Optical scanning device and object detection device

Abstract

The invention provides an optical scanning device and an object detection device. The present invention addresses the problem of further expanding a measurement viewing angle. The optical scanning device is a device for detecting an object by irradiating light and receiving reflected light thereof. The optical scanning device is provided with: a deflector; a light source having at least a first light-emitting part that emits first light and a second light-emitting part that emits second light having different optical characteristics from the first light; a first optical element that is configured such that the first light emitted from the first light-emitting section is incident on the first optical element, and the first optical element reflects the first light and causes the first light to be incident toward the deflector; and a second optical element that is configured so that the second light emitted from the second light-emitting unit enters the second optical element, and that reflects the second light and causes the second light to enter the deflector, the first optical element having an optical property of reflecting the first light and transmitting the second light, and the second optical element having an optical property of reflecting the first light and transmitting the second light. The second optical element has an optical property of reflecting the second light and transmitting the first light.

Description

Technical Field The present disclosure relates to an optical scanning device and an object detection device. Background Art Examples of conventional optical scanning devices and object detection devices are described in, for example, Japanese Unexamined Patent Application Publication No. 2010-151958 (Patent Document 1). Prior Art Documents Patent Documents [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2010-151958 Summary of the Invention Problems to be Solved by the Invention One of the objects of the specific embodiments of the present disclosure is to further expand the measurement angle of view in an optical scanning device or the like. Means for Solving the Problems

[0001] An optical scanning device according to one embodiment of the present disclosure is a device for detecting an object by irradiating light and receiving the reflected light thereof, and the optical scanning device includes: A deflector; A light source having at least a first light emitting portion that emits first light and a second light emitting portion that emits second light having optical characteristics different from those of the first light; A first optical element configured to cause the first light emitted from the first light emitting portion to be incident on the first optical element, and the first optical element reflects the first light and causes the first light to be incident on the deflector; A second optical element configured to cause the second light emitted from the second light emitting portion to be incident on the second optical element, and the second optical element reflects the second light and causes the second light to be incident on the deflector, The first optical element has an optical characteristic of reflecting the first light and transmitting the second light, The second optical element has an optical characteristic of reflecting the second light and transmitting the first light.

[0002] An object detection device according to one embodiment of the present disclosure includes: The optical scanning device described in [1] above; A light receiving portion that detects the reflected light of the irradiation light emitted from the optical scanning device and generates a light receiving signal corresponding to the intensity of the reflected light; and A control portion that controls the operation of the optical scanning device and generates point cloud information based on the light receiving signal. According to the above configuration, it is possible to further expand the measurement angle of view in the optical scanning device and the object detection device including the optical scanning device. Brief Description of the Drawings Figure 1This is a diagram showing the structure of an object detection device according to an embodiment. Figure 2 This is a diagram for explaining an example layout of the scanning light source unit inside the housing. Figure 3 This is a diagram for explaining in detail the configuration of each dichroic mirror and the MEMS mirror. Figure 4 (A) of Figure 4 (B) of this is a diagram for explaining in more detail the relationship between each dichroic mirror and the laser trajectory when the laser passes through each dichroic mirror. Figure 5 This is a diagram showing an example combination of the transmission / reflection characteristics of each dichroic mirror and the wavelengths of each light emitting unit. Figure 6 This is a diagram showing an example of optical calculation of the measurement viewing angle based on the light scanning device according to the embodiment. Figure 7 (A) of Figure 7 (B) of this is a diagram for explaining in more detail the relationship between each reflective polarizer and the laser trajectory when the laser passes through each reflective polarizer in the first modified embodiment. Figure 8 This is a diagram showing an example combination of the transmission / reflection characteristics of each reflective polarizer and the wavelengths of each light emitting unit in the first modified embodiment. Figure 9 This is a diagram for explaining an example layout of the scanning light source unit inside the housing in the second modified embodiment. Figure 10 This is a diagram for explaining in more detail the relationship between each reflective polarizer and the laser trajectory when the laser passes through each reflective polarizer in the second modified embodiment. Figure 11 This is a diagram showing an example combination of the transmission / reflection characteristics of each reflective polarizer and the wavelengths of each light emitting unit in the second modified embodiment. Explanation of reference numerals 1: Controller; 2: Scanning light source unit (light scanning device); 3: Light receiving unit; 10: Measurement control unit; 11: Deflection control unit; 12: Lighting control unit; 13: Distance measurement unit; 14: Communication unit; 20: MEMS driver; 21: Light source driver; 22: MEMS mirror; 30: Lens; 31: Optical filter; 32: Photoelectric detector (light receiving element); 33: Light receiving circuit; LS: Light source; LS1, LS2, LS3, LS4: Light emitting units; R: Optical element (dichroic mirror / reflective polarizer); R1, R2, R3, R4: Dichroic mirrors; R11, R12, R13, R14: Reflective polarizers; T, T1, T2, T3, T4: Quarter-wave plates Detailed description of the embodiment Figure 1 This is a diagram showing the structure of an object detection device according to an embodiment. The object detection device of this embodiment is configured to perform optical scanning of an object space using a plurality of lasers (detection light) and receive reflected light, and detect point cloud information indicating the position, relative distance, etc. of an object existing in the object space using the reflected light. It is configured to include a controller 1, a scanning light source unit (optical scanning device) 2, and a light receiving unit 3. This object detection device is mounted on a vehicle, for example, and is used to detect objects (other vehicles, pedestrians, etc.) around the vehicle. In this case, the object detection device can be arranged, for example, on the roof of the vehicle, near the logo, near the interior rearview mirror, inside the headlamp, etc. The controller 1 controls the overall operation of the object detection device, and is configured to include a measurement control unit 10, a deflection control unit 11, a lighting control unit 12, a distance measurement unit 13, and a communication unit 14. This controller 1 can be implemented, for example, by using a computer system having a CPU, ROM, RAM, etc. and causing the computer system to execute a prescribed operation program. The measurement control unit 10 performs control to operate the deflection control unit 11, the lighting control unit 12, and the distance measurement unit 13, and controls the communication unit 14 to send the point cloud information, which is the measurement result of the distance measurement unit 13, to an external device (not shown). The deflection control unit 11 is controlled via the MEMS driver 20 of the scanning light source unit 2 to cause the MEMS mirror 22 to deflect periodically in an indicated angle change pattern (typically raster scanning with equal scanning line intervals). The lighting control unit 12 controls the light source driver 21 to cause the light source LS to emit laser light according to the pulse conditions indicated by the measurement control unit 10. The distance measurement unit 13 uses the laser generation indication time of the lighting control unit 12 and the received light signal obtained from the light receiving circuit 33 of the light receiving unit 3 to measure the mutual distance between the object in the object space based on the time difference between the laser emission time and the received light time. In addition, based on the laser emission time and the received light time, the measurement control unit 10 detects the three-dimensional position of the object. The communication unit 14 sends the obtained point cloud information (a set of three-dimensional positions) to an external device (not shown). The scanning light source unit 2 generates laser light with a narrow-angle beam and emits the laser light in various directions within a specified range. It is configured to include a MEMS driver 20, a light source driver 21, a MEMS mirror 22, a light source LS, and a dichroic mirror R. The MEMS driver 20 is connected to the MEMS mirror 22, receives the control of the deflection control unit 11 of the controller 1, generates a drive signal for controlling the operation of the MEMS mirror 22, and supplies it to the MEMS mirror 22. The light source driver 21 is connected to the light source LS, receives the control of the lighting control unit 12 of the controller 1, generates a drive signal for controlling the operation of the light source LS, and supplies it to the light source LS. The MEMS mirror 22 is a deflector that has a reflecting surface and is configured to be rotatable in two orthogonal directions respectively. The MEMS mirror 22 is disposed at a position where the laser light emitted from the light source LS can be incident on the reflecting surface from different directions respectively, and rotates based on the drive signal supplied from the MEMS driver 20 to scan each laser light in the object space. Each laser light is emitted from the opening 23 appropriately provided in the scanning light source unit 2 to the external object space. The light source LS is configured to include a plurality of light emitting units, and respectively generate a plurality of laser lights as narrow-angle beams (beams with a small divergence angle) for detection light based on the control signals from the lighting control unit 12, and emit each of the laser lights (pulse light). For example, the plurality of light emitting units are respectively laser diode elements. The laser lights emitted from the respective light emitting units of the light source LS are beams with a divergence angle based on the angular resolution of the object detection device (the same or less). As the respective light emitting units of the light source LS, for example, near-infrared photonic crystal lasers (PCSELs) can be used, but it is not limited thereto, as long as it is a light source LS that can emit narrow-angle beams for detection light. The plurality of light emitting units included in the light source LS include a first light emitting unit having specified optical characteristics and a second light emitting unit having optical characteristics different from those of the first light emitting unit. For example, the first light emitting unit and the second light emitting unit may be light emitting units with different emission wavelengths or different polarization directions. The light source LS of the present embodiment respectively includes two first light emitting units and two second light emitting units with different emission wavelengths. The light receiving unit 3 receives the reflected light generated by each laser light emitted from the light source LS and generates a light receiving signal, and is configured to include a lens 30, an optical filter 31, a photodetector (light receiving element) 32, and a light receiving circuit 33. The light receiving unit 3 may be configured as a coaxial optical system that receives light along the same optical path as the optical path from the light source LS to the MEMS mirror 22, or may be configured as a non-coaxial optical system that does not use the same optical path. The lens 30 condenses the reflected light generated by the laser light emitted from the light source LS. The optical filter 31 blocks light in a wavelength region different from the laser light emitted from the light source LS and allows light in the same wavelength region as the laser light emitted from the light source LS to pass through. The photodetector 32 detects the light incident via the optical filter 31. The light receiving circuit 33 generates a light receiving signal by performing specified signal processing (such as amplification, frequency filtering, etc.) on the output of the photodetector 32. The generated light receiving signal is supplied to the distance measurement unit 13 of the controller 1. Figure 2This is a diagram for explaining an example of the layout of the scanning light source unit within the housing. In the illustrated example of the configuration, the scanning light source unit 2 is within the housing. The substrate on which the MEMS driver 20 and the MEMS mirror 22 are mounted is arranged on the side in the figure, and the substrate on which the light source driver 21 and the light source LS are mounted is arranged on the bottom in the figure. Each dichroic mirror R is obliquely arranged on the side at a position opposite to the MEMS mirror 22. The MEMS driver 20 does not necessarily have to be on the same substrate as the MEMS mirror 22. If it causes the housing size to increase, it can also be separate. An opening is formed in the housing for the light reflected by the MEMS mirror 22 and emitted from the scanning light source unit 2 to pass through. The housing is made of, for example, aluminum. In order to prevent noise caused by interfering light, etc., it is preferable to perform black anodizing (alumite) processing on the housing. Each substrate is fixed to the housing by, for example, screws. The dichroic mirror R is fixed to the housing by bonding, for example. The light source LS includes a plurality of light emitting portions LS1, LS2, LS3, LS4 arranged in the depth direction along the plane of the paper. The dichroic mirror R includes a plurality of dichroic mirrors R1, R2, R3, R4 arranged in the depth direction along the plane of the paper. Each of the dichroic mirrors R1, R2, R3, R4 is arranged at a position where any of the lasers emitted from the respective light emitting portions of the light source LS can be incident. The MEMS mirror 22 is arranged at a position where the lasers incident on and reflected by each of the dichroic mirrors R1, R2, R3, R4 can be incident. Specifically, the light source LS and each of the dichroic mirrors R1, etc. are arranged such that the lasers emitted from the respective light emitting portions LS1, etc. of the light source LS are emitted in the Y direction in the figure and are incident on any of the dichroic mirrors R1, etc. Each of the dichroic mirrors R1, etc. is arranged at a position and an angle to reflect the incident light from the respective light emitting portions LS1, etc. and make them incident on the MEMS mirror 22. In addition, each of the dichroic mirrors R1, etc. is arranged at a position where any of the light reflected by the MEMS mirror 22 can be incident. Therefore, a part of each of the dichroic mirrors R1, etc. is arranged so as to cover the opening of the housing. In addition, the MEMS mirror 22 is arranged such that the lasers reflected by each of the dichroic mirrors R1, etc. travel in the Z direction in the figure, that is, in the direction of the opening of the housing and are incident. By swinging the MEMS mirror 22, the laser can be scanned. For example, the laser traveling in the Z direction shown in the figure is scanned in such a way that it moves up and down in the Y direction. The trajectory of the laser becomes the irradiation area. A part of the irradiation area includes the positions of the dichroic mirrors R1, etc. as shown in the figure. The light reflected by the MEMS mirror 22 and incident on the dichroic mirrors R1, etc. passes through the dichroic mirrors R1, etc. and advances from within the housing of the scanning light source unit 2 to the outside. In addition, when passing through the inside of the dichroic mirrors R1, etc., the laser refracts inside, so that the optical path deviates from that before incidence. However, the degree of deviation of this optical path is of the order of the thickness of the dichroic mirrors R1, etc., so it has no effect on the ranging performance and can be corrected on the light receiving unit 3 side. Here, each dichroic mirror R1, R2, R3, and R4 is formed by laminating several to several hundred layers of thin films of titanium oxide, tantalum oxide, niobium oxide, etc. as high-reflection refractive index components and thin films of silicon oxide, magnesium fluoride, etc. as low-reflection refractive index components on a glass substrate based on a specified optical design. In the present embodiment, each dichroic mirror R1, etc. is formed by laminating the above-mentioned thin films on a glass substrate, and is configured to have dimensions of about 3 mm in the short side, about 8 mm in the long side, and about 1 mm in thickness, for example. Moreover, a portion of about 3 mm to 4 mm along the long side direction is adhesively fixed to an inclined surface provided at a position facing the MEMS mirror 22 in the housing of the scanning light source unit 2, and the remaining portion not fixed to the inclined surface is arranged to hang down from the inclined surface. The adhesion of the dichroic mirrors R1, etc. can use, for example, a photocurable resin or a thermosetting resin. Figure 3 This is a diagram for explaining in detail the arrangement of each dichroic mirror and the MEMS mirror. In the figure, the arrangement diagrams in the YZ coordinate system, the XY coordinate system, the XZ coordinate system, and the perspective view are shown in order from the upper part. The Y-axis and Z-axis mentioned here correspond to the respective axes in the above Figure 2 , and the X-axis corresponds to the direction orthogonal to the Y-axis and Z-axis in the above Figure 2 . In addition, "before driving" shows the trajectory of the laser incident on each dichroic mirror R1, etc. and reflected when the MEMS mirror 22 is in the reference position, that is, the horizontal mechanical angle (swing angle) is 0° and the vertical mechanical angle (swing angle) is 0°. "After driving" shows the trajectory of the laser incident on each dichroic mirror R1, etc. and reflected when the MEMS mirror 22 is at the maximum mechanical angle in the present embodiment, that is, the horizontal mechanical angle (swing angle) is 8° and the vertical mechanical angle (swing angle) is 5°. In addition, hereinafter, the four light-emitting parts of the light source LS are respectively distinguished as LS1, LS2, LS3, and LS4. Each light-emitting part LS1, etc. exists below each dichroic mirror R1, etc. on the paper surface (not shown, only the reference numerals are shown). As shown in the arrangement diagrams in the XY coordinate system and the XZ coordinate system, the dichroic mirrors R1 to R4 are arranged at intervals along the X direction. In each of the arrangement diagrams in the XY coordinate system and the YZ coordinate system, the laser emitted from each light-emitting part LS1 to LS4 is emitted from the lower side of each dichroic mirror R1, etc. in the figure and is incident on each dichroic mirror R1, etc., and is incident on the MEMS mirror 22. The MEMS mirror 22 is arranged at a position closer to the inside than each dichroic mirror R1, etc. in the XY coordinate system, and is arranged on the left side relative to each dichroic mirror R1, etc. in the YZ coordinate system. The laser reflected by the MEMS mirror 22 sometimes passes through the dichroic mirrors R1, etc., and sometimes passes through the gaps between the dichroic mirrors R1, etc. The former is shown in the layout diagram of the XZ coordinates "before driving", and the latter is shown in the layout diagram of the XZ coordinates "after driving". When the MEMS mirror 22 is swung, before the swing angle reaches a certain angle, the laser is incident on the dichroic mirrors R1, etc. and passes through, and when the swing angle is after a certain angle, the laser passes through the gaps between the dichroic mirrors R1, etc. The reason why the laser passes through the dichroic mirrors R1, etc. will be described below. Figure 4 of (A) and Figure 4 of (B) are diagrams for explaining in more detail the relationship between each dichroic mirror and the laser trajectory in the case where the laser passes through the dichroic mirrors. Figure 5 is a diagram showing a combination example of the transmission / reflection characteristics of each dichroic mirror and the wavelengths of each light emitting part. In the present embodiment, for example, consider Figure 5 the 4 combinations shown. In this case, it is a combination in which the light emitting part LS1 and the light emitting part LS4 are paired, and a combination in which the light emitting part LS2 and the light emitting part LS3 are paired. The wavelengths of the light emitting parts LS1, etc. are exemplified, but are not limited thereto, and it is more preferable that there is a difference of 50 nm or more in each combination. Hereinafter, the Figure 5 combination example No. 1 shown will be described. As Figure 4 shown by the dotted line in (A) of, the laser (first light) with a wavelength of 900 nm emitted from the light emitting part LS1 is incident on the dichroic mirror R1 having a reflection characteristic for wavelengths of 900 nm or less and is reflected. After being reflected by the MEMS mirror 22, it passes through the dichroic mirror R4 having a reflection characteristic for wavelengths of 950 nm or less and a transmission characteristic for a wavelength of 900 nm, and is irradiated outside the scanning light source unit 2. As Figure 4 shown by the dotted line in (B) of, the laser (second light) with a wavelength of 950 nm emitted from the light emitting part LS4 is incident on the dichroic mirror R4 having a reflection characteristic for wavelengths of 950 nm or less and is reflected. After being reflected by the MEMS mirror 22, it passes through the dichroic mirror R1 having a reflection characteristic for wavelengths of 900 nm or less and a transmission characteristic for wavelengths of 950 nm or more, and is irradiated outside the scanning light source unit 2. The relationship between the light emitting part LS2 and the dichroic mirror R2 is the same. The laser with a wavelength of 900 nm emitted from the light emitting part LS2 is incident on the dichroic mirror R2 having a reflection characteristic for wavelengths of 900 nm or less and is reflected. After being reflected by the MEMS mirror 22, it passes through the dichroic mirror R3 having a reflection characteristic for wavelengths of 950 nm or less and a transmission characteristic for wavelengths of 900 nm or less, and is irradiated outside the scanning light source unit 2. The relationship between the light emitting unit LS3 and the dichroic mirror R3 is the same. The laser with a wavelength of 950nm emitted from the light emitting unit LS3 is incident on the dichroic mirror R3 having a reflection characteristic for wavelengths below 950nm and is reflected. After being reflected by the MEMS mirror 22, it passes through the dichroic mirror R2 having a reflection characteristic for wavelengths below 900nm and a transmission characteristic for wavelengths below 950nm, and is irradiated to the outside of the scanning light source unit 2. Figure 6 1 is a diagram showing an example of optical calculation of the measurement angle of view based on the optical scanning device of the above-mentioned embodiment. Each point shown in the figure represents a measurement point obtained using the light-emitting unit LS1, etc. With respect to the MEMS mirror 22, when the horizontal mechanical angle is set to ±8° and the vertical mechanical angle is set to ±5° and an optical calculation is performed, as shown in the figure, it can be seen that the measurement field angle can ensure ±60° in the horizontal direction and ±6° in the vertical direction. According to the calculation result, it can be seen that the vertical mechanical angle can be reduced and the measurement angle of view can be expanded compared with the past. In addition, in the figure, the measurement points based on LS1 are represented by black dots, the measurement points based on LS2 are represented by white dots, the measurement points based on LS3 are represented by black squares, and the measurement points based on LS4 are represented by white squares. In addition, for the measurement points based on each light-emitting unit, only the outer edge of the measurement range and the horizontal axis at the center of the measurement range and the measurement points along the horizontal axis are shown. According to the above-described embodiment, the measurement viewing angle in an optical scanning device or the like can be further expanded. In addition, the present disclosure is not limited to the contents of the above-mentioned embodiments, and can be implemented in various ways within the scope of the main purpose of the present disclosure. For example, in the above-mentioned embodiments, a dichroic mirror is shown as an example of an optical element for wavelength filtering, but a bandpass filter can be used as an optical element to replace the dichroic mirror or in combination with the dichroic mirror. For example, a bandpass filter with a transmission band of 25 nm that allows a wavelength of 900 nm ± 12.5 nm to pass through and reflects a wavelength region other than this, and a bandpass filter with a transmission band of 25 nm that allows a wavelength of 950 nm ± 12.5 nm to pass through and reflects a wavelength region other than this can be used. In the above-mentioned embodiment, the light source LS is configured so that the laser light emitted from the light source LS advances along the Y direction, but the configuration of the light source LS is not limited thereto, and for example, the substrate on which the light source LS is mounted may be configured to rotate along the X direction. In this case, the configuration of each dichroic mirror R1 and the like may be adjusted so that the laser light is incident along the normal direction (Z direction) of the MEMS mirror 22. In addition, in the above-described embodiment, the MEMS mirror 22 is configured such that the inclination of the MEMS mirror 22 in the initial state is 0° with respect to the Y-axis. However, the MEMS mirror 22 may be configured to be inclined by about up to 5° with respect to the Y-axis. In this case, it is only necessary to adjust the positions of the dichroic mirrors R1 and the like so that the laser light reflected by the MEMS mirror 22 with a swing angle of 0° travels parallel to the Z-direction. In addition, in the above-described embodiment, a structure using a dichroic mirror is described as an example of the optical element. However, the same effect can be obtained by using a reflective polarizer as the optical element. As the reflective polarizer described here, for example, a polarization beam splitter or a wire grid polarizer can be used. In this case, it is only necessary to dispose the reflective polarizer at the positions where the dichroic mirrors R1 and the like are disposed in the above-described embodiment. In addition, in this case, as each light-emitting unit LS1 and the like of the light source LS, a component that has a high degree of polarization and can substantially emit linearly polarized laser light is used. As an example, an end-face type laser diode that exhibits a degree of polarization of 90% or more in the s-wave component can be used. The basic structure of the scanning light source unit 2 of this modified embodiment 1 is the same as Figure 1 , Figure 2 the structure shown, and the difference is only that the dichroic mirrors R1 and the like are replaced with reflective polarizers, and each light-emitting unit LS1 and the like are replaced with components having a high degree of polarization. Therefore, the illustration of the basic structure is omitted. Figure 7 (A) of Figure 7 and Figure 8 (B) of are diagrams for more specifically explaining the relationship between each reflective polarizer and the trajectory of the laser light when the laser light passes through each reflective polarizer in the modified embodiment 1. Figure 8 is a diagram showing a combination example of the transmission / reflection characteristics of each reflective polarizer and the wavelength of each light-emitting unit in the modified embodiment 1. In this modified embodiment 1, for example, four combinations shown in Each of the reflective polarizers R11, R12, R13, and R14 is replaced with each of the dichroic mirrors R1, R2, R3, and R4 in the above-described embodiment. Each of the reflective polarizers R11, etc. is configured to have dimensions of approximately 3 mm in the short side, approximately 8 mm in the long side, and approximately 1 mm in thickness, for example. Each of the reflective polarizers R11, etc. is formed by laminating a dielectric multilayer film on a base layer such as a glass substrate in the case of a polarization beam splitter, and is formed by disposing a wire grid made of a metal such as aluminum on one surface of a glass substrate, etc. in the case of a wire grid type, for example. Moreover, in the same manner as in the above-described embodiment, a portion of approximately 3 mm to 4 mm along the long side direction is bonded and fixed inside the housing of the scanning light source unit 2 to an inclined surface provided at a position facing the MEMS mirror 22, and the remaining portion not fixed to the inclined surface is arranged to hang down from the inclined surface. In the case where the reflective polarizer R11, etc. is formed by a polarization beam splitter, the reflective polarizer R11, etc. is inclined so that the laser light emitted from each light emitting portion LS1, etc. of the light source LS is incident at approximately 45°. Bonding of the reflective polarizer R11, etc. can be performed using, for example, a photocurable resin or a thermosetting resin. A part of the irradiation region when scanning the laser by swinging the MEMS mirror 22 includes the position of the reflective polarizer R11, etc. in the same manner as in the above-described embodiment. The light reflected by the MEMS mirror 22 and incident on the reflective polarizer R11, etc. passes through the reflective polarizer R11, etc. and advances outward from the housing of the scanning light source unit 2. When passing through the inside of the reflective polarizer R11, etc., the laser light is refracted inside, so that the optical path is shifted relative to before incidence, but the degree of shift of this optical path is on the order of the thickness of the reflective polarizer R11, etc., so it has no influence on the ranging performance and can be corrected on the light receiving unit 3 side. Hereinafter, Figure 8 taking the combination of No.1 shown as an example, the operation of the scanning light source unit 2 of the first modified embodiment will be described, but the thinking method is the same for the combinations of No.2 to No.4. As Figure 7 shown by the dashed line in (A) of [], the s-wave laser light (first light) emitted from the light emitting portion LS1 is incident on the reflective polarizer R11 having a reflection characteristic for s-waves and is reflected. After being reflected by the MEMS mirror 22, it passes through the reflective polarizer R14 having a transmission characteristic for s-waves and is irradiated outside the scanning light source unit 2. In addition, as Figure 7 shown by the dashed line in (B) of [], the p-wave laser light (second light) emitted from the light emitting portion LS4 is incident on the reflective polarizer R14 having a reflection characteristic for p-waves and is reflected. After being reflected by the MEMS mirror 22, it passes through the reflective polarizer R11 having a transmission characteristic for p-waves and is irradiated outside the scanning light source unit 2. The same applies to the relationship between the light-emitting unit LS2 and the reflective polarizer R12. The s-wave laser emitted from the light-emitting unit LS2 is incident on the reflective polarizer R12 having a reflection characteristic for the s-wave and is reflected. After being reflected by the MEMS mirror 22, it passes through the reflective polarizer R13 having a transmission characteristic for the s-wave and is irradiated outside the scanning light source unit 2. The same applies to the relationship between the light-emitting unit LS3 and the reflective polarizer R13. The p-wave laser emitted from the light-emitting unit LS3 is incident on the reflective polarizer R13 having a reflection characteristic for the p-wave and is reflected. After being reflected by the MEMS mirror 22, it passes through the reflective polarizer R12 having a transmission characteristic for the p-wave and is irradiated outside the scanning light source unit 2. In addition, for the structure of the above-described modified embodiment 1, an optical scanning device of a modified embodiment 2 further combined with a quarter-wave plate can also be adopted. The quarter-wave plate mentioned here is a wavelength plate that can convert incident linearly polarized light into circularly polarized light or convert incident circularly polarized light into linearly polarized light. The structure of the scanning light source unit 2 of this modified embodiment 2 is in Figure 1 、 Figure 2 In the structure shown, the dichroic mirror R1, etc. are replaced with reflective polarizers, and each light-emitting unit LS1, etc. are replaced with components having a high degree of polarization (the structure of modified embodiment 1). As shown in the layout example inside the housing of the scanning light source unit in Figure 9 , the quarter-wave plates T (T1, T2, T3, T4) are arranged so as to be interposed between the reflective polarizer R and the MEMS mirror 22. In the illustrated example, the quarter-wave plates T are arranged in a manner of being adhesively fixed to the upper part inside the housing and hanging down. For example, an optical curable resin or a thermosetting resin can be used for the adhesion of the quarter-wave plates T. The reflective polarizer R in this modified embodiment 2 is configured to have a size of about 1 mm for the short side, about 8 mm for the long side, and about 1 mm for the thickness, and a portion of about 3 mm to 4 mm in the long side direction is adhesively fixed to the housing. The quarter-wave plates T are also configured to have the same size as the reflective polarizer R. The reason why the lateral widths (short sides) of the reflective polarizer R and the quarter-wave plates T are both small is that when deflected by the MEMS mirror 22, the incident angle of the laser when incident on the reflective polarizer R and the quarter-wave plates T changes, so that the polarization direction of the laser shifts and it is difficult to be polarized by the reflective polarizer R. Therefore, the incidence of the laser with a large incident angle like this on the reflective polarizer R, etc. is reduced. Figure 10 of (A) to Figure 10 of (D) are diagrams for more detailedly explaining the relationship between each reflective polarizer and the trajectory of the laser when the laser passes through each reflective polarizer in the modified embodiment 2. Figure 11This is a diagram showing a combination example of the transmission / reflection characteristics of each reflective polarizer and the wavelength of each light-emitting unit in Modified Embodiment 2. In this Modified Embodiment 2, for example, consider Figure 11 the two combinations shown. In this case, the light-emitting units LS1 to LS4 can be a type of light-emitting unit that all emit s-wave lasers, and the reflective polarizers R11 to R14 can be a type of polarizer that all have the characteristic of transmitting p-waves. Hereinafter, taking the combination of No.1 shown in Figure 11 as an example, the operation of the scanning light source unit 2 in this Modified Embodiment 2 will be described. However, the consideration method for the combination of No.2 is the same. As shown by the dashed line in (A) of Figure 10 , the s-wave laser emitted from the light-emitting unit LS1 is incident on the reflective polarizer R11 having a reflection characteristic for s-waves and is reflected. It passes through the quarter-wave plate T1 disposed between the MEMS mirror 22 and the reflective polarizer R11 and is converted into circularly polarized light, and is incident on the MEMS mirror 22. After being reflected by the MEMS mirror 22, it passes through the quarter-wave plate T4 and is converted into linearly polarized light of p-wave, passes through the reflective polarizer R14 having a transmission characteristic for p-waves, and is irradiated to the outside of the scanning light source unit 2. The quarter-wave plates T1 and T4 are arranged such that the light emitted from the light-emitting unit LS1 is incident substantially perpendicularly. In addition, in (A) of Figure 10 , for ease of explanation, the quarter-wave plates T2 and T3 are omitted, and the quarter-wave plates T2 and T3 are arranged at positions where they do not overlap on the optical path of the light emitted from the light-emitting unit LS1. In addition, as shown by the dashed line in (D) of Figure 10 , the s-wave laser emitted from the light-emitting unit LS4 is incident on the reflective polarizer R14 having a reflection characteristic for s-waves and is reflected. It passes through the quarter-wave plate T4 disposed between the MEMS mirror 22 and the reflective polarizer R14 and is converted into circularly polarized light and is incident on the MEMS mirror 22. After being reflected by the MEMS mirror 22, it passes through the quarter-wave plate T1 and is converted into linearly polarized light of p-wave, and is irradiated to the outside of the scanning light source unit 2 through the reflective polarizer R11 having a transmission characteristic for p-waves. The quarter-wave plates T1 and T4 are arranged such that the light emitted from the light-emitting unit LS4 is incident substantially perpendicularly. In addition, in (D) of Figure 10 , for ease of explanation, the quarter-wave plates T2 and T3 are omitted, and the quarter-wave plates T2 and T3 are arranged at positions where they do not overlap on the optical path of the light emitted from the light-emitting unit LS4. The relationship between the light-emitting unit LS2 and the reflective polarizer R12 is the same. As shown in Figure 10As shown by the dashed line in (B), the s-wave laser beam emitted from the light-emitting section LS2 is incident on the reflective polarizer R12 having reflection characteristics for the s-wave and is reflected. The beam passes through the quarter-wave plate T2 disposed between the MEMS mirror 22 and the reflective polarizer R12, is converted into circularly polarized light, and is incident on the MEMS mirror 22. After being reflected by the MEMS mirror 22, the beam passes through the quarter-wave plate T3, is converted into linearly polarized p-wave light, passes through the reflective polarizer R13 having transmission characteristics for the p-wave, and is irradiated outside the scanning light source section 2. The quarter-wave plates T2 and T3 are arranged such that the light emitted from the light-emitting section LS2 is incident thereon substantially perpendicularly. In addition, the quarter-wave plates T1 and T4 are arranged at positions where the optical paths of the light emitted from the light-emitting section LS2 do not overlap. The same applies to the relationship between the light-emitting section LS3 and the reflective polarizer R13. As Figure 10 shown by the dashed line in (C), the s-wave laser beam emitted from the light-emitting section LS3 is incident on the reflective polarizer R13 having reflection characteristics for the s-wave and is reflected. The beam passes through the quarter-wave plate T3 disposed between the MEMS mirror 22 and the reflective polarizer R13, is converted into circularly polarized light, and is incident on the MEMS mirror 22. After being reflected by the MEMS mirror 22, the beam passes through the quarter-wave plate T2, is converted into linearly polarized p-wave light, passes through the reflective polarizer R13 having transmission characteristics for the p-wave, and is irradiated outside the scanning light source section 2. The quarter-wave plates T2 and T3 are arranged such that the light emitted from the light-emitting section LS3 is incident thereon substantially perpendicularly. In addition, the quarter-wave plates T1 and T4 are arranged at positions where the optical paths of the light emitted from the light-emitting section LS3 do not overlap. In addition, in Modification Examples 1 and 2, a flat reflective polarizer has been described, but a cubic beam splitter may also be used. In this case, there is an advantage that the optical path length does not deviate. The present disclosure has the following features. (Supplementary Note 1) An optical scanning device for detecting an object by irradiating light and receiving the reflected light thereof, the optical scanning device comprising: a deflector; a light source having at least a first light-emitting section that emits first light and a second light-emitting section that emits second light having optical characteristics different from those of the first light; a first optical element configured to receive the first light emitted from the first light-emitting section and reflect the first light to make the first light incident on the deflector; and a second optical element configured to receive the second light emitted from the second light-emitting section and reflect the second light to make the second light incident on the deflector, The first optical element has an optical property of reflecting the first light and transmitting the second light. The second optical element has an optical property of reflecting the second light and transmitting the first light. (Supplementary Note 2) The optical scanning device according to Supplementary Note 1, The wavelengths of the first light and the second light as the optical property are different. The first optical element is a first dichroic mirror that reflects the first light and transmits the second light. The second optical element is a second dichroic mirror that reflects the second light and transmits the first light. (Supplementary Note 3) The optical scanning device according to Supplementary Note 1, The wavelengths of the first light and the second light as the optical property are different. The first optical element is a first band-pass filter that reflects the first light and transmits the second light. The second optical element is a second band-pass filter that reflects the second light and transmits the first light. (Supplementary Note 4) The optical scanning device according to Supplementary Note 2 or 3, The difference in wavelength between the first light and the second light is 50 nm or more. (Supplementary Note 5) The optical scanning device according to Supplementary Note 1, The polarization directions of the first light and the second light as the optical property are different. The first optical element is a first reflective polarizer that reflects the first light and transmits the second light. The second optical element is a second reflective polarizer that reflects the second light and transmits the first light. (Supplementary Note 6) The optical scanning device according to Supplementary Note 5, The difference in polarization direction between the first light and the second light is approximately 90°. (Supplementary Note 7) The optical scanning device according to Supplementary Note 5 or 6, The first light-emitting unit is a light-emitting unit that emits linearly polarized light as the first light. The second light-emitting unit is a light-emitting unit that emits linearly polarized light as the second light. (Supplementary Note 8) An optical scanning device for performing object detection by irradiating light and receiving its reflected light, wherein the optical scanning device includes: Deflector; A light source having at least a first light-emitting portion and a second light-emitting portion that emit first linearly polarized light; A first reflective polarizer configured to allow the first linearly polarized light emitted from the first light-emitting portion to be incident on the first reflective polarizer, and the first reflective polarizer reflects the first light from the first light-emitting portion and allows a second linearly polarized light whose polarization direction is approximately 90° different from that of the first light to pass through; A second reflective polarizer configured to allow the first linearly polarized light emitted from the second light-emitting portion to be incident on the second reflective polarizer, and the second reflective polarizer reflects the first linearly polarized light from the second light-emitting portion and allows a second linearly polarized light whose polarization direction is approximately 90° different from that of the first light to pass through; A first quarter-wave plate disposed between the first reflective polarizer and the deflector; and A second quarter-wave plate disposed between the second reflective polarizer and the deflector, The first linearly polarized light reflected by the first reflective polarizer passes through the first quarter-wave plate and is converted into circularly polarized light, is incident on the deflector, is reflected by the deflector, then is incident on and passes through the second quarter-wave plate and is converted into the second linearly polarized light, and is incident on and passes through the second reflective polarizer, The first linearly polarized light reflected by the second reflective polarizer passes through the second quarter-wave plate and is converted into circularly polarized light, is incident on the deflector, is reflected by the deflector, then is incident on and passes through the first quarter-wave plate and is converted into the second linearly polarized light, and is incident on and passes through the first reflective polarizer. (Supplementary Note 9) An object detection device, comprising: The optical scanning device according to any one of Supplementary Notes 1 to 8; A light-receiving portion that detects the reflected light of the irradiation light emitted from the optical scanning device and generates a light-receiving signal corresponding to the intensity of the reflected light; and A control portion that controls the operation of the optical scanning device and generates point cloud information based on the light-receiving signal.

Claims

1. An optical scanning device, which is a device for object detection by irradiating light and receiving its reflected light, wherein, The light scanning device includes: A deflector; A light source having at least a first light emitting portion that emits first light and a second light emitting portion that emits second light having optical characteristics different from those of the first light; A first optical element configured to cause the first light emitted from the first light emitting portion to be incident on the first optical element, and the first optical element reflects the first light and causes the first light to be incident on the deflector; And A second optical element configured to cause the second light emitted from the second light emitting portion to be incident on the second optical element, and the second optical element reflects the second light and causes the second light to be incident on the deflector, The first optical element has an optical characteristic of reflecting the first light and transmitting the second light, The second optical element has an optical characteristic of reflecting the second light and transmitting the first light.

2. The light scanning device according to claim 1, wherein The wavelengths of the first light and the second light as the optical characteristics are different, The first optical element is a first dichroic mirror that reflects the first light and transmits the second light, The second optical element is a second dichroic mirror that reflects the second light and transmits the first light.

3. The light scanning device according to claim 1, wherein The wavelengths of the first light and the second light as the optical characteristics are different, The first optical element is a first band-pass filter that reflects the first light and transmits the second light, The second optical element is a second band-pass filter that reflects the second light and transmits the first light.

4. The light scanning device according to claim 2 or 3, wherein The difference in wavelength between the first light and the second light is 50 nm or more.

5. The light scanning device according to claim 1, wherein The polarization directions of the first light and the second light as the optical characteristics are different, The first optical element is a first reflective polarizer that reflects the first light and transmits the second light, The second optical element is a second reflective polarizer that reflects the second light and transmits the first light.

6. The light scanning device according to claim 5, wherein The difference in polarization direction between the first light and the second light is approximately 90°.

7. The light scanning device according to claim 5, wherein The first light emitting portion is a light emitting portion that emits linearly polarized light as the first light, The second light emitting portion is a light emitting portion that emits linearly polarized light as the second light.

8. An optical scanning device, which is a device for object detection by irradiating light and receiving its reflected light, wherein, The light scanning device includes: A deflector; A light source having at least a first light emitting portion that emits first linearly polarized light and a second light emitting portion; A first reflective polarizer configured to cause the first linearly polarized light emitted from the first light emitting portion to be incident on the first reflective polarizer, and the first reflective polarizer reflects the first linearly polarized light from the first light emitting portion and transmits second linearly polarized light whose polarization direction differs from that of the first linearly polarized light by approximately 90°; A second reflective polarizer configured to receive the first linearly polarized light emitted from the second light-emitting unit, and the second reflective polarizer reflects the first linearly polarized light from the second light-emitting unit and transmits the second linearly polarized light whose polarization direction is approximately 90° different from that of the first linearly polarized light; A first quarter-wave plate disposed between the first reflective polarizer and the deflector; And A second quarter-wave plate disposed between the second reflective polarizer and the deflector, The first linearly polarized light reflected by the first reflective polarizer passes through the first quarter-wave plate and is converted into circularly polarized light, enters the deflector, is reflected by the deflector, then enters and passes through the second quarter-wave plate and is converted into the second linearly polarized light, and enters and passes through the second reflective polarizer, The first linearly polarized light reflected by the second reflective polarizer passes through the second quarter-wave plate and is converted into circularly polarized light, enters the deflector, is reflected by the deflector, then enters and passes through the first quarter-wave plate and is converted into the second linearly polarized light, and enters and passes through the first reflective polarizer.

9. An object detection device, wherein, The object detection device includes: The light scanning device according to claim 1 or 8; A light receiving unit that detects the reflected light of the irradiation light emitted from the light scanning device and generates a light receiving signal corresponding to the intensity of the reflected light; and A control unit that controls the operation of the light scanning device and generates point cloud information based on the light receiving signal.

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