Scan-type omnidirectional lidar device

Abstract

The scan-type omnidirectional LIDAR device according to the present invention comprises: a light-emitting unit for emitting light in a predetermined wavelength band; a scan mirror installed on the path of the light emitted from the light-emitting unit such that the direction of a reflective surface thereof is temporally varied, the scan mirror being configured to scan the light emitted from the light-emitting unit and to reflect same upwards; an upper mirror positioned above the scan mirror such that light reflected by the scan mirror is reflected to the outside of the omnidirectional LIDAR device; a light-collecting lens unit for reception, which collects light reflected and returned by a reflector positioned outside the omnidirectional LIDAR device; a receiving mirror for reflecting the light collected by the light-collecting lens unit for reception downwards; and a light detection unit positioned below the receiving mirror so as to detect the light reflected by the receiving mirror. According to the present invention, spreading of the returned light can be sufficiently alleviated by the light-collecting lens unit for reception, thereby improving the returned light detection efficiency of the light detection unit.

Description

Scan type omnidirectional lidar device

[0001] The present invention relates to a scan-type omnidirectional lidar device that scans light emitted from a light emitting unit and detects an external reflector using the scanned light.

[0002] LIDAR (light detection and ranging) is similar to radar (radio detection and ranging) in terms of function, but it differs from radar in that it uses light, unlike radar which uses radio waves. For this reason, LIDAR is also called 'imaging radar'.

[0003] Until now, airborne LiDAR devices, mounted on satellites or aircraft, have been the mainstream. They emit light and the light scattered by atmospheric particles is received at ground-based observatories. These airborne LiDAR devices have been used to measure the presence and movement of dust, smoke, aerosols, and cloud particles, along with wind information, and to analyze the distribution of dust particles in the atmosphere or the level of air pollution. However, research has recently been actively conducted on terrestrial LiDAR devices, in which both the transmitting and receiving optical systems are placed on the ground, performing various functions such as obstacle detection, terrain modeling, and acquiring the location of reflectors.

[0004] A lidar device typically consists of a transmitting optical system that emits light to the outside, a receiving optical system that receives the light reflected by an external reflector and returned, and an analysis unit that calculates the distance from the lidar device to the reflector. Here, the analysis unit calculates the distance from the lidar device to the reflector based on the time difference required for the receiving optical system to receive the light emitted from the transmitting optical system, and further calculates the distance in each direction using light received from various directions, thereby creating a distance map corresponding to the field of view (FOV).

[0005] Among conventional lidar devices, there are flash lidar devices and scan type lidar devices.

[0006] Flash lidar devices typically emit light with a wide beam width and calculate the distance from the lidar to the reflector by capturing the light reflected by an external reflector. Implementing a flash lidar device requires a very power-intensive light source, and the structures of the transmitting and receiving optical systems are relatively complex, as they transmit and receive light in multiple directions simultaneously.

[0007] In contrast, among the scan-type lidar devices, the 2D scan-type lidar device is composed of a single laser and a single receiving element, and typically acquires an image in a two-dimensional plane including the direction of propagation of light by using a method of rotating the receiving mirror. In addition, among the scan-type lidar devices, the 3D scan-type lidar device is composed of a plurality of lasers and a plurality of receiving elements, and acquires an image in a three-dimensional space including the direction of propagation of light by using a method of rotating the receiving mirror.

[0008] As such, since conventional scan-type lidar devices require the rotation of the receiving mirror to detect external reflectors, the lidar device must be equipped with a motor for rotating the receiving mirror. However, if the lidar device is equipped with a motor for rotating the receiving mirror, there is a problem in that the lidar device becomes larger and the power consumption required for the rotation of the receiving mirror also increases.

[0009] In addition, conventional scan-type lidar devices are configured so that light reflected by an external reflector and returned directly enters a receiving mirror, is reflected from a specific point on the receiving mirror, and then enters a light detector. However, in this case, the returning light is relatively severely diffused during the process of being reflected from a specific point on the receiving mirror, which causes a problem of reducing the light detection efficiency of the light detector.

[0010] [Prior Art Literature]

[0011] (Patent Document 1) JP 5266739 B2 (May 17, 2013)

[0012] The purpose of the present invention is to provide a scan type omnidirectional lidar device capable of improving the light detection efficiency of a light detection unit.

[0013] In addition, the present invention aims to provide a scan type omnidirectional lidar device capable of detecting a reflector located externally without rotating a receiving mirror.

[0014] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0015] In order to achieve the above object, the scan-type omnidirectional lidar device according to the present invention may include: a light emitting unit that emits light of a predetermined wavelength band; a scan mirror that is installed on the path of light emitted from the light emitting unit so that the direction of its reflective surface varies temporally and scans the light emitted from the light emitting unit and reflects it upward; an upper mirror positioned above the scan mirror that reflects the light reflected by the scan mirror to the outside of the omnidirectional lidar device; a receiving condenser lens unit that focuses light reflected by a reflector positioned outside the omnidirectional lidar device and returns; a receiving mirror that reflects downward the light focused by the receiving condenser lens unit; and a light detection unit positioned below the receiving mirror that detects the light reflected by the receiving mirror.

[0016] The omnidirectional lidar device of the scan type according to the present invention may further include an expansion lens unit positioned between the scan mirror and the upper mirror, and expanding the angle of view of light reflected by the scan mirror.

[0017] The above expansion lens unit may include a plurality of expansion lenses arranged in a vertical direction to each other.

[0018] The above-mentioned receiving condenser lens unit may include a plurality of receiving condenser lenses arranged in a circular manner based on the vertical central axis of the omnidirectional lidar device.

[0019] At this time, the receiving condenser lens unit may further include an outermost housing that holds a receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses; and an inner housing that holds a receiving condenser lens positioned at the inner end compared to the receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses, and the inner housing may be arranged at the inner end of the outermost housing, and the receiving condenser lens positioned at the outermost end and the receiving condenser lens positioned at the inner end may be arranged to have a common horizontal center axis.

[0020] The above-mentioned receiving condenser lens unit may further include a plurality of receiving sub-condenser lenses positioned above the plurality of receiving condenser lenses and arranged in a circular manner around the vertical central axis of the omnidirectional lidar device.

[0021] At this time, the receiving condenser lens unit may further include an outermost housing having a receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses and a receiving sub-condenser lens positioned at the outermost end among the plurality of receiving sub-condenser lenses; and an inner housing having a receiving condenser lens positioned inward compared to the receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses and a receiving sub-condenser lens positioned inward compared to the receiving sub-condenser lens positioned at the outermost end among the plurality of receiving sub-condenser lenses, and the inner housing may be arranged on the inner side of the outermost housing, and the receiving condenser lens positioned at the outermost end and the receiving condenser lens positioned at the inner end may be arranged to have a common lens center axis, and the receiving sub-condenser lens positioned at the outermost end and the receiving sub-condenser lens positioned at the inner end may be arranged to have another common lens center axis.

[0022] The omnidirectional lidar device of the scan type according to the present invention may further include a detection focusing lens unit positioned between the scan mirror and the light detection unit, and focusing light reflected by the receiving mirror.

[0023] The above-mentioned detection focusing lens unit may include a plurality of detection focusing lenses arranged in a vertical direction to each other.

[0024] Since the present invention is configured such that light reflected by an externally located reflector and returned is focused by a receiving condenser lens unit before entering a receiving mirror, the phenomenon of the returning light spreading can be sufficiently alleviated by the receiving condenser lens unit. According to the present invention, the detection efficiency of the returning light by the light detection unit can be improved, and thus the distance range of the reflector that the light detection unit can detect can be significantly expanded.

[0025] In addition, since in the present invention, a plurality of receiving condenser lenses are arranged in a circular manner based on the vertical central axis of the omnidirectional lidar device, it is possible to receive and focus the reflected light incident over a 360° range in the horizontal direction. According to the present invention, since there is no need to necessarily rotate the receiving mirror in order to receive the reflected light incident over a 360° range in the horizontal direction, a means for rotating the receiving mirror is not required. Accordingly, the volume of the omnidirectional lidar device can be reduced, and the power consumption required for the operation of the omnidirectional lidar device can also be reduced.

[0026] FIG. 1 is a schematic drawing of an omnidirectional lidar device of a scan type according to a first embodiment of the present invention.

[0027] Figure 2a is a drawing showing an outermost receiving condenser lens held in the outermost housing.

[0028] Figure 2b is a drawing showing an inner receiving condenser lens held in the inner housing.

[0029] FIG. 3 is a drawing showing an inner housing illustrated in FIG. 2b arranged inside the outermost housing illustrated in FIG. 2a.

[0030] FIG. 4 is a schematic diagram illustrating an omnidirectional lidar device of a scan type according to a second embodiment of the present invention.

[0031] Figure 5a is a drawing showing an outermost receiving condenser lens and an outermost receiving sub-condenser lens held in the outermost housing.

[0032] Figure 5b is a drawing showing an inner housing having an inner receiving condenser lens and an inner receiving sub-condenser lens.

[0033] Figure 6 is a drawing showing an inner housing illustrated in Figure 5b arranged inside the outermost housing illustrated in Figure 5a.

[0034] Hereinafter, a scan-type omnidirectional lidar device according to the present invention will be described in detail with reference to the attached drawings. The attached drawings are provided merely as examples so that the technical idea of ​​the present invention can be sufficiently conveyed to those skilled in the art, and the present invention is not limited to the drawings presented below and may be embodied in various forms. When a part in this specification is said to "include" a certain component, this does not mean that other components are excluded, but that other components may be further included, unless specifically stated otherwise. In addition, the dotted line depicted in the attached drawings represents a central axis (i.e., a vertical central axis or a horizontal central axis).

[0035] FIG. 1 is a schematic diagram of an omnidirectional lidar device (1000: 1000-1) of a scan type according to a first embodiment of the present invention. As illustrated in FIG. 1, the omnidirectional lidar device (1000-1) of a scan type according to the first embodiment of the present invention may include a light emitting unit (100), a scan mirror (200), an upper mirror (300), a receiving condenser lens unit (400), a receiving mirror (500), and a light detecting unit (600).

[0036] The light emitting unit (100) emits light of a predetermined wavelength band to detect a reflector (10) located outside the omnidirectional lidar device (1000-1). For example, the light emitting unit (100) may be formed of or include a PLD (Pulsed Laser Diode) that emits light of a predetermined wavelength band in the form of pulses.

[0037] Light of a predetermined wavelength band emitted from the light emitting unit (100) is incident on the scan mirror (200). Here, the scan mirror (200) may be a MEMS (Micro-Electro Mechanical Systems) mirror in which the mirror is arranged on a MEMS (Micro-Electro Mechanical Systems) semiconductor.

[0038] The scan mirror (200) is installed so that the direction of its reflective surface changes over time on the path of light emitted from the light emitting unit (100), and scans the light emitted from the light emitting unit (100) and reflects it upward to the omnidirectional lidar device (1000-1).

[0039] The scan mirror (200) is arranged to be rotatable in two directions on the path of light emitted from the light emitting unit (100), so that the direction of its reflective surface can be changed over time. Here, the two-axis direction may mean a vertical direction (i.e., the up-down direction shown in FIG. 1) and a horizontal direction perpendicular thereto. The scan mirror (200) can rotate multiple times in the horizontal direction while rotating once in the vertical direction under the control of a control unit (not shown), and as a result, light incident on the scan mirror (200) travels upward of the scan mirror (200) while changing direction over time.

[0040] The upper mirror (300) is positioned above the scan mirror (200) and reflects the light reflected by the scan mirror (200) to the outside of the omnidirectional lidar device (1000-1) (more specifically, at least one of the side and bottom of the omnidirectional lidar device (1000-1)).

[0041] As illustrated in Fig. 1, the upper mirror (300) may be designed in a cone shape. Here, the cone-shaped upper mirror (300) means a shape that is symmetrical on both sides with respect to its vertical central axis (indicated by '○' in Fig. 1) and whose outer diameter gradually decreases from the top to the bottom. When the upper mirror (300) is in a cone shape, the light incident thereon can be reflected in all directions without the need to rotate the upper mirror (300) by a rotational driving means such as a motor. Therefore, the upper mirror (300) may not be rotated by a rotational driving means such as a motor and may always remain fixed. Furthermore, the upper mirror (300) may be configured as a dichroic mirror to reflect light of a predetermined wavelength band and transmit light other than the predetermined wavelength band.

[0042] An expansion lens unit (700) may be positioned between the scan mirror (200) and the upper mirror (300). The expansion lens unit (700) expands the field of view (FOV) of light reflected upward by the scan mirror (200) and transmits the expanded field of view light to the upper mirror (300). When the omnidirectional lidar device (1000-1) is equipped with the expansion lens unit (700), the range for detecting a reflector (10) located outside the omnidirectional lidar device (1000-1) can be further expanded.

[0043] The expansion lens unit (700) may be composed of only one expansion lens. That is, the expansion lens unit (700) may be composed of only the first expansion lens (711) illustrated in FIG. 1, and the first expansion lens (711) expands the angle of view of light reflected by the scan mirror (200).

[0044] However, there may be a limit to expanding the angle of view of light with only one expansion lens. Accordingly, the expansion lens unit (700) may include a plurality of expansion lenses (711, 721) arranged in a vertical direction to each other. When the expansion lens unit (700) includes a plurality of expansion lenses (711, 721), the plurality of expansion lenses (711, 721) may be arranged to have a common vertical central axis (indicated by '○' in FIG. 1).

[0045] More specifically, referring to the example of Fig. 1, the second expansion lens (721) is positioned above the first expansion lens (711) and serves to further expand the angle of view of light expanded by the first expansion lens (711). The first expansion lens (711) and the second expansion lens (721) may be arranged in a vertical direction with respect to each other and may be arranged to have a common vertical central axis (indicated by '○' in Fig. 1). Although only two expansion lenses (711, 721) are illustrated in Fig. 1, the number of expansion lenses constituting the expansion lens unit (700) may be three or more. Each expansion lens (711, 721) may be formed as a convex lens or a concave lens.

[0046] Meanwhile, when the upper mirror (300) emits light reflected by the scan mirror (200) to the outside of the omnidirectional lidar device (1000-1), the reflector (10) located outside the omnidirectional lidar device (1000-1) can reflect the light, and at least some of the light reflected by the reflector (10) returns to the omnidirectional lidar device (1000-1).

[0047] The receiving condenser lens unit (400) focuses the 'light reflected by the reflector (10) located outside the omnidirectional lidar device (1000-1) and returning' (hereinafter referred to as 'returned light'). As described above, when the return light is directly incident on the receiving mirror (500) and reflected at a specific point of the receiving mirror (500), the light spreading phenomenon occurs relatively severely. In contrast, when the return light is focused by the receiving condenser lens unit (400) before it is incident on the receiving mirror (500), the spreading phenomenon of the return light can be sufficiently alleviated, thereby improving the return light detection efficiency of the light detection unit (600).

[0048] Furthermore, if the omnidirectional lidar device (1000-1) is not equipped with a receiving condenser lens unit (400), the returned light may not properly enter the light detection unit (600) after being reflected at a specific point of the receiving mirror (500). In contrast, if the omnidirectional lidar device (1000-1) is equipped with a receiving condenser lens unit (400), the receiving condenser lens unit (400) focuses the returned light incident from various directions, so that a relatively larger amount of the returned light enters the light detection unit (600), and as a result, the light detection unit (600) can detect the returned light with higher efficiency.

[0049] The receiving condenser lens unit (400) may include a plurality of receiving condenser lenses (411, 412) arranged in a circular manner around the vertical central axis (○) of the omnidirectional lidar device (1000-1).

[0050] The plurality of receiving condenser lenses (411, 412) can be divided into a 'receiving condenser lens located at the outermost position' (hereinafter referred to as 'outermost receiving condenser lens') (411) and a 'receiving condenser lens located inside the outermost receiving condenser lens (411)' (hereinafter referred to as 'inner receiving condenser lens') (412). Here, the fact that the inner receiving condenser lens (412) is located inside the outermost receiving condenser lens (411) means that the inner receiving condenser lens (412) is located closer to the vertical central axis (○) of the omnidirectional lidar device (1000-1) than the outermost receiving condenser lens (411).

[0051] Each outermost receiving condenser lens (411) can receive and focus the return light incident over a range of, for example, 40° in the horizontal direction. Accordingly, a total of nine outermost receiving condenser lenses (411) can be provided in the omnidirectional lidar device (1000-1) to receive and focus the return light incident over a range of 360° in the horizontal direction. The outermost receiving condenser lenses (411) can be arranged around the vertical central axis (○) of the omnidirectional lidar device (1000-1), but can be spaced apart from each other by the same angle. That is, when the total number of outermost receiving condenser lenses (411) is nine, the nine outermost receiving condenser lenses (411) can be spaced apart from each other by 40° in the horizontal direction.

[0052] Likewise, each inner receiving condenser lens (412) can receive and focus the return light incident over a range of 40° in the horizontal direction. Accordingly, a total of nine inner receiving condenser lenses (412) can be provided in the omnidirectional lidar device (1000-1) to receive and focus the return light incident over a range of 360° in the horizontal direction. The inner receiving condenser lenses (412) can be arranged around the vertical central axis (○) of the omnidirectional lidar device (1000-1), but can be spaced apart from each other by the same angle. That is, when the total number of inner receiving condenser lenses (412) is nine, a total of nine inner receiving sub-condenser lenses (412) can be spaced apart from each other by 40° in the horizontal direction.

[0053] The outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can be arranged to correspond to each other 1:1 and have a common horizontal center axis (○').

[0054] The receiving condenser lens unit (400) may include only the outermost receiving condenser lens (411), and the outermost receiving condenser lens (411) may alleviate the spreading phenomenon of the returning light by focusing the returning light. However, there may be a limit to alleviating the spreading phenomenon of the returning light with only the outermost receiving condenser lens (411). Therefore, it may be preferable for the receiving condenser lens unit (400) to include the outermost receiving condenser lens (411) and the inner receiving condenser lens (412).

[0055] In order to sufficiently alleviate the phenomenon of the return light spreading, the focus of the outermost receiving condenser lens (411) and the focus of the inner receiving condenser lens (412) need to be appropriately adjusted. In order to adjust the focus of the receiving condenser lenses (411, 412), the distance between the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) must be a preset distance, and the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) must be fixed at positions so as to have the preset distance. In order to facilitate such distance and position setting, the receiving condenser lens unit (400) may additionally include an outermost housing (430: 430-1) and an inner housing (440: 440-1) as illustrated in FIGS. 2A, 2B, and 3.

[0056] FIG. 2a is a drawing showing an outermost receiving condenser lens (411) held in an outermost housing (430-1), and FIG. 2b is a drawing showing an inner receiving condenser lens (412) held in an inner housing (440-1). In addition, FIG. 3 is a drawing showing an inner housing (440-1) shown in FIG. 2b being arranged inside the outermost housing (430-1) shown in FIG. 2a.

[0057] As illustrated in FIG. 2A, the outermost housing (430-1) may be hollow and cylindrical, and may hold an outermost receiving condenser lens (411) among a plurality of receiving condenser lenses (411, 412). More specifically, the outermost receiving condenser lens (411) may be held in a column portion of the cylindrical outermost housing (430-1).

[0058] When return light is incident from the outside of the outermost housing (430-1) onto the outermost receiving condenser lens (411), the outermost receiving condenser lens (411) focuses the return light and transmits it to the inner receiving condenser lens (412) located on the inside of the outermost housing (430-1).

[0059] Figure 2a illustrates a front view of the outermost housing (430-1). Five outermost receiving condenser lenses (411) can be provided at the front of the outermost housing (430-1) and four can be provided at the rear of the outermost housing (430-1).

[0060] As illustrated in FIG. 2b, the inner housing (440-1) may also be hollow and cylindrical. The height of the inner housing (440-1) may be the same as the height of the outermost housing (430-1), but the diameter of the inner housing (440-1) is smaller than the diameter of the outermost housing (430-1).

[0061] The inner housing (440-1) may have an inner receiving condenser lens (412) among a plurality of receiving condenser lenses (411, 412). More specifically, the inner receiving condenser lens (412) may be held in a column portion of the cylindrical inner housing (440-1).

[0062] When the return light passes through the outermost receiving condenser lens (411) and enters the inner receiving condenser lens (412), the inner receiving condenser lens (412) focuses the return light and transmits it to the receiving mirror (500) located inside the inner housing (440-1).

[0063] Figure 2b illustrates a front view of the inner housing (440-1). Five inner receiving condenser lenses (412) can be provided at the front of the inner housing (440-1) and four can be provided at the rear of the inner housing (440-1).

[0064] As illustrated in Fig. 3, the inner housing (440-1) is arranged inside the outermost housing (430-1). At this time, the outermost receiving condenser lens (411) held by the outermost housing (430-1) and the inner receiving condenser lens (412) held by the inner housing (440-1) can be arranged to have a common horizontal center axis (○').

[0065] For reference, a light emitting unit (100), a scanning mirror (200), a light detecting unit (600), and a detection focusing lens unit (800) may be positioned at the lower portions of the outermost housing (430-1) and the inner housing (440-1) illustrated in FIG. 3, and an upper mirror (300) may be positioned at the upper portions of the outermost housing (430-1) and the inner housing (440-1). In addition, a receiving mirror (500) and an expansion lens unit (700) may be positioned at the inner portion of the inner housing (440-1) illustrated in FIG. 3.

[0066] Due to the outermost housing (430-1) and the inner housing (440-1), the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can be fixed at a fixed position, and thus the distance between the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can be always maintained constant. That is, when the receiving condenser lens unit (400) includes the outermost housing (430-1) and the inner housing (440-1), the focus of the receiving condenser lenses (411, 412) can be adjusted with high accuracy, and accordingly, the phenomenon of the return light spreading can be greatly alleviated compared to the prior art, and the return light detection efficiency of the light detection unit (600) can be improved.

[0067] In addition, since the alignment between the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) is completed simply by placing the inner housing (440-1) inside the outermost housing (430-1), there is no need to individually place the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) at fixed positions. Accordingly, when the receiving condenser lens unit (400) includes the outermost housing (430-1) and the inner housing (440-1), the time for manufacturing the omnidirectional lidar device (1000-1) can be shortened, and the cost required for manufacturing can be reduced.

[0068] The receiving mirror (500) is positioned inside the receiving condenser lens unit (400) and reflects the light focused by the receiving condenser lens unit (400) downwards toward the omnidirectional lidar device (1000-1). Since the light reflected by the receiving mirror (500) is return light, the path of the light reflected by the scan mirror (200) and the path of the light reflected by the receiving mirror (500) must not overlap each other. Accordingly, it is preferable that the receiving mirror (500) reflect the light focused by the receiving condenser lens unit (400) downwards toward the scan mirror (200).

[0069] As described above, since the receiving condenser lens unit (400) can receive and focus the return light incident over a 360° range in the horizontal direction, there is no need to rotate the receiving mirror (500) by a rotational driving means such as a motor. That is, in the present invention, the receiving mirror (500) always exists in a fixed state.

[0070] The number of receiving mirrors (500) may be provided to be the same as the number of outermost receiving condenser lenses (411) (or the number of inner receiving condenser lenses (412)). That is, if the number of outermost receiving condenser lenses (411) (or the number of inner receiving condenser lenses (412)) is 9, the number of receiving mirrors (500) may also be 9. The outermost receiving condenser lenses (411), the inner receiving condenser lenses (412) and the receiving mirrors (500) may be arranged to correspond to each other in a 1:1:1 ratio.

[0071] The light detection unit (600) is located below the receiving mirror (500). Furthermore, the light detection unit (600) may be located below the scan mirror (200) to prevent the path of the light reflected by the scan mirror (200) and the path of the light reflected by the receiving mirror (500) from overlapping each other.

[0072] The light detection unit (600) detects light reflected downward by the receiving mirror (500). Additionally, the light detection unit (600) can calculate the distance from the omnidirectional lidar device (1000-1) to the reflector (10) based on the time of flight (TOF) from the time the light emission unit (100) emits light to the time the light detection unit (600) detects the light. When the light emitted from the light emission unit (100) is pulsed light, the light detection unit (600) can be implemented by including an APD array having a plurality of avalanche photodiodes (APDs). In this case, the light detection unit (600) can calculate the distance to the reflector (10) for each APD unit and implement a distance map image that displays the calculated distance for each APD as one pixel.

[0073] A detection focusing lens unit (800) may be positioned between the scan mirror (200) and the light detection unit (600). The detection focusing lens unit (800) focuses the light reflected downward by the receiving mirror (500) and transmits the focused light to the light detection unit (600). When the omnidirectional lidar device (1000-1) is equipped with the detection focusing lens unit (800), the phenomenon of the return light spreading can be further reduced, and accordingly, the return light detection efficiency of the light detection unit (600) can also be further improved.

[0074] The detection condenser lens unit (800) may be composed of only one detection condenser lens. That is, the detection condenser lens unit (800) may be composed of only the first detection condenser lens (811) illustrated in FIG. 1, and the first detection condenser lens (811) focuses light reflected downward by the receiving mirror (500).

[0075] However, there may be limitations in alleviating the dispersion phenomenon of the return light with only one detection condenser lens. Accordingly, the detection condenser lens unit (800) may include a plurality of detection condenser lenses (811, 821) arranged in a vertical direction to each other. When the detection condenser lens unit (800) includes a plurality of detection condenser lenses (811, 821), the plurality of detection condenser lenses (811, 821) may be arranged to have a common vertical central axis (indicated by '○' in FIG. 1).

[0076] More specifically, referring to the example of Fig. 1, the second detection condenser lens (821) is positioned below the first detection condenser lens (811) and serves to re-condense the light condensed by the first detection condenser lens (811). The first detection condenser lens (811) and the second detection condenser lens (821) may be arranged in a vertical direction with respect to each other and may be arranged to have a common vertical central axis (indicated by '○' in Fig. 1). Although only two detection condenser lenses (811, 821) are illustrated in Fig. 1, the number of detection condenser lenses constituting the detection condenser lens unit (800) may be three or more. Each detection condenser lens (811, 821) may be formed of a convex lens.

[0077] Meanwhile, Fig. 4 is a schematic diagram of a scan-type omnidirectional lidar device (1000: 1000-2) according to a second embodiment of the present invention. The scan-type omnidirectional lidar device (1000-2) according to the second embodiment of the present invention is different from the scan-type omnidirectional lidar device (1000-1) according to the first embodiment of the present invention only in that the receiving condenser lens unit (400) further includes a plurality of receiving sub-condenser lenses (421, 422) in addition to a plurality of receiving condenser lenses (411, 412). Therefore, only the parts with the difference will be described below.

[0078] As illustrated in Fig. 4, the receiving condenser lens unit (400) includes a plurality of receiving condenser lenses (411, 412) and a plurality of receiving sub-condenser lenses (421, 422). The plurality of receiving sub-condenser lenses (421, 422) are positioned above the plurality of receiving condenser lenses (411, 412) and can be arranged around the vertical central axis (○) of the omnidirectional lidar device (1000-2).

[0079] The plurality of receiving sub-condenser lenses (421, 422) can be divided into a 'receiving sub-condenser lens located at the outermost position' (hereinafter referred to as 'outermost receiving sub-condenser lens') (421) and a 'receiving sub-condenser lens located inside the outermost receiving sub-condenser lens (421)' (hereinafter referred to as 'inner receiving sub-condenser lens') (422). Here, the fact that the inner receiving sub-condenser lens (422) is located inside the outermost receiving sub-condenser lens (421) means that the inner receiving sub-condenser lens (422) is located closer to the vertical central axis (○) of the omnidirectional lidar device (1000-2) than the outermost receiving sub-condenser lens (421).

[0080] Each outermost receiving sub-condenser lens (421) can receive and focus the return light incident over a range of, for example, 40° in the horizontal direction. Accordingly, a total of nine outermost receiving sub-condenser lenses (421) can be provided in the omnidirectional lidar device (1000-2) to receive and focus the return light incident over a range of 360° in the horizontal direction. The outermost receiving sub-condenser lenses (421) can be arranged around the vertical central axis (○) of the omnidirectional lidar device (1000-2), but can be spaced apart from each other by the same angle. That is, when the total number of outermost receiving sub-condenser lenses (421) is nine, the nine outermost receiving sub-condenser lenses (421) can be spaced apart from each other by 40°.

[0081] Likewise, each inner receiving sub-condenser lens (422) can receive and focus the return light incident over a range of 40° in the horizontal direction. Accordingly, a total of nine inner receiving sub-condenser lenses (422) can be provided in the omnidirectional lidar device (1000-2) to receive and focus the return light incident over a range of 360° in the horizontal direction. The inner receiving sub-condenser lenses (422) can be arranged around the vertical central axis (○) of the omnidirectional lidar device (1000-2), but can be spaced apart from each other by the same angle. That is, when the total number of inner receiving sub-condenser lenses (422) is nine, the nine inner receiving sub-condenser lenses (422) can be spaced apart from each other by 40°.

[0082] The outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) can be arranged to correspond to each other 1:1 and have a common horizontal center axis (○").

[0083] The outermost receiving sub-condenser lens (421) is positioned above the outermost receiving condenser lens (411), and the inner receiving sub-condenser lens (422) is positioned above the inner receiving condenser lens (412). The outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) serve to further expand the receiving range of the return light incident in the vertical direction.

[0084] More specifically, the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can receive and focus the return light incident over a range of 40° in the vertical direction. In other words, there is a limit to the range in which the return light incident in the vertical direction can be received through the outermost receiving condenser lens (411) and the inner receiving condenser lens (412). Therefore, by positioning the outermost receiving sub-condenser lens (421) above the outermost receiving condenser lens (411) and positioning the inner receiving sub-condenser lens (422) above the inner receiving condenser lens (412), the receiving range of the return light incident in the vertical direction can be expanded.

[0085] For example, the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can receive and focus the return light incident over a range of 40° in the vertical direction. Similarly, the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) can receive and focus the return light incident over a range of 40° in the vertical direction. Accordingly, the omnidirectional lidar device (1000-2) can receive and focus the return light incident over a range of 80° in the vertical direction.

[0086] The outermost receiving sub-condenser lens (421) can alleviate the dispersion phenomenon of the returned light by focusing the returned light. However, the outermost receiving sub-condenser lens (421) alone may have limitations in alleviating the dispersion phenomenon of the returned light. Therefore, it may be desirable to provide both the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422).

[0087] In order to sufficiently alleviate the phenomenon of the return light spreading, the focus of the outermost receiving sub-condenser lens (421) and the focus of the inner receiving sub-condenser lens (422) need to be appropriately adjusted. In order to adjust the focus of the receiving sub-condenser lenses (421, 422), the distance between the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) must be a preset distance, and the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) must be fixed at positions so as to have the preset distance. In order to facilitate such distance and position setting, the receiving condenser lens unit (400) may additionally include an outermost housing (430: 430-2) and an inner housing (440: 440-2) as illustrated in FIGS. 5A, 5B, and 6.

[0088] FIG. 5a is a drawing showing an outermost receiving condenser lens (411) and an outermost receiving sub-condenser lens (421) held in the outermost housing (430-2), and FIG. 5b is a drawing showing an inner receiving condenser lens (412) and an inner receiving sub-condenser lens (422) held in the inner housing (440-2). In addition, FIG. 6 is a drawing showing an inner housing (440-2) shown in FIG. 5b arranged inside the outermost housing (430-2) shown in FIG. 5a.

[0089] As illustrated in FIG. 5A, the outermost housing (430-2) may be a hollow cylindrical shape and may hold an outermost receiving condenser lens (411) among a plurality of receiving condenser lenses (411, 412) and an outermost receiving sub-condenser lens (421) among a plurality of receiving sub-condenser lenses (421, 422). More specifically, the outermost receiving condenser lens (411) and the outermost receiving sub-condenser lens (421) may be held in a column portion of the cylindrical outermost housing (430-2).

[0090] When return light is incident from the outside of the outermost housing (430-2) onto the outermost receiving condenser lens (411), the outermost receiving condenser lens (411) focuses the return light and transmits it to the inner receiving condenser lens (412) located on the inside of the outermost housing (430-2). In addition, when return light is incident from the outside of the outermost housing (430-2) onto the outermost receiving sub-condenser lens (421), the outermost receiving sub-condenser lens (421) focuses the return light and transmits it to the inner receiving sub-condenser lens (422) located on the inside of the outermost housing (430-2).

[0091] Fig. 5a illustrates a front view of the outermost housing (430-2). Five outermost receiving condenser lenses (411) may be provided in front of the outermost housing (430-2) and four may be provided in the rear of the outermost housing (430-2). In addition, five outermost receiving sub-condenser lenses (421) may be provided in front of the outermost housing (430-2) and four may be provided in the rear of the outermost housing (430-2).

[0092] As illustrated in FIG. 5b, the inner housing (440-2) may also be hollow and cylindrical. The height of the inner housing (440-2) may be the same as the height of the outermost housing (430-2), but the diameter of the inner housing (440-2) is smaller than the diameter of the outermost housing (430-2).

[0093] The inner housing (440-2) can have an inner receiving condenser lens (412) among a plurality of receiving condenser lenses (411, 412) and an inner receiving sub-condenser lens (422) among a plurality of receiving sub-condenser lenses (421, 422). More specifically, the inner receiving condenser lens (412) and the inner receiving sub-condenser lens (422) can be held in a column portion of the cylindrical inner housing (440-2).

[0094] When the return light passes through the outermost receiving condenser lens (411) and enters the inner receiving condenser lens (412), the inner receiving condenser lens (412) focuses the return light and transmits it to the receiving mirror (500) located on the inner side of the inner housing (440-2). In addition, when the return light passes through the outermost receiving sub-condenser lens (421) and enters the inner receiving sub-condenser lens (422), the inner receiving sub-condenser lens (422) focuses the return light and transmits it to the receiving mirror (500) located on the inner side of the inner housing (440-2).

[0095] Fig. 5b illustrates a front view of the inner housing (440-2). Five inner receiving condenser lenses (412) may be provided at the front of the inner housing (440-2) and four at the rear of the inner housing (440-2). In addition, five inner receiving sub-condenser lenses (422) may be provided at the front of the inner housing (440-2) and four at the rear of the inner housing (440-2).

[0096] As illustrated in FIG. 6, the inner housing (440-2) is arranged inside the outermost housing (430-2), and at this time, the outermost receiving condenser lens (411) held by the outermost housing (430-2) and the inner receiving condenser lens (412) held by the inner housing (440-2) can be arranged to have a common horizontal center axis (○'). In addition, the outermost receiving sub-condenser lens (421) held by the outermost housing (430-2) and the inner receiving sub-condenser lens (422) held by the inner housing (440-2) can be arranged to have another common horizontal center axis (○").

[0097] For reference, a light emitting unit (100), a scanning mirror (200), a light detecting unit (600), and a detection focusing lens unit (800) may be positioned at the lower portions of the outermost housing (430-2) and the inner housing (440-2) illustrated in FIG. 6, and an upper mirror (300) may be positioned at the upper portions of the outermost housing (430-2) and the inner housing (440-2). In addition, a receiving mirror (500) and an expansion lens unit (700) may be positioned at the inner portion of the inner housing (440-2) illustrated in FIG. 6.

[0098] Due to the outermost housing (430-2) and the inner housing (440-2), the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can be fixed at fixed positions, and thus the distance between the outermost receiving condenser lens (411) and the inner receiving condenser lens (412) can be always maintained constant. In addition, due to the outermost housing (430-2) and the inner housing (440-2), the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) can be fixed at fixed positions, and thus the distance between the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422) can also be always maintained constant. That is, when the receiving condenser lens unit (400) includes the outermost housing (430-2) and the inner housing (440-2), the focus of the receiving condenser lens (411, 412, 421, 422) can be adjusted with high accuracy, and accordingly, the phenomenon of the return light spreading can be greatly alleviated compared to the past, and the return light detection efficiency of the light detection unit (600) can be improved.

[0099] In addition, simply placing the inner housing (440-2) inside the outermost housing (430-2) completes the alignment between the outermost receiving condenser lens (411) and the inner receiving condenser lens (412), and also completes the alignment between the outermost receiving sub-condenser lens (421) and the inner receiving sub-condenser lens (422), so there is no need to individually place the receiving condenser lenses (411, 412, 421, 422) at fixed positions. Accordingly, when the receiving condenser lens unit (400) includes the outermost housing (430-2) and the inner housing (440-2), the time for manufacturing the omnidirectional lidar device (1000-2) can be shortened, and the cost required for manufacturing can be reduced.

[0100] Although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art will appreciate that various modifications and variations can be made based on this description.

[0101] For example, the above description is intended to explain that the receiving condenser lens unit (400) has only two housings (430, 440). However, as long as the housing is positioned on the inside of the outermost housing (430), it may correspond to the inner housing according to the present invention, and accordingly, the number of housings included in the receiving condenser lens unit (400) may be three or more. In addition, the above description is intended to explain that two condenser lens layers are formed when a plurality of receiving sub-condenser lenses (421, 422) are positioned on top of a plurality of receiving condenser lenses (411, 412). However, as long as the receiving condenser lenses are positioned on top of a plurality of receiving condenser lenses (411, 412), they may correspond to a plurality of receiving sub-condenser lenses according to the present invention, and accordingly, three or more condenser lens layers may be formed. Therefore, the technical idea of ​​the present invention should be understood only by the scope of the claims, and all equivalent or equivalent modifications thereof will be considered to fall within the scope of the technical idea of ​​the present invention.

[0102] [Explanation of symbols]

[0103] 100: Light emitting part

[0104] 200: Scan Mirror

[0105] 300: Upper mirror

[0106] 400: Receiver focusing lens section

[0107] 411: Outermost receiving condenser lens

[0108] 412: Inner receiving condenser lens

[0109] 421: Sub-condenser lens for outermost receiving

[0110] 422: Sub-condenser lens for inner reception

[0111] 430 (430-1, 430-2): Outermost housing

[0112] 440 (440-1, 440-2): Inner housing

[0113] 500: Receiver Mirror

[0114] 600: Light detection unit

[0115] 700: Extension lens section

[0116] 711: First extension lens

[0117] 721: Second Expansion Lens

[0118] 800: Concentrating lens for detection

[0119] 811: First detection condenser lens

[0120] 821: Second detection condenser lens

[0121] 1000 (1000-1, 1000-2): Omnidirectional lidar device of scan type

Claims

1. As an omnidirectional lidar device of scan type, A light emitting unit that emits light of a predetermined wavelength band; A scan mirror installed on the path of light emitted from the light emitting portion so that the direction of its reflective surface varies over time, and which scans the light emitted from the light emitting portion and reflects it upward; An upper mirror positioned above the scan mirror and reflecting light reflected by the scan mirror to the outside of the omnidirectional lidar device; A receiving focusing lens unit that focuses light reflected and returned by a reflector located outside the above omnidirectional lidar device; A receiving mirror that reflects downward the light focused by the receiving focusing lens unit; and An omnidirectional lidar device of a scan type, which is positioned below the receiving mirror and includes a light detection unit that detects light reflected by the receiving mirror.

2. In paragraph 1, The above scan type omnidirectional lidar device, An omnidirectional lidar device of a scan type further comprising an expansion lens unit positioned between the scan mirror and the upper mirror and expanding the angle of view of light reflected by the scan mirror.

3. In paragraph 2, The above extension lens part, An omnidirectional lidar device of the scan type comprising a plurality of expansion lenses arranged in a perpendicular direction to each other.

4. In paragraph 1, The above receiving condenser lens part is, An omnidirectional lidar device of a scan type including a plurality of receiving condenser lenses arranged in a circular manner based on a vertical central axis of the above omnidirectional lidar device.

5. In paragraph 4, The above receiving condenser lens part is, An outermost housing having a receiving condenser lens located at the outermost position among the above-mentioned plurality of receiving condenser lenses; and It further includes an inner housing having a receiving condenser lens located inside the outermost receiving condenser lens among the plurality of receiving condenser lenses, The inner housing is arranged inside the outermost housing, An omnidirectional lidar device of a scan type, characterized in that the receiving condenser lens located at the outermost side and the receiving condenser lens located at the inner side are arranged to have a common horizontal center axis.

6. In paragraph 4, The above receiving condenser lens part is, An omnidirectional lidar device of a scan type further comprising a plurality of receiving sub-condensing lenses positioned above the plurality of receiving condensing lenses and arranged around the vertical central axis of the omnidirectional lidar device.

7. In paragraph 6, The above receiving condenser lens part is, An outermost housing having a receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses and a receiving sub-condenser lens positioned at the outermost end among the plurality of receiving sub-condenser lenses; and It further includes an inner housing having a receiving condenser lens positioned inward compared to the receiving condenser lens positioned at the outermost end among the plurality of receiving condenser lenses, and a receiving sub-condenser lens positioned inward compared to the receiving sub-condenser lens positioned at the outermost end among the plurality of receiving sub-condenser lenses, The inner housing is arranged inside the outermost housing, The receiving condenser lens located at the outermost side and the receiving condenser lens located at the inner side are arranged to have a common lens center axis. An omnidirectional lidar device of a scan type, characterized in that the receiving sub-condenser lens located at the outermost side and the receiving sub-condenser lens located at the inner side are arranged to have another common lens center axis.

8. In paragraph 1, The above scan type omnidirectional lidar device, An omnidirectional lidar device of a scan type further comprising a focusing lens unit for focusing light reflected by the receiving mirror, the focusing lens unit being positioned between the scanning mirror and the light detection unit.

9. In paragraph 8, The above detection focusing lens part is, An omnidirectional lidar device of the scanning type comprising a plurality of detection focusing lenses arranged in a perpendicular direction to each other.

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