JP2022159438A - Ranging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ranging device that observes safety standards regarding output of laser beams and can precisely measure distance to an object positioned in the distance.

SOLUTION: A ranging device: a plurality of light projection parts for projecting emission light; and a light reception part for receiving reflection light obtained by reflection of emission light by an object. A light projection part other than a first light projection part from among the plurality of light projection parts is a second light projection part arranged so as to be capable of projecting emission light in a light axis differing from a light axis of the light reception part, and an instantaneous light projection field of emission light emitted by the second light projection part is larger than an instantaneous light projection field of emission light emitted by the first light projection part in each position separated by predetermined distance in a light axis direction of the light reception part from the light reception part.

SELECTED DRAWING: Figure 4B

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a distance measuring device that measures the distance to an object.

An optical rangefinder, for example, scans a target area with a laser beam to measure the distance to the target, that is, measures the distance.

As such a rangefinder, for example, Japanese Patent Laid-Open No. 2002-200001 discloses an optical rangefinder in which a drive section for driving the light reflection surface of an optical scanning device to oscillate includes at least one of a phase difference changer and an amplitude changer. It is

JP 2011-053137 A

Laser light scatters when it hits an object. For this reason, the intensity of the laser beam received by the distance measuring device becomes weaker as the object becomes farther from the distance measuring device. Therefore, in order to measure the distance of an object located far from the distance measuring device, it is desirable to emit laser light with a high output.

However, since laser light has a high power density and may be harmful to the human body, the output of laser light is restricted by safety standards. If this safety standard is observed, one of the problems is that the amount of returned light becomes small when measuring a long distance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a distance measuring apparatus that complies with safety standards regarding the intensity of laser light and that can accurately measure the distance of a distant object. This is one of the issues.

A distance measuring device according to claim 1 of the present application comprises a plurality of light projecting units for projecting emitted light, and a light receiving unit for receiving reflected light of the emitted light reflected by an object, wherein the plurality of A light projecting part other than the first light projecting part among the light projecting parts is a second light projecting part arranged so as to project the emitted light on an optical axis different from the optical axis of the light receiving part, The momentary light field of the output light emitted from the second light projecting unit is obtained at each position separated from the light receiving unit by a predetermined distance in the optical axis direction of the light receiving unit. It is characterized by being larger than the instantaneous projection field of emitted light.

1 is a block diagram showing the configuration of a distance measuring device according to Example 1; FIG. FIG. 4 is an explanatory diagram illustrating the principle of operation of the projection system of the rangefinder according to the first embodiment; FIG. 4 is an explanatory diagram for explaining the principle of operation of the light receiving system of the distance measuring device according to the first embodiment; FIG. 2 is a conceptual diagram for explaining the instantaneous light field of the light projecting part and the instantaneous field of view of the light receiving part of FIG. 1; 4 is a conceptual diagram illustrating an instantaneous light field of the light projecting part and an instantaneous field of view of the light receiving part according to the distance from the distance measuring device according to the first embodiment; FIG. FIG. 10 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit according to the distance from the distance measuring device according to the second embodiment; FIG. 12 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit according to the distance from the distance measuring device according to the third embodiment; FIG. 12 is a conceptual diagram illustrating the instantaneous light field of the light projecting unit and the instantaneous field of view of the light receiving unit according to the distance from the distance measuring device according to the fourth embodiment; FIG. 11 is a block diagram showing the configuration of a distance measuring device according to Example 5; FIG. 12 is a perspective view showing an arrangement example of a light projecting unit and a light receiving unit of a distance measuring device according to Example 5; FIG. 10 is a conceptual diagram showing a mode in which emitted light is emitted from the light projecting section of FIG. 9; FIG. 11 is a conceptual diagram illustrating outgoing light emitted from a rangefinder according to a modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment; FIG. 14 is a conceptual diagram illustrating an instantaneous light field of the light projecting unit and an instantaneous field of view of the light receiving unit at a predetermined distance from the distance measuring device according to the modification of the fifth embodiment;

FIG. 1 shows functional blocks of a distance measuring device 100 according to this embodiment. In FIG. 1, light projection units 10a and 10b are light emitting devices that emit emitted light. The light projection units 10a and 10b have the same configuration. The light sources 11 of the light projection units 10a and 10b are, for example, laser elements capable of emitting pulsed light as emitted light.

The light deflection element 12 has an emitted light reflecting member including a light reflecting surface (not shown). The light deflection element 12 can reflect the pulsed light on the light reflecting surface and emit the scanning light toward a predetermined area to be scanned (hereinafter referred to as a scanning target area). Therefore, the light deflection element 12 functions as an output light deflection element.
The optical deflection element 12 can variably deflect the direction of emitted light. The scanning light reflected by the object existing in the scanning target area returns toward the distance measuring device 100 as reflected light. A MEMS mirror device, a polygon mirror, or the like can be used as the light deflection element 12 . Also, the optical deflection element 12 may be an optical deflection element that does not have a light reflecting surface. An acousto-optic deflector (AO deflector) or the like can be given as such an optical deflector.

The light projecting/receiving unit 20 is a light emitting device that emits emitted light, and is also a light receiving device that receives reflected light and generates a light reception signal, which is an electrical signal. Therefore, the light projecting/receiving section 20 functions as a light projecting section as well as a light receiving section.

The light source 21 of the light projecting/receiving unit 20 is, for example, a laser element capable of emitting pulsed light as emitted light. The light projecting/receiving unit 20 has a light receiving element 22 capable of receiving reflected light and generating a light receiving signal, which is an electrical signal. As the light receiving element 22, for example, an avalanche photodiode (APD) or the like can be adopted.

The light deflection element 23 can reflect the pulsed light emitted from the light source 21 on the light reflecting surface and emit the scanning light toward the scanning target area. Further, the light deflection element 23 can reflect toward the light receiving element 22 the reflected light, which is the pulsed light reflected by the object in the scanning target area on the light reflecting surface. Therefore, the light deflection element 23 functions as an emitted light deflection element and a reflected light deflection element. In other words, the optical deflection element 23 can variably deflect the direction of the emitted light and variably deflect the direction of the reflected light from the object to guide it to the light receiving element 22 . The light deflecting element 23 has an emitted light reflecting member including a light reflecting surface (not shown), and this emitted light deflecting member also functions as a reflected light polarizing member.

The control unit 30 controls pulsed light emitted from the light source 21 of the light projecting/receiving unit 20 and the light sources 11 of the light projecting units 10a and 10b, and controls the light deflection element 23 of the light projecting/receiving unit 20 and the light projecting units 10a and 10b. The angle of the light reflection surface of the light deflection element 12 is controlled.

The light source control unit 31 performs light emission control of the light source 21 of the light projecting/receiving unit 20 and the light sources 11 of the light projecting units 10a and 10b. Specifically, for example, the light emission is controlled by referring to a table (not shown) that defines the light emission timing so that the light source 21 and the light source 11 emit pulsed light.

The mirror control section 32 controls the angle of inclination of the light reflection surface of the light deflecting element 23 of the light projecting/receiving section 20 and the light deflecting elements 12 of the light projecting sections 10a and 10b. Specifically, the mirror control unit 32 controls the light deflection element 12 so that the scanning target area is scanned by pulsed light emitted by the light source 11 and the light source 21 and reflected by a light reflecting surface (not shown). and controls the optical deflection element 23 . The mirror control unit 32 also controls the direction of the light reflecting surface of the emitted light reflecting member of the light deflecting element 23 of the light projecting/receiving unit 20 and the light of the emitted light reflecting member of the light deflecting element 12 of the light projecting unit 10a and the light projecting unit 10b. The optical deflection element 23 and the optical deflection element 12 are controlled so that the direction with respect to the reflecting surface is interlocked.

A distance measurement unit 40 as a distance measurement unit calculates the distance between the distance measurement device 100 and an object in the scanning target area. The calculation of the distance between the distance measuring device 100 and the object in the scanning target area is performed based on the received light signal generated by the light receiving element 22, and for example, the time-of-flight method is used.

Specifically, the distance measurement unit 40 detects the emission time of one pulsed light emitted by the light source 11 and the light source 21, and the light receiving element 22 to acquire the light reception time detected. Then, the distance between the distance measuring device 100 and the object is calculated based on the time difference between the emission time and the light reception time.

FIG. 2 is a conceptual diagram showing the operation of the light projecting system of the light projecting/receiving unit 20 and the light projecting units 10a and 10b. In FIG. 2, a beam splitter BS is provided between the light source 21 and the optical deflection element 23 . The beam splitter BS is an optical element that passes the light beam incident from the light source 21 side to the light deflection element 23 side. Therefore, the light beam emitted from the light source 21 is incident on the optical deflection element 23 via the beam splitter BS. The optical deflection element 23 reflects the incident emitted light EL toward the scanning target region R. As shown in FIG. The beam splitter BS is not arranged in the light projection units 10a and 10b.

Specifically, the optical deflection element 23 reflects the light beam toward the scanning target region R in a manner of scanning by swinging the movable portion. As a result, the irradiation direction of the emitted light EL reflected by the optical deflection element 23 changes. Specifically, the emitted light EL is reflected by the light deflection element 23 so that a desired trajectory is drawn on a virtual plane VS, which is a virtual plane in the reflection direction of the emitted light EL. The distance measuring device 100 performs distance measurement of an object OB existing in a scanning target area R. FIG. Note that the virtual surface VS does not actually exist. The trajectory drawn on the virtual surface VS is preferably a raster scanning trajectory, a Lissajous scanning trajectory, or the like, but is not limited thereto.

FIG. 3 is a conceptual diagram showing the operation of the light receiving system of the light projecting/receiving unit 20. As shown in FIG. In FIG. 3, when an object OB exists in the scanning target area R, the reflected light RL reflected from the object OB is incident on the light deflection element 23 and is incident on the light receiving element 22 via the beam splitter BS. The light receiving element 22 converts the incident reflected light RL into an electric signal and supplies the electric signal to the distance measuring section 40 . The distance measuring unit 40 measures the distance to the object OB based on the time when the light beam is emitted and the time when the light beam is received.

4A shows the instantaneous field of view (iFOI) of the light projecting/receiving unit 20 and light projecting units 10a and 10b and the instant field of view (iFOV) of the light projecting/receiving unit 20 along the optical axis AX. It shows the area viewed from the vertical direction. The optical axis AX is the optical axis of the emitted light EL emitted from the light projecting/receiving section 20 when the reflecting surface MR of the light deflection element 12 is not inclined. The state in which the reflecting surface MR does not tilt is, for example, a stationary state in which the light reflecting surface MR of the MEMS mirror device does not oscillate.

FIG. 4B shows light in the instantaneous field of view (iFOI) of the light projecting/receiving unit 20 and the light projecting units 10a and 10b and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 according to the distance from the distance measuring device 100 according to the present embodiment. It shows a cross section in a direction perpendicular to the axis AX.

Here, the instantaneous projection field (iFOI) is a region that is momentarily irradiated with the emitted light EL. Further, the instantaneous field of view (iFOV) is an angle seen by the light receiving surface of the light projecting and receiving unit 20, and is an area that the light receiving element 22 can see instantaneously.

The dashed-dotted lines in the figure indicate the instantaneous light field (iFOI(b)) of the light projecting section 10a and the instantaneous light field (iFOI(c)) of the light projecting section 10b. The instantaneous field of view (iFOI(a)) and the instantaneous field of view (iFOV) of part 20 are shown.

The light projecting units 10 a and 10 b are arranged apart from the light projecting/receiving unit 20 in the direction perpendicular to the optical axis AX of the light projecting/receiving unit 20 . Specifically, the light projecting units 10 a and 10 b have different emission points from the light projecting/receiving unit 20 . That is, the light projecting units 10 a and 10 b have different optical axes from the light projecting/receiving unit 20 .

A distance L1 is the distance from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and is a distance defined by safety standards. Distance L1 is, for example, 100 mm from rangefinder 100 . Safety standards are established based on the intensity of light at a given distance.

Each of the light projecting/receiving unit 20 and the light projecting units 10a and 10b emits pulsed light with an output that satisfies safety standards. That is, the intensity of the light projecting/receiving unit 20 and the light projecting units 10a and 10b at the distance L1 satisfies the safety standard. Further, the instantaneous light field (iFOI(b), iFOI(c)) of the emitted light EL emitted from the light projecting unit 10a and the light emitting unit 10b is the instantaneous light field (iFOI (a)). The instantaneous field of view (iFOI(a)) of the emitted light EL emitted by the light projecting/receiving unit 20 has the same size as the instantaneous field of view (iFOV). That is, the instantaneous light field (iFOI(b), iFOI(c)) of the emitted light EL emitted from the light projecting units 10a and 10b is larger than the instantaneous field of view (iFOV).

As shown in FIG. 4B, the overlapping manner of the instantaneous field of view (iFOV) and the instantaneous projected field of view (iFOIs (a) to (c)) changes according to the distance from the distance measuring device 100 to the section of interest. Here, among the emitted light beams EL emitted from the light projecting/receiving unit 20 and the light emitting units 10a and 10b, the intensity of the emitted light beam EL emitted within the instantaneous field of view (iFOV) at the distance from the distance measuring device 100 is Let the sum be the irradiation light intensity at the distance from the rangefinder 100 .

At the position of the distance L1, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20, the instantaneous light field (iFOI(b)) of the light projecting unit 10a, and the instantaneous field of view of the light projecting unit 10b in the instantaneous field of view (iFOV). The projection fields (iFOI(c)) are non-overlapping.

At the position of the distance L1, the light projecting/receiving section 20 can receive sufficient reflected light RL for distance measurement of the object OB. Therefore, the ranging device 100 can perform highly accurate ranging. The safety standard is judged at the position of the distance L1. Therefore, the distance measuring device 100 according to this embodiment satisfies the safety standards.

The distance L2 is the distance from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and is longer than the distance L1. Distance L2 is, for example, 50 m from rangefinder 100 .

At the position of the distance L2, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20, the instantaneous light field (iFOI(b)) of the light projecting unit 10a, and the instantaneous field of view of the light projecting unit 10b in the instantaneous field of view (iFOV). The projection fields (iFOI(c)) are non-overlapping. At the position of the distance L2, the light projecting/receiving unit 20 can obtain sufficient reflected light for distance measurement of the object OB. Therefore, the ranging device 100 can perform highly accurate ranging.

A distance L3 is the distance from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and is longer than the distance L2. Distance L3 is, for example, 100 m from rangefinder 100 .

At the position of the distance L3, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 in the instantaneous field of view (iFOV) overlaps with a part of the instantaneous light field (iFOI(b)) of the light projecting unit 10a. there is

Therefore, the instantaneous light fields (iFOI(a), iFOI(b )) overlap each other at a predetermined position along the optical axis AX of the light emitting/receiving section 20 on the instantaneous field of view (iFOV), that is, at a position of a distance L3.

At a distance L3, the instantaneous field of view (iFOI(a)) overlaps a portion of the instantaneous field of view (iFOI(b)) within the instantaneous field of view (iFOV). As a result, the intensity of the irradiation light applied to the object OB existing within the instantaneous field of view (iFOV) is increased. Therefore, at the position of the distance L3, the light projecting/receiving unit 20 can obtain sufficient reflected light RL for distance measurement of the object OB. Therefore, the ranging device 100 can perform highly accurate ranging.

A distance L4 is the distance from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and is longer than the distance L3. Distance L4 is, for example, 200 m from rangefinder 100 .

At the position of distance L4, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 in the instantaneous field of view (iFOV) is the instantaneous field of light (iFOI(b)) of the light projecting unit 10a and that of the light projecting unit 10b. It overlaps with part of the instantaneous field of view (iFOI(c)).

At the position of distance L4, the instantaneous field of view (iFOI(a)) overlaps the instantaneous field of view (iFOI(b)) and the instantaneous field of view (iFOI(c)), so it exists within the range of the instantaneous field of view (iFOV). The intensity of the irradiation light with which the object OB is irradiated is increased. Therefore, at the position of the distance L4, the light projecting/receiving unit 20 can obtain sufficient reflected light RL for measuring the distance of the object OB. Therefore, the ranging device 100 can perform highly accurate ranging.

As described above, the light projecting units 10 a and 10 b are arranged apart from the light projecting/receiving unit 20 . Further, the intensity of each emitted light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a and 10b satisfies the safety standard at the position of the distance L1.

Further, at a position at a distance L3 far away from the distance measuring device 100, since the instantaneous light fields (iFOI(a), iFOI(b)) of the light projecting/receiving unit 20 and the light projecting unit 10a overlap, the instantaneous field of view (iFOV) It is possible to increase the irradiation light intensity with which the object OB existing within the range is irradiated. Similarly, at the position of the distance L4, the instantaneous field of view (iFOI(a), iFOI(b) and iFOI(c)) of the light projecting/receiving unit 20 and the light projecting units 10a and 10b overlap each other, so the instantaneous field of view (iFOV ) It becomes possible to increase the irradiation light intensity with which the object OB existing within the range is irradiated. Therefore, according to the distance measuring device 100 according to the present embodiment, it is possible to observe the safety standards regarding the output of the laser beam and perform distance measurement of the object OB located far away.

In this embodiment, the instantaneous field of view (iFOI(b), iFOI(c)) of the light projecting unit 10a and the light projecting unit 10b is assumed to be larger than the instantaneous field of view (iFOV) of the light projecting/receiving unit 20. did. The instantaneous field of view (iFOI(b), iFOI(c)) of the light projecting unit 10a and the light projecting unit 10b may be equal to the instantaneous field of view (iFOV) of the light projecting/receiving unit 20. Accuracy of the deflection angles of the light polarization elements 12 and 23 is required. Therefore, by making the instantaneous light field (iFOI(b), iFOI(c)) of the light projecting unit 10a and the light projecting unit 10b larger than the instantaneous field of view (iFOV) of the light projecting/receiving unit 20, the light polarization elements 12 and 23 The precision of the deflection angle can be loosened. Since the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 shares the instantaneous field of view (iFOV) and the light polarizing element 23, there is no problem with the accuracy of the deflection angle. The field of view (iFOI(a)) and the instantaneous field of view (iFOV) may be the same.

Further, in this embodiment, the light projecting/receiving section 20 is configured to function as a light projecting section and a light receiving section. However, the light emitting/receiving section 20 may be provided with separate functions as a light emitting section and a light receiving section. That is, the light source 21 and the light deflection element 23 are provided as the light projecting section in the configuration of the light projecting/receiving section 20, and the light receiving element 22 and the light deflection element 23 are provided as the light receiving section in the configuration of the light projecting/receiving section 20. good too.

Furthermore, the light projecting/receiving unit 20 and the light projecting units 10a and 10b may emit the emitted light EL at different emission timings depending on the emission direction of the emitted light EL. Specifically, the emitted light EL may be emitted in order from the light projecting part that is farthest from a predetermined position in the emitting direction of the emitted light EL. By emitting the emitted light EL in this way, it is possible to align the timing at which the light projecting/receiving unit 20 receives the reflected light RL. Therefore, highly accurate distance measurement can be performed.

A range finder 100 according to a second embodiment will be described. The range finder 100 according to the second embodiment differs from the range finder 100 according to the first embodiment in the number of light projecting units arranged and the manner in which the instantaneous light fields overlap each other. It should be noted that the same reference numerals are assigned to the same portions of the same configuration as in the first embodiment, and the description thereof will be omitted, and the same will be applied hereinafter.

FIG. 5 shows the instantaneous field of view (iFOI) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 according to the distance from the distance measuring device 100 according to the present embodiment. It shows a cross section in a direction perpendicular to the axis AX.

The light projecting units 10 a to 10 d are spaced apart from the light projecting/receiving unit 20 in a direction perpendicular to the optical axis AX of the light projecting/receiving unit 20 . Specifically, the respective light projecting sections 10a to 10d are arranged at regular intervals. That is, the distance La from the light projecting/receiving unit 20 to the light projecting unit 10a is equal to the distance Lb from the light projecting unit 10a to the light projecting unit 10b. Further, the distance La from the light projecting/receiving unit 20 to the light projecting unit 10a is equal to the distance Lc from the light projecting/receiving unit 20 to the light projecting unit 10c. Further, the distance Ld from the light projecting unit 10c to the light projecting unit 10d is equal to the distance Lc from the light projecting/receiving unit 20 to the light projecting unit 10c.

Here, the instantaneous light field of the light projecting/receiving unit 20 is defined as an instantaneous light field (iFOI(a)). The instantaneous light field of the light projecting unit 10a is the instantaneous light field (iFOI(b)), the instantaneous light field of the light projecting unit 10b is the instantaneous light field (iFOI(c)), and the instantaneous light field of the light projecting unit 10c is the instantaneous light field. The projected light field (iFOI(d)) and the instantaneous projected light field of the light projecting unit 10d are defined as the instantaneous projected light field iFOI(e)).

The instantaneous projection fields (iFOI(a), iFOI(b), iFOI(c), iFOI(d), iFOI(e)) of the emitted light EL of the light projecting/receiving unit 20 and the light projecting units 10a to 10d are Equivalent to an instantaneous field of view (iFOV) of 20. Distances L2 to L4 are distances from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and are the same distances as in the first embodiment. In addition, the sum of the intensities of the emitted light beams EL emitted from the light projecting/receiving unit 20 and the light emitting units 10a to 10d, which is emitted within the instantaneous field of view (iFOV) at the distance from the distance measuring device 100 be the irradiation light intensity at the distance from the distance measuring device 100 . Also in this embodiment, the light projecting/receiving unit 20 and the light projecting units 10a to 10d emit the emitted light EL that satisfies the safety standards, so the description of the position at the distance L1 is omitted.

At the position of the distance L2, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 and the instantaneous light field of the light projecting units 10a to 10d (iFOI(b) to iFOI(e)) in the instantaneous field of view (iFOV) do not overlap.

At the position of the distance L2, the light projecting/receiving unit 20 can receive the reflected light RL sufficient for distance measurement of the object OB, so that distance measurement can be performed with high precision.

At the position of distance L3, the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 in the instantaneous field of view (iFOV) is the instantaneous field of light (iFOI(b)) of the light projecting unit 10a and that of the light projecting unit 10c. It overlaps with part of the instantaneous field of view (iFOI(c)).

At a distance L3, the instantaneous field of view (iFOI(a)), the instantaneous field of view (iFOI(b)) and the instantaneous field of view (iFOI(d)) overlap in the instantaneous field of view (iFOV). For this reason, the intensity of the irradiation light with which the object OB existing within the instantaneous field of view (iFOV) is irradiated is slightly less than doubled. Therefore, at the position of the distance L3, sufficient reflected light RL is obtained for distance measurement of the object OB.

At the position of the distance L4, the entire instantaneous field of view (iFOI(a) to iFOI(e)) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d overlaps in the instantaneous field of view (iFOV). In other words, the instantaneous field of view (iFOV) encompasses all of the instantaneous fields of view (iFOI(a)-iFOI(e)) of the emitter/receiver 20 and the emitters 10a-10d. That is, each of the optical axes E1 to E5 of the light projecting sections 10a to 10d and the optical axis AX of the light projecting and receiving section 20 overlap each other in the same region RC. It should be noted that the optical axes E1 to E5 overlapping each other in the region RC means not only that the optical axes E1 to E5 intersect each other in the region RC but also that the optical axes E1 to E5 are close to each other due to a twisted relationship. also means By overlapping each of the optical axes E1 to E5 and the optical axis AX in the region RC in this manner, the emitted light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a to 10d can be efficiently used for distance measurement. It becomes possible.

Specifically, at the position of the distance L4, since all the instantaneous projection fields (iFOI(a) to iFOI(e)) overlap, the irradiation applied to the object OB existing within the instantaneous field of view (iFOV) range is The light intensity is quintupled. Therefore, at the distance L4, sufficient reflected light RL can be obtained for distance measurement of the object OB.

As described above, the light projecting units 10a to 10d are arranged apart from the light projecting/receiving unit 20. FIG. In addition, the intensity of the emitted light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a to 10d satisfies the safety standard at the distance L1.

At a position at a distance L3 far away from the rangefinder 100, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20, the light projecting unit 10a, and the instantaneous light projecting unit 10c (iFOI ( Since a), iFOI(b) and iFOI(d)) overlap, it is possible to increase the irradiation light intensity with which the object OB existing within the instantaneous field of view (iFOV) is irradiated. Similarly, at the position of the distance L4, the instantaneous light fields (iFOI(a) to iFOI(e)) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d overlap in the instantaneous field of view (iFOV). It is possible to increase the irradiation light intensity with which the object OB existing within the instantaneous field of view (iFOV) is irradiated. Therefore, according to the distance measuring device 100 according to the present embodiment, it is possible to observe the safety standards regarding the output of the laser beam and perform distance measurement of the object OB located far away.

A range finder 100 according to a third embodiment will be described. The range finder 100 according to the third embodiment differs from the range finder 100 according to the second embodiment in that the instantaneous light fields of the plurality of light projecting units are overlapped.

FIG. 6 shows the instantaneous field of view (iFOI) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 according to the distance from the distance measuring device 100 according to the present embodiment. It shows a cross section in a direction perpendicular to the axis AX.

The light projecting units 10 a to 10 d are spaced apart from the light projecting/receiving unit 20 in a direction perpendicular to the optical axis AX of the light projecting/receiving unit 20 . Specifically, the light projecting units 10a to 10d are arranged at distances La to Ld, respectively, as shown in FIG. The distance La from the light projecting/receiving unit 20 to the light projecting unit 10a is equal to the distance Lc from the light projecting/receiving unit 20 to the light projecting unit 10c. The distance Lb from the light projecting unit 10a to the light projecting unit 10b is equal to the distance Ld from the light projecting unit 10c to the light projecting unit 10d. For example, the distances Lb and Ld are twice the distances La and Lc.

The instantaneous light field (iFOI(b), iFOI(c), iFOI(d), iFOI(e)) of the emitted light EL of the light projecting units 10a to 10d is the instantaneous light field of the light projecting/receiving unit 20 (iFOI(a) ) and four times the instantaneous field of view (iFOV) of the emitter/receiver 20 .

Distances L2 to L4 are the distances from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and are the same as in the first embodiment. In the present embodiment as well, the light projecting/receiving unit 20 and the light projecting units 10a to 10d emit emitted light EL that satisfies the safety standards, so the description of the position of the distance L1 is omitted.

At the position of the distance L2, the instantaneous light field (iFOI(a)) and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 are the instantaneous light fields (iFOI(b) to iFOI(e)) of the light projecting units 10a to 10d. do not overlap.

At the position of the distance L2, the light projecting/receiving unit 20 can receive the reflected light RL sufficient for distance measurement of the object OB, so that distance measurement can be performed with high accuracy.

At the position of the distance L3, the instantaneous field of view (iFOI(a)) and the instantaneous field of view (iFOV) of the light projecting/receiving section 20 are the same as the instantaneous field of view (iFOI(b)) of the light projecting section 10a and the instantaneous field of view (iFOI(b)) of the light projecting section 10c. Part of the light field (iFOI(d)) overlaps.

At the position of the distance L3, the instantaneous field of view (iFOI(a)), the instantaneous field of view (iFOI(b)), and the instantaneous field of view (iFOI(d)) overlap in the instantaneous field of view (iFOV). The intensity of the irradiation light applied to the object OB existing within the field of view (iFOV) is increased by 1.5 times. Therefore, at the position of the distance L3, sufficient reflected light RL is obtained for distance measurement of the object OB.

At the position of the distance L4, the instantaneous field of view (iFOV) of the light projecting sections 10a to 10d (iFOI(b) to iFOI(e)) completely overlap each other in the instantaneous field of view (iFOV). Further, the instantaneous light field (iFOI(a)) of the light projecting/receiving unit 20 and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 are the instantaneous light field (iFOI(b) to iFOI(e)) of the light projecting units 10a to 10d. are overlapped so that the whole is included in .

At the position of the distance L4, all the instantaneous projection fields (iFOI (a) to iFOI (e)) overlap in the instantaneous field of view (iFOV), so that the object OB existing within the instantaneous field of view (iFOV) The intensity of the irradiated light is doubled. Therefore, at the distance L4, sufficient reflected light RL can be obtained for distance measurement of the object OB.

As described above, the light projecting units 10a to 10d are arranged apart from the light projecting/receiving unit 20. FIG. In addition, the intensity of the emitted light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a to 10d satisfies the safety standard at the distance L1. That is, at the distance L1, the instantaneous field of view (iFOV) overlaps only the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 . Therefore, the illuminating light intensity at the distance L1 satisfies the safety standard.

At a position at a distance L3 far from the distance measuring device 100, the instantaneous field of view (iFOI(a), iFOI(b) and Since the iFOI(d)) overlap, it is possible to increase the intensity of the irradiation light. Similarly, at the position of the distance L4, the instantaneous field of view (iFOI(a) to iFOI(e)) of the light projecting/receiving unit 20 and the light projecting units 10a and 10b overlap in the instantaneous field of view (iFOV). , it is possible to increase the intensity of the irradiation light with which the object OB existing within the instantaneous field of view (iFOV) is irradiated. Therefore, according to the distance measuring device 100 according to the present embodiment, it is possible to observe the safety standards regarding the output of the laser beam and perform distance measurement of the object OB located far away.

A range finder 100 according to a fourth embodiment will be described. The distance measuring device 100 according to the fourth embodiment differs from the distance measuring device 100 according to the second or third embodiment in the manner in which the instantaneous light fields of the plurality of light projecting units are overlapped.

FIG. 7 shows the instantaneous field of view (iFOI) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 according to the distance from the distance measuring device 100 according to the present embodiment. It shows a cross section in a direction perpendicular to the axis AX.

The light projecting units 10 a to 10 d are spaced apart from the light projecting/receiving unit 20 in a direction perpendicular to the optical axis AX of the light projecting/receiving unit 20 . Specifically, as described in the second embodiment, the light projecting/receiving section 20 and the light projecting sections 10a to 10d are arranged at regular intervals.

The instantaneous light field (iFOI(b) to iFOI(e)) of the emitted light EL of the light projecting units 10a to 10d is the instantaneous light field (iFOI(a)) of the light projecting/receiving unit 20 and the instantaneous field of view of the light projecting/receiving unit 20 ( iFOV).

Distances L2 to L4 are the distances from the distance measuring device 100 on the optical axis AX of the light emitting/receiving section 20, and are the same as in the first embodiment. Also in the present embodiment, the light projecting/receiving unit 20 and the light projecting units 10a to 10d emit emitted light EL that satisfies the safety standards, so the description of the distance L1 is omitted.

At the position of distance L2, in the instantaneous field of view (iFOV), the instantaneous light field (iFOI(a)) of the light projecting/receiving unit 20 is the instantaneous light field (iFOI(b) to iFOI(e )) do not overlap.

At the position of the distance L2, the light projecting/receiving unit 20 can receive the reflected light RL sufficient for distance measurement of the object OB, so that distance measurement can be performed with high precision.

At the position of distance L3, in the instantaneous field of view (iFOV), the instantaneous light field (iFOI (a)) of the light projecting and receiving unit 20 and the instantaneous light field (iFOI (b) to iFOI (e) of the light projecting units 10a to 10d ) are overlapped to be included in the

For this reason, the intensity of the irradiation light applied to the object OB existing within the instantaneous field of view (iFOV) at the position of the distance L3 is doubled. Therefore, at the position of the distance L3, sufficient reflected light RL is obtained for distance measurement of the object OB.

At the position of the distance L4, in the instantaneous field of view (iFOV), the instantaneous light field (iFOI (a)) of the light projecting and receiving unit 20 and the instantaneous light field (iFOI (b) to iFOI (e) of the light projecting units 10a to 10d ) are overlapped to be included in the

For this reason, the intensity of the irradiation light applied to the object OB existing within the instantaneous field of view (iFOV) at the position of the distance L4 is doubled. Therefore, at the distance L4, sufficient reflected light RL can be obtained for distance measurement of the object OB.

As described above, the light projecting units 10a to 10d are arranged apart from the light projecting/receiving unit 20. FIG. In addition, the intensity of the emitted light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a to 10d satisfies the safety standard at the distance L1. That is, at the distance L1, the instantaneous field of view (iFOV) overlaps only the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 . Therefore, the illuminating light intensity at the distance L1 satisfies the safety standard.

At a position at a distance L3 far away from the rangefinder 100, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20, the light projecting unit 10a, and the instantaneous light projecting field (iFOI) of the light projecting unit 10c Since (a), iFOI (b) and iFOI (d)) overlap, it is possible to increase the irradiation light intensity with which the object OB existing within the instantaneous field of view (iFOV) is irradiated. Similarly, at the position of the distance L4, the instantaneous light fields (iFOI(a) to iFOI(e)) of the light projecting/receiving unit 20 and the light projecting units 10a to 10d overlap in the instantaneous field of view (iFOV). , it is possible to increase the intensity of the irradiation light with which the object OB existing within the instantaneous field of view (iFOV) is irradiated. Therefore, according to the distance measuring device 100 according to the present embodiment, it is possible to observe the safety standards regarding the output of the laser beam and perform distance measurement of the object OB located far away.

A range finder 100 according to a fifth embodiment will be described. The distance measuring device 100 according to the fifth embodiment differs from the distance measuring devices 100 according to the first to fourth embodiments in the arrangement of the light projecting unit.

FIG. 8 shows functional blocks of the distance measuring device 100 according to this embodiment. In FIG. 8, a light projecting/receiving unit 20 and light projecting units 10a to 10d are light emitting devices that each emit emitted light toward a predetermined scanning area.

The light source control unit 31 of the control unit 30 selects the light projecting units 10a to 10d that emit the emitted light EL according to the emission direction of the emitted light EL from the light projecting units 10a to 10d, and selects the selected light projecting unit. to emit emitted light EL.

FIG. 9 shows an arrangement example of the light projecting units 10a to 10d and the light projecting/receiving unit 20 of the distance measuring device 100 according to this embodiment. In FIG. 9, the light projecting units 10a to 10d are arranged point-symmetrically when viewed from the optical axis AX side of the light projecting/receiving unit 20. As shown in FIG.

That is, the distance LH1 from the light projecting/receiving unit 20 to the light projecting unit 10a is equal to the distance LH2 from the light projecting/receiving unit 20 to the light projecting unit 10c. Further, the distance LV1 from the light projecting/receiving unit 20 to the light projecting unit 10b is equal to the distance LV2 from the light projecting/receiving unit 20 to the light projecting unit 10d.

FIG. 10 shows the output light EL emitted from the light projecting/receiving unit 20 and the light projecting units 10a to 10d of the distance measuring device 100 according to the present embodiment. In FIG. 10, the light source control unit 31 selects a light projecting unit so that the time-of-flight difference is small, and emits the emitted light EL from the selected light projecting unit.

Specifically, the light source control unit 31 selects the light projecting unit having a relatively small difference in distance to the predetermined scanning region R based on the direction in which the emitted light beam EL is emitted. Choose from 10a-10d. In other words, the light source control unit 31 selects two or more light projecting units that have a relatively small time difference until the reflected light RL is received by the light projecting/receiving unit 20, based on the direction in which the emitted light EL is emitted. do.

For example, the light source control unit 31 selects the light projecting unit 10a and the light projecting unit 10d when the emitted light EL is emitted to the irradiation target point PE1 of the emitted light on the virtual plane VS, and selects the light projecting unit 10d. Emitted light EL is emitted from the portion 10a and the light projecting portion 10d.

Similarly, when the emitted light EL is emitted to the irradiation target point PE2 of the emitted light on the virtual plane VS, the light source control unit 31 selects the light projecting unit 10b and the light projecting unit 10c, and selects the selected light projecting unit. Emission light EL is emitted from the light section 10b and the light projection section 10c.

Further, when the emitted light EL is emitted to the irradiation target point PE3 of the emitted light, the light source control unit 31 selects the light projecting units 10a and 10c or the light projecting units 10b and 10d. Emission light EL is emitted from the light projection units 10a and 10c or the light projection units 10b and 10d.

Furthermore, when the emitted light EL is emitted to the irradiation target point PE4 of the emitted light on the virtual plane VS, the light source control unit 31 selects the light projecting unit 10a and the light projecting unit 10b, and selects the selected light projecting unit. Emitted light EL is emitted from the portion 10a and the light projecting portion 10b.

In this embodiment, the light source control unit 31 selects two light projecting units (light projecting unit 10a and light projecting unit 10d, or light projecting unit 10b and light projecting unit 10c) based on the direction in which the emitted light EL is emitted. ) is selected and the emitted light EL is emitted from the selected light projecting portion, the present invention is not limited to this. The light source control unit 31 selects three or more light projecting units with a small distance difference from the light projecting/receiving unit 20 and the light projecting units 10a to 10d to the predetermined scanning region R based on the direction in which the emitted light EL is emitted. may be selected, or one light projecting unit having the shortest distance from each of the light projecting units 10a to 10d to the predetermined scanning area R may be selected.

FIG. 11 macroscopically shows emitted light emitted from the distance measuring device according to the present embodiment. As shown in FIG. 11, the distance measuring device 100 continuously changes the direction of emission of the emitted light EL and emits the emitted light EL in a common direction.

Specifically, at a certain time, the light source control unit 31 selects the light projecting/receiving unit 20 and the light projecting units 10a to 10d, and emits light from the light projecting/receiving unit 20 and the light projecting units 10a to 10d in the direction D1. Emit EL.

At another time, the light source control unit 31 causes the light emitting/receiving unit 20 and the light emitting/receiving units 10a to 10d to emit the emitted light EL in the direction D1, and after a predetermined time has passed, the light emitting/receiving unit 20 and the light projecting units 10a to 10d emit emitted light EL in the direction D2.

Further, at another time, the light source control unit 31 causes the light emitting/receiving unit 20 and the light emitting/receiving units 10a to 10d to emit the emitted light EL in the direction D2, and after a predetermined time has passed, the light emitting/receiving unit 20 and the light projection units 10a to 10d emit emitted light EL in the direction D3.

12A to 12C show the instantaneous projection fields and projection fields of the light projecting/receiving unit 20 and the light projecting units 10a to 10d at a predetermined distance from the distance measuring device 100 when the emitted light EL is emitted in the direction D1. It shows a mode in which the cross section of the instantaneous visual field of the light receiving unit 20 is enlarged. Although the cross-sectional sizes of the instantaneous projection field and the instantaneous field of view change according to the distance from the distance measuring device 100, they are expressed by appropriately changing the enlargement ratio.

FIG. 12A shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 25 m from the distance measuring device 100. there is As shown in FIG. 12A, at a position at a distance of 25 m from the distance measuring device 100, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) do not overlap each other.

FIG. 12B shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 50 m from the distance measuring device 100. there is As shown in FIG. 12B, when the distance from the distance measuring device 100 is 50 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) overlap each other.

FIG. 12C shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 100 m from the distance measuring device 100. there is As shown in FIG. 12C, when the distance from the distance measuring device 100 is 100 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) overlap each other.

13A to 13C show the instantaneous light field of each of the light projecting units 10a to 10d and the moment of the light projecting/receiving unit 20 at a predetermined distance from the distance measuring device 100 when the emitted light EL is emitted in the direction D2. It shows a mode in which the cross section of the field of view is enlarged. Although the cross-sectional sizes of the instantaneous projection field and the instantaneous field of view change according to the distance from the distance measuring device 100, they are expressed by appropriately changing the enlargement ratio.

FIG. 13A shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 25 m from the distance measuring device 100. there is As shown in FIG. 13A, when the distance from the distance measuring device 100 is 25 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) are not overlapping each other.

FIG. 13B shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 50 m from the distance measuring device 100. there is As shown in FIG. 13B, when the distance from the distance measuring device 100 is 50 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) overlap each other.

FIG. 13C shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 100 m from the distance measuring device 100. there is As shown in FIG. 13C, when the distance from the distance measuring device 100 is 100 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) overlap each other.

14A to 14C show the instantaneous light field of each of the light projecting units 10a to 10d and the moment of the light projecting/receiving unit 20 at a predetermined distance from the distance measuring device 100 when the emitted light EL is emitted in the direction D3. It shows a mode in which the cross section of the field of view is enlarged. Although the cross-sectional sizes of the instantaneous projection field and the instantaneous field of view change according to the distance from the distance measuring device 100, they are expressed by appropriately changing the enlargement ratio.

FIG. 14A shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 25 m from the distance measuring device 100. there is As shown in FIG. 14A, at a position at a distance of 25 m from the distance measuring device 100, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) do not overlap each other.

FIG. 14B shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 50 m from the distance measuring device 100. there is As shown in FIG. 14B, when the distance from the distance measuring device 100 is 50 m, the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 includes the instantaneous field of view (iFOI(b)) of the light projecting units 10a to 10d. ˜iFOI(e)) overlap each other.

FIG. 14C shows an enlarged cross section of the instantaneous field of view (iFOI) of each of the light projecting units 10a to 10d and the instantaneous field of view (iFOV) of the light projecting/receiving unit 20 at a position at a distance of 100 m from the distance measuring device 100. there is As shown in FIG. 14C, at a position at a distance of 100 m from the distance measuring device 100, the instantaneous field of view (iFOV) of the light projecting and receiving unit 20 includes the instantaneous field of view (iFOI (b) ˜iFOI(e)) overlap each other.

Thus, at a position at a distance of 25 m from the distance measuring device 100 in any of the directions D1, D2, and D3, the instantaneous projection fields (iFOI(b) to iFOI(e)) in the instantaneous field of view (iFOV) do not overlap each other. That is, when the distance from the distance measuring device 100 is 25 m, the instantaneous field of view (iFOV) overlaps only the instantaneous field of view (iFOI(a)) of the light projecting/receiving unit 20 . However, at a position at a distance of 25 m from the distance measuring device 100, since the distance is short, sufficient reflected light RL can be obtained for distance measurement of the object OB. In addition, since the instantaneous projection fields (iFOI(b) to iFOI(e)) do not overlap each other at a position at a distance of 25 m from the rangefinder 100, even at a position at a distance of less than 25m from the rangefinder 100, The instantaneous flood fields do not overlap. Therefore, the distance measuring device 100 according to this embodiment satisfies the safety standards.

In addition, at a position at a distance of 50 m from the distance measuring device 100 in any of the directions D1, D2, and D3, part of the instantaneous projection field (iFOI(b) to iFOI(e)) in the instantaneous field of view (iFOV) are overlapped, the intensity of the irradiated light is increased. Therefore, at a position at a distance of 50 m from the distance measuring device 100, sufficient reflected light RL is obtained for distance measurement of the object OB.

Furthermore, at a position at a distance of 100 m from the distance measuring device 100 in any of the directions D1, D2, and D3, each of the instantaneous projection fields (iFOI(b) to iFOI(e)) in the instantaneous field of view (iFOV) are superimposed on each other, the intensity of the irradiation light is increased. Therefore, at a position at a distance of 100 m from the distance measuring device 100, sufficient reflected light RL can be obtained for distance measurement of the object OB.

As described above, the light source control unit 31 selects a light projecting unit having a small difference in distance from each light projecting unit to a predetermined scanning area from among a plurality of light projecting units, based on the emission direction of the emitted light EL. select. This makes it possible to align (or substantially align) the reception timings of the reflected light RL reflected by the object OB present in the direction in which the emitted light EL is emitted. Therefore, according to the range finder 100 according to the present embodiment, it is possible to align (or substantially align) the times of flight, and perform highly accurate ranging with simple processing.

100 Distance measuring devices 10a to 10d Light projecting unit 11 Light source 12 Light deflecting element 20 Projecting/receiving unit 21 Light source 22 Light receiving element 23 Light deflecting element 30 Distance measuring unit

Claims (8)

a plurality of light projection units for projecting emitted light;
a light-receiving unit that receives reflected light of the emitted light reflected by an object;
with
A light projecting part other than the first light projecting part among the plurality of light projecting parts is a second light projecting part arranged so as to project the emitted light on an optical axis different from the optical axis of the light receiving part. can be,
The instantaneous light field of the emitted light emitted from the second light projecting part is emitted from the first light projecting part at each position separated from the light receiving part by a predetermined distance in the optical axis direction of the light receiving part. A distance measuring device, wherein the projection field is larger than the instantaneous projection field of the emitted light. each of the plurality of light projection units has a light source for emitting the emitted light or an emitted light deflection element for changing the direction of the emitted light;
The light receiving unit includes a reflected light deflecting element that variably deflects the direction of reflected light reflected by an object from the emitted light, and a light receiving element that receives the reflected light deflected by the reflected light deflecting element. 2. The distance measuring device according to claim 1, characterized by: 2. The distance measurement according to claim 1, wherein at least one of said second light projecting portions is spaced apart from said light receiving portion in a direction perpendicular to the optical axis of said light receiving portion. Device. 4. The distance measuring device according to any one of claims 1 to 3, wherein each of the optical axes of the plurality of light projecting sections and the optical axis of the light receiving section overlap each other in the same area. 5. The distance measuring device according to claim 1, wherein each of the plurality of light projecting units emits the emitted light at different emission timings according to the emitting direction of the emitted light. 6. The method according to any one of claims 1 to 5, wherein an instantaneous field of view of said emitted light from at least one of said plurality of light projecting units is equal to an instantaneous field of view of said light receiving unit. rangefinder. The reflected light deflection element has a reflected light reflecting member that reflects the reflected light,
The emitted light deflection element has an emitted light reflecting member that reflects the emitted light,
3. The distance measuring device according to claim 2, wherein the reflected light reflecting member of each of the light receiving sections swings in conjunction with the emitted light reflecting member of the light projecting section. 8. The distance measuring device according to claim 2, wherein the reflected light deflection element is a MEMS mirror.

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