Lidar apparatus

Abstract

A lidar apparatus according to an embodiment of the present invention includes: a light-emitting unit for emitting an optical signal to an object; and a light-receiving unit for receiving an optical signal reflected from the object. The light-receiving unit includes: an image sensor including a light-receiving surface having a long axis in a first direction; a first lens unit disposed on the image sensor; a window disposed on the first lens unit; and a filter disposed between the image sensor and the window, wherein at least one of the filter or the window is tilted, with respect to the light-receiving surface of the image sensor, about the virtual first axis parallel to the long axis or a second axis inclined with respect to the first axis.

Description

Lidar device

[0001] The present invention relates to a lidar device.

[0002] LiDAR (Light Detection and Ranging) measures the distance to an object or creates a visual representation of it using laser pulses emitted from a light source and reflected back at the target object. LiDAR is applied to a variety of technologies that require three-dimensional imaging. For example, LiDAR can be applied to various fields such as meteorology, aviation, space, and automotive. Recently, LiDAR's role in the autonomous driving field has been rapidly increasing.

[0003] In general, the light emitting part of the lidar generates an output light signal and irradiates it on an object, the light receiving part receives an input light signal reflected from the object, and the information generating part generates information about the object using the input light signal received by the light receiving part.

[0004] Lidar can be broadly categorized into mechanical and fixed lidar. Mechanical lidar can achieve a 360-degree field of view by rotating the light emitter and light receiver. Fixed lidar can be, for example, MEMS (Micro Electro Mechanical System) lidar, flash lidar, or OPA (Optical Phase Array) lidar. In MEMS lidar, the tilt angle of the mirror can be slightly changed by electrical signals. Flash lidar uses an optical flash, and a single large-area laser pulse can illuminate the forward environment. In OPA, an optical phase modulator controls the speed of light passing through the lens, thereby controlling the optical wavefront shape.

[0005] Typically, the light-receiving unit of a mechanical lidar comprises a one-dimensional array of image sensors, which are prone to ghosting due to double reflections. Noise from ghosting can provide the lidar with false information, rather than light reflected from actual objects, which can create phantom images in the point cloud, the object detection result.

[0006] The technical problem to be achieved by the present invention is to provide a lidar device that outputs parallel light to minimize noise due to ghosting and prevent loss of irradiated light.

[0007] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the description below.

[0008] According to an embodiment of the present invention for achieving the above-described object, a lidar device includes a light emitting unit that irradiates an optical signal to an object, and a light receiving unit that receives an optical signal reflected from the object, wherein the light receiving unit includes an image sensor including a light receiving surface having a long axis in a first direction, a first lens unit disposed on the image sensor, a window disposed on the first lens unit, and a filter disposed between the image sensor and the window, and at least one of the filter and the window is tilted with respect to a virtual first axis parallel to the long axis of the light receiving surface of the image sensor or a second axis inclined with respect to the first axis.

[0009] The image sensor includes a pixel array arranged along the first direction and a second direction perpendicular to the first direction, the number of pixels arranged along the first direction is greater than the number of pixels arranged along the second direction, and at least one of the filter and the window can be tilted about the first direction as a rotation axis.

[0010] The above filter and the above window can each be tilted about the first direction as a rotation axis.

[0011] The above filter and the above window can be tilted within a range of 0.5 to 5 degrees with the first direction as the rotation axis.

[0012] The above filter and the above window can be tilted within a range of 1 to 3 degrees about the first direction as a rotation axis.

[0013] One of the filter and the window can be tilted clockwise with the first direction as the rotation axis, and the other of the filter and the window can be tilted counterclockwise with the first direction as the rotation axis.

[0014] A micro lens array is disposed between the image sensor and the first lens unit and has a long axis in the first direction, and at least one of the filter and the window can be tilted relative to the micro lens array about an imaginary axis parallel to the long axis of the micro lens array.

[0015] The micro lens array includes a plurality of micro lenses arranged along the first direction and a second direction perpendicular to the first direction, and the number of micro lenses arranged along the first direction may be greater than the number of micro lenses arranged along the second direction.

[0016] The image sensor may include an m*n pixel array, and a ratio of m to n may be 8 or greater.

[0017] The filter may include a filter surface including the first axis and the second axis.

[0018] The window may include a window surface including the first axis and the second axis.

[0019] The first axis may be spaced apart from the longitudinal axis of the image sensor in the optical axis direction.

[0020] The second axis may be perpendicular to the first axis.

[0021] A lidar device including a light receiving unit that rotates about a rotation axis parallel to a first direction, wherein the light receiving unit includes an image sensor, a first lens unit that is arranged spaced apart from the image sensor in an optical axis direction that is perpendicular to the first direction, a window that is arranged spaced apart from the filter in the optical axis direction, and a filter that is arranged between the image sensor and the window, wherein at least one of the filter and the window is tilted about a first axis parallel to the first direction.

[0022] The image sensor may have a long axis in the first direction.

[0023] The image sensor may be arranged to face the optical axis direction, and at least one of the filter and the window may be arranged to face a direction that is offset from the optical axis direction.

[0024] A micro lens array is included that is arranged between the image sensor and the first lens unit, and the micro lens array can have a long axis in the first direction.

[0025] A light emitting unit that irradiates an optical signal to an object, and a light receiving unit that receives an optical signal reflected from the object, wherein the light receiving unit includes an image sensor including a light receiving surface, a first lens unit disposed on the image sensor, a window disposed on the first lens unit, and a filter disposed between the image sensor and the window, and at least one of the filter and the window is tilted with respect to the light receiving surface of the image sensor.

[0026] At least one of the filter and the window may not be parallel to the light-receiving surface.

[0027] The image sensor may include a pixel array including a light-receiving surface and a micro lens array disposed on the pixel array.

[0028] At least one of the filter and the window can be tilted relative to the light-receiving surface of the microlens array.

[0029] A second lens unit that collects and outputs light irradiated from a light source unit according to an embodiment, the second lens unit including a first lens surface facing the light source unit and a second lens surface arranged in an opposite direction to the first lens surface, the first lens surface including a plurality of first unit patterns arranged in the first direction, the first unit patterns extending along a second direction perpendicular to the first direction, and the second lens surface including a second unit pattern having a long axis extending along the first direction.

[0030] The first lens surface and the second lens surface may be asymmetrical to each other.

[0031] The above second unit pattern may be aspherical.

[0032] The first unit pattern may have an arc shape based on an axis parallel to the second direction, and the second unit pattern may have an arc shape based on an axis parallel to the first direction.

[0033] The first unit pattern may be arranged such that the distance between the outermost point in the radial direction and the axis parallel to the second direction is the same along the second direction, based on the third direction perpendicular to the first direction and the second direction.

[0034] A recessed portion that is recessed in a direction from the first lens surface toward the second lens surface may be arranged between the two adjacent first unit patterns.

[0035] The distance between the plurality of recessed portions along the second direction may be the same.

[0036] The second lens surface may be arranged such that the distance between the radially outermost point based on the third direction and the axis parallel to the first direction is the same along the first direction.

[0037] The effective focal length (EFL) of the second lens surface may be 4 to 8 times the effective focal length (EFL) of the first lens surface.

[0038] The F number of the second lens surface may be 0.2 to 0.5 times the F number of the first lens surface.

[0039] A lidar device according to an embodiment comprises a light source unit that irradiates light and a second lens unit that collects and outputs light irradiated from the light source unit, the first lens surface facing the light source unit and a second lens surface arranged in an opposite direction to the first lens surface, the first lens surface including a plurality of first unit patterns arranged in a first direction, the first unit patterns extending along a second direction perpendicular to the first direction, the second lens surface including a second unit pattern having a long axis extending along the first direction, and a second lens unit that collects and outputs light irradiated from the light source unit.

[0040] The above light source unit may include a plurality of light sources arranged along the first direction and irradiating light in a third direction perpendicular to the first direction and the second direction.

[0041] The first unit pattern has an arc shape based on an axis parallel to the second direction, and can overlap with any one of the plurality of light sources in the third direction.

[0042] The length of the light source in the first direction may be shorter than the length of the first lens surface in the first direction.

[0043] When a reflection type volume Bragg grating (VBG) is arranged spaced apart from the second lens unit in the third direction, light reflected from the volume Bragg grating can travel to the light source unit along the same optical path.

[0044] The plurality of light sources can irradiate light having a wavelength band of 1350 nm to 1450 nm.

[0045] A lidar device according to an embodiment of the present invention for solving the above problem can have the effect of outputting parallel light to minimize noise due to ghosting and prevent loss of irradiated light.

[0046] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0047] In addition, the effects of the present invention may be described in more detail in the detailed description of the present invention, and may not necessarily be limited to what is presented above.

[0048] The summary set forth above, as well as the detailed description of preferred embodiments of the present application described below, will be better understood when read in conjunction with the accompanying drawings.

[0049] For the purpose of illustrating the present invention, preferred embodiments are shown in the drawings.

[0050] However, it should be understood that the present application is not limited to the precise arrangements and means illustrated.

[0051] FIG. 1 is a block diagram of a lidar device according to one embodiment of the present invention.

[0052] FIG. 2 is a top view of an image sensor according to an embodiment of the present invention.

[0053] Figure 3 is a bottom view of a micro lens array according to an embodiment of the present invention.

[0054] FIG. 4 is a cross-sectional view along a first direction of an image sensor and a micro lens array according to an embodiment of the present invention.

[0055] FIG. 5 is a cross-sectional view of an image sensor and a micro lens array according to an embodiment of the present invention in a second direction.

[0056] Fig. 6 is a cross-sectional view of a light receiving unit according to an embodiment of the present invention along a first direction.

[0057] Fig. 7 is a cross-sectional view of a light receiving unit according to an embodiment of the present invention in a second direction.

[0058] Figure 8 is an example of a ghost image.

[0059] Figure 9 is a light path layout for simulating the cause of ghost occurrence.

[0060] Figure 10 is the result of simulating the cause of ghost occurrence.

[0061] Figure 11 shows the simulation results according to the tilt of the window and filter.

[0062] Figure 12 shows the results of performing ghost analysis on an object at different angles when neither the window nor the filter is tilted, and when the window is not tilted and only the filter is tilted by 2 degrees.

[0063] Figure 13 shows the results of performing ghost analysis for each angle of an object while tilting the window within a range of -2 degrees to 2 degrees with the filter tilted by 2 degrees.

[0064] Fig. 14 is a drawing illustrating a light emitting unit according to an embodiment of the present invention.

[0065] FIG. 15 is a drawing illustrating a first side of a lidar device according to an embodiment of the present invention.

[0066] FIG. 16 is a drawing illustrating a second side of a lidar device according to an embodiment of the present invention.

[0067] FIG. 17 is a drawing illustrating a first unit pattern of a lidar device according to an embodiment of the present invention.

[0068] FIG. 18 is a drawing illustrating a second unit pattern of a lidar device according to an embodiment of the present invention.

[0069] FIG. 19 is a drawing illustrating the relationship between a light source and a first surface of a lidar device according to an embodiment of the present invention.

[0070] FIG. 20 is a drawing illustrating a first unit pattern and a light-emitting portion of a lidar device according to an embodiment of the present invention.

[0071] FIG. 21 is a drawing illustrating an optical path through a first surface of a lidar device according to an embodiment of the present invention.

[0072] FIG. 22 is a drawing illustrating an optical path through a second surface of a lidar device according to an embodiment of the present invention.

[0073] FIG. 23 is a drawing illustrating the focus of a lidar device according to an embodiment of the present invention.

[0074] FIG. 24 is a drawing illustrating a propagating optical path and a reflected optical path through a first surface of a lidar device according to an embodiment of the present invention.

[0075] FIG. 25 is a drawing illustrating a propagating optical path and a reflected optical path through a second surface of a lidar device according to an embodiment of the present invention.

[0076] Fig. 26 is a perspective view of a lidar system according to an embodiment of the present invention.

[0077] Figure 27 is an exploded view of a lidar system according to an embodiment of the present invention.

[0078] Figure 28 is an exploded view of a lidar device according to an embodiment of the present invention.

[0079] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0080] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0081] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0082] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0083] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0084] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

[0085] These terms are intended only to distinguish one component from another, and are not intended to limit the nature, order, or sequence of the component.

[0086] And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, it may include not only cases where the component is directly connected, coupled or connected to the other component, but also cases where the component is 'connected', 'coupled' or 'connected' by another component between the component and the other component.

[0087] Additionally, when described as being formed or arranged "above or below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below", it can include the meaning of a downward direction as well as an upward direction based on one component.

[0088] The lidar device according to an embodiment of the present invention may refer to a lidar device mounted on a vehicle to measure the distance between the vehicle and an object, but is not limited thereto. The lidar device according to an embodiment of the present invention may extract depth information using the Time of Flight (ToF) principle or the phase shift principle. In this specification, the lidar device may also be referred to as an information generating device, a depth information generating device, or a camera device.

[0089] FIG. 1 is a block diagram of a lidar device according to one embodiment of the present invention.

[0090] Referring to FIG. 1, a lidar device (1000) according to an embodiment of the present invention includes a light emitting unit (100), a light receiving unit (200), an information generating unit (300), and a control unit (400).

[0091] The light emitting unit (100) can generate and output an output light signal in the form of a pulse wave or a continuous wave. The continuous wave may be in the form of a sinusoid wave or a square wave. By generating the output light signal in the form of a pulse wave or a continuous wave, the lidar device (1000) can detect a time difference or a phase difference between the output light signal output from the light emitting unit (100) and the input light signal reflected from the target area and then input to the light receiving unit (200). In this specification, the output light refers to light output from the light emitting unit (100) and incident on an object, and the input light refers to light output from the light emitting unit (100) and reaching the target area, reflected from the target area, and then input to the light receiving unit (200). From the perspective of the target area, the output light may be incident light, and the input light may be reflected light. In this specification, the target area may be used interchangeably with an object or a thing.

[0092] The light emitting unit (100) includes a light source unit (110) and a lens unit (120).

[0093] The light source unit (110) generates and outputs a laser pulse. The light source unit (110) may use a light emitting diode (LED), and may have a form in which a plurality of light emitting diodes are arranged according to a certain pattern. Alternatively, the light source unit (110) may include an organic light emitting diode (OLED) or a laser diode (LD). Alternatively, the light source unit (110) may be a vertical cavity surface emitting laser (VCSEL). A VCSEL is one of laser diodes that converts an electrical signal into an optical signal, and can output a wavelength of about 800 to 1000 nm, for example, about 850 nm or about 940 nm. The light source unit (110) generates an output optical signal in the form of a pulse wave or a continuous wave by repeating blinking (on / off) at a certain time interval. The certain time interval may be the frequency of the output optical signal. Alternatively, the light source unit (110) includes a plurality of light sources (111), and the plurality of light sources (111) can irradiate light having a wavelength band of 1350 nm to 1450 nm, and the plurality of light sources (111) can be light emitting diodes (LEDs) as described above.

[0094] The lens unit (120) can collect light output from the light source unit (110) and output the collected light to the outside. The lens unit (120) can be arranged above the light source unit (110) and spaced apart from the light source unit (110). Here, the upper part of the light source unit (110) can mean the side from which light is output from the light source unit (110). The lens unit (120) can include at least one lens, and when the lens unit (120) includes a plurality of lenses, each lens can be aligned with respect to a central axis to form an optical system. Here, the central axis can be the same as the optical axis of the optical system. The lens unit (120) can also include a diffusion member that receives light output from the light source unit (110) and then refracts or diffracts the received light and outputs it. This will be described in more detail with reference to the drawings to be described later.

[0095] The light receiving unit (200) can receive an optical signal reflected from the target area. At this time, the received optical signal may be an optical signal output by the light emitting unit (100) reflected from the target area.

[0096] The light receiving unit (200) includes an image sensor, a lens unit (230) placed on the image sensor, and a filter.

[0097] An optical signal reflected from a target area can pass through a lens unit (230) of a light receiving unit (200). The optical axis of the lens unit (230) of the light receiving unit (200) can be aligned with the optical axis of an image sensor. A filter can be placed on an optical path between the target area and the image sensor. The filter can filter light having a predetermined wavelength range. The filter can pass light of a specific wavelength. For example, the filter can pass light in an infrared band and block light outside of an infrared band. The image sensor can receive an optical signal and output the received optical signal as an electrical signal. The image sensor can detect light of a wavelength corresponding to the wavelength of light output by the light emitting unit (100). For example, the image sensor can detect light in an infrared band.

[0098] An image sensor may be configured with a structure in which multiple pixels are arranged in a grid shape.

[0099] The light receiving unit (200) and the light emitting unit (100) may be arranged side by side. The light receiving unit (200) may be arranged next to the light emitting unit (100). The light receiving unit (200) may be arranged to face the same direction as the light emitting unit (100). Alternatively, the light receiving unit (200) and the light emitting unit (100) may be arranged to face different directions. When the light receiving unit (200) and the light emitting unit (100) are arranged to face different directions, an optical path conversion member may be further arranged between the light receiving unit (200) and the light emitting unit (100).

[0100] The information generating unit (300) generates information about a target area using an input light signal input to the light receiving unit (200). The information about the target area may include three-dimensional information about the target area. For example, the information about the target area may include depth information about the target area or shape information about the target area. For example, the information generating unit (300) may calculate depth information about an object using the flight time it takes for an output light signal output from the light emitting unit (100) to be input to the light receiving unit (200) after being reflected from an object. For example, the information generating unit (300) may calculate a time difference between an output light signal and an input light signal using an electrical signal received by an image sensor, and may calculate a distance between the target area and the LIDAR device (1000) using the calculated time difference. For example, the information generating unit (300) may calculate a phase difference between an output light signal and an input light signal using an electrical signal received from an image sensor, and may calculate a distance between the target area and the LIDAR device (1000) using the calculated phase difference.

[0101] The control unit (400) controls the operation of the light emitting unit (100), the light receiving unit (200), and the information generating unit (300). The information generating unit (300) and the control unit (400) may be implemented in the form of a PCB (printed circuit board). In addition, the information generating unit (300) and the control unit (400) may be implemented in the form of other configurations. Alternatively, the control unit (400) may be included in a terminal or vehicle in which the lidar device (1000) according to an embodiment of the present invention is installed. For example, the control unit (400) may be implemented in the form of an application processor (AP) of a smartphone in which the lidar device (1000) according to an embodiment of the present invention is installed, or in the form of an electronic control unit (ECU) of a vehicle in which the lidar device (1000) according to an embodiment of the present invention is installed.

[0102] The lidar device (1000) according to an embodiment of the present invention may be a mechanical lidar that rotates 360°. To this end, the lidar device (1000) may further include a rotating unit (500). The rotating unit (500) may further include a plate (510) on which a light-emitting unit (100) and a light-receiving unit (200) are mounted, and a motor (520) that rotates the plate (510). Accordingly, the lidar device (1000) may have a 360° FOV.

[0103] In order to distinguish between the lens unit (230) of the light receiving unit (200) and the lens unit (120) of the light emitting unit (100) in the detailed description of the present invention to be described later, the lens unit (230) of the light receiving unit (200) will be described as the first lens unit (230), and the lens unit (120) of the light emitting unit (100) will be described as the second lens unit (120).

[0104] FIG. 2 is a top view of an image sensor according to an embodiment of the present invention, FIG. 3 is a bottom view of a micro lens array according to an embodiment of the present invention, FIG. 4 is a cross-sectional view of an image sensor and a micro lens array according to an embodiment of the present invention along a first direction, FIG. 5 is a cross-sectional view of an image sensor and a micro lens array according to an embodiment of the present invention along a second direction, FIG. 6 is a cross-sectional view of a light receiving unit according to an embodiment of the present invention along a first direction, and FIG. 7 is a cross-sectional view of a light receiving unit according to an embodiment of the present invention along a second direction.

[0105] Referring to FIGS. 2 to 7, a light receiving unit (200) included in a lidar device (1000) according to an embodiment of the present invention includes an image sensor (210), a first lens unit (230) disposed on the image sensor (210), a window (250) disposed on the first lens unit (230), and a filter (240) disposed between the image sensor (210) and the window (250). Although the filter (240) is illustrated as being disposed between the first lens unit (230) and the window (250) in this specification, it is not limited thereto, and the filter (240) may be disposed between the image sensor (210) and the window (250). According to another embodiment of the present invention, a micro lens array (220) disposed on the image sensor (210) may be further included. That is, the light receiving unit (200) included in the lidar device (1000) according to another embodiment of the present invention may include an image sensor (210), a micro lens array (220) disposed on the image sensor (210), a first lens unit (230) disposed on the micro lens array (220), a window (250) disposed on the first lens unit (230), and a filter (240) disposed between the image sensor (210) and the window (250).

[0106] According to an embodiment of the present invention, the image sensor (210) includes an active area and a non-active area surrounding the active area. The active area is a light-receiving surface including a pixel array. Here, the pixel array may be a single photon avalanche detector (SPAD) array, and the SPAD array may include a plurality of SPADs. When the SPAD receives an optical signal, photons can be detected by the avalanche phenomenon.

[0107] Here, the image sensor (210) includes a pixel array arranged along a first direction and a second direction, and has a long axis in the first direction. That is, the number of pixels arranged along the first direction in the image sensor (210) may be greater than the number of pixels arranged along the second direction. For example, the image sensor (210) according to an embodiment of the present invention includes an m*n pixel array, where m may be greater than n. When the ratio of m to n is 8 or more, it may be referred to as a one-dimensional pixel array or a one-dimensional SPAD array.

[0108] According to an embodiment of the present invention, the image sensor (210) may include a one-dimensional pixel array. For example, the image sensor (210) according to an embodiment of the present invention may include a 16*2 pixel array, a 32*2 pixel array, a 64*2 pixel array, a 128*2 pixel array, a 256*2 pixel array, a 512*2 pixel array, or a 1024*2 pixel array.

[0109] When the light receiving unit (200) further includes a micro lens array (220), the micro lens array (220) is arranged on the image sensor (210) to be spaced apart from the image sensor (210). The micro lens array (220) includes a first surface (220A) arranged to face the image sensor (210) and a second surface (220B) opposite the first surface (220A), and a plurality of micro lenses protrude from the first surface (220A) to face the image sensor (210). For convenience of explanation, the first surface (220A) of the micro lens array (220) may be referred to as the lower surface of the micro lens array (220), and the second surface (220B) of the micro lens array (220) may be referred to as the upper surface of the micro lens array (220).

[0110] A first surface (220A) of a micro lens array (220) according to an embodiment of the present invention includes an effective area (220A1) including a plurality of micro lenses corresponding to a pixel array of an image sensor (210), a buffer area (220A2) including a plurality of micro lenses arranged to surround the effective area (220A1), and a peripheral area (220A3) arranged to surround the buffer area (220A2).

[0111] Here, the effective area (220A1) can be matched one-to-one with the pixel array. That is, when the image sensor (210) includes an m*n pixel array, the effective area (220A1) includes m*n micro lenses, and the pixels of the image sensor (210) and the micro lenses of the effective area (220A1) can be matched one-to-one. Accordingly, among the optical signals incident on the light receiving unit (200), the optical signals incident on the effective area (220A1) can be detected by the image sensor (210) and used to recognize an object. The optical signals incident on the light receiving unit (200) can be collected by the micro lenses of the effective area (220A1) of the micro lens array (220), thereby increasing the optical reception efficiency for each pixel. Accordingly, the micro lens array (220) may also be referred to as a sensor window.

[0112] Meanwhile, the buffer region (220A2) may be arranged to surround the effective region (220A1) around the effective region (220A1). For example, if the image sensor (210) includes an m*n pixel array and the effective region (220A1) includes m*n micro lenses, the first surface (220A) of the micro lens array (220) may include a total of (m+2a)*(n+2b) micro lenses, including the buffer region (220A2). Here, a and b may be the same or different. For example, a and b may be 1 or more and 10 or less, preferably 1 or more and 5 or less, and more preferably 2 or more and 3 or less. For example, a may be 3 and b may be 2. In this way, if the first surface (220A) of the micro lens array (220) includes a buffer area (220A2) surrounding the effective area (220A1), the light collection efficiency of the effective area (220A1) can be improved and the loss of the optical signal can be reduced.

[0113] Meanwhile, the peripheral region (220A3) may be arranged to surround the buffer region (220A2) around the buffer region (220A2). At this time, the peripheral region (220A3) may be a flat surface. Accordingly, the micro lens array (220) may be attached to a structure within the image sensor (210) or the light receiving unit (200) through the peripheral region (220A3).

[0114] Referring to FIGS. 6 and 7, a first lens unit (230), a filter (240), and a window (250) are disposed on the image sensor (210). Alternatively, a first lens unit (230), a filter (240), and a window (250) are disposed on the image sensor (210) and the micro lens array (220). Here, the first lens unit (230) may include a plurality of lenses. For example, the first lens unit (230) may include two lenses disposed to be spaced apart from each other, but is not limited thereto. The filter (240) disposed on the first lens unit (230) may be a bandpass filter. For example, it may be a bandpass filter that transmits only IR light signals among the light signals input to the receiver (200). Although not illustrated, the first lens unit (230) and the filter (240) may be disposed on a lens barrel. Although the image sensor (210), micro lens array (220), first lens unit (230), and filter (240) are shown to be arranged sequentially, this is not limited thereto, and the image sensor (210), micro lens array (220), filter (240), and first lens unit (230) may be arranged in that order.

[0115] The window (250) is positioned outside the lens barrel, and the light signal reflected from the object passes through the window (250) and is sequentially incident on the filter (240), the first lens unit (230), the micro lens array (220), and the image sensor (210). Accordingly, the window (250) may be referred to as a glass window or an external window. The light signal output from the light emitting unit (100) may also be output to the outside through the window (250).

[0116] Meanwhile, in the process of receiving an optical signal reflected from an object through a window (250), a filter (240), and a first lens unit (230) to an image sensor (210), the optical signal may be reflected or refracted by the window (250), the filter (240), and the first lens unit (230), which may cause a ghost phenomenon due to a virtual point cloud. Fig. 8 is an example of a ghost image.

[0117] According to an embodiment of the present invention, at least one of the filter (240) and the window (250) is arranged to be tilted based on the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220). Accordingly, at least one of the filter (240) and the window (250) is arranged not to be parallel to the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220), so that the ghost phenomenon can be minimized.

[0118] More specifically, as described above, the image sensor (210) includes a pixel array arranged along a first direction and a second direction, and the number of pixels arranged along the first direction is greater than the number of pixels arranged along the second direction. Similarly, the first surface (220A) of the microlens array (220) includes a plurality of microlenses arranged along the first direction and a second direction perpendicular to the first direction, and the number of microlenses arranged along the first direction may be greater than the number of microlenses arranged along the second direction. Accordingly, the first direction may refer to the long-axis direction of the image sensor (210) or the microlens array (220), and the second direction may refer to the short-axis direction of the image sensor (210) or the microlens array (220).

[0119] Here, at least one of the filter (240) and the window (250) is tilted based on a virtual first axis parallel to the first direction, which is the major axis, with respect to the light-receiving surface of the image sensor (210) or a virtual second axis inclined with respect to the first axis. Alternatively, at least one of the filter (240) and the window (250) is tilted based on a virtual first axis parallel to the first direction, which is the major axis, with respect to the effective area of ​​the micro lens array (220) or a virtual second axis inclined with respect to the first axis.

[0120] Here, tilting with respect to the first axis may mean rotation with respect to an axis parallel to the first direction as the rotation axis. That is, tilting with respect to the first axis may mean tilting with respect to the first direction, and may also be expressed as rotation with respect to the first direction as the axis. Here, the virtual first axis may be an axis that is parallel to the long axis of the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220), but is spaced apart from the long axis of the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220) along the optical axis direction. Accordingly, at least one of the filter surface of the filter (240) and the window surface of the window (250) may include the virtual first axis.

[0121] Here, the second axis may be a virtual second axis perpendicular to the first axis. That is, the virtual second axis may be an axis that is parallel to the short axis of the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220), but is spaced apart from the short axis of the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220) along the optical axis direction. Accordingly, at least one of the filter surface of the filter (240) and the window surface of the window (250) may include the virtual second axis.

[0122] Accordingly, in this specification, the virtual first axis or the virtual second axis included in at least one of the filter surface of the filter (240) and the window surface of the window (250) may be referred to as a rotation axis.

[0123] When at least one of the filter (240) and the window (250) is tilted with respect to the first imaginary axis parallel to the first direction, which is the major axis of the light-receiving surface of the image sensor (210), in FIG. 6, which is a cross-sectional view along the first direction of the light-receiving unit (200), the image sensor (210), the filter (240), and the window (250) are shown as being parallel to each other, but in FIG. 7, which is a cross-sectional view along the second direction of the light-receiving unit (200), the filter (240) is shown as being tilted with respect to the image sensor (210), and the window (250) is shown as being tilted with respect to the image sensor (210). That is, referring to FIG. 7, it can be seen that the filter (240) is tilted at a first angle (θ1) with respect to a direction parallel to the image sensor (210), and the window (250) is tilted at a second angle (θ2) with respect to a direction parallel to the image sensor (210).

[0124] According to this, the image sensor (210) is arranged to face the optical axis direction, i.e., the third direction, but the filter (240) and the window (250) can be arranged to face a direction that is different from the optical axis direction, i.e., a direction inclined with respect to the optical axis direction.

[0125] In this way, when the filter (240) and the window (250) are tilted and arranged with the long axis of the light-receiving surface of the image sensor (210) or the effective area of ​​the micro lens array (220), i.e., the first direction, as the rotation axis, ghost images can be removed from the effective area (220A1) of the micro lens array (220).

[0126] Here, the filter (240) and the window (250) can be bonded or fastened in a tilted state about the long axis of the image sensor (210), i.e., the first direction, as the rotational axis. For example, when the filter (240) is placed in the lens barrel, the filter (240) can be bonded to the inner wall of the lens barrel in a tilted state about the long axis of the image sensor (210), i.e., the first direction, as the rotational axis, or can be fixed to the lens barrel by a fastening member. Similarly, the window (250) can be bonded to the housing or support member (not shown) of the lidar device (1000) in a tilted state about the long axis of the image sensor (210), i.e., the first direction, as the rotational axis, or can be fixed to the housing or support member (not shown) by a fastening member.

[0127] According to an embodiment of the present invention, the filter (240) may be tilted clockwise about the rotation axis, and the window (250) may be tilted counterclockwise about the rotation axis. Alternatively, according to an embodiment of the present invention, the filter (240) may be tilted counterclockwise about the rotation axis, and the window (250) may be tilted clockwise about the rotation axis. Alternatively, according to an embodiment of the present invention, the filter (240) may be tilted clockwise about the rotation axis, and the window (250) may be tilted clockwise about the rotation axis. Alternatively, according to an embodiment of the present invention, the filter (240) may be tilted counterclockwise about the rotation axis, and the window (250) may be tilted counterclockwise about the rotation axis.

[0128] According to an embodiment of the present invention, the filter (240) and the window (250) can be tilted within a range of 0.5 to 5 degrees, preferably within a range of 1 to 3 degrees, and more preferably within a range of 1.5 to 2.5 degrees, with respect to the rotation axis. If the filter (240) and the window (250) are rotated below the lower limit of this numerical range with respect to the rotation axis, it is difficult to obtain the effect of ghost prevention, and if they are rotated beyond the upper limit of this numerical range, the amount of light signal incident on the image sensor (210) is reduced, making object recognition difficult.

[0129] According to an embodiment of the present invention, the angle (θ1) at which the filter (240) is tilted with respect to the rotation axis may be the same as or different from the angle (θ2) at which the window (250) is tilted with respect to the rotation axis. For example, the tilting direction of the filter (240) and the tilting direction of the window (250) may be the same, and the tilting angle of the filter (240) and the tilting angle of the window (250) may be the same. Alternatively, the tilting direction of the filter (240) and the tilting direction of the window (250) may be the same, and the tilting angle of the filter (240) and the tilting angle of the window (250) may be different. Alternatively, the tilting direction of the filter (240) and the tilting direction of the window (250) may be different, and the tilting angle of the filter (240) and the tilting angle of the window (250) may be the same. For example, the filter (240) may rotate 2 degrees clockwise about the first direction of the image sensor (210) and the window (250) may rotate 2 degrees counterclockwise about the first direction of the image sensor (210). Alternatively, the filter (240) may rotate 2 degrees counterclockwise about the first direction of the image sensor (210) and the window (250) may rotate 2 degrees clockwise about the first direction of the image sensor (210). Alternatively, the tilting direction of the filter (240) and the tilting direction of the window (250) may be different, and the tilting angle of the filter (240) and the tilting angle of the window (250) may be different.

[0130] In this way, when the filter (240) and the window (250) are tilted and arranged based on the rotation axis, ghost images can be avoided in the effective area (220A1) of the micro lens array (220), and the accuracy of object recognition can be increased.

[0131] Figure 9 is an optical path layout for simulating the cause of ghost occurrence, and Figure 10 is a result of simulating the cause of ghost occurrence.

[0132] Referring to FIGS. 9 and 10, ghost #1 is a ghost that occurs when double reflection occurs between the lens L2, which is positioned closer to the image sensor (210) among the two lenses included in the first lens unit (230), and the window (250), ghost #2 is a ghost that occurs when double reflection occurs between the lens L2, which is positioned closer to the image sensor (210) among the two lenses included in the first lens unit (230), and the filter (240), ghost #3 is a ghost that occurs when double reflection occurs between the sensor window on the image sensor (210) side and the window (250), ghost #4 is a ghost that occurs when double reflection occurs between the sensor window on the image sensor (240) side and the filter (240), and ghost #5 is a ghost that occurs when double reflection occurs between the sensor window on the image sensor (210) side and the lens L2, which is positioned closer to the image sensor (210) among the two lenses included in the first lens unit (230). A ghost that occurs when a reflection is triggered.

[0133] As ghost #3 and ghost #4 are most clearly shown in FIG. 10, it can be seen that the cause of ghosts that has the greatest influence in the one-dimensional sensor array structure according to the embodiment of the present invention is double reflection by the filter (240) and the window (250).

[0134] Figure 11 shows the simulation results according to the tilt of the window and filter.

[0135] Referring to FIG. 11, in an example where neither the filter nor the window is tilted, that is, in an example where the filter (240) is tilted 0 degrees relative to the first axis parallel to the first direction, which is the long axis of the image sensor (210), and the window (250) is tilted 0 degrees, it can be seen that a ghost image clearly exists on the effective area of ​​the one-dimensional sensor array structure. Next, in an example where only the filter among the filter and the window is tilted, that is, in an example where the filter (240) is tilted 2 degrees clockwise relative to the first axis parallel to the first direction, which is the long axis of the image sensor (210), and the window (250) is tilted 0 degrees, it can be seen that one ghost image is avoided outside the effective area of ​​the one-dimensional sensor array structure, but another ghost image still remains in the effective area. Next, in an example where only the window among the filter and the window is tilted, that is, in an example where the window (250) is tilted 2 degrees counterclockwise with respect to the first axis parallel to the first direction, which is the long axis of the image sensor (210), and the filter (240) is tilted 0 degrees, it can be seen that one ghost image is avoided outside the effective area of ​​the one-dimensional sensor array structure, but the other ghost image still remains in the effective area. In contrast, in an example where both the filter and the window are tilted, that is, in an example where the filter (240) is tilted 2 degrees clockwise with respect to the first axis parallel to the first direction, which is the long axis of the image sensor (210), and the window (250) is tilted 2 degrees counterclockwise, it can be seen that the ghost image is formed to deviate from the effective area of ​​the one-dimensional sensor array structure.

[0136] More specifically, FIG. 12 shows the results of performing ghost analysis for each angle of an object in a case where neither the window nor the filter is tilted with respect to the first axis parallel to the first direction, which is the long axis of the image sensor (210), and in a case where the window is not tilted and only the filter is tilted by 2 degrees. Referring to FIG. 12, it can be seen that the ghost phenomenon is alleviated at all angles of the object when the filter is tilted by 2 degrees compared to the case where neither the window nor the filter is tilted.

[0137] Next, Fig. 13 shows the results of performing ghost analysis for each angle of an object while tilting the window within a range of -2 degrees to 2 degrees with the filter tilted 2 degrees based on the first axis parallel to the first direction, which is the long axis of the image sensor (210). Referring to Fig. 13, it can be seen that when the window is also tilted while the filter is tilted, the ghost image is formed so as to deviate from the effective area of ​​the one-dimensional sensor array structure. In particular, it can be seen that when the window is tilted 2 degrees rather than 1 degree, the ghost image is formed at a further distance from the effective area of ​​the one-dimensional sensor array structure.

[0138] The light emitting unit (100) according to the present embodiment includes a light source unit (110) and a second lens unit (120). For detailed descriptions of the light source unit (110) and the second lens unit (120), reference may be made to FIGS. 14 to 19.

[0139] Specifically, FIG. 14 is a drawing for explaining a light emitting unit according to an embodiment of the present invention, FIG. 15 is a drawing for explaining a first lens surface of a lidar device according to an embodiment of the present invention, FIG. 16 is a drawing for explaining a second lens surface of a lidar device according to an embodiment of the present invention, FIG. 17 is a drawing for explaining a first unit pattern of a lidar device according to an embodiment of the present invention, FIG. 18 is a drawing for explaining a second unit pattern of a lidar device according to an embodiment of the present invention, and FIG. 19 is a drawing for explaining a relationship between a light source and a first lens surface of a lidar device according to an embodiment of the present invention.

[0140] First, referring to FIGS. 14 to 19, as shown in FIG. 14, a lidar device according to an embodiment of the present invention may include a light source unit (110), a second lens unit (120), and a volume Bragg grating (V) arranged side by side in a third direction.

[0141] Here, the volume Bragg grating (V) is illustrated to explain the optical path according to an embodiment of the present invention to be described later, and the volume Bragg grating (V) is only arranged to explain another embodiment of the present invention and the movement of the optical path according to an embodiment of the present invention, and is not limited to the arrangement of the volume Bragg grating (V) as mentioned.

[0142] First, the light source unit (110) irradiates light toward the second lens unit (120), and may be a collection of multiple light sources (111) irradiating light. Here, the light sources (111) may be long in the third direction and a plurality of light sources may be arranged in the first direction. In addition, the light sources (111) may be diodes that irradiate light from the side, i.e., from the end in the third direction, but may not necessarily be limited thereto.

[0143] That is, the lidar device according to the embodiment of the present invention may include a first lens surface (121) arranged to face the light source unit (110) and a second lens surface (126) arranged to be spaced apart from the first lens surface (121) and to face the first lens surface (121), the first lens surface (121) may include a plurality of first unit patterns (122) arranged in a first direction perpendicular to a third direction, the first unit patterns (122) extending along a second direction perpendicular to the first direction, and the second lens surface (126) may include a second lens unit (120) including a second unit pattern (127) extending along the first direction.

[0144] At this time, the third direction may refer to a direction in which the light source unit (110) views the second lens unit (120), the first direction may refer to a direction that is perpendicular to the third direction and in which the first unit pattern (122) is arranged, and the second direction may refer to a direction that is perpendicular to the first direction and the third direction and in which the first unit pattern (122) extends.

[0145] In addition, the length of the light source unit (110) in the first direction can be arranged to be relatively shorter than the length of the first lens surface (121) in the first direction, and light loss due to errors occurring during the manufacturing process or a spread angle occurring in the light source unit (110) can be prevented, and may not necessarily be limited to what has been mentioned.

[0146] Meanwhile, as shown in FIGS. 15 and 16, the first lens surface (121) and the second lens surface (126) have an asymmetrical shape and may be an aspherical shape.

[0147] This may be because the direction in which the light path incident on the first lens surface (121) is focused as parallel light and the direction in which the light path passes through the second lens surface (126) and is focused as parallel light are different.

[0148] To put it simply, in the first lens surface (121) according to the embodiment of the present invention, light irradiated from the light source (110) is incident and the light is focused in the first direction, and in the second lens surface (126), the light emitted can be focused onto the second lens surface (126).

[0149] That is, light irradiated from the light source (110) while passing through the first lens surface (121) and the second lens surface (126) can emit parallel light that is parallel to each other in the first direction and the second direction in the third direction.

[0150] At this time, as described above, a plurality of first unit patterns (122) may be arranged in the first direction to form a first lens surface (121), and a single second unit pattern (127) may be extended along the first direction to form a second lens surface (126).

[0151] Additionally, a plurality of first unit patterns (122) can extend along the second direction.

[0152] This arrangement may reflect the special characteristics of the first lens surface (121) that focuses light in the first direction and the special characteristics of the second lens surface (126) that focuses light in the second direction.

[0153] For example, due to the nature of light passing through a convex pattern, the light path changes depending on the refractive index as it passes through the convex surface, and in the case of the first lens surface (121), since the light must be focused in the first direction, it can be focused through a plurality of first unit patterns (122), and this can prevent loss of light due to the light spread angle due to the nature of the light source unit (110) that irradiates the light.

[0154] Meanwhile, in the detailed description of the present invention, it was mentioned that each of the first unit pattern (122) and the second unit pattern (127) according to the present invention has an aspherical shape, but this is mentioned as an aspherical shape based on the case where the first unit pattern (122) is judged as an individual lens, and the first lens surface (121) formed by a set of first unit patterns (122) may correspond to a surface having a plurality of curves formed by a set of first unit patterns (122) having an aspherical shape.

[0155] That is, the fact that the first lens surface (121) is an aspherical shape means that it has a lens shape other than a spherical shape, and it may not mean that the first lens surface (121) is an aspherical shape formed in a shape with a single curve.

[0156] In the drawings and detailed descriptions to be described later, as described above, the first lens surface (121) is referred to as an aspherical shape because it is a set of the first unit pattern (122), which is an aspherical shape when judged as an individual lens, and the second lens surface (126) is an aspherical shape because it is an extension of the second unit pattern (127). The fact that the first lens surface (121) and the second lens surface (126) are aspherical shapes may mean that each of them does not take the shape of a sphere or a part of a sphere based on the overall shape.

[0157] Meanwhile, as illustrated in FIG. 17, a plurality of first unit patterns (122) may be arranged along the first direction on the first lens surface (121).

[0158] In addition, the first unit pattern (122) can be arranged to have an arc shape based on an axis parallel to the second direction.

[0159] More specifically, the first unit pattern (122) has an arc shape having a first distance (R1) to the third axis (123) when defining a third axis (123) parallel to the second direction with respect to the second lens portion (120), and the first unit pattern (122) may have a recessed portion (124) arranged between adjacent first unit patterns (122).

[0160] At this time, the first distance (R1) does not form a part of a circle based on the third axis (123), but rather shows a part of an axis that serves as a reference for an arc shape formed by the first unit pattern (122), and the third axis (123) is any one of a number of reference axes on which the first unit pattern (123) is formed, but a set of reference axes forming the first unit pattern (122) may be arranged in a third direction together with the third axis (123).

[0161] Here, the distance between adjacent recessed portions (124) and recessed portions (124) is arranged to be the same, and the outermost point of the first unit pattern (122) in the third direction, more specifically, the outermost point in the direction looking at the light source portion (110), is defined as the first unit pattern (122a), and the distance between adjacent first unit patterns (122a) can be the same.

[0162] In other words, the first unit pattern (122a) may be the radially outermost point of the first unit pattern (122) in the third direction.

[0163] That is, the first unit pattern (122) has an arc shape with a first distance (R1) based on the third axis (123), and the first unit pattern (122a) facing the light source (110) in the third direction is arranged, the distance between the first unit patterns (122a) is the same, and the distance between the recessed portions (124) arranged between the first unit patterns (122) can also be the same.

[0164] Through this, the light irradiated from the light source (111) can be made to have uniform parallel light.

[0165] Additionally, the first unit pattern (122) may be in the form of a column in which the distance between the third axis (123) and the first unit pattern (122a) is the same in the second direction.

[0166] That is, the distance between the third axis (123) and the first unit pattern (122a) in the second direction may be equal to the first distance (R1).

[0167] Meanwhile, as illustrated in FIG. 18, the second unit pattern (127) of the second lens surface (126) can be arranged to have an arc shape based on an axis parallel to the first direction, similar to the first lens surface (121).

[0168] More specifically, when defining a fourth axis (128) parallel to the first direction with respect to the second lens unit (120), it may have an arc shape having a second distance (R2) to the fourth axis (128).

[0169] Here, the second unit pattern (127) is formed with an outermost point that is relatively far from the light source (110) in the third direction, and when the outermost point of the second unit pattern (127) is defined as the second outermost point (127a), the distance between the fourth axis (128) and the second outermost point (127a) may be the second distance (R2).

[0170] Through this, light passing through the first lens surface (121) can be made to have uniform parallel light in the first and second directions.

[0171] In other words, the second outermost point (127a) may be the radially outermost point of the second unit pattern (127) in the third direction.

[0172] Here, the second unit pattern (127) may be in the form of a semi-cylindrical shape in which the distance between the fourth axis (128) and the second outermost point (127a) is the same in the first direction.

[0173] That is, the distance between the fourth axis (128) and the second outermost point (127a) in the first direction of the second unit pattern (127) may be equal to the second distance (R2).

[0174] To summarize, the first lens surface (121) is arranged to have multiple convex surfaces in the first direction since a plurality of first unit patterns (122) are arranged in the first direction, and the second lens surface (126) is arranged to have a single convex surface in the second direction since a single second unit pattern (127) extends along the first direction.

[0175] At this time, the second distance (R2) does not form a part of a circle based on the fourth axis (128), but rather shows a part of an axis that serves as a reference for an arc shape formed by the second unit pattern (127), and the fourth axis (128) is any one of a number of reference axes on which the second unit pattern (127) is formed, but the set of reference axes forming the second unit pattern (127) may be arranged in the third direction together with the fourth axis (128).

[0176] Here, the third axis (123) forming the first unit pattern (122) and the fourth axis (128) forming the second unit pattern (127) can be arranged perpendicular to each other.

[0177] More specifically, since the first lens surface (121) focuses light in the first direction and the second lens surface (126) focuses light in the second direction, the curvatures of the first lens surface (121) and the second lens surface (126) must be formed asymmetrically with respect to each other, and in order for each surface to focus light in a single direction, it may be preferable for it to take an aspherical shape, such as the first lens surface (121) and the second lens surface (126) according to the embodiment of the present invention.

[0178] That is, the first lens surface (121) that focuses light in the first direction may have a form in which a plurality of light sources (111) are arranged in the first direction, and thus the first lens surface (121) may have a form in which a plurality of first unit patterns (122) are arranged in the first direction.

[0179] In addition, based on the second direction, the light source (111) can be defined as being irradiated from a single point, and thus, unlike the first lens surface (121), the second lens surface (126) can be formed as a single second unit pattern (127).

[0180] Here, the light source (111) in the second direction has a single arrangement shape, and the second lens surface (126) is formed as a single second unit pattern (127), so that uniform parallel light can be output as a single second unit pattern (127).

[0181] At this time, when distinguishing between the second lens surface (126) and the second unit pattern (127), the second lens surface (126) may mean the surface of a semi-cylindrical shape formed by the second unit pattern (127), and the second unit pattern (127) may mean a pattern forming a semi-cylindrical shape.

[0182] That is, the second lens surface (126) refers to the surface itself, and the second unit pattern (127) refers to the pattern itself forming the second lens surface (126). This is the same in the content described below, and the second unit pattern (127) and the second lens surface (126) can have the same meaning in cross-sectional shape.

[0183] However, the first lens surface (121) is a surface formed by a set of a plurality of first unit patterns (122), and the first lens surface (121) may mean the surface itself formed by the plurality of first unit patterns (122), and the first unit pattern (122) may mean a pattern in the form of a cross-section of the second lens portion (120) cut in the first direction when viewed from the second direction.

[0184] That is, when the cross-sectional shape of the second lens unit (120) is viewed from the second direction, a set of a plurality of first unit patterns (122) forms the first lens surface (121), and when the cross-sectional shape of the second lens unit (120) is viewed from the first direction, the shape of the first unit pattern (122) varies depending on the cut cross-sectional shape, so the cross-sectional shape of the second lens unit (120) viewed from the first direction can be referred to as the first lens surface (121).

[0185] Meanwhile, based on the suggestion, as shown in Fig. 19, a plurality of light sources (111) are provided in the light source unit (110), and the plurality of light sources (111) can irradiate light from the side.

[0186] Specifically, light can be irradiated from a light source (111) toward the first lens surface (121), and the light source (111) can be arranged to overlap with the first unit pattern (122) in the third direction.

[0187] More specifically, the third axis (123) forming the first unit pattern (122) and the light source (111) overlap in the third direction, and the light source (111), the first unit pattern (122a), and the third axis (123) can be arranged side by side so as to overlap in the third direction.

[0188] That is, the recessed portion (124) and the light source (111) in the third direction do not overlap each other, and can be positioned similarly to the recessed portion (124) being positioned between the light sources (111) in the first direction.

[0189] As a result, light spread based on the light source (111) can pass through the first lens surface (121) and be emitted as uniform parallel light based on the first direction.

[0190] For a more detailed explanation based on the arrangement and configuration described above, reference may be made to FIGS. 20 to 25.

[0191] Specifically, FIG. 20 is a diagram illustrating a first unit pattern and a light emitting unit of a lidar device according to an embodiment of the present invention, FIG. 21 is a diagram illustrating an optical path through a first lens surface of a lidar device according to an embodiment of the present invention, FIG. 22 is a diagram illustrating an optical path through a second lens surface of a lidar device according to an embodiment of the present invention, FIG. 23 is a diagram illustrating a focus of a lidar device according to an embodiment of the present invention, FIG. 24 is a diagram illustrating an optical path traveling and a reflected optical path through a first lens surface of a lidar device according to an embodiment of the present invention, and FIG. 25 is a diagram illustrating an optical path traveling and a reflected optical path through a second lens surface of a lidar device according to an embodiment of the present invention.

[0192] First, as illustrated in FIG. 20, a plurality of light sources (111) are arranged in the first direction, a plurality of first unit patterns (122) are arranged in the first direction, and the first unit patterns (122) and the light sources (111) can overlap each other in the third direction.

[0193] In addition, the light source (111) irradiates light to the side, and a space that is sunken in the second direction can be arranged between the light sources (111).

[0194] Due to this, the light source unit (110) and the first lens surface (121) can be arranged so that the first unit pattern (122) and the light source (111) overlap each other, and the sunken space of the sunken unit (124) and the light source unit (110) overlap each other.

[0195] Here, the first lens surface (121) collects light in the first direction as described above, and as shown in FIG. 21, light irradiated from the light source (111) can be incident on the first lens surface (121) with a spread angle in the first direction.

[0196] At this time, light incident on the first lens surface (121) can be focused in the first direction by a plurality of first unit patterns (122), and in the process of moving from the first lens surface (121) to the second lens surface (126), a set of optical paths can be formed in which light is focused in the first direction and not focused in the second direction.

[0197] Meanwhile, light irradiated from the light source (110) can be focused in the second direction while passing through the first lens surface (121) and the second lens surface (126) at a spreading angle in the second direction.

[0198] That is, a set of optical paths that pass through the first lens surface (121) and the second lens surface (126) and are focused in the first and second directions can be formed, and light irradiated from the light source unit (110) can be irradiated as parallel light through the second lens unit (120).

[0199] When examining parallel light in this way, efficiency can be increased by preventing light from being lost to the outside of a separate lens that adjusts the viewing angle.

[0200] Meanwhile, to explain the present invention in more detail, in the present invention, a light source (111), a second lens unit (120), and a volume Bragg grating (V) can be arranged in a third direction similar to FIG. 1.

[0201] At this time, the focus (F) of the second lens unit (120) according to the embodiment of the present invention is formed based on the light source (111) that irradiates light, and the characteristics of the first lens surface (121) and the second lens surface (126) may be as follows.

[0202] Item 1 Lens surface (121) 2nd lens surface (126) Material n (refractive index) = 1.89406@1430nm Thickness (mm) 4.7 Light source (111) Divergence angle (2*NA) (deg) 25.577.9 Numerical aperture (1 / (2*FNO) 0.220.63 F number (F Number) 2.270.80 Effective focal length (EFL) (mm) 0.5383.002 Back focal length (BFL) (mm) 0.5410.541 Radius (mm) 0.4810-2.7018 Conic constant -3.5874-0.7648

[0203] First, the divergence angle of the light irradiated from the light source (111) can be 25.5 degrees on the first lens surface (121) and 77.9 degrees on the second lens surface (126).

[0204] To put it more concretely, light irradiated from a light source (111) is diverged at 25.5 degrees in a first direction where the first lens surface (121) collects light, diverged at 77.9 degrees in a second direction where the second lens surface (126) collects light, and light incident at 25.5 degrees by a plurality of first unit patterns (122) arranged on the first lens surface (121) is collected in the first direction and output as parallel light, and light passing through the second lens surface (126) in the second direction is collected in the second direction and output as parallel light.

[0205] In addition, since the light passing through the first lens surface (121) and the second lens surface (126) according to the embodiment of the present invention has a divergence angle of 25.5 degrees in the first direction and 77.9 degrees in the second direction as described above, the refractive index of the second lens unit (120) may be 1.89406 so that the light passing through the second lens unit (120) is output as parallel light.

[0206] Through this, the second lens unit (120) according to the embodiment of the present invention can output the light irradiated from the light source (111) as parallel light by focusing it in the first direction and the second direction, thereby preventing the loss of light that escapes from the second lens unit (120).

[0207] That is, when looking at the refractive index of the second lens unit (120), it may be desirable to have a refractive index within 1.8 to 2.0.

[0208] In addition, the divergence angle of the designed light source (111) can be calculated using [Mathematical Formula 1] presented below for the design aperture value (Numerical Aperture (hereinafter referred to as design NA)) described later.

[0209] [Mathematical Formula 1]

[0210] [Design light source (111) divergence angle] = 2*n*sin(design NA)

[0211] This allows the light output as parallel light to be reflected off the object without loss by controlling the angular range at the aperture over which the design NA can accept or emit light, thereby achieving higher resolution through the light.

[0212] Here, the design NA can be explained through [Mathematical Formula 2] and [Mathematical Formula 3] described later.

[0213] [Equation 2]

[0214] [Design NA] = 1 / (2*F Number)

[0215] [Equation 3]

[0216] [F Number] = Focus (F) / Diameter (D)

[0217] As presented, the design NA is designed to be inversely proportional to the F Number (hereinafter referred to as the F number), and since the F number is inversely proportional to the diameter of the incident lens surface, the F number of the first lens surface (121) relatively adjacent to the light source (111) may be relatively larger than the F number of the second lens surface (126).

[0218] This may be a desirable design form for obtaining higher resolution by preventing loss of light in the process of light irradiated from a light source (111) being irradiated toward an object or reflected from an object and incident thereon, as described above, and may not necessarily be limited to what has been mentioned.

[0219] Meanwhile, when the F number of the first lens surface (121) of the second lens unit (120) is defined as FNO-1 and the F number of the second lens surface (126) is defined as FNO-2, FNO-1 and FNO-2 may fall within the ranges shown in [Mathematical Formula 4] below.

[0220] [Equation 4]

[0221] 0.2 < FNO-2 / FNO-1 < 0.5

[0222] That is, according to [Mathematical Formula 4], the F number of the second lens surface (126) may be 0.2 to 0.5 times greater than the F number of the first lens surface (121).

[0223] This corresponds to a desirable form according to the arrangement of the light source (111) in the first direction, the form in which a plurality of first unit patterns (122) are arranged in the first direction, and the difference in the diameter of the first lens surface (121) in the first direction and the diameter of the second lens surface (126) in the second direction, thereby enabling uniform parallel light to be output.

[0224] Meanwhile, when the effective focal length of the first lens surface (121) of the second lens unit (120) is defined as EFL-1 and the effective focal length of the second lens surface (126) is defined as EFL-2, EFL-1 and EFL-2 may fall within the ranges shown in [Mathematical Formula 5] below.

[0225] [Equation 5]

[0226] 4 < EFL-2 / EFL-1 < 8

[0227] That is, according to [Mathematical Formula 5], the effective focal length of the second lens surface (126) may be 4 to 8 times greater than the effective focal length of the first lens surface (121).

[0228] This corresponds to the value when the first lens surface (121) and the second lens surface (126) are used as references, respectively, and due to the difference in the effective focal length according to the difference in the arc shape of the first lens surface (121) and the second lens surface (126), the optical path of light is output as parallel light, and by outputting uniform parallel light, a high resolution can be output without any light loss.

[0229] Meanwhile, the back focal length (BFL) of the first lens surface (121) corresponds to the distance from the focus (F) based on the first unit pattern (122a), and in the case of the second lens surface (126), since there is no rearmost lens for determining the back focal length (BFL), the first unit pattern (122a) of the first lens surface (121) can be used as a reference.

[0230] That is, the rear focal length of the first lens surface (121) and the rear focal length (BFL) of the second lens surface (126) may ultimately be equal to the distance between the rear (B) and the focus (F) of the second lens unit (120).

[0231] However, if we look at this in an extended way, the back focal length (BFL) corresponds to the distance between the light source (111) and the second lens unit (120) although the first lens surface (121) and the second lens surface (126) are the same, so it may be desirable for the distance between the back focal lengths (BFL) to be within 0.3 to 1.0.

[0232] By designing the back focal length (BFL) within the given range, it is possible to prevent the problem of light being lost at the first lens surface (121) due to the spread angle of light irradiated from the light source (111), output parallel light without loss of light, and output high resolution.

[0233] Meanwhile, the first distance (R1) of the first lens surface (121) of the second lens unit (120) according to the embodiment of the present invention may correspond to the distance between the third axis (123) forming the first unit pattern (122) and the first outermost point (122a) as described above, and when the direction of light propagation in the third direction centered on the second lens unit (120) is assumed to be negative and the direction toward the light source (111) is assumed to be positive, the first distance (R1) may be 0.4810.

[0234] In addition, the second distance (R2) of the second lens surface (126) of the second lens unit (120) may correspond to the distance between the fourth axis (128) forming the second unit pattern (127) and the first outermost point (127a) as described above, and when the direction of light propagation in the third direction centered on the second lens unit (120) is assumed to be negative and the direction toward the light source (111) is assumed to be positive, the second distance (R2) may be -2.7018.

[0235] This may be due to the difference in size between the first unit pattern (122) corresponding to a relatively small unit pattern and the second unit pattern (126) having a unit pattern relatively larger than the first unit pattern (122), and this may be due to the fact that the divergence angle of the light in the first direction incident on the first lens surface (121) described above and the divergence angle of the light in the second direction passing through the second lens surface (126) are different from each other.

[0236] The first distance (R1) and the second distance (R2) described above correspond to the basic conditions for designing the first unit pattern (122) and the second unit pattern (126) to have an arc shape in order to focus light in the first direction and the second direction, and thus, the first lens surface (121) formed by the set of the first unit patterns (122) and the second lens surface (126) formed by the extension of the second unit patterns (126) focus light in the first direction and the second direction, respectively, to output parallel light, thereby preventing light from being lost due to the focus of the light, and outputting high resolution.

[0237] In addition, the conic constant of the first lens surface (121) is -3.5874, and the conic constant of the second lens surface (126) is -0.7648, which can be confirmed through [Table 2] below.

[0238] Surface Aspheric 4th Aspheric 6th Aspheric 8th Aspheric 10th Aspheric 12th Aspheric 2nd Lens Surface (126) -2.4250E-03-1.0307E-04 1.5461E-06-5.8078E-07 2.0685E-07

[0239] As presented, since the first lens surface (121) is a set of a plurality of first unit patterns (122), when only the aspherical coefficient for the second lens surface (126) is examined, it is desirable to apply an aspherical coefficient with a conic constant of -0.7648 when applying the aspherical coefficient of the second lens surface (126), and it may be desirable to apply a conic constant of -3.5874 to the first lens surface (121) corresponding to the second lens surface (126).

[0240] Through this, as described above, the first lens surface (121) and the second lens surface (126) are each formed as an aspherical surface, and parallel light can be output in the first direction in which the first lens surface (121) focuses light and in the second direction in which the second lens surface (126) focuses light, respectively.

[0241] As a result, parallel light collected in the first and second directions can be output and reflected on an object without any light loss, and the reflected light can be incident and have the advantage of outputting high resolution.

[0242] Meanwhile, when a reflection-type volume Bragg grating (V) is arranged in a lidar device according to an embodiment of the present invention, light irradiated from a light source (111) passes through the second lens unit (120) and is output as parallel light, and can be irradiated toward the reflection-type volume Bragg grating (V).

[0243] However, the volume Bragg grating (V) allows some light to pass through and some light to be reflected, and the reflected light can travel along the same optical path to the light source (111).

[0244] That is, if this situation is repeated, a light resonance structure can be formed between the light source (111) and the volume Bragg grating (V).

[0245] Specifically, as illustrated in FIG. 24, light irradiated from a light source (111) is focused in a first direction by a first lens surface (121) and moves toward a volume Bragg grating (V) as parallel light, some of the light is reflected from the volume Bragg grating (V), and the reflected light can move along the same optical path toward the light source (111).

[0246] In addition, as illustrated in FIG. 25, light irradiated from a light source (111) is focused in the second direction by a second lens surface (126) and moves toward a volume Bragg grating (V) as parallel light, some of the light is reflected from the volume Bragg grating (V), and the reflected light can move along the same optical path toward the light source (111).

[0247] As a result, the present invention includes a first unit pattern (122) in the shape of an arc having a first distance (R1) based on a third axis (123), and a plurality of first unit patterns (122) are arranged in a first direction to form a first lens surface (121).

[0248] In addition, the second lens surface (126) includes a second unit pattern (127) in the shape of an arc having a second distance (R2) based on the fourth axis (128), and the second unit pattern (127) can extend along the first direction to form the second lens surface (126).

[0249] In addition, the third axis (123) that serves as the reference for the first unit pattern (122) and the fourth axis (128) that serves as the reference for the second unit pattern (127) are perpendicular to each other, and the direction in which the first unit pattern (122) extends and the direction in which the second unit pattern (127) extends can also be perpendicular to each other.

[0250] Meanwhile, it is preferable that the lidar device (1000) according to the embodiment of the present invention be applied to a wavelength band of 1350 nm to 1450 nm as previously presented in [Table 1], that is, the light irradiated from the light source (111) may be in a wavelength band of 1350 nm to 1450 nm.

[0251] More specifically, the wavelength band of light irradiated from the light source (111) may preferably be 1400 nm to 1430 nm, and 1430 nm based on [Table 1].

[0252] As a result, 1430 nm is a wavelength band corresponding to 1.43 μm, which is generally a wavelength band corresponding to near-infrared rays, and since the lidar device (1000) senses 3D image information of an object (subject) by detecting light reflected from an object (subject) at a mid- to long-distance, it may be desirable to apply near-infrared rays suitable for mid- to long-distance.

[0253] That is, the lidar device (1000) according to the embodiment of the present invention preferably utilizes a light source (111) that irradiates light in a wavelength band of 1350 nm to 1450 nm to enhance the effect of image sensing, and specifically, it is a light source (111) that irradiates light in a wavelength band of 1430 nm, and the second lens unit (120) according to the embodiment of the present invention can collect light in a wavelength band of 1430 nm and output it as parallel light to enhance the resolution of 3D image information of the lidar device (1000).

[0254] FIG. 26 is a perspective view of a lidar system according to an embodiment of the present invention, FIG. 27 is an exploded view of a lidar system according to an embodiment of the present invention, and FIG. 28 is an exploded view of a lidar device according to an embodiment of the present invention.

[0255] Referring to FIGS. 26 to 28, the light emitting unit (100) and the light receiving unit (200) may be accommodated within the housing (50) of the lidar system (1200). As illustrated, one lidar system (1200) may include a plurality of lidar devices (1000). For example, each lidar device (1000) included within one lidar system (1200) may include a light emitting unit (100) and a light receiving unit (200), and the two lidar devices (1000) may be arranged to face opposite directions.

[0256] A plurality of openings may be formed in the housing (50). Among the plurality of openings, a first opening (51) may be arranged to correspond to a window (250) of a lidar device (1000) and may serve as a passage for light emission and light reception. Among the plurality of openings, a second opening (52) may serve as a passage for dissipating heat generated from a lidar device (1000) housed within the housing (50).

[0257] The number of first openings (51) may be less than the number of second openings (52), and the diameter of the first opening (51) may be greater than the diameter of the second opening (52). Since the first openings (51) are arranged to correspond to the windows (250) of the lidar device (1000), the number of first openings (51) formed in the housing (50) may be equal to the number of lidar devices (1000) accommodated in the housing (50).

[0258] Each lidar device (1000) includes a light emitting unit (100) and a light receiving unit (200), and for this purpose, each lidar device (1000) may further include a mount (600) on which the light emitting unit (100) and the light receiving unit (200) are mounted. The light emitting unit (100) is placed on the side of the light receiving unit (200), and both light emitted from the light emitting unit (100) and light reflected from an object and then incident on the light receiving unit (200) can pass through the window (250).

[0259] Although not specifically illustrated, the light emitting unit may include a substrate, a light source, an optical member, a shield member, and a diffusion member. The substrate may include a printed circuit board (PCB). The substrate may also be connected to a connector via an FPCB. The light source is disposed on the substrate, and the substrate may include a terminal. The light source may correspond to the light source of the light emitting unit (100) described above. That is, the light source may include a plurality of emitters arranged in an array shape. The plurality of emitters may be arranged in an m*n matrix so that the light receiving unit (200) may correspond to a pixel array of the image sensor (210), but is not limited thereto. The driving of the plurality of emitters may be individually controlled or integratedly controlled. The optical member may collect light emitted from the light source or convert an optical path of light emitted from the light source. For example, when the light source is not arranged to face the window (250), the optical member can change the optical path so that the light emitted from the light source is emitted through the window (250). The shield member surrounds the substrate and the light source, may be referred to as a cover can, may be non-magnetic, and thus may block electromagnetic interference (EMI). The diffusion member may be a diffuser lens or a homogenizer. The diffusion member may be arranged on the optical path of the light emitted from the light source.

[0260] The light receiving unit (200) may include a sensor unit and a lens unit. The sensor unit may include a substrate, an image sensor (210) disposed on the substrate, and a micro lens array disposed on the image sensor (210). The image sensor (210) may detect infrared rays. The image sensor (210) may detect light of a specific wavelength among infrared rays. The lens unit may include a lens barrel (260), a plurality of lenses, a filter, and a lens hood (270). The image sensor (210) may detect light passing through the filter. The image sensor (210) may detect light in the wavelength band of the light source. Through this, the image sensor (210) may detect light emitted from the light source and reflected on the subject, thereby sensing 3D image information of the subject.

[0261] As described above, the lidar device according to an embodiment of the present invention may be a mechanical lidar device. Accordingly, the lidar device according to an embodiment of the present invention may be designed to rotate 360 ​​degrees by a motor.

[0262] Having described preferred embodiments of the invention, it will be apparent to those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or scope thereof, in addition to the embodiments described above.

[0263] Therefore, the above-described embodiments should be considered as illustrative rather than restrictive, and accordingly, the present invention is not limited to the above description but may be modified within the scope of the appended claims and their equivalents.

Claims

1. A light emitting unit that irradiates a light signal to an object, and Includes a light receiving unit that receives a light signal reflected from the object, The above light receiving unit, An image sensor comprising a light-receiving surface having a long axis in a first direction, A first lens unit disposed on the image sensor; A window disposed on the first lens unit, and A filter disposed between the image sensor and the window, A lidar device in which at least one of the filter and the window is tilted relative to a virtual first axis parallel to the long axis of the light-receiving surface of the image sensor or a second axis inclined with respect to the first axis.

2. In paragraph 1, The image sensor includes a pixel array arranged along the first direction and a second direction perpendicular to the first direction, and the number of pixels arranged along the first direction is greater than the number of pixels arranged along the second direction. A lidar device in which at least one of the filter and the window is tilted about the first direction as a rotation axis.

3. In paragraph 2, The above filter and the above window are each a tilted lidar device with the first direction as the rotation axis.

4. In paragraph 1, A micro lens array is disposed between the image sensor and the first lens unit and has a long axis in the first direction, A lidar device wherein at least one of the filter and the window is tilted about an imaginary axis parallel to the long axis of the micro lens array with respect to the micro lens array.

5. In paragraph 4, The micro lens array includes a plurality of micro lenses arranged along the first direction and a second direction perpendicular to the first direction, A lidar device in which the number of micro lenses arranged along the first direction is greater than the number of micro lenses arranged along the second direction.

6. In paragraph 1, A lidar device wherein the image sensor includes an m*n pixel array, and a ratio of m to n is 8 or greater.

7. In paragraph 3, A lidar device wherein one of the filter and the window is tilted clockwise with the first direction as the rotation axis, and the other of the filter and the window is tilted counterclockwise with the first direction as the rotation axis.

8. In paragraph 1, The above light emitting part is, light source; and A second lens unit including a first lens surface facing the light source unit and a second lens surface arranged in an opposite direction to the first lens surface, The first lens surface includes a plurality of first unit patterns arranged in the first direction, and the first unit patterns extend along a second direction perpendicular to the first direction. A lidar device wherein the second lens surface includes a second unit pattern having a long axis extending along the first direction.

9. In paragraph 8, A lidar device in which the first lens surface and the second lens surface are asymmetrical to each other.

10. In paragraph 9, The above first unit pattern has an arc shape based on an axis parallel to the second direction, The above second unit pattern is a lidar device having an arc shape based on an axis parallel to the first direction.

Images