JP2022164850A - Optical device, distance measuring device and distance measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device with which it is possible to comply with safety standards regarding the intensity of laser beams and measure the distance to an object located far away with good accuracy.

SOLUTION: An optical device comprises: a plurality of light projection units, each of which includes a light source for emitting emission light and an emission light deflection element for variably deflecting the direction of the emission light, and each of which emits the emission light deflected by the emission light deflection element as irradiation light having an instant irradiation field; and a light reception unit that includes a reflected light deflection element for variably deflecting the direction of reflected light of the irradiation light having been reflected by an object and a light reception element for receiving the reflected light having been deflected by the reflected light deflection element, where the solid angle of an instant visual field is larger than the solid angle of each of the instant irradiation fields of the irradiation light.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to an optical device that emits emitted light and receives the emitted light, a distance measuring device that measures a distance to an object, and a distance measuring method.

A rangefinder including an optical device scans a target area with a laser beam, for example, and measures the distance to an object, that is, measures the distance. Such a distance measuring device includes, for example, an optical scanning unit in which a movable portion oscillates, a light source unit in which pulsed light is emitted toward the light reflecting surface of the movable unit, a light receiving unit in which reflected light of the pulsed light is received, and an object sensor. Japanese Patent Application Laid-Open No. 2002-200002 discloses an optical rangefinder including a rangefinder for measuring a distance to a target.

JP 2011-053137 A

Laser light scatters when it hits an object. Therefore, the amount of laser light received by the range finder decreases as the object irradiated with the laser light becomes farther from the range finder. 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, laser light can be harmful to humans when the power density is high. Therefore, safety standards limit the output of laser light. Therefore, when measuring the distance to an object located at a long distance, one of the problems is that the light amount of the laser light received by the rangefinder is small if the laser light complies with the safety standards.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical device that complies with safety standards regarding the intensity of laser beams and that is capable of accurately measuring the distance of a distant object. Make it one of the tasks.

The optical device according to claim 1 of the present application comprises a plurality of light projecting units each including a light source for emitting emitted light and an emitted light deflection element for deflecting the emitted light in a variable direction; a reflected light deflecting element for deflecting reflected light in a variable direction and a light receiving element for receiving the reflected light deflected by the reflected light deflecting element; and a light-receiving portion having a large solid angle of instantaneous visual field.

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; 4 is a perspective view showing an arrangement example of a light projecting unit and a light receiving unit of the distance measuring device according to the first embodiment; FIG. 4 is a conceptual diagram illustrating an instantaneous irradiation 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 first embodiment; FIG. FIG. 4 is a conceptual diagram illustrating a solid angle of an instantaneous irradiation field on a virtual plane at a predetermined distance from the distance measuring device according to the first embodiment; FIG. 2 is a conceptual diagram illustrating a solid angle of an instantaneous field of view on a virtual plane at a predetermined distance from the distance measuring device according to Example 1; 4 is a conceptual diagram illustrating an instantaneous irradiation field and an instantaneous field of view on a virtual plane at a predetermined distance from the distance measuring device according to Example 1; FIG. 4 is a processing flow showing a distance measuring method of the distance measuring device according to the first embodiment; 4 is a perspective view showing another arrangement example of the light projecting unit and the light receiving unit of the distance measuring device according to the first embodiment; FIG. FIG. 8 is an explanatory diagram showing another configuration example of the light projecting unit of the rangefinder according to the first embodiment; FIG. 11 is a block diagram showing the configuration of a distance measuring device according to Example 2; FIG. 11 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 3; FIG. 11 is a conceptual diagram illustrating an instantaneous irradiation field and an instantaneous field of view on a virtual plane at a predetermined distance from the distance measuring device according to Example 3; FIG. 12 is a perspective view showing another arrangement example of the light projecting unit and the light receiving unit of the distance measuring device according to the third embodiment; FIG. 12 is a perspective view showing another arrangement example of the light projecting unit and the light receiving unit of the distance measuring device according to the third embodiment;

An embodiment in which the optical device of the present invention is used in a distance measuring device will be described below.

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 optical deflection element 12 is a device that deflects a light beam according to a control signal. In other words, the optical deflection element 12 can variably deflect the pulsed light. The light deflection element 12 has an emitted light reflecting member including a light reflecting surface (not shown). A MEMS (Micro Electro Mechanical Systems) mirror device, a polygon mirror, or the like can be used as the light deflection element 12 . 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 used as such an optical deflector 12 .

The light deflection element 12 can reflect the pulsed light emitted from the light source 11 on the light reflecting surface and emit irradiation light toward a predetermined area to be scanned (hereinafter referred to as a scanning target area). be. Therefore, the light deflection element 12 functions as an output light deflection element.

In this way, the light projecting units 10a and 10b each emit the emitted light polarized by the light deflection element 12 toward the scanning target area as irradiation light having an instantaneous irradiation field. The illuminating light is reflected by objects present in the area to be scanned. The irradiation light reflected by the object travels toward the distance measuring device 100 as reflected light.

The light-receiving unit 20 is a light-receiving device that receives reflected light and generates a light-receiving signal, which is an electrical signal. The optical deflection element 21 is a device capable of deflecting a light beam according to a control signal. In other words, the light deflection element 21 can variably deflect the reflected light of the irradiation light reflected by the object. The light deflection element 21 has a reflected light reflecting member including a light reflecting surface (not shown). As the optical deflection element 21, a MEMS mirror device or the like can be used as in the case of the optical deflection element 12. FIG. Therefore, the optical deflection element 21 functions as a reflective optical deflection element.

The light receiving element 22 receives the reflected light deflected by the light deflection element 21 and generates a light receiving signal, which is an electrical signal. As the light receiving element 22, for example, an avalanche photodiode or the like can be adopted.

The control unit 30 controls the pulsed light emitted from the light sources 11 of the light projecting units 10a and 10b, and controls the light reflection of the light deflection elements 21 of the light receiving units 20 and the light deflection elements 12 of the light projecting units 10a and 10b. Control the angle of the face. The control unit 30 is a computer having at least a central processing unit, a main memory, and an auxiliary memory.

The light source control unit 31 controls light emission of the light sources 11 of the light projecting units 10a and 10b. Specifically, the light emission is controlled by referring to a table (not shown) that defines the light emission timing so that the light source 11 emits pulsed light.

The mirror control section 32 controls the angle of inclination of the light reflection surface of the light deflection element 12 of each of the light projection sections 10a and 10b. Specifically, the mirror control unit 32 causes the light reflection surface of the light deflection element 12 to reflect the pulsed light, and rotates the light reflection surface of the light deflection element 12 so that the scanning target area is scanned by the reflected irradiation light. to control the tilt angle of the

The mirror control section 32 controls the inclination angle of the light reflecting surface of the light deflection element 21 of the light receiving section 20 . Specifically, the mirror control unit 32 controls the direction (tilt angle) of the light reflecting surface of the light deflection element 21 of the light receiving unit 20 and the direction ( The inclination of the light reflection surface of the light deflection element 21 is controlled so that the inclination angle) is interlocked. That is, the direction of the light reflecting surface of the light deflecting element 21 of the light receiving section 20 and the direction of the light reflecting surface of the light deflecting element 12 of the light projecting sections 10a and 10b are interlocked, so that the reflected light is directed toward the light receiving element 22. proceed.

In other words, the light source control section 31 and the mirror control section 32 function as emission control means for simultaneously emitting pulsed light from each of the light projecting sections 10a and 10b. Further, the mirror control section 32 functions as a light receiving means for causing the light receiving section 20 to receive the reflected light.

A distance measurement unit 33 as a distance measurement unit calculates the distance from the distance measurement device 100 to an object within the scanning target area. In other words, the distance measurement unit 33 functions as distance measurement means for measuring the distance to the object based on the pulsed light and the reflected light.

The distance measuring unit 33 calculates the distance from the distance measuring device 100 to the object within the scanning target area based on the light receiving signal generated by the light receiving element 22 . For example, the distance measurement unit 33 calculates the distance using the time-of-flight method. Note that the calculation of the distance to the object is not limited to the time-of-flight method, and may be the phase-difference method.

Specifically, the distance measurement unit 33 determines the emission time of one pulsed light emitted by the light source 11 and the reflected light obtained by the deflection of the one pulsed light reflected by an object in the scanning target area. , the light receiving time detected by the light receiving element 22 is obtained. 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.

An irradiation surface (not shown), which is a virtual surface, is provided in the traveling direction of the irradiation light deflected by the light deflection element 12 . Note that the irradiation surface does not actually exist.

FIG. 2 is a conceptual diagram showing the operation of the light projecting system including the light projecting units 10a and 10b. In FIG. 2, the pulsed light EL1 emitted from the light source 11 is incident on the light reflecting surface MR of the light deflection element 12. As shown in FIG.

The light deflection element 12 reflects the pulsed light EL1 incident on the light reflecting surface MR. That is, the optical deflection element 12 deflects the pulsed light EL1 toward the scanning target region R as the irradiation light EL2.

The light reflecting surface MR of the light deflection element 12 is fixed to the main body so as to be swingable. Therefore, the light deflection element 12 deflects the traveling direction of the irradiation light EL2 in a desired direction within the scanning target region R by swinging the light reflection surface MR.

The irradiation light EL2 is deflected by the light deflection element 12 so that a desired trajectory is drawn on the irradiation surface VS. Further, the trajectory drawn on the irradiated 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 receiving section 20. As shown in FIG. In FIG. 3, the illumination light EL2 is reflected by an object OB present within the scanning target area R. In FIG. The irradiation light EL2 reflected by the object OB travels toward the light receiving section 20 as reflected light RL. The reflected light RL is incident on the light receiving element 22 after being reflected by the light reflecting surface MR of the light deflection element 21 of the light receiving section 20 .

The light receiving element 22 generates a light receiving signal based on the incident reflected light RL and supplies the generated light receiving signal to the controller 30 . A distance measuring unit 33 of the control unit 30 measures the distance to the object OB based on the time when the pulsed light EL1 is emitted and the time when the reflected light RL is received.

FIG. 4 shows an arrangement example of the light projecting units 10a and 10b and the light receiving unit 20 of the distance measuring device 100 according to this embodiment. As shown in FIG. 4, the light projecting units 10a and 10b are arranged in a row on the substrate 40 so as to sandwich the light receiving unit 20 therebetween.

Further, the light projecting units 10a and 10b are arranged at equal distances to the light receiving unit 20. As shown in FIG. Specifically, the distance LH1 from the light receiving unit 20 to the light projecting unit 10a is equal to the distance LH2 from the light receiving unit 20 to the light projecting unit 10b.

FIG. 5 shows aspects of the instantaneous field of view (iFOI) of the light projecting units 10 and 10b and the instantaneous field of view (iFOV) of the light receiving unit 20. As shown in FIG. Incidentally, the dashed arrow in the figure indicates the traveling direction of the irradiation light EL2.

Specifically, FIG. 5 shows the instantaneous field of view (iFOI) of the light projecting units 10a and 10b and the instantaneous field of view (iFOV) of the light receiving unit 20 with respect to the traveling direction of the irradiation light EL2 indicated by the dashed arrows in the figure. A cross section in the vertical direction is shown according to the distance from the distance measuring device 100. FIG.

Here, the instantaneous field of view (iFOI) is the area irradiated with the emitted light EL at the instant of interest. For example, the instantaneous field of view (iFOI) is each angular range in which the shape of the light source (not shown) is projected by the projection lenses (not shown) of the projection units 10a and 10b, or the sum of each angle range. The instantaneous field of view (iFOV) is an angular range that the light-receiving lens of the light-receiving unit 20 sees the light-receiving surface of the light-receiving unit 20 .

The two-dot chain lines in the drawing indicate the instantaneous irradiation field (iFOI(a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI(b)) of the light projecting unit 10b. Also, the dashed-dotted line in the drawing indicates the instantaneous field of view (iFOV) of the light receiving section 20 .

Each of the light projecting units 10a and 10b emits the irradiation light EL2 with an output that satisfies safety standards. A safety standard is established based on the intensity of light at a predetermined distance from the rangefinder 100 . The safety standard is defined, for example, based on the light intensity at 100 mm from the distance measuring device 100 . Also, the instantaneous irradiation field (iFOI(a), iFOI(b)) of the emitted light EL emitted from the light projecting unit 10a and the light projecting unit 10b is smaller than the instantaneous field of view (iFOV).

The positional relationship between the instantaneous irradiation fields (iFOI(a), iFOI(b)) within the instantaneous field of view (iFOV) changes according to the distance from the rangefinder 100 . Specifically, as the distance from the range finder 100 increases, the instantaneous irradiation fields (iFOI(a), iFOI(b)) become closer to each other and touch each other at a predetermined distance from the range finder 100 .

Distances L1 to L4 are distances from the distance measuring device 100. FIG. For example, the distances L1 to L4 are distances from the light receiving section 20. FIG. Further, the distances L1 to L4 may be distances from the light projecting section 10a or the light projecting section 10b.

A distance L1 is a distance from the distance measuring device 100 defined by safety standards. At the position of the distance L1, the instantaneous field of view (iFOI(a)) of the light projecting unit 10a and the instantaneous field of view (iFOI(b)) of the light projecting unit 10b are arranged outside the instantaneous field of view (iFOV) of the light receiving unit 20. It is

Therefore, the intensity of the irradiation light EL2 emitted from the light projection units 10a and 10b at the position of the distance L1 satisfies the safety standard. At the position of the distance L1, either one or both of the instantaneous irradiation field (iFOI (a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI (b)) of the light projecting unit 10b It may be arranged inside the instantaneous field of view (iFOV) of 20. In this case, the output of the illuminating light EL2 may be appropriately adjusted so as to meet the safety standards at the position of the distance L1.

Distance L2 is the distance from rangefinder 100 and is longer than distance L1. Distance L2 is, for example, 50 m from rangefinder 100 . At the position of the distance L2, part of the instantaneous irradiation field (iFOI (a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI (b) of the light projecting unit 10b is inside the instantaneous field of view (iFOV) of the light receiving unit 20 Therefore, when the object OB exists at the position of the distance L2, the light receiving section 20 can obtain the reflected light RL sufficient for measuring the distance of the object OB. 100 is capable of ranging an object OB existing at a distance greater than the distance L2.

Distance L3 is the distance from rangefinder 100 and is longer than distance L2. Distance L3 is, for example, 100 m from rangefinder 100 . At the position of distance L3, part of the instantaneous field of view (iFOI(a)) of the light projecting part 10a and the instantaneous field of view (iFOI(b) of the light projecting part 10b) is inside the instantaneous field of view (iFOV) of the light receiving part 20. is distributed to

In addition, the instantaneous irradiation field (iFOI(a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI(b) of the light projecting unit 10b arranged inside the instantaneous field of view (iFOV) of the light receiving unit 20 at the distance L3 The area ratio is greater than the distance L2.

Therefore, when the object OB exists at the position of the distance L3, the light receiving unit 20 can obtain sufficient reflected light RL for distance measurement of the object OB. Therefore, the distance measuring apparatus 100 can perform distance measurement in a state where the density of the instantaneous field of view (iFOI) arranged in the instantaneous field of view (iFOV) is higher than when the object OB exists at the distance L2. .

Distance L4 is the distance from rangefinder 100 and is longer than distance L3. Distance L4 is, for example, 200 m from rangefinder 100 .

At the position of the distance L4, the instantaneous irradiation field (iFOI(a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI(b)) of the light projecting unit 10b are arranged inside the instantaneous field of view (iFOV) of the light receiving unit 20. ing.

That is, the instantaneous irradiation field (iFOI(a)) of the light projecting unit 10a and the instantaneous irradiation field (iFOI(b) of the light projecting unit 10b arranged inside the instantaneous field of view (iFOV) of the light receiving unit 20 at the distance L4 The area ratio is greater than the distance L3.

Therefore, when the object OB exists at the position of the distance L4, the light receiving unit 20 can obtain sufficient reflected light RL for measuring the distance of the object OB. Therefore, the distance measuring apparatus 100 can perform distance measurement in a state where the density of the instantaneous field of view (iFOI) arranged in the instantaneous field of view (iFOV) is higher than when the object OB exists at the distance L3. .

FIG. 6A shows the instantaneous irradiation field (iFOI(a), iFOI(b)) on the irradiation plane VS at the distance L4 in FIG. In FIG. 6A, an irradiation surface VS is arranged at a position a predetermined distance (r) from the light source 11 . Instantaneous irradiation fields (iFOI(a), iFOI(b)) of the light sources 11 of the light projection units 10a, 10b are shown on the irradiation surface VS.

An instantaneous irradiation field (iFOI(a), iFOI(b)) on the irradiation surface VS is shown in a rectangular shape. Note that the instantaneous irradiation field (iFOI(a), iFOI(b)) on the irradiation surface VS is not limited to a rectangular shape, and the light source 11 may be configured to have, for example, a circular or elliptical shape.

Here, a solid angle is defined by a conical surface formed by moving half straight lines from the same point in space. The solid angle can be represented by the size of the area cut by the cone from a sphere with a radius of 1 centered at the point.

In this embodiment, when the same point in space is the light source 11, the solid angle at which the light source 11 sees the instantaneous irradiation field (iFOI(a), iFOI(b)) is the instantaneous irradiation field (iFOI (a), iFOI (b)). A line connecting the center CI of the instantaneous irradiation field (iFOI(a), iFOI(b)) and the light source 11 is defined as an axis AX1.

FIG. 6B shows the instantaneous field of view (iFOV) at the illumination plane VS at distance L4 in FIG. In FIG. 6B, the irradiation surface VS is arranged at a predetermined distance (r) from the light receiving element 22 . That is, the distance from the light source 11 to the irradiation surface VS in FIG. 6A is equal to the distance from the light receiving element 22 to the irradiation surface VS.

The instantaneous field of view (iFOV) of the receiver 20 is shown on the illumination plane VS. The instantaneous field of view (iFOV) on the illuminated surface VS is shown as a rectangle. Note that the instantaneous field of view (iFOV) on the irradiation surface VS is not limited to a rectangular shape, and the light receiving element 22 of the light receiving unit 20 may be configured to have a circular or elliptical shape, for example.

Also, the instantaneous irradiation fields (iFOI(a), iFOI(b)) shown in FIG. 6A are shown inside the instantaneous field of view (iFOV) on the irradiation surface VS. The instantaneous field of view (iFOV) on the illuminated surface VS is larger than the instantaneous field of view (iFOI(a), iFOI(b)).

In this embodiment, when the light receiving element 22 is the same point in space, the solid angle at which the light receiving element 22 sees the instantaneous field of view (iFOV) is represented by the instantaneous field of view (iFOV) on the irradiation surface VS.

Therefore, the solid angle through which the light source 11 looks into the instantaneous field of view (iFOI(a), iFOI(b)) is smaller than the solid angle through which the light receiving element 22 looks into the instantaneous field of view (iFOV). In other words, the solid angle through which the light receiving element 22 views the instantaneous field of view (iFOV) is larger than the solid angle through which the light source 11 views the instantaneous irradiation fields (iFOI(a), iFOI(b)). A line connecting the center CV of the instantaneous field of view (iFOV) and the light receiving element 22 is defined as an axis AX2.

FIG. 6C shows the instantaneous field of view (iFOI(a), iFOI(b)) and the instantaneous field of view (iFOV) at the illumination plane VS located at distance L4. Note that the instantaneous irradiation field (iFOI(a), iFOI(b)) and the instantaneous field of view (iFOV) on the irradiation surface VS are shown in a rectangular shape.

As shown in FIG. 6C, on the irradiation surface VS located at the distance L4, the irradiation region RI is formed by the instantaneous irradiation fields (iFOI(a), iFOI(b)) of the light projection units 10a, 10b. . The irradiation area RI is an area illuminated by each of the light projection units 10a and 10b.

The irradiation area RI is, for example, an area having at least half the brightness of the irradiation light EL2 at the center of the area irradiated with the irradiation light EL2 on the irradiation surface VS located at the distance L4.

The field of view RV is formed by the instantaneous field of view (iFOV) of the receiver 20 on the illumination plane VS located at the distance L4. The illuminated area RI includes the entire viewing area RV in the illuminated plane VS located at the distance L4.

The position on the scanning area R where the irradiation area RI includes the entire instantaneous visual field RV, that is, the distance from the distance measuring device 100 can be adjusted as appropriate. For example, the distance from the range finder 100 may be a distance closer to the range finder 100 than the distance L4, such as the distance L2 or the distance L3, or a distance farther to the range finder 100 than the distance L4. may be

FIG. 7 is a processing flow showing a distance measurement method of the distance measurement device 100. As shown in FIG. As shown in FIG. 7, the control unit 30 simultaneously emits the irradiation light EL2 from each of the light projecting units 10a and 10b (step S01). In other words, the distance measuring device 100 simultaneously emits the illumination light EL2 from each of the light projection units 10a and 10b. Specifically, the control unit 30 causes the light source 11 of each of the light projecting units 10a and 10b to emit the pulsed light EL1. The control unit 30 deflects the pulsed light EL1 by the optical deflector 12 of each of the light projecting units 10a and 10b. As a result, the irradiation light EL2 is simultaneously emitted from each of the light projection units 10a and 10b.

Next, the control unit 30 causes the light receiving unit 20 to receive the reflected light RL which is the reflected light RL of the irradiation light EL2 reflected by the object OB (step S02). In other words, the rangefinder 100 receives the reflected light RL with the light receiving unit 20 having an instantaneous field of view (iFOV). Specifically, the control section 30 causes the light deflection element 21 of the light receiving section 20 to deflect the reflected light RL, and causes the light receiving element 22 to receive the deflected reflected light RL.

The controller 30 measures the distance to the object OB based on the pulsed light EL1 and the reflected light RL (step S03). In other words, the distance measuring device 100 measures the distance to the object OB based on the pulsed light EL1 and the reflected light RL.

Specifically, the control unit 30 acquires the emission time of one pulsed light emitted by the light source 11 and the light receiving time when the light receiving element 22 detects the one pulsed light as the reflected light RL. The control unit 30 calculates the distance between the distance measuring device 100 and the object OB based on the time difference between the emission time and the light reception time.

As described above, the intensity of each emitted light beam EL emitted from the light receiving unit 20 and the light emitting units 10a and 10b satisfies the safety standard at the position of the distance L1.

Further, after a distance L2, which is longer than the distance L1 from the distance measuring device 100, the instantaneous irradiation fields (iFOI(a), iFOI(b)) of the light projecting units 10a and 10b are within the instantaneous field of view (iFOV). are distributed. Further, as the distance from the distance measuring device 100 increases, the proportion of the instantaneous field of view (iFOI(a), iFOI(b)) within the instantaneous field of view (iFOV) increases. 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 laser light and accurately measure the distance to an object OB located far away.

The information processing performed by the distance measuring device 100 of the present invention can be executed by a program for executing the information processing performed by the distance measuring device 100 in the above embodiment. The program for executing the information processing method of the present invention is recorded on a computer-readable recording medium and can be suitably used. For example, the distance measuring device 100 of the present invention can read the program of the present invention from a recording medium and execute the program of the present invention.

Further, the arrangement of the light projecting units 10a and 10b is not limited to the arrangement example of this embodiment. For example, as shown in FIG. They may be arranged in rows on the substrate 40 in a direction perpendicular to the arrangement direction of the parts 10a and 10b.

When the light projecting units 10a and 10b are arranged in this way, it is preferable that the light projecting units 10a and 10b are arranged at equal distances to the light receiving unit 20 as described with reference to FIG. Specifically, the distance LV1 from the light receiving unit 20 to the light projecting unit 10a should be equal to the distance LV2 from the light receiving unit 20 to the light projecting unit 10b.

Further, the instantaneous irradiation field (iFOI(a), iFOI(b)) may be adjusted by shielding the irradiation light EL2 emitted from the light source 11 . FIG. 9 shows a configuration example in which the light projecting units 10a and 10b are provided with shielding members SC. As shown in FIG. 9, the shielding member SC is provided between the light source 11 and the light deflection element 12. As shown in FIG. The shielding member SC partially shields the pulsed light EL1. Therefore, the pulsed light EL1 is partly shielded by the shielding member SC and enters the light reflection surface MR of the light deflection element 12 .

By adjusting the instantaneous irradiation field (iFOI(a), iFOI(b)) with the shield member SC, it becomes easy to set the output of the light source 11 that emits the irradiation light EL2. For example, when cutting half of the pulsed light EL1 emitted from the light source 11, this can be achieved by shielding half of the pulsed light EL1 with the shielding member SC. Therefore, the power of the light source 11 that emits pulsed light can be easily set with a simple configuration without requiring a configuration for controlling the current supplied to the light source 11 .

In Example 1, the light receiving section 20 is configured to have a function as a light receiving section. However, the light receiving section may be configured to have not only the function as the light receiving section but also the function as the light projecting section. The same reference numerals are assigned to the same components as the rangefinder 100 according to the first embodiment, and the description thereof is omitted.

FIG. 10 shows functional blocks of a distance measuring device 100 according to the second embodiment. As shown in FIG. 10, the light source 51 of the light projecting/receiving unit 50 is a light emitting device that emits emitted light. The light source 51 has the same configuration as the light source 11 of the light projection units 10a and 10b.

The optical deflection element 52 is a device that deflects a light beam according to a control signal. In other words, the optical deflection element 52 can variably deflect the direction of the pulsed light EL1 and the direction of the reflected light RL. The light deflection element 52 has an emitted light reflecting member including a light reflecting surface (not shown).

As for the optical deflection element 52, a MEMS mirror device or the like can be used as in the case of the optical deflection element 12. FIG. The light deflection element 52 can reflect the pulsed light on the light reflecting surface to emit the irradiation light EL2 toward the scanning target region R, and can deflect the reflected light toward the light receiving element 53 . Therefore, the light deflection element 52 functions as an emitted light deflection element and a reflected light deflection element.

A beam splitter (not shown) may be provided between the light source 51 and the optical deflection element 52 to separate the pulsed light EL1 and the reflected light RL.

The light receiving element 53 receives the reflected light RL deflected by the light deflection element 52 and generates a light receiving signal, which is an electrical signal. For example, an avalanche photodiode or the like can be used as the light receiving element 53 .

Thus, the light projecting/receiving section 50 has a function of a light projecting section and a function of a light receiving section. Therefore, the instantaneous field of view (iFOI) axis AX1 of the light projecting/receiving unit 50 coincides with the instantaneous field of view (iFOV) axis AX2.

As described above, according to the distance measuring device 100 of the present embodiment, similarly to the distance measuring device 100 of the first embodiment, the safety standards regarding the output of the laser beam are complied with, and the distance measurement of the object OB located far away is performed. can be performed with high accuracy. Further, since the axis AX1 of the instantaneous field of view (iFOI) of the light projecting/receiving unit 50 coincides with the axis AX2 of the instantaneous field of view (iFOV), the distance from the distance measuring device 100 is shorter than the distance L2, for example. Even if the object OB exists in the distance, it is possible to measure the distance of the object OB with high accuracy.

In the distance measuring device 100 according to the first embodiment, the light projecting section 10a and the light projecting section 10b are arranged at different positions in the instantaneous field of view (iFOV). However, the light projecting section 10a and the light projecting section 10b may be arranged to overlap each other in the instantaneous field of view (iFOV). The same reference numerals are assigned to the same components as the rangefinder 100 according to the first embodiment, and the description thereof is omitted.

FIG. 11 shows an arrangement example of the light projecting unit 10 and the light receiving unit 20 of the distance measuring device 100 according to the third embodiment. As shown in FIG. 11, the light projecting sections 10a to 10d are arranged in a row on the substrate 40 so as to sandwich the light receiving section 20 therebetween. Specifically, the light projecting sections 10a to 10d are arranged at the end of the row, and the light projecting sections 10b and 10c are arranged therebetween. A light receiving section 20 is arranged between the light projecting sections 10b and 10c.

Further, the distance between the light projecting unit 10a and the light projecting unit 10b, the distance between the light projecting unit 10b and the light receiving unit 20, the distance between the light receiving unit 20 and the light projecting unit 10c, and the light projecting unit 10c and the light projecting portion 10d are arranged at the same distance.

FIG. 12 shows the instantaneous field of view (iFOI(a) to iFOI(d)) and the instantaneous field of view (iFOV) in the illumination plane VS located at the distance L4. Note that the instantaneous irradiation field (iFOI(a) to iFOI(d)) and the instantaneous field of view (iFOV) on the irradiation surface VS are shown in a rectangular shape.

As shown in FIG. 12, on the irradiation surface VS located at the distance L4, the irradiation region RI is formed by the instantaneous irradiation fields (iFOI(a) to iFOI(d)) of the light projection units 10a to 10d. .

Specifically, the illumination area RI is an area illuminated by each of the light projection units 10a to 10d on the illumination surface VS. The illumination area RI includes the entire viewing area RV.

The instantaneous irradiation field (iFOI(a), iFOI(b)) on the irradiation surface VS of each of the pair of light projection units 10a and 10b among the light projection units 10a to 10d is the instantaneous field of view (iFOV) on the irradiation surface VS. overlapping each other on top. In addition, the instantaneous irradiation field (iFOI(c), iFOI(d)) on the irradiation surface VS of each of the pair of light projection units 10c and 10d among the light projection units 10a to 10d is the instantaneous field of view ( iFOV), they overlap each other at a distance L4.

The field of view RV is formed by the instantaneous field of view (iFOV) of the receiver 20 on the illumination plane VS located at the distance L4. The illuminated area RI includes the entire viewing area RV in the illuminated plane VS located at the distance L4.

Here, the sum of the intensities of the emitted light beams EL emitted from the light projecting units 10a to 10d and irradiated within the instantaneous field of view (iFOV) at the distance from the distance measuring device 100 is defined as the distance measurement. Let it be the intensity of the illuminating light at the distance from the device 100 .

In this way, the instantaneous irradiation fields (iFOI(a), iFOI(b)) on the irradiation surface VS of each of the light projecting units 10a and 10b overlap each other on the instantaneous field of view (iFOV) on the irradiation surface VS. , the irradiation light intensity can be increased in the region where the instantaneous irradiation fields (iFOI(a), iFOI(b)) overlap each other. Similarly, the instantaneous irradiation fields (iFOI(c), iFOI(d)) on the irradiation surface VS of each of the light projection units 10c and 10d overlap each other on the instantaneous field of view (iFOV) on the irradiation surface VS. The irradiation light intensity can be increased in the region where the instantaneous irradiation fields (iFOI(c), iFOI(d)) overlap each other. Therefore, it is possible to increase the amount of reflected light RL received by the light receiving unit 20 .

As described above, according to the distance measuring device 100 of the present embodiment, similarly to the distance measuring device 100 of the first embodiment, the safety standards regarding the output of the laser beam are complied with, and the distance measurement of the object OB located far away is performed. can be performed with high accuracy. In particular, since it is possible to increase the amount of reflected light RL received by the light receiving unit 20, it is possible to accurately measure the distance to the object OB.

The arrangement of the light projection units 10a and 10b is not limited to the arrangement example of this embodiment. For example, as shown in FIG. They may be arranged in rows in a direction perpendicular to the arrangement direction of the parts 10a to 10d.

When the light projecting units 10a to 10d are arranged in this way, as described with reference to FIG. , the distance between the light receiving section 20 and the light projecting section 10c, and the distance between the light projecting section 10c and the light projecting section 10d are preferably arranged equally.

Further, the light projecting units 10a to 10d may be arranged on the substrate 40 at positions equidistant from the light receiving unit 20. FIG. FIG. 14 shows an arrangement example of the light projecting units of the distance measuring device 100 according to the modification. As shown in FIG. 14, the distance LH1 from the light receiving section 20 to the light projecting section 10a is equal to the distance LH2 from the light receiving section 20 to the light projecting section 10c. Further, the distance LV1 from the light receiving section 20 to the light projecting section 10b is equal to the distance LV2 from the light receiving section 20 to the light projecting section 10d. Furthermore, the distances LV1, LV2, LH1 and LH2 are equal to each other.

The light receiving unit 20 of this embodiment may be implemented by the light projecting and receiving unit 50 described in the second embodiment.

100 Distance measuring devices 10a to 10d Light projecting unit 11 Light source 12 Light deflecting element 20 Light projecting/receiving unit 21 Light source 22 Light receiving element 23 Light deflecting element 30 Control unit 40 Distance measuring unit iFOI Instantaneous irradiation field iFOV Instantaneous field of view OB Object VS Irradiation surface

Claims (1)

each including a light source for emitting output light and an output light deflection element for variably deflecting said output light, and each said output light polarized by said output light deflection element as illumination light having an instantaneous illumination field. a plurality of light projecting units that emit light;
said illuminating light includes a reflected light deflecting element for variably deflecting reflected light reflected by an object and a light receiving element for receiving said reflected light deflected by said reflected light deflecting element, and said moment of each of said illuminating light a light-receiving part with a larger solid angle of the instantaneous field of view than the solid angle of the irradiation field;
An optical device comprising:

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