WO2018147453A1 - Scanning optical system and laser radar device - Google Patents
Scanning optical system and laser radar device Download PDFInfo
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- WO2018147453A1 WO2018147453A1 PCT/JP2018/004754 JP2018004754W WO2018147453A1 WO 2018147453 A1 WO2018147453 A1 WO 2018147453A1 JP 2018004754 W JP2018004754 W JP 2018004754W WO 2018147453 A1 WO2018147453 A1 WO 2018147453A1
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- light
- scanning
- mirror
- light receiving
- light source
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
- G02B26/12—Scanning systems using multifaceted mirrors
Definitions
- the present invention relates to a scanning optical system for detecting return light from an object while scanning a projection beam, and a laser radar apparatus incorporating the scanning optical system.
- a distance measuring device that detects a distance to an object by irradiating laser light while scanning in two dimensions and detecting reflected light returned from an object existing within the scanning range is known (for example, , See Patent Document 1).
- high power is obtained by collecting laser outputs from a plurality of light sources at one point.
- the present invention has been made in view of the above-mentioned problems of the background art, and provides a scanning optical system and a laser radar device that can detect at a long distance while solving problems relating to eye-safety and the like. Objective.
- a scanning optical system reflecting one aspect of the present invention includes a plurality of light sources and a collimator unit that each receives light from the light sources.
- System a scanning mirror that reflects the light from the light projecting system as a light projection beam and scans in the main scanning direction, a light receiving lens to which the return light from the scanning mirror is incident, and a return light that has passed through the light receiving lens is incident
- a plurality of light sources arranged at different positions in a direction corresponding to the sub-scanning direction orthogonal to the main scanning direction, and the light receiving elements arranged to detect return light corresponding to the plurality of light sources.
- the light projecting beams are emitted so that the positions of the light projecting fields of the light sources in the sub-scanning direction are different from each other.
- the light source corresponding to the field of view is different. It emits light at the timing.
- the light projection field is a range on the scanning region of the beam emitted from the light source.
- the range of the beam corresponding to each light source is defined as a group of light projection fields.
- a laser radar device reflecting one aspect of the present invention includes the above-described scanning optical system and detects an object based on return light.
- FIGS. 2A and 2B are a side view and a plan view for explaining the structure of the scanning optical system. It is a conceptual diagram explaining an interface circuit and its periphery among the laser radar apparatuses of FIG. 4A and 4B correspond to FIGS. 2A and 2B, and are a side view and a plan view in which the light projecting system and the light receiving system are enlarged.
- 5A to 5C are a front view, a side view, and a plan view around the light emitting surface of the first light source
- FIGS. 5D to 5F are a front view, a side view, and a plan view around the light emitting surface of the second light source.
- FIG. 6A is a diagram for explaining a projection state of the projection beam to a distant place
- FIG. 6B is a conceptual diagram for explaining a path such as intersection of the projection beam and vertical inversion. It is a figure explaining the state of a light receiving element.
- FIG. 8A is a diagram for explaining the first light emission timing of the light source
- FIG. 8B is a diagram for explaining the second light emission timing of the light source. It is a figure explaining the light emission timing of the light source of the laser radar apparatus in 2nd Embodiment.
- FIG. 10A is a diagram for explaining the projection pattern of the light source of the laser radar device according to the third embodiment
- FIG. 10B is a diagram for explaining the light emission timing of the light source.
- 11A to 11C are diagrams for explaining the projection field of view and the light emission timing of the light source of the laser radar device of FIG. 10A.
- 12A and 12B are a side view and a plan view illustrating the structure of the scanning optical system in the fourth embodiment.
- 13A and 13B are a side view and a plan view for explaining the structure of a scanning optical system in the fifth embodiment. It is the schematic explaining the laser radar apparatus which concerns on 6th Embodiment.
- the light projecting system 10 projects the laser light L1 that is the source of the light projecting beam onto the scanning mirror 31 of the rotary reflector 30 described later.
- the detailed structure of the light projecting system 10 will be described later.
- the light receiving system 20 receives the return light L2 reflected from the detection target OB incident through the optical window 63 of the exterior component 60, that is, the return light L2, and reflected by the scanning mirror 31 of the rotary reflection unit 30. To do. More specifically, when there is a detection target OB such as an object in the detection region, the laser light (projection beam) L1 emitted from the laser radar device 100 is reflected by the detection target OB and reflected by the detection target OB. Part of the emitted light enters the light receiving system 20 through the scanning mirror 31 in the laser radar device 100 as return light L2. The detailed structure of the light receiving system 20 will be described later.
- the rotation reflection unit 30 includes a scanning mirror 31 and a rotation drive unit 32.
- the scanning mirror 31 is a double-reflection polygon mirror, and includes a first reflecting portion 31a and a second reflecting portion 31b for bending an optical path.
- the first and second reflecting portions 31a and 31b are respectively arranged up and down along a rotation axis RX extending in parallel with the Z direction.
- the first and second reflecting portions 31a and 31b have a pyramid shape (specifically, see FIG. 2A and the like).
- the inclination angles of the reflecting surfaces of the first and second reflecting portions 31a and 31b gradually change with the rotation position of the scanning mirror 31 (in the illustrated example, the position facing four directions in units of 90 °).
- first and second reflecting portions 31a and 31b For the specific shapes of the first and second reflecting portions 31a and 31b, see International Publication No. 2014/168137). That is, in the scanning mirror 31, the mirror surfaces of the first and second reflecting portions 31a and 31b are inclined with respect to the Z-axis, and a plurality of combinations of the first and second reflecting portions 31a and 31b forming a pair are used. The crossing angles are different from each other. As a result, the scanning range in the ⁇ Z direction (sub scanning direction described later) parallel to the rotation axis RX is widened.
- the reflecting surface of the first reflecting portion 31a reflects the laser light (projected beam) L1 incident from the + X direction, which is the left direction on the paper surface, in a direction substantially orthogonal to the second reflecting portion 31b upward on the paper surface. Lead to the mirror surface.
- the mirror surface of the second reflecting portion 31b reflects the laser light L1 incident from the ⁇ Z direction, which is the downward direction on the paper surface, in a substantially orthogonal direction and guides it to the detection target OB side in the left direction on the paper surface.
- a part of the return light L2 reflected by the detection target OB follows a path opposite to the path of the laser light L1, and is detected by the light receiving system 20.
- the scanning mirror 31 reflects the return light L2 reflected by the detection target OB again by the mirror surface of the second reflection unit 31b and guides it to the mirror surface of the first reflection unit 31a. Subsequently, the return light L2 is reflected again by the mirror surface of the first reflecting portion 31a and guided to the light receiving system 20 side.
- the traveling direction of the laser light L1 changes in a plane orthogonal to the Z-axis direction (that is, the XY plane). That is, the laser beam L1 is scanned around the Z axis or along the Y axis direction as the scanning mirror 31 rotates.
- An angle area scanned by the laser beam L1 is a detection area.
- the range of the tilt angle with respect to the + X-axis direction which is the traveling direction of the projecting laser beam L1 is the projecting angle, and the traveling direction of the laser beam L1 at the scanning start point and the traveling direction of the laser beam L1 at the scanning end point. Is an irradiation angle.
- a projection visual field is formed by the projection angle and the irradiation angle.
- the direction in which the laser beam (projected beam) L1 scans (in this embodiment, the ⁇ Y direction perpendicular to the rotation axis RX) is the main scanning direction, the direction in which the laser beam (projected beam) L1 scans, and the laser beam.
- the direction orthogonal to the traveling direction of the (projection beam) L1 (in this embodiment, the ⁇ Z direction parallel to the rotation axis RX) is referred to as a sub-scanning direction.
- the center angle of the projection beam in the vertical direction or the Z direction of the projection field gradually changes according to the rotation position of the scanning mirror 31, and makes one rotation (360 °) of the scanning mirror 31.
- Sub-scan that moves, for example, in four stages with rotation) is achieved.
- the drive control unit 40 includes a light emission timing control unit 41 and a light reception timing control unit 42.
- the light emission timing control unit 41 controls operations of a plurality of light sources 11 a and 11 b described later in the light projecting system 10.
- the light emission timing control unit 41 has a drive circuit including a DSP, a power supply, and the like.
- the plurality of light sources 11a and 11b are driven and controlled to emit light at preset light emission timings.
- the light receiving timing control unit 42 controls the operation of the light receiving element 24 described later in the light receiving system 20.
- the light reception timing control unit 42 includes an interface circuit 45 including a plurality of switching units 43, a plurality of processing circuits 44, and the like.
- the former switching unit 43 is provided between the light receiving element 24 and the processing circuit 44. Thereby, since the number of parts is reduced and the parts are shared, the cost can be reduced. Further, the optical system 101 can be miniaturized by reducing the circuit scale.
- the switching unit 43 is connected so as to correspond to the plurality of pixels 24p (see FIG. 7) constituting the light detection surface 24a of the light receiving element 24, and the light detection areas DA1 and DA2 can be switched or selected. Yes. Specifically, as shown in FIG. 7, when the light receiving element 24 has six pixels 24 p and the light detection area is divided into two in the vertical direction of the drawing, that is, in the Z direction, three switching units 43 are provided across the vertical direction.
- the upper three pixels 24p and the lower three pixels 24p are switched at a predetermined light receiving timing.
- the light detected in the upper or lower light detection areas DA2 and DA1 (that is, the three pixels 24p) is subjected to signal processing by a processing circuit 44 provided on the output side of each switching unit 43.
- the processing circuit 44 includes a DSP and an A / D conversion unit, and performs signal processing of light detected by the light receiving element 24.
- the interface circuit 45 may be provided with an amplifier. In this case, the amplifier is provided between the light receiving element 24 and the switching unit 43, or between the switching unit 43 and the processing circuit 44, for example.
- the main control unit 50 controls the operations of the light sources 11a and 11b of the light projecting system 10 (see FIG. 2A and the like), the light receiving element 24 of the light receiving system 20 (see FIG. 2A and the like), the rotational drive unit 32 of the rotary reflecting unit 30, and the like. To do. Further, the main control unit 50 obtains the object information of the detection target OB from the electrical signal obtained by converting the return light L2 incident on the light receiving element 24 of the light receiving system 20. Specifically, when the output signal at the light receiving element 24 is equal to or greater than a predetermined threshold, the main control unit 50 determines that the light receiving element 24 has received the return light L2 from the detection target OB.
- the distance to the detection target OB is obtained from the difference between the light emission timings of the light sources 11a and 11b and the light reception timing of the light receiving element 24. Further, based on the light receiving position of the return light L2 to the light receiving element 24 in the sub-scanning direction and the rotation angle corresponding to the main scanning direction of the scanning mirror 31, object information such as the position, size, and shape of the detection target OB is obtained. Can be sought.
- the exterior component 60 is for covering and protecting the built-in component of the laser radar device 100.
- the exterior component 60 includes a lid-shaped main exterior portion 61 and a cylindrical container-shaped sub-exterior portion 62.
- the main exterior portion 61 and the sub exterior portion 62 are detachably fixed at their edges with fasteners such as bolts in a state in which confidentiality inside the exterior component 60 is maintained.
- the light projecting system 10 includes a plurality of light sources 11a and 11b and a plurality of collimator lenses that individually receive light SB1 and SB2 from the plurality of light sources 11a and 11b. 12a and 12b, and a mirror 13 for optical path synthesis.
- One light source 11a and one collimator lens 12a constitute a first light source element 14a
- the other light source 11b and the other collimator lens 12b constitute a second light source element 14b.
- a combination of the collimator lenses 12 a and 12 b and the optical path combining mirror 13 is a collimator unit 18.
- the second light source element 14b and the mirror 13 are arranged above the first light source element 14a, that is, at a position shifted in the + Z direction.
- the light emitting surface 16a of the first light source 11a and the light emitting surface 16b of the second light source 11b are longer in the direction corresponding to the sub-scanning direction than in the direction corresponding to the main scanning direction. That is, as conceptually shown in FIGS. 5A to 5C, the Z width which is the vertical dimension of the light emitting surface 16a of the first light source 11a is several times larger than the Y width which is the horizontal dimension of the light emitting surface 16a. Yes. Further, as conceptually shown in FIGS. 5D to 5F, the Z width which is the vertical dimension of the light emitting surface 16b of the second light source 11b is several times larger than the X width which is the horizontal dimension of the light emitting surface 16b. Yes.
- the light emitting surfaces 16a and 16b of the plurality of light sources 11a and 11b are longer in the direction corresponding to the sub-scanning direction than the direction corresponding to the main scanning direction, so that even a small number of light sources 11a and 11b are projected. It becomes easy to widen the visual field in the sub-scanning direction.
- the light source optical axis SX1 that is, the optical axis of the collimator lens 12a
- the light source optical axis SX2 that is, the optical axis of the collimator lens 12b
- the light source optical axis SX2 that is, the optical axis of the collimator lens 12b
- the light source optical axis SX2 which is the optical axis of the second light source element 14b
- the light source optical axis SX2 that is, the optical axis of the collimator lens 12b
- the light source optical axis SX2 that is, the optical axis of the collimator lens 12b
- It extends in parallel with the X axis in the downstream area A2 downstream of the optical path.
- the light source optical axis SX1 on the first light source 11a side is orthogonal to the preceding area A1 of the light source optical axis SX2 on the second light source 11b side, and both areas A1 and A2 are set in different angular directions. Yes. Further, the light source optical axis SX1 on the collimator lens 12a side and the rear region A2 of the light source optical axis SX2 on the collimator lens 12b side are arranged adjacent to each other in parallel, and the light sources 11a, 11a, It is about 11b wide.
- the plurality of light sources 11a and 11b are arranged at different positions in the Z direction corresponding to the sub-scanning direction, and appear to overlap with the same position in plan view on the rear side in the Y direction corresponding to the main scanning direction. Is arranged.
- the light emitting surface 16a of the first light source 11a is arranged so as to be biased in the ⁇ Z direction corresponding to the sub scanning direction from the vicinity of the light source optical axis SX1. That is, the center C1 of the light emitting surface 16a is deviated in the ⁇ Z direction, and is arranged off-axis in the ⁇ Z direction corresponding to the sub-scanning direction with respect to the collimator lens 12a constituting the collimator unit 18. . Further, as shown in FIGS.
- the light emitting surface 16b of the second light source 11b is arranged so as to be biased in the + Z direction corresponding to the sub-scanning direction from the vicinity of the light source optical axis SX2. That is, the center C2 of the light emitting surface 16b is deviated in the + Z direction, and is arranged off-axis with respect to the + Z direction corresponding to the sub-scanning direction with respect to the collimator lens 12b constituting the collimator unit 18.
- the emission optical axis AX1 of the light projecting system 10 is on the optical path from the light projecting system 10 to the scanning mirror 31, and the light source optical axis SX1 of the first light source element 14a and the first light axis SX1.
- the two light source elements 14b are arranged in the middle of the light source optical axis SX2 and the subsequent region A2.
- the first light source 11a and the second light source 11b are slightly displaced along the direction of the emission optical axis AX1, but with respect to the emission optical axis AX1. It can be said that they are arranged substantially symmetrically.
- the light SB1 emitted from the light emitting surface 16a of the light source 11a of the first light source element 14a exhibits a relatively wide divergence angle in the Y direction which is the horizontal direction and a relatively narrow divergence angle in the Z direction which is the vertical direction ( See FIGS. 5B and 5C).
- the divergence angle of the light SB1 is initially wide in the horizontal Y direction, but on the downstream side of the optical path of the first reflecting portion 31a (specifically, the light source 11a After a few hundred mm, that is, about 50 mm in front of the optical window 63), the aspect ratio of the aspect ratio becomes 1: 1, and then becomes wider in the vertical Z direction corresponding to the sub-scanning direction than in the horizontal Y direction.
- the light SB2 emitted from the light emitting surface 16b of the light source 11b of the second light source element 14b exhibits a relatively wide divergence angle in the X direction which is the horizontal direction and a relatively narrow divergence angle in the Z direction which is the vertical direction. (See FIGS. 5E and 5F).
- the divergence angle of the light SB2 is initially wide in the horizontal X direction, but the vertical and horizontal aspect ratio is 1: on the downstream side of the optical path of the first reflecting portion 31a. After that, it becomes wider in the vertical Z direction corresponding to the sub-scanning direction than in the horizontal Y direction.
- the light SB1 emitted from the light source 11a of the first light source element 14a disposed on the lower side is projected relatively lower in the distance through the scanning mirror 31, and the lower region is projected.
- the light SB2 that is illuminated and emitted from the light source 11b of the second light source element 14b disposed on the upper side in the sub-scanning direction is projected relatively upward in the distance through the scanning mirror 31 to illuminate the upper region.
- the light paths SB1 and SB2 from the pair of light sources 11a and 11b cross the optical axis AX1 with respect to the sub-scanning direction before and after entering the scanning mirror 31.
- the projected light SB1 and SB2 are subjected to upside down by the collimator unit 18 and upside down by the scanning mirror 31.
- the original vertical relationship is maintained as shown in FIG. 6A.
- the light projecting system 10 can be made relatively small in the sub-scanning direction. it can.
- the scanning areas AR1 and AR2 formed by the pair of light sources 11a and 11b form a locus in which the light SB1 and SB2 are moved in the Y direction, which is the main scanning direction. , And projected in the Y direction.
- the laser beam (projection beam) L1 composed of the light beams SB1 and SB2 extends in the Z direction or the sub-scanning direction on the object side to cover the range of projection angles.
- the laser light (projected beam) L1 composed of the light SB1 and SB2 moves in the Y direction or the main scanning direction within the range of the irradiation angle as the scanning mirror 31 rotates.
- the laser light (projection beam) L1 is emitted so that the positions of the projection fields of the light sources 11a and 11b in the sub-scanning direction are different, and the light sources 11a and 11b corresponding to the adjacent projection fields of the projection field are , Emit light at different timing (non-simultaneous light emission).
- the light receiving system 20 includes a perforated mirror 21, a light receiving lens 22, a mirror 23, and a light receiving element 24.
- the perforated mirror 21 is an optical path bending mirror disposed on the optical path between the scanning mirror 31 and the light receiving lens 22.
- the opening 21a of the perforated mirror 21 is formed at an appropriate position in the center of the perforated mirror 21 or in the vicinity thereof.
- the emission optical axis AX1 and the incident optical axis AX2 are disposed substantially coincident with each other in the section adjacent to the scanning mirror 31. That is, the exit optical axis AX1 and the incident optical axis AX2 of the light projecting system 10 pass through the approximate center of the opening 21a, and the light from the light sources 11a and 11b around the exit optical axis AX1 or the incident optical axis AX2 passing through the opening 21a.
- the lights SB1 and SB2 are narrowed in the upper and lower Z directions corresponding to the sub-scanning direction, and spread is suppressed by the collimator lenses 12a and 12b in the left and right Y directions corresponding to the main scanning direction. As a result, the light SB1 and SB2 pass through the opening 21a without waste.
- the size of the light projecting system 10 and the light receiving system 20 can be reduced in the sub-scanning direction, and the amount of received light can be increased.
- the return light L2 reflected by the first reflecting portion 31a through the second reflecting portion 31b of the scanning mirror 31 is reflected by the reflecting surface 21b of the perforated mirror (optical path folding mirror) 21 and bends the optical path in the orthogonal direction. It is done. At this time, a part of the return light L2 leaks out of the optical path through the opening 21a and is lost, but if the area ratio of the opening 21a to the first reflecting portion 31a is relatively small, the detection accuracy does not decrease.
- the light receiving lens 22 has a role of narrowing the beam diameter of the return light L2, and the mirror 23 has a role of guiding the return light L2 having passed through the light receiving lens 22 to the light receiving element 24.
- a band pass type filter 26 that blocks visible light other than the wavelength of the return light L2, that is, the laser light L1, is disposed.
- the light receiving lens 22 and the mirror 23 are arranged along the incident optical axis AX2.
- the light receiving element 24 detects the return light L2 that has passed through the light receiving lens 22 and the mirror 23.
- the light receiving element 24 is, for example, a CMOS, CCD, or other semiconductor device, and detects the intensity of the return light L2, and has position resolution in the vertical Z direction corresponding to the sub-scanning direction. That is, the light receiving element 24 has two or more pixels in the sub-scanning direction.
- the light receiving element 24 receives the return light L2 in the light detection areas DA1 and DA2 corresponding to the divided projection fields, and the adjacent light detection areas DA1 and DA2 receive the return light L2 at different timings (non-simultaneous light reception). ).
- the longitudinal direction of the light detection surface 24a is the sub-scanning direction.
- the light detection surface 24a includes six pixels 24p, and the six pixels 24p are arranged in the upper and lower Z directions corresponding to the sub-scanning direction. That is, the light detection surface 24a has a configuration of 6 pixels with respect to the Z direction corresponding to the sub-scanning direction and a configuration of 1 pixel with respect to the left and right Y directions corresponding to the main scanning direction.
- the light detection surface 24a of the light receiving element 24 has a width capable of capturing the return light L2 reflected in the reverse direction by the detection target OB within the projection angle range of the laser light L1 with respect to the vertical Z direction and the horizontal Y direction.
- the detection light L21 due to the light SB1 from the light source 11a and the detection light L22 due to the light SB2 from the light source 11b in the return light L2 are conceptually shown on the light detection surface 24a.
- the outline of the operation of the laser radar device 100 or the scanning optical system 101 will be described.
- the pair of light sources 11a and 11b of the light receiving system 20 are periodically caused to emit light under the control of the main control unit 50.
- the laser beam (projection beam) L1 synthesized by the meter unit 18 passes through the opening 21a of the perforated mirror (optical path bending mirror) 21 and passes through the scanning mirror 31, and the laser beam L1 that is long in the upper and lower sub-scanning directions is
- the main scanning is performed in the horizontal main scanning direction.
- the light sources 11a and 11b corresponding to the adjacent light projection fields emit light at different timings (specifically, the first light emission timing and the second light emission timing).
- the main control unit 50 operates the light emission timing control unit 41 to cause only the light source 11b to emit light among the plurality of 11a and 11b.
- the main control unit 50 operates the light reception timing control unit 42 to detect the detection light detected in the upper light detection area DA2 (that is, the three pixels 24p) by the switching unit 43 in the light receiving element 24 on the light receiving side.
- L22 is signal-processed by the processing circuit 44.
- the main control unit 50 operates the light emission timing control unit 41 to emit only the light source 11a among the plurality of 11a and 11b. .
- the main control unit 50 operates the light reception timing control unit 42, and in the light receiving element 24 on the light receiving side, detection detected in the lower light detection area DA1 (that is, the three pixels 24p) by the switching unit 43.
- the light L21 is signal-processed by the processing circuit 44. Therefore, as shown in the drawing, even if the return light L2 enters the upper light detection area DA2, light is not detected on the upper side.
- the laser light (projection beam) L1 from the plurality of light sources 11a and 11b is emitted so that the positions of the projection fields in the sub-scanning direction are different, and corresponds to the adjacent projection fields.
- the light sources 11a and 11b are caused to emit light at different timings.
- the relationship between the size of the light sources 11a and 11b and the focal length of the optical system 101 has a dominant influence on the beam diameter emitted from the light sources 11a and 11b.
- the energy density at a short distance decreases, it is possible to improve the eye safety.
- the spread of the beams from the light sources 11a and 11b and the focal length of the optical system 101 have a dominant influence on the beam diameter.
- the adjacent light projection fields do not overlap with each other, so that it is possible to satisfy the relatively safe Class 1 eye safe.
- the beam of the return light L2 protrudes slightly from the corresponding light detection areas DA1 and DA2. Even in this case, erroneous detection due to crosstalk can be prevented, and there is no need to increase the accuracy of alignment, thereby reducing the cost.
- light sources 11a and 11b each have a structure stacked in a direction corresponding to the main scanning direction (the horizontal direction in the drawing).
- the adjacent light sources 11a and 11b emit light at a timing at which the light emission timing of each layer of the stack structure is shifted.
- the width W of the light sources 11a and 11b is obtained by combining the width d1 of the light emission area of each stack element SC and the width d2 between the light emission areas by the number of stacks X.
- the total width (d1 + d2) of the width d1 and the width d2 is a spatial period of light projection. Further, the width W is adjusted so as to achieve a combined spatial period for each of the light sources 11a and 11b.
- each of the light sources 11a and 11b is composed of three stack elements SC.
- the upper and lower light sources 11a and 11b are displayed while being shifted in the horizontal direction, but are actually arranged spatially in the horizontal direction, and the horizontal direction is also generated in the projection space by causing a shift in the light emission timing. There is a gap.
- the light source 11a emitted at the second light emission timing is shifted by the time corresponding to the width d1 of the light emitting area with respect to the light source 11b emitted at the first light emission timing (light emission 1 in the drawing). I am letting.
- the light sources 11a and 11b repeat these light emission timings.
- the light source 11b emits light with respect to the light source 11a emitted at the immediately preceding second light emission timing (light emission 2 in the figure). The light is emitted while being shifted by a time corresponding to the width d1.
- the light source 11a corresponds to the width d1 of the light emission area with respect to the light source 11b emitted at the immediately preceding first light emission timing (light emission 3 in the figure). Turn on the light by shifting the time.
- the light emission period of the M light sources sequentially enables M lighting, and the light source is switched between the n-th rotation of the scanning mirror 31 and the n + 1-th rotation of the scanning mirror 31.
- the light emission timing is shifted by one pixel ⁇ P.
- the value M is a natural number of 2 or more
- the value n is a natural number of 1 or more.
- the arrangement of the light sources LD1, LD2, and LD3 shown in FIG. 10A is a virtual arrangement that eliminates the bending of the optical path and the like for convenience of explanation.
- FIGS. 11A, 11B, and 11C show the projection state or projection field of the first rotation, the second rotation, and the third rotation, respectively, as an example. As described above, in the case of the scanning mirror 31 shown in FIG.
- FIGS. 11A to 11C show the projected field of view during the one-stage scanning. Some specific planes QA are shown.
- the upper part of each figure shows a projection pattern P1 composed of an image Q1 of the light source LD1
- the middle part shows a projection pattern P2 composed of an image Q2 of the light source LD2
- the lower part shows a projection pattern P2 composed of an image Q3 of the light source LD3.
- the light emission period T of the three light sources LD1, LD2, and LD3 sequentially enables three lighting (intervals corresponding to individual light emission periods or spatial periods T1 to T3 (the light emission period T).
- the light sources LD1, LD2, and LD3 have intervals or spatial periods corresponding to the light emission period.
- the light emission timings of T1 to T3 are shifted by T / 3 corresponding to one pixel ⁇ P.
- the laser radar device 100 is also operated at the same light emission timing after the fourth rotation. Note that the spatial period obtained by integrating the light projections for three rotations of the scanning mirror 31 is T / 3.
- the scanning optical system according to the fourth embodiment is a partial modification of the scanning optical system according to the first embodiment, and the matters not specifically described are the same as those of the first embodiment. It is.
- the light projecting system 10 and the light receiving system 20 are simply separated, and the light projecting system 10 and the light receiving system 20 are related to the sub-scanning direction or the Z direction. They are located at different positions. That is, the emission optical axis AX1 and the incident optical axis AX2 of the light projecting system 10 are arranged adjacent to each other in parallel in the section between the mirror 23 and the scanning mirror 31, and are in the Z direction or the sub scanning direction. Are separated.
- the exit optical axis AX1 and the incident optical axis AX2 are arranged at different positions in the Z direction corresponding to the sub-scanning direction, and the Y direction corresponding to the main scanning direction. Are arranged so as to overlap each other in plan view.
- the light projecting system 10 and the light receiving system 20 are simply separated.
- the light receiving system 20 includes a light receiving lens 22, a mirror 23, and a light receiving element 24.
- a perforated mirror is unnecessary.
- the light detection surface 24a of the light receiving element 24 extends in the X direction due to the optical path bending by the mirror 23, but the X direction corresponds to the sub-scanning direction.
- the first light source element 14a and the second light source element 14b are mirror images arranged in the vertical sub-scanning direction across the emission optical axis AX1.
- the first light source 11a and the second light source 11b are disposed strictly symmetrically with respect to the emission optical axis AX1.
- a combination of the pair of collimator lenses 12a and 12b is a collimator unit 18, and a mirror for synthesizing the optical path is not necessary.
- the light source 11a is arranged off-axis so as to be asymmetric in the sub-scanning direction with respect to the collimator lens 12a constituting the collimator unit 18, and the first light source element 14b.
- the light source 11b is arranged off-axis so as to be asymmetric in the sub-scanning direction with respect to the collimator lens 12b constituting the collimator unit 18.
- the light receiving system 20 is the same as that shown in the first embodiment, but the light receiving system 20 is the same as that shown in the fourth embodiment. It is also possible to completely separate the optical path.
- the laser radar device 100 includes a light projecting system 10, a light receiving system 20, a rotary reflection unit 30, a main control unit 50, and an exterior component 60, as in the first embodiment.
- the scanning mirror 31 of the rotary reflection unit 30 of this embodiment is a one-time reflection type polygon mirror, and includes only the first reflection unit 31a for bending the optical path.
- the mirror surface of the first reflecting portion 31 a is inclined with respect to the Z axis, and reflects the laser beam L 1 incident from the ⁇ Z direction, which is the downward direction on the paper surface, in a direction substantially orthogonal to the scanning mirror 31. It is guided to the left side to be detected OB on the paper surface.
- a part of the return light L2 reflected by the detection target OB follows a path opposite to the path of the laser light L1, and is detected by the light receiving system 20.
- the left and right X directions perpendicular to the rotation axis RX of the scanning mirror 31 are sub-scanning directions
- the Y direction perpendicular to the rotation axis RX is the main scanning direction. It has become.
- the number of pixels 24p constituting the light detection surface 24a of the light receiving element 24 is not limited to six, and can be an appropriate number according to the detection resolution.
- optical elements constituting the light projecting system 10 and the light receiving system 20 are not limited to those illustrated in FIG. 2A and the like, and by increasing the number of mirrors for bending the optical path, increasing the number of lenses, etc. Various changes are possible.
- the light receiving element 24 receives the return light L2 at different timings in the adjacent light detection areas DA1 and DA2, but the light detection corresponding to the light projection field divided by the return light L2 by a filter or the like.
- the return light L2 may be received at the same timing as long as it is limited to be incident on the areas DA1 and DA2 almost accurately.
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Abstract
A scanning optical system 101 is equipped with: a light projection system 10 which is provided with a plurality of light sources 11a, 11b and a collimator unit 18 into which light from each of the light sources 11a, 11b is made to enter; a scanning mirror 31 which reflects the light from the light projection system 10 as a laser beam L1 to serve as a projection beam, and scans the laser beam in a main scanning direction; a light receiving lens 22 upon which returning light L2 from the scanning mirror 31 is incident; and a light receiving element 24 upon which returning light L2 that has passed through the light receiving lens 22 is incident. The plurality of light sources 11a, 11b are disposed in positions that differ in a direction corresponding to an auxiliary scanning direction, which is orthogonal to the main scanning direction. The light receiving element 24 is disposed so as to be capable of detecting returning light L2 corresponding to the plurality of light sources 11a, 11b and is provided with at least two pixels in a direction corresponding to the auxiliary scanning direction. The laser beam L1 is emitted such that the positions in the auxiliary scanning direction of the light projection fields from the light sources 11a, 11b are different. The light sources 11a, 11b corresponding to adjacent light projection fields from among the light projection fields emit light at different timings.
Description
本発明は、投光ビームを走査しつつ対象物からの戻り光を検出するための走査型の光学系及びこれを組み込んだレーザーレーダー装置に関する。
The present invention relates to a scanning optical system for detecting return light from an object while scanning a projection beam, and a laser radar apparatus incorporating the scanning optical system.
レーザー光を2次元的に走査しつつ照射し、走査範囲内に存在する物体から戻ってきた反射光を検出することで、物体までの距離を検出する距離測定装置が公知となっている(例えば、特許文献1参照)。特許文献1に記載の距離測定装置では、複数の光源からのレーザー出力を一点に集めてハイパワーを得ている。
2. Description of the Related Art A distance measuring device that detects a distance to an object by irradiating laser light while scanning in two dimensions and detecting reflected light returned from an object existing within the scanning range is known (for example, , See Patent Document 1). In the distance measuring device described in Patent Document 1, high power is obtained by collecting laser outputs from a plurality of light sources at one point.
しかしながら、特許文献1の装置では、光源の発光タイミングが不明であり、また、複数の光源が直列に接続されているため、各光源が同時に発光することしかできない。そのため、各光源に対応する投光視野に重複する部分があると、当該重複部分のエネルギー密度が高くなりClass1のアイセーフを満たさなくなるという問題が生じうる。なお、戻り光を受光素子全体で同時に受光すると、戻り光のビームが対応する光検出領域からはみ出して入射した場合、クロストークにより受光素子の隣接する光検出領域で誤検知が生じうる。
However, in the apparatus of Patent Document 1, the light emission timing of the light source is unknown, and since a plurality of light sources are connected in series, each light source can only emit light simultaneously. For this reason, if there is an overlapping portion in the projection visual field corresponding to each light source, the energy density of the overlapping portion becomes high, which may cause a problem that the eye safe of Class 1 is not satisfied. When the return light is simultaneously received by the entire light receiving element, if the return light beam protrudes from the corresponding light detection area and enters the light detection area, erroneous detection may occur in the light detection area adjacent to the light receiving element due to crosstalk.
本発明は、上記背景技術の問題点に鑑みてなされたものであり、アイセーフ等に関する問題を解決しつつ、遠距離での検知も可能な走査型の光学系及びレーザーレーダー装置を提供することを目的とする。
The present invention has been made in view of the above-mentioned problems of the background art, and provides a scanning optical system and a laser radar device that can detect at a long distance while solving problems relating to eye-safety and the like. Objective.
上記した目的のうち少なくとも一つを実現するために、本発明の一側面を反映した走査型の光学系は、複数の光源と、光源からの光をそれぞれ入射させるコリメーター部とを有する投光系と、投光系からの光を投光ビームとして反射し、主走査方向に走査させる走査用ミラーと、走査用ミラーからの戻り光が入射する受光レンズと、受光レンズを経た戻り光が入射する受光素子と、を備え、複数の光源は、主走査方向に直交する副走査方向に対応する方向に異なる位置に配置され、受光素子は、複数の光源に対応する戻り光を検出可能に配置され、副走査方向に対応する方向に2画素以上を有し、投光ビームは、各光源による投光視野の副走査方向の位置が異なるように出射され、投光視野のうち隣接する投光視野に対応する光源は、異なるタイミングで発光する。ここで、投光視野とは、光源から出射されるビームの走査領域上の範囲であり、複数の光源が発光する場合、各光源に対応するビームの範囲をひとまとまりの投光視野としている。
In order to achieve at least one of the above objects, a scanning optical system reflecting one aspect of the present invention includes a plurality of light sources and a collimator unit that each receives light from the light sources. System, a scanning mirror that reflects the light from the light projecting system as a light projection beam and scans in the main scanning direction, a light receiving lens to which the return light from the scanning mirror is incident, and a return light that has passed through the light receiving lens is incident A plurality of light sources arranged at different positions in a direction corresponding to the sub-scanning direction orthogonal to the main scanning direction, and the light receiving elements arranged to detect return light corresponding to the plurality of light sources. And having two or more pixels in the direction corresponding to the sub-scanning direction, and the light projecting beams are emitted so that the positions of the light projecting fields of the light sources in the sub-scanning direction are different from each other. The light source corresponding to the field of view is different. It emits light at the timing. Here, the light projection field is a range on the scanning region of the beam emitted from the light source. When a plurality of light sources emit light, the range of the beam corresponding to each light source is defined as a group of light projection fields.
上記した目的のうち少なくとも一つを実現するために、本発明の一側面を反映したレーザーレーダー装置は、上述した走査型の光学系を備え、戻り光に基づいて対象物を検出する。
In order to achieve at least one of the above objects, a laser radar device reflecting one aspect of the present invention includes the above-described scanning optical system and detects an object based on return light.
〔第1実施形態〕
以下、図1等を参照しつつ、第1実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。 [First Embodiment]
Hereinafter, the scanning optical system according to the first embodiment and a laser radar device incorporating the same will be described with reference to FIG. 1 and the like.
以下、図1等を参照しつつ、第1実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。 [First Embodiment]
Hereinafter, the scanning optical system according to the first embodiment and a laser radar device incorporating the same will be described with reference to FIG. 1 and the like.
図1に示すレーザーレーダー装置100は、例えば屋内外監視用途や車載用途の物体検出装置であり、検出対象の存在や当該検出対象までの距離を検出する。レーザーレーダー装置100は、投光系10と、受光系20と、回転反射部30と、駆動制御部40と、主制御部50と、外装部品60とを備える。これらのうち、投光系10と、受光系20と、回転反射部30とは、走査型の光学系101を構成している。
A laser radar device 100 shown in FIG. 1 is an object detection device for indoor / outdoor monitoring or in-vehicle use, for example, and detects the presence of a detection target and the distance to the detection target. The laser radar device 100 includes a light projecting system 10, a light receiving system 20, a rotary reflection unit 30, a drive control unit 40, a main control unit 50, and an exterior component 60. Among these, the light projecting system 10, the light receiving system 20, and the rotary reflection unit 30 constitute a scanning optical system 101.
レーザーレーダー装置100又は走査型の光学系101のうち、投光系10は、後述する回転反射部30の走査用ミラー31に対して投光ビームの元になるレーザー光L1を投射する。投光系10の詳細な構造については後述する。
Of the laser radar device 100 or the scanning optical system 101, the light projecting system 10 projects the laser light L1 that is the source of the light projecting beam onto the scanning mirror 31 of the rotary reflector 30 described later. The detailed structure of the light projecting system 10 will be described later.
受光系20は、外装部品60の光学窓63を介して入射する検出対象OBからの反射光すなわち戻り光L2であって、回転反射部30の走査用ミラー31で反射された戻り光L2を受光する。より詳細には、検出領域内に物体等の検出対象OBがあると、レーザーレーダー装置100から射出されたレーザー光(投光ビーム)L1が検出対象OBで反射等され、検出対象OBで反射等された光の一部が戻り光L2としてレーザーレーダー装置100における走査用ミラー31を介して受光系20に入射する。受光系20の詳細な構造については後述する。
The light receiving system 20 receives the return light L2 reflected from the detection target OB incident through the optical window 63 of the exterior component 60, that is, the return light L2, and reflected by the scanning mirror 31 of the rotary reflection unit 30. To do. More specifically, when there is a detection target OB such as an object in the detection region, the laser light (projection beam) L1 emitted from the laser radar device 100 is reflected by the detection target OB and reflected by the detection target OB. Part of the emitted light enters the light receiving system 20 through the scanning mirror 31 in the laser radar device 100 as return light L2. The detailed structure of the light receiving system 20 will be described later.
回転反射部30は、走査用ミラー31と回転駆動部32とを有する。走査用ミラー31は、2回反射型のポリゴンミラーであり、光路折り曲げ用の第1反射部31aと第2反射部31bとを有する。第1及び第2反射部31a,31bは、Z方向に平行に延びる回転軸RXに沿って上下にそれぞれ配置されている。第1及び第2反射部31a,31bは角錐状の形状を有している(具体的には図2A等参照)。第1及び第2反射部31a,31bの反射面の傾斜角は、走査用ミラー31の回転位置(図示の例では90°単位で4方位を向く位置)に伴って徐々に変化するものになっている(第1及び第2反射部31a,31bの具体的な形状については、国際公開第2014/168137号参照)。つまり、走査用ミラー31において、第1及び第2反射部31a,31bの鏡面は、Z軸に対してそれぞれ傾斜しており、対となる第1及び第2反射部31a,31bの複数の組み合わせにおいて、それぞれ交差角が異なるものとなっている。これにより、回転軸RXに平行な±Z方向(後述する副走査方向)の走査範囲が広くなる。第1反射部31aの反射面は、紙面上で左方向である+X方向から入射したレーザー光(投光ビーム)L1を略直交する方向に反射し、紙面上で上方向の第2反射部31bの鏡面に導く。第2反射部31bの鏡面は、紙面上で下方向である-Z方向から入射したレーザー光L1を略直交する方向に反射し、紙面上で左方向の検出対象OB側へ導く。検出対象OBで反射された一部の戻り光L2は、レーザー光L1の経路と逆の経路をたどり、受光系20で検出される。つまり、走査用ミラー31は、検出対象OBで反射された戻り光L2を、第2反射部31bの鏡面で再度反射させ、第1反射部31aの鏡面に導く。続いて、戻り光L2を第1反射部31aの鏡面で再度反射させ、受光系20側へ導く。走査用ミラー31が回転すると、Z軸方向に直交する平面(つまり、XY面)内において、レーザー光L1の進行方向が変化する。つまり、レーザー光L1は、走査用ミラー31の回転に伴って、Z軸のまわりに又はY軸方向に沿って走査される。レーザー光L1によって走査される角度領域が検出領域となる。投光用のレーザー光L1の進行方向である+X軸方向に対する傾斜角の範囲が投光角度であり、走査開始点でのレーザー光L1の進行方向と走査終了点でのレーザー光L1の進行方向とのなす角度が照射角度であるとする。投光角度と照射角度とによって投光視野が形成される。以上において、レーザー光(投光ビーム)L1が走査する方向(本実施形態では回転軸RXに垂直な±Y方向)を主走査方向、レーザー光(投光ビーム)L1が走査する方向及びレーザー光(投光ビーム)L1の進行方向に直交する方向(本実施形態では回転軸RXに平行な±Z方向)を副走査方向と呼ぶ。なお、投光視野の縦方向又はZ方向に関する投光ビームの中心角度は、上述のように、走査用ミラー31の回転位置に応じて徐々に変化し、走査用ミラー31の1回転(360°回転)に伴って例えば4段階移動する副走査が達成される。
The rotation reflection unit 30 includes a scanning mirror 31 and a rotation drive unit 32. The scanning mirror 31 is a double-reflection polygon mirror, and includes a first reflecting portion 31a and a second reflecting portion 31b for bending an optical path. The first and second reflecting portions 31a and 31b are respectively arranged up and down along a rotation axis RX extending in parallel with the Z direction. The first and second reflecting portions 31a and 31b have a pyramid shape (specifically, see FIG. 2A and the like). The inclination angles of the reflecting surfaces of the first and second reflecting portions 31a and 31b gradually change with the rotation position of the scanning mirror 31 (in the illustrated example, the position facing four directions in units of 90 °). (For the specific shapes of the first and second reflecting portions 31a and 31b, see International Publication No. 2014/168137). That is, in the scanning mirror 31, the mirror surfaces of the first and second reflecting portions 31a and 31b are inclined with respect to the Z-axis, and a plurality of combinations of the first and second reflecting portions 31a and 31b forming a pair are used. The crossing angles are different from each other. As a result, the scanning range in the ± Z direction (sub scanning direction described later) parallel to the rotation axis RX is widened. The reflecting surface of the first reflecting portion 31a reflects the laser light (projected beam) L1 incident from the + X direction, which is the left direction on the paper surface, in a direction substantially orthogonal to the second reflecting portion 31b upward on the paper surface. Lead to the mirror surface. The mirror surface of the second reflecting portion 31b reflects the laser light L1 incident from the −Z direction, which is the downward direction on the paper surface, in a substantially orthogonal direction and guides it to the detection target OB side in the left direction on the paper surface. A part of the return light L2 reflected by the detection target OB follows a path opposite to the path of the laser light L1, and is detected by the light receiving system 20. In other words, the scanning mirror 31 reflects the return light L2 reflected by the detection target OB again by the mirror surface of the second reflection unit 31b and guides it to the mirror surface of the first reflection unit 31a. Subsequently, the return light L2 is reflected again by the mirror surface of the first reflecting portion 31a and guided to the light receiving system 20 side. When the scanning mirror 31 rotates, the traveling direction of the laser light L1 changes in a plane orthogonal to the Z-axis direction (that is, the XY plane). That is, the laser beam L1 is scanned around the Z axis or along the Y axis direction as the scanning mirror 31 rotates. An angle area scanned by the laser beam L1 is a detection area. The range of the tilt angle with respect to the + X-axis direction, which is the traveling direction of the projecting laser beam L1, is the projecting angle, and the traveling direction of the laser beam L1 at the scanning start point and the traveling direction of the laser beam L1 at the scanning end point. Is an irradiation angle. A projection visual field is formed by the projection angle and the irradiation angle. In the above, the direction in which the laser beam (projected beam) L1 scans (in this embodiment, the ± Y direction perpendicular to the rotation axis RX) is the main scanning direction, the direction in which the laser beam (projected beam) L1 scans, and the laser beam. The direction orthogonal to the traveling direction of the (projection beam) L1 (in this embodiment, the ± Z direction parallel to the rotation axis RX) is referred to as a sub-scanning direction. As described above, the center angle of the projection beam in the vertical direction or the Z direction of the projection field gradually changes according to the rotation position of the scanning mirror 31, and makes one rotation (360 °) of the scanning mirror 31. Sub-scan that moves, for example, in four stages with rotation) is achieved.
駆動制御部40は、発光タイミング制御部41と、受光タイミング制御部42とを有する。発光タイミング制御部41は、投光系10のうち後述する複数の光源11a,11bの動作を制御する。発光タイミング制御部41は、DSPや電源等を含む駆動回路を有する。複数の光源11a,11bは、予め設定された発光タイミングによって発光するように駆動制御される。受光タイミング制御部42は、受光系20のうち後述する受光素子24の動作を制御する。図3に示すように、受光タイミング制御部42は、複数のスイッチング部43や複数の処理回路44等を含むインターフェース回路45を有する。前者のスイッチング部43は、受光素子24と処理回路44との間に設けられている。これにより、部品点数を削減及び部品を共通化するため、コストダウンを図ることができる。また、回路規模を縮小することにより光学系101を小型化することができる。スイッチング部43は、受光素子24の光検出面24aを構成する複数の画素24p(図7参照)に対応するように接続されており、光検出領域DA1,DA2の切り替え又は選択が可能となっている。具体的には、図7に示すように、受光素子24が6つの画素24pを有し光検出領域を図面の上下すなわちZ方向に2分割する場合、上下に跨る3つのスイッチング部43が設けられており、上側の3つの画素24pと下側の3つの画素24pとが所定の受光タイミングで切り替わるようになっている。上側又は下側の光検出領域DA2,DA1(つまり、3つの画素24p)で検出された光は、各スイッチング部43の出力側に設けた処理回路44で信号処理される。処理回路44は、DSPやA/D変換部を含み、受光素子24で検出される光の信号処理を行う。なお、インターフェース回路45には、アンプが設けられてもよく、この場合、アンプは例えば受光素子24とスイッチング部43との間や、スイッチング部43と処理回路44との間に設けられる。
The drive control unit 40 includes a light emission timing control unit 41 and a light reception timing control unit 42. The light emission timing control unit 41 controls operations of a plurality of light sources 11 a and 11 b described later in the light projecting system 10. The light emission timing control unit 41 has a drive circuit including a DSP, a power supply, and the like. The plurality of light sources 11a and 11b are driven and controlled to emit light at preset light emission timings. The light receiving timing control unit 42 controls the operation of the light receiving element 24 described later in the light receiving system 20. As illustrated in FIG. 3, the light reception timing control unit 42 includes an interface circuit 45 including a plurality of switching units 43, a plurality of processing circuits 44, and the like. The former switching unit 43 is provided between the light receiving element 24 and the processing circuit 44. Thereby, since the number of parts is reduced and the parts are shared, the cost can be reduced. Further, the optical system 101 can be miniaturized by reducing the circuit scale. The switching unit 43 is connected so as to correspond to the plurality of pixels 24p (see FIG. 7) constituting the light detection surface 24a of the light receiving element 24, and the light detection areas DA1 and DA2 can be switched or selected. Yes. Specifically, as shown in FIG. 7, when the light receiving element 24 has six pixels 24 p and the light detection area is divided into two in the vertical direction of the drawing, that is, in the Z direction, three switching units 43 are provided across the vertical direction. The upper three pixels 24p and the lower three pixels 24p are switched at a predetermined light receiving timing. The light detected in the upper or lower light detection areas DA2 and DA1 (that is, the three pixels 24p) is subjected to signal processing by a processing circuit 44 provided on the output side of each switching unit 43. The processing circuit 44 includes a DSP and an A / D conversion unit, and performs signal processing of light detected by the light receiving element 24. The interface circuit 45 may be provided with an amplifier. In this case, the amplifier is provided between the light receiving element 24 and the switching unit 43, or between the switching unit 43 and the processing circuit 44, for example.
主制御部50は、投光系10の光源11a,11b(図2A等参照)、受光系20の受光素子24(図2A等参照)、回転反射部30の回転駆動部32等の動作を制御する。また、主制御部50は、受光系20の受光素子24に入射した戻り光L2の変換によって得た電気信号から検出対象OBの物体情報を得る。具体的には、受光素子24における出力信号が所定の閾値以上である場合、主制御部50において、受光素子24が検出対象OBからの戻り光L2を受光したと判断される。この場合、光源11a,11bでの発光タイミングと受光素子24での受光タイミングとの差から、検出対象OBまでの距離が求められる。また、受光素子24への戻り光L2の副走査方向に関する受光位置及び走査用ミラー31の主走査方向に相当する回転角に基づいて、検出対象OBの位置、大きさ、形状等の物体情報を求めることができる。
The main control unit 50 controls the operations of the light sources 11a and 11b of the light projecting system 10 (see FIG. 2A and the like), the light receiving element 24 of the light receiving system 20 (see FIG. 2A and the like), the rotational drive unit 32 of the rotary reflecting unit 30, and the like. To do. Further, the main control unit 50 obtains the object information of the detection target OB from the electrical signal obtained by converting the return light L2 incident on the light receiving element 24 of the light receiving system 20. Specifically, when the output signal at the light receiving element 24 is equal to or greater than a predetermined threshold, the main control unit 50 determines that the light receiving element 24 has received the return light L2 from the detection target OB. In this case, the distance to the detection target OB is obtained from the difference between the light emission timings of the light sources 11a and 11b and the light reception timing of the light receiving element 24. Further, based on the light receiving position of the return light L2 to the light receiving element 24 in the sub-scanning direction and the rotation angle corresponding to the main scanning direction of the scanning mirror 31, object information such as the position, size, and shape of the detection target OB is obtained. Can be sought.
外装部品60は、レーザーレーダー装置100の内蔵部品を覆い、保護するためのものである。外装部品60は、蓋状の主外装部61と、円筒容器状の副外装部62とを有する。主外装部61と副外装部62とは、これらの縁部において、外装部品60の内部の機密性を保った状態でボルト等の留め具で着脱可能に固定されている。
The exterior component 60 is for covering and protecting the built-in component of the laser radar device 100. The exterior component 60 includes a lid-shaped main exterior portion 61 and a cylindrical container-shaped sub-exterior portion 62. The main exterior portion 61 and the sub exterior portion 62 are detachably fixed at their edges with fasteners such as bolts in a state in which confidentiality inside the exterior component 60 is maintained.
図2A及び2B又は図4A及び4Bに示すように、投光系10は、複数の光源11a,11bと、複数の光源11a,11bからの光SB1,SB2を個別に入射させる複数のコリメーターレンズ12a,12bと、光路合成用のミラー13とを有する。一方の光源11aと一方のコリメーターレンズ12aとによって第1光源要素14aが構成され、他方の光源11bと他方のコリメーターレンズ12bとによって第2光源要素14bが構成される。また、コリメーターレンズ12a,12bと光路合成用のミラー13とを合わせたものがコリメーター部18となっている。第2光源要素14b及びミラー13は、第1光源要素14aよりも上側すなわち+Z方向にシフトした位置に配置されている。
As shown in FIGS. 2A and 2B or FIGS. 4A and 4B, the light projecting system 10 includes a plurality of light sources 11a and 11b and a plurality of collimator lenses that individually receive light SB1 and SB2 from the plurality of light sources 11a and 11b. 12a and 12b, and a mirror 13 for optical path synthesis. One light source 11a and one collimator lens 12a constitute a first light source element 14a, and the other light source 11b and the other collimator lens 12b constitute a second light source element 14b. Further, a combination of the collimator lenses 12 a and 12 b and the optical path combining mirror 13 is a collimator unit 18. The second light source element 14b and the mirror 13 are arranged above the first light source element 14a, that is, at a position shifted in the + Z direction.
第1の光源の11aの発光面16a並びに第2の光源11bの発光面16bは、主走査方向に対応する方向よりも副走査方向に対応する方向に長い。すなわち、図5A~5Cに概念的に示すように、第1の光源11aの発光面16aの縦寸法であるZ幅は、発光面16aの横寸法であるY幅よりも数倍以上大きくなっている。また、図5D~5Fに概念的に示すように、第2の光源11bの発光面16bの縦寸法であるZ幅は、発光面16bの横寸法であるX幅よりも数倍以上大きくなっている。以上のように、複数の光源11a,11bの発光面16a,16bが主走査方向に対応する方向よりも副走査方向に対応する方向に長いことにより、少ない光源11a,11bであっても投光視野を副走査方向に広くすることが容易になる。
The light emitting surface 16a of the first light source 11a and the light emitting surface 16b of the second light source 11b are longer in the direction corresponding to the sub-scanning direction than in the direction corresponding to the main scanning direction. That is, as conceptually shown in FIGS. 5A to 5C, the Z width which is the vertical dimension of the light emitting surface 16a of the first light source 11a is several times larger than the Y width which is the horizontal dimension of the light emitting surface 16a. Yes. Further, as conceptually shown in FIGS. 5D to 5F, the Z width which is the vertical dimension of the light emitting surface 16b of the second light source 11b is several times larger than the X width which is the horizontal dimension of the light emitting surface 16b. Yes. As described above, the light emitting surfaces 16a and 16b of the plurality of light sources 11a and 11b are longer in the direction corresponding to the sub-scanning direction than the direction corresponding to the main scanning direction, so that even a small number of light sources 11a and 11b are projected. It becomes easy to widen the visual field in the sub-scanning direction.
図4A及び4Bに戻って、第1光源要素14aの光軸である光源光軸SX1(すなわち、コリメーターレンズ12aの光軸)は、X軸に平行に延びている。一方、第2光源要素14bの光軸である光源光軸SX2(すなわちコリメーターレンズ12bの光軸)は、ミラー13よりも光路上流の前段領域A1でY軸に平行に延び、ミラー13よりも光路下流の後段領域A2でX軸に平行に延びている。つまり、第1の光源11a側における光源光軸SX1は、第2の光源11b側における光源光軸SX2の前段領域A1と直交しており、両領域A1,A2は、異なる角度方向に設定されている。さらに、コリメーターレンズ12a側における光源光軸SX1とコリメーターレンズ12b側における光源光軸SX2の後段領域A2とは互いに平行に隣接して配置されており、Z方向又は副走査方向に光源11a,11bの幅程度離間している。つまり、複数の光源11a,11bは、副走査方向に対応するZ方向に異なる位置に配置されており、主走査方向に対応するY方向には後段側で平面視で同じ位置に重なって見えるように配置されている。
4A and 4B, the light source optical axis SX1 (that is, the optical axis of the collimator lens 12a) that is the optical axis of the first light source element 14a extends in parallel to the X axis. On the other hand, the light source optical axis SX2 (that is, the optical axis of the collimator lens 12b), which is the optical axis of the second light source element 14b, extends in parallel to the Y axis in the upstream region A1 upstream of the mirror 13 and further than the mirror 13. It extends in parallel with the X axis in the downstream area A2 downstream of the optical path. That is, the light source optical axis SX1 on the first light source 11a side is orthogonal to the preceding area A1 of the light source optical axis SX2 on the second light source 11b side, and both areas A1 and A2 are set in different angular directions. Yes. Further, the light source optical axis SX1 on the collimator lens 12a side and the rear region A2 of the light source optical axis SX2 on the collimator lens 12b side are arranged adjacent to each other in parallel, and the light sources 11a, 11a, It is about 11b wide. That is, the plurality of light sources 11a and 11b are arranged at different positions in the Z direction corresponding to the sub-scanning direction, and appear to overlap with the same position in plan view on the rear side in the Y direction corresponding to the main scanning direction. Is arranged.
図5A~5C等に示すように、第1の光源11aの発光面16aは、光源光軸SX1の近傍から副走査方向に対応する-Z方向に偏って配置されている。つまり、発光面16aの中心C1は、-Z方向に偏っており、コリメーター部18を構成するコリメーターレンズ12aに対して副走査方向に対応する-Z方向に関して軸外し状態で配置されている。また、図5D~5F等に示すように、第2の光源11bの発光面16bは、光源光軸SX2の近傍から副走査方向に対応する+Z方向に偏って配置されている。つまり、発光面16bの中心C2は、+Z方向に偏っており、コリメーター部18を構成するコリメーターレンズ12bに対して副走査方向に対応する+Z方向に関して軸外し状態で配置されている。
As shown in FIGS. 5A to 5C and the like, the light emitting surface 16a of the first light source 11a is arranged so as to be biased in the −Z direction corresponding to the sub scanning direction from the vicinity of the light source optical axis SX1. That is, the center C1 of the light emitting surface 16a is deviated in the −Z direction, and is arranged off-axis in the −Z direction corresponding to the sub-scanning direction with respect to the collimator lens 12a constituting the collimator unit 18. . Further, as shown in FIGS. 5D to 5F and the like, the light emitting surface 16b of the second light source 11b is arranged so as to be biased in the + Z direction corresponding to the sub-scanning direction from the vicinity of the light source optical axis SX2. That is, the center C2 of the light emitting surface 16b is deviated in the + Z direction, and is arranged off-axis with respect to the + Z direction corresponding to the sub-scanning direction with respect to the collimator lens 12b constituting the collimator unit 18.
図4A及び4B等に示すように、投光系10の射出光軸AX1は、投光系10から走査用ミラー31に向かう光路上にあって、第1光源要素14aの光源光軸SX1と第2光源要素14bの光源光軸SX2の後段領域A2との中間に配置されている。ミラー13による光路の折り曲げがないとして光路を展開すると、第1の光源11aと第2の光源11bとは、射出光軸AX1の方向に沿って若干のずれはあるが射出光軸AX1に対して概ね対称的に配置されているということができる。第1光源要素14aの光源11aの発光面16aから射出された光SB1は、横方向であるY方向に比較的広い発散角を示し、縦方向であるZ方向に比較的狭い発散角を示す(図5B及び5C参照)。一方で、光源11aの発光面16aが縦方向に長いことから、光SB1の拡がり角は、当初横のY方向に広いものの、第1反射部31aの光路下流側(具体的には、光源11aから数100mm後、すなわち光学窓63の前方50mm程度)で縦横のアスペクト比が1:1となり、その後、横のY方向よりも副走査方向に対応する縦のZ方向に広くなる。同様に、第2光源要素14bの光源11bの発光面16bから射出された光SB2は、横方向であるX方向に比較的広い発散角を示し、縦方向であるZ方向に比較的狭い発散角を示す(図5E及び5F参照)。一方で、光源11bの発光面16bが縦方向に長いことから、光SB2の拡がり角は、当初横のX方向に広いものの、第1反射部31aの光路下流側で縦横のアスペクト比が1:1となり、その後、横のY方向よりも副走査方向に対応する縦のZ方向に広くなる。
As shown in FIGS. 4A and 4B, the emission optical axis AX1 of the light projecting system 10 is on the optical path from the light projecting system 10 to the scanning mirror 31, and the light source optical axis SX1 of the first light source element 14a and the first light axis SX1. The two light source elements 14b are arranged in the middle of the light source optical axis SX2 and the subsequent region A2. When the optical path is developed assuming that the optical path is not bent by the mirror 13, the first light source 11a and the second light source 11b are slightly displaced along the direction of the emission optical axis AX1, but with respect to the emission optical axis AX1. It can be said that they are arranged substantially symmetrically. The light SB1 emitted from the light emitting surface 16a of the light source 11a of the first light source element 14a exhibits a relatively wide divergence angle in the Y direction which is the horizontal direction and a relatively narrow divergence angle in the Z direction which is the vertical direction ( See FIGS. 5B and 5C). On the other hand, since the light emitting surface 16a of the light source 11a is long in the vertical direction, the divergence angle of the light SB1 is initially wide in the horizontal Y direction, but on the downstream side of the optical path of the first reflecting portion 31a (specifically, the light source 11a After a few hundred mm, that is, about 50 mm in front of the optical window 63), the aspect ratio of the aspect ratio becomes 1: 1, and then becomes wider in the vertical Z direction corresponding to the sub-scanning direction than in the horizontal Y direction. Similarly, the light SB2 emitted from the light emitting surface 16b of the light source 11b of the second light source element 14b exhibits a relatively wide divergence angle in the X direction which is the horizontal direction and a relatively narrow divergence angle in the Z direction which is the vertical direction. (See FIGS. 5E and 5F). On the other hand, since the light emitting surface 16b of the light source 11b is long in the vertical direction, the divergence angle of the light SB2 is initially wide in the horizontal X direction, but the vertical and horizontal aspect ratio is 1: on the downstream side of the optical path of the first reflecting portion 31a. After that, it becomes wider in the vertical Z direction corresponding to the sub-scanning direction than in the horizontal Y direction.
図6Aに示すように、下側に配置された第1光源要素14aの光源11aから射出された光SB1は、走査用ミラー31を経た遠方において相対的に下側に投影されて下側領域を照明し、副走査方向に関して上側に配置された第2光源要素14bの光源11bから射出された光SB2は、走査用ミラー31を経た遠方において相対的に上側に投影されて上側領域を照明する。
As shown in FIG. 6A, the light SB1 emitted from the light source 11a of the first light source element 14a disposed on the lower side is projected relatively lower in the distance through the scanning mirror 31, and the lower region is projected. The light SB2 that is illuminated and emitted from the light source 11b of the second light source element 14b disposed on the upper side in the sub-scanning direction is projected relatively upward in the distance through the scanning mirror 31 to illuminate the upper region.
図6Bに概念的に示すように、一対の光源11a,11bからの光SB1,SB2は、走査用ミラー31に入射する前後で、副走査方向に関して射出光軸AX1を挟んで交差するような光路をとる。ただし、走査用ミラー31での2回の反転によって上下が反転するので、投光される光SB1,SB2は、コリメーター部18による上下反転と、走査用ミラー31による上下反転とを受けて、図6Aに示すように結果的に元の上下関係が維持される。両光源11a,11bからの光SB1,SB2をコリメーター部18によって副走査方向に対応する上下方向に関して交差させる構成とすることで、投光系10を副走査方向に比較的小型化することができる。
As conceptually shown in FIG. 6B, the light paths SB1 and SB2 from the pair of light sources 11a and 11b cross the optical axis AX1 with respect to the sub-scanning direction before and after entering the scanning mirror 31. Take. However, since the top and bottom are inverted by two inversions at the scanning mirror 31, the projected light SB1 and SB2 are subjected to upside down by the collimator unit 18 and upside down by the scanning mirror 31. As a result, the original vertical relationship is maintained as shown in FIG. 6A. By making the light beams SB1 and SB2 from the light sources 11a and 11b intersect with each other in the vertical direction corresponding to the sub-scanning direction by the collimator unit 18, the light projecting system 10 can be made relatively small in the sub-scanning direction. it can.
図6Aに示すように、走査用ミラー31の回転に伴って一対の光源11a,11bによる走査領域AR1,AR2は、光SB1,SB2を主走査方向であるY方向に移動させた軌跡を形成し、Y方向に細長く投影されている。より詳細には、光SB1,SB2からなるレーザー光(投光ビーム)L1は、物体側においてZ方向又は副走査方向に細長く延びて投光角度の範囲をカバーしている。また、光SB1,SB2からなるレーザー光(投光ビーム)L1は、走査用ミラー31の回転に伴って照射角度の範囲でY方向又は主走査方向に移動する。レーザー光(投光ビーム)L1は、各光源11a,11bによる投光視野の副走査方向の位置が異なるように出射され、投光視野のうち隣接する投光視野に対応する光源11a,11bは、異なるタイミングで発光する(非同時発光)。
As shown in FIG. 6A, as the scanning mirror 31 rotates, the scanning areas AR1 and AR2 formed by the pair of light sources 11a and 11b form a locus in which the light SB1 and SB2 are moved in the Y direction, which is the main scanning direction. , And projected in the Y direction. More specifically, the laser beam (projection beam) L1 composed of the light beams SB1 and SB2 extends in the Z direction or the sub-scanning direction on the object side to cover the range of projection angles. Further, the laser light (projected beam) L1 composed of the light SB1 and SB2 moves in the Y direction or the main scanning direction within the range of the irradiation angle as the scanning mirror 31 rotates. The laser light (projection beam) L1 is emitted so that the positions of the projection fields of the light sources 11a and 11b in the sub-scanning direction are different, and the light sources 11a and 11b corresponding to the adjacent projection fields of the projection field are , Emit light at different timing (non-simultaneous light emission).
図4A及び4B等に戻って、受光系20は、穴あきミラー21と、受光レンズ22と、ミラー23と、受光素子24とを備える。
4A and 4B, the light receiving system 20 includes a perforated mirror 21, a light receiving lens 22, a mirror 23, and a light receiving element 24.
穴あきミラー21は、走査用ミラー31と受光レンズ22との間の光路上に配置される光路折曲ミラーである。穴あきミラー21の開口21aは、穴あきミラー21の中央又はその周辺の適所に形成されている。射出光軸AX1と入射光軸AX2とは、走査用ミラー31に隣接する区間で略一致して配置されている。つまり、開口21aの略中心を投光系10の射出光軸AX1及び入射光軸AX2が通っており、開口21aを通る射出光軸AX1又は入射光軸AX2の周辺において、光源11a,11bからの光SB1,SB2は、副走査方向に対応する上下のZ方向に関して絞られており、主走査方向に対応する左右のY方向に関してコリメーターレンズ12a,12bによって拡がりが抑えられている。結果的に、光SB1,SB2は、開口21aを無駄なく通過する。穴あきミラー21を用いることで、投光系10及び受光系20のサイズを副走査方向に関して小さく収めることができるとともに、受光光量を大きくすることができる。
The perforated mirror 21 is an optical path bending mirror disposed on the optical path between the scanning mirror 31 and the light receiving lens 22. The opening 21a of the perforated mirror 21 is formed at an appropriate position in the center of the perforated mirror 21 or in the vicinity thereof. The emission optical axis AX1 and the incident optical axis AX2 are disposed substantially coincident with each other in the section adjacent to the scanning mirror 31. That is, the exit optical axis AX1 and the incident optical axis AX2 of the light projecting system 10 pass through the approximate center of the opening 21a, and the light from the light sources 11a and 11b around the exit optical axis AX1 or the incident optical axis AX2 passing through the opening 21a. The lights SB1 and SB2 are narrowed in the upper and lower Z directions corresponding to the sub-scanning direction, and spread is suppressed by the collimator lenses 12a and 12b in the left and right Y directions corresponding to the main scanning direction. As a result, the light SB1 and SB2 pass through the opening 21a without waste. By using the perforated mirror 21, the size of the light projecting system 10 and the light receiving system 20 can be reduced in the sub-scanning direction, and the amount of received light can be increased.
走査用ミラー31の第2反射部31bを経て第1反射部31aで反射された戻り光L2は、穴あきミラー(光路折曲ミラー)21の反射面21bで反射されて光路を直交方向に折り曲げられる。この際、開口21aによって戻り光L2の一部が光路外に漏れて損失となるが、第1反射部31aに対する開口21aの面積的な割合が比較的小さければ検出精度の低下には繋がらない。
The return light L2 reflected by the first reflecting portion 31a through the second reflecting portion 31b of the scanning mirror 31 is reflected by the reflecting surface 21b of the perforated mirror (optical path folding mirror) 21 and bends the optical path in the orthogonal direction. It is done. At this time, a part of the return light L2 leaks out of the optical path through the opening 21a and is lost, but if the area ratio of the opening 21a to the first reflecting portion 31a is relatively small, the detection accuracy does not decrease.
受光レンズ22は、戻り光L2のビーム径を絞り込む役割を有し、ミラー23は、受光レンズ22を経た戻り光L2を受光素子24に導く役割を有する。受光素子24とミラー23との間には、戻り光L2すなわちレーザー光L1の波長以外の可視光線等を遮断するバンドパスタイプのフィルター26が配置されている。これらの受光レンズ22やミラー23は、入射光軸AX2に沿って配列されている。
The light receiving lens 22 has a role of narrowing the beam diameter of the return light L2, and the mirror 23 has a role of guiding the return light L2 having passed through the light receiving lens 22 to the light receiving element 24. Between the light receiving element 24 and the mirror 23, a band pass type filter 26 that blocks visible light other than the wavelength of the return light L2, that is, the laser light L1, is disposed. The light receiving lens 22 and the mirror 23 are arranged along the incident optical axis AX2.
受光素子24は、受光レンズ22及びミラー23を経た戻り光L2を検出する。受光素子24は、例えばCMOS、CCDその他の半導体デバイスであり、戻り光L2の強度を検出するとともに、副走査方向に対応する上下のZ方向に位置分解能を有する。つまり、受光素子24は、副走査方向に2画素以上を有する。受光素子24は、分割した投光視野に対応する光検出領域DA1,DA2で戻り光L2を受光し、隣接する光検出領域DA1,DA2は、異なるタイミングで戻り光L2を受光する(非同時受光)。
The light receiving element 24 detects the return light L2 that has passed through the light receiving lens 22 and the mirror 23. The light receiving element 24 is, for example, a CMOS, CCD, or other semiconductor device, and detects the intensity of the return light L2, and has position resolution in the vertical Z direction corresponding to the sub-scanning direction. That is, the light receiving element 24 has two or more pixels in the sub-scanning direction. The light receiving element 24 receives the return light L2 in the light detection areas DA1 and DA2 corresponding to the divided projection fields, and the adjacent light detection areas DA1 and DA2 receive the return light L2 at different timings (non-simultaneous light reception). ).
図7を参照して、受光素子24の光検出面24aの具体例について説明する。光検出面24aは、その長手方向が副走査方向となっている。光検出面24aは、6つの画素24pで構成され、6つの画素24pは、副走査方向に対応する上下のZ方向に配列されている。つまり、光検出面24aは、副走査方向に対応するZ方向に関して6画素の構成であり、主走査方向に対応する左右のY方向に関して1画素の構成である。受光素子24の光検出面24aは、上下のZ方向や左右のY方向に関してレーザー光L1の投光角度の範囲内にある検出対象OBによって逆行する方向に反射された戻り光L2を取り込める幅を有する。参考のため、戻り光L2のうち光源11aからの光SB1に起因する検出光L21と、光源11bからの光SB2に起因する検出光L22とを光検出面24a上に概念的に示す。
A specific example of the light detection surface 24a of the light receiving element 24 will be described with reference to FIG. The longitudinal direction of the light detection surface 24a is the sub-scanning direction. The light detection surface 24a includes six pixels 24p, and the six pixels 24p are arranged in the upper and lower Z directions corresponding to the sub-scanning direction. That is, the light detection surface 24a has a configuration of 6 pixels with respect to the Z direction corresponding to the sub-scanning direction and a configuration of 1 pixel with respect to the left and right Y directions corresponding to the main scanning direction. The light detection surface 24a of the light receiving element 24 has a width capable of capturing the return light L2 reflected in the reverse direction by the detection target OB within the projection angle range of the laser light L1 with respect to the vertical Z direction and the horizontal Y direction. Have. For reference, the detection light L21 due to the light SB1 from the light source 11a and the detection light L22 due to the light SB2 from the light source 11b in the return light L2 are conceptually shown on the light detection surface 24a.
レーザーレーダー装置100又は走査型の光学系101の動作の概要につていて説明すると、主制御部50の制御下で受光系20の一対の光源11a,11bを周期的に発光させることで、コリメーター部18で合成されたレーザー光(投光ビーム)L1が穴あきミラー(光路折曲ミラー)21の開口21aを通過し、走査用ミラー31を経た上下の副走査方向に長いレーザー光L1は、横の主走査方向に主走査される。これと同期させて受光系20の受光素子24を動作させることで、検出対象OBからの戻り光L2を検出して、検出対象OBまでの距離や配置等を計測することができる。
The outline of the operation of the laser radar device 100 or the scanning optical system 101 will be described. The pair of light sources 11a and 11b of the light receiving system 20 are periodically caused to emit light under the control of the main control unit 50. The laser beam (projection beam) L1 synthesized by the meter unit 18 passes through the opening 21a of the perforated mirror (optical path bending mirror) 21 and passes through the scanning mirror 31, and the laser beam L1 that is long in the upper and lower sub-scanning directions is The main scanning is performed in the horizontal main scanning direction. By operating the light receiving element 24 of the light receiving system 20 in synchronism with this, it is possible to detect the return light L2 from the detection target OB and measure the distance, arrangement, etc. to the detection target OB.
既述のように、隣接する投光視野に対応する光源11a,11bは、異なるタイミング(具体的には、第1発光タイミング及び第2発光タイミング)で発光する。図8Aに示すように、第1発光タイミングにおいて、主制御部50は、発光タイミング制御部41を動作させ、複数の11a,11bのうち光源11bのみを発光させる。この際、主制御部50は、受光タイミング制御部42を動作させ、受光側の受光素子24において、スイッチング部43により上側の光検出領域DA2(つまり、3つの画素24p)で検出された検出光L22を処理回路44で信号処理させる。よって、図示のように、下側の光検出領域DA1に戻り光L2が入射しても下側では光を検知しないようになっている。また、図8Bに示すように、第1発光タイミングとは異なる第2発光タイミングにおいて、主制御部50は、発光タイミング制御部41を動作させ、複数の11a,11bのうち光源11aのみを発光させる。この際、主制御部50は、受光タイミング制御部42を動作させ、受光側の受光素子24において、スイッチング部43により下側の光検出領域DA1(つまり、3つの画素24p)で検出された検出光L21を処理回路44で信号処理させる。よって、図示のように、上側の光検出領域DA2に戻り光L2が入射しても上側では光を検知しないようになっている。
As described above, the light sources 11a and 11b corresponding to the adjacent light projection fields emit light at different timings (specifically, the first light emission timing and the second light emission timing). As shown in FIG. 8A, at the first light emission timing, the main control unit 50 operates the light emission timing control unit 41 to cause only the light source 11b to emit light among the plurality of 11a and 11b. At this time, the main control unit 50 operates the light reception timing control unit 42 to detect the detection light detected in the upper light detection area DA2 (that is, the three pixels 24p) by the switching unit 43 in the light receiving element 24 on the light receiving side. L22 is signal-processed by the processing circuit 44. Therefore, as shown in the drawing, even if the return light L2 enters the lower light detection area DA1, light is not detected on the lower side. Further, as shown in FIG. 8B, at a second light emission timing different from the first light emission timing, the main control unit 50 operates the light emission timing control unit 41 to emit only the light source 11a among the plurality of 11a and 11b. . At this time, the main control unit 50 operates the light reception timing control unit 42, and in the light receiving element 24 on the light receiving side, detection detected in the lower light detection area DA1 (that is, the three pixels 24p) by the switching unit 43. The light L21 is signal-processed by the processing circuit 44. Therefore, as shown in the drawing, even if the return light L2 enters the upper light detection area DA2, light is not detected on the upper side.
以上説明した走査型の光学系では、複数の光源11a,11bによるレーザー光(投光ビーム)L1を投光視野の副走査方向の位置が異なるように出射させ、隣接する投光視野に対応する光源11a,11bを異なるタイミングで発光させる。これにより、遠距離でのエネルギー密度が増加するため、より遠距離の対象物である検出対象OBを検知することができる。ここで、遠距離では、光源11a,11bのサイズと光学系101の焦点距離との関係が、光源11a,11bから出射されるビーム径に対し支配的に影響する。一方、近距離でのエネルギー密度は減少するため、アイセーフによいものとできる。ここで、近距離では、光源11a,11bからのビームの拡がりと光学系101の焦点距離とが、ビーム径に対し支配的に影響する。また、隣接する投光視野に対応する光源11a,11bを異なるタイミングで発光させることにより、隣接する投光視野が互いに重複しないため、比較的安全性の高いClass1のアイセーフを満たすことができる。また、隣接する光検出領域DA1,DA2における異なるタイミングでの受光、すなわち検出可能な光検出領域DA1,DA2の切り替えにより、戻り光L2のビームが対応する光検出領域DA1,DA2から多少はみ出して入射してもクロストークによる誤検知を防止することができ、位置合わせの精度を高める必要がなく、コストを抑えることができる。
In the scanning optical system described above, the laser light (projection beam) L1 from the plurality of light sources 11a and 11b is emitted so that the positions of the projection fields in the sub-scanning direction are different, and corresponds to the adjacent projection fields. The light sources 11a and 11b are caused to emit light at different timings. Thereby, since the energy density in a long distance increases, it is possible to detect the detection target OB that is a longer distance object. Here, at a long distance, the relationship between the size of the light sources 11a and 11b and the focal length of the optical system 101 has a dominant influence on the beam diameter emitted from the light sources 11a and 11b. On the other hand, since the energy density at a short distance decreases, it is possible to improve the eye safety. Here, at a short distance, the spread of the beams from the light sources 11a and 11b and the focal length of the optical system 101 have a dominant influence on the beam diameter. In addition, by causing the light sources 11a and 11b corresponding to the adjacent light projection fields to emit light at different timings, the adjacent light projection fields do not overlap with each other, so that it is possible to satisfy the relatively safe Class 1 eye safe. In addition, by receiving light at different timings in the adjacent light detection areas DA1 and DA2, that is, by switching the detectable light detection areas DA1 and DA2, the beam of the return light L2 protrudes slightly from the corresponding light detection areas DA1 and DA2. Even in this case, erroneous detection due to crosstalk can be prevented, and there is no need to increase the accuracy of alignment, thereby reducing the cost.
〔第2実施形態〕
以下、第2実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第2実施形態に係る走査型の光学系等は、第1実施形態の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態と同様である。 [Second Embodiment]
Hereinafter, a scanning optical system according to the second embodiment and a laser radar device incorporating the same will be described. Note that the scanning optical system and the like according to the second embodiment are obtained by partially changing the scanning optical system and the like of the first embodiment, and items that are not particularly described are the same as those of the first embodiment. .
以下、第2実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第2実施形態に係る走査型の光学系等は、第1実施形態の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態と同様である。 [Second Embodiment]
Hereinafter, a scanning optical system according to the second embodiment and a laser radar device incorporating the same will be described. Note that the scanning optical system and the like according to the second embodiment are obtained by partially changing the scanning optical system and the like of the first embodiment, and items that are not particularly described are the same as those of the first embodiment. .
図9を参照して、本実施形態の場合、光源11a,11bはそれぞれ主走査方向に対応する方向(図面横方向)にスタックされた構造を有する。隣接する光源11a,11bは、スタック構造の各層の発光タイミングがずれるようなタイミングで発光させている。光源11a,11bの幅Wは、各スタック要素SCの発光域の幅d1と発光域間の幅d2とをスタック数X個分合わせたものである。ここで、幅d1及び幅d2を合計した幅(d1+d2)は、投光の空間周期となっている。また、幅Wは、各光源11a,11bについて合成した空間周期を達成するように調整されている。発光域の幅d1に対応する時間分ずれたタイミングで光源11a,11bを発光させることにより、対象物である検出対象OBを漏れなく、かつ隙間なく検知することができる。図9の例では、光源11a,11bはそれぞれ3つのスタック要素SCで構成されている。図面では、上下の光源11a,11bが横方向にズレて表示されているが、実際は横方向に空間的に一致して配置されており、発光タイミングにズレを生じさせることで投影空間でも横方向のズレが生じている。第1発光タイミング(図中の発光1)において発光した光源11bに対して、第2発光タイミング(図中の発光2)において発光した光源11aは発光域の幅d1に対応する時間分ずらして発光させている。レーザーレーダー装置100の動作中、光源11a,11bは、これらの発光タイミングを繰り返す。図9の例で説明すると、次の第1発光タイミング(図中の発光3)において、光源11bは、直前の第2発光タイミング(図中の発光2)において発光した光源11aに対して発光域の幅d1に対応する時間分ずらして発光させる。また、次の第2発光タイミング(図中の発光4)において、光源11aは、直前の第1発光タイミング(図中の発光3)において発光した光源11bに対して発光域の幅d1に対応する時間分ずらして発光させる。
Referring to FIG. 9, in the case of the present embodiment, light sources 11a and 11b each have a structure stacked in a direction corresponding to the main scanning direction (the horizontal direction in the drawing). The adjacent light sources 11a and 11b emit light at a timing at which the light emission timing of each layer of the stack structure is shifted. The width W of the light sources 11a and 11b is obtained by combining the width d1 of the light emission area of each stack element SC and the width d2 between the light emission areas by the number of stacks X. Here, the total width (d1 + d2) of the width d1 and the width d2 is a spatial period of light projection. Further, the width W is adjusted so as to achieve a combined spatial period for each of the light sources 11a and 11b. By causing the light sources 11a and 11b to emit light at a timing shifted by a time corresponding to the width d1 of the light emitting area, it is possible to detect the detection target OB that is an object without leakage and without a gap. In the example of FIG. 9, each of the light sources 11a and 11b is composed of three stack elements SC. In the drawing, the upper and lower light sources 11a and 11b are displayed while being shifted in the horizontal direction, but are actually arranged spatially in the horizontal direction, and the horizontal direction is also generated in the projection space by causing a shift in the light emission timing. There is a gap. The light source 11a emitted at the second light emission timing (light emission 2 in the drawing) is shifted by the time corresponding to the width d1 of the light emitting area with respect to the light source 11b emitted at the first light emission timing (light emission 1 in the drawing). I am letting. During the operation of the laser radar device 100, the light sources 11a and 11b repeat these light emission timings. In the example of FIG. 9, at the next first light emission timing (light emission 3 in the figure), the light source 11b emits light with respect to the light source 11a emitted at the immediately preceding second light emission timing (light emission 2 in the figure). The light is emitted while being shifted by a time corresponding to the width d1. Further, at the next second light emission timing (light emission 4 in the figure), the light source 11a corresponds to the width d1 of the light emission area with respect to the light source 11b emitted at the immediately preceding first light emission timing (light emission 3 in the figure). Turn on the light by shifting the time.
〔第3実施形態〕
以下、第3実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第3実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Third Embodiment]
Hereinafter, a scanning optical system according to the third embodiment and a laser radar device incorporating the same will be described. It should be noted that the scanning optical system according to the third embodiment is a part of the scanning optical system according to the first embodiment, etc., and items not specifically described are the same as those of the first embodiment. It is.
以下、第3実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第3実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Third Embodiment]
Hereinafter, a scanning optical system according to the third embodiment and a laser radar device incorporating the same will be described. It should be noted that the scanning optical system according to the third embodiment is a part of the scanning optical system according to the first embodiment, etc., and items not specifically described are the same as those of the first embodiment. It is.
本実施形態において、M個の光源の発光周期はM個の点灯を順次可能にするものであり、光源は走査用ミラー31のn回転目と走査用ミラー31のn+1回転目との切り替えの際に、発光タイミングを1画素ΔP分ずらしている。ここで、値Mは2以上の自然数であり、値nは1以上の自然数である。これにより、発光タイミングをずらしながらも副走査方向、すなわち縦方向の画素ずれが低減することになり、対象物である検出対象OBの形状を正確に認識することができる。図10Aの例では、3個の光源LD1,LD2,LD3で構成されており、図10Bに示すように、各光源LD1,LD2,LD3は、発光周期Tの間隔でそれぞれ発光し、各光源LD1,LD2,LD3の第1~第3発光タイミングは、T/M(この場合、M=3)の間隔で異なっている。なお、図10Aに示す光源LD1,LD2,LD3の配置は、説明の便宜上、光路の折り曲げ等を無くした仮想的な配置となっている。図11A、11B、及び11Cは、例示として1回転目、2回転目、及び3回転目の投光状態又は投光視野をそれぞれ示している。既述のように、図2A等に示す走査用ミラー31の場合、レーザー光L1が縦方向に4段階に副走査されており、図11A~11Cは、1段階の走査中の投光視野の一部の特定面QAを示している。各図の上段は光源LD1の像Q1からなる投影パターンP1を示し、中段は光源LD2の像Q2からなる投影パターンP2を示し、下段は光源LD3の像Q3からなる投影パターンP2を示す。図11A~11Cにおいて、3個の光源LD1,LD2,LD3の発光周期Tは3個の点灯を順次可能にするもの(個別の発光周期に対応する間隔又は空間周期T1~T3(発光周期Tに相当))となっている。また、走査用ミラー31の1回転目と2回転目との切り替え、及び2回転目と3回転目との切り替えの際に、光源LD1,LD2,LD3は、発光周期に対応する間隔又は空間周期T1~T3の発光タイミングを1画素ΔPに相当するT/3ずらしている。4回転目以降も同様の発光タイミングでレーザーレーダー装置100を動作させる。なお、走査用ミラー31の3回転分の投光を積算した空間周期は、T/3となる。
In the present embodiment, the light emission period of the M light sources sequentially enables M lighting, and the light source is switched between the n-th rotation of the scanning mirror 31 and the n + 1-th rotation of the scanning mirror 31. In addition, the light emission timing is shifted by one pixel ΔP. Here, the value M is a natural number of 2 or more, and the value n is a natural number of 1 or more. Thereby, the pixel shift in the sub-scanning direction, that is, the vertical direction is reduced while shifting the light emission timing, and the shape of the detection target OB that is the target can be accurately recognized. In the example of FIG. 10A, the light source is configured by three light sources LD1, LD2, and LD3. As shown in FIG. 10B, each of the light sources LD1, LD2, and LD3 emits light at intervals of the light emission period T, and each light source LD1. , LD2 and LD3 have different first to third light emission timings at intervals of T / M (in this case, M = 3). The arrangement of the light sources LD1, LD2, and LD3 shown in FIG. 10A is a virtual arrangement that eliminates the bending of the optical path and the like for convenience of explanation. FIGS. 11A, 11B, and 11C show the projection state or projection field of the first rotation, the second rotation, and the third rotation, respectively, as an example. As described above, in the case of the scanning mirror 31 shown in FIG. 2A and the like, the laser light L1 is sub-scanned in four stages in the vertical direction, and FIGS. 11A to 11C show the projected field of view during the one-stage scanning. Some specific planes QA are shown. The upper part of each figure shows a projection pattern P1 composed of an image Q1 of the light source LD1, the middle part shows a projection pattern P2 composed of an image Q2 of the light source LD2, and the lower part shows a projection pattern P2 composed of an image Q3 of the light source LD3. In FIGS. 11A to 11C, the light emission period T of the three light sources LD1, LD2, and LD3 sequentially enables three lighting (intervals corresponding to individual light emission periods or spatial periods T1 to T3 (the light emission period T). Equivalent)). Further, when the scanning mirror 31 is switched between the first rotation and the second rotation and between the second rotation and the third rotation, the light sources LD1, LD2, and LD3 have intervals or spatial periods corresponding to the light emission period. The light emission timings of T1 to T3 are shifted by T / 3 corresponding to one pixel ΔP. The laser radar device 100 is also operated at the same light emission timing after the fourth rotation. Note that the spatial period obtained by integrating the light projections for three rotations of the scanning mirror 31 is T / 3.
〔第4実施形態〕
以下、第4実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第4実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Fourth Embodiment]
Hereinafter, a scanning optical system according to the fourth embodiment and a laser radar device incorporating the same will be described. It should be noted that the scanning optical system according to the fourth embodiment is a partial modification of the scanning optical system according to the first embodiment, and the matters not specifically described are the same as those of the first embodiment. It is.
以下、第4実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第4実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Fourth Embodiment]
Hereinafter, a scanning optical system according to the fourth embodiment and a laser radar device incorporating the same will be described. It should be noted that the scanning optical system according to the fourth embodiment is a partial modification of the scanning optical system according to the first embodiment, and the matters not specifically described are the same as those of the first embodiment. It is.
図12A及び12Bに示すように、第4実施形態の場合、投光系10と受光系20とが簡易に分離されており、投光系10と受光系20とが副走査方向又はZ方向に関して異なる位置に配置されている。つまり、投光系10の射出光軸AX1と入射光軸AX2とは、ミラー23と走査用ミラー31との間の区間において、互いに平行に隣接して配置されており、Z方向又は副走査方向に離間している。つまり、走査用ミラー31に隣接する位置で、射出光軸AX1と入射光軸AX2とは、副走査方向に対応するZ方向に異なる位置に配置されており、主走査方向に対応するY方向に関しては平面視で同じ位置に重なって見えるように配置されている。本実施形態の場合、投光系10と受光系20とを簡易に分離した構成となっている。
As shown in FIGS. 12A and 12B, in the case of the fourth embodiment, the light projecting system 10 and the light receiving system 20 are simply separated, and the light projecting system 10 and the light receiving system 20 are related to the sub-scanning direction or the Z direction. They are located at different positions. That is, the emission optical axis AX1 and the incident optical axis AX2 of the light projecting system 10 are arranged adjacent to each other in parallel in the section between the mirror 23 and the scanning mirror 31, and are in the Z direction or the sub scanning direction. Are separated. That is, at the position adjacent to the scanning mirror 31, the exit optical axis AX1 and the incident optical axis AX2 are arranged at different positions in the Z direction corresponding to the sub-scanning direction, and the Y direction corresponding to the main scanning direction. Are arranged so as to overlap each other in plan view. In the present embodiment, the light projecting system 10 and the light receiving system 20 are simply separated.
受光系20は、受光レンズ22と、ミラー23と、受光素子24とを備える。この場合、射出光軸AX1と入射光軸AX2とを副走査方向に関して位置ずれさせて配置しているので、穴あきミラーは不要である。受光素子24の光検出面24aは、ミラー23による光路折り曲げにより、第1実施形態の場合と異なり、X方向に延びているが、X方向は副走査方向に対応する。
The light receiving system 20 includes a light receiving lens 22, a mirror 23, and a light receiving element 24. In this case, since the emission optical axis AX1 and the incident optical axis AX2 are arranged so as to be displaced with respect to the sub-scanning direction, a perforated mirror is unnecessary. Unlike the first embodiment, the light detection surface 24a of the light receiving element 24 extends in the X direction due to the optical path bending by the mirror 23, but the X direction corresponds to the sub-scanning direction.
〔第5実施形態〕
以下、第5実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第5実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Fifth Embodiment]
Hereinafter, a scanning optical system according to a fifth embodiment and a laser radar device incorporating the same will be described. Note that the scanning optical system and the like according to the fifth embodiment are obtained by partially changing the scanning optical system and the like according to the first embodiment, and items not specifically described are the same as those of the first embodiment and the like. It is.
以下、第5実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第5実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Fifth Embodiment]
Hereinafter, a scanning optical system according to a fifth embodiment and a laser radar device incorporating the same will be described. Note that the scanning optical system and the like according to the fifth embodiment are obtained by partially changing the scanning optical system and the like according to the first embodiment, and items not specifically described are the same as those of the first embodiment and the like. It is.
図13A及び13Bに示すように、第5実施形態の場合、投光系10において、第1光源要素14aと第2光源要素14bとが射出光軸AX1を挟んで上下の副走査方向に鏡像配置されている。つまり、第1の光源11aと第2の光源11bとは、射出光軸AX1に対して厳密に対称に配置されている。この場合、一対のコリメーターレンズ12a,12bを合わせたものがコリメーター部18となっており、光路合成用のミラーが不要となっている。また、第1光源要素14aにおいて光源11aは、コリメーター部18を構成するコリメーターレンズ12aに対して副走査方向に非対称的となるように軸外し状態で配置されており、第1光源要素14bにおいて光源11bは、コリメーター部18を構成するコリメーターレンズ12bに対して副走査方向に非対称的となるように軸外し状態で配置されている。
As shown in FIGS. 13A and 13B, in the case of the fifth embodiment, in the light projecting system 10, the first light source element 14a and the second light source element 14b are mirror images arranged in the vertical sub-scanning direction across the emission optical axis AX1. Has been. That is, the first light source 11a and the second light source 11b are disposed strictly symmetrically with respect to the emission optical axis AX1. In this case, a combination of the pair of collimator lenses 12a and 12b is a collimator unit 18, and a mirror for synthesizing the optical path is not necessary. In the first light source element 14a, the light source 11a is arranged off-axis so as to be asymmetric in the sub-scanning direction with respect to the collimator lens 12a constituting the collimator unit 18, and the first light source element 14b. The light source 11b is arranged off-axis so as to be asymmetric in the sub-scanning direction with respect to the collimator lens 12b constituting the collimator unit 18.
図13A及び13Bに示す例では、受光系20が第1実施形態に示すものと同様であったが、受光系20を第4実施形態に示すものと同様として、投光用の光路と受光用の光路とを完全に分けることもできる。
In the example shown in FIGS. 13A and 13B, the light receiving system 20 is the same as that shown in the first embodiment, but the light receiving system 20 is the same as that shown in the fourth embodiment. It is also possible to completely separate the optical path.
〔第6実施形態〕
以下、第6実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第6実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Sixth Embodiment]
Hereinafter, a scanning optical system according to a sixth embodiment and a laser radar apparatus incorporating the same will be described. Note that the scanning optical system according to the sixth embodiment is a partial modification of the scanning optical system according to the first embodiment, and the items not specifically described are the same as those of the first embodiment. It is.
以下、第6実施形態に係る走査型の光学系及びこれを組み込んだレーザーレーダー装置について説明する。なお、第6実施形態に係る走査型の光学系等は、第1実施形態等の走査型の光学系等を一部変更したものであり、特に説明しない事項は、第1実施形態等と同様である。 [Sixth Embodiment]
Hereinafter, a scanning optical system according to a sixth embodiment and a laser radar apparatus incorporating the same will be described. Note that the scanning optical system according to the sixth embodiment is a partial modification of the scanning optical system according to the first embodiment, and the items not specifically described are the same as those of the first embodiment. It is.
図14に示すように、レーザーレーダー装置100は、第1実施形態と同様に、投光系10と、受光系20と、回転反射部30と、主制御部50と、外装部品60とを備える。本実施形態の回転反射部30の走査用ミラー31は、1回反射型のポリゴンミラーであり、光路折り曲げ用の第1反射部31aのみを有する。走査用ミラー31において、第1反射部31aの鏡面は、Z軸に対して傾斜しており、紙面上で下方向である-Z方向から入射したレーザー光L1を略直交する方向に反射し、紙面上で左方向の検出対象OB側へ導く。検出対象OBで反射された一部の戻り光L2は、レーザー光L1の経路と逆の経路をたどり、受光系20で検出される。この場合、図1の場合と異なり、走査用ミラー31の回転軸RXに垂直な紙面左右のX方向が副走査方向となっており、回転軸RXに垂直な紙面垂直なY方向が主走査方向となっている。
As shown in FIG. 14, the laser radar device 100 includes a light projecting system 10, a light receiving system 20, a rotary reflection unit 30, a main control unit 50, and an exterior component 60, as in the first embodiment. . The scanning mirror 31 of the rotary reflection unit 30 of this embodiment is a one-time reflection type polygon mirror, and includes only the first reflection unit 31a for bending the optical path. In the scanning mirror 31, the mirror surface of the first reflecting portion 31 a is inclined with respect to the Z axis, and reflects the laser beam L 1 incident from the −Z direction, which is the downward direction on the paper surface, in a direction substantially orthogonal to the scanning mirror 31. It is guided to the left side to be detected OB on the paper surface. A part of the return light L2 reflected by the detection target OB follows a path opposite to the path of the laser light L1, and is detected by the light receiving system 20. In this case, unlike the case of FIG. 1, the left and right X directions perpendicular to the rotation axis RX of the scanning mirror 31 are sub-scanning directions, and the Y direction perpendicular to the rotation axis RX is the main scanning direction. It has become.
以上、実施形態に即して本発明を説明したが、本発明は、上記実施形態等に限定されるものではない。例えば、受光素子24の光検出面24aを構成する画素24pは、6つに限らず、検出分解能に応じて適宜の数とできる。
As mentioned above, although this invention was demonstrated according to embodiment, this invention is not limited to the said embodiment etc. For example, the number of pixels 24p constituting the light detection surface 24a of the light receiving element 24 is not limited to six, and can be an appropriate number according to the detection resolution.
また、投光系10や受光系20を構成する光学素子は、図2A等に例示されるものに限らず、用途や仕様に応じて光路折り曲げ用のミラーを増やすこと、レンズを増やすこと等、様々な変更が可能である。
In addition, the optical elements constituting the light projecting system 10 and the light receiving system 20 are not limited to those illustrated in FIG. 2A and the like, and by increasing the number of mirrors for bending the optical path, increasing the number of lenses, etc. Various changes are possible.
また、上記実施形態において、受光素子24は、隣接する光検出領域DA1,DA2で異なるタイミングで戻り光L2を受光したが、フィルター等により、戻り光L2が分割した投光視野に対応する光検出領域DA1,DA2に略正確に入射するように制限すれば、戻り光L2を同じタイミングで受光してもよい。
In the above-described embodiment, the light receiving element 24 receives the return light L2 at different timings in the adjacent light detection areas DA1 and DA2, but the light detection corresponding to the light projection field divided by the return light L2 by a filter or the like. The return light L2 may be received at the same timing as long as it is limited to be incident on the areas DA1 and DA2 almost accurately.
Claims (8)
- 複数の光源と、前記光源からの光をそれぞれ入射させるコリメーター部とを有する投光系と、
前記投光系からの光を投光ビームとして反射し、主走査方向に走査させる走査用ミラーと、
前記走査用ミラーからの戻り光が入射する受光レンズと、
前記受光レンズを経た戻り光が入射する受光素子と、
を備え、
前記複数の光源は、前記主走査方向に直交する副走査方向に対応する方向に異なる位置に配置され、
前記受光素子は、前記複数の光源に対応する前記戻り光を検出可能に配置され、前記副走査方向に対応する方向に2画素以上を有し、
前記投光ビームは、各光源による投光視野の副走査方向の位置が異なるように出射され、
前記投光視野のうち隣接する投光視野に対応する前記光源は、異なるタイミングで発光する、走査型の光学系。 A light projecting system having a plurality of light sources and a collimator unit for making light from each of the light sources incident;
A scanning mirror that reflects light from the light projecting system as a light projecting beam and scans in the main scanning direction;
A light receiving lens on which return light from the scanning mirror is incident;
A light receiving element on which the return light passing through the light receiving lens is incident;
With
The plurality of light sources are arranged at different positions in a direction corresponding to a sub-scanning direction orthogonal to the main scanning direction,
The light receiving element is arranged to detect the return light corresponding to the plurality of light sources, and has two or more pixels in a direction corresponding to the sub-scanning direction,
The projection beam is emitted so that the position of the projection field of each light source in the sub-scanning direction is different,
A scanning optical system in which the light sources corresponding to adjacent ones of the projection fields emit light at different timings. - 前記受光素子は、各光源の投光視野に対応する光検出領域で前記戻り光を受光し、
隣接する前記光検出領域は、異なるタイミングで前記戻り光を受光する、請求項1に記載の走査型の光学系。 The light receiving element receives the return light in a light detection region corresponding to a light projection field of each light source,
The scanning optical system according to claim 1, wherein the adjacent light detection regions receive the return light at different timings. - 前記複数の光源の発光面は、前記主走査方向に対応する方向よりも前記副走査方向に対応する方向に長い、請求項1及び2のいずれか一項に記載の走査型の光学系。 3. The scanning optical system according to claim 1, wherein light emitting surfaces of the plurality of light sources are longer in a direction corresponding to the sub-scanning direction than in a direction corresponding to the main scanning direction.
- 前記受光素子で検出される前記戻り光を信号処理する処理回路をさらに備え、
前記受光素子と前記処理回路との間に前記受光素子の光検出領域を選択するスイッチング部を有する、請求項1から3までのいずれか一項に記載の走査型の光学系。 Further comprising a processing circuit for signal processing the return light detected by the light receiving element;
4. The scanning optical system according to claim 1, further comprising a switching unit that selects a light detection region of the light receiving element between the light receiving element and the processing circuit. 5. - 前記光源は前記主走査方向に対応する方向にスタック構造を有し、隣接する前記光源に対し、前記スタック構造の各層の発光タイミングがずれるようなタイミングで発光させる、請求項1から4までのいずれか一項に記載の走査型の光学系。 5. The light source according to claim 1, wherein the light source has a stack structure in a direction corresponding to the main scanning direction, and causes the adjacent light source to emit light at a timing at which the light emission timing of each layer of the stack structure is shifted. A scanning optical system according to claim 1.
- M個の前記光源の発光周期はM個の点灯を順次可能にするものであり、
前記光源は前記走査用ミラーのn回転目と前記走査用ミラーのn+1回転目との切り替えの際に、発光タイミングを1画素分ずらし、
値Mは2以上の自然数であり、値nは1以上の自然数である、請求項1から5までのいずれか一項に記載の走査型の光学系。 The light emission periods of the M light sources enable M lights to be turned on sequentially,
The light source shifts the light emission timing by one pixel when switching between the nth rotation of the scanning mirror and the n + 1th rotation of the scanning mirror,
6. The scanning optical system according to claim 1, wherein the value M is a natural number of 2 or more and the value n is a natural number of 1 or more. - 前記投光系から前記走査用ミラーに向かう射出光軸と、前記走査用ミラーから前記受光レンズに向かう入射光軸とは、前記走査用ミラーに隣接する区間で略一致して配置され、
前記走査用ミラーと前記受光レンズとの間の光路上に配置されて、前記射出光軸が通る開口を有する光路折曲ミラーを備える、請求項1から6までのいずれか一項に記載の走査型の光学系。 The exit optical axis from the light projecting system toward the scanning mirror and the incident optical axis from the scanning mirror toward the light receiving lens are disposed substantially coincident in a section adjacent to the scanning mirror,
The scanning according to any one of claims 1 to 6, further comprising an optical path bending mirror disposed on an optical path between the scanning mirror and the light receiving lens and having an opening through which the emission optical axis passes. Mold optics. - 請求項1から7までのいずれか一項に記載の走査型の光学系を備え、前記戻り光に基づいて対象物を検出する、レーザーレーダー装置。 A laser radar device comprising the scanning optical system according to any one of claims 1 to 7 and detecting an object based on the return light.
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