JP2018185400A - Laser scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact laser scanner which can scan a wide area.SOLUTION: A laser scanner includes a circular stage 23, a plurality of light-emitting elements 11C for emitting laser beams, a plurality of light-receiving elements 13A arranged adjacent to the light-emitting elements 11C in a peripheral end of the stage 23, a circular mirror array 12 arranged above the stage 23 and having a plurality of concave mirrors, and a driving unit 14 which is connected to the mirror array 12 via a rotation axis, to rotate the mirror array 12. The plurality of concave mirrors, which are arranged in a peripheral end of the mirror array 12 so as to reflect laser beams, have different shapes.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a laser scanning device mounted on a vehicle or the like, for example, a laser scanning device using infrared laser light.

  Devices for automatically driving vehicles or assisting driving of vehicles have been actively developed. Further, LIDAR (Light Detection and Ranging) mounted on a vehicle or the like is known. The LIDAR is a sensor that detects an object around the vehicle with high accuracy using a laser beam, and is one of the sensors necessary for the practical use of automatic driving.

  As the LIDAR scanning method, for example, a method using a polygon mirror, a MEMS (Micro Electro Mechanical Systems) mirror, or a galvanometer mirror is used. However, these methods tend to increase the cost and size of the laser scanning device. For this reason, it is desired to reduce the cost and size of the laser scanning device.

JP 2010-38859 A JP 2009-216789 A

  The present invention provides a laser scanning device that can scan a wide area and can be miniaturized.

  A laser scanning device according to one embodiment of the present invention includes a circular stage, a plurality of light-emitting elements that are provided at a peripheral end portion of the stage, and that are adjacent to the plurality of light-emitting elements. A plurality of light receiving elements provided at a peripheral edge of the stage, a circular mirror array disposed above the stage and having a plurality of concave mirrors, and connected to the mirror array via a rotating shaft, And a drive unit for rotating the array. The plurality of concave mirrors are provided at the peripheral end of the mirror array so as to reflect the laser light, and are different in shape from each other.

  According to the present invention, it is possible to provide a laser scanning device that can scan a wide area and can be miniaturized.

1 is a block diagram of a laser scanning device according to an embodiment of the present invention. The perspective view of a laser scanner. FIG. 3 is a bottom view of the mirror array shown in FIG. 2. FIG. 4 is a cross-sectional view of the laser scanning device along the line IV-IV in FIG. 2. The exploded view of a laser scanning device. The top view of a light source part, a light-receiving part, and a stage. Sectional drawing of a light source part and a stage. The figure explaining the waveform of the laser beam by a laser scanning apparatus. The figure explaining the operation | movement which scans the laser beam based on 1st Example. The figure explaining the operation | movement which scans the laser beam based on 1st Example. The figure explaining the operation | movement which scans the laser beam based on 2nd Example. The figure explaining the line scanning which concerns on 3rd Example.

  Hereinafter, embodiments will be described with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and ratios of the drawings are not necessarily the same as actual ones. Further, even when the same portion is represented between the drawings, the dimensional relationship and ratio may be represented differently. In particular, the following embodiments exemplify an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention depends on the shape, structure, arrangement, etc. of components. Is not specified. In the following description, elements having the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

[1] Circuit Configuration of Laser Scanning Device FIG. 1 is a block diagram of a laser scanning device 10 according to an embodiment of the present invention.

  The laser scanning device 10 is also called LIDAR (Light Detection and Ranging). LIDAR scans a certain range, for example, in front of the vehicle using laser light, and detects laser light reflected by an object in this scanning range. And LIDAR detects a target object using the transmitted laser beam and the received laser beam, or measures the distance from a vehicle to a target object.

  The laser scanning device 10 is disposed on the top of the vehicle, such as a roof or a bonnet. In addition, the laser scanning device 10 may be provided on the front side of the vehicle (for example, the front bumper or the front grill), the rear side of the vehicle (for example, the rear bumper or the rear grill), and / or the side of the vehicle (for example, the side of the front bumper) ).

  The laser scanning device 10 includes a light source unit 11, a mirror array 12, a light receiving unit 13, a mirror driving unit 14, a pulse timing control unit 15, a distance calculation unit 16, and a main control unit 17.

  The light source unit 11 generates (emits) a plurality of laser beams toward the mirror array 12. The light source unit 11 includes a number of light emitting elements corresponding to a plurality of laser beams. As will be described later, the mirror array 12 includes a plurality of concave mirrors. The light source unit 11 can emit a number of laser beams corresponding to a plurality of concave mirrors. As the laser light, for example, infrared laser light (for example, wavelength λ = 905 nm) is used. The light source unit 11 generates laser light as a pulse signal having a predetermined frequency.

  The mirror array 12 includes a plurality of reflecting members having different shapes. The plurality of reflecting members are constituted by concave mirrors, for example. The outer shape of the mirror array 12 is a circle. The mirror array 12 can be rotated by a motor. The mirror array 12 reflects a plurality of laser beams from the light source unit 11 and emits the laser beams toward the surroundings thereof.

  The light receiving unit (detection circuit) 13 detects the laser light reflected by the object 2. The light receiving unit 13 includes a plurality of light receiving elements corresponding to the plurality of light emitting elements included in the light source unit 11. The light receiving element is composed of, for example, an infrared sensor. The infrared sensor includes a photodiode or a complementary metal oxide semiconductor (CMOS) photosensor. In addition, an infrared camera may be used as the light receiving element.

  The mirror driving unit 14 drives the mirror array 12 and rotates the mirror array 12 via a rotation axis. The mirror driving unit 14 includes a motor that rotates the mirror array 12, a rotary encoder (rotary encoder) that detects position information of the mirror array 12, and the like. Information such as the rotational displacement amount, rotational speed, and rotational angle of the mirror array 12 is converted into an electrical signal by a rotary encoder (not shown) included in the mirror drive unit 14. Thereby, the position of each concave mirror of the mirror array 12 can be detected and specified.

  The pulse timing control unit 15 controls the operation of the light source unit 11. The light source unit 11 emits laser light (that is, pulsed laser light) as a pulse signal. The pulse timing control unit 15 controls the timing of pulses included in the laser light. The pulse timing includes the period of the pulse signal, the frequency of the pulse signal, and the pulse width.

  The distance calculation unit 16 receives the timing information of the transmitted laser beam from the pulse timing control unit 15, receives the information of the emission angle in each of the horizontal direction and the vertical direction from the main control unit 17, and receives the timing of the received laser beam. Information and light intensity information are received from the light receiving unit 13. The distance calculation unit 16 calculates the distance from the vehicle to the object using these pieces of information. Specifically, the distance calculation unit 16 calculates a linear distance, a horizontal distance, and a vertical distance using information on the emission angle. In addition, the distance calculation unit 16 calculates the relative coordinates of the target object using information on the emission angle and the like. The distance and / or relative coordinates calculated by the distance calculation unit 16 can be output to the outside as data DOUT, for example.

  The main control unit 17 comprehensively controls the entire operation of the laser scanning device 10. In particular, the main control unit 17 controls the rotational position of the mirror array 12 and the like via the mirror driving unit 14.

[2] Configuration of Laser Scanning Device 10 Next, the configuration of the laser scanning device 10 will be described. FIG. 2 is a perspective view of the laser scanning device 10. FIG. 3 is a bottom view of the mirror array 12 shown in FIG. That is, FIG. 3 shows only the mirror array 12 extracted and viewed from below. 4 is a cross-sectional view of the laser scanning device 10 taken along line IV-IV in FIG. FIG. 5 is an exploded view of the laser scanning device 10.

  The laser scanning device 10 includes a mirror array 12, a bottom plate 20, a motor 21, a rotating shaft 22, a stage 23, a light source 11A, and screws 24-1 to 24-4.

  The motor 21 rotates the mirror array 12. The rotation operation of the motor 21 is controlled by the mirror driving unit 14. The motor 21 is placed on the circular bottom plate 20. A rotation shaft 22 is attached to the motor 21, and the mirror array 12 is fixed to the rotation shaft 22.

  The stage 23 has a circular shape. The stage 23 is fixed on the bottom plate 20 with screws 24-1 and 24-2. The mirror array 12 is disposed above the stage 23. The motor 21 is housed in an opening 23A provided in the stage 23, and is fixed to the stage 23 by screws 24-3 and 24-4. The screws 24-3 and 24-4 pass through the protrusions 21A and 21B provided in the motor 21 (specifically, the motor case), and fix the protrusions 21A and 21B and the stage 23. The rotating shaft 22 passes through an opening 23 </ b> B provided at the center of the stage 23. The diameter of the circular opening 23 </ b> B is set so that the rotating shaft 22 does not contact the stage 23.

  The stage 23 (specifically, the light source unit 11 provided in the stage 23) emits a plurality of laser beams toward the mirror array 12. The stage 23 (specifically, the light receiving unit 13 provided in the stage 23) detects a plurality of laser beams incident from the mirror array 12. A more specific configuration of the stage 23 will be described later.

  The light source 11A included in the light source unit 11 irradiates the stage 23 with laser light. The method of fixing the light source 11A to the stage 23 can be arbitrarily designed.

  The mirror array 12 has a circular shape. The mirror array 12 includes a circular base 12A and a plurality of concave mirrors 12B. In the present embodiment (FIG. 3), as an example, the mirror array 12 includes twelve concave mirrors 12B-1 to 12B-12. The number of concave mirrors provided in the mirror array 12 can be set to an arbitrary number of 2 or more.

  The base 12 </ b> A has an opening 12 </ b> C at the center thereof, and the opening 12 </ b> C of the base 12 </ b> A is fixed to the rotating shaft 22. Thereby, the mirror array 12 can rotate around the rotation axis 22. The mirror array 12 is arranged with a gap from the stage 23 so as not to contact the stage 23.

  The plurality of concave mirrors 12B are provided at the peripheral end of the base 12A. The concave mirror 12B reflects laser light incident in the vertical direction from the stage 23 toward the periphery (outside) of the mirror array 12. The concave mirror 12B reflects the laser light reflected by the object toward the light receiving element of the stage 23. The plurality of concave mirrors 12 </ b> B are arranged at equal intervals along the circumference of the mirror array 12.

  The plurality of concave mirrors 12B have different shapes. The shape of the concave mirror 12B includes its height and its thickness. The thickness of the concave mirror is the length of the concave mirror in the horizontal direction toward the center of the mirror array 12. In other words, the plurality of concave mirrors 12B have different curvature radii or focal lengths. Specifically, the concave mirrors 12B-1 to 12B-12 increase in height and increase in thickness in this order. Further, the concave mirrors 12B-1 to 12B-12 have a smaller radius of curvature and a shorter focal length in this order.

  The base material 12A has a plurality of curved depressions (grooves) at its peripheral end, and the plurality of concave mirrors 12B are provided in the curved depressions formed on the base 12A. The base 12A is made of, for example, a resin. For example, the concave mirror 12B is configured by performing mirror processing (mirror processing) on a curved recess formed on the base 12A by vapor deposition or sputtering. The concave mirror 12B may be configured by attaching a reflective film (reflective member) to a curved depression formed on the base 12A. The concave mirror 12B may be configured by attaching a metal processed into a concave surface (for example, aluminum (Al)) to a curved recess formed in the base 12A. The mirror array 12 may be configured by vapor-depositing aluminum (Al) on the entire base material 12A which is molded of resin and has a plurality of curved depressions.

[3] Configuration of Light Source Unit 11 and Light Receiving Unit 13 Next, the configuration of the light source unit 11 and the light receiving unit 13 will be described. The light source unit 11 and the light receiving unit 13 are provided in the stage 23. FIG. 6 is a plan view of the light source unit 11, the light receiving unit 13, and the stage 23. FIG. 7 is a cross-sectional view of the light source unit 11 and the stage 23.

  The light source unit 11 includes a light source (light emitting element) 11A, a plurality of optical waveguides 11B (11B-1 to 11B-12), and a plurality of condenser lenses 11C (11C-1 to 11C-12). Each of the plurality of optical waveguides 11B and the plurality of condenser lenses 11C is provided in a number corresponding to the number of the plurality of concave mirrors 12B.

  The light source 11A emits laser light. The light source 11A is composed of a laser element. The light source 11 </ b> A is attached to any part of the stage 23.

  The optical waveguide 11B guides the laser light emitted from the light source 11A to the condenser lens 11C. For example, an optical fiber is used as the optical waveguide 11B. The optical fiber includes a core and a clad covering the core. The refractive index of the core is set higher than the refractive index of the cladding. In FIG. 6, the optical waveguide 11B is shown by a straight line, but the path of the optical waveguide can be arbitrarily designed.

  The light source 11A may be provided for each optical waveguide 11B. That is, the light source unit 11 may include a plurality of light sources 11A corresponding to the plurality of concave mirrors 12B.

  The plurality of condensing lenses 11 </ b> C are arranged at equal intervals along the circumference of the stage 23. Each of the plurality of condensing lenses 11C is provided corresponding to the plurality of concave mirrors 12B. That is, when the mirror array 12 is stopped at a predetermined position (for example, a position in a predetermined initial state), the condenser lens 11C is disposed so as to face the corresponding concave mirror 12B. The plurality of condenser lenses 11 </ b> C have the same distance from the center of the stage 23.

  The condenser lens 11C transmits the laser light from the optical waveguide 11B and emits it toward the concave mirror 12B. In addition, the traveling direction of the laser light emitted from the condenser lens 11 </ b> C is set in a direction perpendicular to the stage 23. For example, a biconvex lens is used as the condenser lens 11C. In addition, when the laser beam emitted from the optical waveguide 11B has high directivity (that is, coherent and narrow laser beam), the condensing lens 11C is unnecessary. In addition, a light emitting element that emits laser light may be disposed directly at the position of the condenser lens 11C.

  The light receiving unit 13 includes a plurality of light receiving elements 13A (13A-1 to 13A-12). The plurality of light receiving elements 13 </ b> A are arranged at equal intervals along the circumference of the stage 23. The plurality of light receiving elements 13A are provided in a number corresponding to the number of the plurality of concave mirrors 12B. The light receiving element 13A is disposed in proximity to the corresponding condenser lens 11C. The plurality of light receiving elements 13A have the same distance from the center of the stage 23. The light receiving element 13A detects the laser light reflected by the concave mirror 12B.

[4] Operation of Laser Scanning Device 10 [4-1] Basic Operation of Laser Scanning Device 10 FIG. 8 is a diagram for explaining the waveform of laser light by the laser scanning device 10. The upper side of FIG. 8 is a transmission waveform, and the lower side of FIG. 8 is a reception waveform. The horizontal axis in FIG. 8 is time, and the vertical axis in FIG. 8 is intensity (light intensity). FIG. 8 shows the operation of one light emitting element (element composed of the light source 11A, one optical waveguide 11B, and one condenser lens 11C) and one light receiving element 13A corresponding thereto.

  The light source 11A emits a laser beam composed of a pulse signal. That is, the light source 11A emits a plurality of laser beams in a time division manner. The pulse timing control unit 15 controls the operation of the light source 11A, and controls the cycle and pulse width of the laser light. The laser scanning device 10 transmits laser light as a pulse signal.

  It is assumed that the pulse signal has a period P and a pulse width W. A delay amount Δ, which is a time from when one pulse is transmitted to when a pulse reflected by an object is received, and a light velocity C are set. The delay amount Δ is calculated by “Δ = 2L / C”. The distance calculation unit 16 calculates the distance from the vehicle to which the laser scanning device 10 is attached to the object using the delay amount Δ.

  For example, it is assumed that the pulse width W = 10 nsec and the period P = 10 μsec (that is, the frequency f = 100 kHz). When the delay amount Δ = 67 nsec, the distance L = 10 m is calculated. By such an operation, the object can be detected and the distance to the object can be calculated.

[4-2] First Example Next, an operation for scanning a laser beam will be described. The light source unit 11 emits twelve laser beams in the vertical direction from the positions of the condenser lenses 11C-1 to 11C-12. The mirror drive unit 14 rotates the mirror array 12 and detects the positions of the concave mirrors 12B-1 to 12B-12 included in the mirror array 12 according to the rotation operation of the mirror array 12. Each of the concave mirrors 12B-1 to 12B-12 sequentially reflects the twelve laser beams emitted from the condenser lenses 11C-1 to 11C-12. Thereby, the mirror array 12 can transmit laser beams at 12 azimuth angles.

  9 and 10 are diagrams for explaining the operation of scanning the laser beam according to the first embodiment. FIG. 9 shows the shape of the concave mirrors 12B-1 to 12B-12 in the cross-sectional direction and the state of the laser light reflected by the concave mirrors 12B-1 to 12B-12. FIG. 10 illustrates an example of a position where the laser light strikes the concave mirror 12B when the mirror array 12 is viewed from below. The first embodiment is an operation of scanning the laser beam in the vertical direction at each of the 12 azimuth angles corresponding to the condenser lenses 11C-1 to 11C-12.

  The light source unit 11 emits a pulsed laser beam from each of the condenser lenses 11C-1 to 11C-12 every time the mirror array 12 rotates 30 degrees.

  The laser light emitted from the condenser lens 11C-1 is reflected by, for example, the concave mirror 12B-1 and emitted toward the outside of the mirror array 12. Subsequently, the mirror array 12 continuously rotates 30 degrees counterclockwise, and the laser beam emitted from the condenser lens 11C-1 is reflected by the concave mirror 12B-2 and emitted toward the outside of the mirror array 12. The Subsequently, the mirror array 12 continuously rotates counterclockwise by 60 degrees, and the laser light emitted from the condenser lens 11C-1 is reflected by the concave mirror 12B-3 and emitted toward the outside of the mirror array 12. The Thereafter, the laser light emitted from the condenser lens 11 </ b> C- 1 is sequentially reflected by the concave mirrors 12 </ b> B- 4 to 12 </ b> B- 12 and emitted toward the outside of the mirror array 12.

  Similarly, the laser beams emitted from the condenser lenses 11C-2 to 11C-12 are sequentially reflected by the concave mirrors 12B-1 to 12B-12 and emitted toward the outside of the mirror array 12.

  Further, the mirror array 12 is further rotated in units of circumference, so that the laser beams emitted from the condenser lenses 11C-2 to 11C-12 are repeatedly reflected by the concave mirrors 12B-1 to 12B-12. Thereby, the scanning operation is performed at 12 azimuth angles.

  Here, the concave mirror 12B-1 and the concave mirror 12B-2 have different shapes. Specifically, the radius of curvature of the concave mirror 12B-2 is smaller than the radius of curvature of the concave mirror 12B-1. Therefore, the laser beam reflected by the concave mirror 12B-2 has a different emission angle from the laser beam reflected by the concave mirror 12B-1. For example, let the horizontal direction be the outgoing angle θ = 0, the upper side from the horizontal direction is the positive outgoing angle “+ θ”, and the lower side from the horizontal direction is the negative outgoing angle “−θ”. In this case, the emission angle of the laser beam reflected by the concave mirror 12B-2 is smaller than the emission angle of the laser beam reflected by the concave mirror 12B-1.

  Similarly, the emission angle of the laser beam reflected by the concave mirror 12B-2 to the concave mirror 12B-12 changes. Thereby, the laser scanning device 10 can scan the laser beam at the scanning angle “2θ” in the vertical direction.

[4-3] Second Embodiment In the second embodiment, the emission angle in the horizontal direction is changed by controlling the position at which the laser beam strikes the concave mirror 12B.

  FIG. 11 is a diagram for explaining the operation of scanning the laser beam according to the second embodiment. FIG. 11 shows the state of the laser light reflected by the concave mirror 12B-1 when the mirror array 12 is viewed from below. The explanation of directions in FIG. 11 corresponds to the case where the mirror array 12 is viewed from below.

  The light source unit 11 emits a plurality of pulsed laser beams at predetermined intervals. The mirror drive unit 14 controls the position of the concave mirror 12B while rotating the mirror array 12. The position of the concave mirror 12B is defined by the relationship with the position of the condenser lens 11C.

  FIG. 11A shows an operation in which the concave mirror 12B-1 emits (that is, reflects) laser light at the emission angle θ1. The mirror driving unit 14 controls the position of the concave mirror 12B-1 so that the laser beam is irradiated to the right side from the center of the concave mirror 12B-1. That is, the mirror driving unit 14 is arranged so that the position of the condensing lens 11C-1 is on the right side of the center of the concave mirror 12B-1 at the timing when the light source unit 11 emits laser light from the condensing lens 11C-1, for example. The position of the concave mirror 12B-1 is controlled.

  FIG. 11B shows an operation in which the concave mirror 12B-1 emits laser light at an emission angle θ = 0. The mirror driving unit 14 controls the position of the concave mirror 12B-1 so that the laser beam is irradiated to the center of the concave mirror 12B-1.

  FIG. 11C shows an operation in which the concave mirror 12B-1 emits laser light at the emission angle θ2. The mirror driving unit 14 controls the position of the concave mirror 12B-1 so that the laser beam is irradiated to the left side from the center of the concave mirror 12B-1. That is, the mirror driving unit 14 is arranged so that the position of the condensing lens 11C-1 is on the left side of the center of the concave mirror 12B-1 at the timing when the light source unit 11 emits laser light from the condensing lens 11C-1, for example. The position of the concave mirror 12B-1 is controlled.

  If the exit angle θ1 in FIG. 11A is positive and the exit angle θ = 0 in FIG. 11B, the exit angle θ2 in FIG. 11C is negative. The outgoing angle in the horizontal direction is also called the azimuth angle. By controlling the position of the laser beam incident on the concave mirror 12B, the laser beam can be scanned in the horizontal direction at a certain emission angle.

[4-4] Third Example In the third example, the same concave mirror 12B is continuously irradiated with a plurality of laser beams (a plurality of pulses), thereby scanning the same height in a line (line scanning). I am doing so.

  For the operation of scanning the laser beam in the horizontal direction according to the third embodiment, FIG. 11 can be used. For example, the light source unit 11 emits a plurality of laser beams composed of pulses in a period in which the concave mirror 12B-1 passes above the condenser lens 11C-1. FIG. 11 shows an example in which a laser beam composed of three pulses is transmitted.

  Since the mirror array 12 is rotating, a plurality of laser beams are incident on the concave mirror 12B-1 at different positions. The azimuth angle at which the laser light is reflected differs depending on the shape of the concave mirror 12B-1.

  FIG. 12 is a diagram for explaining line scanning according to the third embodiment. In FIG. 12, the height H1 represents the position (scanning position) of the line scanned by the concave mirror 12B-1. A line representing the height H1 in FIG. 12 is a set of a plurality of scanning points. A scanning point corresponds to one pulse in FIG.

  In FIG. 12, the lines corresponding to the heights H2 to H12 correspond to the scanning positions of the concave mirrors 12B-2 to 12B-12.

  In the third embodiment, a plurality of points can be scanned in the horizontal direction at the same height. That is, the horizontal direction can be scanned with higher density. In addition, the density of scanning points can be increased over all directions. That is, three-dimensional scan information can be acquired at 360 degrees.

[5] Effects of the Embodiment As described in detail above, in the present embodiment, the laser scanning device 10 is provided on the circular stage 23 and the peripheral end portion of the stage 23, and a plurality of light emitting elements 11C that emit laser light. A circular mirror array having a plurality of light receiving elements 13A provided at the peripheral end of the stage 23 and adjacent to the plurality of light emitting elements 11C, and a plurality of concave mirrors 12B disposed above the stage 23. 12 and a drive unit 14 that is connected to the mirror array 12 via a rotating shaft 22 and rotates the mirror array 12. The plurality of concave mirrors 12B are provided at the peripheral end of the mirror array 12 so as to reflect the laser beams from the plurality of light emitting elements 11C. The plurality of concave mirrors 12B have different shapes.

  Therefore, according to the present embodiment, it is possible to scan all directions using laser light by continuously rotating a plurality of concave mirrors 12B having different shapes. Further, it is possible to scan in the vertical direction at each of a plurality of azimuth angles. Therefore, a laser apparatus capable of scanning in the horizontal direction and the vertical direction using the laser light can be realized.

  Also, three-dimensional information can be acquired about the periphery of the laser scanning device 10. That is, the laser scanning device 10 capable of scanning a wider area can be realized.

  Moreover, horizontal line scanning can be performed by allowing a plurality of laser beams to continuously enter one concave mirror 12B. Therefore, all directions can be scanned with high-density scanning points.

  In addition, the laser scanning device 10 can be configured with relatively simple elements. Thereby, size reduction of the laser scanning apparatus 10 is possible. Further, the cost of the laser scanning device 10 can be reduced.

  In the said embodiment, although the mirror array showed the structure provided with a some concave mirror, you may comprise a mirror (reflective member) with optical elements other than a concave mirror. For example, instead of the concave mirror, the reflecting member may be composed of a plurality of convex mirrors having different curvature radii.

  In the above embodiment, infrared laser light is used as laser light handled by the laser scanning device. However, the present invention is not limited to this, and the laser scanning device according to this embodiment can be applied to light other than infrared laser light.

  In the above embodiment, a laser scanning device mounted on a vehicle has been described. However, the present invention is not limited to this, and can be applied to various electronic devices having a function of scanning with laser light.

  The present invention is not limited to the above embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Further, the above embodiments include inventions at various stages, and are obtained by appropriately combining a plurality of constituent elements disclosed in one embodiment or by appropriately combining constituent elements disclosed in different embodiments. Various inventions can be configured. For example, even if some constituent elements are deleted from all the constituent elements disclosed in the embodiments, the problems to be solved by the invention can be solved and the effects of the invention can be obtained. Embodiments made can be extracted as inventions.

  DESCRIPTION OF SYMBOLS 10 ... Laser scanning apparatus, 11 ... Light source part, 11A ... Light source, 11B ... Optical waveguide, 11C ... Condensing lens, 12 ... Mirror array, 12B ... Concave mirror, 13 ... Light receiving part, 13A ... Light receiving element, 14 ... Mirror drive part , 15 ... Pulse timing control unit, 16 ... Distance calculation unit, 17 ... Main control unit, 20 ... Bottom plate, 21 ... Motor, 22 ... Rotating shaft, 23 ... Stage

Claims (6)

A circular stage,
A plurality of light emitting elements provided at a peripheral end of the stage and emitting laser light;
A plurality of light receiving elements provided at a peripheral end of the stage so as to be adjacent to the plurality of light emitting elements,
A circular mirror array disposed above the stage and having a plurality of concave mirrors;
A drive unit connected to the mirror array via a rotation axis and rotating the mirror array;
Comprising
The plurality of concave mirrors are provided at a peripheral end of the mirror array so as to reflect the laser light, and have different shapes from each other. The laser scanning device according to claim 1, wherein the plurality of concave mirrors have different heights. The laser scanning device according to claim 1, wherein the plurality of concave mirrors have different curvature radii. The first light emitting element continuously emits a plurality of pulsed laser beams,
The laser scanning device according to any one of claims 1 to 3, wherein the driving unit reflects a plurality of laser beams from the first light emitting element to a first concave mirror. The plurality of light emitting elements are arranged at equal intervals along the circumference of the stage,
The laser scanning device according to claim 1, wherein the plurality of concave mirrors are arranged at equal intervals along a circumference of the mirror array. A light source that emits laser light;
Each of the plurality of light emitting elements includes an optical waveguide and an optical element,
One end of the optical waveguide receives laser light from the light source,
The laser scanning device according to claim 1, wherein the optical element emits laser light emitted from the other end of the optical waveguide toward one of the plurality of concave mirrors.