Displacement sensor and profilometer

Abstract

To address the problem of suppressing changes in the period of a stripe detected by a light receiving section even if a workpiece is displaced, a displacement sensor 10 includes an irradiation section 20 that irradiates a workpiece W that is displaceable in a predetermined displacement direction with light, a light receiving section 30 that receives reflected light generated when the light irradiated by the irradiation section is reflected on the workpiece W, and a stripe generation section 40 that includes a generation structure for generating a stripe on a light receiving surface 32 of the light receiving section 30 when the light receiving section receives the reflected light from the workpiece, wherein the stripe generation section 40 and the light receiving section 30 are arranged so that the stripe generation section and the light receiving section are parallel to the displacement direction, or a virtual image parallel to the displacement direction.

Description

Technical Field

[0001] This disclosure relates to displacement sensors and contour measurement devices. Background Technology

[0002] Triangulation sensors are commonly used as displacement sensors for detecting workpiece displacement. In a triangulation sensor, light emitted from a light source in the radiating section is first reflected by the workpiece. The light reflected from the workpiece is then imaged onto the light-receiving surface (imaging surface) of the light-receiving section (e.g., the imaging element) by an imaging lens.

[0003] In the aforementioned triangulation sensor, the distribution of light received by the light receiver may be uneven, leading to positional changes. Therefore, to suppress the unevenness of light distribution, the technique disclosed in Patent Document 1 below can be considered. Patent Document 1 discloses a technique in which a grating is illuminated with light from a light source to generate stripes, and the phase of the stripes is detected by the light receiver to measure the position of the light source.

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 4503902 Summary of the Invention

[0006] The problem to be solved by the present invention

[0007] However, when the above technology is applied, the period of the stripes detected by the light receiver varies depending on the position of the workpiece. Therefore, when the workpiece is displaced, there is a deviation between the period of the detection element on the light receiver and the period of the stripes, resulting in reduced detection accuracy.

[0008] This disclosure focuses on these points, and the purpose of this disclosure is to suppress changes in the period of the stripes detected by the light receiver even when the workpiece is displaced.

[0009] Problem-solving methods

[0010] A first aspect of this disclosure provides a displacement sensor, comprising: a radiating section that illuminates a workpiece displaceable in a predetermined displacement direction with light; a light receiving section that receives reflected light generated when light radiated by the radiating section is reflected on the workpiece; and a stripe generating section that includes generating means for generating stripes on a light receiving surface of the light receiving section when the light receiving section receives reflected light from the workpiece, wherein the stripe generating section and the light receiving section are arranged such that the stripe generating section and the light receiving section are parallel to the displacement direction, or parallel to a virtual image of the displacement direction.

[0011] Furthermore, the stripe generating section may include a diffraction grating having multiple holes as generating devices, and may generate stripes on a light receiving surface using reflected light passing through the holes.

[0012] Furthermore, the stripe generating section may include a substrate on which multiple steps are formed as generating devices, and stripes may be generated on the light receiving surface by utilizing reflected light transmitted through the steps.

[0013] Furthermore, the stripe generating section may include a plurality of generating devices arranged at predetermined intervals, and the distance between the stripe generating section and the radiation plane of the radiating section may have the same length as the distance between the stripe generating section and the light receiving surface. The stripe generating section may include a diffraction grating having a plurality of holes as generating devices, the plurality of holes may be arranged at predetermined intervals, and the distance between the stripe generating section and the radiation plane of the radiating section may have the same length as the distance between the stripe generating section and the light receiving surface.

[0014] In addition, the stripe generation unit may include a plurality of image forming elements as a generation device, which are arranged in rows adjacent to each other along the displacement direction.

[0015] Furthermore, the fringe generating section may include a plurality of diffraction gratings arranged parallel to the displacement direction or virtual image, and having a plurality of holes formed therein as generating devices, and the spacing between the holes of the diffraction gratings may be different from each other.

[0016] In addition, the light receiving unit may include a photodiode array, in which multiple photodiodes for detecting reflected light are arranged.

[0017] Furthermore, the generating devices can be arranged such that the spacing between adjacent generating devices along the displacement direction is random. The fringe generating section may include a diffraction grating in which a plurality of holes serving as generating devices are formed, and the plurality of holes can be arranged such that the spacing between adjacent holes is random.

[0018] In addition, the displacement sensor also includes a reflective member that reflects reflected light from the workpiece toward the stripe generating part, wherein the stripe generating part and the light receiving part can be arranged such that when viewed from the reflective member, the stripe generating part and the light receiving part are parallel to the virtual image of the displacement direction.

[0019] In addition, the radiating section can irradiate the workpiece with linear light, and the stripe generating section can generate stripes on the light receiving surface that can detect the position on two orthogonal axes.

[0020] A second aspect of this disclosure provides a contour measuring device, comprising: a displacement sensor including: a) a radiating section for irradiating a workpiece displaceable in a predetermined displacement direction with light; b) a light receiving section for receiving reflected light generated when light radiated from the radiating section is reflected on the workpiece; and c) a stripe generating section including generating means for generating stripes on a light receiving surface of the light receiving section when the light receiving section receives reflected light from the workpiece; and a calculation section for calculating the contour of the workpiece based on the output of the light receiving section, wherein the stripe generating section and the light receiving section can be arranged such that the stripe generating section and the light receiving section are parallel to the displacement direction, or parallel to a virtual image in the displacement direction.

[0021] Invention Effects

[0022] According to this embodiment, even when the workpiece is displaced, the change in the stripe period detected by the light receiving unit can be suppressed. Attached Figure Description

[0023] Figure 1 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the first embodiment.

[0024] Figure 2 It is used to explain the period d of the fringes when the workpiece W is displaced. D A schematic diagram.

[0025] Figure 3 This is a schematic diagram used to explain the displacement sensor 110 according to the comparative example.

[0026] Figure 4 This is a schematic diagram used to explain the configuration of the contour measuring device 1.

[0027] Figure 5 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the second embodiment.

[0028] Figure 6 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the third embodiment.

[0029] Figure 7 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the fourth embodiment.

[0030] Figure 8 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the fifth embodiment.

[0031] Figure 9 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the sixth embodiment.

[0032] Figure 10 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the seventh embodiment.

[0033] Figure 11 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the eighth embodiment.

[0034] Figure 12 This is a schematic diagram for explaining the configuration of the displacement sensor 10 according to the ninth embodiment. Detailed Implementation

[0035] <First Embodiment>

[0036] (Configuration of the displacement sensor)

[0037] Reference Figure 1 The configuration of the displacement sensor 10 according to the first embodiment is described.

[0038] Figure 1 This is a schematic diagram illustrating the configuration of the displacement sensor 10 according to the first embodiment. The displacement sensor 10 illuminates the workpiece W with light to measure the distance (displacement) to the workpiece W. The displacement sensor 10 is a triangulation sensor. Figure 1 As shown, the displacement sensor 10 includes a radiating part 20, a light receiving part 30, and a stripe generating part 40.

[0039] The radiating section 20 irradiates the workpiece W with light. For example, the radiating section 20 radiates linear light downward toward the workpiece W. The workpiece W is displaced in a vertical direction, which is a predetermined displacement direction. The radiating section 20 radiates light onto the workpiece W, and the workpiece W is displaced by moving vertically along the radiating plane 26. The radiating plane 26 is a plane that includes the optical axis of the light radiated by the radiating section 20.

[0040] The radiating section 20 includes a light source 22 and a lens 24. The light source 22 emits a laser beam with a predetermined wavelength. The lens 24 is, for example, a collimating lens or a rod lens, and radiates the light emitted from the light source 22 as linear light onto the workpiece W. The light radiated from the radiating section 20 is reflected by the workpiece W (specifically, at the radiating point P). Figure 1 As shown, the reflected light from workpiece W is scattered.

[0041] The light receiving unit 30 receives reflected light generated when light radiated by the radiating unit 20 is reflected onto the workpiece W. The light receiving unit 30 includes a light receiving surface 32 for receiving the reflected light (specifically, the stripes generated by the stripe generating unit 40 using the reflected light). The light receiving surface 32 receives the reflected light at a position corresponding to the distance (displacement) from the displacement sensor 10 to the workpiece W. Therefore, when the position on the light receiving surface 32 where the reflected light is received can be specified, the displacement of the workpiece W is detected. The light receiving surface 32 is positioned such that it is parallel to the displacement direction (vertical direction) of the workpiece W.

[0042] For example, the light receiver 30 is an image sensor for imaging stripes. As an example, the light receiver 30 includes a CMOS light receiver element.

[0043] The stripe generating unit 40 has a generating device for receiving reflected light from a workpiece W located at one position and generating stripes on the light receiving surface 32 of the light receiving unit 30. For example, the stripe generating unit 40 receives multiple reflected light stripes. Figure 1 The light is reflected from three beams and interference fringes are generated at multiple locations on the light-receiving surface 32. By generating fringes on the light-receiving surface 32, the non-uniformity of the light distribution can be suppressed, thus allowing for proper detection of the displacement of the workpiece W. The fringes are arranged with a predetermined period d. D It is generated on the light receiving surface 32.

[0044] Figure 2 It is used to explain the period d of the fringes when the workpiece W is displaced. D A schematic diagram. Figure 2 (a) shows workpiece W located at position X1. Figure 2 (b) shows workpiece W located at position X2. From Figure 2 As can be seen from (a) and 2(b), the position of the stripes on the light-receiving surface 32 shifts when the workpiece W moves from position X1 to position X2. On the other hand, even when the workpiece W moves from position X1 to position X2, the period d of the stripes... D They also have the same size.

[0045] Here, the fringe generating section 40 includes a diffraction grating 42. For example... Figure 1 As shown, a plurality of holes 44 are arranged at predetermined intervals in the diffraction grating 42. In this embodiment, the holes 44 correspond to the generating apparatus for generating fringes. The holes 44 are the transmissive portions through which reflected light from the workpiece W passes, and the portions of the diffraction grating 42 other than the holes 44 are the non-transmissive portions through which reflected light passes. The diffraction grating 42 generates interference fringes using diffraction.

[0046] like Figure 1 As shown, according to this embodiment, the fringe generating section 40 is arranged such that the diffraction grating 42 is parallel to the displacement direction (vertical direction) of the workpiece W. In other words, the fringe generating section 40 is arranged such that the diffraction grating 42 is parallel to the radiation plane 26 of the radiation section 20. Therefore, the diffraction grating 42 is also parallel to the light receiving surface 32 of the light receiving section 30. Here, a) the distance u between the fringe generating section 40 (diffraction grating 42) and the radiation point P (radiation plane 26) and b) the distance v between the fringe generating section 40 and the light receiving surface 32 are different.

[0047] In the first embodiment, the stripe generating section 40 and the light receiving section 30 are arranged parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced, the distance u between the radiation point P on the workpiece W and the stripe generating section 40 will not change. Consequently, even when the workpiece W is displaced, the period of the stripes generated on the light receiving surface 32 of the light receiving section 30 will not change.

[0048] Figure 3 This is a schematic diagram for explaining the displacement sensor 110 according to a comparative example. The displacement sensor 110 according to the comparative example includes a radiating section 120, a light receiving section 130, and a stripe generating section 140. The radiating section 120 has a similar shape to... Figure 1 The displacement sensor 10 is shown with its radiating section 20 arranged as described. However, the arrangement of the light receiving section 130 and the stripe generating section 140 relative to the workpiece W differs from the arrangement of the light receiving section 30 and the stripe generating section 40 of the displacement sensor 10 relative to the workpiece W. Specifically, the light receiving section 130 and the stripe generating section 140 are arranged orthogonally to the displacement direction of the workpiece W. This arrangement differs from the arrangement of the light receiving section 30 and the stripe generating section 40, which are arranged parallel to the displacement direction of the workpiece W.

[0049] In the configuration according to the comparative example, the period d of the stripes 134 generated on the light receiving surface 132 is... D It is represented by the following equation (1).

[0050]

[0051] In equation (1), u is the distance between the radiation point P and the fringe generating part 140, v is the distance between the fringe generating part 140 and the light receiving surface 132, and d G It is the lattice constant of diffraction grating 142.

[0052] In the comparative example, when the workpiece W is displaced in the displacement direction (vertical direction), the distance u between the radiation point P on the workpiece W and the stripe generating part 140 changes, therefore the period d of the stripe 134 changes. D The change is obvious from equation (1). As a result, there is a discrepancy between a) the period of the stripe 134 generated on the light-receiving surface 132 and b) the period of the detection element placed on the light-receiving surface 132, so the stripe 134 cannot be detected with high precision.

[0053] Conversely, in the displacement sensor 10 according to the first embodiment, the distance u between the radiation point P on the workpiece W and the stripe generating portion 40 does not change even when the workpiece W is displaced. The distance v between the stripe generating portion 40 and the light receiving surface 32 also does not change. Therefore, as... Figure 2As shown, the period of the stripes generated on the light-receiving surface 32 does not change even when the workpiece W is displaced. Therefore, since there is no deviation between the period of the stripes on the light-receiving surface 32 and the period of the detection element, the stripes can be accurately detected even when the workpiece W moves.

[0054] (Configuration of contour measurement equipment)

[0055] Reference Figure 4 The description includes the configuration of the contour measuring device 1 having the displacement sensor 10 configured as described above.

[0056] Figure 4 This is a schematic diagram illustrating the configuration of the contour measuring device 1. The contour measuring device 1 is used to measure the contour of the workpiece W based on the detection results of the displacement sensor 10. (As shown...) Figure 4 As shown, the contour measuring device 1 includes a displacement sensor 10 and a controller 90.

[0057] In the contour measuring device 1, the displacement sensor 10 is used as a non-contact optical probe to measure the position coordinates, etc., of each part of the workpiece W. The displacement sensor 10 is configured as described above. Figure 1 The configuration shown is omitted here for detailed description.

[0058] The controller 90 controls the operation of the displacement sensor 10 (specifically, the radiating part 20 and the light receiving part 30). Furthermore, the controller 90 controls, for example, a drive source for moving the workpiece W in the displacement direction (vertical direction), and can move the workpiece W. The controller 90 includes a memory 92 and a control unit 94.

[0059] The memory 92 includes, for example, read-only memory (ROM) and random access memory (RAM). The memory 92 stores programs and various types of data that can be executed by the control unit 94. For example, the memory 92 stores the results detected by the displacement sensor 10.

[0060] The control unit 94 is, for example, a central processing unit (CPU). The control unit 94 controls the operation of the displacement sensor 10 by executing a program stored in the memory 92.

[0061] The control unit 94 controls the light radiation from the light source 22 of the radiating unit 20 to the workpiece W. Furthermore, the control unit 94 acquires the output of the light receiving unit 30 and calculates the contour of the workpiece W. In other words, the control unit 94 functions as a calculation unit for calculating the contour of the workpiece W based on the output of the light receiving unit 30 of the displacement sensor 10.

[0062] (Effect in the first embodiment)

[0063] In the displacement sensor 10 according to the first embodiment, the light receiving part 30 and the stripe generating part 40 are arranged such that they are parallel to the displacement direction of the workpiece W.

[0064] Therefore, even when the workpiece W is displaced, a) the distance u between the radiation point P on the workpiece W and the stripe generating part 40 and b) the distance v between the stripe generating part 40 and the light receiving part 30 will not change, and thus the period of the stripes generated on the surface 32 of the light receiving part 30 will not change. Therefore, since there is no deviation between the period of the stripes and the period of the detection element on the light receiving surface 32, the stripes can be accurately detected even when the workpiece W is displaced.

[0065] <Second Embodiment>

[0066] Reference Figure 5 The configuration of the displacement sensor 10 according to the second embodiment is described.

[0067] The difference is that in the second embodiment, the generating device is a stepped portion, while in the first embodiment, the generating device for the stripe generating portion 40 is the aperture 44 of the diffraction grating 42.

[0068] Figure 5 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the second embodiment. For example... Figure 5 As shown, the displacement sensor 10 according to the second embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 and the light receiving section 30 in the second embodiment is the same as that in the first embodiment, so their description is omitted below.

[0069] The stripe generating section 40 includes a substrate 50 with multiple steps 52, instead of a diffraction grating 42 with holes. The substrate 50 is transparent and transmits reflected light from the workpiece W. The steps 52 here are protruding portions of the substrate 50. The substrate 50 is configured such that it is parallel to the displacement direction of the workpiece W (in other words, the radiating plane 26). The stripe generating section 40 generates stripes with a periodic d on the light receiving surface 32. D Stripes.

[0070] It should be noted that, for ease of interpretation, the period of the stripes when workpiece W is located at position X1 is... Figure 5 As shown in the figure, the period of the stripes does not change even when the workpiece W is displaced.

[0071] By providing a substrate 50, the stripe generating unit 40 generates stripes on the light receiving surface 32 using reflected light transmitted through the step 52. During this process, a phase difference occurs between the reflected light transmitted through the step 52 of the substrate 50 and the reflected light transmitted through the portion other than the step 52, resulting in interference in the reflected light. When the wavelength of the light radiated by the radiating unit 20 is λ, the thickness of the step 52 should be set such that the phase difference of the reflected light becomes λ / 2.

[0072] In the second embodiment, the substrate 50 with the step 52 is placed parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced, the period of the stripes generated on the light-receiving surface 32 does not change, as in the first embodiment. As a result, there is no deviation between the period of the stripes on the light-receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0073] <Third Embodiment>

[0074] Reference Figure 6 The configuration of the displacement sensor 10 according to the third embodiment is described.

[0075] In the first embodiment, a) the distance u between the stripe generating part 40 and the radiation point P and b) the distance v between the stripe generating part 40 and the light receiving surface 32 have different lengths, while in the third embodiment, these two distances have the same length.

[0076] Figure 6 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the third embodiment. For example... Figure 6 As shown, the displacement sensor 10 according to the third embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 and the light receiving section 30 according to the third embodiment is the same as that of the first embodiment.

[0077] According to the third embodiment, the fringe generating unit 40 includes a plurality of generating devices arranged at predetermined intervals. For example, the fringe generating unit 40 includes a plurality of holes 46 arranged at predetermined intervals in the diffraction grating 42 as generating devices. Here, it is assumed that the plurality of holes 46 are arranged with a predetermined period g.

[0078] The stripe generating section 40 is located at the midpoint between the radiation point P of the radiation section 20 and the light receiving surface 32. That is, the distance u between the stripe generating section 40 and the radiation point P has the same length as the distance v between the stripe generating section 40 and the light receiving surface 32.

[0079] As described above, when multiple apertures 46 are arranged with a predetermined period g and the distances u and v are of the same length, stripes with a period g are generated on the light-receiving surface 32. That is, the period of the apertures 46 and the period g of the stripes have the same size. Therefore, by making the spacing between the apertures 46 smaller, fine stripes can be generated on the light-receiving surface 32.

[0080] In the third embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period g of the stripes does not change. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W moves.

[0081] <Fourth Embodiment>

[0082] Reference Figure 7 The configuration of the displacement sensor 10 according to the fourth embodiment is described.

[0083] The difference lies in that, in the first embodiment, the generating device for the stripe generating unit 40 is the aperture 44 of the diffraction grating 42, while in the fourth embodiment, the generating device is an image forming element. An image forming element is an element that has the function of acquiring an image using an optical system.

[0084] Figure 7 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the fourth embodiment. For example... Figure 7 As shown, the displacement sensor 10 according to the fourth embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 and the light receiving section 30 according to the fourth embodiment is the same as that of the first embodiment.

[0085] The stripe generation unit 40 includes a plurality of image forming elements 55 arranged adjacent to each other as a generation device. Specifically, as shown in the figure... Figure 7 As shown, the three image forming elements 55 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced, stripes can be generated on the light receiving surface 32 by the three image forming elements 55. In the above description, three image forming elements 55 are provided, but the invention is not limited thereto, and four or more image forming elements 55 may be provided.

[0086] For example, multiple image forming elements 55 are focusing lenses. When a focusing lens is used, the power of the light received by the light receiving surface 32 is high. It should be noted that in the above description, the image forming element 55 is a focusing lens, but the invention is not limited thereto. For example, the image forming element 55 can be another lens, such as a Fresnel lens, or a diffractive optical element, such as a Fresnel zone plate. Therefore, image forming elements 55 with a small thickness can be provided.

[0087] In the fourth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period of the stripes does not change. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0088] <Fifth Embodiment>

[0089] Reference Figure 8 The configuration of the displacement sensor 10 according to the fifth embodiment is described.

[0090] The difference lies in that, in the first embodiment, the stripe generating unit 40 includes a single diffraction grating 42, while in the fifth embodiment, the stripe generating unit 40 includes multiple diffraction gratings.

[0091] Figure 8 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the fifth embodiment. For example... Figure 8 As shown, the displacement sensor 10 according to the fifth embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 according to the fifth embodiment is the same as that of the first embodiment.

[0092] According to the fifth embodiment, the fringe generating section 40 includes a plurality of diffraction gratings, wherein a plurality of generating devices are formed. For example, the fringe generating section 40 includes a first diffraction grating 60, a second diffraction grating 62, and a third diffraction grating 64. The first diffraction grating 60, the second diffraction grating 62, and the third diffraction grating 64 are arranged in a row such that they are parallel to the displacement direction of the workpiece W.

[0093] exist Figure 8 The diagram is shown in a simplified form, but the first diffraction grating 60, the second diffraction grating 62, and the third diffraction grating 64 include a plurality of apertures similar to those of the diffraction grating 42 described above. The first diffraction grating 60 includes apertures arranged in a first period, the second diffraction grating 62 includes apertures arranged in a second period, and the third diffraction grating 64 includes apertures arranged in a third period. The lengths of the first, second, and third periods are different from each other. That is, the spacing between the apertures of the first diffraction grating 60, the second diffraction grating 62, and the third diffraction grating 64 is different from each other.

[0094] The light receiving section 30 includes multiple light receiving surfaces corresponding to the multiple diffraction gratings of the stripe generating section 40. For example, the light receiving section 30 includes a first light receiving surface 36, a second light receiving surface 37, and a third light receiving surface 38. The first light receiving surface 36, the second light receiving surface 37, and the third light receiving surface 38 are arranged in a row such that they are parallel to the displacement direction of the workpiece W.

[0095] A first diffraction grating 60 generates fringes on a first light-receiving surface 36, a second diffraction grating 62 generates fringes on a second light-receiving surface 37, and a third diffraction grating 64 generates fringes on a third light-receiving surface 38. The periods of the fringes generated on the first light-receiving surface 36, the second light-receiving surface 37, and the third light-receiving surface 38 are different from each other. This allows the first light-receiving surface 36, the second light-receiving surface 37, and the third light-receiving surface 38 to output signals of different wavelengths. By outputting signals of different wavelengths, the absolute position of the workpiece W can be obtained.

[0096] In the fifth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period of the stripes does not change. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0097] <Sixth Embodiment>

[0098] Reference Figure 9 The configuration of the displacement sensor 10 according to the sixth embodiment is described.

[0099] The difference lies in that, in the first embodiment, the light receiving unit 30 includes an image sensor, while in the sixth embodiment, the light receiving unit 30 includes a photodiode array in which multiple photodiodes are arranged.

[0100] Figure 9 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the sixth embodiment. For example... Figure 9 As shown, the displacement sensor 10 according to the sixth embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 and the stripe generating section 40 according to the sixth embodiment is the same as that of the first embodiment.

[0101] The light receiving unit 30 according to the sixth embodiment includes a photodiode array 34 in which a plurality of photodiodes 35a to 35d are arranged. The photodiodes 35a to 35d are optical detectors for detecting light. The photodiodes 35a to 35d are arranged in a row such that they are parallel to the radiation plane 26. Furthermore, the photodiodes 35a to 35d are arranged alternately.

[0102] The photodiodes 35a to 35d output current as an analog output. Therefore, the light receiver 30 responds quickly, enabling rapid detection. Furthermore, when photodiodes 35a to 35d are used in the light receiver 30, the generated heat can be suppressed compared to using an image sensor.

[0103] The light receiving unit 30 can determine the displacement of the stripes generated due to the displacement of the workpiece W by determining the difference (displacement) between the outputs of photodiodes 35a and 35c and the difference (displacement) between the outputs of photodiodes 35b and 35d. It should be noted that the displacement increases as the above differences increase.

[0104] In the sixth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period of the stripes does not change. As a result, since there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, the stripes can be accurately detected even when the workpiece W is displaced.

[0105] <Seventh Embodiment>

[0106] Reference Figure 10 The configuration of the displacement sensor 10 according to the seventh embodiment is described.

[0107] The difference lies in that, in the first embodiment, the plurality of generating devices (the apertures of the diffraction grating 42) of the stripe generating section 40 are arranged at a predetermined period, while in the seventh embodiment, the plurality of generating devices are arranged such that the interval between adjacent generating devices is random.

[0108] Figure 10 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the seventh embodiment. For example... Figure 10 As shown, the displacement sensor 10 according to the seventh embodiment includes a radiating section 20, a light receiving section 30, and a stripe generating section 40. The configuration of the radiating section 20 and the light receiving section 30 according to the seventh embodiment is the same as that of the first embodiment.

[0109] According to the seventh embodiment, the fringe generation unit 40 includes a diffraction grating 42 arranged such that the spacing between the plurality of apertures 48 is random. For example, a pseudo-random code called a maximum-length sequence (M-sequence) code can be applied to the random arrangement of the plurality of apertures 48. The M-sequence code is composed of a) an n-stage shift register and b) the longest sequence among the sequences calculated by addition.

[0110] For each position of workpiece W, the three light-receiving positions of the receiving stripes on the light-receiving surface 32 are different and do not overlap.

[0111] Figure 4 The controller 90 of the contour measuring device 1 specifies the displacement of the workpiece W by matching a) the three light receiving positions of the stripes output by the light receiving unit 30 with b) the pattern of light receiving positions pre-stored in the memory 92.

[0112] The memory 92 stores multiple patterns indicating the light-receiving positions (specifically, the three light-receiving positions of the receiving stripe) on the light-receiving surface 32 of the receiving stripe. The multiple stored patterns stored in the memory 92 are pre-measured and include three light-receiving positions that do not overlap with each other.

[0113] The control unit 94 acquires three light receiving positions of the stripes received from the light receiving unit 30. The control unit 94 determines which of the multiple stored patterns stored in the memory 92 matches the acquired three light receiving positions. The control unit 94 selects the stored pattern with the highest matching degree and detects displacement based on the selected stored pattern.

[0114] In the seventh embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period of the stripes does not change. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0115] Furthermore, in the seventh embodiment, since the multiple image forming apparatuses are randomly arranged such that the light receiving positions of the receiving stripes on the light receiving surface 32 do not overlap, the displacement of the workpiece W is precisely specified.

[0116] It should be noted that when Figure 10 When the workpiece W shown has a transparent body, even if the transparent body has multiple measuring points on it, the above configuration can separate the multiple measuring points on the transparent body. For example, when Figure 10 When position X1 is the back surface of the transparent object and position X2 is the front surface of the transparent object, the front and back surfaces of the transparent object can be specified separately.

[0117] <Eighth Embodiment>

[0118] Reference Figure 11 The configuration of the displacement sensor 10 according to the eighth embodiment is described.

[0119] Figure 11 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the eighth embodiment. For example... Figure 11 As shown, in addition to the radiating part 20, the light receiving part 30 and the stripe generating part 40, the displacement sensor 10 also includes a reflective member 70.

[0120] The reflective member 70 is used to reflect reflected light from the workpiece W toward the stripe generating section 40. The reflective member 70 is, for example, a mirror, and is arranged such that the direction of its surface intersects the displacement direction of the workpiece W. In the displacement direction of the workpiece W, the reflective member 70 is disposed near the radiating section 20.

[0121] According to the first embodiment, the stripe generating section 40 and the light receiving section 30 are arranged parallel to the displacement direction of the workpiece W, while according to the eighth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that their directions intersect with the displacement direction of the workpiece W. On the other hand, according to the eighth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the virtual image of the workpiece W's displacement direction.

[0122] Figure 11 A virtual image 75 of the displacement direction of workpiece W is shown. Virtual image 75 is about... Figure 11 A virtual image is generated at a position symmetrical to the longitudinal line of the reflecting member 70 and the displacement direction (vertical direction) of the workpiece W. The stripe generating section 40 and the light receiving section 30 are each arranged such that they are parallel to the virtual image 75. Furthermore, the stripe generating section 40 and the light receiving section 30 are positioned in the vertical direction at substantially the same position as the reflecting member 70.

[0123] In the eighth embodiment, since the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the virtual image 75 in the displacement direction of the workpiece W, the period of the stripes will not change even when the workpiece W is displaced in the displacement direction. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0124] Furthermore, in the eighth embodiment, the reflective member 70 makes it easier to position the displacement sensor 10 away from the workpiece W. That is, in the displacement direction of the workpiece W, in the first embodiment, the stripe generating part 40 and the light receiving part 30 are located near the workpiece W, while in the eighth embodiment, the stripe generating part 40, the light receiving part 30, and the reflective member 70 are positioned away from the workpiece W.

[0125] <Ninth Embodiment>

[0126] Reference Figure 12 The configuration of the displacement sensor 10 according to the ninth embodiment is described.

[0127] The difference lies in that, according to the first embodiment, the radiating section 20 illuminates the workpiece W with a point light, while in the ninth embodiment, the radiating section 20 illuminates the workpiece W with a line beam of light, which is a linear light source. As an example, the radiating section 20 according to the ninth embodiment includes a light source 22 (see...) Figure 1 A cylindrical lens that converts the emitted laser beam into a line beam.

[0128] Figure 12 This is a schematic diagram used to explain the configuration of the displacement sensor 10 according to the ninth embodiment. Figure 12 In the diagram, the thicker line represents a line beam. Here, the line beam illuminates the workpiece W, making the width of the line beam wider than the width of the workpiece W. The stripe generating unit 40 receives reflected light (hereinafter, the reflected line beam) from the workpiece W and generates stripes on the light receiving surface 32 of the light receiving unit 30. The stripe generating unit 40 includes, for example, the diffraction grating 42 and the step 52 described above as means for generating stripes.

[0129] The light-receiving surface 32 of the light-receiving unit 30 can detect the position of the stripes generated by the stripe generating unit 40 in two orthogonal axis directions. The light-receiving surface 32 is provided with, for example, a region sensor capable of detecting the position in two orthogonal axis directions.

[0130] Similarly, in the ninth embodiment, the stripe generating section 40 and the light receiving section 30 are arranged such that they are parallel to the displacement direction of the workpiece W. Therefore, even when the workpiece W is displaced in the displacement direction, the period of the stripes does not change. As a result, there is no deviation between the period of the stripes on the light receiving surface 32 and the period of the detection element, so the stripes can be accurately detected even when the workpiece W is displaced.

[0131] Furthermore, in the ninth embodiment, the displacement of the entire workpiece W can be detected immediately by irradiating the workpiece W with a line beam.

[0132] This invention is explained based on exemplary embodiments. The technical scope of this invention is not limited to the scope explained in the above embodiments, and various changes and modifications can be made within the scope of this invention. For example, all or part of the device can be configured to be functionally or physically distributed and integrated in any unit. Furthermore, new exemplary embodiments generated by any combination thereof are included in the exemplary embodiments of this invention. The effects of the new embodiments resulting from the combinations also have the effects of the original embodiments.

[0133] List of reference numerals

[0134] 1. Contour measuring equipment

[0135] 10 Displacement Sensors

[0136] 20 Radiation Department

[0137] 30 Optical Receiver

[0138] 32 Light receiving surface

[0139] 34 photodiode array

[0140] 35A-35D photodiode

[0141] 40 stripe generating section

[0142] 42 Diffraction grating

[0143] 52 steps

[0144] 55 Image forming elements

[0145] 70 Reflective component

[0146] 75 virtual image

[0147] 94 Control Department

[0148] W workpiece

Claims

1. A displacement sensor, comprising: An irradiation section that irradiates a workpiece that can be moved in a predetermined displacement direction with light; A light receiving unit that receives reflected light, which is generated when light irradiated by an irradiating unit is reflected on a workpiece; as well as A stripe generating section includes a generating structure for generating stripes on the light-receiving surface of a light-receiving section when the light-receiving section receives reflected light from a workpiece, wherein... The displacement direction is along the optical axis of the light irradiating the workpiece from the irradiation point, and The fringe generating section and the light receiving section are arranged such that the fringe generating section and the light receiving section are parallel to the displacement direction, or parallel to the virtual image of the displacement direction.

2. The displacement sensor according to claim 1, wherein, The stripe generating section includes a diffraction grating having a plurality of holes as the generating structure, and the stripe generating section generates stripes on the light receiving surface using reflected light passing through the holes.

3. The displacement sensor according to claim 1, wherein, The stripe generating section includes a substrate on which a plurality of steps are formed as the generating structure, and the stripe generating section generates stripes on the light receiving surface using reflected light transmitted through the steps.

4. The displacement sensor according to claim 1, wherein, The stripe generating section includes a plurality of generating structures arranged at predetermined intervals, and The distance between the stripe generating part and the irradiation plane of the irradiation part has the same length as the distance between the stripe generating part and the light receiving surface.

5. The displacement sensor according to claim 1, wherein, The fringe generating section includes a diffraction grating having a plurality of holes serving as the generating structure. The plurality of holes are arranged at predetermined intervals, and The distance between the stripe generating part and the irradiation plane of the irradiation part has the same length as the distance between the stripe generating part and the light receiving surface.

6. The displacement sensor according to claim 1, wherein, The stripe generating section includes a plurality of image forming elements as the generating structure, the image forming elements being arranged in a row adjacent to each other along the displacement direction.

7. The displacement sensor according to claim 1, wherein, The fringe generating section includes a plurality of diffraction gratings arranged parallel to the displacement direction or the virtual image, and has a plurality of holes formed therein as the generating structure. The spacing between the apertures in the diffraction grating is different from each other.

8. The displacement sensor according to claim 1, wherein, The light receiving unit includes a photodiode array, in which multiple photodiodes for detecting the reflected light are arranged.

9. The displacement sensor according to claim 1, wherein, The generating structures are arranged such that the interval between adjacent generating structures along the displacement direction is random.

10. The displacement sensor according to claim 9, wherein, The fringe generating section includes a diffraction grating, in which a plurality of holes are formed as the generating structure, and The plurality of holes are arranged such that the interval between adjacent holes is random.

11. The displacement sensor according to claim 1, further comprising: A reflective member that reflects reflected light from the workpiece toward the stripe generating portion, wherein, The stripe generating portion and the light receiving portion are arranged such that when viewed from the reflective member, the stripe generating portion and the light receiving portion are parallel to the virtual image of the displacement direction.

12. The displacement sensor according to claim 1, wherein, The irradiation section irradiates the workpiece with linear light, and The stripe generating unit generates stripes on the light receiving surface for detecting positions on two orthogonal axes.

13. A profile measuring device, comprising: A displacement sensor includes: a) an illumination section for illuminating a workpiece displaceable in a predetermined displacement direction with light; b) a light receiving section for receiving reflected light, the reflected light being generated when light irradiated from the illumination section is reflected onto the workpiece; and c) a stripe generating section including a generating structure for generating stripes on the light-receiving surface of the light receiving section when the light receiving section receives reflected light from the workpiece; and The calculation unit calculates the contour of the workpiece based on the output of the light receiving unit, wherein... The displacement direction is along the optical axis of the light irradiating the workpiece from the irradiation point, and The fringe generating section and the light receiving section are arranged such that the fringe generating section and the light receiving section are parallel to the displacement direction, or parallel to the virtual image in the displacement direction.

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