Laser irradiation device and system, object detection device, and distance measurement device

Abstract

Provided are a laser irradiation device and system, an object detection device, and a distance measurement device, which are capable of performing two-dimensional scanning on a laser beam with a simple mechanism and suppressing synchronization deviation. This laser irradiation device is provided with a laser light source and a two-dimensional deflector, and the two-dimensional deflector is provided with: a base body that is rotatable about a rotation axis; a first reflective surface disposed on the base along a circumference of a first radius; a second reflective surface disposed on the base along a circumference of a second radius; and a light guide section that guides the laser beam reflected by the first reflection surface to the second reflection surface, the first reflection surface being configured such that an inclination angle with respect to the rotation axis varies along a circumference of a first radius, the inclination angle of the first reflection surface being configured such that the laser beam recursively deflects in the first direction, and the second reflection surface being configured such that the inclination angle of the second reflection surface varies along a circumference of a second radius. The inclination angle with respect to the rotation axis varies along a circumference of a second radius, and the inclination angle of the second reflective surface is configured to recursively deflect the laser beam in the second direction.

Description

Technical Field

[0001] The present invention relates to a laser irradiation device and the like that performs two-dimensional scanning of a laser beam. Background Art

[0002] In recent years, laser scanning devices that perform two-dimensional scanning of laser beams have been used in various fields, including object detection, distance measurement systems, image display, and 3D scanners. To perform two-dimensional scanning of a laser beam, a horizontal scanning mechanism and a vertical scanning mechanism (or an X-scanning mechanism and a Y-scanning mechanism) are used to scan the laser beam.

[0003] Patent document 1 discloses a projection display device comprising: a laser light source; an acousto-optic modulator for modulating the laser light according to an image signal; a polygonal mirror for horizontally scanning the modulated laser light; and a galvanometer mirror for vertically scanning.

[0004] Patent Document 2 discloses a laser irradiation device that includes a movable plate that oscillates in the X direction and a movable plate that oscillates in the Y direction, matches the resonance frequencies of the two movable plates, and detects and compensates for the phase difference.

[0005] Patent Document 1: Japanese Patent Publication No. 2000-180759

[0006] Patent Document 2: Japanese Patent Publication No. 2004-20873

[0007] The projection display device described in Patent Document 1 includes an optical scanning unit that uses both a polygon mirror for horizontal scanning and a galvanometer mirror for vertical scanning. Separate drive devices are required for the polygon mirror and the galvanometer mirror, resulting in a large drive system. Furthermore, if the drive timings of the polygon mirror and the galvanometer mirror deviate (synchronize), accurate scanning cannot be performed.

[0008] In the laser irradiation device described in Patent Document 2, it is necessary to provide drive devices for the movable plate that swings in the X direction and the movable plate that swings in the Y direction, respectively, and complex control is required.

[0009] Meanwhile, for autonomous driving systems and driver assistance systems for mobile objects, such as automobiles, distance measurement and object recognition methods using Lidar (Light Detection and Ranging) are being researched. In these and other fields, there is a demand for compact laser irradiation devices that can perform two-dimensional scanning with a simple mechanism, minimize synchronization errors between X and Y scans, and achieve compactness. Summary of the Invention

[0010] One embodiment of the present invention is a laser irradiation device, characterized by comprising: a laser light source; a two-dimensional deflector for performing two-dimensional deflection scanning of a laser beam output by the laser light source in a first direction and a second direction, the two-dimensional deflector comprising: a base rotatable about a rotation axis; a first reflecting surface arranged on the base along a circumference of a first radius centered on the rotation axis; a second reflecting surface arranged on the base along a circumference of a second radius centered on the rotation axis; and a light guide for guiding the laser beam reflected by the first reflecting surface to the second reflecting surface, the first reflecting surface being configured such that an inclination angle relative to the rotation axis varies along the circumference of the first radius, the inclination angle of the first reflecting surface being configured such that, when the base is continuously rotated, the laser beam is recursively deflected in the first direction, the second reflecting surface being configured such that an inclination angle relative to the rotation axis varies along the circumference of the second radius, the inclination angle of the second reflecting surface being configured such that, when the base is continuously rotated, the laser beam is recursively deflected in the second direction.

[0011] According to the present invention, a compact laser irradiation device can be provided that can two-dimensionally scan a laser beam with a simple mechanism, suppress synchronization deviation between X scanning and Y scanning, and can be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 (a) is a typical perspective view showing a schematic structure of a scanning optical system of the laser irradiation device according to the first embodiment; Figure 1 (b) is a top view of the two-dimensional deflector.

[0013] Figure 2 It is a three-dimensional diagram of a two-dimensional deflector.

[0014] Figure 3 (a) is a cross-sectional view of the laser irradiation device according to the first embodiment taken along a radius R1; Figure 3 (b) is a cross-sectional view of the laser irradiation device according to the first embodiment taken along the radius R2.

[0015] Figure 4 (a) is a diagram showing the inclination of the reflecting surface 213 and the reflection direction of the laser beam in one subarea (angle coordinate 0° to 45°); Figure 4 (b) is a typical diagram showing that the inclination of the reflecting surface 213 is repeated in the same manner in each section (i=1 to 8).

[0016] Figure 5 (a) is a typical diagram showing the relationship between the inclination of the reflecting surface 214 and the reflection direction of the laser beam in the angular coordinate range of 0° to 360°; Figure 5(b) is a typical diagram showing a continuous linear change in the tilt of the reflecting surface 214 .

[0017] Figure 6 (a) is a typical diagram of a light guide portion 300a in which reflectors 301 to 304 are provided respectively; Figure 6 (b) is a typical diagram of the light guide portion 300b which is a prism having an internal total reflection surface and is an integral body.

[0018] Figure 7 (a) is a diagram showing the range of the laser beam deflected and scanned by the reflective surface 213; Figure 7 (b) is a diagram showing the range scanned by the laser beam deflected by the reflection surface 214 .

[0019] Figure 8 This is a perspective view of a two-dimensional deflector included in the irradiation device according to the second embodiment.

[0020] Figure 9 (a) is a typical diagram showing the relationship between the inclination of the reflecting surface 214a and the reflection direction of the laser beam in the angular coordinate range of 0° to 360°; Figure 9 (b) is a typical diagram showing that the inclination of the reflecting surface 214a changes in stages.

[0021] Figure 10 (a) is a cross-sectional view of the laser irradiation device according to Embodiment 3 cut along radius R1; Figure 10 (b) is a typical diagram showing how the irradiation position on the reflecting surface 214 changes.

[0022] Figure 11 (a) is a diagram showing an example in which a front lens 103 of a conjugate relay lens is arranged between the irradiation position P1 and the reflecting mirror 301 in Embodiment 3; Figure 11 (b) is a diagram showing an example in which the rear lens 104 of the conjugate relay lens is arranged between the reflecting mirror 304 and the irradiation position P2 in the third embodiment.

[0023] Figure 12 This is a typical diagram showing a portion of the laser irradiation system involved in embodiment 4.

[0024] Figure 13 (a) is a diagram showing a free-form surface reflecting mirror 301A as a reflecting mirror located closest to the reflecting surface 213 in the fifth embodiment; Figure 13 (b) is a diagram showing a free-form surface reflecting mirror 304A arranged as a reflecting mirror located closest to the reflecting surface 214 in the fifth embodiment.

[0025] Figure 14(a) is a diagram showing the shape of the free-form surface reflector used in Embodiment 5; Figure 14 (b) is a diagram showing the twist of the surface of the free-form surface mirror used in the fifth embodiment.

[0026] Figure 15 (a) is a diagram showing an example in which the irradiation spot is deformed from a perfect circle; Figure 15 (b) is a diagram showing an example in which the shape of the irradiation spot is improved in the fifth embodiment.

[0027] Figure 16 (a) is a diagram showing that in embodiment 6, a laser beam is guided from irradiation position P1 to irradiation position P2 using three reflecting surfaces; Figure 16 (b) is a diagram showing that in the sixth embodiment, a laser beam is guided from the irradiation position P1 to the irradiation position P2 by three reflecting surfaces.

[0028] Figure 17 This is a block diagram for explaining the basic structure of the object detection device involved in the seventh embodiment.

[0029] Description of Reference Numerals

[0030] 100...Laser irradiation device

[0031] 101...Laser light source

[0032] 103...Front lens

[0033] 104... rear lens

[0034] 105...projection lens

[0035] 211, 211A... Two-dimensional deflector

[0036] 212...motor

[0037] 213...reflective surface

[0038] 214, 214a...reflecting surface

[0039] 300a, 300b...light guide

[0040] 301-304...Reflector

[0041] 301A, 304A...Free-form surface mirrors

[0042] 301B~303B……Reflector

[0043] 500...Controller

[0044] 501... Light source control unit

[0045] 502...Motor drive unit

[0046] 503...Light sensor unit

[0047] 504...Data Processing Department

[0048] 505……I / O Department

[0049] IM1...First Interview

[0050] IM2...Secondary Surface

[0051] P1, P2... irradiation position

[0052] R1, R2...radius DETAILED DESCRIPTION

[0053] The following describes a laser irradiation device and other embodiments of the present invention with reference to the accompanying drawings. The embodiments described below are merely illustrative; for example, those skilled in the art may appropriately modify the technical details without departing from the spirit of the present invention. In the drawings used in the following descriptions of the embodiments and examples, elements designated by the same reference numerals have the same functions unless otherwise specified. In the drawings, where multiple identical elements are present, the reference numerals and their descriptions may be omitted.

[0054] In addition, for the sake of convenience in illustration and explanation, the drawings may sometimes be representative, and therefore the shapes, sizes, and arrangements of the units depicted in the drawings may not necessarily correspond exactly to the actual objects. For example, even if a single lens is depicted in a drawing, it may be composed of multiple lenses unless otherwise specified.

[0055] [Implementation Method 1]

[0056] Figure 1 (a) is a typical perspective view showing a schematic configuration of a scanning optical system of the laser irradiation device 100 according to Embodiment 1. For ease of explanation, the figure omits the mechanical structure for installing optical components, a body, electrical wiring, and the like.

[0057] The laser irradiation device 100 can two-dimensionally scan and output the laser beam output from the laser light source 101, as in so-called raster scanning. Figure 1(a) shows a hypothetical irradiated surface IRP. After the laser beam is deflected along the X direction from its starting point to its end point on scan line SC1, it is then deflected along the X direction from its starting point to its end point on scan line SC2, which is located at a different position in the Z direction. Similarly, the laser beam can be deflected along the X direction from its starting point to its end point in the order of scan line SC3, scan line SC4, ..., scan line SC8, before returning to scan line SC1, recursively repeating the same scanning procedure. In other words, a single frame of irradiation consisting of scan lines SC1 through SC8 can be repeatedly performed.

[0058] For ease of explanation and illustration, eight scanning lines, SC1 through SC8, are shown. However, the number of scanning lines constituting one frame of irradiation and the scanning angles in the X and Y directions can be appropriately set depending on the application of the laser irradiation device 100, such as object detection, ranging systems, image display, and 3D scanners. Furthermore, the direction of the scanning lines SC is not necessarily horizontal (parallel to the X direction) and can be changed depending on the application. For example, in the case of LiDAR (Light Detection and Ranging) applications, the laser irradiation device 100 can be configured so that the scanning lines SC are oriented vertically (parallel to the Z direction).

[0059] For convenience of explanation, an XZ plane defined by the X-axis and the Z-axis is exemplified as the virtual irradiated surface IRP, but the object, position, and direction irradiated by the deflected and scanned laser beam are not limited to the illustrated example.

[0060] [Overall structure]

[0061] like Figure 1 As shown in FIG. 1 ( a ), the laser irradiation device 100 includes a laser light source 101 , a two-dimensional deflector 211 , and reflecting mirrors 301 to 304 .

[0062] Laser light source 101 uses a light-emitting device with a wavelength and output intensity appropriate for the application. For example, in LiDAR applications, a laser diode emitting light in the infrared or other invisible region is preferably used, but the present invention is not limited to this. Laser light source 101 may also include a collimating lens (not shown). Depending on the application of laser irradiation device 100, laser light source 101 can be configured to emit light continuously or in pulsed mode.

[0063] The two-dimensional deflector 211 is a disc-shaped component that can rotate about the rotation axis MX. The laser beam output by the laser light source 101 is irradiated onto the reflection surface 213 (first reflection surface) of the two-dimensional deflector 211 at irradiation position P1 (first irradiation position). The laser beam DFX reflected by the reflection surface 213 is sequentially reflected by the reflection mirrors 301, 302, 303, and 304, and irradiates the reflection surface 214 (second reflection surface) at irradiation position P2 (second irradiation position). The laser beam DFXY reflected by the reflection surface 214 is output from the laser irradiation device 100 as a two-dimensionally deflected output beam.

[0064] The line connecting the irradiation position P1 of the laser beam irradiating the reflecting surface 213 and the rotation axis MX as the rotation center of the two-dimensional deflector 211 is set as the radius R1, and the radius orthogonal to the radius R1 (the line orthogonal to the radius R1 through the rotation axis MX) is set as the radius R2. As described later, the irradiation position P2 of the laser beam deflected and scanned by the reflecting surface 213 irradiating the reflecting surface 214 moves back and forth slightly in the X direction with the position where the radius R2 intersects the reflecting surface 214 as the center. The radius R2 located at the center of the reciprocating movement is orthogonal to the radius R1, but since the line connecting the irradiation position P2 and the rotation axis MX moves slightly over time, it cannot be strictly said that it is always orthogonal to the radius R1. However, it can be said that the line connecting the irradiation position P2 and the rotation axis MX is approximately orthogonal to the radius R1. In this regard, in embodiment 3, reference is made to Figure 10 (b) will be explained further.

[0065] exist Figure 1 (b) shows a top view of the two-dimensional deflector 211. Figure 2 A perspective view of the two-dimensional deflector 211 is shown in FIG. Figure 3 (a) shows a cross-sectional view of the laser irradiation device 100 cut along the radius R1. Figure 3 (b) shows a cross-sectional view of the laser irradiation device 100 cut along the radius R2. Figure 3 (a) Figure 3 As shown in (b), the laser irradiation device 100 includes a rotatable disk-shaped two-dimensional deflector 211 and a motor 212 that rotates the two-dimensional deflector 211 about a rotation axis MX. Strip-shaped reflective surfaces, namely, reflective surfaces 213 and 214, are provided on the main surface of the disk-shaped two-dimensional deflector 211 along the circumference.

[0066] The manufacturing method of the two-dimensional deflector 211 will be described in detail. A disc-shaped base body having a strip-shaped reflective surface 213 and a reflective surface 214 arranged along its circumference can be manufactured at low cost by, for example, processing a metal base material using a stamping and extrusion process. Alternatively, the disc-shaped base body can be manufactured by cutting or grinding the metal base material. Alternatively, the base body can be manufactured by molding glass or resin as a molding material, and a metal film can be formed on the portion that will become the reflective surface by vapor deposition or plating.

[0067] The two-dimensional deflector 211 performs a deflection scan of one frame by rotating one circle around the rotation axis MX. Figure 2 As shown, the angular coordinates are set by rotating counterclockwise around the rotation axis MX (0°, 90°, 180°, and 270° are shown in the figure).

[0068] (About X-direction scanning)

[0069] The reflective surface 213 is used to reflect the irradiated surface IRP ( Figure 1 (a)) is a reflecting surface that deflects and scans the laser beam in the X direction. The strip-shaped reflecting surface 213 is twisted in such a way that the angle relative to the rotation axis MX changes according to the position on the angular coordinate. In one frame, taking the case of scanning 8 times in the X direction along the scanning lines SC1 to SC8 as an example, the reflecting surface 213 is equally divided into 8 partitions (in order to distinguish the partitions, if referred to by the reference numeral i, i=1 to 8). Each partition has a width of 45° in the angular coordinate centered on the rotation axis MX. In other words, if deflection scanning is performed in the X direction along M scanning lines (M is an integer greater than 2), the reflecting surface 213 is constructed to have partitions formed by dividing the circumference into M equal parts (M is an integer greater than 2), and the inclination angle of the reflecting surface changes similarly in each partition.

[0070] exist Figure 4 (a) shows the inclination of the reflecting surface 213 and the reflection direction of the laser beam in one partition (angle coordinate 0° to 45°). In addition, the axis BX shown in the figure is an axis parallel to the rotation axis MX and passes through the reflecting surface 213. Figure 4 (b) typically shows a structure in which the inclination of the reflecting surface 213 is repeated in the same manner in each section (i=1 to 8).

[0071] exist Figure 4 (a) and Figure 4 In (b), the position of the reflecting surface is shown by Figure 2 The position is defined by the angular coordinates described in . In addition, the inclination angle of the reflecting surface is the inclination angle of the reflecting surface when the main surface of the disk-shaped two-dimensional deflector 211 (that is, the surface perpendicular to the axis BX) is used as a reference.

[0072] like Figure 4 As shown in (b), in each partition of the reflecting surface 213, the reflecting surface is configured in such a way that the inclination angle of the reflecting surface changes linearly with respect to the position. Since each partition is adjacently arranged, Figure 4 As shown in (b), the inclination angle of the reflecting surface becomes discontinuous at the boundary between the partitions, that is, at the location where the coordinates are multiples of 45°.

[0073] When the two-dimensional deflector 211 is rotated along the Figure 1 When the laser beam is rotated in the R direction shown in (a), the angular coordinates of the portion irradiated with the laser beam at the irradiation position P1 continuously change in the order of 0°→90°→180°→360°(=0°)→90°.

[0074] like Figure 4 As shown in (a), even if the reflecting surface 213 rotates around the rotation axis MX and the portion irradiated by the laser beam changes, the incident light beam always enters the reflecting surface 213 at an angle β relative to the axis BX. On the other hand, within each partition, the inclination angle of the reflecting surface varies within the range of -α to +α depending on the position of the reflecting surface. Therefore, as Figure 4 As shown in (a) of FIG. , the direction of the laser beam reflected by the reflecting surface 213 varies within an angular range of 4α, from (β - 2×α) to (β + 2×α), relative to the axis BX. In other words, when the optical surface (reflecting surface) is continuously rotated at a constant speed, the tilt angle is configured so that the laser beam is recursively deflected in a constant direction at a constant deflection speed.

[0075] exist Figure 7 (a) shows the range of the laser beam deflected and scanned by the reflective surface 213. Figure 1 (a) of the laser beam is continuously rotated in the R direction, and the laser beam reflected by the reflecting surface 213 is Figure 7 In (a), RD1 is continuously deflected (scanned) toward RD2, and upon reaching RD2, it instantly returns to RD1 and deflects (scans) toward RD2 again. Since deflection scanning is performed from RD1 to RD2 in each of the eight sections, when the two-dimensional deflector 211 rotates one circle, eight deflection scans are performed from RD1 to RD2. In other words, Figure 4 As shown in (a), each partition of the reflecting surface 213 can deflect and scan the outgoing light beam within the angle range of RD1 (relative to the axis BX (β-2×α)) to RD2 (relative to the axis BX (β+2×α)).

[0076] In addition, if the reflecting surface 213 is rotated in the opposite direction to the R direction, the outgoing light beam will be Figure 7In (a), RD2 continuously deflects (scans) toward RD1, and upon reaching RD1, instantly returns to RD2, and deflects (scans) toward RD1 again.

[0077] Thus, the two-dimensional deflector 211 can be used to continuously rotate the rotating body at a constant speed, thereby achieving a simple driving method. Figure 1 In (a)), the laser beam is recursively deflected and scanned at an equal speed in the X direction.

[0078] (Light guiding portion from the reflecting surface 213 to the reflecting surface 214)

[0079] like Figure 1 As shown in (a), at irradiation position P1, laser beam DFX reflected (deflected and scanned) by reflection surface 213 is sequentially reflected by reflection mirrors 301, 302, 303, and 304, and irradiates reflection surface 214 at irradiation position P2. In other words, reflection mirrors 301 to 304 constitute a light guide for guiding the laser beam reflected by reflection surface 213 to reflection surface 214.

[0080] The laser beam DFX guided to the irradiation position P2 via the reflecting mirrors 301 to 304 is periodically deflected and scanned in the X direction by the reflecting surface 213. Figure 1 In (a), to facilitate understanding of the trajectory of the laser beam, arrows are used to indicate the movement direction of the laser beam DFX associated with deflection scanning in each of the mirrors 301 to 304 arranged as a cross-mirror configuration. Furthermore, because the relative positions of the laser light source 101 and the two-dimensional deflector 211 are fixed, the irradiation position P1 remains fixed at radius R1. Meanwhile, the irradiation position P2 irradiating the reflecting surface 214 periodically moves slightly in the X direction, centered around radius R2, which is perpendicular to radius R1.

[0081] As a method of forming the light guide portion, Figure 6 As typically shown in (a), reflecting mirrors 301 to 304 may be provided to form a light guide 300 a that guides the laser beam from the reflecting surface 213 to the reflecting surface 214 .

[0082] Or, as Figure 6 As typically shown in (b), a prism having four internal total reflection surfaces may be formed as a single body from an optical material such as glass to form a light guide portion 300 b that guides the laser beam from the reflection surface 213 to the reflection surface 214 .

[0083] (About Z-direction scanning)

[0084] The reflecting surface 214 is used to reflect the light on the imaginary illuminated surface IRP ( Figure 1The reflective surface 214 deflects and scans the laser beam in the Z direction in (a). The strip-shaped reflective surface 214 is twisted so that its angle relative to the rotation axis MX changes depending on its position on the angular coordinate. For example, when the laser beam is scanned once in the Z direction in one frame, the tilt of the reflective surface 214 is configured to continuously change (e.g., increase monotonically) between angular coordinates of 0° and 360° (one rotation).

[0085] Figure 5 (a) is a typical diagram showing the relationship between the inclination of the reflecting surface 214 and the reflection direction of the laser beam in the angular coordinates 0° to 360°. In addition, the axis AX shown in the figure is an axis parallel to the rotation axis MX and passing through the reflecting surface 214. In addition, Figure 5 (b) is a typical diagram of an example reflecting surface 214 where the tilt thereof continuously changes linearly.

[0086] exist Figure 5 (a) and Figure 5 In (b), the position of the reflecting surface is shown by Figure 2 The position specified by the angular coordinates described in . In addition, the inclination angle of the reflecting surface is shown as the inclination angle of the reflecting surface when the main surface of the circular plate-shaped two-dimensional deflector 211 (that is, the surface perpendicular to the axis AX) is used as a reference. Figure 2 、 Figure 5 As shown in (b), the inclination angle of the reflecting surface becomes discontinuous at a position where the angular coordinate is 0° (=360°).

[0087] When the two-dimensional deflector 211 is rotated along the Figure 1 When the lens rotates in the R direction of (a), the angular coordinates of the portion irradiated with the laser beam at the irradiation position P2 continuously change in the manner of 0°→90°→180°→360°(=0°)→90° . . .

[0088] Even if the reflecting surface 214 rotates around the rotation axis MX and the portion irradiated by the laser beam changes, Figure 5 As shown in (a), the incident light beam always enters the reflecting surface 214 at an angle of γ relative to the axis AX.

[0089] On the other hand, the inclination angle of the reflecting surface 214 varies in the range of -δ to +δ according to the position of the reflecting surface. Figure 5 As shown in (a) of FIG. 1 , the direction of the laser beam reflected by the reflecting surface 214 varies within an angular range of 4δ, from (γ-2×δ) to (γ+2×δ), relative to the axis AX. In other words, when the optical surface (reflecting surface) is continuously rotated at a constant speed, the tilt angle is configured so that the laser beam is recursively deflected in a constant direction at a constant deflection speed.

[0090] exist Figure 7(b) shows the range of the laser beam deflected and scanned by the reflective surface 214. Figure 1 When the R direction shown in (a) is continuously rotated, the laser beam (outgoing beam) reflected by the reflecting surface 214 is Figure 7 (b) RD3 is continuously deflected (scanned) toward RD4, and when it reaches RD4, it instantly returns to RD3 and deflects (scans) toward RD4 again. When the two-dimensional deflector 211 rotates one circle, a deflection scan is performed from RD3 toward RD4. In other words, Figure 7 As shown in (b), the reflecting surface 214 can deflect and scan the outgoing light beam within the angle range from RD3 (relative to the axis AX (γ-2×δ)) to RD4 (relative to the axis AX (γ+2×δ)).

[0091] In addition, if the reflecting surface 214 is rotated in the opposite direction to the R direction, the outgoing light beam will be Figure 7 In (b), RD4 continuously deflects (scans) toward RD3, and upon reaching RD3, instantly returns to RD4, and deflects (scans) toward RD3 again.

[0092] Thus, the two-dimensional deflector 211 can be used to continuously rotate the rotating body at a constant speed, thereby achieving a simple driving method. Figure 1 In (a)), the laser beam is recursively deflected and scanned in the Z direction at an equal speed.

[0093] Since the laser beam (outgoing beam) reflected by the reflecting surface 214 includes the deflection scan caused by the reflecting surface 213 and the deflection scan caused by the reflecting surface 214, Figure 1 As shown in (a), the irradiated surface IRP is subjected to two-dimensional deflection scanning.

[0094] As described above, according to this embodiment, a laser beam can be two-dimensionally scanned and irradiated using a simple mechanism. Since the reflective surface 213 for X scanning and the reflective surface 214 for Y scanning (Z scanning in the irradiated surface IRP) are fixed on a rotatable circular two-dimensional deflector 211, the relative positional relationship does not change. Therefore, unlike the case of using two galvanometer scanners, it is easy to prevent synchronization deviation between the X scanning and the Y scanning. Moreover, compared with the case of using two galvanometer scanners, the laser irradiation device can be compactly constructed. The laser irradiation device involved in this embodiment can be used in a wide range of fields such as automatic driving systems for mobile bodies represented by automobiles, laser radars (Lidar, Light Detection and Ranging) for driving assistance systems, ranging systems, object recognition systems, and monitoring systems.

[0095] [Implementation Method 2]

[0096] The laser irradiation device according to Embodiment 2 will be described. The illustrations and descriptions of matters common to Embodiment 1 will be simplified or omitted. This embodiment shares the same characteristics as Embodiment 1 in that the reflective surface for X scanning and the reflective surface for Y scanning (Z scanning of the irradiated surface IRP) are fixed to a rotatable, circular, two-dimensional deflector. However, the structure of the reflective surface for Y scanning in this embodiment differs from that in Embodiment 1.

[0097] Figure 8 A perspective view showing a two-dimensional deflector 211A included in the irradiation device according to this embodiment. Figure 8 Reference to the description of Implementation 1 Figure 2 Corresponding drawings. Similar to the two-dimensional deflector 211 of embodiment 1, the two-dimensional deflector 211A involved in this embodiment also rotates once around the rotation axis MX for each frame scan. Here, in order to specify the position within the reflection surface, as shown in FIG. Figure 8 As shown, the angular coordinates are set by rotating counterclockwise around the rotation axis MX (0°, 90°, 180°, and 270° are shown in the figure).

[0098] (About X-direction scanning)

[0099] The reflective surface 213 is used to reflect the irradiated surface IRP ( Figure 1 (a)) makes the laser beam deflect in the X direction and scan the reflective surface. Figure 4 (a) Figure 4 Since the two-dimensional deflector 211 of the first embodiment described in (b) and the like is the same, the description thereof is omitted.

[0100] (Light guiding portion from the reflecting surface 213 to the reflecting surface 214a)

[0101] Since it is the same as the first embodiment, the description is omitted.

[0102] (About Z-direction scanning)

[0103] The reflecting surface 214a is used to reflect the light on the imaginary illuminated surface IRP ( Figure 1 The reflective surface 214a deflects and scans the laser beam in the Z direction in (a). The strip-shaped reflective surface 214a is twisted so that its angle relative to the rotation axis MX changes in stages (steps) depending on its position on the angular coordinates. For example, when the laser beam is scanned once in the Z direction in one frame, the tilt of the reflective surface 214a is configured to change in stages (steps) between 0° and 360° (one rotation).

[0104] In embodiment 1, as referenced Figure 5As described in (b) of FIG. 2 , the inclination of the reflecting surface 214 is configured to continuously change between the angular coordinates 0° to 360° (one rotation). Therefore, while the two-dimensional deflector 211 is rotated and the X-direction scanning is performed along each scanning line (scanning line SC1 to scanning line SC8) corresponding to each partition of the reflecting surface 213, the inclination angle of the reflecting surface 214 continuously changes. Figure 1 In the irradiated surface IRP shown in (a) of FIG. 8 , each scanning line (scanning line SC1 to scanning line SC8 ) is not completely parallel to the X direction (horizontal direction).

[0105] In this embodiment, the trajectory of the laser beam does not move in the Z direction on the irradiated surface IRP during scanning of one scanning line. That is, each scanning line (scanning line SC1 to scanning line SC8) is parallel to the X direction (horizontal direction).

[0106] Figure 9 (a) is a typical diagram showing the relationship between the inclination of the reflecting surface 214a and the reflection direction of the laser beam in the angular coordinates 0° to 360°. In addition, the axis AX shown in the figure is an axis parallel to the rotation axis MX and passing through the reflecting surface 214a. In addition, Figure 9 (b) is a typical diagram showing that the inclination of the reflecting surface 214a changes in stages (steps).

[0107] exist Figure 9 (a) and Figure 9 In (b), the position of the reflecting surface is shown by Figure 8 The position is defined by the angular coordinates described in . In addition, the inclination angle of the reflecting surface is shown as the inclination angle of the reflecting surface when the main surface of the disk-shaped two-dimensional deflector 211A (that is, the surface perpendicular to the axis AX) is used as a reference.

[0108] In this embodiment, the reflecting surface 214a is equally divided into the same number of partitions (e.g., i=8) as the reflecting surface 213. The reflecting surface 213 and the reflecting surface 214a are divided into the same angular coordinates. Figure 8 、 Figure 9 As shown in (b), the inclination angle of the reflecting surface becomes discontinuous at the divided boundary.

[0109] When the two-dimensional deflector 211A is rotated along the Figure 1 When the lens rotates in the R direction of (a), the angular coordinates of the portion irradiated with the laser beam at the irradiation position P2 continuously change in the manner of 0°→90°→180°→360°(=0°)→90° . . .

[0110] Even if the reflecting surface 214a rotates around the rotation axis MX and the portion irradiated by the laser beam changes, Figure 9As shown in (a), the incident light beam always enters the reflecting surface 214a at an angle of γ relative to the axis AX.

[0111] On the other hand, the inclination angle of the reflecting surface 214a changes in stages within the range of -δ to +δ according to the position of the reflecting surface. Figure 9 As shown in (a), the direction of the laser beam reflected by the reflecting surface 214a varies within an angular range of 4δ, from (γ - 2 × δ) to (γ + 2 × δ), relative to the axis AX. Specifically, when the optical surface (reflecting surface) is continuously rotated at a constant speed, the tilt angle is configured such that the laser beam is deflected in a constant direction in a stepwise and recursive manner, as the sections i = 1 to 8 are switched.

[0112] Regarding the range of laser beam deflection, Figure 7 The same as the embodiment 1 described in (b). Figure 1 When the R direction shown in (a) is continuously rotated, the outgoing light beam is Figure 7 (b) RD3 is deflected (scanned) stepwise toward RD4, and upon reaching RD4, it instantly returns to RD3 and deflects (scans) toward RD4 again. When the two-dimensional deflector 211A rotates one circle, a deflection scan is performed from RD3 toward RD4. In other words, Figure 7 As shown in (b), the reflecting surface 214a can deflect and scan the outgoing light beam within the angle range from RD3 (relative to the axis AX (γ-2×δ)) to RD4 (relative to the axis AX (γ+2×δ)).

[0113] In addition, if the reflecting surface 214a is rotated in the opposite direction to the R direction, the outgoing light beam will be Figure 7 In (b), RD4 deflects (sweeps) toward RD3 in stages, and upon reaching RD3, instantly returns to RD4 and deflects (sweeps) toward RD3 again.

[0114] Thus, the two-dimensional deflector 211A can be used to continuously rotate the rotating body at a constant speed, thereby achieving a simple driving method. Figure 1 In (a)), the laser beam is deflected and scanned in the Z direction in a step-by-step and recursive manner.

[0115] As described above, according to this embodiment, a laser beam can be two-dimensionally scanned and irradiated using a simple mechanism. Since the reflective surface 213 for X scanning and the reflective surface 214a for Y scanning (Z scanning in the irradiated surface IRP) are fixed on a rotatable circular two-dimensional deflector 211A, the relative positional relationship does not change. Therefore, unlike the case of using two galvanometer scanners, it is easy to prevent synchronization deviation between the X scanning and the Y scanning. Moreover, compared with the case of using two galvanometer scanners, the laser irradiation device can be compactly constructed. Furthermore, compared with embodiment 1, the horizontality (parallelism with respect to the X axis) of each scanning line can be improved. The laser irradiation device of this embodiment can be used in a wide range of fields such as automatic driving systems for mobile bodies represented by automobiles, laser radars (Lidar, Light Detection and Ranging) for driving assistance systems, ranging systems, object recognition systems, and monitoring systems.

[0116] [Implementation Method 3]

[0117] The laser irradiation device according to Embodiment 3 will be described. Illustrations and descriptions of matters common to Embodiment 1 or 2 will be simplified or omitted. This embodiment shares with Embodiments 1 and 2 that the reflective surface for X scanning and the reflective surface for Y scanning are fixed to a rotatable, circular, two-dimensional deflector.

[0118] In the first and second embodiments, as shown in FIG. Figure 7 As described in (a), the laser beam is deflected and scanned by the reflecting surface 213 within the angle range from RD1 (relative to the axis BX) (β-2×α)) to RD2 (relative to the axis BX (β+2×α)). Figure 10 (a) shows the Figure 1 (a) is a partial cross-sectional view of the radius R1. Figure 10 (b) typically shows a case where the irradiation position changes on the reflection surface 214.

[0119] As the laser beam is deflected and scanned between RD1 and RD2 by the reflective surface 213, the irradiation position P2 changes. Figure 10 As shown in (b), when the laser beam is located at the center of RD1 and RD2, irradiation position P2 is located on radius R2. Otherwise, irradiation position P2 is located slightly off radius R2. In other words, the line connecting irradiation position P1 and rotation axis MX and the line connecting irradiation position P2 and rotation axis MX are not always strictly orthogonal, but are approximately orthogonal.

[0120] In the first embodiment, the inclination angle of the reflecting surface 214 becomes discontinuous at the angular coordinate 0°, which is the starting point of one frame (= the angular coordinate 360°, which is the end point of one frame). In the second embodiment, the inclination angle of the reflecting surface 214a becomes discontinuous at the angular coordinate corresponding to the starting point (= the end point) of each scanning line, that is, the angular coordinate of the boundary between the partitions. Figure 10 In (b), when the laser beam takes the trajectory of RD1 or RD2 at the start or end point of each scan line, the position where the inclination angle of the reflecting surface 214 becomes discontinuous is immediately before or immediately after the position where the inclination angle becomes discontinuous. Therefore, before or after the point where the laser should be irradiated at the boundary where the inclination angle becomes discontinuous, the laser may be irradiated at a position that is off-center, causing irregular scanning.

[0121] Therefore, in this embodiment, a conjugate relay lens is provided so that the irradiation position P1 and the irradiation position P2 are in a conjugate relationship. Figure 11 As shown in (a), the front lens 103 of the conjugate relay lens is arranged between the irradiation position P1 and the reflector 301. Figure 11 As shown in (b), the rear lens 104 of the conjugate relay lens is arranged between the reflector 304 and the irradiation position P2. When the conjugate relay lens is provided so that the irradiation position P1 and the irradiation position P2 are in a conjugate relationship, even if the reflection surface 213 (irradiation position P1) is deflected, the movement of the irradiation position P2 on the reflection surface 214 can be suppressed. Therefore, on the imaginary irradiated surface IRP ( Figure 1 In (a)), the problem of scanning becoming irregular can be suppressed.

[0122] [Implementation Method 4]

[0123] The laser irradiation system according to Embodiment 4 will be described. Illustrations and descriptions of matters common to the previously described embodiments will be simplified or omitted. This embodiment shares the same characteristics as the previously described embodiments in that the reflective surface for X scanning and the reflective surface for Y scanning are fixed to a rotatable, circular, two-dimensional deflector.

[0124] This embodiment is a laser irradiation system in which a projection lens is further provided in the laser irradiation device according to any of the above embodiments. Figure 12 This is a typical diagram showing a portion of a laser irradiation system. In this embodiment, projection lens 105 is used to project the laser beam scanned by the laser irradiation device onto the primary surface IM1 and the secondary surface IM2. By making the focal length of projection lens 105 variable, the field of view angle ω can be arbitrarily set according to the distance L when the secondary surface IM2 is used as the target surface.

[0125] [Implementation 5]

[0126] The laser irradiation device according to Embodiment 5 will be described. Illustrations and descriptions of matters common to the previously described embodiments will be simplified or omitted. This embodiment shares the same characteristics as the previously described embodiments in that the reflective surface for X scanning and the reflective surface for Y scanning are fixed to a rotatable, circular, two-dimensional deflector.

[0127] In this embodiment, Figure 6 As a part of the reflector of the light guide portion 300a shown in (a), a reflector having a reflective surface with a free-form shape to which a twist is continuously applied (free-form reflective mirror) is used instead of a reflective mirror with a flat reflective surface.

[0128] Specifically, if Figure 13 As shown in (a), as a reflector located closest to the reflective surface 213, a free-form surface reflector 301A is configured. Figure 13 As shown in (b), a free-form surface reflector 304A is configured as a reflector located closest to the reflective surface 214. Figure 14 (a) Figure 14 As shown in (b), free-form surface mirror 301A includes a reflective surface formed by continuously imparting a distortion amount η on a completely flat surface in the y-coordinate. Using free-form surface mirrors, even when spot rotation occurs due to the distorted surfaces on reflective surfaces 213 and 214, allows adjustment of the laser beam spot shape. Furthermore, the distortion adjustment amount of free-form surface mirrors 301A and 304A does not necessarily have to be linear.

[0129] On the irradiated surface IRP( Figure 1 The spot shape of the laser beam in (a) is as follows: Figure 15 In the case where the shape is deformed from a perfect circle as shown in (a), according to this embodiment, as Figure 15 As shown in (b), the roundness of the spot shape can be improved. In addition, any reflector between the irradiation position P1 and the irradiation position P2 can be set as a free-form surface reflector. The free-form surface reflector can be made of Figure 6 The internal total reflection surface of the prism shown in (b) is constructed.

[0130] [Implementation Method 6]

[0131] The laser irradiation device according to Embodiment 6 will be described. Illustrations and descriptions of matters common to the previously described embodiments will be simplified or omitted. This embodiment shares the same characteristics as the previously described embodiments in that the reflective surface for X scanning and the reflective surface for Y scanning are fixed to a rotatable, circular, two-dimensional deflector.

[0132] In the above embodiment, in order to guide the laser beam from the irradiation position P1 to the irradiation position P2, as shown in FIG. Figure 6 (a) Figure 6 As shown in (b), a light guide portion having four reflecting surfaces is used, but the structure of the light guide portion is not limited to this.

[0133] like Figure 16 (a) and Figure 16 As shown in (b), in this embodiment, the laser beam is guided from the irradiation position P1 to the irradiation position P2 by a light guide having three reflecting surfaces: a reflector 301B, a reflector 302B, and a reflector 303B. The reflector 301B is a reflector that reflects in the x direction, the reflector 303B is a reflector that reflects in the y direction, and the reflector 302B sets the reflection angle in both the x and y directions. According to this structure, the reflected image is distorted by 90°, and the direction of travel of the laser beam is changed by 90°. By providing three reflecting surfaces, the number of components can be reduced. In addition, some or all of the three reflecting surfaces can be composed of the internal total reflection surface of the prism.

[0134] [Implementation 7]

[0135] The object detection device according to Embodiment 7 will be described. Illustrations and descriptions of matters common to the previously described embodiments will be simplified or omitted. This embodiment shares the same characteristics as the previously described embodiments in that the reflective surface for X scanning and the reflective surface for Y scanning are fixed to a rotatable, circular, two-dimensional deflector.

[0136] The present embodiment is an object detection device including the laser irradiation device or the laser irradiation system according to any one of the above-described embodiments. Figure 17 This is a block diagram illustrating the basic structure of object detection device 400 according to this embodiment. Object detection device 400 includes a laser light source 101, a two-dimensional deflector 211, a controller 500, a light source control unit 501, a motor driver 502, a light sensor unit 503, a data processing unit 504, and an I / O unit 505.

[0137] Controller 500 is a computer for controlling the operation of each unit of object detection apparatus 400. I / O unit 505 is an input / output unit that communicatively connects external equipment (eg, an external computer or storage device) or an external network to object detection apparatus 400.

[0138] The laser light source 101 outputs a laser beam under the control of the light source control unit 501. The laser light source 101 preferably uses a laser diode in an invisible region such as infrared, but is not limited thereto and may also output a laser beam in a visible region.

[0139] The two-dimensional deflector 211 is a two-dimensional deflector according to any of the above-mentioned embodiments. The motor 212 driven under the control of the motor driving unit 502 rotates the disc-shaped two-dimensional deflector 211 to perform two-dimensional deflection scanning on the laser beam emitted from the laser light source 101 .

[0140] The laser light source 101, the light source control unit 501, the two-dimensional deflector 211, and the motor drive unit 502 operating under the control of the controller 500 constitute the laser irradiation device involved in any of the above-mentioned embodiments. Figure 17 It is not shown in the figure, but it can also be implemented as in embodiment 4 ( Figure 12 ) is provided with a projection lens 105 having a variable focal length, and the controller 500 controls the focal length of the projection lens 105.

[0141] The light-receiving sensor unit 503 is a light sensor sensitive to the wavelength range of the laser beam output by the laser light source 101. A CMOS image sensor or CCD sensor is preferably used. When the laser beam emitted by the object detection device 400 during deflection scanning strikes an object to be detected, the light-receiving sensor unit 503 detects the reflected light from the object. Alternatively, the light-receiving sensor unit 503 can be a time-of-flight sensor (TOF sensor) that measures the time it takes for a pulsed laser beam emitted from the laser light source 101 to be reflected from an object.

[0142] The data processing unit 504 calculates the position of the object to be detected based on the irradiation direction of the laser beam and the information of the return light detected by the light-receiving sensor unit 503. The data processing unit 504 can calculate the irradiation direction of the laser beam, that is, the direction of the object, based on the driving information of the motor driving unit 502 that controls the rotation of the two-dimensional deflector 211. The data processing unit 504 can calculate the distance to the object based on the TOF information measured by the light-receiving sensor unit 503. After calculating the position information of the object, the data processing unit 504 transmits the calculation result (detection information of the object) to the controller 500 or to the outside of the object detection device 400 via the I / O unit 505. The outside of the object detection device 400 can be, for example, a computer of an automatic driving system or a driving assistance system of a mobile body represented by an automobile.

[0143] According to this embodiment, a laser irradiation device with suppressed synchronization deviation between X scanning and Y scanning can be used to compactly configure a Lidar (Light Detection and Ranging) applicable to an object detection device or a distance measurement device.

[0144] [Other embodiments]

[0145] The present invention is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present invention. For example, all or part of the above-described different embodiments and examples may be combined and implemented.

[0146] For example, in the above embodiment, an example is shown in which, when the two-dimensional deflector rotates one circle, the laser beam is deflected and scanned in sequence along the first scanning line to the M-th scanning line (M is an integer greater than or equal to 2), which extend in the X direction and have different positions in the Z direction, to complete one frame of irradiation. However, if the period of the angular coordinates of the change in the inclined surface of the reflecting surface 213 and the reflecting surface 214 in the above embodiment is changed, the number of frames per rotation can be made different. For example, if the period of the angular coordinates of the change in the inclined surface is set to half of that in the above embodiment, the two-dimensional deflector can be configured in such a way that two frames of irradiation are performed during one rotation. In this way, the number of scanning frames corresponding to one rotation of the two-dimensional deflector can be arbitrarily set, and for example, a laser irradiation device can be configured that can perform high-speed frame scanning even at a low rotation speed.

[0147] The light guide portion that guides the laser beam reflected by the reflective surface 213 to the reflective surface 214 may include three or more reflective surfaces. The number of reflective surfaces is not limited to the three or four surfaces shown in the embodiments. In addition, the reflective surface may be a reflector, or an internal total reflection surface of a prism. Alternatively, a reflector and a prism may be combined to form the light guide portion. In addition, the light guide portion may include either or both a free-form reflective surface and a conjugate relay lens.

[0148] In the above embodiment, a two-dimensional deflector is illustrated in which the reflection surface 213 for inputting a laser beam from a laser light source is located on the outer side and the reflection surface 214 for outputting a two-dimensional deflected scanning laser beam is located on the inner side. However, the outer and inner sides may be opposite.

[0149] The two-dimensional deflector 211 may have the reflective surface 213 and the reflective surface 214 formed on a single substrate, or may be constructed using other methods. For example, the reflective surface 214 may be formed on a first substrate (a small-diameter circular plate), the reflective surface 213 may be formed on a second substrate (a large-diameter circular plate), and the first substrate may be bonded to the second substrate to form an integrated structure, thereby forming the two-dimensional deflector 211.

[0150] This specification discloses at least the following matters.

[0151] [Item 1]

[0152] A laser irradiation device comprising:

[0153] Laser light source; and

[0154] A two-dimensional deflector is used to deflect and scan the laser beam output by the laser light source in two dimensions in a first direction and a second direction.

[0155] The laser irradiation device is characterized in that

[0156] The two-dimensional deflector comprises:

[0157] A base body capable of rotating about a rotation axis;

[0158] a first reflecting surface arranged on the base along a circumference of a first radius centered on the rotation axis;

[0159] a second reflecting surface arranged on the base along a circumference of a second radius centered on the rotation axis; and

[0160] a light guide portion, guiding the laser beam reflected by the first reflection surface to the second reflection surface,

[0161] The first reflecting surface is configured such that an inclination angle relative to the rotation axis varies along a circumference of the first radius, and the inclination angle of the first reflecting surface is configured such that when the base body is continuously rotated, the laser beam is recursively deflected in the first direction.

[0162] The second reflecting surface is configured such that an inclination angle relative to the rotation axis varies along a circumference of the second radius, and the inclination angle of the second reflecting surface is configured such that, when the base body is continuously rotated, the laser beam is recursively deflected in the second direction.

[0163] [Item 2]

[0164] The laser irradiation device according to item 1 is characterized in that

[0165] When the base is continuously rotated, the laser beam reflected from the second reflection surface

[0166] Deflection scanning of one frame along M scanning lines is recursively repeated, wherein the M scanning lines are positioned differently in the second direction and extend along the first direction, and M is an integer greater than or equal to 2.

[0167] [Item 3]

[0168] The laser irradiation device according to item 1 or 2 is characterized in that

[0169] The first reflecting surface is configured to include sections formed by equally dividing the circumference M of the first radius, and the inclination angle of the first reflecting surface changes in the same manner in each section.

[0170] [Item 4]

[0171] The laser irradiation device according to item 3 is characterized in that

[0172] The second reflecting surface is configured to include sections formed by equally dividing a circle M having the second radius. The inclination angle of the second reflecting surface is constant in each section, and the inclination angle of the second reflecting surface is different in each section.

[0173] [Item 5]

[0174] The laser irradiation device according to any one of items 1 to 3 is characterized in that

[0175] The second reflecting surface is configured such that an inclination angle increases monotonically along a circumference of the second radius.

[0176] [Item 6]

[0177] The laser irradiation device according to any one of items 1 to 5 is characterized in that

[0178] The light guide portion includes at least three or more reflective surfaces.

[0179] [Item 7]

[0180] The laser irradiation device according to any one of items 1 to 6 is characterized in that

[0181] The light guide portion includes a prism having a total internal reflection surface.

[0182] [Item 8]

[0183] The laser irradiation device according to any one of items 1 to 7 is characterized in that

[0184] The light guide portion includes a reflecting surface having a free-curved shape obtained by twisting a flat surface.

[0185] [Item 9]

[0186] The laser irradiation device according to any one of items 1 to 8 is characterized in that

[0187] The laser beam output by the laser light source is irradiated onto the first reflecting surface at a first irradiation position.

[0188] The laser beam reflected by the first reflecting surface is guided by the light guide portion and irradiated onto the second reflecting surface at a second irradiation position.

[0189] A line connecting the first irradiation position and the rotation axis is substantially orthogonal to a line connecting the second irradiation position and the rotation axis.

[0190] [Item 10]

[0191] The laser irradiation device according to item 9 is characterized in that

[0192] The light guide unit includes a conjugate relay lens for bringing the first irradiation position and the second irradiation position into a conjugate relationship.

[0193] [Item 11]

[0194] A laser irradiation system, characterized by comprising:

[0195] The laser irradiation device according to any one of items 1 to 10; and

[0196] Projection lens with variable focal length.

[0197] [Item 12]

[0198] An object detection device, characterized by comprising:

[0199] The laser irradiation device according to any one of items 1 to 10; and

[0200] The light receiving sensor detects reflected light of the laser beam output from the laser irradiation device after being reflected by an object.

[0201] [Item 13]

[0202] A distance measuring device, characterized by comprising:

[0203] The laser irradiation device according to any one of items 1 to 10; and

[0204] The light receiving sensor detects reflected light of the laser beam output from the laser irradiation device after being reflected by an object.

Claims

1. A laser irradiation device comprising: Laser light source; and A two-dimensional deflector is used to deflect and scan the laser beam output by the laser light source in two dimensions in a first direction and a second direction. The laser irradiation device is characterized in that The two-dimensional deflector comprises: A base body capable of rotating about a rotation axis; a first reflecting surface arranged on the base along a circumference of a first radius centered on the rotation axis; a second reflecting surface arranged on the base along a circumference of a second radius centered on the rotation axis; and a light guide portion, guiding the laser beam reflected by the first reflection surface to the second reflection surface, The first reflecting surface is configured such that an inclination angle relative to the rotation axis varies along a circumference of the first radius, and the inclination angle of the first reflecting surface is configured such that when the base body is continuously rotated, the laser beam is recursively deflected in the first direction. The second reflecting surface is configured such that an inclination angle relative to the rotation axis varies along a circumference of the second radius, and the inclination angle of the second reflecting surface is configured such that, when the base body is continuously rotated, the laser beam is recursively deflected in the second direction.

2. The laser irradiation device according to claim 1, wherein When the base is continuously rotated, the laser beam reflected from the second reflection surface Deflection scanning of one frame along M scanning lines is recursively repeated, wherein the M scanning lines are positioned differently in the second direction and extend along the first direction, and M is an integer greater than or equal to 2.

3. The laser irradiation device according to claim 2, characterized in that The first reflecting surface is configured to include sections formed by equally dividing the circumference M of the first radius, and the inclination angle of the first reflecting surface changes in the same manner in each section.

4. The laser irradiation device according to claim 3, characterized in that The second reflecting surface is configured to include sections formed by equally dividing a circle M having the second radius. The inclination angle of the second reflecting surface is constant in each section, and the inclination angle of the second reflecting surface is different in each section.

5. The laser irradiation device according to claim 1, wherein The second reflecting surface is configured such that an inclination angle increases monotonically along a circumference of the second radius.

6. The laser irradiation device according to any one of claims 1 to 5, characterized in that The light guide portion includes at least three or more reflective surfaces.

7. The laser irradiation device according to any one of claims 1 to 5, characterized in that The light guide portion includes a prism having a total internal reflection surface.

8. The laser irradiation device according to any one of claims 1 to 5, characterized in that The light guide portion includes a reflecting surface having a free-curved shape obtained by twisting a flat surface.

9. The laser irradiation device according to any one of claims 1 to 5, characterized in that The laser beam output by the laser light source is irradiated onto the first reflecting surface at a first irradiation position. The laser beam reflected by the first reflecting surface is guided by the light guide portion and irradiated onto the second reflecting surface at a second irradiation position. A line connecting the first irradiation position and the rotation axis is substantially orthogonal to a line connecting the second irradiation position and the rotation axis.

10. The laser irradiation device according to claim 9, characterized in that The light guide unit includes a conjugate relay lens for bringing the first irradiation position and the second irradiation position into a conjugate relationship.

11. A laser irradiation system, characterized in that: have: The laser irradiation device according to any one of claims 1 to 5; and Projection lens with variable focal length.

12. An object detection device, characterized in that: have: The laser irradiation device according to any one of claims 1 to 5; and The light receiving sensor detects reflected light of the laser beam output from the laser irradiation device after being reflected by an object.

13. A distance measuring device, characterized in that: have: The laser irradiation device according to any one of claims 1 to 5; and The light receiving sensor detects reflected light of the laser beam output from the laser irradiation device after being reflected by an object.

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