Semiconductor light emitting device

Abstract

The semiconductor light-emitting device includes: a plurality of iPM lasers each having a first surface and a second surface facing the first surface and outputting light from the first surface; and a drive circuit that supplies a drive current for causing each of the plurality of iPM lasers to emit light. The drive circuit includes: a current source circuit common to the plurality of iPM lasers; a plurality of switching units that are provided corresponding to the plurality of iPM lasers, respectively, and that switch the ON / OFF of the drive current; and a switch operation unit for individually operating the plurality of switch units.

Description

Technical Field

[0001] One aspect of the present invention relates to a semiconductor light emitting device. Background Art

[0002] In a semiconductor light emitting device including a plurality of photonic crystal lasers, a driving circuit for driving each photonic crystal laser is known (for example, refer to non-patent document 1). In non-patent document 1, a driving circuit having a plurality of digital-to-analog converters, a plurality of operational amplifiers, and a plurality of transistors in a manner corresponding to a plurality of photonic crystal lasers is described. In the driving circuit described in non-patent document 1, a 12-bit digital control signal from a microcontroller is digitally converted to analog, and a transistor is driven to control the current flowing through the laser.

[0003] Patent document 1 discloses a shape measuring device. The shape measuring device includes three or more light sources arranged in a row for projecting a grid pattern. Non-patent document 3 discloses a three-dimensional shape measuring method using structured illumination. Non-patent document 1 also discloses a phase shift method using a fringe pattern.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-242178.

[0007] Non-patent literature

[0008] Non-patent document 1: "Study on beam shape control based on the in-plane mutual introduction phenomenon of photonic crystal lasers", Menaka De Zoysa et al., 81st Applied Physics Society Fall Academic Lecture Proceedings, 10p-Z18-8, 2020

[0009] Non-patent document 2: Y.Kurosaka et al., "Effects of non-lasing band in two-dimensional photonic-crystal lasers clarified using omnidirectional bandstructure," Opt.Express 20, 21773-21783 (2012)

[0010] Non-patent document 3: Jason Geng, “Structured-light 3D surface imaging: a tutorial,” Advances in Optics and Photonics 3, pp. 128-160 (2011) Summary of the invention

[0011] Problems to be solved by the invention

[0012] It is known that there is an iPM (integrable Phase Modulating) laser that outputs a desired light image through phase modulation in a phase modulation layer. A semiconductor light-emitting device including a plurality of iPM lasers can be applied to various purposes. For example, a light image of a periodic stripe pattern is output in sequence from each iPM laser, and the phases of the stripe patterns output from each iPM laser are staggered from each other, thereby being applicable to three-dimensional measurement. However, in the case where the drive circuit described in non-patent document 1 is applied to a semiconductor light-emitting device including a plurality of iPM lasers, there are the following problems. That is, a plurality of signal lines are required between a microcontroller and a digital-to-analog converter, and a plurality of digital-to-analog converters are provided in a manner corresponding to a plurality of iPM lasers, respectively. Therefore, the total number of signal lines becomes huge. In addition, since a plurality of operational amplifiers and a plurality of transistors are provided, the area of ​​the entire drive circuit may become large. In addition, a plurality of digital-to-analog converters, a plurality of operational amplifiers, and a plurality of transistors are provided corresponding to a plurality of iPM lasers, respectively. As a result, power consumption (standby power) is also generated in multiple digital-to-analog converters, multiple operational amplifiers, and multiple transistors corresponding to the iPM laser that is not driven, and there is a concern about heat generation associated with the standby power. Depending on the application of the semiconductor light-emitting device (for example, obtaining a three-dimensional image of the oral cavity in dentistry, etc.), it is required to reduce the heat generation and make the device miniaturized.

[0013] An object of one aspect of the present invention is to provide a semiconductor light emitting device capable of reducing heat generation and achieving miniaturization of the device.

[0014] Methods for solving problems

[0015] A semiconductor light emitting device according to one aspect of the present invention, [1] "comprises: a plurality of iPM lasers having a first surface and a second surface opposite to the first surface, and outputting light from the first surface; and a driving circuit for supplying a driving current for causing each of the plurality of iPM lasers to emit light, the driving circuit comprising: a current source circuit common to the plurality of iPM lasers; a plurality of switch units respectively provided corresponding to the plurality of iPM lasers and for switching the driving current on / off; and a switch operating unit for operating each of the plurality of switch units individually".

[0016] In the semiconductor light-emitting device described in [1] above, by using a switch action unit to operate a plurality of switch parts individually, it is possible to supply a driving current to each iPM laser corresponding to each of the plurality of switch parts. Assuming that a plurality of current source circuits corresponding to each iPM laser are provided, in the current source circuit corresponding to the iPM laser that is not driven, the current source circuit itself is also driven, so that power consumption (standby power) is generated. In the semiconductor light-emitting device described in [1] above, the driving current is supplied based on the current generated by the common current source circuit, so that the heat generated by the standby power can be reduced. In addition, since it is a common current source circuit, the number of current source circuits is small, so the miniaturization of the semiconductor light-emitting device can be achieved.

[0017] A semiconductor light-emitting device according to one aspect of the present invention may also be, [2] "In the semiconductor light-emitting device described in [1] above, each of the plurality of switch units has a first switch and a second switch connected in series with the first switch, and the switch action unit includes: a first shift register for actuating the first switch; and a second shift register for actuating the second switch." According to the semiconductor light-emitting device described in [2], a drive current can be supplied individually only to an iPM laser in which both the first switch and the second switch are turned on. Moreover, the first shift register can specify an iPM laser to be driven, for example, in units of rows, and the second shift register can specify an iPM laser to be driven, for example, in units of columns. Thus, it is easy to supply a drive current individually to a plurality of iPM lasers arranged in multiple rows and columns.

[0018] A semiconductor light emitting device [3] according to one aspect of the present invention may also be, "In the semiconductor light emitting device described in [1] or [2] above, the drive circuit further includes a plurality of current mirror circuits corresponding to the plurality of iPM lasers, each of the plurality of current mirror circuits including a first current path and a second current path, a current whose magnitude is proportional to the magnitude of the current flowing through the first current path flows through the second current path, the first current path is connected to the common current source circuit, the switch section is provided on the first current path, and the second current path is connected to the iPM laser corresponding to the current mirror circuit to which the second current path belongs among the plurality of iPM lasers". According to the semiconductor light emitting device described in [3], a drive current based on a current generated by the common current source circuit can be supplied to the iPM laser via the second current path.

[0019] The semiconductor light-emitting device of one aspect of the present invention may also be, [4] "In the semiconductor light-emitting device described in any one of [1] to [3] above, the drive circuit also has a plurality of oscillation prevention circuits corresponding to the plurality of iPM lasers respectively, and the plurality of oscillation prevention circuits each have: an NMOS-FET, which includes a source terminal connected to the anode terminal of each of the plurality of iPM lasers and a drain terminal connected to the first constant potential line; a first PMOS-FET, which includes a gate terminal connected to the source terminal of the NMOS-FET, and a drain terminal connected to a second constant potential line having a potential lower than the first constant potential line; and a second PMOS-FET, which includes a drain terminal connected to the source terminal of the first PMOS-FET, a source terminal connected to a third constant potential line having a potential higher than the second constant potential line, and a gate terminal for supplying current to the first PMOS-FET according to an input voltage to the gate terminal, and the potential between the first PMOS-FET and the second PMOS-FET is supplied to the gate terminal of the NMOS-FET." According to the semiconductor light emitting device described in [4], the resonance constant (Q value) can be reduced by providing an oscillation prevention circuit, thereby suppressing ringing and peaking and performing stable driving of the iPM laser.

[0020] The semiconductor light emitting device according to one aspect of the present invention may be [5] "In the semiconductor light emitting device described in any one of [1] to [4] above, the value of the current generated by the common current source circuit is variable." According to the semiconductor light emitting device described in [5], the magnitude of the driving current is variable, so that the amount of light from each iPM laser is changed, and as a result, the brightness of the light images output from the plurality of iPM lasers can be changed.

[0021] The semiconductor light-emitting device of one aspect of the present invention may also be, [6] "In the semiconductor light-emitting device described in [5] above, the common current source circuit further comprises: an operational amplifier that supplies an input voltage to one of a pair of input terminals; a transistor having a control terminal connected to the output terminal of the operational amplifier; and a resistor section, one end of which is connected to the current terminal of the transistor and the other input terminal of the operational amplifier, and the other end is connected to a fourth constant potential line, the resistance value of the resistor section is variable, and the switching action of the plurality of switch sections is synchronized with the action of changing the resistance value of the resistor section." According to the semiconductor light-emitting device described in [6], the resistance value of the resistor section is variable, thereby changing the current value generated by the current source circuit. Furthermore, by synchronizing the switching action of the plurality of switch sections with the action of changing the resistance value of the resistor section, the value of the drive current supplied to each iPM laser can be set for each iPM laser.

[0022] The semiconductor light emitting device according to one aspect of the present invention may also be, [7] "In the semiconductor light emitting device described in [6] above, the resistor section includes a plurality of partial circuits connected in parallel with each other between the one end and the other end of the resistor section, each of the plurality of partial circuits includes a resistor and a third switch connected in series with each other between the one end and the other end of the resistor section, and the switching action of the plurality of switch sections is synchronized with the switching action of the third switch." According to the semiconductor light emitting device described in [7], the resistance value of the resistor section can be made variable, and the switching action of the plurality of switch sections can be synchronized with the action of changing the resistance value of the resistor section.

[0023] The semiconductor light emitting device of one aspect of the present invention may also be, [8] "In the semiconductor light emitting device described in [5] above, the common current source circuit further comprises: an operational amplifier that supplies an input voltage to one of a pair of input terminals; a transistor having a control terminal connected to the output terminal of the operational amplifier; and a resistor, one end of which is connected to the current terminal of the transistor and the other input terminal of the operational amplifier, and the other end is connected to a fourth constant potential line, and the switching action of the plurality of switch units is synchronized with the action of switching the value of the input voltage." According to the semiconductor light emitting device described in [8], the current value generated by the current source circuit changes by switching the value of the input voltage. Furthermore, by synchronizing the switching action of the plurality of switch units with the action of switching the value of the input voltage, the value of the drive current supplied to each iPM laser can be set for each iPM laser.

[0024] The semiconductor light emitting device according to one aspect of the present invention may also be, [9] "In the semiconductor light emitting device described in [5] above, the driving circuit further comprises: a serial-to-parallel converter for converting a serial signal into a parallel signal, the serial signal including digital data indicating a current indication value for the common current source circuit; and a digital-to-analog converter for converting the digital data converted into the parallel signal into an analog signal, the common current source circuit generating a current having a magnitude corresponding to the indication value based on the analog signal". According to the semiconductor light emitting device described in [9], digital data indicating an indication value of a current for the common current source circuit can be received from the outside as a serial signal, so the number of wiring can be reduced.

[0025] A semiconductor light-emitting device according to one aspect of the present invention may also be,

[10] "In the semiconductor light-emitting device described in any one of [1] to [9] above, each of the plurality of iPM lasers comprises: an active layer as a light-emitting portion; a phase modulation layer optically coupled to the active layer; a first cladding layer located on the first surface side of the active layer and the phase modulation layer; a second cladding layer located on the second surface side of the active layer and the phase modulation layer; a second electrode located on the second surface side of the second cladding layer; and a first electrode located on the first surface side of the first cladding layer, the phase modulation layer comprising: a basic layer; and a first electrode layer distributed in a two-dimensional manner on a surface perpendicular to the normal direction of the first surface. The basic layer is provided with a plurality of different refractive index regions having a refractive index different from that of the basic layer, and in a state where a virtual square grid is set on the surface, the plurality of different refractive index regions are arranged in a state where the center of gravity of each of the plurality of different refractive index regions is separated from the corresponding grid point by a predetermined distance, and the angle around each grid point in the virtual square grid, that is, the angle of the line segment connecting the center of gravity of each of the plurality of different refractive index regions and the corresponding grid point relative to the virtual square grid, is set according to the phase distribution for forming a light image, and at least two of the angles in the plurality of different refractive index regions are different from each other. According to the semiconductor light emitting device described in

[10] , an iPM laser can be appropriately realized.

[0026] A semiconductor light emitting device according to one aspect of the present invention may also be,

[11] "In the semiconductor light emitting device described in any one of [1] to [9] above, the plurality of iPM lasers comprises: an active layer as a light emitting portion; a phase modulation layer optically coupled to the active layer; a first cladding layer located on the first surface side of the active layer and the phase modulation layer; a second cladding layer located on the second surface side of the active layer and the phase modulation layer; a second electrode located on the second surface side of the second cladding layer; and a first electrode located on the first surface side of the first cladding layer, the phase modulation layer comprising: a basic layer; and a first electrode located perpendicular to the normal direction of the first surface. The semiconductor light emitting device according to

[11] is provided in the basic layer in a two-dimensional distribution manner on a straight surface, and has a plurality of different refractive index regions with a refractive index different from that of the basic layer. When an imaginary square lattice is set on the surface, the plurality of different refractive index regions are arranged in a manner that the center of gravity of each of the plurality of different refractive index regions is located on a straight line passing through a corresponding lattice point and inclined with respect to the imaginary square lattice, and the distance along the straight line between the center of gravity of each of the plurality of different refractive index regions and the corresponding lattice point is set according to a phase distribution for forming a light image, and the slope of the straight line is uniform in the plurality of different refractive index regions. According to the semiconductor light emitting device described in

[11] , an iPM laser can be appropriately realized.

[0027] A semiconductor light emitting device according to one aspect of the present invention may be,

[12] "In the semiconductor light emitting device described in any one of [1] to

[11] above, the plurality of iPM lasers are each formed as a monolithic. According to the semiconductor light emitting device described in

[12] , a plurality of iPM lasers are formed in a single element, which facilitates the assembly of the semiconductor light emitting device.

[0028] The semiconductor light emitting device according to one aspect of the present invention may also be,

[13] "In the semiconductor light emitting device described in

[12] above, the plurality of iPM lasers and the driving circuit are provided on a substrate that is common to each other." According to the semiconductor light emitting device described in

[13] , the driving circuit and the plurality of iPM lasers formed as a single chip can be integrated on a common substrate, thereby further miniaturizing the device.

[0029] The semiconductor light emitting device according to one aspect of the present invention may also be,

[14] "In the semiconductor light emitting device described in any one of [1] to

[11] above, it also has a supporting substrate, the supporting substrate includes a third surface and a fourth surface opposite to the third surface, and the plurality of iPM lasers are individually mounted on the third surface in a manner such that the second surface is opposite to the third surface." According to the semiconductor light emitting device described in

[14] , a plurality of iPM lasers can be formed separately (discretely) on the supporting substrate.

[0030] The semiconductor light emitting device according to one aspect of the present invention may also be,

[15] "In the semiconductor light emitting device described in

[14] above, the drive circuit is arranged on the third surface or the fourth surface of the support substrate." According to the semiconductor light emitting device described in

[15] , the drive circuit and a plurality of discretely formed iPM lasers can be integrated on the support substrate, thereby further miniaturizing the device.

[0031] The semiconductor light emitting device of one aspect of the present invention may also be

[16] "In the semiconductor light emitting device described in any one of [1] to

[12] above, the drive circuit is connected to the multiple iPM lasers by bump bonding." According to the semiconductor light emitting device described in

[16] , the drive circuit is connected to the multiple iPM lasers by bump bonding, thereby integrating the drive circuit and the multiple iPM lasers, and further miniaturizing the device.

[0032] Effects of the Invention

[0033] According to one aspect of the present invention, it is possible to provide a semiconductor light emitting device capable of reducing heat generation and achieving miniaturization of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The diagram is a structural diagram of a semiconductor light emitting device according to one embodiment.

[0035] Figure 2 yes Figure 1 A top view of the semiconductor light emitting device shown.

[0036] Figure 3 It is along Figure 2 The III-III line shown is a schematic diagram of the cross section of each iPM laser.

[0037] Figure 4 yes Figure 3 A top view of the phase modulation layer is shown.

[0038] Figure 5 It is a magnified representation Figure 4 A diagram of a portion (unit constituent area) of a phase modulation layer is shown.

[0039] Figure 6 It is a diagram for explaining the coordinate transformation from spherical coordinates to coordinates in the XYZ orthogonal coordinate system.

[0040] Figure 7 FIG. 1 is a top view showing a reciprocal lattice space associated with the phase modulation layer of each iPM laser oscillating at the M point.

[0041] Figure 8 This is a conceptual diagram for explaining a state in which a diffraction vector is applied to a wave number vector within a plane.

[0042] Fig. 9 This is a diagram for schematically explaining the peripheral structure of a light line.

[0043] Fig.10 This is a diagram conceptually showing an example of rotation angle distribution.

[0044] Fig.11 This is a conceptual diagram for explaining a state in which a diffraction vector is added to a vector obtained by removing the wave number spread from the in-plane wave number vector of a direction.

[0045] Fig.12 It is a top view of the phase modulation layer of the first modification example.

[0046] Fig.13 It is a magnified representation Fig.12 A diagram of a portion (unit constituent area) of a phase modulation layer is shown.

[0047] Fig.14 yes Figure 1 The overall block diagram of the driving circuit is shown.

[0048] Fig.15 yes Figure 1The circuit diagram of the driving circuit is shown.

[0049] Fig.16 yes Fig.15 Detailed circuit diagram of the current source circuit shown.

[0050] Fig.17 Yes means Fig.14 The diagram shows the structure of the switch action unit.

[0051] Fig.18 This is a schematic diagram showing the structure of a three-dimensional measuring device.

[0052] Fig.19 It means by Fig.18 A diagram of a sinusoidal fringe pattern formed by the three-dimensional measurement device shown.

[0053] Fig. 20 (a) and (b) are diagrams showing the first stripe element and the second stripe element.

[0054] Fig.21 (a) and (b) are diagrams showing the third stripe element and the fourth stripe element.

[0055] Fig. 22 This is a diagram showing a stripe pattern generated by synthesizing the first to fourth stripe elements.

[0056] Fig.23 (a) and (b) are diagrams showing the first stripe pattern and the second stripe pattern.

[0057] Fig.24 (a) and (b) are diagrams showing the third and fourth stripe patterns.

[0058] Fig.25 (a) and (b) are diagrams showing current source circuits of the first and second variants.

[0059] Fig.26 It is a side view of the semiconductor light emitting device of the third variant.

[0060] Fig. 27 It is a side view of the semiconductor light emitting device of the fourth variant.

[0061] Fig.28 It is a part of the cross-sectional view of the semiconductor light emitting device of the fifth variant.

[0062] Fig.29 It is a part of the cross-sectional view of the semiconductor light emitting device of the 6th variant.

[0063] Fig.30 It is an exploded perspective view showing the structure of a light source device according to a second embodiment of the present invention.

[0064] Fig.31 (a) and (b) schematically show a situation where light beams each including fringe elements are projected from four iPM lasers onto a common projection area.

[0065] Fig.32 (a) and (b) schematically show a situation where light beams each including fringe elements are projected from four iPM lasers onto a common projection area.

[0066] Fig.33 (a) and (b) schematically show a situation in which light beams each including fringe elements are projected from four iPM lasers onto a common projection area in a comparative example.

[0067] Fig.34 (a) and (b) schematically show a situation in which light beams each including fringe elements are projected from four iPM lasers onto a common projection area in a comparative example.

[0068] Fig.35 This is a diagram for explaining a problem caused by positional deviation of bright lines in the above-mentioned comparative example.

[0069] Fig.36 This is a graph showing the relationship between the distance and the deviation of the center angle when the arrangement pitch is set to 0.25 mm in mathematical formula (35).

[0070] Fig.37 (a) and (b) are diagrams for explaining a modified example of the second embodiment.

[0071] Fig.38 (a) and (b) are diagrams for explaining a modified example of the second embodiment.

[0072] Fig.39 (a) and (b) are diagrams for explaining a comparative example of a modification example of the second embodiment.

[0073] Fig.40 (a) and (b) are diagrams for explaining a comparative example of a modification example of the second embodiment.

[0074] Fig.41 (a) and (b) are diagrams for explaining another modified example of the second embodiment.

[0075] Fig.42 (a) and (b) are diagrams for explaining another modified example of the second embodiment.

[0076] Fig.43This is a diagram showing conversion between binary code and Gray code, which is another method of expressing decimal numbers and binary numbers.

[0077] Fig.44 This is a diagram showing an example of a combination of stripe patterns including a Gray code.

[0078] Fig.45 It is a perspective view showing the structure of a light source device according to a third embodiment of the present invention.

[0079] Fig.46 It is a perspective view showing the structure of a light source device according to a third embodiment of the present invention.

[0080] Fig.47 It is a perspective view showing the structure of a light source device according to a modified example of the third embodiment.

[0081] Fig.48 It is a perspective view showing the structure of a light receiving and emitting module according to a fourth embodiment of the present invention.

[0082] Fig.49 It is a perspective view showing the structure of a light receiving and emitting module according to a modified example of the fourth embodiment.

[0083] Fig.50 It is a perspective view showing the structure of a light receiving and emitting module according to another modified example of the fourth embodiment. DETAILED DESCRIPTION

[0084] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each of the drawings, the same or corresponding parts are denoted by the same reference numerals, and repeated descriptions are omitted.

[0085] (First embodiment)

[0086] [Structure of semiconductor light emitting device]

[0087] Figure 1 FIG. 1 is a structural diagram of a semiconductor light emitting device 1 according to a first embodiment. Figure 1As shown, the semiconductor light emitting device 1 includes a plurality of iPM lasers 2 and a driving circuit 3. The plurality of iPM lasers 2 each have a first surface 2a and a second surface 2b on the opposite side (opposite) to the first surface 2a. The driving circuit 3 has a surface 3a opposite to the second surface 2b. The driving circuit 3 has a current source circuit 31, a plurality of current mirror circuits 32, and a switch action unit 34. The plurality of current mirror circuits 32 are electrically connected to the plurality of iPM lasers 2, respectively. The switch action unit 34 is electrically connected to the plurality of iPM lasers 2. For example, electrical contacts corresponding to the plurality of current mirror circuits 32 and the switch action unit 34 are formed on the surface 3a, and the plurality of current mirror circuits 32 and the switch action unit 34 are connected to the plurality of iPM lasers 2 through bump bonding via the electrical contacts. The semiconductor light emitting device 1 also includes a semiconductor region 2d and a semiconductor substrate 20. The semiconductor region 2d surrounds the plurality of iPM lasers 2 in a ring shape. A plurality of iPM lasers 2 are formed on a semiconductor substrate 20, and the semiconductor substrate 20 is composed of a semiconductor such as GaAs. The planar shape of the semiconductor substrate 20 is a square or a rectangle, and a first electrode 27 is formed at each of the four corners of the back side of the semiconductor substrate 20, which forms an ohmic contact with the back side of the semiconductor substrate 20 and defines a reference potential. In this way, a plurality of iPM lasers 2 are formed on a common semiconductor substrate 20. In other words, a plurality of iPM lasers 2 are formed as a single chip. Adjacent iPM lasers 2 are formed at a certain interval. The plurality of iPM lasers 2 output lasers containing desired light images from the first surface 2a, respectively. The drive circuit 3 supplies a drive current for causing each of the plurality of iPM lasers 2 to emit light. The semiconductor region 2d disperses the load applied to each iPM laser 2 when the iPM laser 2 is mounted on the drive circuit 3, thereby improving flatness. In the following description, a direction perpendicular to the first surface 2a is referred to as a Z-axis direction, a direction parallel to the first surface 2a is referred to as an X-axis direction, and a direction perpendicular to both the Z-axis direction and the X-axis direction is referred to as a Y-axis direction.

[0088] Figure 2 yes Figure 1 The top view of the semiconductor light emitting device 1 is shown. Figure 2 The semiconductor region 2d is omitted in the figure. The multiple iPM lasers 2 are arranged in a matrix in two dimensions, with the X-axis direction and the Y-axis direction as the row direction and the column direction, respectively. In the present embodiment, there are four iPM lasers 2 in the X-axis direction (row direction) and four iPM lasers 2 in the Y-axis direction (column direction), a total of sixteen iPM lasers 2.

[0089] [Structure of iPM laser]

[0090] Figure 3 It is along Figure 2The III-III line shown is a schematic diagram of a cross section of each iPM laser 2. Each iPM laser 2 forms a standing wave in a plane direction parallel to an imaginary plane formed by the X-axis direction and the Y-axis direction, and outputs a plane wave after phase control in the Z-axis direction. As described later, light forming a two-dimensional optical image of an arbitrary shape is output along the normal direction (i.e., Z-axis direction) of the main surface 20a of the semiconductor substrate 20, the oblique direction intersecting the normal direction, or both the normal direction and the oblique direction.

[0091] Each iPM laser 2 includes: an active layer 22 as a light emitting portion provided on a semiconductor substrate 20; a phase modulation layer 25A optically coupled to the active layer 22; a first cladding layer 21 located on the first surface 2a side relative to the active layer 22 and the phase modulation layer 25A; a second cladding layer 23 located on the second surface 2b side relative to the active layer 22 and the phase modulation layer 25A; and a contact layer 24 provided on the second cladding layer 23. These semiconductor substrate 20, first cladding layer 21, active layer 22, second cladding layer 23, and contact layer 24 are composed of, for example, compound semiconductors such as GaAs-based semiconductors, InP-based semiconductors, and nitride-based semiconductors. Each energy band gap of the first cladding layer 21 and the second cladding layer 23 is larger than the energy band gap of the active layer 22. The thickness direction of the semiconductor substrate 20, the first cladding layer 21, the active layer 22, the second cladding layer 23, and the contact layer 24 coincides with the Z-axis direction.

[0092] In this embodiment, the phase modulation layer 25A is provided between the active layer 22 and the second cladding layer 23. The phase modulation layer 25A may also be provided between the first cladding layer 21 and the active layer 22. As required, a photoconductive layer may be provided between at least one of the active layer 22 and the second cladding layer 23 and between the active layer 22 and the first cladding layer 21. The thickness direction of the phase modulation layer 25A coincides with the Z-axis direction. The photoconductive layer may include a carrier blocking layer for effectively confining carriers in the active layer 22.

[0093] A separation region 2g is formed between adjacent iPM lasers 2. The separation region 2g is a slit (gap) formed by dry etching or wet etching. The separation region 2g is insulated by forming an insulating film 28 such as SiN on the sidewall of the slit, thereby suppressing current leakage caused by solder during assembly. The separation region 2g can also be formed by insulating a semiconductor layer modified by high-intensity light (electric field), impurity diffusion, and ion implantation.

[0094] The phase modulation layer 25A includes a basic layer 25a and a plurality of different refractive index regions 25b. The basic layer 25a is composed of a first refractive index medium. Each of the different refractive index regions 25b is composed of a second refractive index medium having a refractive index different from that of the first refractive index medium, and exists in the basic layer 25a. The two-dimensional configuration of the plurality of different refractive index regions 25b includes a substantially periodic structure. When the equivalent refractive index of the mode is set to n, the wavelength λ0 (=(√2)×a×n, a is the lattice spacing) selected by the phase modulation layer 25A is included in the emission wavelength range of the active layer 22. The phase modulation layer 25A is capable of selectively outputting light of a band end wavelength near the wavelength λ0 of the emission wavelength of the active layer 22 to the outside. The laser light incident into the phase modulation layer 25A forms a prescribed mode corresponding to the configuration of the different refractive index regions 25b in the phase modulation layer 25A, and is emitted from the first surface 2a to the outside as a laser beam having a desired pattern.

[0095] Each iPM laser 2 further includes a second electrode 26 provided on the contact layer 24 and a first electrode 27 provided on the back surface 20b of the semiconductor substrate 20 (see Figure 1 ). The second electrode 26 is located on the second surface 2b side relative to the second cladding layer 23, and forms an ohmic contact with the contact layer 24. The first electrode 27 is located on the first surface 2a side of the first cladding layer 21, and forms an ohmic contact with the semiconductor substrate 20. The second electrode 26 is provided in the central area of ​​the contact layer 24. The portion other than the second electrode 26 on the contact layer 24 is covered by the insulating film 28. The contact layer 24 that is not in contact with the second electrode 26 may also be removed. The portion other than the first electrode 27 on the back side 20b of the semiconductor substrate 20 is covered by the anti-reflection film 29.

[0096] When a driving current is supplied between the second electrode 26 and the first electrode 27, recombination of electrons and holes occurs in the active layer 22, and light is emitted into the active layer 22. The electrons and holes contributing to the light emission in the active layer 22 and the generated light are effectively confined between the first cladding layer 21 and the second cladding layer 23.

[0097] The light output from the active layer 22 enters the interior of the phase modulation layer 25A, and forms a predetermined pattern corresponding to the lattice structure inside the phase modulation layer 25A. The laser light output from the phase modulation layer 25A is directly output from the back surface 20b to the outside of each iPM laser 2, or is output from the back surface 20b to the outside of each iPM laser 2 after being reflected by the second electrode 26. At this time, the signal light included in the laser light is output along the normal direction of the main surface 20a, or along the oblique direction intersecting the normal direction, or both. The signal light forms the desired optical image in the output light. The signal light is mainly 1st order light and -1st order light.

[0098] Figure 4 yes Figure 3 The phase modulation layer 25A shown in FIG. 2 is a top view of the phase modulation layer 25A. The phase modulation layer 25A includes a basic layer 25a and a plurality of different refractive index regions 25b. The basic layer 25a is composed of a first refractive index medium. The plurality of different refractive index regions 25b are composed of a second refractive index medium having a refractive index different from that of the first refractive index medium. Here, a virtual square lattice is set on one surface of the phase modulation layer 25A that coincides with a surface parallel to a surface formed by the X-axis direction and the Y-axis direction. One side of the square lattice is parallel to the X-axis, and the other side is parallel to the Y-axis. At this time, a square unit constituent area R (x, y) centered at a lattice point O of the square lattice can be set in a two-dimensional state over multiple columns (x=0, 1, 2, 3, ···) along the X-axis and multiple rows (y=0, 1, 2, ···) along the Y-axis. If the XY coordinates of each unit constituent area R are given at the centroid position of each unit constituent area R, the centroid position coincides with the lattice point O of the virtual square lattice. For example, one different refractive index region 25b is provided in each unit constituent region R. The planar shape of the different refractive index region 25b is, for example, circular. The lattice point O may be located outside the different refractive index region 25b or may be included inside the different refractive index region 25b.

[0099] The ratio of the area S of the different refractive index region 25b to one unit structural region R is called the filling factor (FF). If the grid spacing of the square grid is a, the filling factor FF of the different refractive index region 25b is given by S / a. 2 S is the area of ​​the different refractive index region 25b in the XY plane. For example, when the shape of the different refractive index region 25b is a perfect circle, the diameter d of the perfect circle is used as S=π(d / 2) 2 When the shape of the different refractive index region 25b is a square, the length LA of one side of the square is used as S=LA 2 And given.

[0100] Figure 5 It is a magnified representation Figure 4 FIG. 2 is a diagram of a portion (unit constituent region R) of the phase modulation layer 25A shown in FIG. Figure 5As shown, the different refractive index regions 25b each have a center of gravity G, and the position of the center of gravity G in the unit constituent region R is given by the s-axis and the t-axis that are orthogonal to the lattice point O. Here, in the unit constituent region R(x,y) defined by the s-axis and the t-axis that are orthogonal to each other, the angle between the vector from the lattice point O(x,y) toward the center of gravity G and the s-axis is set to φ(x,y). x represents the position of the xth lattice point along the X-axis, and y represents the position of the yth lattice point along the Y-axis. When the angle φ is 0°, the direction of the vector connecting the lattice point O(x,y) and the center of gravity G coincides with the positive direction of the X-axis. The length of the vector connecting the lattice point O(x,y) and the center of gravity G is set to r(x,y). In one example, r(x,y) is constant regardless of x and y (over the entire phase modulation layer 25A).

[0101] like Figure 4 As shown, the direction of the vector connecting the lattice point O(x, y) and the center of gravity G (the center of gravity of the corresponding different refractive index region 25b), that is, the angle φ around the lattice point of the center of gravity G of the different refractive index region 25b corresponds to the desired light image, and is set individually for each lattice point O(x, y) according to the phase pattern. The phase pattern, that is, the angle φ(x, y), has a specific value at each position determined by the values ​​of x and y, but is not necessarily represented by a specific function. That is, the angle φ(x, y) is determined based on the phase distribution extracted from the complex amplitude distribution obtained by inverse Fourier transforming the desired light image. At least two of the angles of the multiple different refractive index regions 25b are different from each other. When obtaining the complex amplitude distribution based on the desired light image, the reproducibility of the light beam pattern is improved by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method generally used in the calculation of hologram generation.

[0102] The beam pattern output from the phase modulation layer 25A includes, for example, a stripe pattern. In order to obtain a desired beam pattern, the distribution of the angle φ(x, y) of the different refractive index regions 25 b in the phase modulation layer 25A is determined by the following procedure.

[0103] As the first prerequisite, in an XYZ orthogonal coordinate system defined by a Z axis consistent with the normal direction and an XY plane consistent with a surface of a phase modulation layer 25A including a plurality of different refractive index regions 25b, an imaginary square lattice consisting of M1 (an integer greater than 1) × N1 (an integer greater than 1) unit regions R having a square shape is set on the XY plane.

[0104] As the second prerequisite, the coordinates (ξ,η,ζ) in the XYZ orthogonal coordinate system are as follows Figure 6 As shown, relative to the length r of the radius vector and the inclination angle θ from the Z axis tilt , the rotation angle θ from the X axis determined on the XY planerot The specified spherical coordinates (r,θ rot ,θ tilt ), satisfying the relationship shown in the following mathematical formulas (1) to (3). Figure 6 It is used to illustrate the conversion from spherical coordinates (r,θ rot ,θ tilt ) to the coordinates (ξ,η,ζ) in the XYZ orthogonal coordinate system. The designed optical image on a predetermined plane set in the XYZ orthogonal coordinate system which is the actual space is expressed by the coordinates (ξ,η,ζ).

[0105] When a beam pattern corresponding to the light image output from each iPM laser 2 is directed toward an angle θ tilt and θ rot When the bright spots are gathered in a specified direction, the angle θ tilt and θ rot The normalized wave number K corresponding to the X-axis is converted to K as given by the following mathematical formula (4): x The coordinate value k on the axis x The normalized wave number defined by the following mathematical formula (5) corresponds to the Y axis and is K x Axis orthogonal k y The coordinate value k on the axis y The normalized wave number is the wave number normalized by setting the wave number 2π / a corresponding to the grid spacing of the imaginary square grid to 1.0. x Axis and K y In the wave number space specified by the axis, a specific wave number range containing a beam pattern corresponding to the light image is composed of square M2 (an integer greater than 1) × N2 (an integer greater than 1) image regions FR. The integer M2 does not need to be consistent with the integer M1. Similarly, the integer N2 does not need to be consistent with the integer N1. Mathematical formula (4) and mathematical formula (5) are disclosed in, for example, non-patent document 2.

[0106] [Mathematical formula 1]

[0107] ξ=rsinθ tilt cosθ rot …(1)

[0108] [Mathematical formula 2]

[0109] η=rsinθ tilt sinθ rot …(2)

[0110] [Mathematical formula 3]

[0111] ζ=rcosθ tilt …(3)

[0112] [Formula 4]

[0113]

[0114] [Mathematical formula 5]

[0115]

[0116] In equations (4) and (5), a represents a lattice constant of a virtual square lattice, and λ represents an oscillation wavelength of each iPM laser 2 .

[0117] As the third premise, in wave number space, by x The coordinate component k in the axis direction x (an integer greater than or equal to M2-1 and less than or equal to M2-1) and K y The coordinate component k in the axis direction y (an integer greater than or equal to N2-1 and less than or equal to N2-1) determines the image region FR (k x , k y ) is respectively transformed by two-dimensional discrete Fourier inverse transform into a unit constituent area R(x,y) on the XY plane determined by the coordinate component x (an integer greater than 0 and less than M1-1) in the X-axis direction and the coordinate component y (an integer greater than 0 and less than N1-1) in the Y-axis direction, and the complex amplitude F(x,y) is given by the following mathematical formula (6) with j as the imaginary unit. When the amplitude term is set to A(x,y) and the phase term is set to P(x,y), the complex amplitude F(x,y) is defined by the following mathematical formula (7). As a fourth prerequisite, the unit constituent area R(x,y) is defined by the s-axis and t-axis which are parallel to the X-axis and the Y-axis respectively and are orthogonal to the lattice point O(x,y) which is the center of the unit constituent area R(x,y).

[0118] [Mathematical formula 6]

[0119]

[0120] [Mathematical formula 7]

[0121] F(x,y)=A(x,y)×exp[jP(x,y)]…(7)

[0122] Under the above-mentioned first to fourth prerequisites, the phase modulation layer 25A is configured to satisfy the following fifth and sixth conditions. That is, the fifth condition is satisfied by configuring the unit configuration area R (x, y) in a state where the center of gravity G is away from the grid point O (x, y). The sixth condition is that, in a state where the line segment length r (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 M1 × N1 unit configuration areas R, 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 satisfies

[0123] φ(x,y)=C×P(x,y)+B

[0124] C: proportional constant, such as 180° / π

[0125] B: Any constant, such as 0

[0126] In a manner related to each other, the corresponding different refractive index regions 25b are configured in the unit constituent region R(x, y).

[0127] Each iPM laser 2 can oscillate at the Γ point or at the M point. Next, the M point oscillation of each iPM laser 2 is described. In order for each iPM laser 2 to oscillate at the M point, the lattice spacing a of the imaginary square lattice, the emission wavelength λ of the active layer 22, and the equivalent refractive index n of the mode can satisfy the conditions such as λ=(√2)n×a. Figure 7 : is a top view showing the reciprocal lattice space of the phase modulation layer of each iPM laser 2 oscillating about the M point. The point P in the figure represents the reciprocal lattice point. The arrow B1 in the figure represents the basic reciprocal lattice vector, and the arrows K1, K2, K3 and K4 represent four in-plane wave number vectors. The in-plane wave number vectors K1 to K4 each have a wave number spread SP based on the rotation angle distribution φ(x, y).

[0128] The shape and size of the wave number spread SP are the same as those in the case of the Γ point oscillation described above. In each iPM laser 2 oscillating at the M point, the size of the in-plane wave number vectors K1 to K4 (i.e., the size of the standing wave in the in-plane direction) is smaller than the size of the basic reciprocal lattice vector B1. Therefore, the vector sum of the in-plane wave number vectors K1 to K4 and the basic reciprocal lattice vector B1 will not become 0, and the wave number in the in-plane direction will not become 0 due to diffraction, so no diffraction will occur in the direction perpendicular to the surface (Z-axis direction). In this state, in each iPM laser 2 oscillating at the M point, the 0th order light in the direction perpendicular to the surface (Z-axis direction), the 1st order light in the direction inclined relative to the Z-axis direction, and the -1st order light are not output.

[0129] In this embodiment, by taking the following steps on the phase modulation layer 25A in each iPM laser 2 oscillating at the M point, it is possible to output a part of the 1st order light and the -1st order light instead of the 0th order light. Specifically, Figure 8 As shown, by adding a diffraction vector V having a certain size and direction to the in-plane wave number vectors K1 to K4, the size of at least one of the in-plane wave number vectors K1 to K4 (in the figure, the in-plane wave number vector K3) is made smaller than 2π / λ. In other words, at least one of the in-plane wave number vectors K1 to K4 (in-plane wave number vector K3) after the diffraction vector V is applied is converged within a circular region (light ray) LL of a radius of 2π / λ.

[0130] exist Figure 8The in-plane wave number vectors K1 to K4 shown by the dotted lines represent the wave number vectors K1 to K4 before the addition of the diffraction vector V, and the in-plane wave number vectors K1 to K4 shown by the solid lines represent the wave number vectors K1 to K4 after the addition of the diffraction vector V. The light ray LL corresponds to the total reflection condition, and the wave number vector of the size converged within the light ray LL has a component in the plane perpendicular 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 size of the diffraction vector V is in the range of 2π / (√2)a-2π / λ to 2π / (√2)a+2π / λ, and as an example, it is 2π / (√2)a.

[0131] Next, the magnitude and direction of the diffraction vector V for converging at least one of the in-plane wave number vectors K1 to K4 within the light ray LL are examined. The following mathematical expressions (8) to (11) represent the in-plane wave number vectors K1 to K4 before the diffraction vector V is applied.

[0132] [Mathematical formula 8]

[0133]

[0134] [Mathematical formula 9]

[0135]

[0136] [Formula 10]

[0137]

[0138] [Mathematical formula 11]

[0139]

[0140] Extension of the wave number vector Δk x and Δk y The following mathematical expressions (12) and (13) are satisfied respectively. The maximum value Δk of the expansion of the in-plane wave number vector in the x-axis direction is xmax and the maximum value of the expansion in the y-axis direction Δk ymax Determined by the angular spread of the designed light image.

[0141] [Mathematical formula 12]

[0142] -Δkx max ≤Δkx≤Δkx max …(12)

[0143] [Mathematical formula 13]

[0144] -Δky max ≤Δky≤Δky max …(13)

[0145] When the diffraction vector V is expressed as in the following mathematical formula (14), the in-plane wave number vectors K1 to K4 to which the diffraction vector V is applied are expressed as in the following mathematical formulas (15) to (18).

[0146] [Mathematical formula 14]

[0147] V=(Vx,Vy)…(14)

[0148] [Mathematical formula 15]

[0149]

[0150] [Formula 16]

[0151]

[0152] [Mathematical formula 17]

[0153]

[0154] [Mathematical formula 18]

[0155]

[0156] If it is considered that any of the wave number vectors K1 to K4 in equations (15) to (18) converges within the light ray LL, the relationship of the following equation (19) holds.

[0157] [Mathematical formula 19]

[0158]

[0159] That is, by adding the diffraction vector V that satisfies the mathematical formula (19), any of the wave number vectors K1 to K4 converges within the light beam LL, and a part of the 1st order light and the -1st order light is output.

[0160] The reason why the size (radius) of the light ray LL is set to 2π / λ is as follows. Fig. 9 This is a diagram for schematically illustrating the structure of the periphery of the light LL. In this figure, the boundary between the device and the air is shown when viewed from a direction perpendicular to the Z-axis direction. The magnitude of the wave number vector of light in a vacuum is 2π / λ, but Fig. 9 As shown in Figure 1, when light propagates in a device medium, the magnitude of the wave number vector Ka in a medium with a refractive index of n is 2πn / λ. At this time, in order for light to propagate at the boundary between the device and air, the wave number component parallel to the boundary needs to be continuous (wave number conservation law).

[0161] exist Fig. 9In the case where the wave number vector Ka forms an angle θ with the Z axis, the length of the wave number vector Kb projected into the plane (i.e., the in-plane wave number vector) is (2πn / λ)sinθ. On the other hand, generally, according to the relationship that the refractive index of the medium n>1, when the in-plane wave number vector Kb in the medium is greater than the angle of 2π / λ, the law of conservation of wave number does not hold. At this time, the light is totally reflected and cannot be taken out to the air side. The size of the wave number vector corresponding to this total reflection condition becomes the size of the light LL, i.e., 2π / λ.

[0162] As an example of a specific method of adding the diffraction vector V to the wave number vectors K1 to K4 in the plane, consider a method of superimposing a rotation angle distribution (second phase distribution) that is unrelated to the light image on the phase distribution corresponding to the light image, that is, the rotation angle distribution φ1(x, y) (first phase distribution). In this case, the rotation angle distribution φ(x, y) of the phase modulation layer 25A is expressed as φ(x, y) = φ1(x, y) + φ2(x, y). φ1(x, y) is equivalent to the phase of the complex amplitude when the light image is Fourier transformed as described above. φ2(x, y) is a rotation angle distribution for adding the diffraction vector V that satisfies the above mathematical formula (19).

[0163] Fig.10 This is a diagram conceptually showing an example of the rotation angle distribution φ2(x, y). In the example of this 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 each time. By arranging the phase values ​​in this way, the diffraction vector V along the Γ-M1 axis or the Γ-M2 axis can be appropriately realized. In the case of the checkered pattern arrangement, V = (±π / a, ±π / a), and the diffraction vector V and Figure 7 The wave number vectors K1 to K4 cancel each other out. The angular distribution φ2(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 φ2(x, y) of the diffraction vector V is represented by φ2(x, y) = V·r = Vxx + Vyy.

[0164] In the above-mentioned embodiment, when the wave number expansion based on the angular expansion of the light image is contained in a circle of radius Δk centered at a certain point in the wave number space, it can also be briefly considered as follows. By adding the diffraction vector V to the in-plane wave number vectors K1 to K4 in the four directions, the size of at least one of the in-plane wave number vectors K1 to K4 in the four directions is made smaller than 2π / λ (light LL). This can be considered as adding the diffraction vector V to the vector obtained by removing the wave number expansion Δk from the in-plane wave number vectors K1 to K4 in the four directions, so that the size of at least one of the in-plane wave number vectors K1 to K4 in the four directions is smaller than the value {(2π / λ)-Δk} obtained by subtracting the wave number expansion Δk from 2π / λ.

[0165] Fig.11 This is a diagram conceptually showing the above state. As shown in the figure, if the diffraction vector V is added to the in-plane wave number vectors K1 to K4 after removing the wave number spread Δk, the size of at least one of the in-plane wave number vectors K1 to K4 is smaller than {(2π / λ)-Δk}. Fig.11 In the example, region LL2 is a circular region with a radius of {(2π / λ)-Δk}. Fig.11 In the figure, the dotted lines represent the in-plane wave number vectors K1 to K4 before the addition of the diffraction vector V, and the solid lines represent the in-plane wave number vectors K1 to K4 after the addition of the diffraction vector V. Region LL2 corresponds to the total reflection condition taking into account the wave number spread Δk, and the wave number vectors of the size converging within region LL2 also propagate in the plane perpendicular direction (Z-axis direction).

[0166] In this embodiment, the size and direction of the diffraction vector V for converging at least one of the in-plane wave number vectors K1 to K4 within the region LL2 are described. The following mathematical expressions (20) to (23) represent the in-plane wave number vectors K1 to K4 before the diffraction vector V is applied.

[0167] [Mathematical formula 20]

[0168]

[0169] [Mathematical formula 21]

[0170]

[0171] [Mathematical formula 22]

[0172]

[0173] [Mathematical formula 23]

[0174]

[0175] Here, when the diffraction vector V is expressed as in the aforementioned mathematical formula (14), the in-plane wave number vectors K1 to K4 after adding the diffraction vector V become the following mathematical formulas (24) to (27).

[0176] [Mathematical formula 24]

[0177]

[0178] [Mathematical formula 25]

[0179]

[0180] [Mathematical formula 26]

[0181]

[0182] [Mathematical formula 27]

[0183]

[0184] In equations (24) to (27), if it is considered that any one of the in-plane wave number vectors K1 to K4 converges within region LL2, the relationship of the following equation (28) holds. That is, by adding the diffraction vector V that satisfies equation (28), any one of the in-plane wave number vectors K1 to K4 that eliminates the wave number spread Δk converges within region LL2. Even in such a case, it is possible to output a part of the 1st order light and the -1st order light without outputting the 0th order light.

[0185] [Mathematical formula 28]

[0186]

[0187] Fig.12 It is a top view of a phase modulation layer 25B according to a modification. Fig.13 25A may be replaced by a phase modulation layer 25B. Fig.12 and Fig.13 As shown, the center of gravity G of each different refractive index region 25b of the phase modulation layer 25B of the modified example is arranged on a straight line D. The straight line D is a straight line that passes through the lattice point O corresponding to each unit constituent region R and is inclined relative to each side of the square lattice. That is, the straight line D is a straight line inclined relative to both the X-axis and the Y-axis. The inclination angle of the straight line D relative to one side (X-axis) of the square lattice is θ.

[0188] The tilt angle θ is constant in the phase modulation layer 25B. The tilt angle θ satisfies 0°<θ<90°, and in one example, θ=45°. Alternatively, the tilt 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 of the coordinate plane defined by the X-axis and the Y-axis to the third quadrant. The tilt angle θ satisfies 90°<θ<180°, and in one example, θ=135°. Alternatively, the tilt 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 of the coordinate plane defined by the X-axis and the Y-axis to the fourth quadrant. In this way, the tilt angle θ becomes an angle other than 0°, 90°, 180°, and 270°.

[0189] Here, the distance between the lattice point O and the center of gravity G is set to r(x,y). x is the position of the xth lattice point on the X-axis, and y is the position of the yth lattice point on the Y-axis. When the distance r(x,y) is a positive value, the center of gravity G is located in the 1st quadrant (or the 2nd quadrant). When the distance r(x,y) is a negative value, the center of gravity G is located in the 3rd quadrant (or the 4th quadrant). When the distance r(x,y) is 0, the lattice point O and the center of gravity G are consistent with each other. The inclination angle is preferably 45°, 135°, 225°, and 275°. At these inclination angles, only two of the four wave number vectors (for example, the in-plane wave number vectors (±π / a, ±π / a)) that form the standing wave of point M are phase modulated, and the other two are not phase modulated, so a stable standing wave can be formed.

[0190] The distance r(x, y) between the centroid G of each different refractive index region and the grid point O corresponding to each unit constituent region R is set individually for each different refractive index region 15b according to the phase pattern corresponding to the desired optical image. The phase pattern, i.e., the distribution of the distance r(x, y), has a specific value at each position determined by the values ​​of x and y, but is not necessarily represented by a specific function. The distribution of the distance r(x, y) is determined by extracting the phase distribution from the complex amplitude distribution obtained by inverse Fourier transforming the desired optical image.

[0191] That is, Fig.13As shown, when the phase P(x,y) at a certain coordinate (x,y) is P0, the distance r(x,y) is set to 0, when the phase P(x,y) is π+P0, the distance r(x,y) is set to the maximum value R0, and when the phase P(x,y) is -π+P0, the distance r(x,y) is set to the minimum value -R0. And, for the intermediate phase P(x,y), the distance r(x,y) is taken as r(x,y) = {P(x,y)-P0}×R0 / π. The initial phase P0 can be set arbitrarily.

[0192] If the grid spacing of the imaginary square grid is set to a, the maximum value R0 of r(x, y) is, for example, within the range of the following mathematical formula (29). When obtaining the complex amplitude distribution based on the desired light image, the reproducibility of the light beam pattern can be improved by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method generally used in the calculation of hologram generation.

[0193] [Mathematical formula 29]

[0194]

[0195] In this embodiment, the desired optical image can be obtained by determining the distribution of the distance r(x, y) of the different refractive index regions 25b of the phase modulation layer 25B. Under the same first to fourth preconditions as those in the above-mentioned embodiment, the phase modulation layer 25B 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 25b satisfies

[0196] r(x,y)=C×(P(x,y)-P0)

[0197] C: proportional constant, such as R0 / π

[0198] P0: any constant, such as 0

[0199] In a manner related to each other, the corresponding different refractive index regions 25b are configured in the unit constituent region R(x, y).

[0200] That is, the distance r(x, y) is set to 0 when the phase P(x, y) of a certain coordinate (x, y) is P0, is set to a maximum value R0 when the phase P(x, y) is π+P0, and is set to a minimum value -R0 when the phase P(x, y) is -π+P0. In the case of obtaining a desired optical image, the optical image can be inversely Fourier transformed, and the distribution of the distance r(x, y) corresponding to the phase P(x, y) of its complex amplitude can be assigned to a plurality of different refractive index regions 25b. The phase P(x, y) and the distance r(x, y) can also be proportional to each other.

[0201] In this mode, similarly to the above-mentioned embodiment, the lattice spacing a of the imaginary square lattice and the emission wavelength λ of the active layer 12 satisfy the condition of the M-point oscillation. Furthermore, when the reciprocal lattice space is considered in the phase modulation layer 25B, the size of at least one of the in-plane wave number vectors in the four directions respectively including the wave number expansion caused by the distribution of the distance r(x, y) can be made smaller than 2π / λ (ray).

[0202] In this embodiment, in each iPM laser 2 oscillating at the M point, the phase modulation layer 25B is modified as follows, so that the 0th order light is not output in the light beam, but a part of the 1st order light and the -1st order light is output. Specifically, Figure 8 As shown, by adding a diffraction vector V having a certain size and direction to the in-plane wave number vectors K1 to K4, the size of at least one of the in-plane wave number vectors K1 to K4 is made smaller than 2π / λ. That is, at least one of the in-plane wave number vectors K1 to K4 after the diffraction vector V is applied is made to converge within a circular area (light ray) LL of a radius of 2π / λ. By adding a diffraction vector V that satisfies the above-mentioned mathematical formula (19), any one of the in-plane wave number vectors K1 to K4 converges within the light ray LL, and a part of the 1st light and -1st light is output.

[0203] Or, if Fig.11 As shown, by adding the diffraction vector V to the value obtained by removing the wave number expansion Δk from the in-plane wave number vectors K1 to K4 in the four directions (i.e., the in-plane wave number vectors in the four directions in the square lattice PCSEL oscillating at the M point), the size of at least one of the in-plane wave number vectors K1 to K4 in the four directions can be made smaller than the value obtained by subtracting the wave number expansion Δk from 2π / λ {(2π / λ)-Δk}. That is, by adding the diffraction vector V satisfying the above-mentioned mathematical formula (28), any one of the in-plane wave number vectors K1 to K4 converges within the region LL2, and a part of the 1st light and -1st light is output.

[0204] As an example of a specific method of adding the diffraction vector V to the wave number vectors K1 to K4 within the plane, consider a method of overlapping the distance distribution r2(x,y) (second phase distribution) that is unrelated to the light image with the phase distribution corresponding to the light image, that is, the distance distribution r1(x,y) (first phase distribution). At this time, the distance distribution r(x,y) of the phase modulation layer 25B is expressed as r(x,y)=r1(x,y)+r2(x,y). As described above, r1(x,y) is equivalent to the phase of the complex amplitude when the light image is Fourier transformed. r2(x,y) is a distance distribution for adding the diffraction vector V that satisfies the above-mentioned mathematical formula (19) or mathematical formula (28). The specific example of the distance distribution r2(x,y) is the same as Fig.10 same.

[0205] [Structure of drive circuit]

[0206] Fig.14 yes Figure 1 The overall block diagram of the driving circuit 3 is shown in FIG. Fig.14 As shown in FIG. 1 , the drive circuit 3 includes a current source circuit 31, a plurality of current mirror circuits 32, a plurality of oscillation prevention circuits 33, and a switch operation unit 34. The drive circuit 3 is electrically connected to an external control circuit 4 provided outside the semiconductor light emitting device 1, and is driven according to instruction signals S1 to S3 from the external control circuit 4. The current source circuit 31 generates a drive current I for causing each iPM laser 2 to emit light. out The current source circuit 31 receives the instruction signal S1 from the external control circuit 4 and generates the operating current Iop based on the current value of the instruction signal S1. The current source circuit 31 is common to multiple iPM lasers 2. The wiring extending from the output terminal of the current source circuit 31 is branched into multiple branches, and the multiple branched wirings are respectively connected to the input terminals of multiple current mirror circuits 32. The multiple current mirror circuits 32 respectively amplify the operating current Iop generated by the current source circuit 31 as the driving current I out After that, it is supplied to each iPM laser 2. The output terminals of the multiple current mirror circuits 32 are connected to each iPM laser 2. The number of the multiple current mirror circuits 32 is the same as the number of the multiple iPM lasers 2. The output terminals of the multiple current mirror circuits 32 are also connected to the multiple oscillation prevention circuits 33, respectively.

[0207] The plurality of oscillation prevention circuits 33 suppress ringing caused by parasitic components (inductance components) of wiring between each current mirror circuit 32 and each iPM laser 2. The number of the plurality of oscillation prevention circuits 33 is the same as the number of the plurality of iPM lasers 2 and the number of the plurality of current mirror circuits 32. The switch operation unit 34 includes a first shift register 34a and a second shift register 34b. The first shift register 34a receives an instruction signal S2 from the external control circuit 4. Moreover, the first shift register 34a switches the drive current I for each column of the plurality of iPM lasers 2 based on the instruction signal S2. out The second shift register 34b receives the instruction signal S3 from the external control circuit 4. Then, based on the instruction signal S3, the second shift register 34b switches the drive current I for each row of the plurality of iPM lasers 2. out The driving current I is switched for each iPM laser 2 by both the first shift register 34a and the second shift register 34b. out By making the drive current I out is turned on, supplying a driving current I to each iPM laser 2 out .

[0208] Fig.15 yes Figure 1 The circuit diagram of the driving circuit 3 is shown in FIG. Fig.15 As shown, the current source circuit 31 includes an operational amplifier 311, an NMOS-FET (transistor) 312, a voltage source 313 and a resistor Rop. The current source circuit 31 in this embodiment uses an NMOS-FET 312, so it becomes a constant current circuit of a suction type. The drain terminal of the NMOS-FET 312 is connected to the input terminal of the current mirror circuit 32. The gate terminal (control terminal) of the NMOS-FET 312 is connected to the output terminal of the operational amplifier 311. The operational amplifier 311 has an inverting input terminal and a non-inverting input terminal as a pair of input terminals. The voltage source 313 is connected to the non-inverting input terminal (one of the pair of input terminals) of the operational amplifier 311, and is supplied with an input voltage Vop. The source terminal (current terminal) of the NMOS-FET 312 is connected to the inverting input terminal (the other of the pair of input terminals) of the operational amplifier 311, and is connected to the reference potential line GND (the fourth constant potential line) via the resistor Rop. Through the imaginary short circuit of the operational amplifier 311, a voltage equal to the input voltage Vop is applied to the node N between the source terminal of the NMOS-FET312 and the resistor Rop (for convenience, shown as Vop). Therefore, the operating current Iop has a current value obtained by dividing the voltage value of the input voltage Vop by the resistance value of the resistor Rop. One or both of the resistance value of the resistor Rop and the voltage value of the input voltage Vop output from the voltage source 313 are variable. The current value of the operating current Iop changes with the change of the voltage value of the input voltage Vop or the resistance value of the resistor Rop. Therefore, the operating current Iop is variable. By setting a PMOS-FET instead of the NMOS-FET312, the current source circuit 31 can also function as a sweep-type constant current circuit. In this case, the resistor Rop is connected between the source terminal of the PMOS-FET and the input terminal of each current mirror circuit 32. A bipolar transistor can also be set to replace the NMOS-FET or the PMOS-FET.

[0209] Each current mirror circuit 32 includes a transistor circuit 321 and a switch unit 322. Fig.15In the example, the transistor circuit 321 includes a PMOS-FET 321a and a PMOS-FET 321b. The gate terminal of the PMOS-FET 321a and the gate terminal of the PMOS-FET 321b are shared. The source terminal of the PMOS-FET 321a and the source terminal of the PMOS-FET 321b are shared. A voltage source 325 is connected to the shared source terminal. The switch unit 322 includes a first switch 322a and a second switch 322b. The first switch 322a and the second switch 322b are connected in series with each other. The on / off of the switch unit 322 is switched individually for each current mirror circuit 32 according to an instruction signal from the switch operation unit 34. The first switch 322a is connected to the first shift register 34a (see Fig.14 ) is electrically connected. The first switch 322a is switched on / off according to the instruction signal S2 from the first shift register 34a. The second switch 322b is connected to the second shift register 34b (refer to Fig.14 ) are electrically connected. The on / off of the second switch 322b is switched according to the instruction signal S3 from the second shift register 34b. When both the first switch 322a and the second switch 322b are turned on, the operating current Iop is supplied to each current mirror circuit 32.

[0210] Fig.16 yes Fig.15 The detailed circuit diagram of the current source circuit 31 is shown in FIG. Fig.16 As shown, the resistor section Rop includes a plurality of partial circuits 316a to 316d. One end of the resistor section Rop is connected to the source terminal of the NMOS-FET 312 and the inverting input terminal of the operational amplifier 311, and the other end of the resistor section Rop is connected to the reference potential line GND. The plurality of partial circuits 316a to 316d are connected in parallel to each other between one end and the other end of the resistor section Rop. The partial circuit 316a includes a resistor Rop1 and a third switch 314a connected in series with each other. The partial circuit 316b includes a resistor Rop2 and a third switch 314b connected in series with each other. The partial circuit 316c includes a resistor Rop3 and a third switch 314c connected in series with each other. The partial circuit 316d includes a resistor Rop4 and a third switch 314d connected in series with each other. Fig.16 In the example, four third switches 314a to 314d and four resistors Rop1 to Rop4 are provided. The plurality of third switches 314a to 314d are directly connected to the plurality of resistors Rop1 to Rop4 only via wiring. The plurality of third switches 314a to 314d are controlled by the external control circuit 4 (refer to Fig.14) receives an indication signal S1 for switching on / off of at least one of the plurality of third switches 314a to 314d. Among the plurality of third switches 314a to 314d, according to the third switch being turned on, at least one of the plurality of resistors Rop1 to Rop4 is connected to the source terminal of the NMOS-FET 312. Therefore, the value of the operating current Iop changes. For example, when only the third switch 314a is turned on, the operating current Iop has a constant current value obtained by dividing the voltage value of the input voltage Vop by the resistance value of the resistor Rop1. On the other hand, when the third switches 314a and 314c are turned on, the operating current Iop has a constant current value obtained by dividing the voltage value of the input voltage Vop by the combined resistance value of the resistors Rop1 and Rop3.

[0211] The external control circuit 4 switches the on / off state of at least one of the plurality of third switches 314a to 314d in sequence at a certain period (e.g., several kHz to several GHz). The switching order may be a predetermined order or a random order. For example, the external control circuit 4 switches the driving current I for each column of the plurality of iPM lasers 2 by switching the on / off state of at least one of the plurality of third switches 314a to 314d. out The external control circuit 4 can also switch the driving current I out The external control circuit 4 switches the plurality of third switches 314a to 314d in synchronization with the timing of switching the first switch 322a and the second switch 322b of each current mirror circuit 32. Thus, while driving the plurality of iPM lasers 2 individually, the driving currents I supplied to each of them are switched. out In other words, the switching operation of the first switch 322a and the second switch 322b is synchronized with the operation of changing the resistance value of the resistor portion Rop (the switching operation of the third switches 314a to 314d).

[0212] Refer again Fig.15. Each current mirror circuit 32 has a first current path 323 including a PMOS-FET 321a and a plurality of switch sections 322, and a second current path 324 including a PMOS-FET 321b. The first current path 323 is connected to the drain terminal of the NMOS-FET 312 of the current source circuit 31. The second current path 324 is connected to each iPM laser 2. When both the first switch 322a and the second switch 322b are turned on, the operating current Iop flows in the first current path 323. The gate terminal-source terminal voltage Vgs is common to the PMOS-FET 321a and the PMOS-FET 321b, so the operating current Iop also flows in the second current path 324. However, a driving current I obtained by amplifying the operating current Iop by N times (N is a real number) flows in the PMOS-FET 321b. out That is, the driving current I out Proportional to the size of the operating current Iop.

[0213] like Fig.15 As shown, each oscillation prevention circuit 33 includes an NMOS-FET 331, a first PMOS-FET 332, a second PMOS-FET 333, and an oscillation prevention switch section 334. The anode of each iPM laser 2 is connected to the source terminal of the NMOS-FET 331. The source terminal of the NMOS-FET 331 is also connected to the gate terminal of the first PMOS-FET 332. The source terminal of the first PMOS-FET 332 is connected to the drain terminal of the second PMOS-FET 333. The second PMOS-FET 333 supplies a current to the first PMOS-FET 332 according to the input voltage to the gate terminal of the second PMOS-FET 333. The potential between the first PMOS-FET 332 and the second PMOS-FET 333 is supplied to the gate terminal of the NMOS-FET 331. A feedback circuit is formed by the first PMOS-FET 332 and the second PMOS-FET 333. The drain terminal of the NMOS-FET 331 is connected to the voltage source 325 (the first constant potential line). The drain terminal of the first PMOS-FET 332 is connected to the reference potential line GND (the second constant potential line). The source terminal of the second PMOS-FET 333 is connected to the voltage source 325 (the third constant potential line). The oscillation prevention switch section 334 is connected between the anode of each iPM laser 2 and the source terminal of the NMOS-FET 331. The oscillation prevention switch section 334 includes a first oscillation prevention switch 334a and a second oscillation prevention switch 334b. The first oscillation prevention switch 334a and the second oscillation prevention switch 334b ​​are connected in series with each other. The first oscillation prevention switch 334a is connected to the first shift register 34a (refer to Fig.14) is electrically connected. The first oscillation prevention switch 334a is switched on / off according to the instruction signal S2 from the first shift register 34a. That is, the operation of the first oscillation prevention switch 334a is completely synchronized with the operation of the first switch 322a. The second oscillation prevention switch 334b ​​is connected to the second shift register 34b (refer to Fig.14 ) is electrically connected. The on / off of the second oscillation prevention switch 334b ​​is switched according to the instruction signal S3 from the second shift register 34b. That is, the operation of the second oscillation prevention switch 334b ​​is completely synchronized with the operation of the second switch 322b.

[0214] Each iPM laser 2 and the drain terminal of the PMOS-FET 321b are connected via a wiring 335 having an inductance. The first switch 322a, the second switch 322b, and the plurality of third switches 314a to 314d are switched at a cycle of, for example, several kHz to several GHz by an external control circuit 4. Therefore, when each switch is turned on / off, a resonance phenomenon associated with the inductance of the wiring 335 may cause peaking and ringing.

[0215] In each oscillation prevention circuit 33, the impedance of the NMOS-FET 331 has the effect of reducing the resonance constant Q through the effect of the feedback loop. That is, the impedance component of the NMOS-FET 331 enters the denominator of the resonance constant Q, so the resonance constant Q becomes smaller. In this way, each oscillation prevention circuit 33 can reduce the resonance constant Q, so the drive current I out Ringing and peaking are suppressed in the path through which the current flows. As a result, it is possible to suppress the generation of overcurrent and current overshoot in each iPM laser 2, and it is possible to drive the iPM laser 2 stably. The operation of the first oscillation prevention switch 334a is completely synchronized with the operation of the first switch 322a, and the operation of the second oscillation prevention switch 334b ​​is completely synchronized with the operation of the second switch 322b, thereby allowing the drain current to flow through the NMOS-FET 331 at the moment when the operating current Iop is supplied to each current mirror circuit 32. As a result, heat generation can be suppressed compared to the case where the drain current is always allowed to flow through the NMOS-FET 331.

[0216] Fig.17 Yes means Fig.14 1 is a diagram showing the structure of the switch operation unit 34. For the sake of convenience, a plurality of current mirror circuits 32 are arranged in a matrix with the X-axis direction and the Y-axis direction as the row direction and the column direction. Each current mirror circuit 32 is connected to each iPM laser 2, but Fig.17 In FIG. 1 , a plurality of iPM lasers 2 are not shown. The first shift register 34a has parallel outputs. Fig.17In the example of , the first shift register 34a has a four-terminal output consisting of output terminals 34a1 to 34a4, and the output terminals 34a1 to 34a4 are respectively connected to the columns of the plurality of current mirror circuits 32. The first shift register 34a drives the columns of the plurality of current mirror circuits 32 according to the instruction signal S2 from the external control circuit 4. Similarly, in Fig.17 In the example of FIG. 4 , the second shift register 34b has four output terminals 34b1 to 34b4, and the output terminals 34a1 to 34a4 are respectively connected to the rows of the plurality of current mirror circuits 32. The second shift register 34b drives the rows of the plurality of current mirror circuits 32 according to the instruction signal S3 from the external control circuit 4.

[0217] [Measurement method using a three-dimensional measuring device]

[0218] Fig.18 3D measuring device 10 is a schematic diagram showing the structure of the device. Fig.18 As shown, the three-dimensional measuring device 10 includes a semiconductor light emitting device 1 having a plurality of iPM lasers 2, a single imaging unit 50, and a measuring unit 60. Light L1 emitted from the plurality of iPM lasers 2 is irradiated to a certain area on the surface of the object to be measured SA placed on a workbench 7. The workbench 7 may also be a scanning workbench capable of scanning in a two-dimensional direction or a three-dimensional direction. When the irradiation range of the light L1 is sufficiently wide relative to the measurement range of the object to be measured SA, the configuration of the workbench 7 may also be omitted.

[0219] The imaging unit 50 is a device that is sensitive to the light L1 emitted from the plurality of iPM lasers 2. As the imaging unit 50, for example, a CCD (Charge Coupled Device) camera, a CMOS (Complementary MOS: Complementary Metal Oxide Semiconductor) camera, or other two-dimensional image sensors can be used. The imaging unit 50 captures the object SA being irradiated with the light L1, and outputs an output signal indicating the capturing result to the measuring unit 60.

[0220] The measuring unit 60 is, for example, a computer system including a processor, a memory, etc. The measuring unit 60 performs various control functions through the processor. As a computer system, for example, a personal computer, a microcomputer, a cloud server, a smart device (smartphone, tablet terminal, etc.) and the like can be cited. The measuring unit 60 can be composed of a PLC (Programmable logic controller) or an integrated circuit such as an FPGA (Field-programmable gate array).

[0221] For example, light L1 is formed as follows Fig.19 The sinusoidal fringe pattern W1 is shown. Fig.19 In the image, the light intensity in the stripe pattern W1 is represented by the shade of the color. The darker (closer to black) part has a greater light intensity, and the lighter (closer to white) part has a smaller light intensity. The stripe pattern W1 is, for example, a periodic stripe pattern represented by an image area of ​​100×100 pixels. The period of the stripe pattern W1 is, for example, a 20-pixel period. The brightness of the stripe pattern W1 changes according to the intensity of the light L1. The bright part (black part) in the stripe pattern W1 is a part where the intensity of the light L1 is strong, and the dark part (white part) in the stripe pattern W1 is a part where the intensity of the light L1 is weak.

[0222] The stripe pattern W1 is formed by combining a plurality of stripe elements formed by light beams outputted from a plurality of iPM lasers 2. Here, for simplicity of description, a case where four iPM lasers 2 are used to form the stripe pattern W1 with a four-pixel period is described as an example. Fig. 20 (a) is a diagram showing the first fringe element Wa formed by light output from a certain iPM laser 2 (hereinafter referred to as the first iPM laser). Fig. 20 (a) shows only the pattern of the first iPM laser output. The portion where the pattern is formed is represented by dots, and the greater the density of the dots, the greater the light intensity. Fig. 20 (b) is a diagram showing the second fringe element Wb formed by light output from another iPM laser 2 (hereinafter referred to as the second iPM laser). Fig. 20 (b) shows only the pattern of the second iPM laser output. Fig.21 (a) is a diagram showing a third fringe element Wc formed by light output from another iPM laser 2 (hereinafter referred to as the third iPM laser). Fig.21 (a) shows only the pattern of the 3rd iPM laser output. Fig.21 (b) is a diagram showing the fourth fringe element Wd formed by light output from yet another iPM laser 2 (hereinafter referred to as the fourth iPM laser). Fig.21 (b) shows only the pattern of the 4th iPM laser output. The light output from these iPM lasers 2 is included in the light L1. Fig. 20 (a) and Fig. 20 (b), the phase of the second stripe element Wb is offset from the phase of the first stripe element Wa by π / 2 (rad), that is, 1 / 4 period. In this example, the light intensity of the second stripe element Wb is greater than the light intensity of the first stripe element Wa. Fig. 20 (b) and Fig.21(a), the phase of the third stripe element Wc is shifted by π / 2 (rad) or 1 / 4 period relative to the phase of the second stripe element Wb. In addition, in this example, the light intensity of the third stripe element Wc is smaller than the light intensity of the second stripe element Wb. Fig.21 (a) and Fig.21 (b), the phase of the fourth stripe element Wd is shifted by π / 2, that is, 1 / 4 period, relative to the phase of the third stripe element Wc. In this example, the light intensity of the fourth stripe element Wd is smaller than the light intensity of the third stripe element Wc. Fig. 22 : is a graph showing the light intensity distribution of the stripe pattern W1 generated by synthesizing the first stripe element Wa to the fourth stripe element Wd. Fig. 22 In FIG. 1 , the horizontal axis represents the position in the direction intersecting the stripes (the periodic direction of the sine wave) (in other words, the phase of the stripe pattern W1), and the vertical axis represents the light intensity. Fig. 22 As shown, in the stripe pattern W1, by appropriately adjusting the light intensity of the first stripe element Wa to the fourth stripe element Wd, a pattern having a sinusoidal light intensity distribution is realized. Moreover, the more iPM lasers 2 there are (the more stripe elements there are), the closer to a correct sine wave. Fig. 22 Indicates two sine waves included in the stripe pattern W1.

[0223] When generating a stripe pattern W1 with a 4-pixel period, the first switch 322a and the second switch 322b of each current mirror circuit 32 connected to the first to fourth iPM lasers are turned on in the order of the first iPM laser, the second iPM laser, the third iPM laser, and the fourth iPM laser during the exposure period of one frame of the camera unit 50. In synchronization with the switching timing of the first switch 322a and the second switch 322b, the plurality of third switches 314a to 314d of the current source circuit 31 are switched in an arbitrary order. That is, each of the first to fourth iPM lasers is driven individually in sequence, while increasing or decreasing the driving current I supplied to each of them. out Thus, the 1st stripe element Wa, the 2nd stripe element Wb, the 3rd stripe element Wc and the 4th stripe element Wd respectively outputted from the 1st iPM laser, the 2nd iPM laser, the 3rd iPM laser and the 4th iPM laser are synthesized in one frame of shooting by the imaging unit 50 and are recognized as the stripe pattern W1 in the imaging unit 50.

[0224] The measuring unit 60 measures the three-dimensional shape of the object SA based on a phase shift method using the stripe pattern W1. In this method, for example, a plurality of sinusoidal stripe patterns W1 are used, each of which is given a phase shift (position shift) that divides the grid spacing into one period. The phase shift pattern only needs to prepare a pattern in which the phase is shifted by 2π / N (N is an integer).

[0225] Here, the case of using four sinusoidal stripe patterns W1 with different phase shifts is exemplified. If the light intensities of the four lights L1 each having four sinusoidal stripe patterns W1 are set to I0 to I3, respectively, and the pixels of the imaging unit 50 are set to (x, y), the light intensities I0 to I3 on ​​the surface of the object to be measured SA are expressed by the following equations (30) to (33). Ia(x, y) is the amplitude of the grid pattern, Ib(x, y) is the background intensity, and θ(x, y) is the initial phase.

[0226] [Math 30]

[0227] I0=Ia(x,y)cos{θ(x,y)}+Ib(x,y)...(30)

[0228] [Mathematical formula 31]

[0229] I1=Ia(x,y)cos{θ(x,y)+π / 2}+Ib(x,y)…(31)

[0230] [Math 32]

[0231] I2=Ia(x,y)cos{θ(x,y)+π}+Ib(x,y)…(32)

[0232] [Mathematical formula 33]

[0233] I3=Ia(x,y)cos{θ(x,y)+3π / 2}+Ib(x,y)…(33)

[0234] The initial phase θ can be obtained by tanθ=-(I3-I1) / (I2-I0). When the number of phase shifts of the sinusoidal fringe pattern W1 is N, the initial phase θ can be obtained by the following equation (34).

[0235] [Math 34]

[0236]

[0237] When such a phase shift method is used, by converting the measured phase into a height, the height of the object SA can be measured at intervals smaller than the pitch of the sinusoidal fringe pattern W1. In the structure of the three-dimensional measuring device 10, a plurality of iPM lasers 2 may be arranged in a direction parallel to the stripes in the sinusoidal fringe pattern W1. In this case, the phase shift caused by the positional offset of the plurality of iPM lasers 2 can be eliminated, and the offset of the initial phase of each of the plurality of sinusoidal fringe patterns W1 can be eliminated.

[0238] Here, a case where four sinusoidal stripe patterns having mutually different phases are used will be described. Fig.23 (a) is a diagram showing the first stripe pattern W11, Fig.23 (b) is a diagram showing the second stripe pattern W12, Fig.24 (a) is a diagram showing the third stripe pattern W13, Fig.24 (b) is a diagram showing the fourth stripe pattern W14. Fig.23 As shown in (a), the first stripe pattern W11 is a sinusoidal stripe pattern in which the light intensity of the first stripe element Wa is the largest and the light intensity of the third stripe element Wc is the smallest. Fig.23 As shown in (b), the second stripe pattern W12 is a sinusoidal stripe pattern in which the light intensity of the second stripe element Wb is the largest and the light intensity of the fourth stripe element Wd is the smallest. That is, from the first stripe pattern W11 to the second stripe pattern W12, a phase shift occurs in which the peak value of the light intensity moves along the direction in which the phase advances. Fig.24 As shown in (a), in the third stripe pattern W13, the light intensity of the third stripe element Wc is substantially equal to the light intensity of the second stripe element Wb. Furthermore, the light intensity of the fourth stripe element Wd is greater than the light intensity of the fourth stripe element Wd in the second stripe pattern W12. That is, a phase shift occurs from the second stripe pattern W12 to the third stripe pattern W13. Next, as Fig.24 As shown in (b), the fourth stripe pattern W14 is a sinusoidal stripe pattern in which the light intensity of the third stripe element Wc is the largest and the light intensity of the first stripe element Wa is the smallest. That is, a phase shift is generated from the third stripe pattern W13 to the fourth stripe pattern W14. As described above, a phase shift is continuously performed from the first stripe pattern W11 to the fourth stripe pattern W14. Thus, the three-dimensional shape of the object SA to be measured can be measured. Here, as an example of phase shift, four sinusoidal stripe patterns are shown, but when measuring using the phase shift method, an equally spaced phase shift is preferred.

[0239] [Function and Effect]

[0240] In the semiconductor light emitting device 1, the switch operation unit 34 operates the plurality of switch units 322 individually, thereby supplying the drive current I to each iPM laser 2 corresponding to each of the plurality of switch units 322. out Assuming that a plurality of current source circuits 31 corresponding to the iPM lasers 2 are provided, in the current source circuits 31 corresponding to the iPM lasers 2 that are not driven, the current source circuits 31 themselves are also driven, so power consumption (standby power) is generated. In the semiconductor light emitting device 1, the driving current I is supplied based on the operating current Iop generated by the common current source circuit 31. out, so the heat generated by the standby power can be reduced, and low power consumption can be achieved. In addition, since the current source circuit 31 is shared, the number of current source circuits 31 is small, so the semiconductor light emitting device 1 can be miniaturized.

[0241] In the semiconductor light emitting device 1, each of the plurality of switch sections 322 includes a first switch 322a and a second switch 322b connected in series with the first switch 322a. The switch operation section 34 includes a first shift register 34a for operating the first switch 322a and a second shift register 34b for operating the second switch 322b. Thus, the driving current I can be supplied only to the iPM laser 2 in which both the first switch 322a and the second switch 322b are turned on. out Furthermore, the first shift register 34a can specify the iPM laser 2 to be driven in units of, for example, rows, and the second shift register 34b can specify the iPM laser 2 to be driven in units of, for example, columns. Thus, it is easy to supply the driving current I to multiple iPM lasers 2 arranged in multiple rows and columns individually. out .

[0242] In the semiconductor light emitting device 1, the driving circuit 3 further includes a plurality of current mirror circuits 32 corresponding to the plurality of iPM lasers 2. Each of the plurality of current mirror circuits 32 includes a first current path 323 and a second current path 324 through which a current having a magnitude proportional to the magnitude of the current flowing through the first current path 323 flows. The first current path 323 is connected to the common current source circuit 31, the switch section 322 is provided on the first current path 323, and the second current path 324 is connected to the iPM laser 2 corresponding to the current mirror circuit 32 among the plurality of iPM lasers 2. Thus, the driving current I based on the operating current Iop generated by the common current source circuit 31 can be out The current is supplied to the iPM laser 2 via the second current path 324 .

[0243] In the semiconductor light emitting device 1, the driving circuit 3 further includes a plurality of oscillation prevention circuits 33 corresponding to the plurality of iPM lasers 2, respectively. Each of the plurality of oscillation prevention circuits 33 includes an NMOS-FET 331 including a source terminal connected to each anode terminal of the plurality of iPM lasers 2 and a drain terminal connected to the voltage source 325. Each of the plurality of oscillation prevention circuits 33 includes a first PMOS-FET 332 including a gate terminal connected to the source terminal of the NMOS-FET 331 and a drain terminal connected to a reference potential line GND having a lower potential than the voltage source 325. Each of the plurality of oscillation prevention circuits 33 includes a second PMOS-FET 333 including a drain terminal connected to the source terminal of the first PMOS-FET 332, a source terminal connected to the voltage source 325 having a higher potential than the reference potential line GND, and a gate terminal, and a current is supplied to the first PMOS-FET 332 according to an input voltage to the gate terminal. The potential between the first PMOS-FET 332 and the second PMOS-FET 333 is supplied to the gate terminal of the NMOS-FET 331. Thus, the resonance constant (Q value) can be reduced by providing the oscillation prevention circuit 33. Thus, ringing and peaking can be suppressed, and the iPM laser 2 can be driven stably.

[0244] In the semiconductor light emitting device 1, the value of the operating current Iop generated by the common current source circuit 31 is variable. out The size of is variable, and the light amount of each iPM laser 2 is changed. As a result, the brightness of the light images output from the plurality of iPM lasers 2 can be changed.

[0245] In the semiconductor light emitting device 1, the common current source circuit 31 also has: an operational amplifier 311, which supplies an input voltage Vop to one of a pair of input terminals; an NMOS-FET 312, which has a control terminal connected to the output terminal of the operational amplifier 311; and a resistor Rop, one end of which is connected to the current terminal of the NMOS-FET 312 and the other input terminal of the operational amplifier 311, and the other end is connected to the reference potential line GND. The resistance value of the resistor Rop is variable, and the switching action of the plurality of switch portions 322 is synchronized with the action of changing the resistance value of the resistor Rop. Thus, by making the resistance value of the resistor Rop variable, the value of the operating current Iop generated by the current source circuit 31 changes. Furthermore, by synchronizing the switching action of the plurality of switch portions 322 with the action of changing the resistance value of the resistor Rop, the driving current I supplied to each iPM laser 2 can be set for each iPM laser 2. out The value of .

[0246] In the semiconductor light emitting device 1, the resistor portion Rop includes a plurality of partial circuits 316a to 316d connected in parallel to each other between one end and the other end of the resistor portion Rop. The plurality of partial circuits 316a to 316d respectively include resistors Rop1 to Rop4 and third switches 314a to 314d connected in series to each other between one end and the other end of the resistor portion Rop. The switching action of the plurality of switch portions 322 is synchronized with the switching action of the third switches 314a to 314d. Thus, the resistance value of the resistor portion Rop can be made variable, and the switching action of the plurality of switch portions 322 is synchronized with the action of changing the resistance value of the resistor portion Rop.

[0247] In the semiconductor light emitting device 1, each of the plurality of iPM lasers 2 includes an active layer 22 as a light emitting portion, a phase modulation layer 25A optically coupled to the active layer 22, a first cladding layer 21 located on the first surface 2a side of the active layer 22 and the phase modulation layer 25A, a second cladding layer 23 located on the second surface 2b side of the active layer 22 and the phase modulation layer 25A, a second electrode 26 located on the second surface 2b side of the second cladding layer 23, and a first electrode 27 located on the first surface 2a side of the first cladding layer 21. The phase modulation layer 25A includes a basic layer 25a and a plurality of different refractive index regions 25b provided in the basic layer 25a in a manner distributed two-dimensionally on a surface perpendicular to the normal direction of the first surface 2a and having a refractive index different from that of the basic layer 25a. In a state where an imaginary square lattice is set on the surface, the plurality of different refractive index regions 25b are arranged in a state where the center of gravity G of each of the plurality of different refractive index regions 25b is separated from the corresponding lattice point by a distance r(x, y) (predetermined distance). Furthermore, the angle φ(x, y) around each lattice point in the imaginary square lattice, i.e., the angle φ(x, y) of the line segment connecting the center of gravity G of each of the plurality of different refractive index regions 25b and the corresponding lattice point relative to the imaginary square lattice, is set according to the phase distribution for forming the optical image, and at least two of the angles φ(x, y) in the plurality of different refractive index regions 25b are different from each other. Thus, the iPM laser 2 can be properly realized.

[0248] In the semiconductor light emitting device 1, the phase modulation layer 25B of the modified example includes: a basic layer 25a; and a plurality of different refractive index regions 25b, which are arranged in the basic layer 25a in a two-dimensionally distributed manner on a surface perpendicular to the normal direction of the first surface 2a, and have a refractive index different from the refractive index of the basic layer 25a. Moreover, in a state where an imaginary square lattice is set on the surface, the plurality of different refractive index regions 25b are arranged in a manner such that the center of gravity G of each of the plurality of different refractive index regions 25b is located on a straight line D passing through the corresponding lattice point and inclined to the imaginary square lattice, and the distance r(x, y) between the center of gravity G of each of the plurality of different refractive index regions 25b and the corresponding lattice point along the straight line D is set according to the phase distribution for forming the light image. Moreover, the slope of the straight line D, that is, the inclination angle θ, is uniform (consistent) in the plurality of different refractive index regions 25b. Thus, an iPM laser can be properly realized.

[0249] In the semiconductor light emitting device 1, the driving circuit 3 is connected to the plurality of iPM lasers 2 by bump bonding. Thus, the driving circuit 3 and the plurality of iPM lasers 2 can be integrated, and the device can be further miniaturized.

[0250] In the semiconductor light emitting device 1, the plurality of iPM lasers 2 are formed as a single chip. Thus, the plurality of iPM lasers 2 can be formed in a single element, and the semiconductor light emitting device 1 can be easily assembled.

[0251] [Modifications]

[0252] The present invention is not limited to the above-mentioned embodiments. Fig.25 (a) is a diagram showing a portion of the driving circuit 3A of the first variant. Below, only the points in the driving circuit 3A that are different from the driving circuit 3 in the embodiment are described. The driving circuit 3A includes a current source circuit 31A, a digital-to-analog converter 317, and a serial-to-parallel converter 318. In the current source circuit 31A, the source terminal of the NMOS-FET312 is connected to the resistor part Rop. One end of the resistor part Rop is connected to the source terminal of the NMOS-FET312 and the inverting input terminal of the operational amplifier 311, and the other end of the resistor part Rop is connected to the reference potential line GND. A digital-to-analog converter 317 is connected to the non-inverting input terminal of the operational amplifier 311, and a serial-to-parallel converter 318 is also connected to the digital-to-analog converter 317. In the current source circuit 31A, the resistance value of the resistor part Rop can be variable in the same way as in the above-mentioned embodiment, or it can be fixed.

[0253] The serial-to-parallel converter 318 receives a serial signal S4 from an external control circuit provided outside the semiconductor light-emitting device 1. The serial signal S4 includes an indication signal S2 for the first shift register 34a, an indication signal S3 for the second shift register 34b, and an indication signal S5 for setting the input voltage Vop. In other words, the indication signal S5 is a signal indicating an indication value of the current amount for the common current source circuit 31. The indication signals S2 and S3 are, for example, digital data marked with a 4-bit binary number, and the indication signal S5 is, for example, digital data marked with an 8-bit to 12-bit binary number. At this time, the serial signal S4 includes 16-bit to 20-bit digital data. The number of wirings between the external control circuit and the serial-to-parallel converter 318 is, for example, about 3. In addition to the wiring for transmitting the serial signal S4, wirings for sending a clock signal and a synchronization signal are also required, for example. The serial-to-parallel converter 318 converts the serial signal S4 into a parallel signal S6 including the indication signals S2, S3, and S5. The serial-to-parallel converter 316 outputs the instruction signal S2 among the parallel signals S6 to the first shift register 34 a , and outputs the instruction signal S3 among the parallel signals S6 to the second shift register 34 b .

[0254] The serial-to-parallel converter 318 outputs the indication signal S5 in the parallel signal S6 to the digital-to-analog converter 317. The number of wirings between the serial-to-parallel converter 318 and the digital-to-analog converter 317 is determined according to the number of bits of the indication signal S5, for example, 8 to 12. The digital-to-analog converter 317 converts the indication signal S5 from digital data into an analog signal, namely, an input voltage Vop, and then outputs the input voltage Vop to the non-inverting input terminal of the operational amplifier 311. The current source circuit 31A generates an operating current Iop having a magnitude corresponding to the indication signal S5 based on the input voltage Vop input. In the current source circuit 31A, the indication signal S5 changes synchronously with the switching timing of the first switch 322a and the second switch 322b. In other words, the switching action of the first switch 322a and the second switch 322b is synchronized with the action of switching the value of the input voltage Vop. Thus, a driving current I is set for each iPM laser 2. out The value of .

[0255] As described above, the driving circuit 3A of the first variant example has: a serial-to-parallel converter 318 for converting a serial signal S4 including digital data indicating an indication value of a current for the current source circuit 31A into a parallel signal S6; and a digital-to-analog converter 317 for converting the digital data converted into the parallel signal S6 into an analog signal. Then, the current source circuit 31A generates an operating current Iop having a magnitude corresponding to the indication value based on the analog signal (input voltage Vop). Thus, it is possible to receive digital data indicating an indication value of a current for the current source circuit 31A as a serial signal S4 from an external control circuit, so that the number of wirings connecting the semiconductor light emitting device 1 and the external control circuit can be reduced and the wiring can be made thinner, for example, to improve operability in three-dimensional measurement.

[0256] Fig.25 (b) is a diagram showing a current source circuit 31B of a second modified example. Hereinafter, only the differences between the current source circuit 31B and the current source circuit 31 of the above embodiment will be described. The current source circuit 31B does not have Fig.15 The voltage source 313 shown in FIG. 1 is used as the input voltage source 313. Instead, an input voltage Vop is supplied to the non-inverting input terminal of the operational amplifier 311 from an external control circuit provided outside the semiconductor light emitting device 1. Similar to the current source circuit 31A, the current source circuit 31B changes the magnitude of the input voltage Vop in synchronization with the switching timing of the first switch 322a and the second switch 322b. Thus, the drive current I out In the current source circuit 31B, the resistance value of the resistor Rop may be variable as in the above-mentioned embodiment, or may be fixed. According to the second variation, an analog signal representing an indication value of the current for the current source circuit 31B, i.e., an input voltage Vop, is input from an external control circuit, so that the number of wirings connecting the semiconductor light emitting device 1 to the external control circuit can be reduced and the wirings can be made thinner, for example, to improve workability in three-dimensional measurement.

[0257] Fig.26 FIG. 1 is a side view of a semiconductor light emitting device 1A according to a third variation. Fig.26 As shown, the semiconductor light emitting device 1A includes a supporting substrate 6. The supporting substrate 6 has a third surface 6a and a fourth surface 6b on the side opposite to the third surface 6a. The plurality of iPM lasers 2 are not monolithic structures as in the above-mentioned embodiment, but exist as individual chips, and are individually (individually) mounted on the third surface 6a in a manner that the second surface 2b is opposite to the third surface 6a. Adjacent iPM lasers 2 may be mounted at a certain interval, or may be installed without any interval. Fig.26In the example of , a plurality of iPM lasers 2 and a driving circuit 3 are arranged on a supporting substrate 6 that is shared with each other. Specifically, a plurality of iPM lasers 2 and a driving circuit 3 are arranged on the third surface 6a in a state of being arranged horizontally along the X-axis direction. The supporting substrate 6 contains wiring inside, and a plurality of electrodes 6c are arranged along the third surface 6a. Each iPM laser 2, each current mirror circuit 32 and a switch action unit 34 are electrically connected to the electrode 6c. That is, the electrical connection between the plurality of iPM lasers 2 and the driving circuit 3 is not performed by direct bump bonding as in the above-mentioned embodiment, but is performed via the wiring of the supporting substrate 6. The driving circuit 3 may also be arranged on the fourth surface 6b of the supporting substrate 6. That is, the plurality of iPM lasers 2 and the driving circuit 3 may also be arranged on the opposite side across the supporting substrate 6. According to the structure of the third variant, a plurality of iPM lasers 2 can be formed separately on the supporting substrate 6, and a plurality of iPM lasers 2 formed separately and the driving circuit 3 can be integrated on the supporting substrate 6, and similarly to the above-mentioned embodiment, the device can be miniaturized.

[0258] Fig. 27 1 is a side view of a semiconductor light emitting device 1B according to a fourth variation. In this example, as in the above embodiment, a plurality of iPM lasers 2 are formed as a single chip. The drive circuit 3 and the plurality of iPM lasers 2 formed as a single chip are provided on a common support substrate 6. According to such a structure, the drive circuit 3 and the plurality of iPM lasers 2 formed as a single chip can be integrated on the common support substrate 6, and as in the above embodiment, the device can be miniaturized.

[0259] Fig.28 It is a part of the cross-sectional view of the semiconductor light emitting device 1K of the fifth modified example. In the semiconductor light emitting device 1K, a semiconductor region 2d and a plurality of iPM lasers 2 are formed on a semiconductor substrate 20. The periphery of the semiconductor region 2d and the periphery of each iPM laser 2 are covered by an insulating film 28. The wiring electrode 27b is formed from the upper surface of the semiconductor region 2d to the side surface of the semiconductor region 2d via the insulating film 28. The wiring electrode 27b is also continuously connected to the surface of the semiconductor substrate 20 from the side surface of the semiconductor region 2d. The second electrode 26 is formed on the second surface 2b side of each iPM laser 2. The height of the wiring electrode 27b formed on the upper surface of the semiconductor region 2d in the Z-axis direction is consistent with the height of the second electrode 26 in the Z-axis direction. As a result, since both the N electrode (wiring electrode 27b) and the P electrode (second electrode 26) can be arranged on the common surface of the semiconductor substrate 20, it becomes a method suitable for surface mounting. Furthermore, by using the wiring electrode 27 b , wire bonding which is required when using the first electrode 27 is no longer necessary.

[0260] Fig.29It is a part of the cross-sectional view of the semiconductor light emitting device 1L of the sixth variant. Only the differences from the semiconductor light emitting device 1K are described. The side of each iPM laser 2 is covered by the second electrode 26 via the insulating film 28. The second electrode 26 is formed on the second surface 2b side of each iPM laser 2. That is, each iPM laser 2 is shielded by the second electrode 26 over the entire circumference. As a result, it is possible to suppress the laser light generated in each iPM laser 2 from interfering with each adjacent iPM laser 2, suppress the laser mode disorder, and achieve stable laser oscillation. In the case of actively utilizing the interference of laser light, it is preferable not to shield the periphery of the iPM laser 2 by an electrode as in the semiconductor light emitting device 1K.

[0261] (Second embodiment)

[0262] Fig.30 It is an exploded perspective view showing the structure of a light source device 1C according to a second embodiment of the present invention. Fig.18 The three-dimensional measuring device 10 shown in the figure may also include the light source device 1C of this embodiment instead of the semiconductor light emitting device 1. That is, the light source device 1C of this embodiment is used for three-dimensional shape measurement based on the phase shift method. Fig.30 As shown, the light source device 1C includes a plurality of iPM lasers 2 (first light sources), a drive circuit 3, a semiconductor substrate 20, a semiconductor region 2d, and a first electrode 27. In the present embodiment, the plurality of iPM lasers 2 are arranged in a row in one dimension with the Y-axis direction as the column direction. In the illustrated example, four iPM lasers 2 are arranged along the Y-axis direction. As in the above-mentioned embodiment, the plurality of iPM lasers 2 are formed monolithically on the semiconductor substrate 20. The plurality of iPM lasers 2 are arranged in a direction intersecting the optical axis direction in such a manner that the optical axis directions (in other words, the thickness directions of the iPM lasers 2) are consistent. In the present embodiment, the optical axis directions of the iPM lasers 2 are consistent with the Z-axis direction, and the plurality of iPM lasers 2 are arranged in the Y-axis direction orthogonal to the Z-axis direction. As for the structures of the other plurality of iPM lasers 2, and the structures of the drive circuit 3, the semiconductor substrate 20, the semiconductor region 2d, and the first electrode 27, they are the same as those of the semiconductor light emitting device 1 of the above-mentioned embodiment, and therefore detailed descriptions thereof are omitted.

[0263] Fig.31 (a) Fig.31 (b) Fig.32 (a) and Fig.32(b) is a diagram schematically showing a situation in which light L1 including stripe elements Wa to Wd is projected from four iPM lasers 2 to a common projection area. Stripe elements Wa to Wd are the first pattern in the present embodiment. In each stripe element Wa to Wd, a plurality of bright lines (represented by dots in the figure) WL1 are periodically arranged along a direction D1 (first direction) intersecting the extension direction of the bright lines WL1. The intervals F between the plurality of bright lines WL1 of the stripe elements Wa to Wd are equal to each other in the stripe elements Wa to Wd (in other words, between the plurality of iPM lasers 2). In addition, the positions of the plurality of bright lines WL1 in the direction D1, based on the position of the optical axis of each iPM laser 2, are different between the plurality of iPM lasers 2. Fig.31 and Fig.32 In the example shown, the bright lines WL1 of the stripe elements Wa to Wd are shifted by π / 2 (rad), i.e., 1 / 4 period. When the number of iPM lasers 2 is n, the shift amount of the bright lines WL1 between the multiple iPM lasers 2 is 1 / n of the interval (period) of the bright lines WL1. The multiple iPM lasers 2 are arranged along the direction D2 (second direction) orthogonal to the direction D1. That is, the direction D2 is perpendicular to the direction D1. Fig.30 The Y-axis directions are shown to be consistent.

[0264] like Fig.31 As shown in (a), first, light L1 is projected from the iPM laser 2 (the first iPM laser) located at one end in the direction D2. Thus, fringe elements Wa are projected in the common projection area. Next, as shown in Fig.31 As shown in (b), light L1 is projected from iPM laser 2 (second iPM laser) located next to the first iPM laser in direction D2. As a result, stripe element Wb is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the first iPM laser and the second iPM laser, a position offset E11 in direction D2 is generated between the stripe elements Wa and Wb output from these iPM lasers 2. The size of the position offset E11 is equal to the optical axis spacing between the first iPM laser and the second iPM laser. On the other hand, the position of the bright line WL1 of the stripe element Wb in direction D1 becomes a prescribed position, that is, a position shifted by 1 / 4 period from the bright line WL1 of the stripe element Wa, and no position offset from the prescribed position occurs. Next, as shown Fig.32As shown in (a), light L1 is projected from iPM laser 2 (3rd iPM laser) located next to the 2nd iPM laser in direction D2. As a result, stripe element Wc is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the 1st to 3rd iPM lasers, a position offset E12 in direction D2 is generated between stripe elements Wa and Wc. The magnitude of the position offset E12 is equal to the sum of the optical axis spacings of the 1st to 3rd iPM lasers. On the other hand, the position of the bright line WL1 of the stripe element Wc in direction D1 becomes a prescribed position, that is, a position shifted by 1 / 2 period from the bright line WL1 of the stripe element Wa, and no position offset from the prescribed position occurs. Next, as Fig.32 As shown in (b), light L1 is projected from iPM laser 2 (4th iPM laser) located next to the 3rd iPM laser in direction D2. Thus, the stripe element Wd is projected in the common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the 1st iPM laser to the 4th iPM laser, a position offset E13 in the direction D2 is generated between the stripe elements Wa and Wd. The size of the position offset E13 is equal to the sum of the optical axis spacings of the 1st iPM laser to the 4th iPM laser. On the other hand, the position of the bright line WL1 of the stripe element Wd in the direction D1 becomes a prescribed position, that is, a position shifted by 3 / 4 of a period from the bright line WL1 of the stripe element Wa, and no offset from the prescribed position occurs.

[0265] Here, as a comparative example of the present embodiment, a case where a plurality of iPM lasers 2 are arranged along the direction D1 will be described. Fig.33 (a) Fig.33 (b) Fig.34 (a) and Fig.34 (b) is a diagram schematically showing a situation in which, in such a comparative example, the four iPM lasers 2 project light L1 including the fringe elements Wa to Wd onto a common projection area. Fig.33 As shown in (a), first, light L1 is projected from the iPM laser 2 (first iPM laser) located at one end in the direction D1. Thus, fringe elements Wa are projected in the common projection area. Fig.33As shown in (b), light L1 is projected from iPM laser 2 (second iPM laser) located next to the first iPM laser in direction D1. As a result, stripe element Wb is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the first iPM laser and the second iPM laser, a position offset E21 in direction D1 is generated between stripe elements Wa and Wb output from these iPM lasers 2. The size of the position offset E21 is equal to the optical axis spacing between the first iPM laser and the second iPM laser. This position offset E21 causes the bright line WL1 of the stripe element Wb to be offset from a predetermined position of the bright line WL1 of the stripe element Wb in direction D1, that is, from a position shifted by 1 / 4 period from the bright line WL1 of the stripe element Wa. Next, as shown in FIG. Fig.34 As shown in (a), light L1 is projected from iPM laser 2 (3rd iPM laser) located next to the 2nd iPM laser in direction D1. As a result, stripe element Wc is projected in a common projection area. At this time, a position offset E22 in direction D1 is generated between stripe elements Wa and Wc according to the arrangement pitch (optical axis spacing) of the 1st to 3rd iPM lasers. The magnitude of the position offset E22 is equal to the sum of the optical axis spacings of the 1st to 3rd iPM lasers. The position offset E22 causes the bright line WL1 of the stripe element Wc to be offset from a predetermined position of the bright line WL1 of the stripe element Wc in direction D1, that is, from a position shifted by 1 / 2 period from the bright line WL1 of the stripe element Wa. Next, as shown Fig.34 As shown in (b), light L1 is projected from iPM laser 2 (4th iPM laser) located next to the 3rd iPM laser in direction D1. Thus, the stripe element Wd is projected in the common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the 1st iPM laser to the 4th iPM laser, a position offset E23 in the direction D1 is generated between the stripe elements Wa and Wd. The size of the position offset E23 is equal to the sum of the optical axis spacings of the 1st iPM laser to the 4th iPM laser. This position offset E23 causes the bright line WL1 of the stripe element Wd to be offset from the specified position of the bright line WL1 of the stripe element Wd in direction D1, that is, from the position shifted by 3 / 4 of a period from the bright line WL1 of the stripe element Wa.

[0266] Fig.35 1 is a diagram for explaining the problem caused by the positional deviation of the bright line WL1 in the above-mentioned comparative example. Fig.35In , two iPM lasers 2 adjacent to each other are represented to represent a plurality of iPM lasers 2. The arrangement pitch of the two iPM lasers 2 adjacent to each other is set to dy, the distance from the first surface 2a of these iPM lasers 2 to the projection plane H is set to Z1, and the offset of the center angle of the fringe element between the two iPM lasers 2 adjacent to each other is set to dα. At this time, the offset dα of the center angle is geometrically expressed as the following mathematical formula (35) using the arrangement pitch dy and the distance Z1.

[0267] [Mathematical formula 35]

[0268]

[0269] Fig.36 This is a graph showing the relationship between the distance Z1 and the center angle deviation dα when the arrangement pitch dy is set to 0.25 mm in the mathematical formula (35). Fig.36 In FIG. 1 , the horizontal axis represents the distance Z1 (mm), and the vertical axis represents the deviation dα (degree) of the center angle. The following lists the values ​​of the deviation dα of the center angle with respect to the representative distance Z1.

[0270] Z1=1mm→dα=14.0°

[0271] Z1=5mm→dα=2.86°

[0272] Z1=10mm→dα=1.43°

[0273] Z1=50mm→dα=0.286°

[0274] Z1=100mm→dα=0.143°

[0275] Z1=500mm→dα=0.0286°

[0276] Z1=1m→dα=0.0143°

[0277] according to Fig.36 As can be seen from the above table, the smaller the distance Z1 is, the larger the offset dα of the center angle is. For example, when the distance Z1 is 50 mm, the offset dα of the center angle is 0.286° near the center of the stripe element (near the optical axis), but if the period of a typical stripe is set to 1°, the error of the offset is 28.6%. This value is equivalent to the offset of the stripe element once, for example, the offset from the position of the stripe element Wa to the position of the stripe element Wb. In this way, if the offset dα of the center angle becomes larger, the error in forming the stripe pattern W1 becomes larger, and the measurement error in the three-dimensional shape measurement becomes larger. Depending on the purpose of the light source device 1C (for example, obtaining a stereoscopic image of the oral cavity in dentistry, etc.), the distance Z1 has to be reduced, so it is expected to reduce the above-mentioned measurement error.

[0278] In order to solve the above problem, when a plurality of iPM lasers 2 are arranged along a direction D2 orthogonal to the direction D1 as in the present embodiment (see Fig.31 and Fig.32 ), the arrangement direction of the plurality of iPM lasers 2 is orthogonal to the arrangement direction of the bright lines WL1 of the fringe elements Wa to Wd. Therefore, even if positional offsets E11 to E13 occur between the plurality of fringe elements Wa to Wd, the positional offsets E11 to E13 do not affect the formation of the fringe pattern W1. Therefore, compared with the above-mentioned comparative example, the measurement error in the three-dimensional shape measurement can be reduced.

[0279] In the light source device 1C of the present embodiment, the intervals F between the bright lines WL1 of the fringe elements Wa to Wd are equal among the plurality of iPM lasers 2, and the positions of the bright lines WL1 in the direction D1 based on the optical axis of each iPM laser 2 are different among the plurality of iPM lasers 2. By projecting such fringe elements Wa to Wd from the plurality of iPM lasers 2 to a common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0280] As in the present embodiment, the light source device 1C may also include a plurality of iPM lasers 2 as the first light source. In this case, the light source that outputs the light L1 including the stripe elements Wa to Wd can be miniaturized, and the light source device 1C can be miniaturized. The first light source is not limited to the iPM laser 2. As long as the first light source can project the light L1 including the stripe elements Wa to Wd periodically arranged along the direction D1 including a plurality of bright lines WL1, it may be another element (for example, an element formed by combining a semiconductor laser and a diffraction grating element (DOE)).

[0281] As in the present embodiment, a plurality of iPM lasers 2 may be formed as a single chip. In this case, a plurality of iPM lasers 2 can be formed in a single element, making it easier to assemble the light source device 1C.

[0282] As in the present embodiment, the number of the plurality of iPM lasers 2 may be n, and the shift amount of the bright line WL1 between the plurality of iPM lasers 2 may be 1 / n of the interval F between the bright lines WL1. In this case, Fig.19 The fringe pattern W1 shown can suitably perform three-dimensional shape measurement using the phase shift method.

[0283] Fig.37 (a) Fig.37 (b) Fig.38 (a) and Fig.38(b) is a diagram for illustrating a variation of the second embodiment, schematically showing a situation where light L1 including each of the stripe patterns W1a to W1d is projected from four iPM lasers 2 onto a common projection area. The stripe patterns W1a to W1d are the first pattern in this variation. In these figures, the light intensity of the stripe patterns W1a to W1d is represented by the light intensity of the color, where the greater the light intensity, the darker it is, and the smaller the light intensity, the lighter it is. In each of the stripe patterns W1a to W1d, a plurality of bright lines WL2 are periodically arranged along a direction D1 that intersects the extension direction of the bright lines WL2. The stripe patterns W1a to W1d are preferably, for example, Fig.19 The light intensity may be a pattern that changes sinusoidally along the direction D1 as shown in FIG. 1 , but it may not be a sinusoidal wave like the top hat type. That is, in this modification, the phase of the fringe pattern of each iPM laser 2 is shifted for each iPM laser 2, while the fringe pattern is projected from each iPM laser 2 to the measurement object, and each time the fringe pattern is projected from each iPM laser 2, an image is taken, thereby performing three-dimensional shape measurement based on the phase shift method. Except for the pattern output from the iPM laser 2, the structure of the light source device is the same as that of the second embodiment described above.

[0284] The intervals between the multiple bright lines WL2 of the stripe patterns W1a to W1d, i.e., the period of the bright lines WL2, are equal in the stripe patterns W1a to W1d (in other words, between the multiple iPM lasers 2). The positions, i.e., the phases, of the multiple bright lines WL2 in the direction D1 based on the position of the optical axis of each iPM laser 2 are different between the multiple iPM lasers 2. Fig.37 and Fig.38 In the example shown, the bright lines WL2 of the stripe patterns W1a to W1d are offset from each other by π / 2 (rad), i.e., 1 / 4 period. When the number of iPM lasers 2 is n, the shift amount of the bright lines WL2 between the multiple iPM lasers 2 is 1 / n of the interval (period) of the bright lines WL2. The phase modulation layer 25A or 25B of each iPM laser 2 has a phase distribution for outputting the stripe patterns W1a to W1d as described above. The multiple iPM lasers 2 are arranged along a direction D2 that is orthogonal to the direction D1, similarly to the second embodiment. That is, the direction D2 is perpendicular to the direction D1. Fig.30 The Y-axis directions are shown to be consistent.

[0285] like Fig.37 As shown in (a), first, light L1 is projected from the iPM laser 2 (the first iPM laser) located at one end in the direction D2. Thus, a stripe pattern W1a is projected in the common projection area. Next, as shown in Fig.37As shown in (b), light L1 is projected from iPM laser 2 (second iPM laser) located next to the first iPM laser in direction D2. As a result, stripe pattern W1b is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the first iPM laser and the second iPM laser, a position offset E11 in direction D2 is generated between stripe patterns W1a and W1b output from these iPM lasers 2. On the other hand, the position of bright line WL2 of stripe pattern W1b in direction D1 becomes a prescribed position, that is, a position shifted by 1 / 4 period from bright line WL2 of stripe pattern W1a, and no position offset from the prescribed position occurs. Next, as shown Fig.38 As shown in (a), light L1 is projected from iPM laser 2 (3rd iPM laser) located next to the 2nd iPM laser in direction D2. As a result, stripe pattern W1c is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the 1st to 3rd iPM lasers, a position offset E12 in direction D2 occurs between stripe patterns W1a and W1c. On the other hand, the position of bright line WL2 of stripe pattern W1c in direction D1 becomes a prescribed position, that is, a position shifted by 1 / 2 cycle from bright line WL2 of stripe pattern W1a, and no position offset from the prescribed position occurs. Next, as shown Fig.38 As shown in (b), light L1 is projected from iPM laser 2 (the 4th iPM laser) located next to the 3rd iPM laser in the direction D2. Thus, the stripe pattern W1d is projected in the common projection area. At this time, a positional offset E13 in the direction D2 is generated between the stripe patterns W1a and W1d according to the arrangement pitch (optical axis spacing) of the 1st to 4th iPM lasers. On the other hand, the position of the bright line WL2 of the stripe pattern W1d in the direction D1 becomes a predetermined position, that is, a position shifted 3 / 4 of a period from the bright line WL2 of the stripe pattern W1a, and no positional offset from the predetermined position is generated.

[0286] Here, as a comparative example of this modification, a case where a plurality of iPM lasers 2 are arranged along the direction D1 will be described. Fig.39 (a) Fig.39 (b) Fig.40 (a) and Fig.40 (b) is a diagram schematically showing a situation in which, in such a comparative example, the four iPM lasers 2 project the light L1 including the stripe patterns W1a to W1d onto a common projection area. Fig.39 As shown in (a), first, light L1 is projected from the iPM laser 2 (first iPM laser) located at one end in the direction D1. Thus, a stripe pattern W1a is projected in the common projection area. Next, as shown in Fig.39As shown in (b), light L1 is projected from iPM laser 2 (second iPM laser) located next to the first iPM laser in direction D1. As a result, stripe pattern W1b is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the first iPM laser and the second iPM laser, a position offset E21 in direction D1 is generated between stripe patterns W1a and W1b output from these iPM lasers 2. This position offset E21 causes the bright line WL2 of stripe pattern W1b to be offset from a predetermined position of the bright line WL2 of stripe pattern W1b in direction D1, that is, from a position offset by 1 / 4 period from the bright line WL2 of stripe pattern W1a. Next, as shown in Fig.40 As shown in (a), light L1 is projected from iPM laser 2 (3rd iPM laser) located next to the 2nd iPM laser in direction D1. As a result, stripe pattern W1c is projected in a common projection area. At this time, a position offset E22 in direction D1 is generated between stripe patterns W1a and W1c according to the arrangement pitch (optical axis spacing) of the 1st to 3rd iPM lasers. This position offset E22 causes the bright line WL2 of stripe pattern W1c to be offset from a predetermined position of the bright line WL2 of stripe pattern W1c in direction D1, that is, from a position shifted by 1 / 2 period from the bright line WL2 of stripe pattern W1a. Next, as shown in Fig.40 As shown in (b), light L1 is projected from iPM laser 2 (the 4th iPM laser) located next to the 3rd iPM laser in the direction D1. As a result, the stripe pattern W1d is projected in the common projection area. At this time, a position offset E23 in the direction D1 is generated between the stripe patterns W1a and W1d according to the arrangement pitch (optical axis spacing) of the 1st to 4th iPM lasers. This position offset E23 causes the bright line WL2 of the stripe pattern W1d to be offset from the specified position of the bright line WL2 of the stripe pattern W1d in the direction D1, that is, from the position offset by 3 / 4 period from the bright line WL2 of the stripe pattern W1a. In the comparative example, due to the position offset of the bright line WL2, the offset accuracy of the phases of the stripe patterns W1b to W1d is reduced, and the measurement error becomes larger.

[0287] In view of the above problem, when a plurality of iPM lasers 2 are arranged along a direction D2 orthogonal to the direction D1 as in this modification (see Fig.37 and Fig.38 ), the arrangement direction of the plurality of iPM lasers 2 is orthogonal to the arrangement direction of the bright lines WL2 of the stripe patterns W1a to W1d. Therefore, even if positional offsets E11 to E13 occur between the plurality of stripe patterns W1a to W1d, the positional offsets E11 to E13 do not affect the phase offset accuracy of the stripe patterns W1b to W1d. Therefore, compared with the above-mentioned comparative example, the measurement error in the three-dimensional shape measurement can be reduced.

[0288] In this modified example, the intervals (periods) of the bright lines WL2 of the stripe patterns W1a to W1d are equal among the multiple iPM lasers 2, and the positions (phases) of the bright lines WL2 in the direction D1 based on the optical axes of the respective iPM lasers 2 are different among the multiple iPM lasers 2. By projecting such stripe patterns W1a to W1d from the multiple iPM lasers 2 to a common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0289] Fig.41 (a) Fig.41 (b) Fig.42 (a) and Fig.42 (b) is a diagram for illustrating another variant of the second embodiment, schematically showing a situation where light L1 including each of the stripe patterns W2a to W2d is projected from four iPM lasers 2 onto a common projection area. The stripe patterns W2a to W2d are the first pattern in this variant. In these figures, the light intensity of the stripe patterns W2a to W2d is represented by the shade of the color, the smaller the light intensity, the lighter (white), and the larger the light intensity, the darker (black). In each of the stripe patterns W2a to W2d, a plurality of bright lines WL3 are arranged along a direction D1 that intersects the extension direction of the bright lines WL3. The stripe patterns W2a to W2d each include a Gray code pattern. That is, the width and position of the bright line WL3 represent the Gray code. In this modification, the fringe pattern is projected onto the object to be measured from each iPM laser 2 while changing the Gray code included in the fringe pattern of each iPM laser 2 for each iPM laser 2, and a three-dimensional shape measurement is performed by taking an image for each projection of the fringe pattern from each iPM laser 2. The structure of the light source device is the same as that of the second embodiment described above, except for the pattern output from the iPM laser 2.

[0290] Gray code is one of the methods of expressing binary numbers. Fig.43 This is a chart showing the conversion between binary code, which is another way to express decimal numbers and binary numbers, and Gray code. Gray code has the characteristic that it only changes by 1 bit when the number increases or decreases by 1. Since the change is only 1 bit, it is difficult to cause malfunction, and it is often used in digital circuits, etc. Fig.44 2 is a diagram showing an example of a combination of stripe patterns including a 4-bit Gray code. This diagram shows the brightness of each of a plurality of bits arranged along the direction D1. Fig.44As an example, a stripe pattern W2a to W2d containing 4 different Gray codes is shown. The conversion from binary code to Gray code follows the following rules. First, the most significant bit 1 of the Gray code is the same as the binary code. After that, refer to the adjacent 2 bits in sequence from the high bit. If 1 or 0 is continuous, the corresponding bit of the Gray code is set to 0. If it is not continuous, the corresponding bit of the Gray code is set to 1. Alternatively, the conversion from binary code to Gray code can also follow the following rules. First, prepare the binary code of the object. Then, shift the binary code to the right by 1 bit, and find the binary code with 0 appended to its beginning. Then, obtain the exclusive OR of the binary code and the original binary code. The result of the operation is Gray code. For example, Gray code can be generated using OpenCV.

[0291] In Gray code, the Hamming distance between adjacent bits is 1. The Hamming distance refers to the number of bits of different values ​​located at corresponding positions when comparing two values ​​with the same number of bits. Therefore, in Gray code with a Hamming distance of 1, even if a bit error occurs when restoring a bit string, the error is within 1. In binary code, the error of the position becomes larger when an error occurs in a high bit, but in Gray code, a code resistant to noise is obtained.

[0292] The stripe patterns W2a to W2d are stripe-shaped patterns set to have different Gray code values. By sequentially switching these four stripe patterns W2a to W2d and capturing them with the imaging unit 50, the three-dimensional shape of the object SA can be measured.

[0293] In order to avoid misidentification due to the color of the surface of the object to be measured SA, a method including Fig.44 The stripe patterns W2a to W2d shown are stripe patterns of other Gray codes after the bit values ​​of the Gray codes are inverted. In this case, four iPM lasers 2 for outputting stripe patterns including other Gray codes may be further provided.

[0294] The plurality of iPM lasers 2 are arranged along a direction D2 that is orthogonal to the direction D1, similarly to the second embodiment. Fig.30 The Y-axis directions are shown to be consistent.

[0295] by Fig.44 Taking the stripe patterns W2a to W2d in FIG. 1 as an example, the operation of switching four stripe patterns in sequence is described. Fig.41 As shown in (a), first, light L1 is projected from the iPM laser 2 (the first iPM laser) located at one end in the direction D2. Thus, a stripe pattern W2a is projected in the common projection area. Next, as shown in Fig.41As shown in (b), light L1 is projected from iPM laser 2 (second iPM laser) located next to the first iPM laser in direction D2. As a result, stripe pattern W2b is projected in a common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the first iPM laser and the second iPM laser, a position offset E11 in direction D2 is generated between the stripe patterns W2a and W2b output from these iPM lasers 2. On the other hand, the position of the bright line WL3 that does not generate the stripe pattern W2b in direction D1 is offset from the specified position. Next, as shown in Fig.42 As shown in (a), light L1 is projected from iPM laser 2 (3rd iPM laser) located next to the 2nd iPM laser in direction D2. As a result, stripe pattern W2c is projected in the common projection area. At this time, according to the arrangement pitch (optical axis spacing) of the 1st to 3rd iPM lasers, a position offset E12 in direction D2 is generated between stripe patterns W2a and W2c. On the other hand, the position of bright line WL3 that does not generate stripe pattern W2c in direction D1 is offset from the specified position. Next, as shown in Fig.42 As shown in (b), light L1 is projected from iPM laser 2 (the 4th iPM laser) located next to the 3rd iPM laser in the direction D2. Thus, the stripe pattern W2d is projected in the common projection area. At this time, a positional offset E13 in the direction D2 is generated between the stripe patterns W2a and W2d according to the arrangement pitch (optical axis spacing) of the 1st to 4th iPM lasers. On the other hand, the position of the bright line WL3 that does not generate the stripe pattern W2d in the direction D1 is offset from the specified position.

[0296] When a plurality of iPM lasers 2 are arranged along a direction D2 orthogonal to the direction D1 as in this modification (see Fig.41 and Fig.42 ), the arrangement direction of the plurality of iPM lasers 2 is orthogonal to the arrangement direction of the bright lines WL3 of the stripe patterns W2a to W2d. Therefore, even if positional offsets E11 to E13 occur between the plurality of stripe patterns W2a to W2d, the positional offsets E11 to E13 do not affect the calculation of the three-dimensional shape. Therefore, the measurement error in the three-dimensional shape measurement can be reduced.

[0297] (Third embodiment)

[0298] Fig.45 and Fig.46 Each of the perspective views shows the structure of a light source device 1D and 1E according to a third embodiment of the present invention. Fig.45 The light source device 1D shown in FIG. Fig.46The light source device 1E shown has light source groups 201 and 202. The light source group 201 includes a plurality of (four in the example shown) iPM lasers 2A (first light source) arranged in a direction intersecting the optical axis direction in a manner that their respective optical axis directions are consistent. The light source group 202 includes a plurality of (four in the example shown) iPM lasers 2B (second light source) arranged in a direction intersecting the optical axis direction in a manner that their respective optical axis directions are consistent. The plurality of iPM lasers 2A and the plurality of iPM lasers 2B are formed as a single chip on a common semiconductor substrate 20. The internal structure of the iPM lasers 2A and 2B is the same as that of the iPM laser 2 of the first embodiment described above.

[0299] The plurality of iPM lasers 2A each include the above-mentioned fringe elements Wa to Wd (see Fig.31 and Fig.32 ), or each stripe pattern W1a~W1d (refer to Fig.37 and Fig.38 ) is projected onto a common projection area. The stripe elements Wa~Wd or stripe patterns W1a~W1d projected from the multiple iPM lasers 2A are the first pattern in the present embodiment. The multiple iPM lasers 2B respectively project the light containing the stripe elements Wa~Wd or the stripe patterns W1a~W1d onto the above-mentioned common projection area. The stripe elements Wa~Wd or stripe patterns W1a~W1d projected from the multiple iPM lasers 2B are the second pattern in the present embodiment. The multiple iPM lasers 2A are arranged along a direction D12 (equivalent to the above-mentioned direction D2) orthogonal to the arrangement direction D11 (equivalent to the above-mentioned direction D1) of the bright lines of the stripe elements Wa~Wd or the stripe patterns W1a~W1d, similarly to the multiple iPM lasers 2 in the second embodiment or its modified example. The plurality of iPM lasers 2B are arranged along a direction D22 (a fourth direction, equivalent to the above-mentioned direction D2) orthogonal to the arrangement direction D21 (a third direction, equivalent to the above-mentioned direction D1) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d. In the example shown in the figure, the directions D21 and D22 are respectively consistent with the directions D11 and D12, but the directions D21 and D22 may be different from the directions D11 and D12.

[0300] The stripe pattern W1 (see Fig.19 ) or the period of the stripe pattern W1a to W1d is different from the period of the stripe pattern W1 or the period of the stripe pattern W1a to W1d formed by the stripe elements Wa to Wd output from the light source group 201. Fig.45 In the light source device 1D shown in FIG. 1 , the light source group 201 and the light source group 202 are arranged in a direction intersecting the respective arrangement directions D12 and D22. Fig.46In the light source device 1E shown, the light source group 201 and the light source group 202 are arranged along respective arrangement directions D12 and D22.

[0301] The intervals (periods) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d are equal among the multiple iPM lasers 2A. The positions (phases) of the bright lines in the direction D11 based on the optical axis of each iPM laser 2A are different among the multiple iPM lasers 2A. Similarly, the intervals (periods) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d are equal among the multiple iPM lasers 2B. The positions (phases) of the bright lines in the direction D21 based on the optical axis of each iPM laser 2B are different among the multiple iPM lasers 2B. By projecting such stripe elements Wa to Wd or stripe patterns W1a to W1d from multiple iPM lasers 2A or 2B to a common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0302] In the light source devices 1D and 1E of the present embodiment, by using two light source groups, namely, a light source group 201 including a plurality of iPM lasers 2A and a light source group 202 including a plurality of iPM lasers 2B, at least two three-dimensional shape measurements using the phase shift method are performed, and the measurement accuracy can be improved. In the light source devices 1D and 1E of the present embodiment, the plurality of iPM lasers 2A are arranged along a direction D12 orthogonal to the arrangement direction D11 of the bright lines, and the plurality of iPM lasers 2B are arranged along a direction D22 orthogonal to the arrangement direction D21 of the bright lines. In this case, even if the positions of the iPM lasers 2A (or 2B) deviate from each other by the amount of the arrangement pitch, the direction of the deviation is orthogonal to the arrangement direction of the bright lines. Therefore, even if the positional deviation of the fringe elements Wa to Wd or the fringe patterns W1a to W1d occurs in the plurality of iPM lasers 2A (or 2B), the positional deviation does not affect the shift accuracy of the phase, etc. Therefore, according to the light source devices 1D and 1E of the present embodiment, the measurement error in the three-dimensional shape measurement using the phase shift method can be reduced.

[0303] As in the present embodiment, the interval (period) of bright lines of the stripe pattern W1 or the stripe pattern W1a to W1d formed by the stripe elements Wa to Wd output from the light source group 202 may be different from the interval (period) of bright lines of the stripe pattern W1 or the stripe pattern W1a to W1d formed by the stripe elements Wa to Wd output from the light source group 201. In this case, the three-dimensional shape measurement using the phase shift method can be performed using two stripe patterns having different intervals of bright lines, so that the measurement accuracy can be further improved.

[0304] [Modifications]

[0305] Fig.47It is a perspective view showing the structure of a light source device 1F according to a modified example of the third embodiment. Fig.47 The light source device 1F shown has light source groups 203 and 204 in addition to the light source groups 201 and 202 of the third embodiment. The light source group 203 includes a plurality of (four in the example shown) iPM lasers 2C (second light source) arranged in a direction intersecting the optical axis direction in a manner that their respective optical axis directions are consistent. The light source group 204 includes a plurality of (four in the example shown) iPM lasers 2D (second light source) arranged in a direction intersecting the optical axis direction in a manner that their respective optical axis directions are consistent. The plurality of iPM lasers 2C and the plurality of iPM lasers 2D are formed as a single chip on a common semiconductor substrate 20 together with the plurality of iPM lasers 2A and the plurality of iPM lasers 2B. The internal structure of the iPM lasers 2C and 2D is the same as that of the iPM laser 2 of the first embodiment described above.

[0306] The plurality of iPM lasers 2C each include the above-mentioned fringe elements Wa to Wd (see Fig.31 and Fig.32 ), or each stripe pattern W1a~W1d (refer to Fig.37 and Fig.38 ) is projected onto a common projection area. The stripe elements Wa~Wd or stripe patterns W1a~W1d projected from multiple iPM lasers 2C are the second pattern in this modification. Multiple iPM lasers 2D respectively project light containing stripe elements Wa~Wd or stripe patterns W1a~W1d onto the above-mentioned common projection area. The stripe elements Wa~Wd or stripe patterns W1a~W1d projected from multiple iPM lasers 2D are the second pattern in this modification. Multiple iPM lasers 2C are arranged along a direction D32 (a fourth direction, equivalent to the above-mentioned direction D2) orthogonal to the arrangement direction D31 (a third direction, equivalent to the above-mentioned direction D1) of the bright lines of the stripe elements Wa~Wd or the stripe patterns W1a~W1d. A plurality of iPM lasers 2D are arranged along a direction D42 (a fourth direction, equivalent to the above-mentioned direction D2) orthogonal to the arrangement direction D41 (a third direction, equivalent to the above-mentioned direction D1) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d. In the example shown in the figure, directions D41 and D42 are respectively consistent with directions D31 and D32, but directions D41 and D42 may also be different from directions D31 and D32. Directions D31 and D41 intersect with directions D11 and D21. In the example shown in the figure, directions D31 and D41 are orthogonal to directions D11 and D21, but directions D31 and D41 may also be inclined relative to directions D11 and D21.

[0307] The stripe pattern W1 (see Fig.19) or the period of the stripe pattern W1a to W1d is different from the period of the stripe pattern W1 or the period of the stripe pattern W1a to W1d formed by the stripe elements Wa to Wd output from the light source group 204. Fig.47 In the light source device 1F shown, the light source groups 203 and 204 are arranged in a direction intersecting the respective arrangement directions D32 and D42, but the light source groups 203 and 204 may be arranged along the respective arrangement directions D32 and D42.

[0308] The intervals (periods) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d are equal among the multiple iPM lasers 2C. The positions (phases) of the bright lines in the direction D31 based on the optical axis of each iPM laser 2C are different among the multiple iPM lasers 2C. Similarly, the intervals (periods) of the bright lines of the stripe elements Wa to Wd or the stripe patterns W1a to W1d are equal among the multiple iPM lasers 2D. The positions (phases) of the bright lines in the direction D41 based on the optical axis of each iPM laser 2D are different among the multiple iPM lasers 2D. By projecting such stripe elements Wa to Wd or stripe patterns W1a to W1d from multiple iPM lasers 2C or 2D to a common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0309] In the light source device 1F of this modification, the three-dimensional shape measurement using the phase shift method is performed at least four times by four light source groups, namely, a light source group 201 including a plurality of iPM lasers 2A, a light source group 202 including a plurality of iPM lasers 2B, a light source group 203 including a plurality of iPM lasers 2C, and a light source group 204 including a plurality of iPM lasers 2D, so that the measurement accuracy can be improved. In the light source device 1F of this modification, the plurality of iPM lasers 2C are arranged along a direction D32 orthogonal to the arrangement direction D31 of the bright lines, and the plurality of iPM lasers 2D are arranged along a direction D42 orthogonal to the arrangement direction D41 of the bright lines. In this case, even if the positions of the iPM lasers 2C (or 2D) are offset from each other by the amount of the arrangement pitch, the direction of the offset is orthogonal to the arrangement direction of the bright lines. Therefore, even if the positional offset of the fringe elements Wa to Wd or the fringe patterns W1a to W1d occurs in the plurality of iPM lasers 2C (or 2D), the positional offset does not affect the phase shift accuracy, etc. Therefore, according to the light source device 1F of this modification, it is possible to reduce the measurement error in the three-dimensional shape measurement using the phase shift method.

[0310] As in this modification, the interval (period) of bright lines of the stripe pattern W1 or the stripe pattern W1a~W1d formed by the stripe elements Wa~Wd output from the light source group 204 may be different from the interval (period) of bright lines of the stripe pattern W1 or the stripe pattern W1a~W1d formed by the stripe elements Wa~Wd output from the light source group 203. In this case, the three-dimensional shape measurement using the phase shift method can be performed using two stripe patterns with different intervals of bright lines, so the measurement accuracy can be further improved.

[0311] As in this modification, the arrangement direction D31 of the bright lines output from the multiple iPM lasers 2C and the arrangement direction D41 of the bright lines output from the multiple iPM lasers 2D may intersect with the arrangement direction D11 of the bright lines output from the multiple iPM lasers 2A and the arrangement direction D21 of the bright lines output from the multiple iPM lasers 2B. In this case, two or more fringe patterns with different arrangement directions of the bright lines can be used to perform three-dimensional shape measurement using the phase shift method, so that the measurement accuracy can be further improved.

[0312] (Fourth embodiment)

[0313] Fig.48 It is a perspective view showing the structure of a light receiving and emitting module 1G according to a fourth embodiment of the present invention. Fig.48 The light receiving and emitting module 1G shown in the figure has Fig.47 In addition to the structure of the light source device 1F shown in the figure, it also includes an imaging element 51. In the light receiving and emitting module 1G of this modified example, the light source groups 201 to 204 are arranged in a manner to surround the imaging element 51, which is different from the light source device 1F. Specifically, the light source groups 201 and 202 are arranged in the directions D11 and D21, and the imaging element 51 is arranged between them. The light source groups 203 and 204 are arranged in the directions D31 and D41, and the imaging element 51 is arranged between them. The structure of each light source group 201 to 204 is the same as that of the third embodiment and its modified example.

[0314] The imaging element 51 is provided on a substrate shared with the iPM lasers 2A to 2D. In one example, the imaging element 51 is formed monolithically on the semiconductor substrate 20 together with the iPM lasers 2A to 2D. Fig.18 The imaging element 51 is provided by the imaging unit 50 shown in FIG. The imaging element 51 is sensitive to the light L1 emitted from the iPM lasers 2A to 2D. The imaging element 51 captures the fringe elements Wa to Wd or the fringe patterns W1a to W1d in the object to be measured (projection area) irradiated with the light L1, generates image data representing the capturing result, and outputs the image data to the measuring unit 60 (see FIG. Fig.18 ).

[0315] The light receiving and emitting module 1G of this embodiment includes the light source device 1D and can achieve the same effects as the light source device 1D. The light receiving and emitting module 1G of this embodiment includes the light source device 1F and can achieve the same effects as the light source device 1F.

[0316] [Modifications]

[0317] Fig.49 1 is a perspective view showing the structure of a light receiving and emitting module 1H of a modified example of the fourth embodiment. In this modified example, the number of iPM lasers included in the light source groups 201 to 204 is three, and one of the plurality of iPM lasers included in each light source group 201 to 204 is included in the arrangement of another adjacent light source group.

[0318] Specifically, one iPM laser 2A located at the first end in the arrangement direction among the three iPM lasers 2A constituting the light source group 201 is located at the second end side of the three iPM lasers 2D constituting the light source group 204, and is arranged in a row with these iPM lasers 2D. Similarly, one iPM laser 2D located at the first end in the arrangement direction among the three iPM lasers 2D constituting the light source group 204 is located at the second end side of the three iPM lasers 2B constituting the light source group 202, and is arranged in a row with these iPM lasers 2B. One iPM laser 2B located at the first end in the arrangement direction among the three iPM lasers 2B constituting the light source group 202 is located at the second end side of the three iPM lasers 2C constituting the light source group 203, and is arranged in a row with these iPM lasers 2C. One iPM laser 2C located at the first end in the arrangement direction among the three iPM lasers 2C constituting the light source group 203 is located on the second end side of the three iPM lasers 2A constituting the light source group 201 and is arranged in a row with these iPM lasers 2A.

[0319] According to the structure of this modification, the light source groups 201 to 204 can be densely arranged, which contributes to the miniaturization of the light receiving and emitting module.

[0320] Fig.50 1 is a perspective view showing the structure of a light receiving and emitting module 1J of another modified example of the fourth embodiment. This modified example is different from the fourth embodiment in the arrangement of the light source groups 201 to 204. That is, in this modified example, the light source groups 201 to 204 do not surround the imaging element 51, and are not connected to the imaging element 51. Fig.47 The light source device 1F shown is arranged in the same manner. Furthermore, the imaging element 51 is arranged separately from the light source groups 201 to 204. Even with such a configuration, the same effects as those of the fourth embodiment can be achieved.

[0321] Problems to be solved by the second embodiment and its modified example, the third embodiment and its modified example, and the fourth embodiment and its modified example described above and means for solving the problems will be described below.

[0322] [Issues to be solved]

[0323] For example, as disclosed in Patent Document 1 and Non-Patent Document 3, a three-dimensional shape measurement method using a stripe pattern is known. In this measurement method, light including a stripe pattern in which a plurality of bright lines are arranged is projected onto the object to be measured, and the image is taken while changing the phase of the stripe pattern, etc. Based on the multiple images obtained in this way, the three-dimensional shape is calculated by a prescribed calculation formula. For example, according to the phase shift method in which light including a stripe pattern in which a plurality of bright lines are periodically arranged is projected onto the object to be measured, and the image is taken while shifting the phase of the stripe pattern (i.e., the position of the bright lines in the arrangement direction), the three-dimensional shape can be measured with extremely high accuracy of several hundredths of the interval between the bright lines.

[0324] In such a measurement, it is considered that a plurality of stripe patterns with different phases or the like are outputted from a plurality of light sources, or a plurality of stripe elements used to form these stripe patterns. In this case, a plurality of light sources are arranged in a direction intersecting the optical axis. As such a light source, for example, an iPM laser is used. However, when a plurality of light sources are arranged in a direction intersecting the optical axis, the positions of the light sources in the same direction are necessarily offset from each other by the amount of the arrangement pitch of the light sources. If a positional offset occurs between a plurality of stripe patterns due to a positional offset between a plurality of light sources, the measurement error becomes larger.

[0325] The present embodiment is disclosed to provide a light source device, a light receiving and emitting module, and a three-dimensional shape measuring device capable of reducing a measurement error in three-dimensional shape measurement using a fringe pattern.

[0326] [Methods used to solve the problem]

[0327] [1] The light source device of this embodiment is a light source device for three-dimensional shape measurement.

[0328] The invention comprises a plurality of first light sources arranged in a direction intersecting with the optical axis direction so that the optical axis directions of the light sources are aligned with each other.

[0329] The plurality of first light sources project light including a first pattern onto a common projection area, wherein the first pattern is a pattern in which a plurality of bright lines are arranged along a first direction intersecting with an extending direction of the bright lines.

[0330] The plurality of first light sources are arranged along a second direction orthogonal to the first direction.

[0331] In the light source device of the above-mentioned [1], the plurality of first light sources are arranged along a second direction that is orthogonal to the first direction, which is the arrangement direction of the bright lines of the first pattern. In this case, even if the positions of the first light sources are offset from each other by the amount of the arrangement pitch, the direction of the offset is orthogonal to the arrangement direction of the bright lines of the first pattern. Therefore, even if the position of the first pattern is offset between the plurality of first light sources, the position offset does not affect the calculation of the three-dimensional shape. Therefore, according to the light source device of the above-mentioned [1], the measurement error in the three-dimensional shape measurement can be reduced.

[0332] [2] In the light source device of [1] above, the plurality of first light sources may project light including a first pattern onto a common projection area, the first pattern being a pattern in which a plurality of bright lines are arranged along a first direction intersecting an extension direction of the bright lines, and the intervals between the plurality of bright lines of the first pattern are equal among the plurality of first light sources. By projecting light including such a first pattern from the plurality of first light sources onto the common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0333] [3] The light source device of [1] or [2] may include a plurality of iPM lasers as a plurality of first light sources. In this case, the light source that outputs light including the first pattern can be miniaturized, and the light source device can be miniaturized.

[0334] [4] In the light source device of any one of [1] to [3] above, the plurality of iPM lasers may be formed as a monolithic chip. In this case, the plurality of iPM lasers can be formed in a single component, making it easier to assemble the light source device. In addition, compared with the case of combining and mounting individual components, positional deviation errors can be suppressed.

[0335] [5] In any of the light source devices of [1] to [4] above, the number of the plurality of first light sources may be n, and the shift amount of the bright lines between the plurality of first light sources may be 1 / n of the interval between the plurality of bright lines. In this case, three-dimensional shape measurement based on the phase shift method can be appropriately performed.

[0336] [6] Any one of the light source devices in [1] to [5] may further include a plurality of second light sources arranged in a direction intersecting the optical axis direction in a manner that their respective optical axis directions are consistent. The plurality of second light sources project light of a second pattern including a plurality of bright lines arranged along a third direction intersecting the direction in which the bright lines extend onto a common projection area. The plurality of second light sources are arranged along a fourth direction orthogonal to the third direction. In the light source device of [6], the plurality of second light sources are arranged along a fourth direction orthogonal to the third direction, which is the arrangement direction of the bright lines of the second pattern. In this case, even if the positions of the second light sources are offset from each other by an amount equal to the arrangement pitch, the direction of the offset is orthogonal to the arrangement direction of the bright lines of the second pattern. Therefore, even if a positional offset of the second pattern occurs between the plurality of second light sources, the positional offset does not affect the calculation of the three-dimensional shape. Therefore, according to the light source device of [6], the measurement error in three-dimensional shape measurement can be reduced.

[0337] [7] In the light source device of [6] above, the intervals between the plurality of bright lines of the second pattern may be equal among the plurality of second light sources. Alternatively, the positions of the plurality of bright lines in the third direction based on the optical axis of each second light source may be different among the plurality of second light sources. By projecting light including such a second pattern from the plurality of second light sources to a common projection area, three-dimensional shape measurement based on the phase shift method can be appropriately performed. That is, by performing three-dimensional shape measurement using the phase shift method at least twice using two light source groups, namely, a light source group consisting of a plurality of first light sources and a light source group consisting of a plurality of second light sources, the measurement accuracy can be improved.

[0338] [8] In the light source device of [6] above, the intervals between the plurality of bright lines of the second pattern may be different from the intervals between the plurality of bright lines of the first pattern. In this case, two stripe patterns having different intervals between bright lines can be used to perform three-dimensional shape measurement using a phase shift method, thereby further improving measurement accuracy.

[0339] [9] In any of the light source devices of [7] to [8] above, the third direction may intersect the first direction. In this case, three-dimensional shape measurement can be performed using two stripe patterns with bright lines arranged in different directions, thereby further improving measurement accuracy.

[0340]

[10] A light receiving and emitting module according to one embodiment of the present invention is a light receiving and emitting module for three-dimensional shape measurement, comprising: any one of the above-mentioned light source devices; and an imaging element that captures a first pattern projected onto a common projection area to generate image data. The light source device and the imaging element are disposed on a common substrate. According to the light receiving and emitting module, by including any one of the above-mentioned light source devices, the optical device can be miniaturized, and the measurement error in three-dimensional shape measurement can be reduced.

[0341]

[11] A three-dimensional shape measuring device according to one embodiment of the present invention includes: the image data generating device described above; and a data generating unit that generates three-dimensional shape data using the image data output from the image data generating device. According to the image data generating device, by including any of the light source devices described above, it is possible to reduce measurement errors in three-dimensional shape measurement.

[0342] Description of Reference Numerals

[0343] 1.1A…Semiconductor light emitting device

[0344] 1C~1F…Light source device

[0345] 1G, 1H, 1J…Light receiving and emitting modules

[0346] 2. 2A~2D…iPM laser

[0347] 2a…Side 1

[0348] 2b…Side 2

[0349] 3…Drive circuit

[0350] 6…Support base plate

[0351] 6a…Side 3

[0352] 6b…Side 4

[0353] 20…Semiconductor substrate

[0354] 21…1st cladding

[0355] 22…Active layer

[0356] 23…Second cladding

[0357] 25A, 25B…phase modulation layer

[0358] 25a…Basic Layer

[0359] 25b…Regions with different refractive indices

[0360] 26…Second electrode

[0361] 27…1st electrode

[0362] 31, 31A, 31B…Current source circuit

[0363] 32…Current mirror circuit

[0364] 33…Oscillation prevention circuit

[0365] 34…Switch action part

[0366] 34a…1st shift register

[0367] 34b…2nd shift register

[0368] 50…Camera Department

[0369] 51…Camera element

[0370] 201~204…Light source group

[0371] 311…Operational amplifier

[0372] 312…NMOS-FET

[0373] 314a to 314d ... the third switch

[0374] 316a~316d…partial circuit

[0375] 317…Digital-to-analog converter

[0376] 318…Serial-to-parallel converter

[0377] 322…Switch

[0378] 322a…1st switch

[0379] 322b…2nd switch

[0380] 323…1st current path

[0381] 324…Second current path

[0382] 331…NMOS-FET

[0383] 332…1PMOS-FET

[0384] 333…2nd PMOS-FET

[0385] D…Straight line

[0386] D1, D2, D11, D12, D21, D22, D31, D32, D41, D42…direction

[0387] G…Center of Gravity

[0388] I out ...drive current

[0389] L1…Light

[0390] O(x,y)…grid points

[0391] r(x,y)…distance

[0392] Rop…Resistor

[0393] Rop1~Rop4…Resistors

[0394] S4…Serial signal

[0395] S6…Parallel signal

[0396] Vop…Input voltage

[0397] WL1, WL2…bright line

[0398] φ(x,y)…angle.

Claims

1. A semiconductor light emitting device, characterized in that: include: A plurality of iPM lasers having a first surface and a second surface opposite to the first surface, and outputting light from the first surface; and a driving circuit for supplying a driving current for causing each of the plurality of iPM lasers to emit light, The driving circuit comprises: a current source circuit common to the plurality of iPM lasers; a plurality of switch units provided corresponding to the plurality of iPM lasers, respectively, for switching on / off the drive current; and A switch operating unit operates each of the plurality of switch units individually.

2. The semiconductor light emitting device according to claim 1, wherein: Each of the plurality of switch units includes a first switch and a second switch connected in series with the first switch. The switch action unit comprises: a first shift register for operating the first switch; and A second shift register operates the second switch.

3. The semiconductor light emitting device according to claim 1 or 2, characterized in that: The driving circuit further comprises a plurality of current mirror circuits corresponding to the plurality of iPM lasers respectively. Each of the plurality of current mirror circuits has a first current path and a second current path, and a current having a magnitude proportional to a magnitude of a current flowing through the first current path flows through the second current path. The first current path is connected to the common current source circuit, and the switch unit is provided on the first current path. The second current path is connected to the iPM laser corresponding to the current mirror circuit to which the second current path belongs, among the plurality of iPM lasers.

4. The semiconductor light emitting device according to any one of claims 1 to 3, characterized in that: The driving circuit further includes a plurality of oscillation prevention circuits corresponding to the plurality of iPM lasers, respectively. Each of the plurality of oscillation prevention circuits has: an NMOS-FET including a source terminal connected to the anode terminals of the respective iPM lasers and a drain terminal connected to the first constant potential line; a first PMOS-FET including a gate terminal connected to the source terminal of the NMOS-FET and a drain terminal connected to a second constant potential line having a lower potential than the first constant potential line; and a second PMOS-FET including a drain terminal connected to the source terminal of the first PMOS-FET, a source terminal connected to a third constant potential line having a potential higher than that of the second constant potential line, and a gate terminal, and supplying a current to the first PMOS-FET according to an input voltage to the gate terminal, The potential between the first PMOS-FET and the second PMOS-FET is supplied to the gate terminal of the NMOS-FET.

5. The semiconductor light emitting device according to any one of claims 1 to 4, characterized in that: The value of the current generated by the common current source circuit is variable.

6. The semiconductor light emitting device according to claim 5, characterized in that: The shared current source circuit also has: an operational amplifier for supplying an input voltage to one of a pair of input terminals; a transistor having a control terminal connected to an output terminal of the operational amplifier; and a resistor having one end connected to the current terminal of the transistor and the other input terminal of the operational amplifier and the other end connected to a fourth constant potential line, The resistance value of the resistor portion is variable, The switching operation of the plurality of switch units is synchronized with the operation of changing the resistance value of the resistor unit.

7. The semiconductor light emitting device according to claim 6, wherein: The resistor section includes a plurality of partial circuits connected in parallel to each other between the one end and the other end of the resistor section, Each of the plurality of partial circuits includes a resistor and a third switch connected in series between the one end and the other end of the resistor section, The switching operations of the plurality of switch units are synchronized with the switching operation of the third switch.

8. The semiconductor light emitting device according to claim 5, characterized in that: The shared current source circuit also has: an operational amplifier for supplying an input voltage to one of a pair of input terminals; a transistor having a control terminal connected to an output terminal of the operational amplifier; and a resistor, one end of which is connected to the current terminal of the transistor and the other input terminal of the operational amplifier, and the other end of which is connected to the fourth constant potential line, The switching operation of the plurality of switch units is synchronized with the operation of switching the value of the input voltage.

9. The semiconductor light emitting device according to claim 5, wherein: The driving circuit also has: a serial-to-parallel converter for converting a serial signal into a parallel signal, the serial signal including digital data indicating a current indication value for the shared current source circuit; and a digital-to-analog converter for converting the digital data converted into the parallel signals into an analog signal, The common current source circuit generates a current having a magnitude corresponding to the instruction value based on the analog signal.

10. The semiconductor light emitting device according to any one of claims 1 to 9, characterized in that: Each of the plurality of iPM lasers has: As an active layer of the light-emitting part; a phase modulation layer optically coupled to the active layer; a first cladding layer located on the first surface side of the active layer and the phase modulation layer; a second cladding layer located on the second surface side of the active layer and the phase modulation layer; a second electrode located on the second surface side of the second cladding layer; and a first electrode located on the first surface side of the first cladding layer, The phase modulation layer comprises: Basic layer; and A plurality of different refractive index regions having a refractive index different from that of the basic layer are provided in the basic layer in a manner distributed two-dimensionally on a surface perpendicular to the normal direction of the first surface, In a state where a virtual square grid is set on the surface, the plurality of regions with different refractive indexes are arranged in a state where the center of gravity of each of the plurality of regions with different refractive indexes is separated from the corresponding grid point by a predetermined distance, and the angle around each grid point in the virtual square grid, that is, the angle of the line segment connecting the center of gravity of each of the plurality of regions with different refractive indexes and the corresponding grid point relative to the virtual square grid, is set according to the phase distribution for forming the optical image, At least two of the angles in the plurality of different refractive index regions are different from each other.

11. The semiconductor light emitting device according to any one of claims 1 to 9, characterized in that: Each of the plurality of iPM lasers has: As an active layer of the light-emitting part; a phase modulation layer optically coupled to the active layer; a first cladding layer located on the first surface side of the active layer and the phase modulation layer; a second cladding layer located on the second surface side of the active layer and the phase modulation layer; a second electrode located on the second surface side of the second cladding layer; and a first electrode located on the first surface side of the first cladding layer, The phase modulation layer comprises: Basic layer; and A plurality of different refractive index regions having a refractive index different from that of the basic layer are provided in the basic layer in a manner distributed two-dimensionally on a surface perpendicular to the normal direction of the first surface, In a state where an imaginary square lattice is set on the surface, the plurality of regions with different refractive indexes are arranged in such a manner that the center of gravity of each of the plurality of regions with different refractive indexes is located on a straight line passing through a corresponding lattice point and inclined with respect to the imaginary square lattice, and the distance along the straight line between the center of gravity of each of the plurality of regions with different refractive indexes and the corresponding lattice point is set according to a phase distribution for forming an optical image, The slope of the straight line is uniform in the plurality of different refractive index regions.

12. The semiconductor light emitting device according to any one of claims 1 to 11, characterized in that: The plurality of iPM lasers are respectively formed as a single chip.

13. The semiconductor light emitting device according to claim 12, wherein: The plurality of iPM lasers and the driving circuit are disposed on a substrate common to each other.

14. The semiconductor light emitting device according to any one of claims 1 to 11, characterized in that: further comprising a supporting substrate, the supporting substrate comprising a third surface and a fourth surface opposite to the third surface, The plurality of iPM lasers are individually mounted on the third surface such that the second surface faces the third surface.

15. The semiconductor light emitting device according to claim 14, wherein: The driving circuit is provided on the third surface or the fourth surface of the supporting substrate.

16. The semiconductor light emitting device according to any one of claims 1 to 12, characterized in that: The driving circuit is connected to the plurality of iPM lasers through bump bonding.

Images