JP6522896B2 - Optical scanning device and laser radar device - Google Patents

Description

  The present invention relates to an optical scanning device that controls an optical system, and a laser radar device equipped with the optical scanning device.

  Conventionally, a light emitting unit that emits laser light, a deflecting unit that deflects laser light from the light emitting unit to a specified angular range by an optical system (polygon mirror) that rotates at a defined rotational speed, and a laser at the light emitting unit There is known an optical scanning device provided with a control unit that controls light emission start timing of light (see Patent Document 1).

  The irradiation of the laser light to the specified angular range by the optical scanning device is realized by emitting the laser light at the timing that the specific part of the optical system rotating at the specified rotational speed can be irradiated with the laser light. . For this reason, in order to improve the irradiation accuracy of the laser beam to the specified angle range, it is important to detect the position (rotational angle) of the optical system.

  Therefore, in the optical scanning device described in Patent Document 1, the position detection light receiving unit having a predetermined shape is disposed at both ends of the scanning range. Then, the position (rotational angle) of the optical system is detected based on the light reception level detected by the position detection light receiving unit.

JP 2005-37575 A

  By the way, a laser radar device equipped with an optical scanning device and mounted in a car has been proposed. In the optical scanning device used in this laser radar device, it is conceivable to apply the technique described in Patent Document 1 as a technique for detecting the position (rotational angle) of the optical system.

  However, in an automobile equipped with the laser radar device, the temperature environment is wide from low temperature to high temperature, and disturbance such as vibration is also large. Therefore, the distance between the two position detection light receiving units changes due to expansion or contraction due to heat, or the arrangement position itself of the position detection light receiving unit changes due to the vibration of the vehicle.

  As described above, when the arrangement interval and the arrangement position of the position detection light receiving unit change, the accuracy of position detection of the optical system decreases. In order to prevent this, the structure which suppresses expansion and contraction by change of heat, and the structure which absorbs vibration are needed, and the subject that equipment composition becomes complicated arises.

  That is, in the prior art, there is a problem that it is difficult to simplify the device configuration while improving the detection accuracy of the position of the optical system in the optical scanning device mounted on a car.

  Therefore, the present invention has an object of simplifying the device configuration while improving the detection accuracy of the position of the optical system in an optical scanning device mounted on an automobile.

The present invention, which was made to achieve the above object, relates to an optical scanning device mounted on a vehicle.
The optical scanning device according to the present invention comprises light emitting means (21, 71), deflection means (24, 25, 72, 74), first light receiving means (60), and position detection means (42, S140, S230). Equipped with

The light emitting means emits a laser beam.
The deflection means are driven in a defined drive manner which is a defined drive manner. When the laser beam from the light emitting means is irradiated to the prescribed site which is the defined site of the deflecting means, the deflecting means radiates the laser beam to an appropriate angle range. Further, when the laser beam from the light emitting means is irradiated to the scattering portion which is a portion of the deflection means different from the prescribed portion, the deflection means scatters the laser beam.

  The first light receiving means receives the laser light scattered by the deflecting means. The position detection means detects that the scattering portion is positioned at the reference position when the light reception intensity becomes equal to or greater than a predetermined threshold as a result of light reception by the first light reception means.

  In such an optical scanning device, when the defined part of the deflection means driven in the defined drive mode is irradiated with the laser light from the light emitting means, the laser light is irradiated to an appropriate angle range. On the other hand, when the laser beam from the light emitting means is irradiated to the scattering portion of the deflecting means driven in the defined drive mode, the laser beam is scattered.

  That is, when the laser light is irradiated to the prescribed part, since the laser light is irradiated within the proper angle range, the intensity of the laser light outside the proper angle range is reduced. On the other hand, when the laser beam is irradiated to the scattering part, the laser beam is scattered, so the intensity of the laser beam outside the proper angle range becomes large.

  In other words, the intensity of light received by the first light receiving means is larger when the scattering portion is irradiated with the laser than in the case where the irradiation portion is irradiated with the laser. Therefore, according to the optical scanning device of the present invention, when the light receiving intensity becomes equal to or greater than a predetermined threshold as a result of light reception by the first light receiving unit, it can be detected that the scattering portion is positioned at the reference position.

  Moreover, the position detection of the deflecting means in the optical scanning device of the present invention is realized by irradiating the deflecting means with laser light and receiving the light scattered by the laser light by the first light receiving means. Therefore, according to the optical scanning device of the present invention, the position of the deflection means can be detected without complicating the device configuration.

In other words, according to the present invention, in the optical scanning device mounted on a car, the device configuration can be simplified while improving the detection accuracy of the position of the optical system.
Furthermore, the optical scanning device in the present invention may include light emission control means (42, S150 to S170, S220). In the light emission control means in the present invention, the light emission timing of the laser light in the light emission means may be controlled in accordance with the detection result of the position detection means.

According to such an optical scanning device, laser light can be emitted at an appropriate light emission timing.
Further, the present invention may be configured as a laser radar device provided with an optical scanning device, a second light receiving unit (30), and an object detecting unit (42, S180, S260).

In this case, the optical scanning device is a device according to any one of claims 1 to 6.
The second light receiving means receives the reflected light of the laser light from the appropriate angle range. The object detection means emits laser light by the light emission means, and detects an object reflecting the laser light based on the result of receiving the reflected light by the second light reception means.

According to such a laser radar device, it is possible to improve the detection accuracy of the position of the object which has reflected the laser light.
In addition, the code | symbol in the parentheses described in the column of "claim" and the "means for solving the problem" shows the correspondence with the specific means as described in the embodiment mentioned later as one mode. It does not limit the technical scope of the present invention.

It is a figure which shows schematic structure of the laser radar apparatus with which this invention was applied. It is an explanatory view explaining details of a rotation polygon mirror. It is explanatory drawing explaining arrangement | positioning of a scattered light light-receiving part. It is a flowchart which shows the process sequence of the ranging process in 1st Embodiment. It is a flowchart which shows the process sequence of the ranging process in 2nd Embodiment. It is explanatory drawing which shows the modification of the light emission part in this invention.

Embodiments of the present invention will be described below with reference to the drawings.
First Embodiment
<Laser radar device>
The laser radar device 10 shown in FIG. 1 is mounted on an automobile. The laser radar device 10 outputs (irradiates) laser light as a search wave to a proper angle range, and detects a target present in the proper angle range.

The laser radar device 10 includes a light emitting unit 20, a light receiving unit 30, a detection circuit 40, a control unit 42, and a scattered light receiving unit 60.
The light emitting unit 20 emits laser light whose signal level changes in a pulse shape in accordance with the light emission signal Es from the control unit 42, and emits the laser light in an appropriate angle range.

  In order to realize this, the light emitting unit 20 includes a laser diode (LD) 21, an LD drive circuit 22, an optical element 23, a rotating polygon mirror 24, a scanner mechanism unit 25, and an SC drive circuit 26. ing.

  The laser diode 21 emits a laser beam. The laser diode 21 is disposed so as to irradiate the laser light emitted by the laser diode 21 itself in a predetermined irradiation range.

  The LD drive circuit 22 causes the LD 21 to emit a laser beam whose output level along the time axis changes in a pulse shape in accordance with the light emission signal Es from the control unit 42. The optical element 23 includes a light emitting lens that determines the beam width of the laser light emitted by the LD 21. However, the light emitting lens included in the optical element 23 is configured to set the beam width of the laser light emitted by the LD 21 as the irradiation range.

The rotary polygon mirror 24 is a mirror (polygon mirror) in which the tilt angles of the plurality of surfaces are different. The rotary polygon mirror 24 is disposed in an irradiation range to which the laser light from the LD 21 is irradiated.
The scanner mechanism 25 rotatably supports the rotary polygon mirror 24. The SC drive circuit 26 drives the scanner mechanism 25 (and hence the rotary polygon mirror 24) at a prescribed rotation speed defined in advance in accordance with the SC drive signal from the control unit 42.

  In such a light emitting unit 20, the rotary polygon mirror 24 rotates at a specified rotation speed. Then, in the light emitting unit 20, the laser light reflected by the rotary polygon mirror 24 which is in rotational movement is irradiated to the appropriate angle range by the laser light reflected by the rotary polygon mirror 24. Furthermore, since the light emission intensity of the laser light irradiated to the rotary polygon mirror 24 changes in a pulse shape, the light emitting unit 20 divides each appropriate angle range into individual angle ranges (hereinafter referred to as “irradiation angle θ”) To the laser light.

That is, the light emitting unit 20 of the present embodiment is configured as a so-called scanning type laser beam irradiation device.
Next, the light receiving unit 30 receives the reflected light generated by reflecting the laser light, and outputs a light reception signal Rs. Specifically, the light receiving unit 30 in the present embodiment includes a light receiving lens 31, a light receiving element (PD) 32, and an amplifier 33.

  The light receiving lens 31 condenses the reflected light. The light receiving element 32 receives the reflected light through the light receiving lens 31, and generates a light receiving signal Rs having a signal intensity corresponding to the light receiving intensity. The amplifier 33 amplifies the light reception signal Rs from the light reception element 32.

  The detection circuit 40 measures the time from when the light emitting unit 20 emits laser light to when the light receiving unit 30 receives the reflected light, and measures the light receiving intensity of the reflected light at the light receiving unit 30 to generate measurement data. Do. Furthermore, the detection circuit 40 outputs the generated measurement data to the control unit 42 based on the request from the control unit 42.

  The detection circuit 40 measures the phase difference between the light emission signal Es from the control unit 42 and the light reception signal Rs from the light reception unit 30 whose signal level is equal to or higher than a predetermined threshold (that is, the round trip time to the reflector) A distance (hereinafter referred to as a detection distance) R to an object that has reflected the laser light is derived. At the same time, the detection circuit 40 specifies the irradiation angle θ irradiated with the laser light, that is, the azimuth in which the object reflecting the laser light is present.

The measurement data generated by the detection circuit 40 corresponds the detection distance R to the irradiation angle θ and the signal level of the light reception signal Rs.
The control unit 42 stores the processing program and data that need to hold the stored content even when the power is cut off, the RAM 46 that temporarily stores the processing program and data, and the processing stored in the ROM 44 and the RAM 46 The computer is mainly configured of a known computer having at least a CPU 48 that executes various processes in accordance with a program.

The ROM 44 of the control unit 42 stores a processing program for the control unit 42 to execute distance measurement processing that outputs the light emission signal Es and generates target information based on the measurement data generated by the detection circuit 40. It is done. Target information is data including the result of recognition of a target assumed to be the same object as a front object, the shape of a front object (cluster), the distance to the front object, and the direction (ie, relative position). is there.
<Details of rotating polygon>
Next, details of the rotary polygon mirror 24 in the present embodiment will be described.

  As shown in FIG. 2A, each surface constituting the rotary polygon mirror 24 deflects the laser beam from the laser diode 21 to the irradiation range to an appropriate angle range. That is, each surface constituting the rotary polygon mirror 24 functions as a prescribed portion (hereinafter referred to as “irradiation unit”) described in the claims. The rotary polygon mirror 24 in the present embodiment has, for example, three or more surfaces (hereinafter, referred to as deflection surfaces) 50 that function as an irradiation unit. The number of deflection surfaces 50 may be six or four.

  Further, as shown in FIG. 2B, in the rotary polygon mirror 24, an end (hereinafter referred to as a scattering portion) 52 where the deflecting surfaces 50 adjacent to each other are connected is a laser beam from the LD 21 to the irradiation range. Scatter it. The scattering portion 52 may have a structure in which the end where the adjacent deflection surfaces 50 are connected is chamfered, or may include the periphery of the end where the adjacent deflection surfaces 50 are connected.

  The size of the scattering portion 52 is the rotation speed R [rpm] per unit time of the rotary polygon mirror 24, the light emission interval T [s] of the laser light, and the size D [deg of the irradiation range to which the laser light is irradiated. It should be decided based on]. Specifically, the time during which the scattering portion 52 is located within the irradiation range is D / 60R [s], and the number of times of laser light emission within this time is D / 60 RT [times]. For this reason, the size of the scattering portion 52 is such that the laser beam to the irradiation range is emitted at least once while the scattering portion 52 rotating at the specified rotational speed is positioned within the irradiation range. You can decide

  The scattered light receiving unit 60 is a known light detector that outputs a signal according to the received light intensity. The scattered light receiving unit 60 of the present embodiment is disposed at a position where at least a part of the laser light scattered by the scattering unit 52 of the rotating polygon mirror 24 deviates from the light path from the rotating polygon mirror 24 to the appropriate angle range. Be done. Specifically, the scattered light receiving unit 60 may be disposed above the line connecting the upper bottom surface of the rotary polygon mirror 24 and the upper end of the appropriate angle range, or the lower bottom surface of the rotary polygon mirror 24 And the lower end of the appropriate angle range.

  Here, FIG. 3 is a view schematically showing the laser light scattered by the scattering section 52. As shown in FIG. That is, FIG. 3A is a view showing the state of the laser light scattered by the scattering section 52 from above with respect to the scanning direction of the laser light, and FIG. 3B is a rotation axis of the laser light. On the other hand, it is the figure which showed the mode of the laser beam scattered in the scattering part 52 from the side.

That is, when the laser beam is irradiated to the deflection surface 50 of the rotary polygon mirror 24 which rotates at the specified rotational speed, the laser beam reflected by the rotary polygon mirror 24 is irradiated to the appropriate angle range.
On the other hand, when the scattering portion 52 of the rotary polygon mirror 24 which rotates at the specified rotational speed is irradiated with laser light, it is reflected by the rotary polygon mirror 24 as shown in FIGS. 3 (A) and 3 (B). The laser light is scattered.

  When the laser beam is irradiated to the deflection surface 50, the laser beam is irradiated into the proper angle range, so the intensity of the laser beam outside the specified angle range becomes small. On the other hand, when the laser beam is irradiated to the scattering part, the laser beam is scattered, so the intensity of the laser beam outside the proper angle range becomes large.

The rotary polygon mirror 24 of the present embodiment is an example of a deflection unit described in the claims.
<Distance measurement processing>
Next, distance measurement processing performed by the control unit 42 will be described.

The distance measurement process in the present embodiment is started when the ignition switch of the vehicle is turned on and power is supplied to the laser radar device 10.
When the ranging process is started, as shown in FIG. 4, the control unit 42 first outputs an SC drive signal (S110). The SC drive circuit 26 having received this SC drive signal drives the scanner mechanism unit 25 and hence the rotary polygon mirror 24 so as to rotate at the specified rotational speed.

  Subsequently, in the distance measurement process, the control unit 42 determines whether or not it is the position detection light emission timing defined in advance (S120). The position detection light emission timing said here is a start timing of a period with high possibility that each of the scattering parts 52 of the rotating polygon mirror 24 passes an irradiation range. In S120, when the detection result of the sensor that detects the rotation angle of the rotary polygon mirror 24 matches the angle representing the position detection light emission timing, it may be determined that it is the position detection light emission timing. In S120, if it is determined that the position detection light emission timing is reached, the scattering portion transition time corresponding to the time length to the next position detection light emission timing elapses, the position detection light emission timing is determined. You may.

  As a result of the determination in S120, if it is not the position detection light emission timing (S120: NO), the control unit 42 stands by until the position detection light emission timing. On the other hand, as a result of the determination in S120, when the position detection light emission timing comes (S120: YES), the control unit 42 outputs the first light emission command as the light emission signal Es to the light emission unit 20. The light emitting unit 20 that has acquired the first light emission command emits laser light whose signal level changes in a pulsed manner at a predetermined light emission interval. Note that the emission of the laser light here is performed for a first specified time which is a time length defined in advance so that the laser light is emitted a plurality of times.

  Subsequently, in the distance measurement process, the control unit 42 determines whether the scattered light intensity detected by the scattered light receiving unit 60 is equal to or higher than a predetermined threshold value Th defined in advance (S140). The prescribed threshold value Th here is obtained in advance as an experiment or the like as the scattered light intensity when the scattering portion 52 of the rotary polygon mirror 24 is present at the predefined reference position of the irradiation range.

  As a result of the determination in S140, if the scattered light intensity is less than the specified threshold Th (S140: NO), the control unit 42 measures that the scattering unit 52 of the rotating polygon mirror 24 is not present at the reference position. Wait for distance processing to be performed. On the other hand, as a result of the determination in S140, if the scattered light intensity is equal to or higher than the prescribed threshold Th (S140: YES), the control unit 42 assumes that the scattering unit 52 of the rotating polygon mirror 24 is present at the reference position. And shift the distance measurement process to S150.

  In S150, the control unit 42 starts a timer that measures an elapsed time. Then, the control unit 42 determines whether the measurement result by the timer has reached a predetermined time defined in advance (S160). The specified time said here is the start of the part which reflects the laser beam to the appropriate angle range at the deflection surface 50 of the rotating polygon mirror 24 after the scattering part 52 of the rotating polygon mirror 24 passes the reference position in the irradiation range The position is the length of time it takes to reach its reference position.

If it is determined in S160 that the elapsed time is less than the specified time (S160: NO), the control unit 42 stands by until the elapsed time becomes the specified time.
On the other hand, when the elapsed time reaches the specified time (S160: YES), the control unit 42 initializes the measurement result of the timer and shifts the distance measurement process to S170. In S170, the control unit 42 outputs the second light emission command as the light emission signal Es to the light emission unit 20.

  The light emitting unit 20 that has acquired the second light emission command emits laser light whose signal level changes in a pulsed manner at a predetermined light emission interval. Note that the emission of laser light here is performed for a second specified time which is a predetermined time length. In the second prescribed time period, after the start position of the portion that reflects the laser light to the appropriate angle range in the deflection surface 50 of the rotary polygon mirror 24 passes through the reference position, the deflection surface 50 in the appropriate angle range It is the length of time required for the end position of the portion that reflects the laser light to pass the reference position.

  Subsequently, the control unit 42 generates target information based on the measurement data generated by the detection circuit 40 during the second prescribed time (S180). Since the process of generating this target information is well known, the detailed description is omitted here. In the present embodiment, for example, clustering processing may be used as a method of generating target information.

Thereafter, the control unit 42 shifts the distance measurement process to S120.
As described above, in the distance measurement process of this embodiment, when the position detection light emission timing comes, the laser light is emitted for the first prescribed time. When the scattered light intensity detected by the scattered light receiving unit 60 becomes equal to or more than the specified threshold Th due to the emission of the laser light, the scattering unit 52 of the rotating polygon mirror 24 starts the timer as having reached the reference position in the irradiation range. Do.

Then, after the scattering portion 52 of the rotary polygon mirror 24 reaches the reference position in the irradiation range, when a prescribed time elapses, laser light is irradiated to the appropriate angle range to generate target information.
In addition, the laser radar apparatus 10 which performed the ranging process of this embodiment functions as an optical scanning apparatus described in the claim.
[Effect of First Embodiment]
In such a laser radar device 10, when the laser beam from the laser diode 21 is irradiated to the deflection surface 50 of the rotating polygon mirror 24 rotating at the specified rotational speed, the laser beam is in the appropriate angle range. It is irradiated. On the other hand, when the laser beam from the laser diode 21 is irradiated to the scattering portion 52 of the rotating polygon mirror 24 rotating at the specified rotational speed, the laser beam is scattered.

  Then, when laser light is irradiated to the deflection surface 50 of the rotary polygon mirror 24, the laser light is irradiated within the proper angle range, so the intensity of the laser light outside the proper angle range decreases. On the other hand, when the scattering portion 52 of the rotary polygon mirror 24 is irradiated with the laser beam, the laser beam is scattered, so the intensity of the laser beam outside the proper angle range becomes large.

  In other words, the scattered light intensity detected by the scattered light receiving unit 60 is such that when the scattering unit 52 of the rotating polygon mirror 24 is irradiated with the laser light, the deflection surface 50 of the rotating polygon mirror 24 is irradiated with the laser light It will be larger than it would be.

  Therefore, according to the laser radar device 10, when the scattered light intensity detected by the scattered light receiving unit 60 becomes equal to or higher than the specified threshold Th, it can be detected that the scattering unit 52 is located at the reference position in the irradiation range.

  Moreover, in the laser radar device 10, the detection of the rotation angle of the rotary polygon mirror 24 is realized by irradiating the rotary polygon mirror 24 with laser light and receiving the scattered light of the laser light by the scattered light receiving unit 60. ing. Therefore, according to the laser radar device 10, the rotation angle of the rotary polygon mirror 24 can be detected without making the device configuration complicated.

  As described above, according to the laser radar device 10, in the optical scanning device mounted on a vehicle, the device configuration can be simplified while improving the detection accuracy of the position of the optical system.

  Further, in the laser radar device 10 of the present embodiment, the scattered light receiving unit 60 is out of the light path from the rotary polygon mirror 24 to the appropriate angle range, and at least one of the laser light scattered by the scattering unit 52 of the rotary polygon mirror 24. It is placed at the position where the department reaches.

  Therefore, according to the scattered light receiving unit 60 of the laser radar device 10, the laser light scattered by the scattering unit 52 can be detected more reliably without preventing the irradiation of the laser light to the appropriate angle range.

  In the distance measurement process of the present embodiment, the first prescribed time period after the light receiving intensity at the scattered light receiving unit 60 becomes equal to or greater than the prescribed threshold value Th, as a start condition of irradiating the laser beam to the appropriate angle range. It is assumed that it has passed.

For this reason, according to the distance measurement process, it is possible to define the timing for causing the light emitting unit 20 to emit the laser light by the elapsed time after the light receiving intensity at the scattered light receiving unit 60 becomes the specified threshold Th or more. Can be simplified.
Second Embodiment
The laser radar device of the second embodiment differs from the laser radar device 10 of the first embodiment mainly in the contents of the distance measurement processing. Therefore, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted, and the distance measurement processing different from the first embodiment will be mainly described.
<Distance measurement processing>
The distance measurement process of the present embodiment is started when the ignition switch of the automobile is turned on and the power to the laser radar device 10 is supplied.

  When the ranging process is started, as shown in FIG. 5, the control unit 42 first outputs an SC drive signal (S210). The SC drive circuit 26 having received this SC drive signal drives the scanner mechanism unit 25 and hence the rotary polygon mirror 24 so as to rotate at the specified rotational speed.

  Subsequently, in the distance measurement process, the control unit 42 outputs a light emission command as the light emission signal Es to the light emitting unit 20 (S220). The light emitting unit 20 that has acquired the light emission command emits laser light whose signal level changes in a pulse shape at a predetermined light emission interval. The emission of the laser light of the present embodiment is repeated until the distance measurement process is completed.

  Subsequently, in the distance measurement process, the control unit 42 determines whether the scattered light intensity detected by the scattered light receiving unit 60 is equal to or higher than a predetermined threshold Th (S230). As a result of the determination in S230, if the scattered light intensity is equal to or higher than the prescribed threshold Th (S230: YES), the control unit 42 determines that the scattering unit 52 of the rotating polygon mirror 24 is passing through the irradiation range. The distance processing is returned to S210.

  On the other hand, as a result of the determination in S230, if the scattered light intensity is less than the prescribed threshold Th (S230: NO), the control unit 42 assumes that the deflection surface 50 of the rotating polygon mirror 24 is passing through the irradiation range. The distance measurement process is shifted to S240. In S240, the control unit 42 stores the measurement data generated by the detection circuit 40 in the RAM 46 in association with the current time Tx.

  Subsequently, it is determined whether the number of measurement data stored in the RAM 46 is equal to or more than a predetermined number defined in advance (S250). The prescribed number referred to herein is the number of measurement data that can be generated in the time length required for the deflection surface 50 of the rotary polygon mirror 24 to pass through the irradiation range, that is, the number of times of laser light emission in the time length.

  As a result of the determination in S250, if the number of measurement data is less than the specified number (S250: NO), the control unit 42 returns the distance measurement process to S230. On the other hand, when the number of measurement data reaches the specified number as a result of the determination in S250 (S250: YES), the control unit 42 shifts the distance measurement process to S260.

  In S260, the control unit 42 generates target information based on the measurement data stored in the RAM 46 (S260). In S260 in the present embodiment, from the measurement data stored in the RAM 46, measurement data (hereinafter referred to as "use measurement data") based on the laser beam irradiated to the appropriate angle range is extracted and target information Generate In this case, each measurement data within the appropriate angle range may be extracted as use measurement data. The determination as to whether the measurement data is within the appropriate angle range may be performed based on the time Tx associated with the measurement data. Specifically, based on the rotation speed of the rotary polygon mirror 24 and the length of time that the scattered light intensity detected by the scattered light receiving unit 60 is less than the specified threshold Th, the rotary polygon mirror from the reference position at time Tx The rotation angle of 24 may be calculated and it may be determined whether the rotation angle is within the appropriate angle range.

Thereafter, the control unit 42 deletes the measurement data stored in the RAM 46, and returns the distance measurement process to S230.
As described above, in the distance measurement process of the present embodiment, laser light is repeatedly emitted to generate measurement data. Then, according to the result of determining whether the scattered light intensity detected by the scattered light receiving unit 60 is equal to or more than the prescribed threshold value Th, the laser light emitted to the appropriate angle range out of the generated measurement data. Based measurement data is extracted to generate target information.
[Effect of Second Embodiment]
According to the distance measurement process of the present embodiment, it is possible to generate target information by extracting measurement data based on laser light irradiated to an appropriate angle range from measurement data.

For this reason, according to the distance measurement process of the present embodiment, the control of the light emission timing of the laser light can be simplified.
Other Embodiments
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It is possible in the range which does not deviate from the summary of this invention to implement in various aspects.

  For example, in the light emitting unit 20 in the above embodiment, the irradiation of the laser beam to the appropriate angle range is realized by rotating the rotary polygon mirror 24 at the specified rotational speed, but in the present invention, the irradiation to the appropriate angle range is performed. The method of realizing the irradiation of the laser beam is not limited to this.

  That is, as shown in FIG. 6, the light emitting unit 70 may include a laser diode 71 for emitting a laser beam, a lens 72 for deflecting the laser beam, and a motion mechanism 74 for linearly moving the lens 72. The lens 72 in this case is configured to deflect the laser light to an appropriate angle range when the laser light is irradiated to a specific site. In addition, the lens 72 is configured to scatter the laser light when the laser light is irradiated to a portion (that is, a scattering portion) different from the specific portion.

  In addition, the aspect which abbreviate | omitted a part of structure of the said embodiment as long as a subject is solvable is also embodiment of this invention. Moreover, the aspect comprised combining the said embodiment and modification suitably is also an embodiment of this invention. In addition, any aspect that can be considered without departing from the essence of the invention specified by the terms set forth in the claims is also an embodiment of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Laser radar apparatus 20, 70 ... Light emission part 21, 71 ... Laser diode 22 ... Drive circuit 23 ... Optical element 24 ... Rotation polygon mirror 25 ... Scanner mechanism part 26 ... Drive circuit 30 ... Light reception part 31 ... Light reception lens 32 ... Light reception Element 33 ... amplifier 40 ... detection circuit 42 ... control unit 44 ... ROM 46 ... RAM 48 ... CPU 50 ... deflection surface 52 ... scattering unit 60 ... scattered light receiving unit 72 ... lens 74 ... motion mechanism

Claims (5)

An optical scanning device (10) mounted on an automobile,
Light emitting means (21, 71) for emitting laser light;
It is a deflection means (24, 25, 72, 74) driven in a prescribed drive mode which is a prescribed drive mode, and the laser light from the light emitting means is at a prescribed site which is a prescribed site of the deflection means. When it is irradiated, the laser beam is irradiated to an appropriate angle range, and when the laser beam from the light emitting means is irradiated to the scattering portion which is the site of the deflecting means different from the defined site, the laser beam is scattered Deflection means which is a lens to
First light receiving means (60) for receiving the laser beam scattered by the deflection means;
Position detection means (42, S140, S230) for detecting that the scattering portion is positioned at a reference position when the light reception intensity becomes equal to or greater than a predetermined threshold as a result of light reception by the first light reception means;
The deflection means is
An optical scanning device driven by using a linear motion as the defined drive mode. The first light receiving means is
The optical scanning device according to claim 1, wherein the optical scanning device is disposed at a position out of the light path from the defined region to the appropriate angle range and at least a part of the laser light scattered by the scattering portion reaches. apparatus. Light emission control means (42, S150 to S170) for controlling the light emission timing of the laser light in the light emission means according to the detection result by the position detection means
The optical scanning device according to claim 1, further comprising: The light emission control means is
The light emitting means is caused to emit laser light when a predetermined time defined in advance has elapsed since the position detecting means detected that the scattering portion is positioned at the reference position. Optical scanning device described. An optical scanning device according to any one of claims 1 to 4.
A second light receiving means (30) for receiving the reflected light of the laser light from the appropriate angle range;
An object detection means (42, S180, S260) for detecting an object reflecting the laser beam based on the result of emitting laser light by the light emitting means and receiving the reflected light by the second light receiving means; Laser radar device equipped.