Multi-lens structure and optical scanning device

Abstract

Provided are a multi-lens structure and an optical scanning device including same. The multi-lens structure comprises: a condensing lens; and a 2D conversion lens array structure that vertically disperses light passing through the condensing lens. The optical scanning device comprises: a light source; a horizontal splitting device for generating horizontally split light from light emitted from the light source; the multi-lens structure that transmits the horizontally split light and irradiates the light to an object; and a detector for detecting the light irradiated from the multi-lens structure and reflected from the object.

Description

Multi-lens structure and optical scanning device

[0001] The present invention relates to a multi-lens structure and an optical scanning device. More specifically, the present invention relates to a multi-lens structure including a plurality of lens structures and an optical scanning device utilizing the same.

[0002]

[0003] For example, LiDAR (Light Detection And Ranging) sensors are radar systems that measure the positional coordinates of a reflector by measuring the time it takes for laser light to be reflected and returned. LiDAR sensors are used in a variety of devices, including automobiles, robots, and drones. Recently, LiDAR sensors have been installed on aircraft and satellites for topographic surveying, and are also being utilized in speed guns, autonomous mobile robots, and self-driving cars.

[0004] LiDAR sensors can generate information about objects based on the time-of-flight (ToF) measurement of light. For example, a LiDAR sensor transmits light toward an object and receives it back through the sensor, measuring the time-of-flight using high-speed electrical circuits. The LiDAR sensor then calculates the distance to the object from the time-of-flight and, using the calculated distance for each position of the object, generates additional information about the object.

[0005] However, when measuring using the ToF method, information on speed is not produced in real time, and if the emitted laser pulse is weakened by an atmospheric environment such as fog, the measurement intensity and measurement sensitivity may decrease.

[0006] For optical scanning, the transmitted light can be split into phased arrays. However, even with the phased array splitting, sufficiently high-precision position / velocity information may not be generated.

[0007]

[0008] One object of the present invention is to provide a multi-lens structure having improved precision and reliability.

[0009] An object of the present invention is to provide an optical scanning device having improved precision and reliability.

[0010]

[0011] 1. A multi-lens structure comprising a condenser lens; and a 2D transformation lens array structure that disperses light passing through the condenser lens in a vertical direction.

[0012] 2. In the above 1, the condenser lens is a multi-lens structure including a multilayer lens including an F-theta lens.

[0013] 3. A multi-lens structure further comprising a wide-angle lens disposed between the multilayer lens and the 2D transformation lens array structure in the above 2.

[0014] 4. In the above 3, the wide-angle lens is a multi-lens structure having two surfaces with different curvatures.

[0015] 5. A multi-lens structure in which, among the surfaces of the wide-angle lens in the above 4, the curvature of the incident surface facing the multilayer lens is smaller than the curvature of the exit surface facing the 2D transformation lens array structure.

[0016] 6. In the above 1, the 2D transformation lens array structure,

[0017] A multi-lens structure comprising a lens substrate; and lenses arranged in a row direction on the lens substrate and having different refractive angles.

[0018] 7. In the above 6, the lenses form a multi-lens structure that distributes horizontally divided light into a plurality of columns.

[0019] 8. A multi-lens structure according to 6 above, wherein the lens substrate includes a first substrate and a second substrate, and the lenses include a micro lens array arranged on the first substrate and a micro prism array arranged on the second substrate.

[0020] 9. In the above 6, the lenses include composite lenses in which micro lenses and micro prism structures are integrated. A multi-lens structure.

[0021] 10. In the above 6, the lenses are a multi-lens structure including interference patterns including Fresnel lenses.

[0022] 11. In the above 6, the lenses included in the 2D transformation lens array structure are a multi-lens structure that correspond to the light spots generated through the condenser lens.

[0023] 12. An optical scanning device comprising: a light source; a horizontal splitting device that generates horizontally split lights from light emitted from the light source; a multi-lens structure according to the above-described embodiments that passes the horizontally split lights and irradiates the lights to an object; and a detector that detects lights reflected from the object by the lights irradiated from the multi-lens structure.

[0024] 13. In the above 12, the horizontal division device is an optical scanning device including an optical phased array (OPA) element.

[0025] 14. In the above 12, the spot area of ​​each of the horizontally divided lights is reduced by the focusing lens included in the multi-lens structure. An optical scanning device.

[0026] 15. In the above 14, the multi-lens structure further includes a wide-angle lens arranged between the condenser lens and the 2D conversion lens array structure,

[0027] An optical scanning device in which the wide angle between the horizontally divided lights collected by the collecting lens is increased through the wide-angle lens.

[0028] 16. An optical scanning device in which vertically split lights are generated by the 2D transformation lens array structure included in the multi-lens structure in the above 12.

[0029] 17. An optical scanning device according to the above 12, further comprising a second lens structure disposed between the multi-lens structure and the target object to perform positional correction.

[0030] 18. An optical scanning device according to 12 above, further comprising an amplifier disposed between the light source and the horizontal splitting device.

[0031]

[0032] A multi-lens structure according to embodiments of the present invention may include a multilayer lens, such as an F-theta lens, and a 2D transformation lens array structure. The multilayer lens may, for example, increase the angle of light to be horizontally split, while decreasing the size of the light spot. Accordingly, additional light spots can be inserted into a limited space while increasing the distance between adjacent light spots.

[0033] Therefore, the resolution and precision of a sensor device including the multi-lens structure can be improved.

[0034] The above 2D transformation lens array structure may include an array of multiple lenses, each having a different refractive angle. Light split in the horizontal direction through the multilayer lens may be distributed in the vertical direction, so that each wavelength of light may be assigned a position on a two-dimensional plane. Accordingly, the multi-lens structure may increase the signal processing speed while implementing continuous optical scanning through a sensor.

[0035] According to embodiments of the present invention, the multi-lens structure can be applied to an optical scanning device such as a lidar sensor. The optical scanning device can include the multi-lens structure as a horizontal light splitting device and a vertical light splitting device. Transmission light horizontally split by the horizontal light splitting device can be finely split again by the vertical light splitting device. Accordingly, the precision and resolution of measurement information of an object are improved, and velocity information of the object can be scanned and collected in real time. In addition, position / velocity information of an object can be detected with a single detector through optical scanning.

[0036] For example, mechanical beam splitting devices such as separate motors or rotors can be eliminated, thereby avoiding inaccuracies in beam scanning caused by vibration or shock of the mechanical beam splitting device. In addition, optical efficiency can be improved by employing a lens as a vertical beam splitting device.

[0037] In one embodiment, the lidar sensor may be provided as an FMCW type sensor, and may suppress the deterioration of precision due to external light / external environment (snow, rain, fog, etc.) and provide position sensing that is harmless to the human body (e.g., the naked eye).

[0038]

[0039] FIG. 1 is a schematic cross-sectional view showing a multi-lens structure according to exemplary embodiments.

[0040] FIG. 2 is a schematic cross-sectional view illustrating a multi-lens structure according to some exemplary embodiments.

[0041] FIG. 3 is a schematic cross-sectional view showing a 2D transformation lens array structure according to exemplary embodiments.

[0042] FIGS. 4 and 5 are schematic cross-sectional views illustrating a 2D transformation lens array structure according to some exemplary embodiments.

[0043] Figure 6 is a schematic drawing for explaining light splitting by a lens according to a comparative example.

[0044] FIG. 7 is a schematic diagram illustrating light splitting by a multi-lens structure according to exemplary embodiments.

[0045] FIG. 8 is a schematic block diagram illustrating an optical scanning device according to exemplary embodiments.

[0046] FIG. 9 is a schematic block diagram illustrating an optical scanning device according to exemplary embodiments.

[0047] FIG. 10 is a schematic perspective view showing a horizontal splitting device according to exemplary embodiments.

[0048] FIG. 11 is a cross-sectional view illustrating a second lens structure according to exemplary embodiments.

[0049]

[0050] Embodiments of the present invention provide a multi-lens structure including a plurality of lenses. Embodiments of the present invention provide an optical scanning device including a light source, a light splitting device, and a detector.

[0051] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in such drawings.

[0052] The terms “first,” “second,” “top,” “bottom,” “upper,” and “lower” used in this specification do not limit absolute positions or orders, but are used in a relative sense to distinguish different components or parts.

[0053] The term "row direction" as used in this application may refer to a horizontal direction, and the term "column direction" may refer to a vertical direction perpendicular to the row direction. A two-dimensional (2D) plane may be defined by the row direction and the column direction.

[0054] FIG. 1 is a schematic cross-sectional view showing a multi-lens structure according to exemplary embodiments.

[0055] Referring to FIG. 1, the multi-lens structure (50) may include a multilayer lens (60) and a 2D transformation lens array structure (80). The multilayer lens (60) may be provided as a condenser lens. According to exemplary embodiments, light may pass through the multilayer lens (60) and have an increased wide angle, and may be incident on the 2D transformation lens array structure (80).

[0056] According to exemplary embodiments, the light beams horizontally split by the horizontal splitting device described below may have an increased light angle as they pass through the multilayer lens (60). Accordingly, substantially horizontally split light beams may be generated. The horizontally split light beams may be vertically split or vertically shifted by the 2D transformation lens array structure (80), so that the one-dimensionally arranged light beams may be dispersed or distributed into a two-dimensional plane.

[0057] The structure of the 2D conversion lens array structure (80) will be described in more detail later with reference to FIGS. 3 to 5.

[0058] According to embodiments of the present invention, the multilayer lens (60) may include an F-theta lens. As the wide angle of the horizontally split light beams increases due to the F-theta lens, the individual light beams are focused, thereby reducing the area of ​​the individual light spots. Accordingly, the number of light beams that can be split in a limited area can be further increased.

[0059] According to exemplary embodiments, the multilayer lens (60) may include a plurality of lenses selected from a diffractive lens, a concave lens, a convex lens, a concave / convex composite lens, and the like.

[0060] The multilayer lens (60) may be provided as a collecting lens that reduces the diameter of light. The generation of light spots from split lights through the multilayer lens (60) will be described in more detail later with reference to FIGS. 6 and 7.

[0061] FIG. 2 is a schematic cross-sectional view illustrating a multi-lens structure according to some exemplary embodiments.

[0062] Referring to FIG. 2, the multi-lens structure (50) may further include a wide-angle lens (70) positioned between the multilayer lens (60) and the 2D transformation lens array structure (80).

[0063] The angle between adjacent split beams can be further increased through the wide-angle lens (70). Accordingly, the resolution between beams can be further increased, and a wider wide-angle can be provided using the limited pattern dimensions of a horizontal splitting device such as an OPA element.

[0064] As described above, the light spot expansion of individual lights is suppressed through the multilayer lens (60), and additional angular increase can be implemented by the wide-angle lens (70). Accordingly, the number of lights that can be resolved by the 2D transformation lens array structure (80) can be further increased.

[0065] In some embodiments, the wide-angle lens (70) may have two surfaces with different curvatures. In one embodiment, as illustrated in FIG. 2, the curvature of the incident surface facing the multilayer lens (60) may be less than the curvature of the exit surface facing the 2D transformation lens array structure (80). Accordingly, the wide-angle can be expanded more efficiently.

[0066] FIG. 3 is a schematic cross-sectional view showing a 2D transformation lens array structure according to exemplary embodiments.

[0067] Referring to FIG. 3, a 2D transformation lens array structure (80) (hereinafter, may be abbreviated as a lens array structure) may include a lens substrate (85) and lenses (90) arranged on the lens substrate (85).

[0068] The lens substrate (85) may include a transparent material such as glass, quartz, transparent resin, transparent ceramic, etc. For example, a plurality of lenses (90) may protrude convexly from the lens substrate (85) and form an array in the form of an embossed pattern.

[0069] According to exemplary embodiments, a plurality of lenses (90) may be arranged in a row direction or a horizontal direction to form a single row lens array.

[0070] The lens array may include a plurality of heat shift groups. In some embodiments, each of the heat shift groups may include a plurality of lenses (90).

[0071] For example, as illustrated in FIG. 3, the lens array may include a first row shift group (90a), a second row shift group (90b), and a third row shift group (90c).

[0072] The lenses (90) included in the first column shift group (90a) can each shift different horizontally split lights in the column direction and position them in the same row. For example, different horizontally split lights can be positioned in the first row by the first column shift group (90a).

[0073] The lenses (90) included in the second column shift group (90b) can each shift different horizontally split lights in the column direction and position them in the same row. For example, different horizontally split lights can be positioned in the second row shifted in the column direction with respect to the first row by the second column shift group (90b).

[0074] The lenses (90) included in the third column shift group (90c) can each shift different horizontally split lights in the column direction and position them in the same row. For example, different horizontally split lights can be positioned in the third row shifted in the column direction with respect to the first and second rows by the third column shift group (90c).

[0075] As described above, in the embodiment illustrated in FIG. 3, each of the nine lenses (90) can shift individual horizontally divided lights in the column direction and two-dimensionally disperse the nine horizontally divided lights into three rows. Accordingly, the nine lights can be irradiated to different locations in a two-dimensional plane.

[0076] According to exemplary embodiments, the positions of nine individual lights can be assigned in a zigzag manner along the thermal direction to enable continuous optical scanning of the object.

[0077] Therefore, information on the location, distance, speed, etc. of the target object can be easily collected practically in real time, and the detection speed can also be significantly increased.

[0078] The number of lenses (60), the number of column shift groups, and the number of individual lights illustrated in FIG. 3 are examples for convenience of explanation, and may be appropriately adjusted in consideration of the measurement target and the detection performance of the sensor. As described above, by using the multilayer lens (60), the number of horizontally divided lights can be increased, and accordingly, the number of columns and rows in two dimensions in which the horizontally divided lights are distributed and arranged can also be further increased.

[0079] The lenses (90) may have different refractive angles. In some embodiments, the refractive angles of all lenses (90) included in the lens array structure (80) may be different.

[0080] In one embodiment, the lenses (90) may be formed of the same material, have different shapes (different sizes or curvatures, as illustrated in FIG. 3), and have different refractive angles. In one embodiment, the lenses (90) may be formed of different materials and have different refractive indices.

[0081] FIGS. 4 and 5 are schematic cross-sectional views illustrating a 2D transformation lens array structure according to some exemplary embodiments.

[0082] For convenience of illustration, only three lenses or three prism structures are illustrated in FIGS. 4 and 5 , but the number of lenses or prisms may be expanded. The shapes of the lenses / prisms illustrated in FIGS. 4 and 5 are exemplary, and the present disclosure is not limited thereto.

[0083] Referring to FIG. 4, the lens array structure may include both a microlens array and a microprism (e.g., micropyramid) array.

[0084] For example, at least one of the microlens array and the microprism array can provide different refractive angles.

[0085] The above micro lens array may include a first substrate (85a) and sub-lenses (93) arranged on the first substrate (85a). The above micro prism array may include a second substrate (85b) and prism structures (or pyramid structures) (95).

[0086] For example, a single lens can be defined by a sub-lens (93) and a prism structure (95) that overlap each other in the direction of light propagation, and a plurality of lenses can provide different refractive angles.

[0087] In one embodiment, the horizontally split light beams can sequentially pass through the micro lens array and the micro prism array. Even when the sub-lenses (93) have the same shape (e.g., provide the same angle of refraction), the horizontally split light beams can be thermally shifted through the micro prism array at different angles of refraction as described above.

[0088] In one embodiment, the horizontally split lights may sequentially pass through the micro-prism array and the micro-lens array.

[0089] Referring to FIG. 5, composite lenses (97) in which lens and prism structures are integrated with each other can be arranged on a lens substrate (85) to form a lens array structure. Each of the composite lenses (97) has a different shape depending on the incorporation of the prism structures and can provide different refractive angles.

[0090] The lens array structure (80) may include an array of interference patterns or diffraction patterns using Fresnel lenses. In one embodiment, the lens array structure (80) may be formed using a meta-lens.

[0091] Figure 6 is a schematic drawing for explaining light splitting by a lens according to a comparative example.

[0092] Referring to FIG. 6, horizontally split light from a horizontal splitting device (130) such as an OPA element may be point-split while passing through a single lens (40). The light angle between neighboring lights may increase and be dispersed through the single lens (40). However, the beam size may increase while passing through the single lens (40), and the area of ​​each of the light spots (λ1, λ2, λ3, λ4, λ5) may increase. Accordingly, in order to encompass a large number of lights while avoiding overlapping of waveforms included in the light spots (λ1, λ2, λ3, λ4, λ5), the size of the entire optical device, the lens structure, may be excessively increased.

[0093] FIG. 7 is a schematic diagram illustrating light splitting by a multi-lens structure according to exemplary embodiments.

[0094] Referring to Fig. 7, as described above, a multilayer lens (60), such as an F-theta lens, may be employed instead of a single lens (40). In this case, as illustrated in Fig. 6, the horizontally split light beams can be divided into points and dispersed to form a smaller focal area while preventing an increase in the light spot size.

[0095] In some embodiments, the split light passing through the multilayer lens (60) may have its wide angle further increased as it passes through the wide-angle lens (70).

[0096] Therefore, the size of each of the light spots (λ1, λ2, λ3, λ4, λ5) can be reduced, and the distance between neighboring light spots (λ1, λ2, λ3, λ4, λ5) can be increased. Therefore, additional light spots can be inserted between neighboring light spots (λ1, λ2, λ3, λ4, λ5) while avoiding waveform overlap (e.g., λ1a, λ1b, λ2a, λ2b, λ3a, λ3b, λ4a, λ4b).

[0097] Accordingly, the resolution and precision of optical scanning or optical sensing can be improved. In addition, the increased number of optical spots can be two-dimensionally dispersed using a 2D transformation lens array structure (80) to implement three-dimensional optical scanning. The 2D transformation lens array structure (80) can include a lens (90) corresponding to each of the increased number of optical spots.

[0098] FIG. 8 is a schematic block diagram illustrating an optical scanning device according to exemplary embodiments.

[0099] The term "optical scanning device" as used in this application is used as a comprehensive term for a sensor that illuminates a target object with light and detects information about the target object through the reflected light. According to exemplary embodiments, the optical scanning device may include, but is not limited to, a lidar sensor.

[0100] Hereinafter, an optical scanning device and a measurement method using the same will be described with reference to FIGS. 8 to 11.

[0101] Referring to FIG. 8, the optical scanning device (100) may include a light source (110) and a vertical split lens array (140). The optical scanning device (100) may further include a horizontal split device (130) disposed between the light source (110) and the vertical split lens array (140).

[0102] According to exemplary embodiments, the light source (110) may be a device that irradiates light in the infrared region. By using light in the infrared region, mixing with natural light, including, for example, visible light, can be prevented. However, the light transmitted from the light source (110) is not limited to infrared, and light of multiple different wavelength bands may be emitted simultaneously.

[0103] In some embodiments, the wavelength of light emitted from the light source (110) may be between 1500 nm and 2000 nm. In one embodiment, the wavelength may be between 1520 nm and 1580 nm, or between 1520 nm and 1560 nm. In this wavelength range, the deterioration of detection performance due to light scattering can be prevented while reducing the harmfulness to the human eye.

[0104] According to exemplary embodiments, continuous light can be irradiated from a light source (110).

[0105] In some embodiments, the light source (110) may include a laser light source. For example, the light source (110) may include an edge emitting laser, a vertical-cavity surface emitting laser (VCSEL), a distributed feedback laser, a laser diode, or the like.

[0106] In some embodiments, the transmitted light generated from the light source (110) may be amplified by the amplifier (120). Accordingly, the intensity of the transmitted light is increased, and the intensity of the received light is prevented from being weakened while passing through the light splitting devices described below.

[0107] The light transmitted from the light source (110) or the light amplified through the amplifier (120) can be split by a light splitting device. According to exemplary embodiments, the light splitting device can include a horizontal splitting device (130) and a vertical splitting lens array (140). The horizontal splitting device (130) and the vertical splitting lens array (140) can be sequentially arranged from the light source (110).

[0108] The transmitted light from the light source (110) or the light amplified through the amplifier (120) can be split into a plurality of horizontal lights through the horizontal splitting device (130). For example, the transmitted light from the light source (110) can generate a plurality of horizontally split lights having an angular difference or a phase difference in the X-direction (row direction) plane.

[0109] According to exemplary embodiments, the horizontal splitting device (130) may include an optical phased array (OPA) element. The configuration / structure of the horizontal splitting device (130) including the OPA element is described in more detail below with reference to FIG. 10.

[0110] Lights horizontally divided by the horizontal division device (130) can be vertically divided / distributed by the vertical division lens array (140). For example, the horizontally divided lights can be given an angular difference in the y-axis direction by the vertical division lens array (140). Accordingly, light transmitted from the light source (110) can be dispersed in the horizontal direction and then dispersed in the vertical direction to generate vertically distributed lights. Accordingly, the transmitted lights can have two-dimensionally different phases or positions, and the identification characteristics of each light can be enhanced.

[0111] According to embodiments of the present invention, a 2D transformation lens array structure (80) described with reference to FIGS. 3 to 5 may be applied as a vertical split lens array (140).

[0112] As described above, the transmitted light can be split / dispersed into different positions in a two-dimensional plane through the light splitting device and can be continuously incident on the target object (160). The light reflected by the target object (160) can be input to the detector (170). The received light can be converted into an electrical signal by the detector (170). For example, a current can be output by the detector (170).

[0113] In exemplary embodiments, the detector (170) may include at least one pixel. For example, the detector (170) may include a plurality of pixels arranged in an array or matrix form. Each of the pixels may function as a light-receiving element and output an electrical signal, such as a current, corresponding to the reflected light. Information, such as the direction or position of the target object (160), may be generated based on the position of the pixel that detected the corresponding light among the pixels.

[0114] For example, the distance to the target object (160) can be calculated based on the light emission time of the light source (110) and the light detection time of the detector (170).

[0115] The above pixel may be a photodetector that operates under an applied bias voltage. For example, the detector (170) may include an avalanche photodiode (APD) or a single photon avalanche diode (SPAD).

[0116] The electrical signal generated from the detector (170) can be processed and calculated through the processor (180). For example, the processor (180) can determine location information about the target object (160) using the detection result of the detector (170). The location information about the target object (160) can include at least one of the direction, height, and distance of the target object (160).

[0117] Additionally, as described below, real-time positional changes of the object (160) can be detected through continuous optical scanning. Accordingly, velocity information can be derived together with positional information of the object (160).

[0118] The processor (180) may also control the operation of the light source (110). For example, the light emission operation may be controlled through the processor (180).

[0119] The optical scanning device (100) may further include a lens structure. According to exemplary embodiments, the lens structure may include a first lens structure (150a) disposed between the horizontal split device (130) and the vertical split lens array (140), and a second lens structure (150b) disposed between the vertical split lens array (140) and the target (160).

[0120] The first lens structure (150a) includes a multilayer lens (60) according to the exemplary embodiments described above, and may further include a wide-angle lens (70). According to exemplary embodiments, the multi-lens structure (50) described above may be applied as the first lens structure (150a) and the vertically split lens array (140).

[0121] The light source (110) and the amplifier (120) are connected to each other through a first optical path (LP1), and the amplifier (120) and the horizontal splitter (130) can be connected to each other through a second optical path (LP2). The optical paths (LP1, LP2) are formed of optical fibers and can suppress optical transmission loss.

[0122] Fig. 9 is a schematic block diagram illustrating an optical scanning device according to exemplary embodiments. Detailed descriptions of configurations and operations substantially the same as or similar to those described with reference to Fig. 8 are omitted.

[0123] Referring to FIG. 9, as described later with reference to FIG. 10, horizontal distribution light paths (135) included in the horizontal division device (130) may include detection distribution light paths (134) and reference distribution light paths (136). Reference light may be generated through the reference distribution light path (136), and target light may be generated through the detection distribution light paths (134).

[0124] The detector (170) may include a first detector (173) and a second detector (175). The reference light generated through the reference distribution optical path (136) may be directly introduced into the second detector (175). The target light generated through the detection distribution optical paths (134) may be horizontally and vertically divided through the multi-lens structure (50), and then reflected by the target object (160) and introduced into the first detector (173).

[0125] The above target lights can be more clearly identified based on the reference light recognized through the second detector (175). In addition, the position information of the object (160) can be processed / generated in high resolution through the target signal generated by the target lights based on the reference signal generated based on the reference light through the processor (180).

[0126] According to exemplary embodiments, the first detector (173) may be a single detector that continuously detects the target lights.

[0127] FIG. 10 is a schematic perspective view showing a horizontal splitting device according to exemplary embodiments.

[0128] Referring to FIG. 10, as described above, the horizontal splitting device (130) may include an OPA element. The horizontal splitting device (130) may include a substrate (131) and horizontal distribution optical paths (e.g., waveguides) (135) formed on the upper surface of the substrate (131).

[0129] For example, light emitted from a light source (110) may be input to an optical input unit (132) included in a horizontal splitter (130) via an amplifier (120). The input light may be input to horizontal distribution optical paths (135) via a splitter included in a branching area of ​​the horizontal distribution optical paths (135). The splitter may have, for example, an MMI (multimode interference) structure.

[0130] Light input into each of the horizontal distribution optical paths (135) can be converted to have different phases by a phase modulator. The phase modulator can be included in each of the horizontal distribution optical paths (135) and can perform light modulation through electrical, magnetic, thermal, mechanical, etc. methods.

[0131] In some embodiments, the horizontal distribution paths (135) may include detection distribution paths (134) and reference distribution paths (136). Reference light may be generated through the reference distribution path (136), and target light may be generated through the detection distribution paths (134).

[0132] For example, a reference signal corresponding to the reference light and a target signal corresponding to the target light can be generated through the processor (180). Using the correlation between the reference signal and the target signal, location information of the object (160) can be generated with high reliability. In addition, the identification of the target light can be increased through the reference light.

[0133] The horizontal splitting device (130) may include a transparent material capable of suppressing light loss. For example, the horizontal splitting device (130) may include Si, Ge, SiGe, or an oxide or nitride thereof.

[0134] According to the exemplary embodiments described above, by combining the horizontal segmentation device (130) and the vertical segmentation lens array (140), two-dimensional or three-dimensional optical scanning can be practically implemented. Accordingly, positional information, including the distance and height of the target object (160), can be calculated with higher precision.

[0135] Additionally, vertical segmentation using mechanical elements such as motors or rotors can be eliminated. As described above, a lens array, which is an optical element, can be employed as a vertical segmentation device, thereby reducing or suppressing detection errors caused by vibration and shock.

[0136] Vertical light splitting having substantially point-split characteristics can be realized through the vertical split lens array (140). For example, light passing through the horizontal split device (130) can be horizontally point-split through the first lens structure (150a). The horizontally point-split light can be vertically point-split through the vertical split lens array (140).

[0137] Accordingly, practical continuous real-time optical scanning can be implemented with a single detector for target lights, and a Frequency Modulated Continuous Wave (FMCW) type lidar sensor can be implemented.

[0138] For example, in a TOF (Time of Flight) type lidar sensor based on a single optical pulse, the sensing sensitivity may decrease due to the weakening of the optical pulse depending on the atmospheric environment. However, according to exemplary embodiments, the sensing sensitivity can be effectively maintained through continuous optical scanning, and information on the speed of the target object (160) can be calculated in real time based on continuous measurements.

[0139] In some embodiments, the TOF type lidar sensor can also be implemented using the above-described optical scanning device or 2D conversion lens array structure.

[0140] Additionally, vertical splitting is implemented using optical elements that do not require a separate power supply, thereby improving light / power efficiency.

[0141] FIG. 11 is a cross-sectional view illustrating a second lens structure according to exemplary embodiments.

[0142] Referring to FIG. 11, the second lens structure (150b) may include a substrate (200) and lens portions (210) formed on the substrate (200). For example, a plurality of lens portions (210) may protrude convexly from the substrate (200) and form an array in the form of an embossed pattern.

[0143] According to exemplary embodiments, a plurality of lens elements (210) may be arranged in a horizontal direction (e.g., in the X direction) to form a lens row. For example, the lens elements (210) may form a microlens array.

[0144] The second lens structure (150b) may be provided as a position-specific correction lens. Each of the lens units (210) included in the second lens structure (150b) may correspond to each of the lenses (90) included in the vertically divided lens array (140) or the 2D transformation lens array structure (80). For example, the lens units (210) included in the second lens structure (150b) and the lenses (90) included in the vertically divided lens array (140) may be matched 1:1.

[0145] The second lens structure (150b) can additionally provide a wide angle to the light passing through the vertically split lens array (140). In addition, the intensity and area of ​​the light can be uniformly adjusted, making it easy to implement a substantially uniform 2D scan.

[0146] Additionally, the light collection characteristics toward the target object (160) can be improved through the second lens structure (150b). Accordingly, the detection intensity through the detector (170) can be improved while additionally increasing the intensity of reflected light.

Claims

1. Concentrating lens; and A multi-lens structure comprising a 2D transformation lens array structure that disperses light passing through the collecting lens in a vertical direction.

2. A multi-lens structure according to claim 1, wherein the focusing lens comprises a multilayer lens including an F-theta lens.

3. A multi-lens structure according to claim 2, further comprising a wide-angle lens disposed between the multilayer lens and the 2D transformation lens array structure.

4. In claim 3, the wide-angle lens is a multi-lens structure having two surfaces having different curvatures.

5. A multi-lens structure according to claim 4, wherein the curvature of the incident surface facing the multilayer lens among the surfaces of the wide-angle lens is smaller than the curvature of the exit surface facing the 2D transformation lens array structure.

6. In claim 1, the 2D transformation lens array structure, Lens material; and A multi-lens structure comprising lenses arranged in a row direction on the above lens substrate and having different refractive angles.

7. A multi-lens structure according to claim 6, wherein the lenses form column shift groups that distribute horizontally split light into a plurality of columns.

8. In claim 6, the lens substrate includes a first substrate and a second substrate, A multi-lens structure, wherein the lenses include a micro lens array arranged on the first substrate and a micro prism array arranged on the second substrate.

9. In claim 6, the lenses include composite lenses in which micro lenses and micro prism structures are integrated. A multi-lens structure.

10. A multi-lens structure according to claim 6, wherein the lenses include interference patterns including Fresnel lenses.

11. In claim 6, the lenses included in the 2D transformation lens array structure are a multi-lens structure, each corresponding to a light spot generated through the focusing lens.

12. Light source; A horizontal splitting device that generates horizontally split lights from light emitted from the light source; A multi-lens structure according to claim 1 for passing the horizontally divided lights and irradiating the lights to the target object; and An optical scanning device, comprising a detector for detecting light reflected from a target object by light irradiated from the multi-lens structure.

13. An optical scanning device according to claim 12, wherein the horizontal segmentation device includes an optical phased array (OPA) element.

14. An optical scanning device according to claim 12, wherein the spot area of ​​each of the horizontally split lights is reduced by the focusing lens included in the multi-lens structure.

15. In claim 14, the multi-lens structure further includes a wide-angle lens arranged between the focusing lens and the 2D transformation lens array structure, An optical scanning device, wherein the wide angle between the horizontally split lights collected by the collecting lens through the wide-angle lens is increased.

16. An optical scanning device according to claim 12, wherein vertically split light beams are generated by the 2D transformation lens array structure included in the multi-lens structure.

17. An optical scanning device according to claim 12, further comprising a second lens structure disposed between the multi-lens structure and the target object to perform positional correction.

18. An optical scanning device according to claim 12, further comprising an amplifier disposed between the light source and the horizontal splitting device.

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