 and an end 172.

[0123] The end 171 is an example of a second end and is a light incident point 122a where the first reflected light is incident. The end 171 is fixed to the probe housing 120b directly or via other components.

[0124] The end 172 is the end of the optical fiber 17 on the side opposite to the end 171. The end 172 is not fixed to the probe housing 120b. The end 172 is connected to, for example, a photodetector 31a. The end 172 emits the first reflected light that is incident from the end 171 and guided through the optical fiber 17 to the photodetector 31a.

[0125] The optical fiber 18 is an example of a third optical fiber and has an end 181 and an end 182.

[0126] The end 181 is an example of a third end and is a light incident point 122b where the second reflected light is incident. The end 181 is fixed to the probe housing 120b directly or via other components.

[0127] The end 182 is the end of the optical fiber 18 on the side opposite to the end 181. The end 182 is not fixed to the probe housing 120b. The end 182 is connected to, for example, a photodetector 31b. The end 182 emits the second reflected light that is incident from the end 181 and guided through the optical fiber 18 to the photodetector 31b.

[0128] Optical fibers 17 and 18 may each be a single-mode fiber or a multi-mode fiber. A multi-mode fiber is advantageous for obtaining a sufficient amount of light.

[0129] Also, polarization-maintaining fibers may be used for optical fibers 17 and 18. By using polarization-maintaining fibers, it becomes easy to separate the light used by the interferometer 40 from the light for measuring the relative positions of the movable part 11 and the movable part 12 using polarization optical elements.

[0130] In the movable part 12, the end 171 of the optical fiber 17 is disposed on the optical path of the first reflected light separated by the beam splitter 127. Also, the end 181 of the optical fiber 18 is disposed on the optical path of the second reflected light separated by the beam splitter 127. The distance from the principal point of the condenser lens 126 is different between the end 171 (light incident point 122a) of the optical fiber 17 and the end 181 (light incident point 122b) of the optical fiber 18.

[0131] [Laser element] The laser element 21 is fixed to the movable part 12. The laser element 21 includes the light emission point 121. Specifically, the light emission surface of the laser element 21 is the light emission point 121. The laser element 21 is, for example, a semiconductor laser.

[0132] [Photodetector] The photodetector 31a is an example of a light intensity measurement unit that measures the intensity of the first reflected light incident on the light incident point 122a. The photodetector 31b is an example of a light intensity measurement unit that measures the intensity of the second reflected light incident on the light incident point 122b. The photodetectors 31a and 31b are each a photoelectric conversion element such as a photodiode or a phototransistor, for example.

[0133] In the present embodiment, the photodetector 31a measures the intensity of the first reflected light that is incident from the end 171, guided through the optical fiber 17, and emitted from the end 172. The photodetector 31a outputs a signal corresponding to the measured intensity to the control unit 14.

[0134] The photodetector 31b measures the intensity of the second reflected light that is incident from the end portion 181, guided through the optical fiber 18, and emitted from the end portion 182. The photodetector 31b outputs a signal corresponding to the measured intensity to the control unit 14.

[0135] [Method for Controlling the Relative Position between the Movable Part 11 and the Movable Part 12] Next, a method for controlling the relative position between the movable part 11 and the movable part 12 will be described. Since the basic principle is the same as that in the first embodiment, the description will focus on the different parts.

[0136] The distance from the principal point of the condenser lens 126 to the end portion 171 of the optical fiber 17 is different from the distance from the principal point of the condenser lens 126 to the end portion 181 of the optical fiber 18. The amount of light incident from the end portion of the optical fiber into the optical fiber increases as the end portion is closer to the focusing position of the condenser lens 126. The focusing position of the condenser lens 126 depends on the relative position between the condenser lens 125 on the mirror 113 side and the mirror 113.

[0137] Therefore, for example, the control unit 14 transmits a signal to the drive mechanism 13 to move the movable part 12 so that the intensity of the first reflected light measured by the photodetector 31a is always maximized. By adjusting the position of the movable part 12 in this way, the relative position between the movable part 11 and the movable part 12 can be made constant. Alternatively, the control unit 14 may adjust the relative position of the movable part 12 via the drive mechanism 13 so that the difference between the light intensity measured by the photodetector 31a and the light intensity measured by the photodetector 31b becomes zero.

[0138] [Regarding the Effects] Subsequently, the effects of the measuring device 2 according to the present embodiment will be described while comparing with the conventional optical probe 10x shown in FIG. 6.

[0139] Specifically, in the conventional example, photodetectors 31ax and 31bx fixed to the movable part 12x are used to measure the relative positions of the movable part 11x and the movable part 12x. In contrast, in the measuring device 2, each of the end 171 of the optical fiber 17 and the end 181 of the optical fiber 18 is used as the light incident points 122a and 122b, and the photodetectors 31a and 31b are arranged outside the movable part 12. The advantages of such a configuration will be described.

[0140] The first advantage is the miniaturization of the movable part 12, which is the same as in the first embodiment.

[0141] Similar to the case of the semiconductor laser 21x, the photodetectors 31ax and 31bx also need to be about several millimeters in diameter for sealing. In contrast, in the present embodiment, the photodetectors 31a and 31b are arranged separately from the movable part 12, and the ends 171 of the optical fiber 17 and the ends 181 of the optical fiber 18 are connected to the movable part 12. Therefore, similar to the first embodiment, the movable part 12 can be miniaturized and lightened. Also, in the present embodiment, the light-shielding member having a pinhole can be omitted. Therefore, further miniaturization and weight reduction are possible.

[0142] The second advantage is the reduction of wiring. This is also the same as in the first embodiment.

[0143] (Embodiment 3) Subsequently, the measuring device according to the third embodiment will be described. The measuring device according to the present embodiment is different from the measuring devices according to the first and second embodiments in that neither a photodetector nor a laser element is provided in the movable part. Specifically, in the present embodiment, the light incident point and the light emission point are each the end of the optical fiber.

[0144] Hereinafter, the specific configuration of the measuring device according to the present embodiment will be described with reference to FIG. 3. FIG. 3 is a diagram showing the schematic configuration of the measuring device according to the present embodiment. In the following, detailed descriptions of parts common to Embodiment 1 or 2 will be omitted or simplified, and the description will focus on the differences from Embodiment 1 or 2.

[0145] As shown in FIG. 3, compared with the measuring device 2 according to Embodiment 2, the measuring device 3 according to the present embodiment is different in that it includes an optical fiber 16 and a light source unit 20 instead of the laser element 21. The optical fiber 16 and the light source unit 20 are the same as those of the measuring device 1 according to Embodiment 1. That is, the measuring device 3 according to the present embodiment has a configuration combining the measuring device 1 shown in FIG. 1 and the measuring device 2 shown in FIG. 2.

[0146] Specifically, in the measuring device 3, the light emission point 121 is the end 161 of the optical fiber 16. The light incident points 122a and 122b are the ends 171 of the optical fiber 17 and the end 181 of the optical fiber 18, respectively.

[0147] As a result, it is not necessary to provide the laser element 21, the photodetectors 31a and 31b, and the light shielding members 128a and 128b on the movable part 12. It is not necessary to wire the power lines and signal lines connected to the laser element 21 and the photodetectors 31a and 31b on the movable part 12. Therefore, further miniaturization and weight reduction are possible compared with the conventional configuration. In addition, the first to fourth advantages described in Embodiments 1 and 2 can be obtained.

[0148] (Embodiment 4) Subsequently, the measuring device according to Embodiment 4 will be described. The measuring device according to the present embodiment has a configuration in which a bundle fiber in which a plurality of cores are bundled is connected to a movable part.

[0149] Hereinafter, the specific configuration of the measuring device according to the present embodiment will be described with reference to FIG. 4. FIG. 4 is a diagram showing the schematic configuration of the measuring device according to the present embodiment. In the following, detailed descriptions of the parts common to Embodiments 1 and 2 will be omitted or simplified, and the description will focus on the differences from Embodiment 1 or 2.

[0150] As shown in FIG. 4, the measuring device 4 according to the present embodiment includes a probe 10, a drive mechanism 13, a control unit 14, a spring 15, and a bundle fiber 19. The measuring device 4 also includes a laser element 21, photodetectors 31a and 31b, and an interferometer 40. Note that, similar to Embodiment 1 or 3, the measuring device 4 may include an optical fiber 16 and a light source unit 20 instead of the laser element 21.

[0151] [Probe] The probe 10 includes a movable part 11 and a movable part 12. Since the configuration of the movable part 11 is the same as that in Embodiment 1, the description thereof will be omitted.

[0152] The movable part 12 includes a guide mechanism 120a and a probe housing 120b. The configurations of the guide mechanism 120a and the probe housing 120b are the same as those in Embodiment 1. Note that the shapes and sizes of the guide mechanism 120a and the probe housing 120b may be appropriately changed according to elements provided in the movable part 12 or cables connected thereto.

[0153] The movable part 12 also has a light emission point 121 and a light incidence point 122. The light emission point 121 is the light emission surface of the laser element 21, similar to Embodiment 2. In the present embodiment, the specific configuration of the light incidence point 122 is different from that in Embodiment 2. Specifically, the light incidence point 122 is the end 191 of the bundle fiber 19.

[0154] The movable part 12 has an optical system fixed to the probe housing 120b. The optical system is different in that it does not include the beam splitter 127 as compared with the first embodiment. Specifically, the optical system includes a collimator lens 123, an optical element 124, a condenser lens 125, a condenser lens 126, and an optical element 129.

[0155] [Bundle fiber] The bundle fiber 19 is an example of an optical fiber and is a multi-core fiber including a plurality of cores. Each core of the bundle fiber 19 can transmit different light.

[0156] FIG. 5 is a diagram showing the concept of the bundle fiber. The bundle fiber 19 shown in FIG. 5 includes seven cores 19A, 19B, 19C, 19D, 19E, 19F, and 19G. Note that the number of cores may be plural and is not particularly limited. For example, at one end of the bundle fiber 19, a plurality of cores are bundled, and at the other end, at least one of the plurality of cores is separated. The end portion in a state where a plurality of cores are bundled allows the cores to be arranged in a narrow space region. The end portion in a state where a plurality of cores are separated allows an individual photodetector to be connected to each core. Alternatively, a plurality of end portions can be collectively connected to one photodetector.

[0157] In the present embodiment, the end portion 191 in a state where a plurality of cores of the bundle fiber 19 are bundled is fixed near the condensing point of the condenser lens 126 of the probe housing 120b as shown in FIG. 4.

[0158] The end of the bundle fiber 19 in a state where the cores are separated is not fixed to the movable part 12, and a photodetector is connected. Instead of connecting a photodetector independently for each core, one photodetector may be connected to a plurality of cores. For example, at the end 191 where seven cores 19A, 19B, 19C, 19D, 19E, 19F, and 19G are bundled, the other end corresponding to the core 19A existing in the central part is connected to the photodetector 31a. The ends corresponding to the cores 19B, 19C, 19D, 19E, 19F, and 19G located around the core 19A are connected to the photodetector 31b.

[0159] [Photodetector] In the present embodiment, at least two photodetectors are provided. Specifically, as shown in FIG. 4, the photodetectors 31a and 31b respectively measure the intensity of the light transmitted by another core of the bundle fiber 19. More specifically, the photodetector 31a measures the intensity of the reflected light incident on the core 19A at the center of the end 191 of the bundle fiber 19. The photodetector 31b measures the total intensity of the reflected light incident on each of the six cores 19B, 19C, 19D, 19E, 19F, and 19G around the end 191 of the bundle fiber 19.

[0160] [Method for Controlling the Relative Position between the Movable Part 11 and the Movable Part 12] Next, a method for controlling the relative position between the movable part 11 and the movable part 12 will be described.

[0161] In the plane where the end 191 of the bundle fiber 19 exists, the cross-sectional distribution of the light intensity formed by the condenser lens 126 varies depending on the focusing position of the condenser lens 126. Specifically, the closer the focusing position of the condenser lens 126 is, the more the light intensity is concentrated in the central part and attenuates in the peripheral part. The focusing position of the condenser lens 126 depends on the relative position between the condenser lens 125 on the mirror 113 side and the mirror 113.

[0162] Therefore, at the end portion 191 of the bundle fiber 19, by comparing the light intensity incident on the core 19A at the center and the light intensity incident on at least one of the cores 19B, 19C, 19D, 19E, 19F, and 19G at the peripheral portion, it is possible to know how close the condensing position is to the end portion 191 of the bundle fiber 19.

[0163] For example, when the position of the movable portion 12 is slightly shifted by controlling the drive mechanism 13, if the ratio of the light intensity incident on the core 19A at the center to the light intensity incident on the cores 19B, 19C, 19D, 19E, 19F, and 19G at the peripheral portion increases, it can be known that the condensing position has approached the end portion 191 of the bundle fiber 19. Conversely, if the light intensity ratio decreases, it can be known that the condensing position has moved away from the end portion 191 of the bundle fiber 19.

[0164] The position where the condensing lens 126 condenses light most depends on the relative positions of the movable portion 11 and the movable portion 12. Therefore, by knowing the ratio of the amount of light incident on each core, the control unit 14 can calculate the relative position between the movable portion 11 and the movable portion 12. The control unit 14 calculates the moving direction and the moving distance of the movable portion 12 so that the calculated relative position approaches a specified value. Then, the control unit 14 can adjust the position of the movable portion 12 by the drive mechanism 13 by transmitting a control signal to the drive mechanism 13.

[0165] An advantage of the present embodiment is that there is only one end portion of the optical fiber to be fixed to the movable portion 12. For this reason, it is possible to reduce the size and weight of the movable portion 12. In addition, in a configuration in which a plurality of cores exist in the peripheral portion, if an independent photodetector is connected to each core, information on the inclination of the mirror 113 can also be obtained.

[0166] Note that, in the measuring apparatus 4 according to the present embodiment, similar to the first or third embodiment, instead of the laser element 21, a light source unit 20 and an optical fiber 16 may be provided. Thereby, the first to fourth advantages described in the first embodiment can be obtained.

[0167] In addition, the bundle fiber 19 may be used as an optical fiber for emitting light into the movable part 12. For example, the central core 19A may be used not only for guiding the reflected light but also for guiding the light from the laser element 21. In this case, the end 191 of the bundle fiber 19 is the light emission point 121 and also the light incident point 122. That is, the light emission point 121 and the light incident point 122 may be the same.

[0168] In this case, an optical element for controlling the traveling direction of light, such as a circulator, is connected to the end of the central core 19A on the side opposite to the end 191. Thereby, the light from the laser element 21 can be made to enter the core 19A and exit from the end 191, and the reflected light incident from the end 191 can be made to travel toward the photodetector 31a after guiding through the core 19A.

[0169] (Other embodiments) As described above, the measuring device according to one or more aspects has been described based on the embodiments. However, the present disclosure is not limited to these embodiments. As long as the gist of the present disclosure is not deviated from, various modifications conceived by those skilled in the art applied to these embodiments, and forms constructed by combining the components in different embodiments are also included within the scope of the present disclosure.

[0170] For example, in the measuring device according to each embodiment, the movable part 11 and the movable part 12 may not be connected at all. By utilizing the self-weight of the movable part 11, the relative position in the vertical direction between the movable part 11 and the movable part 12 may be variable. In this case, by adjusting the posture of the measuring device so that the vertical direction coincides with the plumb direction, the self-weight of the movable part 11 can be effectively utilized. Note that a restricting portion such as a protrusion for restricting the position of the movable part 11 may be provided so that the movable part 11 does not separate from the movable part 12.

[0171] Further, the present disclosure may be implemented as a control system or a control method for a movable body included in a measuring device. The control system is realized by, for example, one or more computer devices. Specifically, the control system includes a control unit that controls a drive mechanism for adjusting the positions of a light emission point, a light incidence point, and a second movable body having an optical system. The light emission point or the light incidence point is an end portion of at least one optical fiber. The light emitted from the light emission point is irradiated onto a reflector of the first movable body through the optical system, and the reflected light reflected from the reflector is incident on the light incidence point. The control unit adjusts the position of the second movable body by controlling the drive mechanism based on the intensity of the reflected light incident on the light incidence point.

[0172] Further, the present disclosure may be implemented as a non-contact type measuring device. Specifically, when the first movable body of the measuring device measures a measurement object, it may not contact the measurement object. For example, the interferometer may be configured to irradiate light on the surface of the measurement object and receive the reflected light of the light from the measurement object.

[0173] Note that the one or more computer devices include, for example, a non-volatile memory storing a program, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. Further, the control system may be a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor in which the connection and setting of circuit cells in an LSI can be reconfigured. The functions executed by the control system may be realized by software or by hardware.

[0174] In addition, a method for controlling a movable body included in a measuring device includes a step of controlling a drive mechanism that adjusts the positions of a light emission point, a light incidence point, and a second movable body having an optical system. The light emission point or the light incidence point is an end portion of at least one optical fiber. The light emitted from the light emission point is irradiated onto a reflector included in the first movable body via the optical system, and the reflected light reflected from the reflector is incident on the light incidence point. In the control step, the position of the second movable body is adjusted by controlling the drive mechanism based on the intensity of the reflected light incident on the light incidence point.

[0175] In addition, the present disclosure may be implemented as a program for causing a computer to execute a method for controlling a movable body included in a measuring device. Further, the present disclosure may be implemented as a non-transitory recording medium storing the program.

[0176] In addition, various changes, replacements, additions, omissions, etc. can be made to each of the above embodiments within the scope of the claims or their equivalents.

Industrial Applicability

[0177] The present disclosure can be used in various measuring devices such as inspections of industrial products that require high-precision distance measurement.

Explanation of Signs

[0178] 1, 2, 3, 4 Measuring device 10 Probe 11, 12 Movable part 13 Drive mechanism 14 Control unit 15 Spring 16, 17, 18 Optical fiber 19 Bundle fiber 19A, 19B, 19C, 19D, 19E, 19F, 19G Core 20 Light source unit 21 Laser element 22 Optical system 31a, 31b Photodetector 40 Interferometer 50 Air supply unit 111 Stylus 112 Slide part 113 Mirror 120a Guide mechanism 120b Probe housing 121 Light emission point 122, 122a, 122b Light incident point 123 Collimator lens 124, 129 Optical element 127 Beam splitter 125, 126 Condensing lens 128a, 128b Light shielding member 161, 162, 171, 172, 181, 182, 191 End part

Claims

1. A first movable body having a reflector, A second movable body having a light emission point, a light incident point, and an optical system, A drive mechanism for adjusting the position of the second movable body, A control unit for controlling the drive mechanism, At least one optical fiber, and comprising, The light emitted from the light emission point is irradiated onto the reflector through the optical system, The reflected light reflected from the reflector is incident on the light incident point, The control unit adjusts the position of the second movable body by controlling the drive mechanism based on the intensity of the reflected light incident on the light incident point, The light emission point or the light incident point is an end of the at least one optical fiber, Measuring device.

2. When measuring an object, the first movable body contacts the object, The measuring device according to claim 1.

3. An elastic body for connecting the first movable body and the second movable body is provided, The measuring device according to claim 1.

4. The at least one optical fiber includes a first optical fiber, The light emission point is a first end of the first optical fiber, The second movable body, A beam splitter for separating the reflected light into first reflected light and second reflected light, A first light-shielding member having a first pinhole into which the first reflected light is incident, A second light-shielding member having a second pinhole into which the second reflected light is incident, and having, The second movable body has a plurality of light incident points, The first pinhole and the second pinhole are respectively the light incident points, The measuring device according to any one of claims 1 to 3.

5. The second movable body, A laser element including the light emission point, A beam splitter for separating the reflected light into first reflected light and second reflected light, and having, The at least one optical fiber, A second optical fiber having a second end into which the first reflected light is incident, A third optical fiber having a third end into which the second reflected light is incident, and including, The second movable body has a plurality of light incident points, The second end and the third end are respectively the light incident points, The measuring device according to any one of claims 1 to 3.

6. The second movable body has a beam splitter for splitting the reflected light into first reflected light and second reflected light, The at least one optical fiber, A first optical fiber, A second optical fiber having a second end into which the first reflected light is incident, A third optical fiber having a third end portion into which the second reflected light is incident, The light emission point is the first end portion of the first optical fiber, The second movable body has a plurality of light incident points, The second end portion and the third end portion are each the light incident point, The measuring device according to any one of claims 1 to 3.

7. The at least one optical fiber includes a multi-core fiber including a plurality of cores, The second movable body has a plurality of light incident points, Ends of each of the plurality of cores are each the light incident point, The measuring device according to any one of claims 1 to 3.

8. The at least one optical fiber is a single-mode fiber, The measuring device according to any one of claims 1 to 3.

9. The at least one optical fiber is a multi-mode fiber, The measuring device according to any one of claims 1 to 3.

10. The optical system includes a refractive index distribution type lens fixed to an end portion of the at least one optical fiber, The measuring device according to any one of claims 1 to 3.

11. The at least one optical fiber includes a multi-core fiber including a plurality of cores, One end of the plurality of cores is the light incident point and also the light emission point, The measuring device according to any one of claims 1 to 3.

12. Comprising a laser element, Light emitted from the laser element is incident from an end portion of the first optical fiber opposite to the first end portion, guided through the first optical fiber, and emitted from the first end portion, The measuring device according to claim 4.

13. Comprising a light intensity measuring unit that measures the intensity of the reflected light incident on the light incident point, The measuring device according to any one of claims 1 to 3.

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