KR20160112876A - LIDAR Apparatus - Google Patents

Abstract

The present invention relates to a lidar device capable of calculating a distance to a reflector by emitting a laser beam in a scanning mode in each direction within a view angle and then separately obtaining reflecting light in each direction. The lidar device includes a light source, a rotating mirror, a receiving mirror, a light detecting part, and a calculating part. The light source generates source light. The rotating mirror is installed on an optical path of the source light to be able to rotate in a twin-axial direction to temporally change a reflecting surface direction thereof, and the rotating mirror temporally changes a direction of the source light to reflect the light to the front side as scan light. The receiving mirror is installed in front of the rotating mirror, reflects reception light, returned as the scan light is reflected by an external reflector, and includes a light penetration part formed in a position facing the rotating mirror not to block optical paths of the scan light, emitted from the rotating mirror, and the source light emitted to the rotating mirror. The light detecting part detects the reception light reflected by the receiving mirror. The calculating part calculates a distance to the external reflector based on flight hours from the generation of the source light to the detection of the reception light. The present invention is capable of enabling high speed and efficient scanning as well as having a compact size, significantly reducing consumed laser output, as compared to an existing device emitting laser in every direction within a view angle at the same time, and reducing costs for manufacture and management.

Description

LIDAR Apparatus < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus, and more particularly, to an apparatus for measuring a distance to an object to be measured and an object to be measured using optical means.

Light Detection And Ranging (LIDAR) is the detection of objects using light and the measurement of the distance to the object. Lada is similar in function to RADAR (Radio Detection And Ranging), but differs in that it uses light, unlike radars that use radio waves, and is sometimes referred to as an 'image radar' in this regard. Due to the difference in Doppler effect between light and microwave, Lada has a feature that it has better azimuth resolution and distance resolution than radar.

The Lidar device is mainly composed of an airplane that emits laser pulses from satellites or aircraft and receives backscattered pulses from atmospheric particles at the ground station. It has been used to measure the presence and movement of smoke, aerosols, cloud particles, etc., and to analyze the distribution of airborne dust particles or air pollution. However, in recent years, both transmission systems and receiving systems have been installed on the ground to perform obstacle detection, terrain modeling, and ground acquisition, , Civilian mobile robots, intelligent automobiles, and unmanned automobiles.

The ground Lidar apparatus typically comprises a transmission optical system for emitting laser pulses, a receiving optical system for receiving reflected light reflected by an external object, and an analyzer for determining the position of the object. Here, the analyzing unit calculates the distance to the reflected object by determining the time required for transmitting and receiving the reflected light, and calculates the distance to the reflected object received from each direction, thereby calculating the distance corresponding to the field of view corresponding to the field of view (FOV) You can also create a distance map in

However, since the conventional terrestrial Lidar apparatus emits laser having a wide beam width corresponding to the angle of view and acquires reflected light simultaneously from all directions in the angle of view to obtain the distance to the reflector, a very high output laser module is required Therefore, there is a problem that the price is very expensive. In addition, a laser module having a high output has a large size, and it is a factor for raising the overall size of the laser device.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a laser scanning apparatus capable of scanning a laser beam in various directions within a view angle and scanning the laser beam at high speed and efficiently by obtaining reflected light separately from each direction, It is a further object of the present invention to provide a Lada device which has a very low laser output, a compact size, a low manufacturing cost and a low operating cost.

According to an aspect of the present invention, there is provided a ladder apparatus including: a robot that is installed in a fixed place such as a military base or a moving object such as a robot or a vehicle, detects a nearby object, A rotating mirror, a receiving mirror, a light detecting portion, and a calculating portion. The light source generates the source light. The rotating mirror is installed on the optical path of the source light so as to be rotatable in the biaxial direction so that the direction of the reflecting surface is temporally variable and reflects the source light forward as scanning light with a different direction in time. The receiving mirror is installed in front of the rotating mirror. The scanning mirror reflects the received light reflected by the external reflector and returns to the mirror. The optical path of the source light incident on the rotating mirror and the scanning light emitted from the rotating mirror is blocked A light transmitting portion is formed at a position facing the rotating mirror. The light detecting unit detects the received light reflected by the receiving mirror. The calculation unit calculates the distance to the external reflector based on the flight time from when the source light is generated to when the received light is detected.

In a preferred embodiment, the Lidar apparatus further includes a wide-angle lens installed on the path of the scan light to expand the angle at which the scan light is emitted.

In one embodiment, the Lidar apparatus further includes a condenser lens for condensing the received light reflected by the reception mirror, so that the optical detection unit detects the received light focused by the condenser lens. In addition, the lidar apparatus may further include a light source mirror that reflects the source light emitted from the light source in the direction of the rotating mirror.

In another embodiment, the lidar apparatus further includes a concave mirror for focusing the received light reflected by the receiving mirror, and the photodetecting unit detects the received light focused by the concave mirror. Preferably, the Lada apparatus according to this embodiment further comprises a detector mirror for reflecting the received light focused by the concave mirror toward the optical detector. Further, a light source mirror that reflects the source light emitted from the light source in the direction of the rotating mirror may be additionally provided. In this case, it is preferable that the detector mirror and the light source mirror have integral reflection surfaces having different directions.

In another embodiment, the lidar device has a sloped surface, a first side disposed to face the front, and a second side perpendicular to the first side, wherein the sloped surface is parallel to the first side And a prism having a light incident portion having a source incident surface. In this case, the rotating mirror is disposed outside the source incidence surface, and the inner surface of the inclined surface acts as a receiving mirror. In a preferred embodiment, the light input portion of the prism is a protrusion protruding outward from the inclined surface or a recess recessed from the inclined surface to the inside of the prism.

According to the present invention, since a laser beam of a narrow beam width emitted from a laser module is scanned and emitted at high speed in all directions within an angle of view by a micromirror rotating at high speed, There is an effect that the laser output required for the apparatus is significantly reduced.

Thus, the manufacturing cost of the Lada device can be greatly reduced, and the size of the laser module and the overall size of the device are greatly reduced, resulting in a compact device. In addition, there is an advantage in that the power consumption during the operation of the apparatus is reduced in accordance with the reduced laser output. Furthermore, since the optical transmitting and receiving optical system and the receiving optical system are integrated, the size of the apparatus becomes remarkably small.

Further, as the width of the laser beam is reduced, it is possible to greatly increase the output of the laser beam emitted in each scanning direction, thereby making it possible to greatly increase the distance resolution and to make accurate distance map creation and distance and shape measurement .

Such a Lada apparatus of the present invention can be applied to a civilian mobile robot such as a surveillance reconnaissance robot, a FA transporting robot, an unmanned ship, a civilian unmanned helicopter, and the like, and can be utilized in an intelligent vehicle or a future unmanned vehicle. Further, the apparatus of the present invention can be applied to a weapon system such as a guarding robot, a battle robot, a defense robot, an unmanned helicopter, an unmanned helicopter, or an unmanned reconnaissance aircraft, thereby enhancing the accuracy of the equipment and greatly enhancing the military power.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding members are denoted by the same reference numerals. In the figure,
1 is a view showing a configuration of a transmission and reception optical system according to a first embodiment of a ladder apparatus according to the present invention;
FIG. 2 is a view showing an optical path of transmitted light in the Raid device of FIG. 1; FIG.
3 is a view showing the optical path of the incoming light in the Lada device of FIG. 1;
Figure 4 is a block diagram showing the electrical configuration of the ladder device of Figure 1;
5 is a view showing a configuration of a transmission / reception optical system according to a second embodiment of the laddering device according to the present invention;
FIG. 6 is a view showing an optical path of transmitted light in the Raid device of FIG. 5; FIG.
FIG. 7 is a view showing an optical path of a received light in the Lada apparatus of FIG. 5; FIG.
8 is a view showing a configuration of a transmission / reception optical system according to a third embodiment of the radar apparatus according to the present invention;
9 is a view showing an optical path of transmitted light in the Lada apparatus of FIG. 8;
10 is a view showing the optical path of the received light in the Lada apparatus of FIG. 8;
FIG. 11 is a view showing a modified embodiment of the triangular prism shown in FIG. 8; FIG.
12 is a view showing the shape of a prism according to another embodiment of the present invention; And
13 is a view showing the shape of a prism according to another embodiment of the present invention.

1, a ladder device according to a first embodiment of the present invention includes a light source 100, a light source mirror 120 disposed on the upper side of the light source 100, And a condenser lens 170 and a photodetector 180 positioned on the opposite side of the receiving mirror 130 with respect to the light source mirror 120. The condenser lens 170 and the photodetector 180 are disposed on the receiving mirror 130 and the micromirror 140,

The light source 100 generates and emits source laser light (hereinafter referred to as 'source light') for scanning a distance measurement object. The source light is preferably a pulsed laser. The light source mirror 120 has a rectangular or circular shape and reflects the source light emitted from the light source 100 toward the micromirror 140.

The micromirror 140 causes the source light reflected by the light source mirror 120 to be reflected again so that the retroreflected laser light (hereinafter, referred to as 'scan light') advances forward (upward in the drawing) . The micromirror 140 is rotatable in the left-right direction and the up-down direction with respect to the front face thereof, and is periodically moved in the up-and-down direction and repeatedly returned to the upper direction. In addition, And a large number of rotations are made in the left and right direction while being changed. Accordingly, the light reflected from the micromirror 140 is scanned in a predetermined pattern in each direction within the angle of view, and the scanning light emitted from the Lada apparatus can be scanned forward in a range of the angle of view periodically.

As the micromirror 140, a MEMS mirror provided with a mirror on the MEMS semiconductor is preferably used, but the present invention is not limited thereto. The MEMS mirror is described in detail in, for example, JP-A-10-0682955, and a person skilled in the art can easily implement the present invention, so that detailed description thereof will be omitted.

The receiving mirror 130 reflects the scanned light, which is emitted from the device and then reflected or scattered by an external reflector (hereinafter abbreviated as 'reflection') and then returned to the optical detector 180. The receiving mirror 130 has a rectangular or circular shape, and a through hole 132 is formed at a substantially central position. The micromirror 140 is disposed behind the through hole 132 of the receiving mirror 130 so that the source light incident on the micromirror 140 and the scan light emitted from the micromirror 140 pass through the through hole 122 So that it can pass through. That is, the receiving mirror 130 reflects the received light in the direction of the optical detector 180 so that the optical path of the source light and the scanning light is not blocked.

In the preferred embodiment, a wide-angle lens 150 and a filter 152 may be additionally provided in front of the receiving mirror 130 and the micromirror 140, that is, on the path of the scan light. The wide angle lens 150 expands the angle at which scan light is emitted, thereby widening the angle of view. The filter 152 passes only the light of the wavelength band generated by the light source 100 to prevent the light of the other band from mixing into the noise and prevents the foreign material such as water and dust from being introduced, And prevents the scan light and the received light from being reflected by the wide-angle lens 150. The filter 152 may be implemented as a coating for the wide angle lens 150.

The condensing lens 170 focuses the received light refracted by the wide-angle lens 150 and reflected by the receiving mirror 130. The photodetector 180 detects the converged incoming light. As the photodetector 180, for example, one or more avalanche photodiode (APD) arrays may be used.

In the radar apparatus according to the present embodiment, the transmission light and the reception light proceed as follows.

As shown in FIG. 2, the source light emitted from the light source 100 is reflected by the light source mirror 120 and is incident on the micromirror 140. The source light is refracted by the wide-angle lens 150 after being reflected again by the rotating micromirror 140. The scanning light refracted by the wide-angle lens 150 travels forward to an external reflector, that is, to a device where a detection target object may exist.

3, the received light after being reflected by the external reflector is refracted by the wide-angle lens 150, and then incident on the receiving mirror 130. As shown in FIG. The receiving light reflected by the receiving mirror 130 is converged by the condensing lens 170 and then converted into an electrical signal by the optical detecting unit 180.

4 shows the electrical configuration of the ladder device shown in Fig. The Lidar apparatus electrically includes a system control unit 200, a light emitting unit 202, a mirror driving unit 204, the optical detecting unit 180, and an absolute distance measuring unit 206.

The system control unit 200 controls the overall operation of the Lydia device.

The light emitting unit 202 includes the light source 100 shown in FIG. 1, generates a laser under the control of the controller 200, and outputs the generated source laser light through the optical system shown in FIG.

The mirror driving unit 204 generates and outputs a mirror driving signal for driving the horizontal and vertical rotations of the micromirror 140 under the control of the system control unit 200. In the preferred embodiment, information on the horizontal and vertical rotations of the micromirror 140 according to the mirror driving signal is stored in a look-up table (not shown), and the mirror driver 204, The mirror driving signal is generated based on the information stored in the lookup table with reference to the scan range information set in advance in the controller 200. [ The scan range information may vary depending on the user's setting.

The photodetector 180 detects the converged light by the condenser lens 170 as described above. The absolute distance measuring unit 206 measures the time of flight (TOF) of the optical signal, that is, the time when the light is emitted from the light emitting unit 202, The distance to the reflector is calculated. As described above, in the preferred embodiment, the photodetector 180 is implemented using an APD array having a plurality of avalanche photodiodes (APDs). In this embodiment, the absolute distance measurement unit 206 calculates the distance to the reflector in each APD unit. In particular, in the preferred embodiment, the absolute distance measurement unit 206 constructs a distance map image that displays the calculated distances for each APD by one pixel. The absolute distance measurement unit 206 provides distance data and / or a distance map image to the system control unit 200.

The above-mentioned Lida system operates as follows.

When the source light is generated and emitted from the light source 100 under the control of the system control unit 200, the source light is reflected by the light source mirror 120 and is incident on the micromirror 140.

The micromirror 140 is periodically rotated in the left and right direction and the up and down direction in accordance with the driving of the mirror driving unit 204. Accordingly, the reflected light incident on the micromirror 140 is continuously changed by the micromirror 140 And the reflected scan light is refracted by the wide-angle lens 150 and emitted toward the front of the apparatus.

The emitted scan light is reflected or scattered by an external reflector and then returned. The returning light to be returned is refracted by the wide-angle lens 150 and then incident on the receiving mirror 130. [ The received light reflected by the receiving mirror 130 is focused by the condenser lens 170 and is imaged on the APD of the optical detector 180. Each APD of the photodetector 180 is converted into an electrical signal by the imaging light.

The absolute distance measuring unit 206 calculates the distance to the reflector in each APD unit, and constructs a distance map image. Here, the distance map image refers to an image formed by varying the brightness and / or color of a pixel corresponding to a corresponding reflection point in an image according to the distance to each reflector reflection point.

According to the optical system shown in FIG. 1, since the received light can not be reflected at the portion where the through hole 132 is formed on the receiving mirror 130, there is no information about the corresponding portion in the transaction map image . However, such a non-detection area can be sufficiently reduced by minimizing the size of the through-hole 132 within a range that does not block the optical path. In one embodiment, the diameter of the mirror surface of the micromirror 140 is approximately 1 millimeter (mm), and the diameter of the through hole 132 is several millimeters.

5 shows a second embodiment of the laddering device according to the present invention.

The ladder device according to the present embodiment includes a light source 100, a light source mirror 120 disposed on the upper portion of the light source 100 in the drawing, a reception mirror 130 disposed in a lateral direction of the light source mirror 120, A concave reflecting mirror 360 located on the opposite side of the receiving mirror 130 with respect to the light source mirror 120 and a detector mirror 160 disposed on the front side of the concave reflecting mirror 360 362, and a light detector 180 provided above the detector mirror 362. A separate condenser lens 170 may be additionally provided on the front surface of the optical detector 180. Also, in this embodiment, a wide-angle lens 150 and a filter 152 may be further provided on the forward path of the reception mirror 130 and the micromirror 140, that is, on the path of the scan light, as in the first embodiment.

The configuration and function of the light source 100, the light source mirror 120, the receiving mirror 130, the micromirror 140, the wide angle lens 150, the filter 152, the condenser lens 170, Is the same as that of the first embodiment shown in FIG. 1, so that a detailed description thereof will be omitted. The electrical configuration shown in Fig. 2 can also be applied to this embodiment as well.

5, the concave reflecting mirror 360 focuses the incoming light refracted by the wide-angle lens 150 and reflected by the receiving mirror 130. As shown in FIG. The detector mirror 362 reflects the received light focused by the concave reflecting mirror 360 toward the optical detector 180. In a preferred embodiment, the detector mirrors 362 are integrally formed with the light source mirrors 120 and are fabricated by separately fabricating and attaching the back side to each other so as to face opposite directions, or by mirror coating both sides of one member. The condenser lens 170 focuses the re-reflected light reflected by the detector mirror 362 so that the received light can be incident into the narrow sensor surface of the optical detector 180.

In the radar apparatus according to the present embodiment, the transmission light and the reception light proceed as follows.

As shown in FIG. 6, the source light emitted from the light source 100 is reflected by the light source mirror 120 and is incident on the micromirror 140. The source light is refracted by the wide-angle lens 150 after being reflected again by the rotating micromirror 140. The scanning light refracted by the wide-angle lens 150 travels forward to an external reflector, that is, to a device where a detection target object may exist.

7, the received light after being reflected by the external reflector is refracted by the wide-angle lens 150, and then incident on the receiving mirror 130. As shown in FIG. The incoming light reflected by the receiving mirror 130 is focused by the concave reflecting mirror 360. The reflected light focused by the concave reflecting mirror 360 is reflected again by the detector mirror 362 and directed toward the light detecting unit 180. The light is refracted and focused by the condensing lens 264, ).

5 is the same as that of the apparatus shown in FIG. 1, and thus a detailed description thereof will be omitted.

8 shows a third embodiment of the laddering device according to the present invention.

The ladder device according to the present embodiment includes a light source 100 and a triangular prism 400 disposed on the upper portion of the light source 100 in the drawing. In one embodiment, the triangular prism 400 is a triangular prism having a sloped surface 402, a first side 404 and a second side 406 and having a triangular cross section. In particular, it is preferable that the prism 400 is a right angle prism in which the first side surface 404 and the second side surface 406 are orthogonal to each other to facilitate processing and assembly of each optical component.

8 includes a light source mirror 420 and a micromirror 140 disposed outside the inclined surface 402 of the triangular prism 400 and a second side surface 406 of the triangular prism 400, And a condensing lens 170 and a photodetector 180 disposed outside the photodetector. Also in this embodiment, the wide angle lens 150 and the filter 152 may be additionally provided on the outer side of the first side surface 404 of the triangular prism 400.

The configuration and function of the light source 100, the light source mirror 120, the micromirror 140, the wide angle lens 150, the filter 152, the condenser lens 170, The detailed description thereof will be omitted. The electrical configuration shown in Fig. 2 can also be applied to this embodiment as well.

The inclined surface 402 of the prism 400 functions as a receiving mirror 130 that reflects the incoming light reflected by the external reflector after being emitted from the radar apparatus in the direction of the optical detector 180. Generally, the inclined surface 402 of the prism 400 has a sufficient reflection characteristic in itself. However, in order to minimize the loss of light, the reflective surface 402 is provided with a reflection surface such that the reflective surface faces the inside of the prism 400 .

A protrusion 410 protruding outward is formed on the inclined surface 402 of the prism 400. The protrusion 410 has a source incidence surface 412 parallel to the first side 404 and a second inclined surface 402 parallel to the second side 406 and connecting the inclined surface 402 from the end of the source incidence surface 412 And a vertical surface 414 which is formed by

The light source mirror 120 is attached near the inner edge of the protrusion 410 at the inclined surface 402 of the prism 400. [ The light source mirror 120 may be formed by applying a reflective coating to the inclined surface 402 of the prism 400 to realize the receiving mirror 130 and then applying a reflective coating to the back surface of the reflective coating so that the reflective surface faces the outside, As shown in FIG. The light source mirror 120 reflects the source light emitted from the light source 100 toward the micromirror 140. In the present embodiment, the light source 100 is disposed such that the source light is directed to the center of the light source mirror 120 below the light source mirror 120.

The micromirror 140 is installed below the source incidence surface 412 of the protrusion 410 and is in contact with the source incidence surface 412 of the inclined surface 402 of the prism 400 and the light source mirror 120 As shown in Fig. The micromirror 140 reflects the incident light after being reflected by the light source mirror 120 so that the retroreflected scan light passes through the source incidence surface 412 and the first side surface 404 of the prism 400 (Upward in the figure) of the apparatus.

In the radar apparatus according to the present embodiment, the transmission light and the reception light proceed as follows.

As shown in FIG. 9, the source light emitted from the light source 100 is reflected by the light source mirror 120 and is incident on the micromirror 140. The source light is reflected by the rotating micromirror 140 and then enters the prism 400 through the source incidence surface 412 of the protrusion 410 of the prism 400 and enters the first side 404 . The scan light emitted from the prism 400 is refracted by the wide-angle lens 150. The scanning light refracted by the wide-angle lens 150 travels forward to an external reflector, that is, to a device where a detection target object may exist.

10, the incoming light after being reflected by the external reflector is refracted by the wide-angle lens 150 and then reflected by the prism 400 through the first side 404 of the prism 400, . In the prism 400, the incident light is reflected by the inclined surface 402 and then emitted through the second side surface 406. The reflected light is focused by the condenser lens 170 and then reflected by the photodetector 180 as an electrical signal .

8 is the same as that of the apparatus shown in FIG. 1, so that a detailed description thereof will be omitted.

According to the optical system shown in FIG. 8, since the transmitted light can not be reflected at the portion where the protrusion 410 of the prism 400 is formed, information may not exist in the corresponding portion of the transaction map image . However, such a non-detection area can be sufficiently reduced by minimizing the size of the protrusion 410 of the prism 400 within a range that does not block the optical path.

In another modified embodiment of FIG. 8, instead of the protrusions 410, grooves recessed into the prism from the inclined surface 402 may be formed. FIG. 11 shows a prism 400a according to this embodiment. 11, the prism 400a has a groove 420 recessed inwardly on the inclined surface 402, and the groove 420 is formed in the inclined surface 402, And a vertical surface 424 parallel to the second side surface 406 and connecting the inclined surface 402 from the inner end of the source incidence surface 422. Since the operation of the ladder device employing such a prism is the same as that described above, a description thereof will be omitted.

On the other hand, in another embodiment, the prism 400 and the wide-angle lens 150 shown in Fig. 8 can be integrated. FIG. 12 shows an example of a prism 440 according to this embodiment. In the embodiment of FIG. 12, the first side 444 of the prism 440 is not planar but curved outwardly convexly, so that the first side 444 also serves as a convex lens. When such a prism 440 is adopted, it is not necessary to separately provide the wide-angle lens 150, so that the processing cost of the wide-angle lens 150 and the airflow for assembling and aligning the wide-angle lens 150 are greatly reduced . Since the operation of the ladder device employing such a prism is the same as that described above, a description thereof will be omitted.

In another embodiment, the prism 400 and the condenser lens 170 shown in FIG. 1 may be integrated. FIG. 13 shows an example of the prism 460 according to this embodiment. In the embodiment of FIG. 10, the second side 466 of the prism 460 is not planar but curved outwardly convexly, so that the second side 466 also serves as a convex lens. In the case of adopting such a prism 466, there is no need to separately provide the condenser lens 170, so that the processing cost of the condenser lens 170 and the airflow for assembling and aligning the condenser lens 170 can be greatly reduced . The operation of the ladder device employing such a prism is also the same as that described above, so that a description thereof will be omitted.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

For example, in the above description, the through hole 132 is formed in the receiving mirror 130 so that the light path of the source light incident through the light source mirror 120 and the scanning light reflected by the micromirror 140 are not blocked Instead of forming the through-hole 132, it is sufficient that only the mirror coating is removed from the receiving mirror 130 so that light can be transmitted therethrough.

Although the micromirror 140 is described as being mounted behind the through-hole 132 of the receiving mirror 130 in the above-described embodiment, in a modified embodiment, the micromirror 140 is installed in the through-hole 132 It may be installed in front of it. Particularly, when the micromirror 140 is disposed in front of the through-hole 132, a light transmitting portion such as the through-hole 132 is not necessarily required. In such an embodiment, And only the signal line can pass through the receiving mirror 130. [

In the above description, the filter 152 is described as being provided on the front or the front of the wide-angle lens 150. However, in another embodiment, the filter 152 may be disposed in front of the receiving mirror 130 or the condensing lens 170 Or a coating on the front side.

In addition, although a plurality of embodiments have been described above, it goes without saying that the features of the embodiments can be combined and implemented.

Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Light source
120: Light source mirror
130: Receiving mirror, 132: Through hole
140: Micro mirror
150: Wide angle lens
152: Filter
170: condenser lens
180:
360: concave reflecting mirror, 362: detector mirror
400, 400a, 440, 460: prism
402: sloped surface, 404, 444: first side, 406, 466: second side
410: protruding portion, 412: source incidence surface, 414: vertical surface
420: groove, 422: source incidence surface, 424: vertical surface

Claims (15)

A light source for generating a source light;
A rotating mirror installed on the optical path of the source light so as to be rotatable in a biaxial direction, the direction of the reflecting surface being temporally variable, and reflecting the source light forward as scan light with a different direction in time;
The scanning light is reflected by an external reflector and is reflected by the external reflector. The optical path of the scanning light emitted from the rotating mirror and the source light incident on the rotating mirror are blocked A receiving mirror on which a light transmitting portion is formed at a position facing the rotating mirror;
A photodetector for detecting the received light reflected by the receiving mirror; And
An arithmetic unit for calculating a distance to the external reflector based on a flight time from when the source light is generated to when the received light is detected;
Lt; / RTI > The method according to claim 1,
A condensing lens for focusing the received light reflected by the receiving mirror;
And the light detecting unit detects the received light converged by the condensing lens. The method according to claim 1,
A light source mirror for reflecting the source light emitted from the light source in the direction of the rotating mirror;
Further comprising: The method according to claim 1,
A wide-angle lens disposed on a path of the scan light to expand the angle at which the scan light is emitted;
Further comprising: The method according to claim 1,
A concave mirror for focusing the received light reflected by the receiving mirror;
And the photodetector detects the received light focused by the concave mirror. The method of claim 5,
A detector mirror for reflecting the received light converged by the concave mirror toward the optical detecting portion;
Further comprising: The method of claim 6,
A light source mirror for reflecting the source light emitted from the light source in the direction of the rotating mirror;
Respectively,
Wherein the detector mirror and the light source mirror are integral with each other with reflecting surfaces in different directions. The method of claim 5,
A wide-angle lens disposed on a path of the scan light to expand the angle at which the scan light is emitted;
Further comprising: The method according to claim 1,
A light incident portion having a slope, a first side disposed to face the front side, and a second side surface perpendicular to the first side surface, the light incident portion having a source incident surface parallel to the first side surface is formed on the inclined surface A prism;
And,
The rotating mirror is disposed outside the source incidence surface,
Wherein the inner surface of the inclined surface acts as the receiving mirror. The method of claim 9,
A light source mirror installed outside the inclined surface of the prism and reflecting the source light emitted from the light source in the direction of the rotating mirror;
Further comprising: The apparatus of claim 9, wherein the light input portion of the prism is a protrusion protruding outward from the inclined surface. The apparatus of claim 9, wherein the light input portion of the prism is a groove recessed from the inclined surface to the inside of the prism. The method of claim 9,
And the reflective surface is provided on the inclined surface of the prism such that the reflective surface faces the inside of the prism. The method of claim 9,
A wide-angle lens disposed on a path of the scan light to expand the angle at which the scan light is emitted;
Further comprising: The method of claim 9,
Wherein at least one of the first and second sides of the prism is curved outwardly convex.

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