JP2020046339A - Light projection device, light projection/reception device, and ranging device - Google Patents

Abstract

To provide a light projection/reception device capable of accurately projecting and receiving light by projecting light with reduced intensity irregularity, and to provide a ranging device capable of accurately measuring distance.SOLUTION: A light projection/reception device provided herein comprises: a light source 11 configured to emit light having a cross-section with a long axis and a short axis; a light shield 13 for blocking light in end portions in a long-axis direction; and a photosensitive element 14 having a light receiving surface comprised of a plurality of photosensitive segments arrayed along a direction corresponding to the long-axis direction and configured to receive reflection light reflected by an object.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device that emits light, a light emitting and receiving device that emits and receives light, and a distance measuring device that performs optical distance measurement.

  2. Description of the Related Art A ranging device that irradiates a target with light and detects light reflected by the target to measure a distance to the target has been known. In addition, a scanning distance measuring device that measures a distance to a plurality of objects by performing optical scanning is known. For example, Patent Literature 1 discloses an optical radar device including a light projecting unit, a light receiving unit, and a distance measuring unit.

JP 2007-85832 A

  For example, a distance measuring device includes a light emitting unit that emits a laser beam for distance measurement and a light receiving unit that receives light reflected by an object. In addition, as a configuration of the light emitting unit and the light receiving unit, for example, a configuration in which the light emitting unit emits a laser beam having a predetermined elongated beam shape, and the light receiving unit receives reflected light from an object by a plurality of light receiving elements. Is mentioned. In this case, it is possible to collectively transmit and receive light to and from a plurality of target regions (a plurality of target objects and a plurality of surface regions of the target object).

  Here, considering that accurate distance measurement is performed on each of the plurality of target regions, for example, it is preferable that light having a uniform intensity is projected on each of the plurality of target regions. That is, it is preferable that intensity unevenness is small in the beam of the projected light.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a light projecting device capable of projecting light with reduced intensity unevenness. Further, the present invention provides a light emitting and receiving device capable of performing accurate light emitting and receiving by projecting light with reduced intensity unevenness and a distance measuring device capable of performing accurate distance measuring. Is one of the objectives.

  The invention according to claim 1 includes a light source that emits light having a cross-sectional shape having a longitudinal direction and a lateral direction, and a light-shielding portion that shields an end in the longitudinal direction of the light.

  According to a tenth aspect of the present invention, there is provided the light projecting device according to the first aspect, wherein the light passing through the light-shielding portion is projected toward the target and receives the reflected light reflected by the target, and receives the light. A light-receiving element having a light-receiving surface composed of a plurality of light-receiving segments arranged along a direction corresponding to the direction.

  According to a thirteenth aspect of the present invention, there is provided the light emitting and receiving device according to the tenth aspect, and a distance measuring unit that measures a distance to an object based on a result of receiving the reflected light by the light receiving element. Features.

FIG. 1 is a diagram illustrating an entire configuration of a distance measuring apparatus according to a first embodiment. FIG. 3 is a diagram illustrating a light emitting surface of a light source in the distance measuring apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example of a light shielding unit in the distance measuring apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a light receiving surface of a light receiving element in the distance measuring apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of a light receiving optical system in the distance measuring apparatus according to the first embodiment.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a schematic layout diagram of the distance measuring apparatus 10 according to the first embodiment. The distance measuring device 10 is a scanning type distance measuring device that performs optical scanning of a predetermined region (hereinafter, referred to as a scanning region) R0 and measures a distance to an object OB existing in the scanning region R0. The distance measuring device 10 will be described with reference to FIG. FIG. 1 schematically shows the scanning region R0 and the object OB.

  First, the distance measuring apparatus 10 includes a light source 11 that generates and emits pulsed light (hereinafter, referred to as primary light) L1. In this embodiment, the light source 11 generates laser light having a peak wavelength in the infrared region as the primary light L1, and emits the laser light intermittently. In this embodiment, a laser beam having a linear cross-sectional shape is emitted as the primary light L1.

  The distance measuring device 10 includes an imaging optical system 12 that forms an image of the primary light L1 (an intermediate image), that is, a cross-sectional shape (an image indicating a beam shape) of the primary light L1. The imaging optical system 12 includes, for example, a relay lens.

  The distance measuring device 10 has a light blocking unit 13 that blocks a part of the primary light L1. In the present embodiment, the light shielding unit 13 is disposed at a position (imaging point) where the image of the primary light L1 is formed. The primary light L1 that has passed through the light shielding unit 13 is output from the light shielding unit 13 as a secondary light L2.

  In the present embodiment, the light shielding unit 13 is a light shielding plate having an opening. In the present embodiment, a part of the primary light L1 is shielded by the light shielding unit 13. The primary light L1 that is not shielded by the light-shielding portion 13 passes through the opening of the light-shielding portion 13 as secondary light (hereinafter sometimes referred to as light-projected light) L2. In the present embodiment, the light shielding unit 13 is a reflecting plate having reflectivity for the primary light L1.

  The distance measuring device 10 includes a light receiving element (first light receiving element) 14 that receives the reflected primary light L1R, which is a part of the primary light L1 reflected by the light shielding unit 13. For example, the light receiving element 14 includes at least one detection element that detects the reflected primary light L1R.

  The distance measuring device 10 has a light projecting optical system 15 that projects the secondary light L2, that is, the primary light L1 that has passed through the light shielding unit 13. The light projecting optical system 15 includes, for example, at least one lens.

  The distance measuring apparatus 10 includes a deflecting element (first deflecting element) 16 that deflects the secondary light L2 in a variable direction and projects the secondary light L2 as tertiary light (hereinafter sometimes referred to as scanning light) L3. The deflecting element 16 performs a periodic operation to periodically change the deflecting direction of the secondary light L2. The deflection element 16 emits the secondary light L2 while bending the traveling direction thereof, and periodically changes the bending direction. The secondary light L2 deflected by the deflecting element 16 is emitted as a tertiary light L3 toward the scanning region R0.

  In this embodiment, the deflecting element 16 has at least one turning mirror 16A that turns around the turning axis AY and reflects the secondary light L2. For example, the deflecting element 16 includes a polygon mirror. In the present embodiment, the deflecting element 16 periodically changes the reflection direction of the secondary light L2 by reflecting the secondary light L2 while the rotating mirror 16A rotates. That is, in the present embodiment, the tertiary light L3 is the secondary light L2 reflected by the turning mirror 16A of the deflecting element 16.

  The scanning region R0 is a virtual three-dimensional space where the tertiary light L3, which is the secondary light L2 that has passed through the deflecting element 16, is projected. In FIG. 1, the outer edge of the scanning region R0 is schematically shown by a broken line.

  In the present embodiment, the light source 11 emits, as the primary light L1, laser light having a linear cross-sectional shape extending along the axial direction of the rotation axis AY of the rotation mirror 16A.

  Therefore, for example, the scanning region R0 includes a direction range in the height direction along the longitudinal direction (hereinafter, referred to as a first direction) D1 in the cross section of the secondary light L2, and the deflection of the secondary light L2 by the deflection element 16. A direction range in the width direction along a direction (hereinafter, referred to as a second direction) D2 corresponding to the variable range of the direction, and a range in the distance direction (ie, a depth range) in which the tertiary light L3 can maintain a predetermined intensity. , Can be defined as a conical space having

  When a virtual plane separated by a predetermined distance from the deflecting element 16 in the scanning area R0 is defined as the scanning plane R1, the scanning plane R1 has a two-dimensional shape that extends along the first and second directions D1 and D2. Area can be defined. The tertiary light L3 is emitted toward the scanning region R0 so as to scan the scanning surface R1. In the present embodiment, the first direction D1 corresponds to the main scanning direction, and the second direction D2 corresponds to the sub-scanning direction.

  In addition, as shown in FIG. 1, when the target object OB (that is, an object or a substance having reflectivity or scattering property with respect to the secondary light L2) exists in the scanning region R0, the tertiary light L3 emits the target object OB. Reflected or scattered by Part of the tertiary light L3 reflected by the object OB is a quaternary light (hereinafter, sometimes referred to as reflected light) L4, and the tertiary light L3 and the tertiary light L3 have substantially the same optical path as the tertiary light L3. Travels in the opposite direction and returns to the deflecting element 16.

  The distance measuring device 10 is a light common to the secondary light L2 and the quaternary light L4 on the optical path of the quaternary light L4, in this embodiment, between the deflecting element 16 and the light projecting optical system 15 (the light shielding unit 13). A deflecting element (second deflecting element) 17 is provided on the road and deflects the fourth-order light L4. For example, the deflecting element 17 is a light separating element that separates the secondary light L2 and the quaternary light L4 by transmitting the secondary light L2 and reflecting the quaternary light L4. In the present embodiment, the deflecting element 17 is a beam splitter. is there.

  In other words, in the present embodiment, the deflecting element 16 is a movable deflecting element for scanning that operates to deflect the secondary light L2 in a variable direction. On the other hand, the deflection element 17 is a fixed deflection element.

  The distance measuring device 10 has a light receiving optical system 18 that receives the quaternary light L4 deflected by the deflecting element 17. The light receiving optical system 18 shapes the fourth order light L4 while condensing it. The light receiving optical system 18 includes, for example, at least one lens.

  Further, the distance measuring device 10 includes a light receiving element (second light receiving element) 19 that receives the fourth-order light L4. The light receiving element 19 is arranged, for example, at the focal position of the quaternary light L4 collected by the light receiving optical system 18. For example, the light receiving element 19 has at least one detection element that detects the fourth-order light L4 and generates an electric signal corresponding to the fourth-order light.

  The light receiving element 19 generates the electric signal as a detection result (light reception result) of the fourth light L4. That is, the distance measuring device 10 generates the electric signal generated by the light receiving element 19 as a scanning result of the scanning region R0.

  The distance measuring device 10 includes a control unit 20 that drives and controls the light source 11, the light receiving element 14, the deflection element 16, and the light receiving element 19. For example, in the present embodiment, the control unit 20 includes a light source control unit 21 that drives and controls the light source 11 and a monitoring unit 22 that receives part of the primary light L1 and monitors the primary light L1. And Further, the control unit 20 drives the light receiving element 14, the deflection element 16, and the light receiving element 19.

  Further, the control unit includes a distance measuring unit 23 that measures a distance to the object OB based on a result of receiving the fourth-order light L4 by the light receiving element 19. In the present embodiment, the distance measuring unit 23 detects a pulse indicating the fourth-order light L4 from the electric signal. Further, the distance measurement unit 23 uses the time-of-flight method based on the time difference between the timing of projecting the tertiary light L3 and the timing of receiving the quaternary light L4 to reach the object OB (or a partial surface area thereof). Measure the distance. Further, the distance measuring unit 23 generates data (distance measurement data) indicating the measured distance information.

  Further, in the present embodiment, the distance measuring unit 23 distinguishes the scanning area R0 (scanning surface R1) into a plurality of distance measuring points (scanning points), and calculates a distance measurement result (distance) of each of the plurality of distance measuring points. The image (distance measurement image) of the scanning region R0 indicating the value (pixel value) as a pixel is generated. In the present embodiment, the distance measurement unit 23 associates the distance measurement points with the information indicating the displacement of the rotating mirror 16A, and generates image data indicating a two-dimensional map or a three-dimensional map of the scanning region R0.

  Further, the distance measurement unit 23 sets, for example, a change cycle of the projection direction of the tertiary light L3, that is, a scan cycle that is a cycle of scanning the scan region R0 as a distance measurement image generation cycle, and one scan cycle for each scan cycle. Generate a ranging image.

  Note that the scanning cycle is, for example, a period until a predetermined displacement of the rotating mirror 16A returns to the predetermined displacement again thereafter when the distance measuring device 10 periodically performs optical scanning on the scanning region R0. Say. Further, the distance measurement unit 23 may include a display unit (not shown) that displays the generated plurality of distance measurement images as a moving image in chronological order.

  FIG. 2 is a diagram schematically showing a light emitting surface 11A of the light source 11. As shown in FIG. In this embodiment, the light source 11 has three laser bars E1, E2 and E3, each extending in the first direction D1, and these laser bars E1 to E3 are in the second direction D2 (that is, the laser bars E1 to E3). E3).

  Each of the laser bars E1 to E3 emits a linear or elliptical laser beam having a cross-sectional shape (beam shape) having the first direction D1 as a longitudinal direction and the second direction D2 as a lateral direction. Further, each of the laser bars E1 to E3 is arranged along the second direction D2 and emits a laser beam along an optical axis extending in parallel with each other.

  The light source 11 emits the entirety of the laser beams emitted from the laser bars E1 to E3 as primary light L1. In the present embodiment, the entire primary light L1 has a linear cross-sectional shape having the first direction D1 and the second direction D2 as the longitudinal direction and the lateral direction, respectively.

  FIG. 3 is a diagram schematically illustrating a configuration of the light shielding unit 13 and a cross-sectional shape of the secondary light L2 generated by the light shielding unit 13. As shown in FIG. 3, in the present embodiment, the primary light L1 emitted from the light source 11 has a cross-sectional shape having a first direction D1 and a second direction D2 as a longitudinal direction and a lateral direction, respectively. Of the primary laser beams L11, L12, and L13. For example, the primary laser beams L11, L12, and L13 correspond to the laser beams emitted from the laser bars E1, E2, and E3, respectively.

  That is, in this embodiment, the light source 11 has a plurality of primary laser beams L11, L12, and L13 each having a cross-sectional shape having a longitudinal direction and a lateral direction, and being arranged along the lateral direction. Is emitted.

  Further, in the present embodiment, the light shielding unit 13 is arranged at a position where the image (intermediate image) L1P of the primary light L1 of the light source 11 on the light emission surface 11A of the light source 11 is formed by the imaging optical system 12. FIG. 3 schematically illustrates each of the images of the primary laser beams L11 to L13 constituting the image L1P on the light emitting surface.

  In addition, the primary laser beams L11, L12, and L13 that have passed through the light shielding unit 13 pass through the light shielding unit 13 as secondary laser lights L21, L22, and L23, respectively. The secondary light L2 includes these three secondary laser lights L21, L22, and L23. Further, the entire secondary light L2 has a linear cross-sectional shape having the first direction D1 and the second direction D2 as the longitudinal direction and the lateral direction, respectively.

  Further, as shown in FIG. 3, in the present embodiment, the light shielding unit 13 is configured and arranged so as to shield each end of the primary laser beams L11 to L13. Further, in the present embodiment, the light-shielding portions 13 are arranged such that the lengths of the secondary laser beams L21 to L23, that is, the primary laser beams L11 to L13 passing through the light-shielding portions 13 are aligned along the first direction D1. Each end of the primary laser beams L11 to L13 is shielded.

  Therefore, each of the secondary laser beams L21 to L23 has a cross-sectional shape in which the length in the longitudinal direction and the positions of the ends in the longitudinal direction are aligned. Therefore, the secondary light L2 is projected as light having a rectangular outer shape with a clear outer edge in the longitudinal direction.

  Here, the primary light L1 and the secondary light L2 will be described. For example, when trying to increase the distance that the distance measuring device 10 can measure, it is conceivable to increase the intensity of the light projected as the tertiary light L3. In consideration of emitting the high-intensity primary light L1, it is conceivable to use a high-output light source as the light source 11.

  In consideration of obtaining the quaternary light L4 from a plurality of regions in the scanning region R0 collectively, it is conceivable to use a laser element in which the laser bars E1 to E3 are stacked as the light source 11 as described above. Can be Thereby, for example, it is possible to obtain a high-output linear tertiary light L3 while suppressing an increase in the size or complexity of the optical system.

  On the other hand, in a stacked laser element as the light source 11, the shape of the light emitting surface of the laser bars E1 to E3 is slightly different. Specifically, for example, as shown in FIG. 2, the lengths of the laser bars E1 to E3 in the longitudinal direction (the lengths of the bars) are slightly different. For example, the laser bar E1 has the longest bar length, and the laser bar E3 has the longest bar length.

  In this case, as shown in FIG. 3, among the primary laser beams L11 to L13, the primary laser beam L11 has the shortest beam shape, and the primary laser beam L13 has the longest beam shape. The primary light L1 composed of the primary laser lights L11 to L13 has different intensities as a whole between the center and the end in the first direction D1.

  Therefore, for example, the light corresponding to the center of the primary light L1 in the first direction D1 has sufficient intensity, while the light corresponding to the end of the primary light L1 in the first direction D1 is sufficient. May not have strength. Therefore, if the primary light L1 is projected as it is as the tertiary light L3, a region where the sufficient amount of the tertiary light L3 is irradiated in the scanning region R0 and the region where the tertiary light L3 is irradiated with the sufficient light are irradiated. There is a case where there is a region that is not performed. Therefore, unevenness may occur in the distance measurement accuracy in the scanning area R0, or an area where the distance that can be measured may be shorter than other areas may occur.

  On the other hand, in the present embodiment, the light shielding unit 13 that shields the end of each of the primary laser beams L11 to L13 in the first direction D1 is arranged. Accordingly, the lengths of the secondary laser beams L21 to L23 in the first direction D1 are uniform, and the intensity of the secondary light L2 as a whole along the first direction D1 is made uniform. Therefore, the light amount of the tertiary light L3 projected on the scanning region R0 is made uniform, and scanning and distance measurement with stable accuracy can be performed over the entire scanning region R0.

  In this embodiment, only a part of the primary light L1 is projected as the secondary light L2. That is, the secondary light L2 has a smaller intensity than the primary light L1. On the other hand, the light source control unit 21 of the control unit 20 controls the intensity of the primary light L1, that is, the output of the light source 11, so that the secondary light L2 has a designed light amount. That is, the light source 11 emits the primary light L1 with an output based on the light amount of the secondary light L2, which is the primary light L1 that has passed through the light shielding unit 13.

  More specifically, for example, the light source 11 emits a laser beam as the primary light L1. In addition, it is assumed that the distance measuring device 10 measures a distance using various spaces as a scanning region R0, for example, being mounted on a moving body such as a vehicle. In this case, it is assumed that a human is irradiated with laser light. Therefore, it is necessary to consider the intensity that is the upper limit of the laser light that can be projected as the tertiary light L3.

  In the present embodiment, the light source control unit 21 controls the output of the light source 11 for setting the light amount of the tertiary light L3 based on the light amount of the secondary light L2. In other words, the output of the light source 11 is controlled in consideration of the secondary light L2 having a light amount closer to the light amount of the tertiary light L3 than the primary light L1. Therefore, the tertiary light L3 can be emitted while appropriately adjusting the output while satisfying the output limitation of the laser light.

  Further, in the present embodiment, the light shielding portion 13 has reflectivity to the primary light L1. Further, a light receiving element 14 for receiving the reflected primary light L1R reflected by the light shielding unit 13 is provided. The monitoring unit 22 monitors the primary light L1 based on the result of receiving the reflected primary light L1R by the light receiving element 14.

  That is, when the light shielding unit 13 reflects a part of the primary light L <b> 1, the reflected primary light L <b> 1 can be used for monitoring the light source 11. Therefore, the operation monitoring of the light source 11 can be performed only by providing the light receiving element 14. In other words, when the light shielding unit 13 has reflectivity for the primary light L1, the primary light L1 reflected by the light shielding unit 13 is received and the primary light L1 (for example, the light amount of the primary light L1) is received. By providing the monitoring unit 22 for monitoring, the ranging device 10 can have a monitoring function with a simple configuration.

  FIG. 4 is a diagram schematically showing the light receiving surface 19R of the light receiving element 19. As shown in FIG. As shown in FIG. 4, the light receiving element 19 has a light receiving surface 19R including a plurality of light receiving segments 19A arranged along the first direction D1. In this embodiment, the light receiving element 19 is a line sensor in which each of the light receiving segments 19A is arranged in one line and has a linear light receiving surface 19R.

  In the present embodiment, each of the light receiving segments 19A performs a light receiving operation of the fourth order light L4 independently of each other. Each of the light receiving segments 19A has at least one photoelectric conversion element.

  FIG. 5 is a diagram illustrating a configuration example of the light receiving optical system 18 and the light receiving element 19. In the present embodiment, the light receiving optical system 18 condenses the fourth order light L4 such that the fourth order light L4 is incident on the entire light receiving surface 19R of the light receiving element 19 in the first direction D1. Therefore, the fourth-order light L4 is incident on each of the light receiving segments 19A. Then, an electric signal corresponding to the portion of the fourth-order light L4 received for each light receiving segment 19A is generated by each of the light receiving segments 19A.

  In other words, the light receiving optical system 18 maximizes the light receiving element 19 according to the beam shape of the primary light L1 that has passed through the light shielding unit 13 (in this embodiment, the length of the beam in the first direction D1). The light-gathering characteristics are adjusted so as to operate. Therefore, an accurate light receiving operation can be performed in all of the light receiving segments 19A.

  As described above, in the present embodiment, the distance measuring device 10 emits the first light L1 in the first direction with respect to the light source 11 that emits the primary light L1 having a cross-sectional shape whose longitudinal direction is the first direction D1. A light-shielding portion 13 that shields the end of D1 is provided. Therefore, the light at the end of the primary light L1, that is, the light with low intensity in the primary light L1, is blocked. Therefore, the secondary light L2 with reduced intensity unevenness can be projected, and accurate scanning and distance measurement can be performed.

  In the present embodiment, a case has been described in which the light source 11 includes a stacked laser element in which a plurality of laser bars E1 to E3 are stacked. However, the configuration of the light source 11 is not limited to this.

  For example, the light source 11 emits a plurality of light beams (for example, primary laser beams L11 to L13) each having a cross-sectional shape having a longitudinal direction (for example, a first direction D1) and a lateral direction (for example, a second direction D2). What is necessary is just to be comprised so that. For example, the light source 11 may include various light emitting elements, and may have an optical system for shaping light emitted from the light emitting elements as described above.

  Further, the light source 11 is not limited to the case where the light source 11 is configured to emit a plurality of primary laser lights L11 to L13. For example, the light source 11 may be configured to emit only one primary laser light (for example, only the primary laser light L12) as the primary light L1.

  Specifically, when the primary light L1 having a linear cross-sectional shape like the primary light L1 is projected, the edge of the primary light L1 may have a smaller intensity than the center. In addition, the intensity of the end of the primary light L1 may not be stable as compared with the intensity of the center. Thus, the characteristics of the end of the primary light L1 may be more unstable than the characteristics of the center of the primary light L1. Therefore, it is preferable to project only the central portion of the primary light L1. Therefore, by shielding the end of the primary light L1 emitted from the light source 11 in the first direction D1, the secondary light L2 having a stable intensity can be emitted.

  Further, in the present embodiment, the case where the light shielding unit 13 is configured to shield each of the ends of the primary laser lights L11 to L13 has been described. However, the configuration of the light shielding unit 13 is not limited to this. The light shielding unit 13 only needs to be configured to shield at least one end of the primary laser beams L11 to L13.

  When the light source 11 emits the primary light L1 composed of a plurality of lights (for example, primary laser lights L11 to L13), as described above, the light shielding unit 13 passes through the light shielding unit 13 (the light is shielded by the light shielding unit 13). It is preferable that an end of at least one of the plurality of lights in the first direction D1 is shielded so that the lengths of the light in the first direction D1 are uniform.

  Further, the light-shielding portion 13 is not limited to a case where the light passing through the light-shielding portion 13 is configured to have the same length in the first direction D1. The light-shielding unit 13 is configured to output at least one light (for example, only the primary laser light L13 or the primary laser light L12 and the primary laser light L13) protruding from the other light in the first direction D1 among the plurality of lights emitted from the light source 11. (L13 only) as long as it is configured to shield the end in the first direction D1. Even in this case, it can be expected that the intensity unevenness of the primary light L1 is reduced.

  Further, in the present embodiment, the case where the light shielding unit 13 has reflectivity to the primary light L1 has been described. However, it is only necessary that the light shielding unit 13 be configured to shield (not project) the end of the primary light L1 in the first direction D1. For example, the light shielding unit 13 may have an absorptivity to the primary light L1.

  In the case where the light-shielding portion 13 does not reflect the primary light L1, the light-receiving element 14 may not be provided. In this case, the light source 11 may be monitored by other general means without using the light shielding unit 13.

  Further, in the present embodiment, the case where the light shielding portion 13 is formed of a light shielding plate having an opening on the optical path of a part (the central portion in the present embodiment) of the primary light L1 has been described. However, the configuration of the light shielding unit 13 is not limited to this. For example, the light-shielding part 13 may be a light-transmitting plate having a transmission part for transmitting the primary light L1 on the optical path in the central part of the primary light L1, and other parts having light-shielding characteristics. Further, the light shielding unit 13 may have a plurality of light shielding plates.

  Further, the light shielding unit 13 may be configured to shield only one of the ends of the primary light L1 in the first direction D1. For example, depending on the beam shape relationship between the primary laser beams L11 to L13, the primary laser beam L13 protrudes most at one end in the first direction D1 and primary laser light at the other end. L12 may protrude most. In this case, the light shielding unit 13 is configured to shield the end of the primary laser light L13 at the one end and shield the end of the primary laser light L12 at the other end. You may.

  Further, in the present embodiment, an imaging optical system 12 that forms an image L1P of the primary light L1 is provided, and the light shielding unit 13 is disposed at a position where the image L1P of the primary light L1 is formed. The case has been described. However, the position of the light shielding unit 13 is not limited to this.

  For example, the distance measuring device 10 may not have the imaging optical system 12. Further, the light-shielding portion 13 may be disposed very near the light emission surface 11A of the light source 11. That is, the primary light L <b> 1 may be configured so that a part of the primary light L <b> 1 is shielded by the light shielding unit 13 immediately after being emitted from the light source 11.

  Considering that the end of the primary light L1 is surely shielded, the light-shielding part 13 is arranged at the image-forming position of the image L1P of the light emitting surface 11A of the light source 11 after the image-forming optical system 12 is arranged. Is preferred. Specifically, when the light shielding portion 13 is arranged at a position other than the image forming position of the image L1P, the end of the primary light L1 passing through the light shielding portion 13 may not be reliably shielded.

  In other words, the distance measuring device 10 is provided on the optical path of the primary light L1 between the light source 11 and the light shielding unit 13, and forms an image forming optical system 12 that forms an image L1P of the light emitting surface 11A of the light source 11. It is preferable to have Further, it is preferable that the light shielding unit 13 is arranged at a position where the image L1P is formed.

  In the present embodiment, the case has been described in which the light source control unit 21 of the control unit 20 controls the light source 11 so as to emit the primary light L1 having an intensity corresponding to the amount of the secondary light L2. However, the light source 11 only needs to be configured to emit the primary light L1 in a predetermined manner or to adjust the emission manner of the primary light L1.

  As described above, in the present embodiment, the distance measuring device 10 emits light (primary light L1) having a cross-sectional shape having a longitudinal direction (first direction D1) and a lateral direction (second direction D2). Light source 11, a light-shielding portion 13 for shielding the end portion of the light in the longitudinal direction, and a light (secondary light L2) passing through the light-shielding portion 13 deflectable in a variable direction to the object OB in the scanning region R0. And a deflecting element 16 for projecting light.

  Further, the distance measuring device 10 receives reflected light (quaternary light L4), which is light (tertiary light L3) reflected by the object OB, and arranges a plurality of light beams arranged along a direction corresponding to the longitudinal direction. And a distance measuring unit 23 that measures the distance to the object OB based on the result of receiving the reflected light by the light receiving element 19. Therefore, it is possible to provide the distance measuring apparatus 10 capable of performing accurate distance measurement by projecting light with reduced intensity unevenness.

  The result of receiving the fourth-order light L4 by the light receiving element 19 can be effectively used for purposes other than distance measurement, for example, for detecting the object OB. Therefore, the distance measuring device 10 does not need to include the distance measuring unit 23. In this case, for example, the light source 11, the light shielding unit 13, the deflecting element 16, and the light receiving element 19 in the distance measuring device 10 function as a scanning device, that is, a scanning type light emitting and receiving device.

  Further, the distance measuring device 10 may not have the deflection element 16 in addition to the distance measuring unit 23. In this case, for example, the light source 11, the light shielding unit 13, and the light receiving element 19 in the distance measuring device 10 function as a non-scanning type light emitting and receiving device. Even in this case, for example, light emission and reception using light of uniform intensity can be performed. That is, the present invention can also be implemented as a light emitting and receiving device capable of performing accurate light emitting and receiving by projecting light with reduced intensity unevenness.

  Further, the distance measuring device 10 may not have the light receiving element 19. In this case, the light source 11 and the light shielding unit 13 function as a light emitting device. In this case, for example, light of uniform intensity can be emitted. That is, the present invention can also be implemented as a light projecting device capable of projecting light with reduced intensity unevenness.

  As described above, for example, the light projecting device according to the present embodiment emits light (primary light L1) having a cross-sectional shape having a longitudinal direction (first direction D1) and a lateral direction (second direction D2). A light source 11 and a light shielding unit 13 for shielding the end of the light in the longitudinal direction. Therefore, it is possible to emit light with reduced intensity unevenness.

Reference Signs List 10 distance measuring device 11 light source 13 light shielding unit

Claims (13)

A light source that emits light having a cross-sectional shape having a longitudinal direction and a lateral direction in a cross section perpendicular to the traveling direction,
A light-shielding portion that shields the end of the light in the longitudinal direction. The light source has a cross-sectional shape each having a longitudinal direction and a transverse direction and emits a plurality of lights arranged along the transverse direction,
The light projection device according to claim 1, wherein the light blocking unit blocks at least one end of the plurality of lights in the longitudinal direction.   3. The light projection device according to claim 2, wherein the light shielding unit blocks an end in the longitudinal direction of at least one light of the plurality of lights protruding from other light in the longitudinal direction. 4. apparatus.   The light-shielding portion shields an end of the at least one light in the longitudinal direction such that the lengths of the plurality of lights passing through the light-shielding portion along the longitudinal direction are aligned. The light emitting device according to claim 2. An imaging optical system is provided on an optical path of the light between the light source and the light shielding unit, and forms an image of a light emission surface of the light source,
The light projection device according to any one of claims 1 to 4, wherein the light shielding unit is disposed at a position where the image is formed.   The light emitting device according to claim 1, wherein the light source emits the light with an output based on a light amount of the light passing through the light blocking unit.   The light projection device according to claim 1, wherein the light blocking unit has reflectivity for the light.   The light projection device according to claim 7, further comprising a monitoring unit that receives the light reflected by the light blocking unit and monitors the light.   9. The light projection device according to claim 1, wherein the light source includes a laser element in which a plurality of laser bars each extending in the longitudinal direction are stacked along the short direction. 10. apparatus. A light emitting device according to any one of claims 1 to 9,
The light passing through the light-shielding portion is projected toward an object and receives reflected light reflected by the object, and includes a plurality of light-receiving segments arranged along a direction corresponding to the longitudinal direction. And a light receiving element having a surface.   The light emitting and receiving device according to claim 10, further comprising a light receiving optical system that collects the reflected light so that the reflected light is made to enter the entire light receiving surface of the light receiving element in the longitudinal direction.   The light emitting and receiving device according to claim 10, further comprising a deflecting element configured to deflect the light having passed through the light blocking unit in a variable direction and project the light toward the object. A light emitting and receiving device according to any one of claims 10 to 12,
A distance measuring unit for measuring a distance to the object based on a result of receiving the reflected light by the light receiving element.

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