JP2024036526A - Light projecting device, projecting/receiving device, and distance measuring device - Google Patents

Abstract

A light projecting device capable of projecting light with reduced intensity unevenness is provided. The present invention includes a light source that emits light having a cross-sectional shape having a longitudinal direction and a transverse direction, and a light shielding part that blocks light from an end in the longitudinal direction. [Selection diagram] Figure 3

Description

The present invention relates to a light projecting device that projects light, a light projecting/receiving device that projects and receives light, and a distance measuring device that measures optical distance.

2. Description of the Related Art Distance measuring devices have been known that measure the distance to an object by irradiating light onto the object and detecting the light reflected by the object. Further, a scanning type distance measuring device is known that measures distances to a plurality of objects by performing optical scanning. For example, Patent Document 1 discloses an optical radar device including a light projecting section, a light receiving section, and distance measuring means.

Japanese Patent Application Publication No. 2007-85832

For example, a distance measuring device is provided with a light projecting section that projects a laser beam for distance measurement, and a light receiving section that receives light reflected by an object. Further, the structure of the light projecting section and the light receiving section is, for example, a structure in which the light projecting section projects a laser beam in a predetermined elongated beam shape, and the light receiving section receives reflected light from a target object using a plurality of light receiving elements. can be mentioned. In this case, light can be emitted and received at once to a plurality of target areas (a plurality of objects, a plurality of surface areas of the target objects, etc.).

Here, in consideration of accurate distance measurement for each of the plurality of target areas, it is preferable, for example, that light of uniform intensity is projected onto each of the plurality of target areas. That is, it is preferable that there be little intensity unevenness in the projected light beam.

The present invention has been made in view of the above points, and one of the objects of the present invention is to provide a light projecting device capable of projecting light with reduced intensity unevenness. Further, the present invention provides a light projecting/receiving device that can accurately project and receive light by projecting light with reduced intensity unevenness, and a distance measuring device that can perform accurate distance measurement. is one of the objectives.

The invention according to claim 1 is characterized in that it includes a light source that emits light having a cross-sectional shape having a longitudinal direction and a transverse direction, and a light shielding part that blocks the end portion of the light in the longitudinal direction.

1 is a diagram showing the overall configuration of a distance measuring device according to a first embodiment. FIG. 3 is a diagram showing a light emitting surface of a light source in the distance measuring device according to the first embodiment. 3 is a diagram showing an example of the configuration of a light shielding section in the distance measuring device according to the first embodiment. FIG. FIG. 3 is a diagram showing a light receiving surface of a light receiving element in the distance measuring device according to the first embodiment. FIG. 2 is a diagram showing an example of the configuration of a light receiving optical system in the distance measuring device according to the first embodiment.

Examples of the present invention will be described in detail below.

FIG. 1 is a schematic layout diagram of a distance measuring device 10 according to a first embodiment. The distance measuring device 10 is a scanning type distance measuring device that performs optical scanning of a predetermined area (hereinafter referred to as a scanning area) R0 and measures the distance to an object OB existing within the scanning area R0. The distance measuring device 10 will be explained using FIG. 1. Note that FIG. 1 schematically shows the scanning area R0 and the object OB.

First, the distance measuring device 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 a laser beam having a peak wavelength in the infrared region as the primary light L1, and emits it intermittently. Further, 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 (intermediate image) of the primary light L1, that is, an image showing the cross-sectional shape (beam shape) of the primary light L1. The imaging optical system 12 includes, for example, a relay lens.

The distance measuring device 10 includes a light shielding section 13 that blocks part of the primary light L1. In this embodiment, the light shielding part 13 is arranged at a position (imaging point) where an image of the primary light L1 is formed. The primary light L1 that has passed through the light shielding section 13 is outputted from the light shielding section 13 as secondary light L2.

In this embodiment, the light shielding section 13 is a light shielding plate having an opening. In this embodiment, a part of the primary light L1 is blocked by the light blocking section 13. Further, the primary light L1 that is not blocked by the light shielding part 13 passes through the opening of the light shielding part 13 as secondary light (hereinafter sometimes referred to as flooded light) L2. Further, in this embodiment, the light shielding section 13 is a reflecting plate that is reflective to the primary light L1.

The distance measuring device 10 includes a light receiving element (first light receiving element) 14 that receives reflected primary light L1R, which is part of the primary light L1 reflected by the light shielding part 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 includes a light projection optical system 15 that projects the secondary light L2, that is, the primary light L1 that has passed through the light shielding section 13. The projection optical system 15 includes, for example, at least one lens.

The distance measuring device 10 includes a deflection element (first deflection element) 16 that deflects the secondary light L2 in a variable direction and projects it as a tertiary light (hereinafter sometimes referred to as scanning light) L3. The deflection element 16 performs periodic operations to periodically change the deflection direction of the secondary light L2. The deflection element 16 bends the traveling direction of the secondary light L2 and outputs the secondary light L2, and periodically changes the bending direction. The secondary light L2 deflected by the deflection element 16 is projected toward the scanning region R0 as tertiary light L3.

In this embodiment, the deflection element 16 includes at least one rotating mirror 16A that rotates around a rotation axis AY and reflects the secondary light L2. For example, deflection element 16 includes a polygon mirror. In this embodiment, the deflection 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 this embodiment, the tertiary light L3 is the secondary light L2 reflected by the rotating mirror 16A of the deflection element 16.

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

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

Therefore, for example, the scanning region R0 includes the directional range in the height direction along the longitudinal direction (hereinafter referred to as the 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 directional range in the width direction along the direction D2 (hereinafter referred to as the second direction) corresponding to the variable range of the direction, and a range in the distance direction (i.e., a depth range) in which the tertiary light L3 can maintain a predetermined intensity. , can be defined as a cone-shaped space with .

Furthermore, when a virtual plane that is a predetermined distance away from the deflection element 16 in the scanning region R0 is defined as the scanning plane R1, the scanning plane R1 is a two-dimensional plane that extends along the first and second directions D1 and D2. can be defined as a specific area. The tertiary light L3 is projected toward the scanning region R0 so as to scan the scanning surface R1. Further, in this 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 an object OB (that is, an object or substance that reflects or scatters the secondary light L2) exists in the scanning region R0, the tertiary light L3 is transmitted to the object OB. reflected or scattered by A part of the tertiary light L3 reflected by the object OB passes through almost the same optical path as the tertiary light L3 as the fourth order light (hereinafter sometimes referred to as reflected light) L4. travels in the opposite direction and returns to the deflection element 16.

The distance measuring device 10 is arranged on the optical path of the fourth-order light L4, and in this embodiment, the light that is common to the second-order light L2 and the fourth-order light L4 between the deflection element 16 and the light projection optical system 15 (light shielding part 13). It has a deflection element (second deflection element) 17 that is provided on the road and deflects the fourth-order light L4. For example, the deflection element 17 is a light separation element that separates the secondary light L2 and the fourth-order light L4 by transmitting the second-order light L2 and reflecting the fourth-order light L4, and in this embodiment, it is a beam splitter. be.

In other words, in this embodiment, the deflection element 16 is a movable deflection element for scanning that deflects the secondary light L2 in a variable direction by operating. On the other hand, the deflection element 17 is a fixed deflection element.

The distance measuring device 10 includes a light receiving optical system 18 that receives the fourth-order light L4 deflected by the deflecting element 17. The light receiving optical system 18 collects and shapes the fourth-order light L4. 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 a focal position of the fourth-order light L4 collected by the light receiving optical system 18. For example, the light receiving element 19 includes at least one detection element that detects the fourth-order light L4 and generates an electric signal according to the fourth-order light.

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

The distance measuring device 10 includes a control section 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 this 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 a part of the primary light L1 and monitors the primary light L1. and, including. Further, the control unit 20 drives the light receiving element 14, the deflection element 16, and the light receiving element 19.

The control unit also includes a distance measuring unit 23 that measures the distance to the object OB based on the result of the fourth-order light L4 received by the light receiving element 19. In this embodiment, the distance measuring section 23 detects a pulse indicating the fourth-order light L4 from the electrical signal. Further, the distance measuring unit 23 uses a time-of-flight method based on the time difference between the emission timing of the tertiary light L3 and the reception timing of the fourth order light L4 to reach the object OB (or a part of its surface area). Measure the distance. Further, the distance measuring unit 23 generates data (distance measurement data) indicating the measured distance information.

Further, in this embodiment, the distance measuring unit 23 distinguishes the scanning area R0 (scanning surface R1) into a plurality of distance measuring points (scanning points), and obtains the distance measuring results (distances) of each of the plurality of distance measuring points. An image (distance measurement image) of the scanning area R0 is generated in which the value) is expressed as a pixel. In this embodiment, the distance measuring unit 23 associates the distance measuring point with information indicating the displacement of the rotating mirror 16A, and generates image data representing a two-dimensional map or a three-dimensional map of the scanning area R0.

Further, the distance measuring unit 23 uses, for example, a period of change in the projection direction of the tertiary light L3, that is, a scanning period that is a period of scanning the scanning area R0, as a generation period of the distance measuring image, and generates one image for each scanning period. Generate a ranging image.

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

FIG. 2 is a diagram schematically showing the light exit surface 11A of the light source 11. In this embodiment, the light source 11 has three laser bars E1, E2 and E3, each extending in a first direction D1, and these laser bars E1-E3 extend in a second direction D2 (i.e. laser bars E1-E3). It has a stacked structure along the lateral direction of each E3.

Each of the laser bars E1 to E3 emits a linear or elliptical laser beam having a cross-sectional shape (beam shape) whose longitudinal direction is the first direction D1 and whose transverse direction is the second direction D2. Furthermore, each of the laser bars E1 to E3 is lined up along the second direction D2 and emits laser light along optical axes that extend parallel to each other.

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

FIG. 3 is a diagram schematically showing the configuration of the light shielding section 13 and the cross-sectional shape of the secondary light L2 generated by the light shielding section 13. As shown in FIG. 3, in this 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 the longitudinal direction and the transverse direction, respectively. includes a plurality of primary laser beams L11, L12, and L13. For example, primary laser beams L11, L12, and L13 correspond to laser beams emitted from 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 transverse direction, and arranged along the transverse direction. emits light.

Further, in this embodiment, the light shielding part 13 is arranged at a position where the image (intermediate image) L1P of the light exit surface 11A of the primary light L1 in the light source 11 is formed by the imaging optical system 12. FIG. 3 schematically shows each of the images of the light exit surface of the primary laser beams L11 to L13 forming the image L1P.

Further, the primary laser beams L11, L12, and L13 that have passed through the light shielding section 13 pass through the light shielding section 13 as secondary laser beams L21, L22, and L23, respectively. The secondary light L2 includes these three secondary laser beams 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 transverse direction, respectively.

Further, as shown in FIG. 3, in this embodiment, the light shielding section 13 is configured and arranged to shield each end of the primary laser beams L11 to L13. Further, in this embodiment, the light shielding section 13 is arranged so that the lengths of the secondary laser beams L21 to L23, that is, the primary laser beams L11 to L13 that have passed through the light shielding section 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 position 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 explained. For example, when trying to increase the measurable distance of the distance measuring device 10, it is conceivable to increase the intensity of the light projected as the tertiary light L3. In consideration of emitting high-intensity primary light L1, it is conceivable to use a high-output light source as the light source 11.

Also, considering that the fourth order light L4 is obtained from multiple areas within the scanning area R0 at once, it is considered that a laser element in which the laser bars E1 to E3 as described above are stacked is used as the light source 11. It will be done. Thereby, for example, it is possible to obtain the high-output linear tertiary light L3 while suppressing the increase in size or complexity of the optical system.

On the other hand, in a stacked laser element as the light source 11, the shapes of the light emitting surfaces of the laser bars E1 to E3 are slightly different. Specifically, as shown in FIG. 2, for example, the lengths in the longitudinal direction (bar lengths) of the laser bars E1 to E3 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 beams L11 to L13 has different intensities as a whole between the center portion and the end portions in the first direction D1.

Therefore, for example, the light corresponding to the center of the first direction D1 of the primary light L1 has sufficient intensity, while the light corresponding to the end of the first direction D1 of the primary light L1 has sufficient intensity. It may not have the strength. Therefore, if this primary light L1 is directly projected as tertiary light L3, an area within the scanning area R0 that is irradiated with a sufficient amount of tertiary light L3 and a region that is irradiated with a sufficient amount of tertiary light L3 There may be areas where this is not possible. Therefore, there may be unevenness in distance measurement accuracy within the scanning region R0, or there may be a region where the measurable distance is shorter than in other regions.

In contrast, in this embodiment, a light shielding section 13 is arranged to shield the ends of each of the primary laser beams L11 to L13 in the first direction D1. Therefore, the lengths of the secondary laser beams L21 to L23 in the first direction D1 are made uniform, and the intensity of the secondary laser beam L2 as a whole along the first direction D1 is made uniform. Therefore, the amount of tertiary light L3 projected onto the scanning region R0 is made uniform, and scanning and distance measurement can be performed with stable accuracy over the entire scanning region R0.

Further, 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 lower intensity than the primary light L1. On the other hand, the light source control section 21 of the control section 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 the designed light amount. That is, the light source 11 emits the primary light L1 with an output based on the amount of secondary light L2 that is the primary light L1 that has passed through the light shielding part 13.

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

In this 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 whose light intensity is closer to the light intensity of the tertiary light L3 than the primary light L1. Therefore, it is possible to project the tertiary light L3 while satisfying the output limit of the laser beam and performing appropriate output adjustment.

Further, in this embodiment, the light shielding part 13 has a reflective property for the primary light L1. Further, a light receiving element 14 is provided that receives the reflected primary light L1R reflected by the light shielding part 13. Furthermore, the monitoring unit 22 monitors the primary light L1 based on the result of reception of the reflected primary light L1R by the light receiving element 14.

That is, when the light shielding part 13 reflects a part of the primary light L1, the reflected primary light L1 can be used for monitoring the light source 11. Therefore, the operation of the light source 11 can be monitored simply by providing the light receiving element 14. In other words, when the light shielding part 13 has reflectivity for the primary light L1, it receives the primary light L1 reflected by the light shielding part 13 and converts the primary light L1 (for example, the light amount of the primary light L1) into the primary light L1. By providing the monitoring unit 22 for monitoring, the distance measuring device 10 can be provided with 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. 4, the light receiving element 19 has a light receiving surface 19R made up of 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 a line and has a linear light receiving surface 19R.

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

FIG. 5 is a diagram showing a configuration example of the light receiving optical system 18 and the light receiving element 19. In this embodiment, the light-receiving optical system 18 condenses the fourth-order light L4 so 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, each of the light receiving segments 19A generates an electric signal corresponding to a portion of the fourth order light L4 received 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 part 13 (in this embodiment, the length of the beam in the first direction D1). The light condensing characteristics are adjusted to allow operation. Therefore, accurate light receiving operation can be performed in all of the light receiving segments 19A.

As described above, in this embodiment, the distance measuring device 10 transmits the first direction of the primary light L1 to the light source 11 that emits the primary light L1 having a cross-sectional shape having the first direction D1 as the longitudinal direction. It has a light shielding part 13 that shields the end of D1 from light. Therefore, the light at the end of the primary light L1, that is, the light whose intensity is low in the primary light L1, is blocked. Therefore, it is possible to project the secondary light L2 with reduced intensity unevenness, and accurate scanning and distance measurement can be performed.

In this 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 lights (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 transverse direction (for example, a second direction D2). It suffices if it is configured to do so. For example, the light source 11 may include various light emitting elements and may have an optical system that shapes the light emitted from the light emitting elements as described above.

Furthermore, the light source 11 is not limited to being configured to emit a plurality of primary laser beams L11 to L13. For example, the light source 11 may be configured to emit only one primary laser beam (for example, only the primary laser beam L12) as the primary light L1.

Specifically, when emitting the primary light L1 having a linear cross-sectional shape like the primary light L1, the end portions of the primary light L1 may have lower intensity than the central portion. Further, the intensity of the primary light L1 at the end portions may not be stable compared to the intensity at the center portion. In this way, the characteristics of the end portion of the primary light L1 may be more unstable than the characteristics of the central portion of the primary light L1. Therefore, it is preferable to project only the central portion of the primary light L1. Therefore, by blocking the end of the primary light L1 emitted from the light source 11 in the first direction D1, it is possible to project the secondary light L2 with stable intensity.

Further, in this embodiment, a case has been described in which the light shielding section 13 is configured to shield each of the ends of the primary laser beams L11 to L13. However, the configuration of the light shielding section 13 is not limited to this. The light blocking section 13 may be configured to block at least one end of the primary laser beams L11 to L13.

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

Moreover, the light shielding part 13 is not limited to a case where the length of the light passing through the light shielding part 13 in the first direction D1 is made equal. The light shielding part 13 includes at least one light that is more prominent than other lights in the first direction D1 (for example, only the primary laser beam L13, or the primary laser beam L12 and It is only necessary that the end portion of the first direction D1 (L13 only) is configured to block light. Even in this case, it can be expected that the intensity unevenness of the primary light L1 will be reduced.

Furthermore, in the present embodiment, a case has been described in which the light shielding portion 13 has reflectivity with respect to the primary light L1. However, the light blocking section 13 may be configured to block (not project) the end of the primary light L1 in the first direction D1. For example, the light shielding part 13 may have absorbency for the primary light L1.

In addition, when the light shielding part 13 does not have reflectivity with respect to the primary light L1, the light receiving element 14 does not need to be provided. In this case, the light source 11 may be monitored by other general means without using the light shielding part 13.

Furthermore, in the present embodiment, a case has been described in which the light shielding section 13 is composed of a light shielding plate having an opening on the optical path of a part of the primary light L1 (in the present embodiment, the central part). However, the configuration of the light shielding section 13 is not limited to this. For example, the light shielding part 13 may be a light transmitting plate that has a transmitting part that transmits the primary light L1 on the central optical path of the primary light L1, and other parts have light shielding properties. Moreover, the light shielding part 13 may have a plurality of light shielding plates.

Further, the light blocking section 13 may be configured to block only one end 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 is the most protruding at one end in the first direction D1, and the primary laser beam L13 is the most protruding at the other end. L12 may be the most prominent. In this case, the light blocking section 13 is configured to block the end of the primary laser beam L13 at one end, and block the end of the primary laser beam L12 at the other end. It's okay.

Further, in this embodiment, an imaging optical system 12 that forms an image L1P of the primary light L1 is provided, and the light shielding part 13 is arranged at a position where the image L1P of the primary light L1 is formed. I explained the case where However, the position of the light shielding part 13 is not limited to this.

For example, the distance measuring device 10 may not include the imaging optical system 12. Moreover, the light shielding part 13 may be arranged very close to the light emitting surface 11A of the light source 11. That is, the primary light L1 may be configured such that a portion of the primary light L1 is blocked by the light blocking section 13 immediately after being emitted from the light source 11.

Note that in order to reliably block the end portion of the primary light L1, after placing the imaging optical system 12, the light blocking section 13 is placed at the imaging position of the image L1P of the light output surface 11A of the light source 11. It is preferable to do so. Specifically, when the light shielding section 13 is arranged at a position other than the imaging position of the image L1P, the end portion of the primary light L1 that has passed through the light shielding section 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 part 13, and includes an imaging optical system 12 that forms an image L1P of the light output surface 11A of the light source 11. It is preferable to have. Moreover, it is preferable that the light shielding part 13 be arranged at a position where this image L1P is formed.

Further, in this embodiment, a 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 with an intensity corresponding to the amount of the secondary light L2. However, the light source 11 may be configured to emit the primary light L1 in a predetermined manner, or to be able to adjust the emission manner of the primary light L1, for example.

As described above, in this 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 transverse direction (second direction D2). a light source 11 that blocks the longitudinal end of the light, a light shielding part 13 that shields the end of the light in the longitudinal direction, and a light shielding part 13 that deflects the light (secondary light L2) that has passed through the light shielding part 13 in a variable direction and directs it toward the object OB in the scanning area R0. It has a deflection element 16 that projects light toward the target.

Further, the distance measuring device 10 receives reflected light (fourth-order light L4) that is the light (third-order light L3) reflected by the object OB, and a plurality of light beams arranged along a direction corresponding to the longitudinal direction. The light-receiving element 19 has a light-receiving surface 19S composed of light-receiving segments 19A, and a distance measuring section 23 that measures the distance to the object OB based on the result of reception of the reflected light by the light-receiving element 19. Therefore, it is possible to provide the distance measuring device 10 that can perform accurate distance measurement by projecting light with reduced intensity unevenness.

Note that the result of the fourth-order light L4 received by the light-receiving element 19 can also 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 have the distance measuring section 23. In this case, for example, the light source 11, light shielding unit 13, deflection element 16, and light receiving element 19 in the distance measuring device 10 function as a scanning device, that is, a scanning type light projecting and receiving device.

Further, the distance measuring device 10 may not include the deflection element 16 in addition to the distance measuring section 23. In this case, for example, the light source 11, the light shielding section 13, and the light receiving element 19 in the distance measuring device 10 function as a non-scanning type light projecting and receiving device. Even in this case, it is possible to emit and receive light using, for example, light of uniform intensity. That is, the present invention can be implemented as a light projecting and receiving device that can accurately project and receive light by projecting light with reduced intensity unevenness.

Furthermore, the distance measuring device 10 does not need to have the light receiving element 19. In this case, the light source 11 and the light shielding section 13 function as a light projecting device. In this case, for example, light with uniform intensity can be projected. That is, the present invention can be implemented as a light projecting device capable of projecting light with reduced intensity unevenness.

As described above, for example, the light projection device in this embodiment emits light (primary light L1) having a cross-sectional shape having a longitudinal direction (first direction D1) and a transverse direction (second direction D2). The light source 11 has a light source 11 that provides light, and a light shielding section 13 that blocks the end of the light in the longitudinal direction. Therefore, it is possible to project light with reduced intensity unevenness.

10 Distance measuring device 11 Light source 13 Light shielding part

Claims (1)

a light source that emits light having a cross-sectional shape having a longitudinal direction and a transverse direction in a cross section perpendicular to the traveling direction;
A light projection device comprising: a light shielding portion that shields the end portion of the light in the longitudinal direction.

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