JP2022007906A - Three-dimensional measuring device - Google Patents

Abstract

To provide a three-dimensional measuring device that can be applied to a wider range due to reduction of the size of the device and can increase the accuracy of measurement.SOLUTION: A three-dimensional measuring device 101A includes: at least one light source unit 102 for emitting a measurement light 105 with a predetermined pattern to a measurement target object SA; at least one imaging unit 103 for imaging the object SA irradiated with the measurement light 105; and a measurement unit 104 for measuring a three-dimensional shape of the object SA on the basis of the result of imaging by the imaging unit 103. The light source unit 102 is formed of an S-iPMSEL1 of an M-point oscillation.SELECTED DRAWING: Figure 15

Description

The present disclosure relates to a three-dimensional measuring device.

As a conventional three-dimensional measurement method, for example, there is a method described in Patent Document 1. In the method of Patent Document 1, a random dot pattern is applied to the object to be measured, and two cameras capture the dot pattern at the same position. Then, based on the parallax of the two dot patterns, three-dimensional measurement of the object to be measured is carried out by the principle of triangulation.

Further, for example, the method described in Patent Document 2 is a measurement method using a phase shift method. In the method of Patent Document 2, a reference plate having a reference plane on which a grid pattern is projected is prepared, and the reference plate is translated in the normal direction by a stage. The image of the grid pattern projected on the reference plane and the image of the grid pattern projected on the object to be measured are imaged, and the spatial coordinates of the object to be measured are calculated using a table that associates the phase of the lattice pattern with the spatial coordinates. do.

U.S. Patent Application Publication No. 2008/0240502 Japanese Unexamined Patent Publication No. 2011-242178

In the method of Patent Document 1 described above, a projector is used as a light source, and in the method of Patent Document 2, an LED array is used as a light source. Therefore, there is a problem that the three-dimensional measuring device becomes relatively large. As an image pickup device, for example, an ultra-small camera having a size of 1 mm square or less has been developed. Therefore, in order to reduce the size of the three-dimensional measurement device as a whole, it is important to reduce the size of the light source. If the entire 3D measuring device can be miniaturized, it can be applied to applications such as oral examination, endoscopy, inspection of narrow areas such as the inside of pipes and gaps in walls, inspection from under the floor of furniture and devices, and handy. It is thought that it will be possible to construct a type of 3D measuring device. Further, when applying the light source to the three-dimensional measuring device, it is preferable that the light source suppresses noise and distortion of the output light from the viewpoint of improving the measurement accuracy.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a three-dimensional measuring device capable of expanding the applicable range by downsizing the device and improving the measurement accuracy. ..

The three-dimensional measuring device according to one aspect of the present disclosure includes one or a plurality of light source units that irradiate an object to be measured with measurement light having a predetermined pattern, and one or a plurality of light sources that image the object to be measured irradiated with the measurement light. It includes an image pickup unit and a measurement unit that measures the three-dimensional shape of the object to be measured based on the image pickup result by the image pickup unit, and the light source unit is configured by S-iPMSEL of M point oscillation.

In this three-dimensional measuring device, the light source unit is configured by S-iPMSEL of M point oscillation. The S-iPMSEL has a phase modulation layer having a basic layer and a plurality of different refractive index regions having different refractive indexes from the basic layer, and the position of the center of gravity of each different refractive index region is virtual according to the output light image. It deviates from the grid point position of a square grid. The S-iPMSEL can output a two-dimensional pattern of light images in a direction perpendicular to or inclined to the main surface of a substrate provided with a phase modulation layer, for example, having a size similar to that of a needle tip. Therefore, by using the S-iPMSEL as a light source, the overall size of the three-dimensional measuring device can be reduced, and the applicable range of the device can be expanded. Further, by using S-iPMSEL of M-point oscillation, it is possible to eliminate the output of 0th-order light (diffraction wave component that is not phase-modulated) different from the optical image of a desired two-dimensional pattern. As a result, it becomes possible to irradiate the object to be measured with the measurement light having a pattern without noise or distortion due to the 0th-order light, and the measurement accuracy can be improved.

The three-dimensional measuring device includes a single light source unit and a plurality of imaging units, and the predetermined pattern of the measurement light is a periodic pattern including any of a dot pattern, a stripe pattern, and a grid pattern, and is a measurement unit. May measure the three-dimensional shape of the object to be measured based on the active stereo method using a periodic pattern. In this case, three-dimensional measurement using an image with few textures and three-dimensional measurement in a dark part become possible.

The three-dimensional measuring device includes the single light source unit and a plurality of imaging units, a predetermined pattern of measurement light is a random dot pattern, and the measuring unit is based on an active stereo method using a random dot pattern. Measure the three-dimensional shape of the object to be measured. In this case, by using a random dot pattern instead of a periodic dot pattern, it is possible to suppress erroneous recognition when the same point of the dot pattern is imaged by different imaging units.

The three-dimensional measuring device includes a single light source unit and a plurality of imaging units, and a predetermined pattern of measurement light is a pattern having a uniform density, and the measuring unit uses a pattern having a uniform density. The three-dimensional shape of the object to be measured may be measured based on the active stereo method. Since the light emitted from the S-iPMSEL is a laser light, speckle may occur in the scattered light. Therefore, even when a pattern having a uniform density is used, a random dot pattern is formed in the pattern of the measurement light. By using this random dot pattern, it is possible to suppress erroneous recognition when the same point of the dot pattern is imaged by different imaging units.

The three-dimensional measuring device includes a plurality of light source units and a single image pickup unit, and a predetermined pattern of measurement light is a Gray code pattern, and the measurement unit is based on a triangulation method using a Gray code pattern. The three-dimensional shape of the object to be measured may be measured. Since the number of patterns of the Gray code pattern may be small with respect to the number of pixels of the image pickup unit, irradiation of the measurement light having the Gray code pattern can be realized by a small number of light source units. When the Gray code is used, the Hamming distance of adjacent pixels is 1, and even if a bit error occurs when restoring the bit string, the error is within 1. That is, in the Gray code, a code that is resistant to noise can be obtained.

The three-dimensional measuring device includes a plurality of light source units and a single image pickup unit, and a predetermined pattern of measurement light is a sinusoidal stripe pattern, and the measurement unit is a phase shift using a sinusoidal stripe pattern. The three-dimensional shape of the object to be measured may be measured based on the method. In this case, by converting the measured phase into height, the height of the object to be measured can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern.

The plurality of light source units may output sinusoidal stripe patterns having different periods from each other. In the phase shift method, the discontinuity at the phase 2π is a problem. On the other hand, by using sinusoidal stripe patterns having different periods from each other, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns.

The three-dimensional measuring device includes a plurality of light source units and a single image pickup unit, and a predetermined pattern of measurement light is a sinusoidal stripe pattern, and the measurement unit is a sampling moire using a sinusoidal stripe pattern. The three-dimensional shape of the object to be measured may be measured based on the method. In this case, highly accurate three-dimensional measurement can be realized with a smaller number of patterns.

The three-dimensional measuring device includes a plurality of light source units and a single image pickup unit, and a predetermined pattern of measurement light is a superimposed pattern in which a sinusoidal stripe pattern and a random dot pattern are superimposed. May measure the three-dimensional shape of the object to be measured based on the phase shift method using the superimposition pattern. In the phase shift method, the discontinuity at the phase 2π is a problem. On the other hand, by using the random dot pattern, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns.

The three-dimensional measuring device includes a plurality of light source units and a single image pickup unit, a predetermined pattern of measurement light includes a sinusoidal stripe pattern and a Gray code pattern, and the measurement unit includes sinusoidal stripes. The three-dimensional shape of the object to be measured may be measured based on a phase shift method using a pattern and a triangular survey method using a Gray code pattern. In the phase shift method, the discontinuity at the phase 2π is a problem. On the other hand, by using the Gray code, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns.

The three-dimensional measuring device includes a plurality of light source units and a plurality of imaging units, and a predetermined pattern of measurement light is a sinusoidal stripe pattern, and the measurement unit is a phase shift using a sinusoidal stripe pattern. The three-dimensional shape of the object to be measured may be measured based on the method and the active stereo method. In this case, by converting the measured phase into height, the height of the object to be measured can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern. Further, in the phase shift method, the discontinuity at the phase 2π is a problem. On the other hand, by combining the active stereo method using a plurality of imaging units, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns.

The light source unit and the image pickup unit may be arranged on the surface of a three-dimensional object. In this case, a three-dimensional object in which the light source unit and the imaging unit are arranged can be configured as a probe of the three-dimensional measuring device. By using a three-dimensional object, each pair of the light source unit and the image pickup unit can be oriented in different directions, so that the three-dimensional shape measurement of the object to be measured can be performed at a wide solid angle. In addition, for example, it can be applied to applications such as oral examination, endoscopy, inspection of narrow places such as the inside of pipes and gaps in walls, inspection from under the floor of furniture and equipment, and construction of handy type 3D measuring equipment. It will be easy.

According to the present disclosure, the application range can be expanded and the measurement accuracy can be improved by downsizing the apparatus.

It is a partial cross-sectional perspective view which shows the structure of S-iPMSEL. It is sectional drawing which shows the laminated structure of S-iPMSEL. It is a top view of the phase modulation layer. It is a figure which shows the unit composition area R in an enlarged manner. It is a top view which shows the example which applied the refractive index substantially periodic structure in the specific region of a phase modulation layer. It is a figure explaining the relationship between the optical image obtained by forming the output beam pattern of S-iPMSEL and the rotation angle distribution in a phase modulation layer. It is a figure explaining the coordinate transformation from the spherical coordinate to the coordinate in the XYZ Cartesian coordinate system. It is a top view which shows the reciprocal lattice space about the phase modulation layer of S-iPMSEL of M point oscillation. It is a conceptual diagram explaining the state which added the diffraction vector to the in-plane wave vector. It is a figure for demonstrating the peripheral structure of a light line schematically. It is a figure which conceptually shows an example of the rotation angle distribution φ2 (x, y). It is a conceptual diagram for demonstrating the state which added the diffraction vector to the in-plane wave vector of a direction minus the wave number spread. FIG. 13 is a plan view of the phase modulation layer according to the modified example. It is a figure which shows the positional relationship of the different refractive index region in the phase modulation layer which concerns on a modification. It is a schematic diagram which shows the structure of the 3D measuring apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the periodic pattern used in 1st Embodiment. It is a figure which shows an example of the far-field image of a periodic pattern. It is a figure which shows an example of the random dot pattern used in 1st Embodiment. It is a figure which shows an example of the pattern which has a uniform density used in 1st Embodiment. It is a figure which shows an example of FFP of a pattern having a uniform density. It is a schematic diagram which shows the structure of the 3D measuring apparatus which concerns on 2nd Embodiment. It is a figure which shows an example of the Gray code pattern used in 2nd Embodiment. It is a figure which shows an example of the sinusoidal stripe pattern used in 2nd Embodiment. It is a figure which shows an example of the sinusoidal matrix pattern used in 2nd Embodiment. It is a figure which shows the state of the improvement of the discontinuity in a phase 2π. It is a figure which shows an example of the moire fringe pattern used in 2nd Embodiment. It is a figure which shows an example of the superimposition pattern used in the 2nd Embodiment. It is a figure which shows another example of the superimposition pattern used in the 2nd Embodiment. It is a schematic diagram which shows the structure of the 3D measuring apparatus which concerns on 3rd Embodiment. It is a schematic perspective view which shows the arrangement example of the light source part and the image pickup part. It is a schematic perspective view which shows another arrangement example of a light source part and an image pickup part. It is a perspective view which shows the formation example of the sine and cosine-shaped stripe pattern. It is a schematic diagram which shows an example of a laser beam of a multipoint pattern and a stripe pattern using this. It is a schematic diagram which shows another example of the laser beam of a multipoint pattern and the stripe pattern using this. It is a schematic cross-sectional view which shows the structural example of the metal lens structure.

Hereinafter, preferred embodiments of the three-dimensional measuring device according to one aspect of the present disclosure will be described in detail with reference to the drawings.

The three-dimensional measuring device 101 according to the present embodiment captures one or a plurality of light source units 102 that irradiate the measured object SA with the measured light 105 having a predetermined pattern, and the measured object SA irradiated with the measured light 105. It is configured to include one or a plurality of image pickup units 103 and a measurement unit 104 that measures the three-dimensional shape of the object to be measured SA based on the image pickup result by the image pickup unit 103 (see FIG. 15 and the like). Further, the light source unit 102 is composed of S-iPMSEL (Static-integrable Phase Modulating Surface Emitting Lasers) 1 for M-point oscillation.

In the three-dimensional measuring device 101, by configuring the light source unit 102 using the S-iPMSEL1 having the size of the needle tip, the entire device can be miniaturized and the applicable range of the device can be expanded. Further, in the three-dimensional measuring device 101, by using the S-iPMSEL1 of M point oscillation, it is possible to eliminate the output of 0th-order light (diffraction wave component that is not phase-modulated) different from the optical image of the desired two-dimensional pattern. Can be done. As a result, it becomes possible to irradiate the object SA with the measurement light 105 having a pattern without noise or distortion due to the 0th-order light, and the measurement accuracy can be improved.
[S-iPMSEL of M point oscillation]

First, S-iPMSEL1 of M point oscillation will be described. FIG. 1 is a partial cross-sectional perspective view showing the configuration of S-iPMSEL. FIG. 2 is a cross-sectional view showing a laminated structure of S-iPMSEL. FIG. 1 defines an XYZ Cartesian coordinate system whose Z axis is an axis extending in the thickness direction of the S-iPMSEL1 at the center of the S-iPMSEL1.

The S-iPMSEL1 is a laser light source that forms a standing wave in the XY in-plane direction and outputs a phase-controlled plane wave in the Z-axis direction. The S-iPMSEL1 outputs a two-dimensional arbitrary-shaped optical image including a direction perpendicular to the main surface 10a of the semiconductor substrate 10 (that is, a Z-axis direction), a direction inclined with respect to the main surface 10a, or both.

As shown in FIGS. 1 and 2, the S-iPMSEL 1 has an active layer 12 as a light emitting portion provided on the semiconductor substrate 10, a pair of clad layers 11 and 13 sandwiching the active layer 12, and a clad layer 13. The contact layer 14 provided above is provided. The semiconductor substrate 10, the clad layers 11 and 13, and the contact layer 14 are made of a compound semiconductor such as a GaAs-based semiconductor, an InP-based semiconductor, or a nitride-based semiconductor. The energy bandgap of the clad layer 11 and the energy bandgap of the clad layer 13 are larger than the energy bandgap of the active layer 12. The thickness direction of the semiconductor substrate 10 and each layer 11 to 14 coincides with the Z-axis direction.

The S-iPMSEL 1 further includes a phase modulation layer 15 optically coupled to the active layer 12. In the present embodiment, the phase modulation layer 15 is provided between the active layer 12 and the clad layer 13. The thickness direction of the phase modulation layer 15 coincides with the Z-axis direction. The phase modulation layer 15 may be provided between the clad layer 11 and the active layer 12. If necessary, an optical guide layer may be provided between the active layer 12 and the clad layer 13 and at least one of the active layer 12 and the clad layer 11. The optical guide layer may include a carrier barrier layer for efficiently confining carriers in the active layer 12.

The phase modulation layer 15 is composed of a basic layer 15a made of a first refractive index medium and a second refractive index medium having a refractive index different from that of the first refractive index medium, and a plurality of different refractive index regions existing in the basic layer 15a. It is configured to include 15b. The plurality of different refractive index regions 15b include a substantially periodic structure. When the equivalent refractive index of the mode is n, the wavelength λ ₀ (= (√2) a × n, a is the lattice spacing) selected by the phase modulation layer 15 is included in the emission wavelength range of the active layer 12. ing. The phase modulation layer 15 can select a band end wavelength near the wavelength λ ₀ among the emission wavelengths of the active layer 12 and output it to the outside. The laser light incident on the phase modulation layer 15 forms a predetermined mode according to the arrangement of the different refractive index regions 15b in the phase modulation layer 15, and is used as a laser beam having a desired pattern from the surface of the S-iPMSEL1. It is emitted to the outside.

The S-iPMSEL 1 further includes an electrode 16 provided on the contact layer 14 and an electrode 17 provided on the back surface 10b of the semiconductor substrate 10. The electrode 16 is in ohmic contact with the contact layer 14, and the electrode 17 is in ohmic contact with the semiconductor substrate 10. The electrode 17 has an opening 17a. The electrode 16 is provided in the central region of the contact layer 14. The portion of the contact layer 14 other than the electrode 16 is covered with a protective film 18 (see FIG. 2). The contact layer 14 that is not in contact with the electrode 16 may be removed due to the limitation of the current range. Of the back surface 10b of the semiconductor substrate 10, the portion other than the electrode 17 is covered with the antireflection film 19 including the inside of the opening 17a. The antireflection film 19 in the region other than the opening 17a may be removed.

In S-iPMSEL1, when a driving current is supplied between the electrodes 16 and 17, electrons and holes are recombined in the active layer 12, and the active layer 12 emits light. The electrons, holes, and light generated in the active layer 12 that contribute to this light emission are efficiently confined between the clad layer 11 and the clad layer 13.

The light emitted from the active layer 12 enters the inside of the phase modulation layer 15 and forms a predetermined mode according to the lattice structure inside the phase modulation layer 15. The laser beam emitted from the phase modulation layer 15 is directly output from the back surface 10b to the outside of the S-iPMSEL1 through the opening 17a. Alternatively, the laser light emitted from the phase modulation layer 15 is reflected by the electrode 16 and then output from the back surface 10b through the opening 17a to the outside of the S-iPMSEL1. At this time, the signal light (measurement light 105) included in the laser light is emitted in a two-dimensional arbitrary direction including a direction perpendicular to the main surface 10a or a direction inclined with respect to the main surface 10a. It is this signal light that forms the desired light image. The signal light is mainly primary light and -1st order light of laser light. The 0th-order light of the laser beam is not output from the phase modulation layer 15 of the present embodiment.

FIG. 3 is a plan view of the phase modulation layer 15. As shown in the figure, the phase modulation layer 15 is a plurality of different refractive index regions 15b composed of a basic layer 15a made of a first refractive index medium and a second refractive index medium having a refractive index different from that of the first refractive index medium. And include. In FIG. 3, a virtual square grid in the XY plane is set for the phase modulation layer 15. One side of the square grid is parallel to the X-axis and the other side is parallel to the Y-axis. The square-shaped unit constituent region R centered on the grid point O of the square grid is set two-dimensionally over a plurality of columns along the X-axis and a plurality of rows along the Y-axis. If the XY coordinates of each unit constituent area R are defined by the position of the center of gravity of each unit constituent area R, these positions of the center of gravity coincide with the grid points O of the virtual square grid. A plurality of different refractive index regions 15b are provided, for example, one in each unit constituent region R. The planar shape of the different refractive index region 15b is, for example, a circular shape. The lattice point O may be located outside the different refractive index region 15b, or may be included inside the different refractive index region 15b.

The ratio of the area S of the different refractive index region 15b to the unit constituent region R is referred to as a filling factor (FF). Assuming that the lattice spacing of the square lattice is a, the filling factor FF of the different refractive index region 15b is given as S / a ² . S is the area of the different refractive index region 15b in the XY plane. For example, when the shape of the different refractive index region 15b is a perfect circle, the filling factor FF is given as S = π (d / 2) ² using the diameter d of the perfect circle. When the shape of the different refractive index region 15b is square, the filling factor FF is given as S = LA ² using the length LA of one side of the square.

FIG. 4 is an enlarged view showing the unit constituent area R. As shown in the figure, each of the different refractive index regions 15b has a center of gravity G. Here, the angle formed by the vector from the grid point O to the center of gravity G and the X axis is φ (x, y). x indicates the position of the x-th grid point on the X-axis, and y indicates the position of the y-th grid point on the Y-axis. When the rotation angle φ is 0 °, the direction of the vector connecting the lattice point O and the center of gravity G coincides with the positive direction of the X axis. Further, let r (x, y) be the length of the vector connecting the grid point O and the center of gravity G. In one example, r (x, y) is constant throughout the phase modulation layer 15, regardless of x, y.

As shown in FIG. 3, the direction of the vector connecting the grid point O and the center of gravity G, that is, the rotation angle φ around the grid point O of the center of gravity G in the different refractive index region 15b is a phase corresponding to a desired optical image. It is set individually for each grid point O according to the pattern. The phase pattern, that is, the rotation angle distribution φ (x, y) has a specific value for each position determined by the value of x, y, but is not always represented by a specific function. The rotation angle distribution φ (x, y) is determined from the complex amplitude distribution obtained by Fourier transforming the desired optical image from which the phase distribution is extracted. When determining the complex amplitude distribution from a desired optical image, the reproducibility of the beam pattern is improved by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method commonly used when calculating hologram generation. It is possible.

FIG. 5 is a plan view showing an example in which a refractive index substantially periodic structure is applied within a specific region of the phase modulation layer. In the example shown in FIG. 5, a substantially periodic structure (for example, the structure shown in FIG. 3) for emitting a target beam pattern is formed inside the inner region RIN of the square. On the other hand, in the outer region ROUT surrounding the inner region RIN, a perfect circular different refractive index region having the same center of gravity position is arranged at the grid point position of the square lattice. The filling factor FF in the outer region ROUT is set to, for example, 12%. Within the inner region RIN and the outer region ROUT, the grid spacing of the square grid virtually set is the same (= a). In the case of this structure, since the light is also distributed in the outer region ROUT, it is possible to suppress the generation of high frequency noise (so-called window function noise) caused by a sudden change in the light intensity in the peripheral portion of the inner region RIN. In addition, light leakage in the in-plane direction can be suppressed, and a reduction in the threshold current can be expected.

FIG. 6 is a diagram illustrating the relationship between the optical image obtained by forming an image of the output beam pattern of S-iPMSEL1 and the rotation angle distribution φ (x, y) in the phase modulation layer 15. The center Q of the output beam pattern is not always located on the axis perpendicular to the main surface 10a of the semiconductor substrate 10, but it can also be arranged on the axis perpendicular to the axis. In FIG. 6, for convenience of explanation, it is assumed that the center Q is on the axis perpendicular to the main surface 10a. FIG. 6 shows four quadrants with the center Q as the origin. In the example of FIG. 6, the character "A" appears in the third quadrant, and the character "A" rotated by 180 degrees appears in the first quadrant. When the output beam pattern is a rotationally symmetric optical image (for example, a cross, a circle, a double circle, etc.), they are overlapped and observed as one optical image. As shown in FIG. 4, when the center of gravity G of the different refractive index region 15b in S-iPMSEL1 is shifted in the circumferential direction around the lattice point O, the output beam in the first quadrant is shown in FIG. There is no difference in intensity between the pattern and the output beam pattern in the third quadrant, but as shown in FIG. 14 described later, when the center of gravity G of the different refraction rate region 15b in S-iPMSEL1 is shifted on a straight line passing through the lattice point O. It is possible to have an intensity difference between the output beam pattern in the first quadrant and the output beam pattern in the third quadrant.

The optical image of the output beam pattern of S-iPMSEL1 includes at least one of spots, dots, straight lines, crosses, line art, grid patterns, photographs, striped patterns, CG (computer graphics), and characters. In order to obtain a desired optical image, the rotation angle distribution φ (x, y) of the different refractive index region 15b in the phase modulation layer 15 is determined by the following procedure.

As a first precondition, the XYZ Cartesian coordinates defined by the Z axis matching the normal direction and the XY plane matching one surface of the phase modulation layer 15 including the plurality of different refractive index regions 15b. In the system, a virtual square lattice composed of M1 (integer of 1 or more) × N1 (integer of 1 or more) unit constituent regions R having a square shape is set on the XY plane.

As a second precondition, the coordinates (ξ, η, ζ) in the XYZ Cartesian coordinate system are, as shown in FIG. 7, the length r of the driving diameter, the inclination angle θtilt from the Z axis, and the XY plane. The relationship shown by the following equations (1) to (3) is satisfied with respect to the rotation angle θrot from the X axis specified above and the spherical coordinates (r, θrot, θtilt) defined by. It is assumed that there is. FIG. 7 is a diagram for explaining coordinate conversion from spherical coordinates (r, θrot, θtilt) to coordinates (ξ, η, ζ) in the XYZ Cartesian coordinate system, and is a diagram for explaining the coordinate conversion (ξ, η, ζ). A design optical image on a predetermined plane set in the XYZ Cartesian coordinate system, which is a real space, is represented.

ａ：仮想的な正方格子の格子定数
λ：Ｓ－ｉＰＭＳＥＬ１の発振波長 When the beam pattern corresponding to the optical image output from S-iPMSEL1 is a set of bright spots directed in the directions defined by the angles θtilt and θrot, the angles θtilt and θrot are defined by the following equation (4). The coordinate value kx on the Kx axis, which is the normalized wave number and corresponds to the X axis, and the Ky axis, which is the normalized wave number defined by the following equation (5) and corresponds to the Y axis and is orthogonal to the Kx axis. It shall be converted into the coordinate value ky of. The normalized wave number means a wave number standardized with a wave number of 2π / a corresponding to the grid spacing of a virtual square grid as 1.0. At this time, in the wavenumber space defined by the Kx axis and the Ky axis, the specific wavenumber range including the beam pattern corresponding to the optical image is each square-shaped M2 (integer of 1 or more) × N2 (integer of 1 or more). ) Consists of image area FR. The integer M2 does not have to match the integer M1. Similarly, the integer N2 does not have to match the integer N1. Equations (4) and (5) also include, for example, Y. Kurosaka et al., "Effects of non-lasing band intwo-dimensionalphotonic-crystal lasers clarified using omnidirectional bandstructure," Opt. Express 20, 21773-21783 (2012). ).

a: Lattice constant of a virtual square lattice
λ: Oscillation wavelength of S-iPMSEL1

As a third precondition, it is specified by the coordinate component kx in the Kx axis direction (integer of 0 or more and M2-1 or less) and the coordinate component ky in the Ky axis direction (integer of 0 or more and N2-1 or less) in the wave number space. Each image region FR (kx, ky) is specified by a coordinate component x (integer of 0 or more and M1-1 or less) in the X-axis direction and a coordinate component y (integer of 0 or more and N1-1 or less) in the Y-axis direction. The complex amplitude F (x, y) obtained by performing a two-dimensional inverse discrete Fourier transform on the unit constituent region R (x, y) on the XY plane is obtained by the following equation (6) with j as an imaginary unit. ). The complex amplitude F (x, y) is defined by the following equation (7) when the amplitude term is A (x, y) and the phase term is P (x, y). As a fourth precondition, the unit constituent region R (x, y) is parallel to the X-axis and the Y-axis, respectively, and the grid point O (x, y) at the center of the unit constituent region R (x, y). It is defined by the s-axis and the t-axis that are orthogonal to each other.

Under the first to fourth preconditions, the phase modulation layer 15 is configured to satisfy the following fifth and sixth conditions. That is, the fifth condition is satisfied by arranging the center of gravity G away from the grid point O (x, y) in the unit constituent region R (x, y). The sixth condition is a state in which the line segment length r2 (x, y) from the grid point O (x, y) to the corresponding center of gravity G is set to a common value in each of the unit constituent regions R of M1 × N1. Then, the angle φ (x, y) formed by the line segment connecting the grid point O (x, y) and the corresponding center of gravity G and the s axis is
φ (x, y) = C × P (x, y) + B
C: Proportional constant, for example 180 ° / π
B: An arbitrary constant, for example 0
The corresponding different refractive index regions 15b are arranged in the unit constituent region R (x, y) so as to satisfy the above relationship.

Next, the M point oscillation of S-iPMSEL1 will be described. For the M-point oscillation of S-iPMSEL1, the conditions such that the lattice spacing a of the virtual square lattice, the emission wavelength λ of the active layer 12, and the equivalent refractive index n of the mode are λ = (√2) n × a. It is good to meet. FIG. 8 is a plan view showing a reciprocal lattice space relating to the phase modulation layer of the S-iPMSEL of M-point oscillation. The point P in the figure represents a reciprocal lattice point. Arrow B1 in the figure represents a basic reciprocal lattice vector, and arrows K1, K2, K3 and K4 represent four in-plane wave vectors. The in-plane wave vector K1 to K4 each have a wave number spreading SP due to the rotation angle distribution φ (x, y).

The shape and size of the wave number spreading SP are the same as in the case of the above-mentioned Γ point oscillation. In the M-point oscillation S-iPMSEL1, the magnitude of the in-plane wave vector K1 to K4 (that is, the magnitude of the standing wave in the in-plane direction) is smaller than the magnitude of the basic reciprocal lattice vector B1. Therefore, the vector sum of the in-plane wave vector K1 to K4 and the basic reciprocal lattice vector B1 cannot be 0, and the wave number in the in-plane direction cannot be 0 due to diffraction. No diffraction occurs. As it is, the S-iPMSEL1 of M point oscillation does not output the 0th-order light in the plane vertical direction (Z-axis direction), the 1st-order light in the direction inclined with respect to the Z-axis direction, and the -1st-order light.

In the present embodiment, by applying the following device to the phase modulation layer 15 in the S-iPMSEL1 of M point oscillation, a part of the primary light and the -1st order light is output without outputting the 0th order light. Can be made to. Specifically, as shown in FIG. 9, at least one of the in-plane wave vectors K1 to K4 is added by adding the diffraction vector V having a certain magnitude and direction to the in-plane wave vector K1 to K4. The magnitude of one (in-plane wave vector K3 in the figure) is made smaller than 2π / λ. In other words, at least one of the in-plane wave vectors K1 to K4 (in-plane wave vector K3) after the diffraction vector V is added is housed in the circular region (light line) LL having a radius of 2π / λ.

In-plane wave vector K1 to K4 shown by a broken line in FIG. 9 represent before addition of the diffraction vector V, and in-plane wave vector K1 to K4 shown by a solid line represent after addition of the diffraction vector V. .. The light line LL corresponds to the total reflection condition, and the wave vector having a size within the light line LL has a component in the plane vertical direction (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, and is 2π / (√2) a as an example. There is.

波数ベクトルの広がりΔｋｘ及びΔｋｙは、下記の数式（１２）及び（１３）をそれぞれ満たす。面内波数ベクトルのｘ軸方向の広がりの最大値Δｋｘｍａｘ及びｙ軸方向の広がりの最大値Δｋｙｍａｘは、設計の光像の角度広がりにより規定される。

Subsequently, the magnitude and direction of the diffraction vector V for accommodating at least one of the in-plane wave vector K1 to K4 in the light line LL will be examined. The following mathematical formulas (8) to (11) show in-plane wave vector K1 to K4 before the diffraction vector V is added.

The wave vector spreads Δkx and Δky satisfy the following equations (12) and (13), respectively. The maximum value Δkxmax of the spread in the x-axis direction and the maximum value Δkymax of the spread in the y-axis direction of the in-plane wave vector are defined by the angular spread of the optical image of the design.

When the diffraction vector V is expressed by the following mathematical formula (14), the in-plane wave vector K1 to K4 after the diffraction vector V is added becomes the following mathematical formulas (15) to (18).

すなわち、数式（１９）を満たす回折ベクトルＶを加えることにより、波数ベクトルＫ１～Ｋ４のいずれかがライトラインＬＬ内に収まり、１次光及び－１次光の一部が出力される。 Considering that any of the wave vector K1 to K4 fits within the light line LL in the formulas (15) to (18), the following relation of the formula (19) is established.

That is, by adding the diffraction vector V satisfying the equation (19), any of the wave vector K1 to K4 is contained in the light line LL, and a part of the primary light and the -1st order light is output.

The size (radius) of the light line LL is set to 2π / λ for the following reasons. FIG. 10 is a diagram for schematically explaining the peripheral structure of the light line LL. The figure shows the boundary between the device and air as seen from the direction perpendicular to the Z-axis direction. The magnitude of the wave vector of light in vacuum is 2π / λ, but when light propagates in the device medium as shown in FIG. 10, the magnitude of the wave vector Ka in the medium having a refractive index n is 2πn / λ. Will be. At this time, in order for light to propagate along the boundary between the device and air, the wavenumber component parallel to the boundary must be continuous (wavenumber conservation law).

In FIG. 10, when the wave vector Ka and the Z axis form an angle θ, the length of the wave vector (that is, the in-plane wave vector) Kb projected in the plane is (2πn / λ) sin θ. On the other hand, in general, due to the relationship of the refractive index n> 1 of the medium, the wavenumber conservation law does not hold at an angle where the in-plane wave vector Kb in the medium becomes larger than 2π / λ. At this time, the light is totally reflected and cannot be taken out to the air side. The magnitude of the wave vector corresponding to this total reflection condition is the magnitude of the light line LL, that is, 2π / λ.

As an example of a specific method of adding the diffraction vector V to the in-plane wave vector K1 to K4, light is applied to the rotation angle distribution φ1 (x, y) (first phase distribution) which is the phase distribution according to the optical image. A method of superimposing a rotation angle distribution φ2 (x, y) (second phase distribution) unrelated to the image can be considered. 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). φ1 (x, y) corresponds to the phase of the complex amplitude when the optical image is Fourier transformed as described above. Further, φ2 (x, y) is a rotation angle distribution for adding a diffraction vector V satisfying the above equation (19).

FIG. 11 is a diagram conceptually showing an example of the rotation angle distribution φ2 (x, y). In the example of the figure, the first phase value φA and the second phase value φB having a value different 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 change by π. With such an array of phase values, a diffraction vector V along the Γ-M1 axis or the Γ-M2 axis can be suitably realized. In the case of the checkered pattern arrangement, V = (± π / a, ± π / a), and the diffraction vector V and the wave vector K1 to K4 in FIG. 8 are just canceled out. 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.

In the above embodiment, when the wavenumber spread based on the angular spread of the light image is included in a circle having a radius Δk centered on a certain point in the wavenumber space, it can be simply considered as follows. By adding the diffraction vector V to the in-plane wave vector K1 to K4 in the four directions, the magnitude of at least one of the in-plane wave vectors K1 to K4 in the four directions is made smaller than 2π / λ (light line LL). This means that by adding the diffraction vector V to the wave vector K1 to K4 in the four directions minus the wave number spread Δk, the magnitude of at least one of the wave vectors K1 to K4 in the four directions is large. Can be considered to be smaller than the value {(2π / λ) −Δk} obtained by subtracting the wavenumber spread Δk from 2π / λ.

FIG. 12 is a diagram conceptually showing the above state. As shown in the figure, when the diffraction vector V is added to the in-plane wave vector K1 to K4 excluding the wave number spread Δk, the magnitude of at least one of the in-plane wave vectors K1 to K4 becomes {(2π / λ). ) -Δk}. In FIG. 12, the region LL2 is a circular region having a radius of {(2π / λ) −Δk}. In FIG. 12, the in-plane wave vector K1 to K4 shown by the broken line represents before the addition of the diffraction vector V, and the in-plane wave vector K1 to K4 shown by the solid line represent after the addition of the diffraction vector V. There is. The region LL2 corresponds to the total reflection condition in consideration of the wavenumber spread Δk, and the wave vector having a size within the region LL2 also propagates in the plane vertical direction (Z-axis direction).

In this embodiment, the magnitude and direction of the diffraction vector V for accommodating at least one of the in-plane wave vector K1 to K4 in the region LL2 will be described. The following mathematical formulas (20) to (23) show in-plane wave vector K1 to K4 before the diffraction vector V is added.

Here, when the diffraction vector V is expressed by the above-mentioned mathematical formula (14), the in-plane wave vector K1 to K4 after the diffraction vector V is added becomes the following mathematical formulas (24) to (27). ..

Considering that any of the in-plane wave vectors K1 to K4 fits in the region LL2 in the equations (24) to (27), the following equation (28) is established. That is, by adding the diffraction vector V satisfying the equation (28), any one of the in-plane wave vector K1 to K4 excluding the wave number spreading Δk is contained in the region LL2. Even in such a case, it is possible to output a part of the primary light and the -1st order light without outputting the 0th order light.

FIG. 13 is a plan view of the phase modulation layer according to the modified example. Further, FIG. 14 is a diagram showing the positional relationship of the different refractive index regions in the phase modulation layer according to the modified example. As shown in FIGS. 13 and 14, the center of gravity G of each different refractive index region 15b of the phase modulation layer 15 according to the modified example is arranged on the straight line D. The straight line D is a straight line that passes through the grid points O corresponding to each unit constituent region R and is inclined with respect to each side of the square grid. That is, the straight line D is a straight line inclined with respect 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.

The tilt angle θ is constant in the phase modulation layer 15B. The inclination angle θ satisfies 0 ° <θ <90 °, and in one example, θ = 45 °. Alternatively, the inclination angle θ satisfies 180 ° <θ <270 °, and in one example, θ = 225 °. When the tilt angle θ satisfies 0 ° <θ <90 ° or 180 ° <θ <270 °, the straight line D extends from the first quadrant to the third quadrant of the coordinate plane defined by the X-axis and the Y-axis. The inclination angle θ satisfies 90 ° <θ <180 °, and in one example, θ = 135 °. Alternatively, the inclination angle θ satisfies 270 ° <θ <360 °, and in one example, θ = 315 °. When the tilt angle θ satisfies 90 ° <θ <180 ° or 270 ° <θ <360 °, the straight line D extends from the second quadrant to the fourth quadrant of the coordinate plane defined by the X-axis and the Y-axis. As described above, the inclination angle θ is an angle excluding 0 °, 90 °, 180 ° and 270 °.

Here, the distance between the grid point O and the center of gravity G is r (x, y). x is the position of the x-th grid point on the X-axis, and y is the position of the y-th grid point on the Y-axis. When the distance r (x, y) is a positive value, the center of gravity G is located in the first quadrant (or the second quadrant). When the distance r (x, y) is a negative value, the center of gravity G is located in the third quadrant (or the fourth quadrant). When the distance r (x, y) is 0, the grid point O and the center of gravity G coincide with each other. The inclination angle is preferably 45 °, 135 °, 225 °, 275 °. At these tilt angles, only two of the four wave vectors (eg, in-plane wave vectors (± π / a, ± π / a)) that form the standing wave at point M are phase-modulated, and the others. Since the two are not phase-modulated, a stable standing wave can be formed.

The distance r (x, y) between the center of gravity G of each different refractive index region and the lattice point O corresponding to each unit constituent region R is individually set for each different refractive index region 15b according to the phase pattern corresponding to the desired optical image. Is set to. The phase pattern, that is, the distribution of the distance r (x, y) has a specific value for each position determined by the value of x, y, but is not always represented by a specific function. The distribution of the distance r (x, y) is determined from the complex amplitude distribution obtained by inverse Fourier transforming the desired optical image from which the phase distribution is extracted.

That is, as shown in FIG. 14, when the phase P (x, y) at a certain coordinate (x, y) is P ₀ , the distance r (x, y) is set to 0, and the phase P ( When x, y) is π + P ₀ , the distance r (x, y) is set to the maximum value R ₀ , and when the phase P (x, y) is −π + P ₀ , the distance r (x, y) is set. , Y) is set to the minimum value -R ₀ . Then, for the intermediate phase P (x, y), the distance r (x, y) is such that r (x, y) = {P (x, y) −P ₀ } × R ₀ / π. ). The initial phase P ₀ can be set arbitrarily.

Assuming that the lattice spacing of the virtual square lattice is a, the maximum value R ₀ of r (x, y) is, for example, within the range of the following equation (29). When determining the complex amplitude distribution from a desired optical image, the reproducibility of the beam pattern is improved by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method commonly used when calculating hologram generation. It is possible.

In this embodiment, a desired optical image can be obtained by determining the distribution of the distance r (x, y) in the different refractive index region 15b of the phase modulation layer 15. Under the same first to fourth preconditions as in the above-described embodiment, the phase modulation layer 15 is configured to satisfy the following conditions. That is, the distance r (x, y) from the lattice point O (x, y) to the center of gravity G of the corresponding different refractive index region 15b is.
r (x, y) = C × (P (x, y) -P ₀ )
C: Proportional constant, for example R ₀ / π
P ₀ : An arbitrary constant, for example, 0
The corresponding different refractive index regions 15b are arranged in the unit constituent region R (x, y) so as to satisfy the above relationship.

That is, the distance r (x, y) is set to 0 when the phase P (x, y) at a certain coordinate (x, y) is P ₀ , and the phase P (x, y) is π + P ₀ . If is, the maximum value is set to R ₀ , and if the phase P (x, y) is −π + P ₀ , the minimum value is set to −R ₀ . When a desired optical image is desired, the optical image is subjected to inverse Fourier transform, and the distribution of the distance r (x, y) corresponding to the phase P (x, y) of the complex amplitude is distributed in a plurality of different refractive index regions 15b. It is good to give it to. The phase P (x, y) and the distance r (x, y) may be proportional to each other.

Also in this embodiment, similarly to the above-described embodiment, the lattice spacing a of the virtual square lattice and the emission wavelength λ of the active layer 12 satisfy the condition of M-point oscillation. Further, when considering the reciprocal lattice space in the phase modulation layer 15, the magnitude of at least one of the wave vector in the four directions including the wave number spread due to the distribution of the distance r (x, y) is 2π / λ (light). Can be smaller than the line).

In this embodiment, the phase modulation layer 15 is devised as follows in the S-iPMSEL1 oscillating at the M point, so that the 0th-order light is not output in the light line, and the 1st-order light and the -1st-order light are not output. Output a part of. Specifically, as shown in FIG. 9, by adding a diffraction vector V having a certain magnitude and direction to the in-plane wave vector K1 to K4, at least one of the in-plane wave vectors K1 to K4 is added. Make one size smaller than 2π / λ. That is, at least one of the in-plane wave vector K1 to K4 after the diffraction vector V is added is housed in the circular region (light line) LL having a radius of 2π / λ. By adding the diffraction vector V satisfying the above-mentioned equation (19), any one of the in-plane wave vector K1 to K4 is contained in the light line LL, and a part of the primary light and the -1st order light is output.

Alternatively, as shown in FIG. 12, the wave vector K1 to K4 in four directions minus the wave number spread Δk (that is, the in-plane wave vector in four directions in the square grid PCSEL of M point oscillation) is diffracted. By adding the vector V, at least one of the wave vector K1 to K4 in the four directions is made smaller than the value {(2π / λ) −Δk} obtained by subtracting the wavenumber expansion Δk from 2π / λ. May be good. That is, by adding the diffraction vector V satisfying the above-mentioned mathematical formula (28), any one of the in-plane wave vector K1 to K4 is contained in the region LL2, and a part of the primary light and the -1st order light is output. ..

As an example of a specific method of adding the diffraction vector V to the in-plane wave vector K1 to K4, the optical image is obtained with respect to the distance distribution r1 (x, y) (first phase distribution) which is the phase distribution according to the optical image. A method of superimposing a distance distribution r2 (x, y) (second phase distribution) unrelated to the above can be considered. In this case, the distance distribution r (x, y) of the phase modulation layer 15 is
r (x, y) = r1 (x, y) + r2 (x, y)
It is expressed as. As described above, r1 (x, y) corresponds to the phase of the complex amplitude when the optical image is Fourier transformed. r2 (x, y) is a distance distribution for adding a diffraction vector V that satisfies the above formula (19) or formula (28). A specific example of the distance distribution r2 (x, y) is the same as in FIG.
[First Embodiment of 3D Measuring Device]

FIG. 15 is a schematic diagram showing the configuration of the three-dimensional measuring device 101A according to the first embodiment. As shown in the figure, the three-dimensional measuring device 101A includes a single light source unit 102, a plurality (pair) of imaging units 103, and a measuring unit 104. The light source unit 102 is configured by the above-mentioned M point oscillation S-iPMSEL1. The measurement light 105 emitted from the light source unit 102 irradiates a certain region on the surface of the object to be measured SA placed on the stage 106. The stage 106 may be a scanning stage capable of scanning in a two-dimensional direction or a three-dimensional direction. If the irradiation range of the measurement light 105 is sufficiently wider than the measurement range of the object to be measured SA, the arrangement of the stage 106 may be omitted.

In the present embodiment, the predetermined pattern of the measurement light 105 is a periodic pattern W1 including any one of a dot pattern, a stripe pattern, and a grid pattern. In the example of FIG. 16, the periodic pattern W1 of the measurement light 105 is a periodic dot pattern shown in an image area of 100 × 100 pixels. In this dot pattern, dots are arranged in a matrix, and the dot period is 5 pixels in both vertical and horizontal directions. Further, FIG. 17 is a diagram showing an example of a far-field image of a periodic pattern. 17 (a) is 40 × 40 dots, FIG. 17 (b) is 60 × 60 dots, FIG. 17 (c) is 80 × 80 dots, and FIG. 17 (d) is 120 × 120 dots. It is a statue. The driving conditions of the light source unit 102 are a current of 0.5 A, a pulse width of 50 ns, a pulse interval of 5 μs, and a temperature of 25 ° C. The center of the figure is the center of the measurement light 105 in the direction perpendicular to the plane, and the scale bar in the figure corresponds to 15 °. The far-field images shown in these figures are designed so that the dots are arranged in a matrix on a flat screen, and the distortion of the arrangement of the part away from the center is due to the optical system of the measurement system. be.

The image pickup unit 103 is configured by a device having sensitivity to the measurement light 105 emitted from the light source unit 102. As the image pickup unit 103, for example, a CCD (Charge Coupled Device) camera, a CMOS (ComplementaryMOS) camera, another two-dimensional image sensor, or the like can be used. The image pickup unit 103 takes an image of the object SA to be measured in a state of being irradiated with the measurement light 105, and outputs an output signal indicating the image pickup result to the measurement unit 104.

The measuring unit 104 is configured by a computer system including, for example, a processor, a memory, and the like. The measurement unit 104 executes various control functions by the processor. Examples of computer systems include personal computers, microcomputers, cloud servers, smart devices (smartphones, tablet terminals, etc.) and the like. The measurement unit 104 may be configured by a PLC (programmable logic controller) or an integrated circuit such as an FPGA (Field-programmable gate array).

The measurement unit 104 is communicably connected to the image pickup unit 103, and measures the three-dimensional shape of the object to be measured SA based on the output signal input from the image pickup unit 103. In the present embodiment, the measuring unit 104 measures the three-dimensional shape of the object to be measured SA based on the active stereo method using the periodic pattern W1. Here, as an example, a three-dimensional shape measurement method based on the principle of parallel coordinate stereo is shown. The parallax due to the pair of image pickup units 103, 103 is D, the distance between the pair of image pickup units 103, 103 is b, the focal length of the pair of image pickup units 103, 103 is f, and the object to be measured is from the pair of image pickup units 103, 103. Assuming that the distance to SA is Z, the parallax D is given by D = (f / Z) b. Since the distance b between the image pickup units 103 and 103 and the focal length of the image pickup units 103 and 103 are both unique values, the distance Z to the object to be measured SA can be obtained by obtaining the parallax D.

In the present embodiment, the measurement light 105 having the periodic pattern W1 is applied to the object to be measured SA. At this time, the measurement unit 104 can determine the same point of the periodic pattern W1 imaged by each of the image pickup units 103 and 103. In addition, it becomes possible to perform three-dimensional measurement using an image with few textures and three-dimensional measurement in a dark part, which has been a problem in the passive stereo method. By using the periodic pattern W1 represented by the periodic dots, it is possible to suppress the deviation of the pattern density of the measurement light 105 and suppress the unevenness of the measurement accuracy depending on the illumination position of the measurement light 105.

In the present embodiment, for example, a random dot pattern W2 as shown in FIG. 18 may be used instead of the periodic pattern W1. The random dot pattern W2 sets each dot of the dot pattern shown in FIG. 16 in the range from the position of the lattice point to the basic period region (a rectangular area surrounded by a line segment perpendicular to the midpoint between adjacent lattice points). The pattern is two-dimensionally randomly shifted. As an example, a random number φ (ix, ii) may be assigned to each dot located at the grid point, and each dot may be shifted from the position of the grid point based on the random number φ.

In this case, since the random dot pattern W2 has a pseudo periodicity, the deviation of the pattern density of the measurement light 105 is suppressed, and it is possible to suppress the unevenness of the measurement accuracy depending on the illumination position of the measurement light 105. .. Further, by using the random dot pattern W2 instead of the periodic dot pattern, it is possible to suppress erroneous recognition when the same point of the dot pattern is imaged by different imaging units 103. Therefore, the measurement accuracy of the parallax D can be improved, and the accuracy of the three-dimensional shape measurement can be improved.

Further, in the present embodiment, instead of the periodic pattern W1, a pattern W3 having a uniform density as shown in FIG. 19 may be used. Since the light emitted from the S-iPMSEL1 is a laser light, speckles may occur in the scattered light. In addition, unintended speckle-like noise may be mixed in the phase calculation. Therefore, even when the pattern W3 having a uniform density is used, a random dot pattern is formed in the pattern of the measurement light 105. By using this random dot pattern, it is possible to suppress erroneous recognition when the same point of the dot pattern is imaged by different imaging units 103.

FIG. 20 is a diagram showing an example of an FFP (Far Field Pattern) of a pattern W3 having a uniform density. In the example of the figure, the pulse width of the measurement light 105 is 50 ns, the repetition interval is 5 μs, and FFP is observed at room temperature. In addition, color tone correction of brightness + 40% and contrast -40% is added. In the figure, it can be confirmed that a random dot pattern is formed in the pattern of the measurement light 105 even when the pattern W3 having a uniform density is used.

In the example of FIG. 15, the three-dimensional measuring device 101A includes a single light source unit 102, but the three-dimensional measuring device 101A may include a plurality of light source units 102. In this case, by irradiating different regions of the object to be measured SA with the measurement light 105 from each light source unit 102, the measurement region can be expanded without scanning the stage 106. When adopting this configuration, the arrangement of the stage 106 may be omitted.
[Second Embodiment of 3D Measuring Device]

FIG. 21 is a schematic diagram showing the configuration of the three-dimensional measuring device according to the second embodiment. As shown in the figure, the three-dimensional measuring device 101B according to the second embodiment includes a plurality of light source units 102, a single image pickup unit 103, and a measuring unit 104. The configuration of the image pickup unit 103, the light source unit 102, and the measurement unit 104 is the same as that of the first embodiment. In the present embodiment, the predetermined pattern of the measurement light 105 is a Gray code pattern, and the measurement unit 104 measures the three-dimensional shape of the object to be measured SA based on the triangulation method using the Gray code pattern.

FIG. 22 is a diagram showing an example of a Gray code pattern. In the example of the figure, the pixels of the imaging unit 103 are Nx × Ny, and the X direction is shown. Assuming that the pixel position n in the X direction (n is an integer from 0 to Nx-1) is a binary number of Mx digits, the Gray code pattern W4 expresses the binary number of the target number and the binary number of the target number. It is represented by an exclusive logical sum with a number shifted to the right by 1 bit and prefixed with 0. That is, assuming that the number of objects is n, the Gray code pattern W4 is given by a logical expression of n ^ (n >> 1). In the example of FIG. 22, the gray code patterns W4a to W4d in the case of 4 bits (4 patterns) are shown. For example, OpenCV or the like can be used to generate the Gray code pattern W4.

In Gray code, the Hamming distance of adjacent pixels is 1. The Hamming distance refers to the number of digits of different values at the corresponding positions when comparing two values with the same number of digits. Therefore, in the Gray code where the Hamming distance is 1, the error is within 1 even if a bit error occurs when restoring the bit string. In simple binary code, the position error becomes large when an error occurs in the high-order bit, but in Gray code, a code that is resistant to noise can be obtained.

When the Gray code is used, the number of arrangements of the light source unit 102 may be any number of patterns corresponding to each digit of the binary number. That is, the gray code patterns W4a to W4d are composed of a plurality of striped patterns in which 0 and 1 of each pixel of each digit from the most significant bit to the least significant bit are set to be different from each other. When image pickup is performed by the image pickup unit 103 while sequentially switching each pattern from the gray code pattern W4a of the most significant bit to the gray code pattern W4d of the least significant bit in the light source unit 102, the value X is obtained by imaging Mx times. It can be seen that the position of the Xth pixel is measured based on this value X. Similarly, in the Y direction, the value Y can be obtained by imaging My times by performing imaging with the imaging unit 103 while sequentially switching the gray code patterns W4a to W4d. It can be seen that the position of the Yth pixel is measured based on this value Y.

In order to avoid erroneous recognition due to the color of the surface of the object to be measured SA, the gray code patterns W4a to W4d shown in FIG. 22 may be used in combination with the gray code pattern in which black and white are reversed. In this case, the number of arrangements of the light source units 102 may be 2Mx + 2My.

In the present embodiment, instead of the Gray code pattern W4, for example, as shown in FIG. 23, a sinusoidal stripe pattern W5 may be used. The sinusoidal stripe pattern W5 shown in FIG. 23 is a periodic stripe pattern shown in an image area of 100 × 100 pixels. The period of the sinusoidal stripe pattern W5 is a period of 20 pixels. The measuring unit 104 measures the three-dimensional shape of the object to be measured SA based on the phase shift method using the sinusoidal stripe pattern W5. In this embodiment, for example, a plurality of sinusoidal stripe patterns W5 in which a phase shift (positional shift) obtained by equally dividing one cycle with respect to the lattice pitch is given are used. The phase shift pattern may be prepared so that the phases are shifted by 2π / N (N is an integer).

Here, the case of using four sinusoidal stripe patterns W5 having different phase shifts will be illustrated. Assuming that the light intensities of the measurement light 105 having the sinusoidal stripe pattern W5 of 4 are I0 to I3 and the pixels of the image pickup unit 103 are (x, y), the light intensities I0 to I3 on the surface of the object to be measured SA are set to (x, y). Is represented 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.

The initial phase θ can be obtained by tan θ = − (I3-I1) / (I2-I0). When the number of phase shifts of the sinusoidal stripe pattern W5 is N, the initial phase θ can be obtained by the following equation (34).

When such a phase shift method is used, the height of the object to be measured SA can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern W5 by converting the measured phase into height. In the configuration of the three-dimensional measuring device 101B, the light source units 102 may be arranged in a direction parallel to the stripes in the sinusoidal stripe pattern W5. In this case, it is possible to eliminate the phase shift caused by the positional shift of the light source unit 102, and it is possible to eliminate the initial phase shift in each of the plurality of sinusoidal stripe patterns W5.

In the present embodiment, the light source units 102 may be arranged in biaxial directions orthogonal to each other. In this case, the height profile of the object to be measured SA can be acquired on two axes by switching the measurement light 105 on and off for each axis. Further, instead of the sine and cosine pattern W5, for example, as shown in FIG. 24, a matrix pattern W6 that changes in a sine and cosine shape in two axial directions orthogonal to each other may be used. When such a matrix pattern W6 is used, the height profile of the object to be measured SA can be measured simultaneously in the biaxial directions.

In the present embodiment, the plurality of light source units 102 may output sinusoidal stripe patterns W5 having different periods from each other. In the phase shift method described above, the discontinuity at the phase 2π is a problem. On the other hand, when the sinusoidal stripe patterns W5 having different periods are used, for example, as shown in FIG. 25, the discontinuity in the phase 2π is improved by selecting the coordinates that match at all frequencies. This makes it possible to realize highly accurate 3D measurement with a small number of patterns. By improving the discontinuity in the phase 2π, it is possible to expand the measurement range of the three-dimensional shape measurement and realize highly accurate measurement of the measured object SA having remarkable unevenness.

In the present embodiment, the measuring unit 104 may measure the three-dimensional shape of the object to be measured SA based on the sampling moire method using the sinusoidal stripe pattern W5. The sampling moiré method utilizes the fact that the grid of the sinusoidal stripe pattern W5 projected on the surface of the object to be measured SA is deformed according to the height of the object to be measured SA. Here, in the image captured by the image pickup unit 103, the fringe interval of one sine wave pattern having the phase shift number N at the height of the reference plane is adjusted in advance so as to correspond to the N pixels of the camera. Here, the phase shift number N is set to 4. By irradiating one sine wave pattern and sampling the pixels of the imaging unit 103 every 4 pixels, images were taken every 4 pixels (3 pixels between the imaging pixels) as shown in FIG. 26 (a). 4 patterns P1 to P4 (thinned out) are obtained. Between these patterns P1 to P4, the image pickup pixels are shifted one by one, and by linearly interpolating the luminance values of the image pickup pixels, as shown in FIG. 26 (b), the moire fringe patterns whose phases are shifted from each other. M1 to M4 are obtained. By applying the above-mentioned phase shift method using these moire fringe patterns M1 to M4, the height of the object to be measured SA can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern W5. According to such a method, the number of sine wave patterns to be irradiated can be reduced as compared with the above-mentioned phase shift method, and the light source unit 102 can be made compact.

In the present embodiment, instead of the sinusoidal stripe pattern W5, for example, as shown in FIG. 27, a superimposition pattern W7 in which the sinusoidal stripe pattern W5 and the random dot pattern W2 are superimposed may be used. By using such a superposed pattern W7, the height of the object to be measured SA can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern W5. Further, by combining random dot patterns, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns. As shown in FIG. 28, the superimposition pattern may be a superimposition pattern W8 in which a matrix pattern W6 that changes in a sinusoidal shape and a random dot pattern W2 are superposed. In this case, in addition to the above-mentioned effect, the height profile of the object to be measured SA can be measured simultaneously in the biaxial directions.

In this embodiment, both the sinusoidal stripe pattern W5 and the Gray code pattern W4 may be used. In this case, the measuring unit 104 measures the three-dimensional shape of the object to be measured SA based on the phase shift method using the sinusoidal stripe pattern W5 and the triangulation method using the Gray code pattern W4. In this case, the pixel level measurement can be performed by the triangulation method using the Gray code pattern W4, and the subpixel level measurement can be performed by the phase shift method using the sinusoidal stripe pattern W5. Further, by using the Gray code, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns.
[Third Embodiment of a three-dimensional measuring device]

FIG. 29 is a schematic diagram showing the configuration of the three-dimensional measuring device according to the third embodiment. As shown in the figure, the three-dimensional measuring device 101C according to the third embodiment includes a plurality of light source units 102, a plurality of (pair) imaging units 103, and a measuring unit 104. The configuration of the image pickup unit 103, the light source unit 102, and the measurement unit 104 is the same as that of the first embodiment. In the present embodiment, the predetermined pattern of the measurement light 105 is a sinusoidal stripe pattern W5, and the measurement unit 104 is based on the phase shift method and the active stereo method using the sinusoidal stripe pattern W5. Measure the three-dimensional shape of.

In the present embodiment, the height of the object to be measured SA can be measured at intervals smaller than the pitch of the sinusoidal stripe pattern W5 by converting the measured phase into height. Further, by combining the active stereo method using a plurality of image pickup units 103, it is possible to improve the discontinuity in the phase 2π, and it is possible to realize highly accurate three-dimensional measurement with a small number of patterns. When the active stereo method is used, the above-mentioned dot pattern may be switched and used.
[Phase shift of sinusoidal stripe pattern by S-iPMSEL]

In S-iPMSEL1, in addition to the designed primary light, -1st order light symmetrical with respect to the normal of the emission surface is output (see FIG. 6). Therefore, when the phase shift of the sine wave-shaped stripe pattern W5 is performed, the direction in which the stripe shifts between the primary light and the -1st light is reversed when considering the sine wave in which the ± primary light overlaps. The pattern may deviate from the design. For the sake of simplicity, considering the shift of the stripe in the X-axis direction, the complex amplitude of the primary light is expressed by the following equation (35). The complex amplitude of the -1st order light is emitted at a position symmetrical to the 1st order light with respect to the surface normal, and is expressed by the following equation (36). In the equation, k (= kx, ky, kz) is the wavenumber vector (magnitude 2π / λ), λ is the wavelength, ω is each frequency of light, Δθ is the phase shift, and a1 is the primary light amplitude (ideal phase). For the distribution, K is the wave number of the sine wave fringe (= 2π / Λ (Λ is the period of the sine wave)), θ is the phase shift amount of the sine wave, ( x, y, z) are the coordinates of the projected beam.

実際の光強度は、合成振幅Ａの二乗に比例するため、下記式（３８）により求めることができる。

基本光波の周期は、正弦波の周期に比べて十分に小さい（λ＜＜Λ）。したがって、基本光波の波数ｋは、正弦波の縞の波数Ｋに比べて十分に大きい（ｋ＞＞Ｋ）。このため、上記式（３８）において、ｋの変化に対応する項を平均化してもよいと考えられる。この場合、±１次光を重畳した光の強度Ｉは、下記式（３９）により近似できる。

At this time, the combined amplitude A can be obtained by the following equation (37) based on the amplitudes of the primary light and the -1st order light.

Since the actual light intensity is proportional to the square of the combined amplitude A, it can be obtained by the following equation (38).

The period of the fundamental light wave is sufficiently smaller than the period of the sine wave (λ << Λ). Therefore, the wave number k of the fundamental light wave is sufficiently larger than the wave number K of the sine wave stripe (k >> K). Therefore, in the above equation (38), it is considered that the terms corresponding to the changes in k may be averaged. In this case, the intensity I of the light on which ± primary light is superimposed can be approximated by the following equation (39).

From these equations, it can be seen that when the phase shift of the sinusoidal stripe pattern W5 is performed, the stripes shift while maintaining the sinusoidal shape even if the ± primary light overlaps. In addition, in the sine wave pattern in which ± primary light is superimposed, the interval between the stripes of the light intensity (the square of the sum of the amplitudes of ± primary light) actually obtained is halved with respect to the design pattern (primary light amplitude). It can be seen that the phase shift amount is doubled for one cycle. Therefore, for example, when a phase shift of π / 2 is realized in the finally obtained light intensity, the design value of the phase shift amount of the primary light amplitude may be set to π / 4. The same applies to the sinusoidal matrix pattern W6 having a period in the biaxial direction.

As shown in FIG. 4, when the center of gravity G of the different refractive index region 15b in S-iPMSEL1 is formed by shifting it in the circumferential direction around the lattice point O, the amplitudes a of the primary light and the -1st order light are set. The values are equal to each other. On the other hand, as shown in FIG. 14, when the center of gravity G of the different refractive index region 15b in S-iPMSEL1 is shifted on a straight line D that passes through the lattice point O and is inclined with respect to each side of the square lattice. The amplitudes a of the primary light and the -1st order light have different values from each other. In either case, a sine wave pattern in which ± primary light is superimposed can be used.

When the primary light and the -1st order light have an asymmetric pattern, there is a problem that the designed pattern cannot be obtained if the primary light and the -1st order light overlap. As an example of such a problem, the structure per bright spot of the primary light has an asymmetric spread, and the design pattern becomes unclear. In this case, the emission region of the primary light may be limited to the region where the solid angle is π. For example, when the emission region of the primary light is limited to the first quadrant and the second quadrant, the emission region of the -1st quadrant is the 4th quadrant and the 3rd quadrant. It is possible to avoid overlapping. As a result, it is possible to suppress the spread of bright spots due to the overlap of the primary light and the -1st order light. When the grid pattern is shifted by the phase shift method, the shift direction of the -1st order light is inverted with respect to the shift direction of the primary light. Therefore, it is preferable to invert the phase obtained by the phase shift operation according to the respective emission regions of the primary light and the -1st order light. On the other hand, even if the above problem does not occur, if an image with less noise can be obtained without superimposing the primary light and the -1st order light, use the ± primary light projection area without superimposing them. May be good.
[Example of arrangement of light source unit and image pickup unit]

FIG. 30 is a schematic perspective view showing an example of arrangement of the light source unit and the image pickup unit. As shown in FIG. 30, in constructing the three-dimensional measuring device 101, the light source unit 102 and the imaging unit 103 may be arranged on the surface of the three-dimensional object 111. The three-dimensional object 111 constitutes a portion corresponding to the probe of the three-dimensional measuring devices 101A to 101C. The three-dimensional object 111 is formed in a cylindrical shape by, for example, metal or resin. The three-dimensional object 111 may have rigidity or may have flexibility. The three-dimensional object 111 may have an internal space.

The light source unit 102 and the image pickup unit 103 are arranged on the peripheral surface 111a of the cylindrical three-dimensional object 111 at regular intervals (here, a phase angle of 45 °) in the circumferential direction. In the example of FIG. 30, one group of the image pickup unit 103, the group of the light source unit 102, and the other group of the image pickup unit 103 are arranged at regular intervals from the tip end side to the base end side of the three-dimensional object 111. When the three-dimensional object 111 is viewed from the longitudinal direction, one image pickup unit 103, a light source unit 102, and the other image pickup unit 103 are arranged in a row, and these sets form one measurement area for the object to be measured SA. There is. When the three-dimensional object 111 has an internal space, wiring or the like for the light source unit 102 and the image pickup unit 103 may be accommodated in the internal space. The arrangement interval between the light source unit 102 and the image pickup unit 103 does not necessarily have to be equal. Further, when the measurement range for the object to be measured SA is covered, the single light source unit 102 and the single image pickup unit 103 may be arranged on the three-dimensional object 111.

FIG. 31 is a schematic perspective view showing another arrangement example of the light source unit and the image pickup unit. In the example of FIG. 31, the three-dimensional object 121 has a spherical shape, and is provided, for example, at the tip end portion of the cylindrical support portion 122. The light source unit 102 and the image pickup unit 103 are arranged on the spherical surface 121a of the spherical three-dimensional object 121 at regular intervals (here, a phase angle of 45 °) in the longitude direction. The group of one image pickup unit 103, the group of light source units 102, and the group of the other image pickup unit 103 are arranged at regular intervals in the latitude direction of the three-dimensional object 121. A set of one image pickup unit 103, a light source unit 102, and the other image pickup unit 103 arranged in the longitude direction of the three-dimensional object 121 constitutes one measurement area for the object to be measured SA. When the three-dimensional object 121 has an internal space, wiring or the like for the light source unit 102 and the image pickup unit 103 may be accommodated in the internal space. As in the case of FIG. 30, the arrangement interval between the light source unit 102 and the image pickup unit 103 does not necessarily have to be equal. Further, when the measurement range for the object to be measured SA is covered, the single light source unit 102 and the single image pickup unit 103 may be arranged on the three-dimensional object 121.

According to the above configuration, the three-dimensional objects 111 and 121 in which the light source unit 102 and the image pickup unit 103 are arranged can be configured as a probe of the three-dimensional measuring device 101. By using such three-dimensional objects 111 and 121, each pair of the light source unit 102 and the image pickup unit 103 can be oriented in different directions, so that the three-dimensional shape measurement of the object to be measured SA is performed at a wide solid angle. It becomes possible to do. In addition, for example, it can be applied to applications such as oral examination, endoscopy, inspection of narrow places such as the inside of pipes and gaps in walls, inspection from under the floor of furniture and equipment, and construction of handy type 3D measuring equipment. It will be easy.

FIG. 23 shows a sine and cosine-shaped stripe pattern W5, but in forming such a stripe pattern, it is important to reduce noise (luminance fluctuation) between adjacent patterns. Noise between adjacent patterns may cause, for example, position fluctuation when applying the phase shift method, and may affect the measurement accuracy. Therefore, in order to realize the formation of a stripe pattern in consideration of noise reduction between adjacent patterns, for example, as shown in FIG. 32, the S-iPMSEL1 that emits a one-dimensional multipoint pattern and the one-dimensional lens 51 are used. A combination of configurations can be adopted.

In the example of FIG. 32, 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 surface 52a of the one-dimensional concave lens 52 is a flat surface, and the other surface 52b is a concave surface. The one-dimensional concave lens 52 is arranged with respect to the surface (laser light emitting surface) of the S-iPMSEL1 with one surface 52a facing the S-iPMSEL1. The one-dimensional concave lens 52 may 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 beam in the lens medium, and f is the focal length.

The multi-point pattern laser beam La from S-iPMSEL1 is arranged at predetermined intervals in the X direction in the examples of FIGS. 32 and 33 (a). In the example of FIG. 32, the one-dimensional concave lens 52 is arranged so that the concave surface extends in the X-axis direction. The laser beam La of the multipoint pattern that has passed through the one-dimensional concave lens 52 does not change in the X-axis direction and expands only in the Y-axis direction. Therefore, by passing the laser beam La of the multipoint pattern through the one-dimensional concave lens 52, as shown in FIG. 33B, the striped pattern W11 in which the line-shaped laser beam Lb extended in the Y direction is arranged in the X-axis direction is formed. can get.

When the stripe pattern is made closer to a sinusoidal shape, for example, as shown in FIG. 34 (a), a multipoint pattern laser beam La is formed, and the brightness of each laser beam is controlled to be sinusoidal in the X-axis direction. .. By passing the laser beam La of such a multi-point pattern through the one-dimensional concave lens 52, in the stripe pattern W12 shown in FIG. 34 (b), the line-shaped laser beam Lb extended in the Y direction is lined up in the X-axis direction. , The brightness of each laser beam Lb is changed in a sinusoidal manner in the X-axis direction.

In FIGS. 34 (a) and 35 (a), the laser beams La of the multipoint pattern are aligned in a straight line in the X-axis direction, but the laser light Las do not necessarily have to be aligned in a straight line. , May be periodically or randomly deviated in the Y-axis direction. The one-dimensional lens 51 is not limited to the one-dimensional concave lens 52 as long as it can expand the laser beam La of the multipoint pattern in the one-dimensional direction, and may be a Powell lens or a lineman lens that functions as a line generator. .. The one-dimensional lens 51 may be a flat lens such as a Fresnel lens, a micro lens, or a metal lens.

When a metal lens is used, for example, a resonance type metal lens structure 53A as shown in FIG. 35 (a) may be adopted, and for example, a refractive index modulation type metal lens structure 53B as shown in FIG. 35 (b) may be adopted. May be good. As shown in FIG. 35 (a), when the resonance type metal lens structure 53A is adopted, the constituent material of the metal lens structure 53A is a material having a higher refractive index than the underlying layer. For example, when the underlying layer (for example, the antireflection 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 cell constituting the metal lens structure 53A are set based on the lens phase obtained by the above-mentioned equation (40).

As shown in FIG. 35B, when the refractive index modulation type metal lens structure 53B is adopted, the metal lens structure 53B can be formed by etching the surface of S-iPMSEL1. For example, on the surface of S-iPMSEL1, a refractive index-modulated metal lens is formed by etching to form a hole 54 extending from the outermost layer (for example, the antireflection film 19) to the middle of the lower layer (for example, the semiconductor substrate 10). Structure 53B can be formed. The depth and diameter of each hole 54 constituting the metal lens structure 53B are set based on the lens phase obtained by the above equation (40).

1 ... S-iPMSEL, 101 (101A to 101C) ... 3D measuring device, 102 ... light source unit, 103 ... imaging unit, 104 ... measuring unit, 105 ... measured light, SA ... object to be measured, W1 ... periodic pattern, W2 ... Random dot pattern, W3 ... Pattern with uniform density, W4 ... Gray code pattern, W5, W6 ... Sine wave-shaped stripe pattern, W7, W8 ... Superimposition pattern, W11, W12 ... Sine wave-shaped stripe pattern, 111, 121 … Three-dimensional object.

Claims (12)

One or more light source units that irradiate the object to be measured with measurement light having a predetermined pattern,
One or more image pickup units that image the object to be measured irradiated with the measurement light, and
A measurement unit that measures the three-dimensional shape of the object to be measured based on the image pickup result by the image pickup unit is provided.
The light source unit is a three-dimensional measuring device configured by S-iPMSEL of M point oscillation. A single light source unit and a plurality of image pickup units are included.
The predetermined pattern of the measurement light is a periodic pattern including any one of a dot pattern, a stripe pattern, and a grid pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures the three-dimensional shape of the object to be measured based on the active stereo method using the periodic pattern. A single light source unit and a plurality of image pickup units are included.
The predetermined pattern of the measurement light is a random dot pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures a three-dimensional shape of the object to be measured based on an active stereo method using the random dot pattern. A single light source unit and a plurality of image pickup units are included.
The predetermined pattern of the measurement light is a pattern having a uniform density.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures a three-dimensional shape of the object to be measured based on an active stereo method using a pattern having a uniform density. A plurality of the light source units and a single image pickup unit are included.
The predetermined pattern of the measurement light is a Gray code pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures a three-dimensional shape of the object to be measured based on a triangulation method using the Gray code pattern. A plurality of the light source units and a single image pickup unit are included.
The predetermined pattern of the measurement light is a sinusoidal stripe pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures the three-dimensional shape of the object to be measured based on a phase shift method using the sinusoidal stripe pattern. The three-dimensional measuring device according to claim 6, wherein the plurality of light source units output sinusoidal stripe patterns having different periods from each other. A plurality of the light source units and a single image pickup unit are included.
The predetermined pattern of the measurement light is a sinusoidal stripe pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures a three-dimensional shape of the object to be measured based on a sampling moire method using the sinusoidal stripe pattern. A plurality of the light source units and a single image pickup unit are included.
The predetermined pattern of the measurement light is a superposition pattern in which a sinusoidal stripe pattern and a random dot pattern are superposed.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures the three-dimensional shape of the object to be measured based on a phase shift method using the superimposed pattern. A plurality of the light source units and a single image pickup unit are included.
The predetermined pattern of the measurement light includes a sinusoidal stripe pattern and a Gray code pattern.
The three-dimensional shape according to claim 1, wherein the measuring unit measures a three-dimensional shape of the object to be measured based on a phase shift method using the sinusoidal stripe pattern and a triangulation method using the Gray code pattern. Measuring device. A plurality of the light source units and the plurality of image pickup units are included.
The predetermined pattern of the measurement light is a sinusoidal stripe pattern.
The three-dimensional measuring device according to claim 1, wherein the measuring unit measures the three-dimensional shape of the object to be measured based on a phase shift method using a sinusoidal stripe pattern and an active stereo method. The three-dimensional measuring device according to any one of claims 1 to 11, wherein the light source unit and the image pickup unit are arranged on the surface of a three-dimensional object.

Images