Three-dimensional measuring device

Abstract

The three-dimensional measuring device (101) includes: one or more light source units (102) that irradiate a measuring light (105) with a predetermined pattern onto a measured object (SA); one or more camera units (103) that capture images of the measured object (SA) irradiated with the measuring light (105); and a measuring unit (104) that measures the three-dimensional shape of the measured object (SA) based on the imaging results of the camera units (103). The light source units (102) are composed of an M-point oscillating S-iPMSEL (1).

Description

[0001] This application was filed on [date]. February 18, 2021 Application number is 202110187715.2 The invention is named 3D measurement Measuring device A divisional application of the patent application. Technical Field

[0002] This invention relates to a three-dimensional measuring device. Background Technology

[0003] As an existing method for three-dimensional measurement, there is, for example, the method described in U.S. Patent Application Publication No. 2008 / 0240502 (Patent Document 1). In the method of Patent Document 1, a random dot pattern is projected onto the object to be measured, and two cameras are used to capture images of the dot pattern at the same location. Then, based on the parallax of the two dot patterns, a three-dimensional measurement of the object is performed according to the principle of triangulation.

[0004] Furthermore, the method described in, for example, Japanese Patent Application Publication No. 2011-242178 (Patent Document 2) is a measurement method using the phase-shifting method. In this method, a reference plate having a reference surface with a projected grid pattern is prepared, and the reference plate is moved parallel to the normal direction using a worktable. Images of the grid pattern projected onto the reference surface and images of the grid pattern projected onto the object being measured are captured, and the spatial coordinates of the object being measured are calculated using a table that corresponds the phase of the grid pattern to its spatial coordinates. Summary of the Invention

[0005] In the method of Patent Document 1, a projector is used as the light source, while in the method of Patent Document 2, an LED array is used. Therefore, there are issues such as the need for a relatively large 3D measuring device. As a camera device, an ultra-small camera, for example, less than 1 mm square, has been developed. To achieve overall miniaturization of the 3D measuring device, it is important to miniaturize the light source. It is believed that as long as the overall 3D measuring device can be miniaturized, it can be applied to applications such as oral examinations, endoscopy, inspection of narrow parts such as the interior of tubes or gaps in walls, inspection of furniture or devices from under the floor, or the construction of handheld 3D measuring devices. Furthermore, when applying a light source to a 3D measuring device, from the viewpoint of improving measurement accuracy, a light source that suppresses noise or distortion of the output light is preferred.

[0006] This invention was created to solve the above-mentioned technical problems. Its purpose is to provide a three-dimensional measuring device that expands its application range and improves its measurement accuracy through miniaturization.

[0007] A three-dimensional measuring apparatus according to one aspect of the present invention comprises: one or more light source units that irradiate a measuring light having a predetermined pattern onto a measured object; one or more camera units that capture images of the measured object irradiated with the measuring light; and a measuring unit that measures the three-dimensional shape of the measured object based on the imaging results of the camera units, wherein the light source units are composed of an M-point oscillating S-iPMSEL.

[0008] In this 3D measurement device, the light source is composed of an M-point oscillating S-iPMSEL. The S-iPMSEL has a base layer and a phase modulation layer with multiple regions of different refractive indices, each having a different refractive index than the base layer. The centroid position of each region deviates from the position of a grid point in an imaginary square lattice based on the output light image. The S-iPMSEL is constructed to a size similar to, for example, a pinhead, and can output a two-dimensional pattern light image along a direction perpendicular to the main surface of the substrate on which the phase modulation layer is located, or in a direction inclined relative to that main surface. Therefore, by using an S-iPMSEL as the light source, the overall 3D measurement device can be miniaturized, expanding its application range. Furthermore, by using an M-point oscillating S-iPMSEL, the output of zero-order light (undemonicated diffracted wave components) that differs from the desired two-dimensional pattern light image can be eliminated. Thus, measurement light with a pattern free from noise or distortion caused by zero-order light can be irradiated onto the object being measured, improving measurement accuracy.

[0009] Alternatively, the 3D measuring device may include a single light source and multiple camera units. The prescribed pattern for measuring the light is a periodic pattern composed of any one of dot patterns, bar patterns, and grid patterns. The measuring unit measures the 3D shape of the object being measured based on an active stereo method using the periodic pattern. In this case, 3D measurement using images with low texture and 3D measurement in dark areas can be performed.

[0010] The three-dimensional measuring device includes a single light source unit and multiple camera units. The prescribed pattern of the measuring light is a random dot pattern, and the measuring units measure the three-dimensional shape of the object being measured based on an active stereo method using the random dot pattern. In this case, by using a random dot pattern instead of a periodic dot pattern, misidentification when capturing the same point of the dot pattern through different camera units can be suppressed.

[0011] Alternatively, the 3D measurement device may include a single light source and multiple camera units. The prescribed pattern of the measurement light is a pattern with uniform density, and the measurement units measure the 3D shape of the object being measured based on an active stereo method using a pattern with uniform density. Since the emitted light from the S-iPMSEL is laser light, speckle patterns may appear in the scattered light. Therefore, even when using a pattern with uniform density, a random dot pattern will form in the measurement light pattern. By using this random dot pattern, misidentification when capturing the same point of the dot pattern through different camera units can be suppressed.

[0012] Alternatively, the 3D measuring device may include multiple light sources and a single camera unit. The prescribed pattern for the measuring light is a Gray code pattern, and the measuring unit measures the 3D shape of the object being measured based on triangulation using the Gray code pattern. The number of Gray code patterns needs to be small relative to the number of pixels in the camera unit; therefore, the illumination of the measuring light with the Gray code pattern can be achieved with only a few light sources. When using Gray code, the Hamming distance between adjacent pixels is 1, and even if dislocations occur during bit flow recovery, the error converges to 1. That is, in Gray code, a noisy symbol can be obtained.

[0013] Alternatively, the three-dimensional measuring device may include multiple light sources and a single camera unit. The prescribed pattern of the measuring light is a sinusoidal bar pattern, and the measuring unit measures the three-dimensional shape of the object being measured based on a phase-shifting method using the sinusoidal bar pattern. In this case, by performing height conversion on the measured phase, the height of the object being measured can be measured at intervals smaller than the pitch of the sinusoidal bar pattern.

[0014] Alternatively, multiple light sources can output sinusoidal bar patterns with different periods. In the phase-shifting method, discontinuities at a phase of 2π pose a technical challenge. In contrast, by using sinusoidal bar patterns with different periods, these discontinuities at 2π can be mitigated, enabling high-precision three-dimensional measurements with a limited number of patterns.

[0015] Alternatively, the 3D measuring device may include multiple light sources and a single camera unit. The prescribed pattern for measuring the light is a sinusoidal bar pattern, and the measuring unit measures the 3D shape of the object being measured based on the sampling moiré method using the sinusoidal bar pattern. In this case, high-precision 3D measurement can be achieved with fewer patterns.

[0016] Alternatively, the 3D measuring device may include multiple light sources and a single camera unit. The prescribed pattern for measuring the light is an overlapping pattern, which combines a sinusoidal bar pattern and a random dot pattern. The measuring unit measures the 3D shape of the object being measured based on a phase-shifting method using the overlapping pattern. In the phase-shifting method, discontinuities at a phase of 2π become a technical problem. In contrast, by using a random dot pattern, the discontinuities at a phase of 2π can be improved, enabling high-precision 3D measurement with a small number of patterns.

[0017] Alternatively, the 3D measurement device may include multiple light sources and a single camera unit. The prescribed pattern for measuring the light includes sinusoidal bar patterns and Gray code patterns. The measurement unit measures the 3D shape of the object being measured based on the phase-shifting method using sinusoidal bar patterns and the triangulation method using Gray code patterns. In the phase-shifting method, the discontinuity at a phase of 2π becomes a technical problem. In contrast, by using Gray code, the discontinuity at a phase of 2π can be improved, enabling high-precision 3D measurement with a few patterns.

[0018] Alternatively, the 3D measuring device may include multiple light sources and multiple cameras. The prescribed pattern for measuring light is a sinusoidal bar pattern. The measuring units measure the 3D shape of the object being measured based on the phase-shifting method and the active stereo method using the sinusoidal bar pattern. In this case, by converting the measured phase to height, the height of the object can be measured at intervals smaller than the pitch of the sinusoidal bar pattern. Furthermore, in the phase-shifting method, discontinuities at a phase of 2π become a technical problem. In contrast, by combining the active stereo method using multiple cameras, the discontinuities at a phase of 2π can be improved, enabling high-precision 3D measurement with a few patterns.

[0019] Alternatively, the light source and camera unit can be disposed on the surface of the three-dimensional object. In this case, the three-dimensional object with the light source and camera unit disposed thereon can be configured as a probe of a three-dimensional measuring device. By using the three-dimensional object, the light source and camera unit can be oriented in different directions, thus allowing for three-dimensional shape measurement of the object at a large solid angle. Furthermore, it is easily applicable to applications such as oral examinations, endoscopy, inspection of narrow parts such as the interior of tubes or gaps in walls, inspection of furniture or devices from under the floor, or the construction of handheld three-dimensional measuring devices. Attached Figure Description

[0020] Figure 1 This is a partial three-dimensional sectional view representing the structure of S-iPMSEL.

[0021] Figure 2 This is a cross-sectional view showing the stacked structure of S-iPMSEL.

[0022] Figure 3 This is a top view of the phase modulation layer.

[0023] Figure 4 It is a diagram that expands the representation of the region R that constitutes the unit.

[0024] Figure 5 This is a top view showing an example of applying a roughly periodic refractive index structure in a specific region of the phase modulation layer.

[0025] Figure 6This is a diagram illustrating the relationship between the optical image obtained by imaging the output beam pattern of the S-iPMSEL and the rotation angle distribution on the phase modulation layer.

[0026] Figure 7 It is a diagram illustrating the coordinate transformation from spherical coordinates to coordinates in an orthogonal XYZ coordinate system.

[0027] Figure 8 This is a top view of the reciprocal lattice space of the phase modulation layer of the S-iPMSEL oscillating about point M.

[0028] Figure 9 This is a conceptual diagram illustrating the state of the in-plane wavenumber vector plus the diffraction vector.

[0029] Figure 10 It is a diagram used to schematically illustrate the surrounding structure of light.

[0030] Figure 11 This is a diagram that conceptually represents an example of the rotation angle distribution φ2(x,y).

[0031] Figure 12 It is a conceptual diagram used to illustrate the state of removing wavenumber diffusion from the in-plane wavenumber vector of the direction and adding the diffraction vector.

[0032] Figure 13 This is a top view of the phase modulation layer in the modified example.

[0033] Figure 14 This is a diagram showing the positional relationship of different refractive index regions on the phase modulation layer of the modified example.

[0034] Figure 15 This is a schematic diagram showing the structure of the three-dimensional measuring device according to the first embodiment.

[0035] Figure 16 This is a diagram illustrating an example of the periodic pattern used in the first embodiment.

[0036] Figure 17 This is an example of a far-field image representing a periodic pattern.

[0037] Figure 18 This is a diagram illustrating an example of the random dot pattern used in the first embodiment.

[0038] Figure 19 This is a diagram illustrating an example of a pattern with uniform density used in the first embodiment.

[0039] Figure 20 This is a diagram representing an example of an FFP with a uniform density pattern.

[0040] Figure 21This is a schematic diagram showing the structure of the three-dimensional measuring device according to the second embodiment.

[0041] Figure 22 This is a diagram illustrating an example of the Gray code pattern used in the second embodiment.

[0042] Figure 23 This is a diagram illustrating an example of a sinusoidal bar pattern used in the second embodiment.

[0043] Figure 24 This is a diagram illustrating an example of a sinusoidal matrix pattern used in the second embodiment.

[0044] Figure 25 This is a diagram showing the improved case of discontinuities at phase 2π.

[0045] Figure 26 This is a diagram illustrating an example of the moiré pattern used in the second embodiment.

[0046] Figure 27 This is a diagram illustrating an example of the overlapping pattern used in the second embodiment.

[0047] Figure 28 This is a diagram illustrating another example of the overlapping pattern used in the second embodiment.

[0048] Figure 29 This is a schematic diagram showing the structure of the three-dimensional measuring device according to the third embodiment.

[0049] Figure 30 This is a schematic perspective view showing an example of the configuration of the light source and the camera unit.

[0050] Figure 31 This is a schematic perspective view showing another configuration example of the light source and camera unit.

[0051] Figure 32 It is a three-dimensional diagram showing an example of the formation of a sinusoidal bar pattern.

[0052] Figure 33 This is a schematic diagram representing an example of a laser with a multi-dot pattern and a bar pattern using the laser.

[0053] Figure 34 This is a schematic diagram representing a laser with a multi-dot pattern and another example of a bar pattern using the laser.

[0054] Figure 35 This is a schematic cross-sectional view showing an example of the structure of a metal lens. Detailed Implementation

[0055] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of a three-dimensional measuring device according to one aspect of the present invention will be described in detail.

[0056] The three-dimensional measuring device 101 of this embodiment is configured to include one or more light source units 102 that irradiate a measuring light 105 with a predetermined pattern onto a measured object SA, one or more imaging units 103 that capture images of the measured object SA irradiated with the measuring light 105, and a measuring unit 104 that measures the three-dimensional shape of the measured object SA based on the imaging results of the imaging units 103 (see reference). Figure 15 (etc.). In addition, the light source unit 102 is composed of an M-point oscillating S-iPMSEL (Static-integrable PhaseModulating Surface Emitting Laser) 1.

[0057] In the three-dimensional measuring device 101, by using an S-iPMSEL1 with a tip-like size to form the light source unit 102, the overall device can be miniaturized, expanding its application range. Furthermore, by using an M-point oscillating S-iPMSEL1 in the three-dimensional measuring device 101, the output of zero-order light (undial diffracted wave components) that differs from the desired two-dimensional pattern can be eliminated. Therefore, measurement light 105 with a pattern free from noise or distortion caused by zero-order light can be irradiated onto the measured object SA, improving measurement accuracy.

[0058] [S-iPMSEL oscillation at point M]

[0059] First, the S-iPMSEL1 oscillation at point M will be explained. Figure 1 This is a partial three-dimensional sectional view showing the structure of SiPMSEL. Figure 2 This is a cross-sectional view showing the stacked structure of S-iPMSEL. Figure 1 In this context, an orthogonal XYZ coordinate system is defined with the axis extending along the thickness direction of S-iPMSEL1 from the center of S-iPMSEL1 as the Z-axis.

[0060] S-iPMSEL1 is a laser source that forms a standing wave in the XY plane and outputs a phase-controlled plane wave along the Z-axis. S-iPMSEL1 outputs a light image of arbitrary two-dimensional shape in a direction perpendicular to the main surface 10a of the semiconductor substrate 10 (i.e., the Z-axis direction), or in a direction inclined relative to the main surface 10a, or including both directions.

[0061] like Figure 1 and Figure 2As shown, the S-iPMSEL1 includes an active layer 12 serving as a light-emitting portion disposed on a semiconductor substrate 10, a pair of cladding layers 11 and 13 sandwiching the active layer 12, and a contact layer 14 disposed on the cladding layer 13. The semiconductor substrate 10, cladding layers 11 and 13, and contact layer 14 are made of compound semiconductors such as GaAs-based semiconductors, InP-based semiconductors, or nitride-based semiconductors. The energy band gap of the cladding layer 11 and the energy band gap of the cladding layer 13 are larger than the energy band gap of the active layer 12. The thickness direction of the semiconductor substrate 10 and each layer 11-14 is aligned with the Z-axis direction.

[0062] The S-iPMSEL1 also includes a phase modulation layer 15 optically coupled to the active layer 12. In this embodiment, the phase modulation layer 15 is disposed between the active layer 12 and the cladding layer 13. The thickness direction of the phase modulation layer 15 is aligned with the Z-axis direction. The phase modulation layer 15 may also be disposed between the cladding layer 11 and the active layer 12. Depending on the requirements, a light guide layer may also be disposed between at least one of the active layer 12 and the cladding layer 13, and between the active layer 12 and the cladding layer 11. The light guide layer may include a carrier barrier layer for efficiently confining carriers to the active layer 12.

[0063] The phase modulation layer 15 is configured to include a base layer 15a made of a first refractive index medium and multiple regions 15b with different refractive indexes existing within the base layer 15a, both made of a second refractive index medium with a different refractive index than the first refractive index medium. The multiple regions 15b with different refractive indexes have a generally periodic structure. Assuming the equivalent refractive index of the mode is n, the wavelength λ0 (=(√2)a×n, where a is the lattice spacing) selected by the phase modulation layer 15 is within the emission wavelength range of the active layer 12. The phase modulation layer 15 can select a band-end wavelength near wavelength λ0 in the emission wavelength range of the active layer 12 and output it to the outside. Laser incident on the phase modulation layer 15 forms a predetermined pattern within the phase modulation layer 15 corresponding to the configuration of the different refractive index regions 15b, and as a laser beam with a desired pattern, is emitted from the surface of the S-iPMSEL1 to the outside.

[0064] The S-iPMSEL1 also includes an electrode 16 disposed on the contact layer 14 and an electrode 17 disposed on the back surface 10b of the semiconductor substrate 10. Electrode 16 is in ohmic contact with the contact layer 14, and electrode 17 is in ohmic contact with the semiconductor substrate 10. Electrode 17 has an opening 17a. Electrode 16 is disposed in the central region of the contact layer 14. The portion of the contact layer 14 excluding electrode 16 is protected by a protective film 18 (see reference). Figure 2The contact layer 14, which is not in contact with the electrode 16, can also be removed due to the limitation of the current range. The portion of the back surface 10b of the semiconductor substrate 10, excluding the electrode 17, including the opening 17a, is covered by the anti-reflective film 19. The anti-reflective film 19 located outside the opening 17a can also be removed.

[0065] In the S-iPMSEL1, if a driving current is supplied between electrodes 16 and 17, electrons and holes recombine within the active layer 12, causing the active layer 12 to emit light. The electrons, holes, and light generated in the active layer 12 that contribute to this luminescence are efficiently confined between the cladding layers 11 and 13.

[0066] Light emitted from the active layer 12 enters the interior of the phase modulation layer 15, forming a predetermined pattern corresponding to the lattice structure inside the phase modulation layer 15. Laser light emitted from the phase modulation layer 15 passes through the opening 17a from the back surface 10b and is directly output to the outside of the S-iPMSEL1. Alternatively, laser light emitted from the phase modulation layer 15 is reflected in the electrode 16, and then outputs to the outside of the S-iPMSEL1 from the back surface 10b through the opening 17a. In this case, the signal light (measurement light 105) contained in the laser light is emitted in any two-dimensional direction, including a direction perpendicular to the main surface 10a or a direction inclined relative to the main surface 10a. The signal light forms the desired optical image. The signal light mainly consists of the first and second order laser light. The third order laser light is not output from the phase modulation layer 15 of this embodiment.

[0067] Figure 3 This is a top view of the phase modulation layer 15. As shown in the figure, the phase modulation layer 15 comprises a base layer 15a made of a first refractive index medium and multiple regions 15b with different refractive indices made of a second refractive index medium with a refractive index different from that of the first refractive index medium. Figure 3 In this design, an imaginary square lattice is defined in the XY plane for the phase modulation layer 15. One side of the square lattice is parallel to the X-axis, and the other side is parallel to the Y-axis. Square-shaped unit constitutive regions R are defined in a two-dimensional configuration, centered at the lattice point O of the square lattice, along multiple columns along the X-axis and multiple rows along the Y-axis. If the XY coordinates of each unit constitutive region R are defined at the centroid position of each unit constitutive region R, then these centroid positions coincide with the lattice point O of the imaginary square lattice. Multiple regions 15b with different refractive indices are, for example, sequentially arranged within each unit constitutive region R. The planar shape of the different refractive index regions 15b is, for example, circular. The lattice point O can be located outside or inside the different refractive index regions 15b.

[0068] The proportion of the area S of different refractive index regions 15b within a unit constitutive region R is called the fill factor (FF). If the lattice spacing of the square lattice is a, then the fill factor FF of the different refractive index regions 15b is assigned as S / a. 2 S represents the area of ​​the different refractive index regions 15b in the XY plane. For example, when the different refractive index regions 15b are circular, the fill factor FF is assigned as S = π(d / 2) using the diameter d of the circle. 2 In the case where the shape of 15b is square in different refractive index regions, the fill factor FF is assigned as S = LA using the length LA of one side of the square. 2 .

[0069] Figure 4 This is an enlarged representation of the unit constitutive region R. As shown in the figure, each of the different refractive index regions 15b has a centroid G. Here, let φ(x, y) be the angle formed by the vector from lattice point O towards the centroid G and the X-axis. x represents the position of the x-th lattice point on the X-axis, and y represents the position of the y-th lattice point on the Y-axis. When the rotation angle φ is 0°, the direction of the vector connecting lattice point O and the centroid G is consistent with the positive direction of the X-axis. Furthermore, let the length of the vector connecting lattice point O and the centroid G be r(x, y). In one example, r(x, y) is constant overall in the phase modulation layer 15 regardless of x and y.

[0070] like Figure 3 As shown, based on the phase pattern corresponding to the desired optical image, the direction of the vector connecting the grid point O and the centroid G is individually set for each grid point O, i.e., the rotation angle φ around the grid point O of the centroid G in different refractive index regions 15b. The phase pattern, i.e., the rotation angle distribution φ(x, y), has specific values ​​for each position determined by the values ​​of x and y, but is not necessarily limited to being represented by a specific function. The rotation angle distribution φ(x, y) is determined by extracting the phase distribution from the complex amplitude distribution obtained by performing a Fourier transform on the desired optical image. When obtaining the complex amplitude distribution based on the desired optical image, the reproducibility of the beam pattern can be improved by applying repetitive algorithms such as the Gerchberg-Saxton (GS) method, which is generally used in computational holography.

[0071] Figure 5 This is a top view illustrating an example of a roughly periodic refractive index structure applied within a specific region of the phase modulation layer. Figure 5 In the example shown, a roughly periodic structure for emitting a target beam pattern is formed inside the inner region RIN of the square (e.g., Figure 3(Structure shown). On the other hand, in the outer region ROUT surrounding the inner region RIN, circular regions of different refractive indices with the same centroid are arranged at the lattice points of the square lattice. The fill factor FF in the outer region ROUT is set to, for example, 12%. The lattice spacing of the imaginary square lattice is the same (=a) both inside the inner region RIN and in the outer region ROUT. In this structure, light is also distributed in the outer region ROUT, thus suppressing the generation of high-frequency noise (so-called window function noise) caused by abrupt changes in light intensity at the periphery of the inner region RIN. In addition, light leakage in the in-plane direction can be suppressed, and a reduction in threshold current can be expected.

[0072] Figure 6 This is a diagram illustrating the relationship between the optical image obtained by imaging the output beam pattern of the S-iPMSEL1 and the rotation angle distribution φ(x, y) on the phase modulation layer 15. The center Q of the output beam pattern is not limited to being located on an axis perpendicular to the main surface 10a of the semiconductor substrate 10, but can also be positioned on a vertical axis. Figure 6 For ease of explanation, we assume that the center Q is located on an axis perpendicular to the principal plane 10a. Figure 6 The diagram shows the four quadrants with the center Q as the origin. Figure 6 In the example, the letter "A" appears in the third quadrant, and a symbol representing the letter "A" rotated 180 degrees appears in the first quadrant. When the output beam pattern is a rotationally symmetric light image (e.g., a cross, a circle, a double circle, etc.), these are superimposed and observed as a single light image. For example... Figure 4 As shown, when the centroid G of different refractive index regions 15b of S-iPMSEL1 is offset in the circumferential direction around lattice point O, as... Figure 6 As shown, there is no intensity difference between the output beam pattern in the first quadrant and the output beam pattern in the third quadrant, but as follows... Figure 14 As shown, by making the centroids G of the different refractive index regions 15b of S-iPMSEL1 offset on a straight line passing through the lattice point O, an intensity difference can be made between the output beam pattern in the first quadrant and the output beam pattern in the third quadrant.

[0073] The optical image of the output beam pattern of the S-iPMSEL1 includes at least one of the following: spots, dots, straight lines, crosses, line drawings, grid patterns, photographs, striped patterns, CG (computer graphics), and text. To obtain the desired optical image, the rotation angle distribution φ(x, y) of different refractive index regions 15b on the phase modulation layer 15 is determined by the following steps.

[0074] As a first prerequisite, in an XYZ orthogonal coordinate system defined by the Z-axis aligned with the normal direction and the X-Y plane aligned with one side of the phase modulation layer 15 containing multiple regions 15b with different refractive indices, an imaginary square lattice consisting of regions R consisting of M1 (an integer greater than 1) × N1 (an integer greater than 1) square units is set on the X-Y plane.

[0075] As a second prerequisite, such as Figure 7 As shown, let the coordinates (ξ, η, ζ) in the XYZ orthogonal coordinate system satisfy the following relationships with the spherical coordinates (r, θrot, θtilt) defined by the length r of the moving radius, the tilt angle θtilt from the Z axis, and the rotation angle θrot from the specific X axis on the XY plane, as shown in equations (1) to (3). Figure 7 It is a diagram used to illustrate the coordinate transformation from spherical coordinates (r, θrot, θtilt) to coordinates (ξ, η, ζ) in the XYZ orthogonal coordinate system. The coordinates (ξ, η, ζ) represent the light image on the design in real space, that is, on a specified plane in the XYZ orthogonal coordinate system.

[0076] Let the beam pattern, equivalent to the light image output from S-iPMSEL1, be a set of bright spots pointing in the direction defined by angles θtilt and θrot. Let θtilt and θrot be the angles converted to the normalized wavenumbers defined by equation (4), i.e., the coordinate values ​​kx on the Kx-axis corresponding to the X-axis, and the normalized wavenumbers defined by equation (5), i.e., the coordinate values ​​ky on the Ky-axis corresponding to the Y-axis and orthogonal to the Kx-axis. The normalized wavenumber is the wavenumber 2π / a, which normalizes the grid spacing of an imaginary square lattice to 1.0. In this case, within the wavenumber space defined by the Kx-axis and Ky-axis, a specific wavenumber range containing the beam pattern, equivalent to the light image, is composed of square-shaped image regions FR, each consisting of M2 (an integer greater than 1) × N2 (an integer greater than 1). The integer M2 need not be identical to the integer M1. Similarly, the integer N2 need not be identical to the integer N1. Equations (4) and (5) are disclosed, for example, in Y. Kurosaka et al., "Effects of non-lasing band in two-dimensional photonic-crystal lasers clarified using omnidirectional band structure", Opt. Express 20, 21773-21783 (2012).

[0077] [Number 1]

[0078] ξ=r sinθ tilt cosθ rot…(1)

[0079] [Number 2]

[0080] η = r sinθ tilt sinθ rot …(2)

[0081] [Number 3]

[0082] ζ=r cosθ tilt …(3)

[0083] [Number 4]

[0084]

[0085] [Number 5]

[0086]

[0087] a: Lattice constant of an imaginary square lattice

[0088] λ: Oscillation wavelength of S-iPMSEL1

[0089] As a third prerequisite, in wavenumber space, with j as the imaginary unit, the complex amplitude F(x, y) is obtained by the following equation (6), which is the image region FR(kx, ky) specifically defined by the coordinate components kx (integers above M2-1) in the Kx-axis direction and the coordinate components ky (integers above N2-1) in the Ky-axis direction, through their respective two-dimensional inverse discrete Fourier transforms, into the region R(x, y) on the X-Y plane specifically defined by the coordinate components x (integers above M1-1) in the X-axis direction and the coordinate components y (integers above N1-1) in the Y-axis direction. Let the amplitude term be A(x, y) and the phase term be P(x, y). Then, the complex amplitude F(x, y) is defined by the following equation (7). As a fourth prerequisite, the unit constitutive region R(x,y) is defined by the s-axis and t-axis, which are parallel to the X-axis and Y-axis respectively and orthogonal to the lattice point O(x,y) that becomes the center of the unit constitutive region R(x,y).

[0090] [Number 6]

[0091]

[0092] [Number 7]

[0093] F(x,y)=A(x,y)×exp[jP(x,y)]…(7)

[0094] Under the aforementioned first to fourth preconditions, the phase modulation layer 15 is configured to satisfy the following fifth and sixth conditions. Specifically, within a unit constitutive region R(x, y), it is configured with the centroid G far from the lattice point O(x, y), thereby satisfying the fifth condition. With the length r2(x, y) of the line segment from the lattice point O(x, y) to the corresponding centroid G set to a common value in each of the M1 × N1 unit constitutive regions R, corresponding regions 15b with different refractive indices are configured within the unit constitutive region R(x, y) such that the angle φ(x, y) formed by the line segment connecting the lattice point O(x, y) and the corresponding centroid G and the s-axis satisfies the following relationship, thereby satisfying the sixth condition:

[0095] φ(x, y) = C × P(x, y) + B

[0096] C: Proportional constant, and for example, 180° / π

[0097] B: An arbitrary constant, for example, 0

[0098] Next, the M-point oscillation of S-iPMSEL1 will be explained. In order to perform the M-point oscillation of S-iPMSEL1, it can be assumed that the interlattice spacing a of the hypothetical square lattice, the emission wavelength λ of the active layer 12, and the equivalent refractive index n of the mode satisfy the condition λ=(√2)n×a. Figure 8 This is a top view representing the reciprocal lattice space of the phase modulation layer of an S-iPMSEL oscillating at point M. Point P in the figure represents the reciprocal lattice point. Arrow B1 in the figure represents the basic reciprocal lattice vector, and arrows K1, K2, K3, and K4 represent four in-plane wavenumber vectors. The in-plane wavenumber vectors K1 to K4 each have a wavenumber spread SP based on the rotation angle distribution φ(x, y).

[0099] The shape and size of the wavenumber spread SP are the same as those in the case of the Γ-point oscillation described above. In the S-iPMSEL1 oscillating at point M, the magnitudes of the in-plane wavenumber vectors K1 to K4 (i.e., the magnitudes of the standing waves in the in-plane direction) are smaller than the magnitude of the basic reciprocal lattice vector B1. Therefore, the vector sum of the in-plane wavenumber vectors K1 to K4 and the basic reciprocal lattice vector B1 is not zero, and through diffraction, the wavenumber in the in-plane direction cannot be zero either. Therefore, no diffraction occurs in the direction perpendicular to the plane (Z-axis direction). Thus, in the S-iPMSEL1 oscillating at point M, no 0th-order light is output in the direction perpendicular to the plane (Z-axis direction), and no 1st-order light or -1st-order light is output in the direction inclined relative to the Z-axis direction.

[0100] In this embodiment, the phase modulation layer 15 in the S-iPMSEL1 oscillating at point M is processed as follows, thereby enabling the output of first-order light and a portion of -1-order light without outputting 0-order light. Specifically, as follows Figure 9As shown, by adding a diffraction vector V with a certain magnitude and direction to the in-plane wavenumber vectors K1 to K4, it is possible to make the magnitude of at least one of the in-plane wavenumber vectors K1 to K4 (K3 in the figure) less than 2π / λ. In other words, at least one of the in-plane wavenumber vectors K1 to K4 (K3) after adding the diffraction vector V converges within a circular region (ray) LL with a radius of 2π / λ.

[0101] exist Figure 9 In the diagram, the in-plane wavenumber vectors K1 to K4, represented by dashed lines, represent the diffraction vector V before addition, while those represented by solid lines represent the diffraction vector V after addition. The ray LL corresponds to the total internal reflection condition, and the wavenumber vector converging within the ray LL has a component perpendicular to the plane (Z-axis direction). In one example, the direction of the diffraction vector V is along the Γ-M1 axis or the Γ-M2 axis. The magnitude of the diffraction vector V is in the range of 2π / (√2)a-2π / λ to 2π / (√2)a+2π / λ. As an example, the magnitude of the diffraction vector V is 2π / (√2)a.

[0102] Next, we will discuss the magnitude and direction of the diffraction vector V used to converge at least one of the in-plane wavenumber vectors K1 to K4 into the ray LL. The following equations (8) to (11) represent the in-plane wavenumber vectors K1 to K4 before adding the diffraction vector V.

[0103] [Number 8]

[0104]

[0105] [Number 9]

[0106]

[0107] [Number 10]

[0108]

[0109] [Number 11]

[0110]

[0111] The diffusion of the wavenumber vector Δkx and Δky satisfies the following equations (12) and (13), respectively. The maximum value of the diffusion of the in-plane wavenumber vector in the x-axis direction Δkxmax and the maximum value of the diffusion in the y-axis direction Δkymax are determined by the angular diffusion of the designed light image.

[0112] [Number 12]

[0113] -Δkx max ≤Δkx≤Δkx max …(12)

[0114] [Number 13]

[0115] -Δky max ≤Δky≤Δky max …(13)

[0116] When the diffraction vector V is expressed as the following formula (14), the in-plane wavenumber vectors K1 to K4 after adding the diffraction vector V become the following formulas (15) to (18).

[0117] [Number 14]

[0118] V = (Vx, Vy) …(14)

[0119] [Number 15]

[0120]

[0121] [Number 16]

[0122]

[0123] [Number 17]

[0124]

[0125] [Number 18]

[0126]

[0127] If we assume that any one of the wavenumber vectors K1 to K4 in equations (15) to (18) converges within the ray LL, then the following equation (19) holds true.

[0128] [Number 19]

[0129]

[0130] That is, by adding the diffraction vector V that satisfies equation (19), any one of the wavenumber vectors K1 to K4 converges into the ray LL, and a portion of the first-order ray and the -1-order ray are output.

[0131] The reason for setting the size (radius) of the ray LL to 2π / λ is as follows. Figure 10 This is a diagram used to schematically illustrate the peripheral structure of a light ray LL. The diagram shows the boundary between the device and air as viewed from a direction perpendicular to the Z-axis. The magnitude of the wavenumber vector of light in a vacuum is 2π / λ, but in light... Figure 10 When light propagates in the device medium, the magnitude of the wavenumber vector Ka in the medium with refractive index n is 2πn / λ. At this point, in order for light to propagate at the boundary between the device and air, the wavenumber components parallel to the boundary need to be continuous (wavenumber conservation law).

[0132] exist Figure 10 In the case where the wavenumber vector Ka forms an angle θ with the Z-axis, the length of the wavenumber vector projected onto the plane (i.e., the in-plane wavenumber vector) Kb is (2πn / λ)sinθ. On the other hand, generally, based on the refractive index n > 1, the wavenumber conservation law does not hold when the in-plane wavenumber vector Kb within the medium is greater than 2π / λ. In this case, total internal reflection occurs, and the light cannot be extracted to the air side. The magnitude of the wavenumber vector corresponding to this total internal reflection condition is the magnitude of the ray LL, i.e., 2π / λ.

[0133] As an example of a specific way to add the diffraction vector V to the in-plane wavenumber vectors K1 to K4, consider a method in which the rotation angle distribution φ2(x, y) (second phase distribution), which is independent of the light image, and the phase distribution corresponding to the light image, i.e., the rotation angle distribution φ1(x, y) (first phase distribution), are superimposed. In this case, the rotation angle distribution φ(x, y) of the phase modulation layer 15 is expressed as φ(x, y) = φ1(x, y) + φ2(x, y). As mentioned above, φ1(x, y) corresponds to the phase of the complex amplitude when performing a Fourier transform on the light image. φ2(x, y) is the rotation angle distribution used to add the diffraction vector V that satisfies the above equation (19).

[0134] Figure 11 This is a diagram conceptually representing an example of the rotation angle distribution φ2(x, y). In this example, a first phase value φA and a second phase value φB, which differs from the first phase value φA, are arranged in a checkered pattern. In one example, the phase value φA is 0 (rad), and the phase value φB is π (rad). In this case, the first phase value φA and the second phase value φB vary for every π. This arrangement of phase values ​​allows for the preferred realization of a diffraction vector V along the Γ-M1 axis or the Γ-M2 axis. In the case of the checkered pattern, V = (±π / a, ±π / a), and the diffraction vector V and Figure 8 The wavenumber vectors K1 to K4 exactly cancel each other out. Furthermore, the angular distribution θ2(x, y) of the diffraction vector V is represented by the inner product of the diffraction vector V(Vx, Vy) and the position vector r(x, y). That is, the angular distribution θ2(x, y) of the diffraction vector V is represented by θ2(x, y) = V·r = Vxx + Vyy.

[0135] In the above embodiments, when the wavenumber diffusion based on the angular diffusion of the light image is contained within a circle of radius Δk centered at a point in wavenumber space, it can also be simply considered that: by adding the diffraction vector V to the in-plane wavenumber vectors K1 to K4 in the four directions, the magnitude of at least one of the in-plane wavenumber vectors K1 to K4 in the four directions is less than 2π / λ (ray LL). Alternatively, it can be considered that: by removing the wavenumber diffusion Δk from the in-plane wavenumber vectors K1 to K4 in the four directions and then adding the diffraction vector V, the magnitude of at least one of the in-plane wavenumber vectors K1 to K4 in the four directions is less than the value {(2π / λ)-Δk} after subtracting the wavenumber diffusion Δk from 2π / λ.

[0136] Figure 12 This is a conceptual diagram representing the aforementioned state. As shown in the diagram, if the in-plane wavenumber vectors K1 to K4, after removing the wavenumber diffusion Δk, are combined with the diffraction vector V, then the magnitude of at least one of the in-plane wavenumber vectors K1 to K4 is less than {(2π / λ)-Δk}. Figure 12 In the diagram, region LL2 is a circular region with radius {(2π / λ)-Δk}. Figure 12 In the diagram, the in-plane wavenumber vectors K1 to K4, represented by dashed lines, represent the diffraction vector V before addition, while those represented by solid lines represent the diffraction vector V after addition. Region LL2 corresponds to the total internal reflection condition considering wavenumber diffusion Δk, and the wavenumber vectors of magnitude converging within region LL2 also propagate along the direction perpendicular to the surface (Z-axis direction).

[0137] In this method, the magnitude and direction of the diffraction vector V used to converge at least one of the in-plane wavenumber vectors K1 to K4 into the region LL2 are explained. The following equations (20) to (23) represent the in-plane wavenumber vectors K1 to K4 before adding the diffraction vector V.

[0138] [Number 20]

[0139]

[0140] [Number 21]

[0141]

[0142] [Number 22]

[0143]

[0144] [Number 23]

[0145]

[0146] Here, when the diffraction vector V is expressed as the above formula (14), the in-plane wavenumber vectors K1 to K4 after adding the diffraction vector V are the following formulas (24) to (27).

[0147] [Number 24]

[0148]

[0149] [Number 25]

[0150]

[0151] [Number 26]

[0152]

[0153] [Number 27]

[0154]

[0155] In equations (24) to (27), if it is assumed that any one of the in-plane wavenumber vectors K1 to K4 converges within region LL2, then the following equation (28) holds. That is, by adding the diffraction vector V that satisfies equation (28), any one of the in-plane wavenumber vectors K1 to K4, after removing the wavenumber diffusion Δk, converges within region LL2. Even in this case, it is possible to output first-order light and a portion of -1-order light instead of 0-order light.

[0156] [Number 28]

[0157]

[0158] Figure 13 This is a top view of the phase modulation layer in the modified example. Figure 14 This is a diagram showing the positional relationship of different refractive index regions on the phase modulation layer of the modified example. For example... Figure 13 and Figure 14 As shown, in the modified example, the centroids G of the different refractive index regions 15b of the phase modulation layer 15 are arranged on the straight line D. The straight line D is a straight line that passes through the lattice point O corresponding to each unit constituting region R and is inclined relative to each side of the square lattice. That is, the straight line D is a straight line inclined relative to both the X-axis and the Y-axis. The inclination angle of the straight line D with respect to one side (X-axis) of the square lattice is θ.

[0159] The tilt angle θ is constant within the phase modulation layer 15B. The tilt angle θ satisfies 0° < θ < 90°, in one example θ = 45°. Alternatively, the tilt angle θ satisfies 180° < θ < 270°, in one example θ = 225°. When the tilt angle θ satisfies 0° < θ < 90° or 180° < θ < 270°, the line D extends from the first quadrant to the third quadrant of the coordinate plane defined by the X and Y axes. The tilt angle θ satisfies 90° < θ < 180°, in one example θ = 135°. Alternatively, the tilt angle θ satisfies 270° < θ < 360°, in one example θ = 315°. When the tilt angle θ satisfies 90° < θ < 180° or 270° < θ < 360°, the line D extends from the second quadrant to the fourth quadrant of the coordinate plane defined by the X and Y axes. Thus, the tilt angle θ becomes an angle other than 0°, 90°, 180°, and 270°.

[0160] Here, let the distance between lattice point O and the centroid G be r(x, y). x is the position of the x-th lattice point on the X-axis, and y is the position of the y-th lattice point on the Y-axis. When the distance r(x, y) is positive, the centroid G is located in the first quadrant (or the second quadrant). When the distance r(x, y) is negative, the centroid G is located in the third quadrant (or the fourth quadrant). When the distance r(x, y) is 0, lattice point O and the centroid G coincide. The preferred tilt angles are 45°, 135°, 225°, and 275°. At these tilt angles, only two of the four wavenumber vectors (e.g., in-plane wavenumber vectors (±π / a, ±π / a)) that form the standing wave at point M are phase modulated, while the other two are not phase modulated; therefore, a stable standing wave can be formed.

[0161] Based on the phase pattern corresponding to the desired optical image, the centroid G of each different refractive index region 15b and the distance r(x, y) to the lattice point O corresponding to each unit constituting region R are individually set. The phase pattern, i.e., the distribution of distance r(x, y), has specific values ​​for each position determined by the values ​​of x and y, but it does not necessarily have to be represented by a specific function. The distribution of distance r(x, y) is determined based on the distribution of the phase distribution extracted from the complex amplitude distribution obtained by performing an inverse Fourier transform on the desired optical image.

[0162] like Figure 14As shown, when the phase P(x, y) at a certain coordinate (x, y) is P0, the distance r(x, y) is set to 0. When the phase P(x, y) is π + P0, the distance r(x, y) is set to the maximum value R0. When the phase P(x, y) is -π + P0, the distance r(x, y) is set to the minimum value -R0. For intermediate phases P(x, y), a distance r(x, y) is chosen such that r(x, y) = {P(x, y) - P0} × R0 / π. The initial phase P0 can be arbitrarily set.

[0163] If the grid spacing of the hypothetical square lattice is denoted as a, then the maximum value R0 of r(x, y) is within the range of, for example, the following equation (29). When determining the complex amplitude distribution based on the desired light image, the reproducibility of the beam pattern can be improved by applying repetitive algorithms such as the Gerchberg-Saxton (GS) method commonly used in holographic generation.

[0164] [Number 29]

[0165]

[0166] In this method, the desired optical image can be obtained by determining the distribution of distances r(x, y) of different refractive index regions 15b of the phase modulation layer 15. Under the same first to fourth preconditions as in the above embodiment, the phase modulation layer 15 is configured to satisfy the following condition: The corresponding different refractive index regions 15b are arranged within a unit configuration region R(x, y) such that the distance r(x, y) from the lattice point O(x, y) to the centroid G of the corresponding different refractive index region 15b satisfies the following relationship:

[0167] r(x,y)=C×(P(x,y)-P0)

[0168] C: Proportional constant, and for example, R0 / π

[0169] P0: An arbitrary constant, for example, 0

[0170] When the phase P(x, y) at a certain coordinate (x, y) is P0, the distance r(x, y) is set to 0. When the phase P(x, y) is π + P0, the distance r(x, y) is set to its maximum value R0. When the phase P(x, y) is -π + P0, the distance r(x, y) is set to its minimum value -R0. To obtain the desired light image, an inverse Fourier transform is performed on the light image, and the distribution of the distance r(x, y) corresponding to the phase P(x, y) of the complex amplitude is assigned to multiple regions 15b with different refractive indices. The phase P(x, y) and the distance r(x, y) can also be proportional to each other.

[0171] In this method, similar to the above-described implementation, the lattice spacing a of the hypothetical square lattice and the emission wavelength λ of the active layer 12 satisfy the condition of M-point oscillation. When considering the reciprocal lattice space on the phase modulation layer 15, the magnitude of at least one of the in-plane wavenumber vectors in the four directions containing wavenumber diffusion based on the distance r(x, y) can be less than 2π / λ (ray).

[0172] In this method, by performing the following process on the phase modulation layer 15 in the S-iPMSEL1 oscillating at point M, instead of outputting 0th order light into the light beam, a portion of 1st order light and -1st order light are output. Specifically, as follows... Figure 9 As shown, by adding a diffraction vector V with a certain magnitude and direction to the in-plane wavenumber vectors K1 to K4, the magnitude of at least one of the in-plane wavenumber vectors K1 to K4 can be made less than 2π / λ. That is, at least one of the in-plane wavenumber vectors K1 to K4 after adding the diffraction vector V converges into a circular region (ray) LL with a radius of 2π / λ. By adding the diffraction vector V that satisfies the above equation (19), any one of the in-plane wavenumber vectors K1 to K4 converges into the ray LL, and a portion of the first-order ray and a portion of the -1-order ray are output.

[0173] like Figure 12 As shown, by removing the wavenumber diffusion Δk (i.e., the four-directional in-plane wavenumber vectors in the square lattice PCSEL oscillating at point M) from the four-directional in-plane wavenumber vectors K1 to K4 and adding the diffraction vector V, the magnitude of at least one of the four-directional in-plane wavenumber vectors K1 to K4 can be made smaller than the value {(2π / λ)-Δk} after subtracting the wavenumber diffusion Δk from 2π / λ. That is, by adding the diffraction vector V that satisfies the above equation (28), any one of the in-plane wavenumber vectors K1 to K4 converges within region LL2, and a portion of the first-order light and the -1-order light are output.

[0174] As an example of a specific method for adding the in-plane wavenumber vectors K1 to K4 to the diffraction vector V, consider a method in which the distance distribution r2(x, y) (second phase distribution), which is independent of the light image, and the phase distribution corresponding to the light image, i.e., the distance distribution r1(x, y) (first phase distribution), are overlapped. In this case, the distance distribution r(x, y) of the phase modulation layer 15 is represented as:

[0175] r(x,y)=r1(x,y)+r2(x,y).

[0176] As mentioned above, r1(x, y) corresponds to the phase of the complex amplitude when performing a Fourier transform on the light image. r2(x, y) is the distance distribution used to add the diffraction vector V that satisfies the above equation (19) or equation (28). Specific examples of the distance distribution r2(x, y) are as follows: Figure 11 same.

[0177] [First Embodiment of the Three-Dimensional Measurement Device]

[0178] Figure 15 This is a schematic diagram showing the structure of the three-dimensional measuring device 101A according to the first embodiment. As shown in the figure, the three-dimensional measuring device 101A comprises a single light source unit 102, a plurality of (pairs) camera units 103, and a measuring unit 104. The light source unit 102 is composed of the S-iPMSEL1 that oscillates at the M point as described above. The measuring light 105 emitted from the light source unit 102 is irradiated onto a certain area of ​​the surface of the measured object SA placed on the stage 106. The stage 106 may also be a scanning stage capable of scanning in a two-dimensional or three-dimensional direction. When the irradiation range of the measuring light 105 is sufficiently large relative to the measurement range of the measured object SA, the arrangement of the stage 106 may be omitted.

[0179] In this embodiment, the defined pattern of the measuring light 105 is a periodic pattern W1 composed of any one of a dot pattern, a bar pattern, and a grid pattern. Figure 16 In the example, the periodic pattern W1 of the measuring light 105 is a periodic dot pattern represented by an image area of ​​100×100 pixels. In this dot pattern, the dots are arranged in a matrix, and the period of the dots is 5 pixels in both directions. Figure 17 This is an example of a far-field image representing a periodic pattern. Figure 17 (a) is the far-field image of a 40×40 dot matrix. Figure 17 (b) is the far-field image with 60×60 dots. Figure 17 (c) is the far-field image with 80×80 dots. Figure 17 (d) is a far-field image with 120×120 dots. The driving conditions for the light source 102 are: current 0.5A, pulse width 50ns, pulse interval 5μs, and temperature 25°C. The center of the image is the center in the direction perpendicular to the plane of the measuring light 105, and the calibration lines in the image correspond to 15°. The far-field images shown in these images are designed with the dots arranged in a matrix on a flat screen, and the distortion of the arrangement in the parts far from the center is caused by the optical system of the measurement system.

[0180] The imaging unit 103 is a device sensitive to the measurement light 105 emitted from the light source unit 102. The imaging unit 103 can be, for example, a CCD (Charge Coupled Device) camera, a CMOS (Complementary MOS) camera, or other two-dimensional image sensors. The imaging unit 103 captures an image of the measured object SA in a state where it is illuminated by the measurement light 105, and outputs an output signal representing the imaging result to the measurement unit 104.

[0181] The measurement unit 104 is composed of a computer system including components such as a processor and memory. The measurement unit 104 executes various control functions via the processor. Examples of computer systems include personal computers, microcomputers, cloud servers, and smart devices (smartphones, tablets, etc.). The measurement unit 104 can be composed of a PLC (programmable logic controller) or an integrated circuit such as an FPGA (field-programmable gate array).

[0182] The measuring unit 104 is communicatively connected to the camera unit 103, and performs three-dimensional shape measurement of the object SA based on the output signal input from the camera unit 103. In this embodiment, the measuring unit 104 measures the three-dimensional shape of the object SA based on an active stereo method using a periodic pattern W1. Here, as an example, a three-dimensional shape measurement method based on the principle of parallel equipotential stereo is shown. Let the parallax of a pair of camera units 103, 103 be D, the distance between the pair of camera units 103, 103 be b, the focal length of the pair of camera units 103, 103 be f, and the distance from the pair of camera units 103, 103 to the object SA be Z. In this case, the parallax D is assigned the value D = (f / Z)b. The distance b between the camera units 103, 103 and the focal length of the camera units 103, 103 are both inherent values. Therefore, by calculating the parallax D, the distance Z from the object SA can be calculated.

[0183] In this embodiment, a measuring light 105 having a periodic pattern W1 is irradiated onto the object SA being measured. At this time, the measuring unit 104 can determine the same point of the periodic pattern W1 captured by the imaging units 103, 103 respectively. Furthermore, three-dimensional measurements using images with low texture, which is a technical problem in passive stereo methods, and three-dimensional measurements in dark areas can be performed. By using the periodic pattern W1, represented by periodic dots, deviations in the pattern density of the measuring light 105 are suppressed, and uneven measurement accuracy caused by the illumination position of the measuring light 105 can be suppressed.

[0184] In this embodiment, for example, can also be used. Figure 18 The random dot pattern W2 shown is used to replace the periodic pattern W1. The random dot pattern W2 is used to... Figure 16 The dot pattern shown is a two-dimensional random displacement of each dot from its position at a grid point within a fundamental periodic region (a rectangular area enclosed by line segments perpendicular to the midpoints between adjacent grid points). As an example, a random number φ(ix, iy) can be assigned to each dot located at a grid point, and based on this random number φ, each dot can be displaced from its position at the grid point.

[0185] In this case, the random dot pattern W2 has a pseudo-period, thus suppressing deviations in the pattern density of the measuring light 105 and preventing uneven measurement accuracy caused by the illumination position of the measuring light 105. Furthermore, by using the random dot pattern W2 instead of a periodic dot pattern, misidentification when photographing the same point of the dot pattern through different camera units 103 can be suppressed. Therefore, the measurement accuracy of parallax D can be improved, thereby enhancing the accuracy of three-dimensional shape measurement.

[0186] In this embodiment, it is also possible to use Figure 19 The periodic pattern W1 is replaced by a pattern W3 with uniform density. Since the emitted light from the S-iPMSEL1 is laser light, speckle may appear in the scattered light. Furthermore, unexpected speckle noise can sometimes be introduced during phase calculations. Therefore, even when using the pattern W3 with uniform density, a random dot pattern is formed in the pattern of the measurement light 105. By using this random dot pattern, misidentification when capturing the same point of the dot pattern through different camera units 103 can be suppressed.

[0187] Figure 20 This figure shows an example of a Far Field Pattern (FFP) with a pattern W3 of uniform density. In this example, the pulse width of the measurement light 105 is set to 50 ns, the repetition interval is set to 5 μs, and the FFP is observed at room temperature. Additionally, a hue correction of +40% brightness and -40% contrast is performed. In this figure, it can be confirmed that even when using a pattern W3 with uniform density, a random dot pattern is formed in the pattern of the measurement light 105.

[0188] exist Figure 15 In the example, the three-dimensional measuring device 101A has a single light source unit 102, but the three-dimensional measuring device 101A may also have multiple light source units 102. In this case, by illuminating different areas of the measured object SA with the measuring light 105 from each light source unit 102, the measuring area can be expanded without scanning the stage 106. With this structure, the stage 106 can be omitted.

[0189] [Second Embodiment of the Three-Dimensional Measurement Device]

[0190] Figure 21This is a schematic diagram showing the structure of the three-dimensional measuring device according to the second embodiment. As shown in the figure, the three-dimensional measuring device 101B of the second embodiment is configured to include multiple light source units 102, a single imaging unit 103, and a measuring unit 104. The structures of the imaging unit 103, the light source units 102, and the measuring unit 104 are the same as those in the first embodiment. In this embodiment, the predetermined pattern of the measuring light 105 is a Gray code pattern, and the measuring unit 104 measures the three-dimensional shape of the measured object SA based on the triangulation method using the Gray code pattern.

[0191] Figure 22 This is a diagram illustrating an example of a Gray code pattern. In this example, let the number of pixels in the camera unit 103 be Nx × Ny, and this pixel is shown with respect to the X direction. If we let the pixel position n in the X direction (n is an integer from 0 to Nx-1) be an Mx-bit binary number, then the Gray code pattern W4 is represented by the XOR of the binary representation of the object number and a number that shifts the binary representation of the object number one bit to the right and adds a leading 0. That is, if the number of objects is n, then the Gray code pattern W4 is expressed by a logical expression of AND n^(n >> 1). Figure 22 In the example, we have Gray code patterns W4a to W4d for the 4-bit (4-pattern) case. To generate the Gray code pattern W4, you can use, for example, OpenCV.

[0192] In Gray code, the Hamming distance between adjacent pixels is 1. The Hamming distance refers to the number of bits that differ at corresponding positions when comparing two values ​​of the same bit length. Therefore, in Gray code with a Hamming distance of 1, even if a bit error occurs during bit stream reconstruction, the error converges to 1. In simple binary code, the positional error increases when an error occurs in the upper bit, but in Gray code, this results in noisy symbols.

[0193] When using Gray code, the configuration number of the light source unit 102 is simply the number of patterns corresponding to each bit of the binary number. That is, the Gray code patterns W4a to W4d are composed of multiple stripe-like patterns in which the 0s and 1s of each pixel from the topmost bit to the bottommost bit are set to be different. The light source unit 102 sequentially switches between the Gray code patterns W4a from the topmost bit to W4d from the bottommost bit, while simultaneously capturing images through the camera unit 103. In this case, a value X is obtained by capturing images Mx times. It is known that the position of the Xth pixel is measured based on this value X. Similarly, in the Y direction, by sequentially switching between the Gray code patterns W4a to W4d, while simultaneously capturing images through the camera unit 103, a value Y is obtained by capturing images My times. It is known that the position of the Yth pixel is measured based on this value Y.

[0194] To avoid misidentification caused by the surface color of the measured object SA, Figure 22The Gray code patterns W4a to W4d shown can also be used together with the gray code patterns that are black and white reversed. In this case, the number of light source units 102 can be set to 2Mx + 2My.

[0195] In this embodiment, for example, such as Figure 23 As shown, a sinusoidal bar pattern W5 can also be used instead of the Gray code pattern W4. Figure 23 The sinusoidal bar pattern W5 shown is a periodic bar pattern represented by an image area of ​​100×100 pixels. The period of the sinusoidal bar pattern W5 is 20 pixels. The measurement unit 104 measures the three-dimensional shape of the measured object SA based on the phase shift method using the sinusoidal bar pattern W5. In this method, multiple sinusoidal bar patterns W5 are used, for example, each subjected to a phase shift (displacement) equal to one period of the lattice pitch. As for the phase shift pattern, a pattern with a phase shift of 2π / N (N is an integer) can be prepared.

[0196] Here, an example is given using four sinusoidal bar patterns W5 with different phase shifts. The light intensity of the measuring light 105 with the four sinusoidal bar patterns W5 is set to I0 to I3 respectively, and the pixel of the imaging unit 103 is (x, y). In this case, the light intensity I0 to I3 on ​​the surface of the measured object SA is expressed by the following equations (30) to (33). Ia(x, y) is the amplitude of the grid pattern, Ib(x, y) is the background intensity, and θ(x, y) is the initial phase.

[0197] [Number 30]

[0198] I0=Ia(x,y)cos{θ(x,y)}+Ib(x,y)...(30)

[0199] [Number 31]

[0200] I1=Ia(x,y)cos{θ(x,y)+π / 2}+Ib(x,y)…(31)

[0201] [Number 32]

[0202] I2=Ia(x,y)cos{θ(x,y)+π}+Ib(x,y)...(32)

[0203] [Number 33]

[0204] I3=Ia(x,y)cos{θ(x,y)+3π / 2}+Ib(x,y)…(33)

[0205] The initial phase θ can be obtained by tanθ = -(I3 - I1) / (I2 - I0). When the phase shift number of the sinusoidal bar pattern W5 is N, the initial phase θ can be obtained by the following equation (34).

[0206] [Number 34]

[0207]

[0208] When using this phase-shifting method, by performing height conversion on the measured phase, the height of the object SA can be measured at intervals smaller than the pitch of the sinusoidal bar pattern W5. In the structure of the three-dimensional measuring device 101B, the light source section 102 can also be arranged parallel to the stripes in the sinusoidal bar pattern W5. In this case, phase shift caused by misalignment of the light source section 102 can be eliminated, and the shift in the initial phase of each of the multiple sinusoidal bar patterns W5 can be eliminated.

[0209] In this embodiment, the light source units 102 may also be arranged along two mutually orthogonal axes. In this case, by switching the measurement light 105 on and off for each axis, the height curve of the measured object SA can be obtained along two axes. For example, as Figure 24 As shown, a matrix pattern W6 that varies in a sinusoidal wave pattern along two mutually orthogonal axes can be used instead of the sinusoidal bar pattern W5. Using this matrix pattern W6, the height curve of the measured object SA can be measured simultaneously along both axes.

[0210] In this embodiment, the multiple light source units 102 can also each output a sinusoidal bar pattern W5 with different periods. In the phase-shifting method described above, the discontinuity at a phase of 2π becomes a technical problem. In contrast, when using sinusoidal bar patterns W5 with different periods, for example, as... Figure 25 As shown, by selecting coordinates that are consistent across all frequencies, the discontinuity at phase 2π can be improved, enabling high-precision three-dimensional measurements with a few patterns. Improving the discontinuity at phase 2π allows for the expansion of the measurement range for three-dimensional shape measurements or high-precision measurement of objects SA with significant convexity or concavity.

[0211] In this embodiment, the measuring unit 104 can also measure the three-dimensional shape of the object SA based on the sampling moiré method using a sinusoidal bar pattern W5. In the sampling moiré method, the grid of the sinusoidal bar pattern W5 projected onto the surface of the object SA is deformed according to the height of the object SA. Here, in the image captured by the imaging unit 103, the stripe spacing of a sinusoidal pattern with a phase shift number N pre-adjusted at the height of the reference plane corresponds to N pixels of the camera. Here, the phase shift number N is set to 4. A sinusoidal pattern is illuminated, and the pixels of the imaging unit 103 are sampled for each N=4 pixels, thereby, as Figure 26 As shown in (a), four patterns P1 to P4 can be obtained for each 4-pixel image (with the 3 pixels between the image pixels being sparsified). Between these patterns P1 to P4, the image pixels are shifted for each pixel, linearly complementing the brightness values ​​of the image pixels. Thus, as shown... Figure 26 As shown in (b), moiré fringe patterns M1 to M4 with phase shifts can be obtained. By using these moiré fringe patterns M1 to M4 and applying the phase shift method described above, the height of the object SA can be measured at an interval smaller than the pitch of the sinusoidal fringe pattern W5. Compared with the phase shift method described above, this method can reduce the number of irradiated sinusoidal patterns, making the light source section 102 more compact.

[0212] In this embodiment, for example, such as Figure 27 As shown, an overlapping pattern W7, which combines a sinusoidal bar pattern W5 and a random dot pattern W2, can be used instead of the sinusoidal bar pattern W5. By using this overlapping pattern W7, the height of the object SA can be measured at an interval smaller than the pitch of the sinusoidal bar pattern W5. Furthermore, by combining the random dot patterns, discontinuities at phase 2π can be improved, enabling high-precision three-dimensional measurements with a small number of patterns. Figure 28 As shown, the overlapping pattern can also be an overlapping pattern W8 that overlaps a matrix pattern W6 that varies in a sinusoidal wave shape and a random dot pattern W2. In this case, in addition to the effects described above, the height curve of the measured object SA can be measured simultaneously along two axes.

[0213] In this embodiment, both a sinusoidal bar pattern W5 and a Gray code pattern W4 can be used. In this case, the measurement unit 104 measures the three-dimensional shape of the object SA based on the phase-shift method using the sinusoidal bar pattern W5 and the triangulation method using the Gray code pattern W4. In this case, pixel-level measurement can be performed using the triangulation method using the Gray code pattern W4, and sub-pixel-level measurement can be performed using the phase-shift method using the sinusoidal bar pattern W5. Furthermore, by using Gray code, discontinuities at a phase of 2π can be improved, enabling high-precision three-dimensional measurement with a small number of patterns.

[0214] [Third Embodiment of the Three-Dimensional Measurement Device]

[0215] Figure 29 This is a schematic diagram showing the structure of the three-dimensional measuring device according to the third embodiment. As shown in the figure, the three-dimensional measuring device 101C of the third embodiment is configured to include multiple light source units 102, multiple (pair) camera units 103, and a measuring unit 104. The structures of the camera units 103, light source units 102, and measuring units 104 are the same as those in the first embodiment. In this embodiment, the predetermined pattern of the measuring light 105 is a sinusoidal bar pattern W5, and the measuring unit 104 measures the three-dimensional shape of the measured object SA based on the phase-shifting method and the active stereo method using the sinusoidal bar pattern W5.

[0216] In this embodiment, by performing height conversion on the measured phase, the height of the object SA can be measured at intervals smaller than the pitch of the sinusoidal bar pattern W5. Furthermore, by combining the active stereo method using multiple camera units 103, discontinuities at phase 2π can be improved, enabling high-precision three-dimensional measurement with a small number of patterns. When using the active stereo method, the aforementioned dot pattern can also be switched simultaneously.

[0217] [Phase Shift of a Sinusoidal Bar Pattern Based on S-iPMSEL]

[0218] In S-iPMSEL1, in addition to the designed primary beam, a secondary beam symmetrical about the normal to the exit surface is also output (see reference). Figure 6 Therefore, when performing a phase shift of a sinusoidal stripe pattern W5, considering a sinusoidal wave with overlapping ±1 order light, the direction of the stripe displacement between the 1st and -1st order light reverses, and the pattern may deviate from the design. To simplify the explanation, consider the displacement of the stripe in the X-axis direction. In this case, the complex amplitude of the 1st order light is represented by the following equation (35). The complex amplitude of the -1st order light is the complex amplitude of the light emitted at a position symmetrical to the 1st order light relative to the surface normal, and is represented by the following equation (36). In the formula, k (=kx、ky、kz) is the wavenumber vector (magnitude 2π / λ), λ is the wavelength, ω is the frequency of light, Δθ is the phase shift, a1 is the first-order light amplitude (the component caused by the phase distribution of the actual aperture configuration relative to the ideal phase distribution), K is the wavenumber of the fringe of the sine wave (=2π / Λ (Λ is the period of the sine wave)), θ is the phase shift of the sine wave, and (x、y、z) are the coordinates of the projected beam.

[0219] [Number 35]

[0220] A1=a1cos(Kx+θ)exp{j(ωt-k x xk y ykz z)}…(35)

[0221] [Number 36]

[0222] A -1 =A -4 1cos(Kx+θ)exp{j(ωt+k x x+k y yk z z)}…(36)

[0223] At this point, the combined amplitude A can be calculated using the following equation (37) based on the amplitudes of the first and -1 light.

[0224] [Number 37]

[0225] A=cos(Kx+θ){a1exp[j{ωt-k z -(k x x+k y y)}]+a -1 exp[j{ωt-k z z+(k x x+k y y)}]}…(37)

[0226] The actual light intensity is proportional to the square of the combined amplitude A, and therefore can be obtained by the following equation (38).

[0227] [Number 38]

[0228]

[0229] The period of the fundamental light wave is sufficiently smaller than the period of the sine wave (λ << Λ). Therefore, the wavenumber k of the fundamental light wave is sufficiently larger than the wavenumber K of the fringe of the sine wave (k >> K). Therefore, it is also considered that the terms corresponding to the change of k in the above equation (38) can be averaged. In this case, the intensity I of the light after ±1 times light overlap can be approximated by the following equation (39).

[0230] [Number 39]

[0231]

[0232] According to these formulas, when performing a phase shift in a sinusoidal bar pattern W5, even with ±1 times of light overlap, the fringes maintain their sinusoidal shape during displacement. Furthermore, it is known that in a sinusoidal pattern with ±1 times of light overlap, the actual light intensity (the square of the sum of the amplitudes of ±1 times of light) is halved relative to the design pattern (the amplitude of the first light wave), and the phase shift becomes twice that of one period. Therefore, to achieve a phase shift of π / 2 at, for example, the final light intensity, the design value for the phase shift of the first light wave amplitude can be set to π / 4. The same applies to a sinusoidal matrix pattern W6 with a period in the two-axis direction.

[0233] like Figure 4 As shown, when the centroid G of the different refractive index regions 15b in S-iPMSEL1 is shifted in the circumferential direction around the lattice point O, the amplitudes a of the first and second order rays become equal. On the other hand, as... Figure 14 As shown, when the centroid G of the different refractive index regions 15b in S-iPMSEL1 passes through the lattice point O and is offset on a straight line D that is inclined relative to each side of the square lattice, the amplitudes a of the first and -1st orders become different values. Even in either case, a sinusoidal pattern of overlapping ±1st orders can be used.

[0234] When the primary and secondary beams are asymmetrical patterns, overlap between them can prevent the desired pattern from being achieved. For example, the structure of each bright spot of the primary beam exhibits asymmetrical diffusion, resulting in a blurred pattern. In this case, the emission region of the primary beam can be defined as a region with a solid angle of π. For instance, by defining the emission region of the primary beam as the first and second quadrants, and the emission region of the secondary beam as the fourth and third quadrants, overlap between the primary and secondary beams can be avoided. This suppresses the diffusion of bright spots caused by the overlap of the primary and secondary beams. When the lattice pattern is shifted using a phase-shifting method, the shift direction of the secondary beam is reversed relative to the shift direction of the primary beam. Therefore, it is preferable to reverse the phase obtained through the phase-shifting operation along with the respective emission regions of the primary and secondary beams. On the other hand, even without the aforementioned problems, an image with no overlap between the primary and secondary beams and low noise can be obtained. In this case, the projection areas of the primary and secondary beams can be used separately without overlap.

[0235] [Example of light source and camera configuration]

[0236] Figure 30 This is a schematic perspective view showing an example of the configuration of the light source and the camera unit. For example... Figure 30As shown, in constructing the three-dimensional measuring device 101, the light source unit 102 and the camera unit 103 can be disposed on the surface of the three-dimensional object 111. The three-dimensional object 111 constitutes the probe portion corresponding to the three-dimensional measuring devices 101A to 101C. The three-dimensional object 111 is formed into a cylindrical shape, for example, from metal or resin. The three-dimensional object 111 can be rigid or flexible. The three-dimensional object 111 can have an internal space.

[0237] The light source unit 102 and the camera unit 103 are arranged at regular intervals (in this case, a phase angle of 45°) on the circumferential surface 111a of the cylindrical three-dimensional object 111 along the circumferential direction. Figure 30 In the example, a group of camera units 103, a group of light sources 102, and another group of camera units 103 are arranged at intervals from the front end to the base end of the three-dimensional object 111. When viewing the three-dimensional object 111 from the long side direction, the camera units 103, light sources 102, and another group of camera units 103 are arranged in a row, and these groups constitute a measurement area for the measured object SA. When the three-dimensional object 111 has an internal space, the wiring for the light sources 102 and camera units 103 can be housed in this internal space. The arrangement interval between the light sources 102 and camera units 103 may not be equal. When covering the measurement range for the measured object SA, a single light source unit 102 and a single camera unit 103 may also be arranged on the three-dimensional object 111.

[0238] Figure 31 This is a schematic perspective view showing another example of the configuration of the light source and the camera unit. Figure 31 In this example, the three-dimensional object 121 is spherically shaped and disposed at the front end of a support portion 122, for example, in a cylindrical shape. The light source portion 102 and the camera portion 103 are arranged at regular intervals (in this case, a phase angle of 45°) on the spherical surface 121a of the spherical object 121 in the longitude direction. One group of camera portions 103, one group of light source portions 102, and another group of camera portions 103 are arranged at regular intervals along the latitude direction of the three-dimensional object 121. The arrangement of one group of camera portions 103, one group of light source portions 102, and another group of camera portions 103 along the longitude direction of the three-dimensional object 121 constitutes a measurement area for the measured object SA. When the three-dimensional object 121 has an internal space, wiring for the light source portions 102 and the camera portions 103 can also be accommodated within this internal space. Figure 30 Similarly, the spacing between the light source unit 102 and the camera unit 103 may not be equal. When covering the measurement range for the measured object SA, the individual light source unit 102 and the individual camera unit 103 may also be arranged on the three-dimensional object 121.

[0239] Based on the above structure, the three-dimensional objects 111 and 121, which are equipped with the light source unit 102 and the camera unit 103, can be configured as probes of the three-dimensional measuring device 101. By using these three-dimensional objects 111 and 121, the light source unit 102 and the camera unit 103 can be oriented in different directions, thus enabling the three-dimensional shape measurement of the object SA to be measured at a large solid angle. In addition, it is easy to apply to applications such as oral examinations, endoscopy, inspection of narrow parts such as the inside of tubes or gaps in walls, inspection of furniture or devices from under the floor, or to construct handheld three-dimensional measuring devices.

[0240] Figure 23 The diagram shows a sinusoidal bar pattern W5, but when forming this bar pattern, it is important to reduce noise (brightness fluctuations) between adjacent patterns. Noise between adjacent patterns is also considered a major cause of position fluctuations, for example, when applying phase-shift methods, thus affecting measurement accuracy. Therefore, when forming a bar pattern that takes into account noise reduction between adjacent patterns, for example, as... Figure 32 As shown, a structure can be adopted that combines the S-iPMSEL1 that emits a one-dimensional multi-point pattern with a one-dimensional lens 51.

[0241] exist Figure 32 In the example, the one-dimensional lens 51 is a one-dimensional concave lens 52. The medium of the one-dimensional concave lens 52 is, for example, glass. One side 52a of the one-dimensional concave lens 52 is a flat surface, and the other side 52b is a concave surface. The one-dimensional concave lens 52 is disposed on the surface of the S-iPMSEL1 (the laser emission surface) with one side 52a facing the S-iPMSEL1. The one-dimensional concave lens 52 can also be coupled to the surface of the S-iPMSEL1 and integrated with the S-iPMSEL1. The lens phase of the one-dimensional concave lens 52 is obtained by the following equation (40). In the following equation (40), φ is the lens phase, λ is the wavelength of the laser in the lens medium, and f is the focal length.

[0242] [Number 40]

[0243]

[0244] exist Figure 32 and Figure 33 In example (a), the multi-point patterned lasers La from S-iPMSEL1 are arranged at predetermined intervals in the X direction. Figure 32 In the example, the one-dimensional concave lens 52 is configured such that its concave surface extends along the X-axis. The laser La, with its multi-point pattern, remains unchanged in the X-axis direction after passing through the one-dimensional concave lens 52, diffusing only in the Y-axis direction. Therefore, by passing the multi-point patterned laser La through the one-dimensional concave lens 52, as... Figure 33 As shown in (b), a strip pattern W11 can be obtained in which the linear laser Lb diffused in the Y direction is arranged along the X-axis.

[0245] In cases where the bar pattern is made to further approximate a sine wave shape, for example, as... Figure 34 As shown in (a), the laser La forming a multi-point pattern controls the brightness of each laser to be sinusoidal about the X-axis. This multi-point patterned laser La is passed through a one-dimensional concave lens 52. Figure 34 In the bar pattern W12 shown in (b), the linear lasers Lb diffused in the Y direction are arranged along the X-axis direction, and the brightness of each laser Lb varies in a sinusoidal manner with respect to the X-axis direction.

[0246] exist Figure 33 (a) and Figure 34 In (a), the multi-point patterned lasers La are arranged in a straight line along the X-axis, but the individual lasers La may not be arranged in a straight line; they may also be periodically or randomly offset along the Y-axis. The one-dimensional lens 51 can be any lens capable of diffusing the multi-point patterned lasers La along a one-dimensional direction, and is not limited to the one-dimensional concave lens 52. It can also be a Powell lens or a linear lens that functions as a linear generator. The one-dimensional lens 51 can be, for example, a Fresnel lens, a microlens, a metallic lens, or a flat plate lens.

[0247] When using metal lenses, for example, Figure 35 The resonant metal lens structure 53A shown in (a) can also be, for example, Figure 35 (b) shows the refractive index modulated metal lens structure 53B. For example... Figure 35 As shown in (a), when a resonant metal lens structure 53A is used, the constituent material of the metal lens structure 53A is a material having a refractive index higher than that of the layer that forms the substrate. For example, if the substrate layer (e.g., antireflective film 19) is SiN, amorphous silicon can be used as the constituent material of the metal lens structure 53A. The height and diameter of the unit lattice constituting the metal lens structure 53A are set based on the lens phase obtained from equation (40) above.

[0248] like Figure 35 As shown in (b), when using a refractive index modulated metal lens structure 53B, the metal lens structure 53B can be formed by etching the surface of the S-iPMSEL1. For example, on the surface of the S-iPMSEL1, holes 54 are formed midway from the outermost layer (e.g., antireflective film 19) to the layer below it (e.g., semiconductor substrate 10), thereby forming the refractive index modulated metal lens structure 53B. The depth and diameter of each hole 54 constituting the metal lens structure 53B are set based on the lens phase obtained from the above equation (40).

Claims

1. A three-dimensional measuring device, wherein, have: Multiple light sources illuminate the object being measured with measuring light of a predetermined pattern; The camera unit captures an image of the object being measured, which is illuminated by the measuring light; and The measuring unit measures the three-dimensional shape of the object being measured based on the imaging results of the imaging unit. The multiple light sources are each composed of S-iPMSELs. The defined pattern of the measuring light includes a bar pattern, and the bar patterns of the measuring light irradiated from the plurality of light sources each have different patterns. The plurality of light source units are arranged along a direction parallel to the stripes in the bar pattern. The measuring unit measures the three-dimensional shape of the object being measured based on the phase-shifting method using the bar pattern. The light source emits a one-dimensional multi-point pattern, which is then elongated using a one-dimensional lens to form the strip pattern.

2. The three-dimensional measuring device according to claim 1, wherein, The multiple light sources are each composed of an S-iPMSEL oscillating at point M.

3. The three-dimensional measuring device according to claim 1 or 2, wherein, The specified pattern of the measuring light is an overlapping pattern in which the periodic bar pattern and the random dot pattern overlap. The measuring unit measures the three-dimensional shape of the object being measured based on the phase-shifting method using the overlapping pattern.

4. The three-dimensional measuring device according to claim 1 or 2, wherein, The bar pattern of the measuring light irradiated by the plurality of light sources is a periodic bar pattern, each with a different phase shift. The measuring unit measures the three-dimensional shape of the object being measured based on the phase-shifting method using the bar pattern.

5. The three-dimensional measuring device according to claim 4, wherein, The bar pattern is a sinusoidal bar pattern.

6. The three-dimensional measuring device according to claim 4 or 5, wherein, The phase of the bar pattern of the measuring light irradiated from the plurality of light sources is shifted by 2π / N, where N is the phase shift number of the bar pattern.

7. A light source device, wherein, It is a light source device used in a three-dimensional measuring apparatus that measures the three-dimensional shape of an object using a phase-shifting method based on a bar pattern. It has multiple light source units that illuminate the object being measured with measuring light of a predetermined pattern. The multiple light sources are each composed of S-iPMSELs. The defined pattern of the measuring light includes the bar pattern, and the bar patterns of the measuring light irradiated from the plurality of light sources are respectively different patterns. The plurality of light source units are arranged along a direction parallel to the stripes in the bar pattern. The light source emits a one-dimensional multi-point pattern, which is then elongated using a one-dimensional lens to form the strip pattern.

Images