Receiving optical system, sensor system, and lidar device

Abstract

A receiving optical system according to the present embodiment comprises first to sixth lenses sequentially arranged from an object side to a sensor side along the optical axis, wherein the first lens has negative (-) refractive power, at least one of the second to sixth lenses has positive (+) refractive power, and among the gaps between lenses adjacent to each other along the optical axis, the center gap between the second lens and the second lens is the greatest.

Description

Receiving optics, sensor systems and lidar devices

[0001] The embodiment relates to a receiving optical system and a sensor system having the same.

[0002] The embodiment relates to a receiving optical system for LIDAR (Light detection and ranging) and a device having the same.

[0003] An embodiment of the invention relates to a mobile body having a receiving optical system and system for lidar.

[0004] ADAS (Advanced Driving Assistance System) is an advanced driver assistance system that assists the driver in driving. It consists of sensing the situation ahead, judging the situation based on the sensed results, and controlling the vehicle's behavior based on the situation judgment. For example, ADAS sensor devices detect a vehicle ahead and recognize lanes. After the target lane, target speed, and forward target are determined, the vehicle's ESC (Electrical Stability Control), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Representative examples of ADAS can be implemented as automatic parking systems, low-speed city driving assistance systems, and blind spot warning systems.

[0005] With the recent surge in interest in autonomous vehicles, demand for LiDAR (Light Detection And Ranging) sensors, a key component of autonomous vehicles, is growing. Currently, LiDAR is used only in high-end, expensive vehicles, but its adoption in general-purpose vehicles is expected to increase as manufacturing costs decline.

[0006] Ultra-small and ultra-light lidar technology can be used not only as a sensor for unmanned mobile devices, but also in satellites and aerospace for observing the Earth's topography and environment, unmanned vehicles, transporters, cranes, and robots used in factories and shipyards, and it is expected to appear in the form of complex or cooperative operation between mobile devices through an integrated approach in the land, aviation, and marine industries. Therefore, the development of an optical system for ultra-small and ultra-light lidar to implement ultra-small and ultra-light lidar is urgent.

[0007] The present invention provides a receiving optical system having improved optical characteristics and a sensor system and a lidar device having the same.

[0008] The embodiment seeks to provide a receiving optical system and a sensor system having the same.

[0009] The present invention seeks to provide a receiving optical system, a sensor system, and a lidar device having improved thermal compensation characteristics.

[0010] In order to solve the above technical problem, the receiving optical system according to the present embodiment includes first to sixth lenses sequentially arranged from the object side to the sensor side along the optical axis, the first lens has negative (-) refractive power, at least one of the second to sixth lenses has positive (+) refractive power, and among the distances between adjacent lenses on the optical axis, the distance between the centers of the second lens and the second lens is the largest.

[0011] In the optical axis, the first lens may have a concave shape on both sides, and in the optical axis, the second lens may have a convex shape on both sides.

[0012] In the optical axis, the fourth lens may have a meniscus shape with an object side convex, and in the optical axis, the fifth lens may have a meniscus shape with an object side convex.

[0013] The second to sixth lenses have positive (+) refractive power, and a filter may be placed between the third lens and the fourth lens.

[0014] Among the first to sixth lenses, the effective diameter of the fourth lens may be the largest, and among the first to sixth lenses, the effective diameter of the sixth lens may be the smallest.

[0015] The center spacing between the second lens and the third lens on the optical axis may be greater than the center thickness of the fourth lens.

[0016] The effective diameter size of the first to sixth lenses may be larger than the maximum diagonal length of the image sensor.

[0017] It may include a filter placed adjacent to the lens having the largest effective diameter among the first to sixth lenses.

[0018] The following condition can be satisfied. <Condition> 0.1 < F / TTL < 0.5 (In the above condition, F is the total focal length of the receiving optical system, and TTL is the total optical axis length of the receiving optical system.)

[0019] The following condition can be satisfied. <Condition> 1 < ┃F1┃ / F < 3 (In the above condition, F1 is the focal length of the first lens, and F is the overall focal length of the receiving optical system.)

[0020] The following condition can be satisfied. <Condition> 0.5 < CA_L1 / CA_L2 < 1 (In the above condition, CA_L1 is the size of the effective diameter of the first lens, and CA_L2 is the size of the effective diameter of the second lens.)

[0021] In order to solve the above technical problem, the lidar device according to the present embodiment includes a receiving optical system including an image sensor and first to sixth lenses sequentially arranged from an object side to a sensor side along a first axis; and a transmitting optical system including a light source and seventh to twelfth lenses sequentially arranged from an object side to a light source side along a second optical axis, and includes a first filter arranged adjacent to a lens having a largest effective diameter among the first to sixth lenses, and a second filter arranged adjacent to a lens having a largest effective diameter among the seventh to twelfth lenses, and a distance between the second lens and the third lens on the optical axis is greater than a distance between the fifth lens and the sixth lens.

[0022] The first lens may have negative (-) refractive power, and the seventh lens may have negative (-) refractive power.

[0023] The first to sixth lenses are made of glass, and at least one of the object-side surface and the sensor-side surface of the sixth lens may have an aspherical surface.

[0024] In the optical axis, the second lens and the third lens may have a convex shape on both sides, and the fourth to sixth lenses in the optical axis may have a meniscus shape convex toward the object side.

[0025] In an embodiment, improved optical characteristics can be achieved. Specifically, in a receiving optical system according to an embodiment, the position of the bandpass filter can be positioned near the stop to minimize the incident angle of light entering the filter. Accordingly, the transmittance range of the bandpass filter can be broadly utilized depending on the incident angle of light of the bandpass filter.

[0026] According to an embodiment, it can have improved optical characteristics. The lidar receiving optical system of the invention can maximize the extraction efficiency of light emitted from the receiving optical system.

[0027] The lidar receiving optical system of the invention can have good optical properties in a low to high temperature range. Specifically, a plurality of lenses included in the receiving optical system can have set materials, refractive powers, and refractive indices. Accordingly, when the refractive index of each lens changes due to temperature changes and the focal length of each lens changes as a result, mutual compensation can be made by the glass mold lens and the glass lens. In other words, the receiving optical system can effectively distribute refractive power in a low to high temperature range, and can prevent or minimize changes in optical properties in a low to high temperature range. Therefore, the optical system and sensor system according to the embodiment can maintain improved optical properties in various temperature ranges.

[0028] The lidar receiving optical system of the invention may have lenses with set thicknesses, refractive powers, and spacings from adjacent lenses. Accordingly, the optical system and sensor system according to the embodiment may have improved MTF characteristics, aberration control characteristics, resolution characteristics, etc. within a set field of view range, and may have good optical performance in the periphery of the field of view.

[0029] The receiving optical system and sensor system according to the embodiment can achieve excellent optical characteristics while satisfying a set field of view through a combination of a glass molded lens and a glass lens. This allows the optical system to provide a slimmer vehicle sensor system. Accordingly, the optical system and sensor system can be used in various applications and devices, and can maintain excellent optical characteristics even in harsh temperature environments, such as when exposed to the exterior of a vehicle or in the high temperatures of a vehicle interior during the summer.

[0030] Fig. 1 is a side cross-sectional view of a receiving optical system of a lidar according to the present embodiment.

[0031] Fig. 2 is a table showing the lens characteristics of the receiving optical system of Fig. 1.

[0032] Fig. 3 is a table showing the lens characteristics of the receiving optical system of Fig. 1.

[0033] Fig. 4 is a table showing the aspherical coefficients of lenses in the receiving optical system of Fig. 1.

[0034] Figure 5 is a table showing the lens characteristics of the receiving optical system of Figure 1 in mathematical form.

[0035] Fig. 6 is a graph showing data of diffraction MTF (Modulation Transfer Function) in the receiving optical system of Fig. 1.

[0036] Fig. 7 is a block diagram showing a sensor system having a receiving optical system of the present invention.

[0037] FIG. 8 is a cross-sectional side view showing a transmission optical system according to one embodiment of the sensor system of FIG. 7.

[0038] FIG. 9 is a drawing showing an example of measuring an object in a vehicle having a sensor system of the invention.

[0039] Fig. 10 is a drawing showing an example of surrounding surveillance in a vehicle having a sensor system of the invention.

[0040] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. 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 one or more of the components between the embodiments can be selectively combined or substituted within the scope of the technical idea of ​​the present invention. In addition, terms (including technical and scientific terms) used in the embodiments of the present invention can be interpreted as having a meaning that can be generally understood by a person having 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, can be interpreted in consideration of the contextual meaning of the related technology.

[0041] The terminology used in the embodiments of the present invention is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when it is described as “A and (or at least one) of B, C”, it may include one or more of all combinations that can be combined with A, B, and C. In addition, when describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and are not limited by the nature, order, or sequence of the components. In addition, when it is described that a component is “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. Additionally, when it is 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 it is expressed as "above" or "below", it can include the meaning of the downward direction as well as the upward direction based on one component.

[0042] In the description of the invention, the “object-side surface” may mean a surface of a lens facing the object side with respect to the optical axis (OA), the “sensor-side surface” may mean a surface of a lens facing the imaging surface (image sensor) with respect to the optical axis, and the “light source-side surface” may mean a surface of a lens facing the light source with respect to the optical axis. A convex surface of a lens may mean a convex shape in the optical axis or the paraxial region, and a concave surface of a lens may mean a concave shape in the optical axis or the paraxial region. The radius of curvature, center thickness, and optical axis spacing between lenses described in a table for lens data may mean values ​​(unit: mm) in the optical axis. The vertical direction may mean a direction perpendicular to the optical axis, and the end of a lens or lens surface may mean the end of an effective area of ​​a lens through which incident light passes. The size of the effective diameter of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method, etc. The term "paraxial region" refers to a very narrow region near the optical axis, where the distance from the optical axis (OA) to which light rays fall is almost zero. Hereinafter, the term "optical axis" may include the center of each lens or a very narrow region near the optical axis.

[0043]

[0044] FIG. 1 is a side cross-sectional view of a receiving optical system of a lidar according to the present embodiment, FIG. 2 is a table showing lens characteristics of the receiving optical system of FIG. 1, FIG. 3 is a table showing lens characteristics of the receiving optical system of FIG. 1, FIG. 4 is a table showing aspherical coefficients of lenses in the receiving optical system of FIG. 1, FIG. 5 is a table showing lens characteristics of the receiving optical system of FIG. 1 in mathematical formulas, and FIG. 6 is a graph showing data of diffraction MTF (Modulation Transfer Function) in the receiving optical system of FIG. 1.

[0045] A receiving optical system (100) and a sensor system having the same can be mounted inside or outside a vehicle to monitor the driver or sense external objects or lanes. The lens material can be selected from glass or plastic, and the coefficient of linear expansion of glass is lower than that of plastic. Glass lenses are used to suppress changes in the focal point position due to temperature changes. However, when configuring an optical system with spherical glass lenses, there is a limit to reducing the number of lenses, and there are also limitations to reducing size and weight.

[0046] The receiving optical system (100) of the present embodiment may include a spherical lens and an aspherical lens. Here, a spherical lens is a lens in which at least one of the object-side surface and the sensor-side surface of the lens is spherical. An aspherical lens is a lens in which at least one of the object-side surface and the sensor-side surface of the lens is aspherical. The receiving optical system (100) may include a spherical glass lens and an aspherical glass lens. In addition, by employing an aspherical lens, the optical system (100) may have a reduced overall length (TTL), and the aspherical lens may enable good correction for various aberrations such as spherical aberration and chromatic aberration. In addition, the aspherical lenses may minimize distortion in the peripheral area.

[0047] The optical system (100) may include n lenses, where the nth lens may be the last lens adjacent to the image sensor (300), and the (n-1)th lens may be the lens closest to the last lens. n is an integer greater than or equal to 2, and may be, for example, in the range of 6 to 8. The ratio of spherical lenses to aspherical lenses in the n lenses may be 5:1 or 6:1.

[0048] The receiving optical system (100) may include a first lens made of glass. Glass exhibits minimal expansion and contraction changes due to external temperature changes, and its surface is less susceptible to scratches, preventing surface damage. Accordingly, the object-side lenses in the optical system (100) may be spherical lenses, and the sensor-side lenses may be aspherical lenses.

[0049] At least one lens closest to the image sensor (300) within the optical system (100) may be an aspherical lens. At least one lens closest to the image sensor (300) may be an aspherical lens. Since the nth or n-1th lenses in the optical system (100) are arranged as aspherical lenses, various paths can be formed for light incident on the image sensor (300). The aspherical lens may be a glass mold made of injection-molded glass material.

[0050] Within the optical system (100), at least two lenses closest to the object may be made of glass. More than two lenses, for example, two to five lenses, closest to the object may be made of glass. Since glass lenses exhibit a smaller rate of contraction and expansion due to temperature changes than plastic lenses, the glass lenses may be positioned in an area adjacent to the outside within the lens barrel.

[0051]

[0052] Each lens may have an object-side surface and a sensor-side surface. The lenses may include lenses having an object-side spherical surface and a sensor-side spherical surface, and lenses having an object-side aspherical surface and a sensor-side aspherical surface. The optical system may have a smaller number of aspherical lenses than spherical lenses. The optical system (100) may correct various aberrations by arranging the aspherical lenses adjacent to the image sensor (300). The spherical lenses may be made of glass, and the aspherical lenses may be made of glass molded material.

[0053] Among the lenses of the optical system (100), the lens with the highest refractive index may be a spherical lens, and the lens with the highest Abbe number may be a spherical lens. Accordingly, since the lens with the highest refractive index is placed on the object side, it is easy to change the radius of curvature of the second and subsequent lenses, and the central thickness can be increased.

[0054] The lens with the largest effective diameter within the optical system (100) is located in the central region of the optical system (100), is made of glass, and may be a spherical lens. The lens with the smallest effective diameter within the optical system (100) is located between the lenses closest to the sensor side, and may be a glass mold lens. In addition, the average effective diameter of the aspherical lenses may be smaller than the average effective diameter of the spherical lenses. Here, the effective diameter of the lens is the average value of the effective diameter of the object-side surface of each lens and the effective diameter of the light source-side surface.

[0055] Each of the lenses (101 to 106) may include an effective area and an ineffective area. The effective area may be an area through which light incident on each of the lenses passes. In other words, the effective area may be defined as an effective area or effective diameter through which the incident light is refracted to implement optical characteristics. The ineffective area may be arranged around the periphery of the effective area. The ineffective area may be an area through which effective light is not incident from a plurality of lenses. In other words, the ineffective area may be an area unrelated to the optical characteristics. In addition, an end of the ineffective area may be an area fixed to a lens barrel (not shown) that accommodates the lens.

[0056]

[0057] Among the lenses of the optical system (100), the lens having the greatest central thickness may be a spherical lens, and the lens having the greatest edge thickness may be a spherical lens. Accordingly, various aberrations can be corrected, and optical performance can be improved even to the periphery.

[0058] Within the optical system (100), the TTL (Total top length) may be more than 8 times, for example, more than 8 times and less than 12 times, than the ImgH. The TTL (Total track length) is the distance from the center of the object-side surface of the first lens to the top surface of the image sensor (300) on the optical axis (OA). The ImgH is twice the distance from the center of the image sensor (300) to the diagonal end or the maximum diagonal length of the image sensor (300). In addition, the effective diameter of each lens within the optical system (100) may be greater than the diagonal length of the image sensor (300).

[0059] Within the optical system (100), the effective focal length (EFL) can satisfy a range of 8 mm or more and 12 mm or less. The field of view (FOV) of the optical system (100) can satisfy a range of 10 degrees or more and 30 degrees or less. Through this, it can be provided as a standard receiving optical system in a vehicle sensor system. For example, the receiving optical system and sensor system according to the embodiment can be applied to a sensing device for an Advanced Driving Assistance System (ADAS) installed inside or outside a vehicle.

[0060]

[0061] The optical system (100) may have a TTL / ImgH condition of greater than 4, for example, greater than 4 and less than 10. Accordingly, the central thickness of each lens along the optical axis (OA) can be increased and the size of the image sensor (300) can be reduced, thereby providing a vehicle lens optical system. In addition, temperature compensation must be applied within the temperature range that serves as the temperature reliability evaluation standard for automotive electrical components for use in vehicle cameras, i.e., from -40°C to +120°C.

[0062] That is, the lens must be configured so that the focus of the lens remains within a set range even when the lens expands or contracts due to changes in temperature. The lens can be configured with a total effective focal length (EFL) of 15 mm or less, for example, in the range of 5 mm to 15 mm or 8 mm to 12 mm, and made of a glass material capable of the aforementioned temperature compensation.

[0063] In the optical system (100), the number of lenses with positive (+) refractive power may be greater than the number of lenses with negative (-) refractive power. The number of lenses with positive (+) refractive power may be 60% or more of the total number of lenses. The average refractive index of the lenses with negative (-) refractive power may be greater than the average of the lenses with positive (+) refractive power. Accordingly, the dispersion value of the lenses with positive (+) refractive power may be greater than the dispersion value of the lenses with negative (-) refractive power. Since the optical system (100) is a mixture of a spherical lens and an aspherical lens made of glass, various aberrations can be corrected, thereby preventing deterioration of optical performance.

[0064] The effective diameter of the lens closest to the object side within the optical system (100) may be larger than the effective diameter of the lens closest to the image sensor (300). Accordingly, the brightness of the optical system can be controlled. By controlling the effective diameter size of each lens, the optical system (100) can control the incident light to compensate for the deterioration of resolution and optical characteristics due to temperature changes, improve chromatic aberration control characteristics, and improve the vignetting characteristics of the optical system (100).

[0065] The optical system (100) may include a first lens (101), a second lens (102), a third lens (103), a fourth lens (104), a fifth lens (105), and a sixth lens (106) aligned from the object side toward the sensor side along the optical axis (OA). The first to sixth lenses (101, 102, 103, 104, 105, 106) may be defined as a lens unit.

[0066] When the radius of curvature is described as an absolute value, the lens surface having the minimum radius of curvature with respect to the optical axis (OA) within the optical system (100) may be the object-side surface of the sixth lens (106) among the spherical surfaces. The lens surface having the maximum radius of curvature within the optical system (100) may be the object-side and sensor-side surfaces of the third lens (103) among the spherical surfaces. When the radius of curvature of the lenses is adjusted, diffuse reflection between adjacent lens surfaces can be prevented, thereby reducing lens ghosting, and also preventing (MPI: Multi-path interference) caused by lens ghosting.

[0067] The optical system (100) or sensor system may include an image sensor (300). The image sensor (300) can detect light and convert it into an electrical signal. The image sensor (300) can detect light that has sequentially passed through lenses. The image sensor (300) may include a device capable of detecting incident light, such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0068] Here, the length of the image sensor (300) is the maximum length in the diagonal direction orthogonal to the optical axis (OA), and here, the number of lenses having an effective diameter larger than the length of the image sensor (300) is 4 to 6, and there may be no number of lenses having an effective diameter smaller than the length of the image sensor (300).

[0069]

[0070] The optical system (100) may include a filter (111), and the filter (111) may be arranged within the lens unit. The filter (111) may transmit a laser beam incident on the receiving optical system and block beams of other wavelengths. The transmitted laser beam may be in the range of 890 nm to 960 nm or 940 nm ±10 nm.

[0071] At least three lenses may be arranged between the filter (111) and the image sensor (300). For example, the fourth, fifth, and sixth lenses (104, 105, and 106) may be arranged between the filter (111) and the image sensor (300). An aspherical lens may be arranged between the filter (111) and the image sensor (300). The filter (111) may be a band pass filter that passes a laser beam in the range of 890 nm to 960 nm or 940 nm ± 10 nm. The filter (111) may pass light having a wavelength corresponding to the laser beam transmitted from the transmission optical system of the lidar device and block light corresponding to the remaining ambient light.

[0072] The filter (111) may be placed between two different lenses among the lenses. The filter (111) may be placed between the third lens (103) and the fourth lens (104). The gap (CG3-1) between the filter (111) and the third lens (103) and the gap (CG3-2) between the filter (111) and the fourth lens (104) may be the smallest among the gaps between adjacent lenses. The center gap (CG3) between the third lens (103) and the fourth lens (104) may be larger than the thickness of the filter (111). The center gap between the third lens (103) and the fourth lens (104) is equal to the sum of the gap between the third lens (103) and the filter (111), the center thickness of the filter (111), and the gap between the filter (111) and the fourth lens (104).

[0073]

[0074] The cover glass (112) is placed between the sixth lens (106) and the image sensor (300), and protects the upper portion of the image sensor (300) and can prevent the reliability of the image sensor (300) from being deteriorated. The cover glass (112) can be removed. The cover glass (112) may be a protective glass.

[0075] The optical system (100) may include an aperture (ST: Stop). The aperture (ST) may control the amount of light incident on the optical system (100). The aperture (ST) may be arranged between the first lens (101) and the second lens (102). The aperture (ST) may be arranged between the spherical first lens (101) and the spherical second lens (102). The aperture (ST) may be arranged between the sensor-side spherical surface of the first lens (101) and the object-side spherical surface of the second lens (102). The aperture (ST) may be arranged between the first lens (101) and the filter (111).

[0076] The lens surface on which the aperture (ST) is arranged is intended to more efficiently control and guide the amount of light of the optical system (100). The aperture (ST) may be arranged on the sensor-side surface of the first lens (101). The aperture (ST) may be arranged on the object-side surface of the second lens (102). Alternatively, at least one lens selected from among a plurality of lenses, for example, the object-side surface or the sensor-side surface of the first lens (101), may function as an aperture.

[0077]

[0078] In the optical system (100), the sum of the refractive indices of the lenses may be 8.0 or more, for example, in the range of 8.0 to 12.0, and the average of the refractive indices may be in the range of 1.70 to 1.80. The sum of the Abbe numbers of each of the lenses may be 220 or less, for example, in the range of 150 to 220, and the average of the Abbe numbers may be 50 or less, for example, in the range of 25 to 50. By controlling the refractive indices of the lenses in the optical system (100), it is possible to prevent degradation of optical performance for temperature changes from -45 to 120 degrees and to optimize thermal compensation. In addition, by controlling the Abbe number, it is possible to minimize the deviation of the spot size of incident light, i.e., to minimize the spot diagram size.

[0079] The sum of the central thicknesses of the entire lens may be 20 mm or more, for example, in the range of 25 mm to 35 mm, and the average of the central thicknesses may be 5.5 mm or less, for example, in the range of 4.8 mm to 5.3 mm. The sum of the central spacings between the lenses on the optical axis (OA) may be 15 mm or more, for example, in the range of 15 mm to 20 mm, and may be greater than the sum of the central thicknesses of the lenses. Here, the sum of the center spacings between the lenses may mean the sum of the center spacing (CG1) between the first lens (101) and the second lens (102), the center spacing (CG2) between the second lens (102) and the third lens (103), the center spacing (CG3-1) between the third lens (103) and the filter (111), the center spacing (CG3-2) between the filter (111) and the fourth lens (104), the center spacing (CG4) between the fourth lens (104) and the fifth lens (105), and the center spacing (CG5) between the fifth lens (105) and the sixth lens (106).

[0080] The average value of the effective diameter of each lens surface of the optical system (100) can be provided within a range of 20 mm or less, for example, 10 mm to 20 mm. By adjusting the thickness of each lens within the optical system (100), it is possible to prevent degradation of optical performance for temperature changes from -45 to 120 degrees and to optimize thermal compensation.

[0081] In the optical system according to the present embodiment, the angle of view may be in the range of more than 10 degrees, for example, 15 degrees or more, for example, 15±10 degrees. The F number of the optical system or camera module may be 1 or less, for example, in the range of 0.7 to 1 or 0.7 to 0.9. The diagonal length of the image sensor (300) may be 6.041 mm±0.5 mm. In the optical system according to the present embodiment, glass lenses may be laminated to suppress changes in the focus imaging position due to temperature changes, and an aspherical lens may be provided to provide a vehicle lidar device that corrects various aberrations.

[0082] Since this embodiment is an optical system applied to a lidar device, the first lens (101) can be provided with a glass material. This is because glass has the advantage of being scratch-resistant and insensitive to external temperatures compared to plastic materials. To more effectively prevent scratches caused by foreign substances or when placed inside a vehicle, a glass lens is used as the first lens (101). The lidar device can detect the distance to an object, direction, speed, temperature, material distribution, and concentration characteristics while the vehicle is running. Such a lidar device can be used for an advanced driver assistance system (ADAS).

[0083] The optical system (100) according to the present embodiment may further include a reflective member (not shown) for changing the path of light. The reflective member may be implemented as a prism that reflects incident light toward the lenses. Hereinafter, the optical system according to the present embodiment will be described in detail.

[0084]

[0085] An optical system according to this embodiment of the present invention will be described.

[0086] Referring to FIG. 1, the optical system (100) may include a first lens (101) to a sixth lens (106). The first to sixth lenses (101 to 106) may be sequentially arranged along the optical axis (OA) of the optical system (100). Light corresponding to information about an object may pass through the first lens (101) to the third lens (103), the filter (155), the fourth lens (104) to the sixth lens (106), and the cover glass (112) and be incident on the image sensor (300). An aperture (ST) may be arranged around the sensor-side surface of the first lens (101).

[0087] The first lens (101) can have positive (+) or negative (-) refractive power on the optical axis (OA). The first lens (101) can have negative (-) refractive power. The first lens (101) can include a plastic material or a glass material, and can be, for example, a glass material. The first lens (101) made of a glass material can reduce changes in the center position and radius of curvature due to temperature changes according to the surrounding environment, and can protect the incident side surface of the optical system (100). The first lens (101) is made of a glass material that is not injection molded.

[0088] The first surface (S1) on the object side of the first lens (101) with respect to the optical axis may be concave, and the second surface (S2) on the sensor side may be concave. The first lens (101) may have a concave shape on both sides. The first surface (S1) and the second surface (S2) may have spherical surfaces. The first surface (S1) and the second surface (S2) of the first lens (101) may be provided without a critical point from the optical axis (OA) to the end of the effective area, i.e., the edge.

[0089] When the refractive index of the first lens (101) is n1, the condition of 1.8 < n1 or 1.75 < n1 < 2.1 can be satisfied. Since the refractive index (n1) of the first lens (101) is higher than that of other lenses, the radius of curvature of the first surface (S1) of the first lens (101) can be increased, and lens manufacturing can be easy. When the refractive index (n1) of the first lens (101) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (101, 102). In this case, lens manufacturing is not easy, the lens defect rate increases, and this may cause a decrease in yield.

[0090]

[0091] The aperture (STOP) may be arranged around the sensor-side second surface (S2) of the first lens (101). The aperture (STOP) can control the amount of light emitted from the optical system (100). The aperture (STOP) can reduce the TTL within the field of view range, enabling miniaturization of the optical system. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL within the field of view range of 10 to 30 degrees.

[0092]

[0093] The second lens (102) may be positioned between the first lens (101) and the third lens (103). The second lens (102) may have positive (+) or negative (-) refractive power on the optical axis (OA). The second lens (102) may have positive (+) refractive power. The second lens (102) may include a plastic or glass material, and may be provided as a glass material, for example. The second lens (102) is a glass material that is not injection molded. The third surface (S3) and the fourth surface (S4) of the second lens (102) may be spherical.

[0094] The object-side third surface (S3) of the second lens (102) may be convex with respect to the optical axis (OA), and the sensor-side fourth surface (S4) may be convex. The second lens (102) may have a convex shape on both sides. The third surface (S3) and the fourth surface (S4) may be provided without a critical point from the optical axis (OA) to the end of the effective area. When the refractive index of the second lens (102) is n2, the condition of 1.7 < n2 or 1.75 < n2 < 2.1 may be satisfied.

[0095]

[0096] The third lens (103) may be positioned between the second lens (102) and the fourth lens (104). The third lens (103) may have positive (+) or negative (-) refractive power on the optical axis (OA). The third lens (103) may have positive (+) refractive power. The third lens (103) may include a plastic or glass material, and may be provided as a glass material, for example. The third lens (103) is a glass material that is not injection molded. The fifth surface (S5) and the sixth surface (S6) of the third lens (103) may be spherical.

[0097] The object-side fifth surface (S5) of the third lens (103) with respect to the optical axis (OA) may be convex, and the sensor-side sixth surface (S6) may be convex. The third lens (103) may have a convex shape on both sides. The fifth surface (S5) and the sixth surface (S6) may be provided without a critical point from the optical axis (OA) to the end of the effective area. When the refractive index of the third lens (103) is n3, the condition of 1.6 < n3 or 1.7 < n3 < 2.1 may be satisfied.

[0098] A filter (111) may be placed between the third lens (103) and the fourth lens (104). The filter (111) may be a band pass filter that passes a laser beam in the range of 890 nm to 960 nm or 940 nm ±10 nm. The optical filter may pass light having a wavelength corresponding to the laser beam transmitted from the receiving optical system of the lidar device and block light corresponding to the remaining ambient light.

[0099]

[0100] The fourth lens (104) may be arranged between the third lens (103) and the fifth lens (105). The fourth lens (104) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fourth lens (104) may have positive (+) refractive power. The fourth lens (104) may include a plastic or glass material, and may be provided as a glass material, for example. The fourth lens (104) is a glass material that is not injection molded. The seventh surface (S7) and the eighth surface (S8) of the fourth lens (104) may be spherical.

[0101] The seventh surface (S7) on the object side of the fourth lens (104) may be convex with respect to the optical axis (OA), and the eighth surface (S8) on the sensor side may be concave. The seventh surface (S7) on the object side of the fourth lens (104) may be convex with respect to the optical axis, and the eighth surface (S8) on the sensor side may be concave. The fourth lens (104) may have a meniscus shape with a concave sensor side. The fourth lens (104) may have a meniscus shape with a convex object side. The seventh surface (S7) and the eighth surface (S8) may be provided without critical points from the optical axis (OA) to the ends of the effective areas. When the refractive index of the fourth lens (104) is n4, the conditions of 1.4 < n4 or 1.5 < n4 < 1.8 may be satisfied.

[0102]

[0103] The fifth lens (105) may be arranged between the fourth lens (104) and the sixth lens (106). The fifth lens (105) may have positive (+) or negative (-) refractive power on the optical axis (OA). The fifth lens (105) may have positive (+) refractive power. The fifth lens (105) may include a plastic or glass material, and may be provided as a glass material, for example. The fifth lens (105) is a glass material that is not injection molded. The ninth surface (S9) and the tenth surface (S10) of the fifth lens (105) may be spherical.

[0104] The ninth surface (S9) on the object side of the fifth lens (105) may be convex with respect to the optical axis (OA), and the tenth surface (S10) on the sensor side may be concave. The ninth surface (S9) on the object side of the fifth lens (105) may be convex with respect to the optical axis, and the tenth surface (S10) on the sensor side may be concave. The fifth lens (105) may have a meniscus shape with a concave sensor side. The fifth lens (105) may have a meniscus shape with a convex object side. The ninth surface (S9) and the tenth surface (S10) may be provided without a critical point from the optical axis (OA) to the end of the effective area. When the refractive index of the fifth lens (105) is n5, the condition of 1.7 < n5 or 1.8 < n5 < 2.1 may be satisfied.

[0105]

[0106] The sixth lens (106) may be arranged furthest from the object side. The sixth lens (106) may be arranged closest to the sensor side. The sixth lens (106) may have positive (+) or negative (-) refractive power on the optical axis (OA). The sixth lens (106) may have positive (+) refractive power. The third lens (103) may include a plastic or glass material, and may be, for example, a glass material. The third lens (103) may be a glass mold lens having an aspherical surface and made of a glass material. The glass mold lens may be manufactured by placing an optical glass ingot inside a mold having an aspherical shape and through a heating and compression process. The eleventh surface (S11) and the twelfth surface (S12) of the sixth lens (106) may be aspherical surfaces.

[0107] The object-side eleventh surface (S11) of the sixth lens (106) may be convex with respect to the optical axis (OA), and the sensor-side twelfth surface (S12) may be concave. The object-side eleventh surface (S11) of the sixth lens (106) may be convex with respect to the optical axis, and the sensor-side twelfth surface (S12) may be concave. The sixth lens (106) may have a meniscus shape with a concave sensor side. The sixth lens (106) may have a meniscus shape with a convex object side. The eleventh surface (S11) and the twelfth surface (S12) may be provided without critical points from the optical axis (OA) to the ends of the effective areas. When the refractive index of the sixth lens (106) is n6, the conditions of 1.6 < n6 or 1.7 < n6 < 2.1 may be satisfied.

[0108] A cover glass (112) may be placed between the sixth lens (106) positioned closest to the image sensor (300) and the image sensor (300). The cover glass (112) protects the upper portion of the image sensor (300) and may prevent a decrease in the reliability of the image sensor (300). The cover glass (112) may be a protective glass.

[0109] The image sensor (300) can detect light that has sequentially passed through the lenses. The image sensor (300) can include a device capable of detecting incident light, such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

[0110]

[0111] Fig. 2 is an example of lens data of the exemplary optical system of Fig. 1. As shown in Fig. 2, the radius of curvature on the optical axis (OA) of the first to sixth lenses (101-106), the thickness at the center of the lenses, the distance between the centers of the lenses, the refractive index at the d-line, the Abbe's number, and the size of the semi-aperture can be set.

[0112] The center thicknesses of the first to sixth lenses (101-106) are represented by CT1 to CT6, the edge thicknesses at the ends of the effective areas of each lens are represented by ET1 to ET6, and the center gap between two adjacent lenses is represented by CG1 to CG5. Since the filter (111) is placed between the third lens (103) and the fourth lens (104), the center gap between the third lens (103) and the filter (111) is defined as CG3-1, and the center gap between the filter (111) and the fourth lens (104) is defined as CG3-2.

[0113] The first to sixth lenses (101-106) can satisfy the following conditions.

[0114] Condition 1: CT1 < CT6 < CT2 < CT3 < CT4 < CT5

[0115] Condition 2: ET3 < ET6 < ET4 < ET2 < ET5 < ET1

[0116] Condition 3: CG3-1 = CG3-2 = CG4 < CG1 < CG5 < CG2

[0117]

[0118] The central thickness (CT5) of the fifth lens (105) is the largest among the lenses, and the central thickness (CT1) of the first lens (101) is the smallest among the lenses. The maximum central thickness may be at least twice, for example at least 2.5 times, the minimum central thickness, and the difference between the maximum central thickness and the minimum central thickness may be at least 4 mm.

[0119] When describing the center spacing (CG) between adjacent lenses, the center spacing (CG2) between the second lens (102) and the third lens (103) may be maximum, and the center spacing (CG3-1) between the third lens (103) and the filter (111), the center spacing (CG3-2) between the filter (111) and the fourth lens (104), and the center spacing (CG4) between the fourth lens (104) and the fifth lens (105) may be minimum. Here, the difference between the maximum center spacing and the minimum center spacing may be 6 mm or more, for example, in the range of 8 mm to 10 mm.

[0120]

[0121] Regarding the effective diameter, the lens having the maximum effective diameter may be the fourth lens (104). The lens having the maximum effective diameter may be a spherical lens made of glass. The lens surface having the maximum effective diameter may be the seventh surface (S7) of the fourth lens (104). The lens having the minimum effective diameter may be the sixth lens (106) arranged closest to the sensor side. The lens surface having the minimum effective diameter may be the twelfth surface (S12) of the sixth lens (106).

[0122] The effective diameter of the first lens (101) may be smaller than the effective diameter of the second lens (102). The effective diameter of the second lens (102) may be smaller than the effective diameter of the third lens (103). The effective diameter of the third lens (103) may be smaller than the effective diameter of the fourth lens (104). The effective diameter of the fourth lens (104) may be larger than the effective diameter of the fifth lens (105). The effective diameter of the fifth lens (105) may be larger than the effective diameter of the sixth lens (106).

[0123] The absolute value of the curvature radius of the object-side surface of the first lens (101) and the absolute value of the curvature radius of the sensor-side surface may be the same. The curvature radius of the object-side surface of the second lens (102) and the curvature radius of the sensor-side surface may be the same. The curvature radius of the object-side surface of the third lens (103) and the curvature radius of the sensor-side surface may be the same. Through this, since the shape and curvature radius of the object-side surface and the sensor-side surface of the lenses are the same, lens assembly is easy and the yield can be increased.

[0124] The second lens (102) to the sixth lens (106) may all have positive (+) refractive power. The absolute values ​​of the focal lengths of the first to sixth lenses (101 to 106) may increase from the object side to the sensor side. The absolute value of the focal length of the first lens (101) may be the smallest, and the absolute value of the focal length of the sixth lens (106) may be the largest. Accordingly, the optical system may have improved MTF characteristics, aberration control characteristics, etc. in the set angle of view range, and may have good optical performance.

[0125] FIG. 3 shows the effective focal length (F), TTL (Total track length) (mm), BFL (Back focal length), entrance pupil (EPD), ImgH, effective diameter (CA), sum of center thicknesses of each lens (ΣCT), sum of center spacings between adjacent lenses (ΣCG), edge thickness of each lens, sum of edge thicknesses of each lens (ΣET), TTL (mm), sum of Abbe numbers (ΣAbbe), sum of refractive indices (ΣIndex), TD (mm), which is the optical axis distance from the first surface (S1) to the twelfth surface (S12), SD (mm), which is the optical axis distance from the stop (STOP) to the twelfth surface (S12), angle of view (FOV), edge thickness (ET), F number, etc. of the optical system (100) of the present embodiment.

[0126] As shown in Fig. 4, among the lenses of the present embodiment, the lens surface of the sixth lens (106) may include an aspherical surface having a 30th-order aspherical surface coefficient. For example, the object-side surface and the light source-side surface of the sixth lens (106) may be lens surfaces having a 30th-order aspherical surface coefficient. As described above, an aspherical surface having a 30th-order aspherical surface coefficient (a value other than “0”) can significantly change the aspherical shape of the periphery, and thus can effectively correct the optical performance of the periphery of the field of view (FOV).

[0127] Fig. 6 is a graph showing the diffraction MTF (Modulation Transfer Function) at room temperature in the optical system of Fig. 1, and is a graph showing the modulation ratio according to the spatial frequency. The x-axis represents the distance from the center to the edge of the lens, and the y-axis represents the resolution of the lens as a value between 0 and 1. As shown in Fig. 4, it can be seen that the curve of the MTF graph in the first embodiment of the present invention is close to 1 in the center region of the lens, indicating good optical performance.

[0128]

[0129] The optical system (100) according to the present embodiment can satisfy at least one or two or more of the mathematical equations described below. Accordingly, the optical system (100) according to the present embodiment can have improved optical characteristics. For example, when the optical system (100) satisfies at least one mathematical equation, the optical system (100) can effectively control aberration characteristics such as chromatic aberration and distortion aberration, and can have good optical performance even in the center and periphery of the field of view (FOV). In addition, the optical system (100) can have improved resolution. In addition, the thickness of the lens on the optical axis (OA) described in the mathematical equations and the spacing between adjacent lenses on the optical axis (OA) may refer to the above-described embodiment.

[0130]

[0131] [Mathematical Formula 1]

[0132] 0.1 < F / TTL < 0.5

[0133] Mathematical expression 1 can set the overall focal length (F) and overall optical axis length (TTL) of the optical system (100). Accordingly, an optical system for a driver assistance system can be provided. Mathematical expression 1 can preferably satisfy 0.1 < F / TTL < 0.3 in the present embodiment. When Mathematical expression 1 is satisfied, the optical system (100) can have an appropriate focal length in the set TTL range, and provides an optical system that can form an image while maintaining an appropriate focal length even when the temperature changes from low to high temperatures. When it is less than the lower limit of Mathematical expression 1, the refractive power of the lenses needs to be increased, making it difficult to correct spherical aberration or distortion aberration, and when it exceeds the upper limit of Mathematical expression 1, the effective diameter or TTL of the lenses becomes long, which may cause a problem of the imaging lens system becoming larger.

[0134]

[0135] [Equation 2]

[0136] 5 < TTL / ImgH < 10

[0137] Mathematical expression 2 can set the total optical axis length (TTL) of the optical system and the maximum diagonal length (ImgH) of the image sensor (300). When Mathematical expression 2 is satisfied, the optical system (100) can have TTL for application to the vehicle image sensor (300), thereby providing more improved image quality. When it is less than the lower limit of Mathematical expression 2, the refractive power of the lenses needs to be increased, making it difficult to correct spherical aberration or distortion aberration, and when it exceeds the upper limit of Mathematical expression 2, the effective diameter or TTL of the lenses becomes long, which may cause a problem of the imaging lens system becoming larger. Mathematical expression 2 can preferably satisfy 7 < TTL / ImgH < 9 in the present embodiment.

[0138]

[0139] [Equation 3]

[0140] 1 < ┃F1┃ / F < 3

[0141] In mathematical expression 3, F1 is the focal length of the first lens (101), and F is the effective focal length of the optical system. When mathematical expression 3 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. When it is less than the lower limit of mathematical expression 3, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 3, the influence of the first lens (101) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem in that correction of spherical aberration or distortion aberration becomes difficult. In the present embodiment, mathematical expression 3 may preferably satisfy 1 < ┃F1┃ / F < 1.5.

[0142]

[0143] [Equation 4]

[0144] 1 < F2 / F < 5

[0145] In mathematical expression 4, F2 is the focal length of the second lens (102), and F is the effective focal length of the optical system. When mathematical expression 4 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and a vehicle optical system can be provided. When it is less than the lower limit of mathematical expression 4, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 4, the influence of the second lens (102) arranged adjacent to the aperture (STOP) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem in that correction of spherical aberration or distortion aberration becomes difficult. In the present embodiment, mathematical expression 4 can preferably satisfy 3 < F2 / F < 4.

[0146]

[0147] [Equation 5]

[0148] 3 < F6 / F < 7

[0149] In mathematical expression 5, F6 is the focal length of the sixth lens (106), and F is the effective focal length of the optical system. When mathematical expression 5 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. When it is less than the lower limit of mathematical expression 5, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 5, the influence of the sixth lens (106) arranged closest to the image sensor (300) becomes small in the entire optical system, and the refractive power of the lenses needs to be increased, which causes a problem in that correction of spherical aberration or distortion aberration becomes difficult. In the present embodiment, mathematical expression 5 may preferably satisfy 5 < F6 / F < 6.

[0150]

[0151] [Equation 6]

[0152] 0.1 < F / EPD < 1

[0153] Mathematical expression 6 can set the overall focal length (F) of the optical system (100) and the size of the entrance pupil diameter (effective aperture, EPD). When mathematical expression 6 is satisfied, an image with a brightness suitable for shooting can be provided, and a large amount of light can be received by the image sensor. In the present embodiment, mathematical expression 6 can preferably satisfy 0.7 < F / EPD < 0.9.

[0154]

[0155] [Equation 7]

[0156] 2 < F3 / F < 5

[0157] In mathematical expression 7, F3 is the focal length of the third lens (103), and F is the effective focal length of the optical system. When mathematical expression 7 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. When it is less than the lower limit of mathematical expression 7, the effective diameter or TTL of the lenses may become long, which may cause a problem in that the imaging lens system becomes large. When it is more than the upper limit of mathematical expression 7, the influence of the third lens (103) in the entire optical system becomes small, and the refractive power of the lenses needs to be increased, which causes a problem in that correction of spherical aberration or distortion aberration becomes difficult. In the present embodiment, mathematical expression 7 can preferably satisfy 3 < F3 / F < 4.5.

[0158]

[0159] [Equation 8]

[0160] 3 < F5 / F < 6

[0161] In mathematical expression 8, F5 is the focal length of the fifth lens (105), and F is the effective focal length of the optical system. When mathematical expression 8 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. When it is less than the lower limit of mathematical expression 8, the effective diameter or TTL of the lenses may become longer, which may cause a problem in that the imaging lens system becomes larger. When it is more than the upper limit of mathematical expression 8, there is a problem in that it is difficult to correct spherical aberration or distortion aberration. In the present embodiment, mathematical expression 8 can preferably satisfy 4 < F5 / F < 5.

[0162]

[0163] [Equation 9]

[0164] 0.1 < CG1 / CG2 < 0.5

[0165] In mathematical expression 9, CG1 denotes the center spacing between the first lens (101) and the second lens (102), and CG2 denotes the center spacing between the second lens (102) and the third lens (103). When mathematical expression 9 is satisfied, the center spacing between the second lens (102) and the third lens (103), which is the maximum center spacing between the lenses, can be appropriately designed within the optical system (100) to suppress an increase in the size of the second lens (102). In the present embodiment, mathematical expression 9 can preferably satisfy 0.1 < CG1 / CG2 < 0.3.

[0166]

[0167] [Equation 10]

[0168] 0.5 < CA_L1 / CA_L2 < 1

[0169] Mathematical expression 10 can set the relationship between the size of the effective diameter (CA_L1) of the first lens (101) and the size of the effective diameter (CA_L2) of the second lens (102). When Mathematical expression 10 is satisfied, the effective diameters of the first lens (101) and the second lens (102) arranged adjacent to the aperture (STOP) can be appropriately designed to appropriately set the angle of view of the light passing through the aperture (STOP). When it is less than the lower limit of Mathematical expression 10, the effective diameter of the lens arranged in the optical system (100) becomes large, which causes a problem in that the TTL becomes long. When it exceeds the upper limit of Mathematical expression 10, there is a problem in that the angle of view becomes excessively large compared to that satisfied by the optical system (100). In the present embodiment, Mathematical expression 10 can preferably satisfy 0.7 < CA_L1 / CA_L2 < 0.9.

[0170]

[0171] [Equation 11]

[0172] 0.5 < CA_L3 / CA_L4 < 1.5

[0173] Mathematical expression 11 can set the relationship between the size of the effective diameter (CA_L3) of the third lens (103) and the size of the effective diameter (CA_L4) of the fourth lens (104). When Mathematical expression 11 is satisfied, the effective diameters of the third lens (103) and the fourth lens (104) arranged adjacent to the filter (111) can be appropriately designed to appropriately set the angle of view of the light passing through the filter (111). When it is less than the lower limit of Mathematical expression 11, the effective diameter of the lens arranged in the optical system (100) becomes large, which causes a problem in that the TTL becomes long. When it exceeds the upper limit of Mathematical expression 11, there is a problem in that the angle of view becomes excessively large compared to that satisfied by the optical system (100). In the present embodiment, Mathematical expression 11 can preferably satisfy 0.8 < CA_L3 / CA_L4 < 1.1.

[0174]

[0175] [Equation 12]

[0176] 1.8 < n1 < 1.9

[0177] In mathematical expression 12, n1 is the refractive index of the first lens (101) at the d-line. By setting the refractive index of the first lens (101) high in mathematical expression 12, the factors affecting the reduction of the third-order aberration (Seidel aberration) of the optical system can be adjusted, and the aberration that may occur as the TTL becomes somewhat longer can be reduced. If it is designed to be lower than the lower limit of mathematical expression 12, the performance of reducing aberration can be obtained, and the refractive power of the first lens (101) may be weakened, making it difficult to collect light efficiently, which may deteriorate the performance of the optical system. If it is designed to be higher than the upper limit of mathematical expression 12, there is a disadvantage in that it becomes difficult to obtain materials. In addition, if the refractive index of the first lens (101) is designed to be lower than the lower limit of mathematical expression 12, the radius of curvature of each lens may be increased in order to increase the refractive power of the lenses in the optical system (100). In this embodiment, mathematical expression 12 preferably satisfies 1.8 < n1 < 1.85.

[0178]

[0179] [Equation 13]

[0180] 1 < n1 / n2 < 1.5

[0181] In mathematical expression 13, n1 is the refractive index of the first lens (101) at the d-line, and n2 is the refractive index of the second lens (102) at the d-line. In mathematical expression 13, by reducing the difference in the refractive index of the first lens (101) and the second lens (102), the reduction in color dispersion caused by lenses made of glass can be prevented. Preferably, in this embodiment, mathematical expression 13 can satisfy 1 < n1 / n2 < 1.2.

[0182]

[0183] [Equation 14]

[0184] 1 < n3 / n4 < 1.5

[0185] In mathematical expression 14, n3 is the refractive index of the third lens (103) at the d-line, and n4 is the refractive index of the fourth lens (104) at the d-line. In mathematical expression 14, the difference in the refractive index of the third lens (103) and the fourth lens (104) placed adjacent to the filter (111) is reduced, thereby preventing a decrease in the color dispersion of light passing through the filter (111). Preferably, in the present embodiment, mathematical expression 14 can satisfy 1 < n3 / n4 < 1.2.

[0186]

[0187] [Equation 15]

[0188] 0.5 < CT_Max / CG_Max < 1

[0189] In mathematical expression 15, the maximum central thickness (CT_Max) among the lenses and the maximum gap (CG_Max) between adjacent lenses can be set. When mathematical expression 15 is satisfied, the optical system can have good optical performance at the focal length of the set angle of view and can reduce the TTL. In the present embodiment, mathematical expression 15 can preferably satisfy 0.6 < CT_Max / CG_Max < 0.9.

[0190]

[0191] [Equation 16]

[0192] 1 < ∑CT / ∑CG < 3

[0193] In Equation 16, ΣCT is the sum of the central thicknesses of the lenses, and ΣCG is the sum of the spacings between adjacent lenses. When Equation 16 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view, and can reduce the TTL. Equation 16 can preferably satisfy 1.5 < ΣCT / ΣCG < 2.5 in the present embodiment.

[0194]

[0195] [Equation 17]

[0196] 8 < ∑Index < 12

[0197] In mathematical expression 17, ΣIndex means the sum of the refractive indices at the d-line of each of the plurality of lenses. When mathematical expression 17 is satisfied, TTL can be controlled in an optical system (100) in which aspherical lenses and spherical material lenses are mixed. In addition, when the number of spherical material lenses is greater than the number of aspherical material lenses, the sum of TTL and refractive indices can be set. In the present embodiment, mathematical expression 17 can preferably satisfy 9 < ΣIndex < 11.

[0198]

[0199] [Equation 18]

[0200] 15 < ∑Abbe / ∑Index < 25

[0201] In mathematical expression 18, ΣAbbe means the sum of the Abbe's numbers of each of the plurality of lenses, and ΣIndex means the sum of the refractive indices at the d-line of each of the plurality of lenses. When mathematical expression 18 is satisfied, the optical system (100) can have improved aberration characteristics and resolution. By setting the sum of the Abbe's numbers and the sum of the refractive indices of the lenses in mathematical expression 18, the optical characteristics can be controlled. In the present embodiment, mathematical expression 18 can preferably satisfy 17 < ΣAbbe / ΣIndex < 20.

[0202]

[0203] [Equation 19]

[0204] 1 < ΣCT / ΣET < 2

[0205] In mathematical expression 19, ΣCT is the sum of the central thicknesses of the lenses, and ΣET is the sum of the edge thicknesses, i.e., the ends of the effective areas of the lenses. When mathematical expression 19 is satisfied, the optical system can have good optical performance at the focal length at the set angle of view, and can reduce the TTL. In the present embodiment, mathematical expression 19 preferably satisfies 1.2 < ΣCT / ΣET < 1.5.

[0206]

[0207] [Equation 20]

[0208] 1 < CA_Max / CA_Aver < 2

[0209] In mathematical expression 20, CA_Max represents the maximum effective diameter among the object-side and sensor-side faces of the lenses, and CA_Aver represents the average of the effective diameters of the object-side and sensor-side faces of the lenses. When mathematical expression 20 is satisfied, the optical system can be configured as a slim and compact optical system while maintaining optical performance. In the present embodiment, mathematical expression 20 can preferably satisfy 1.2 < CA_Max / CA_Aver < 1.5.

[0210]

[0211] [Equation 21]

[0212] 0.1 < CA_Min / CA_Aver < 1

[0213] In mathematical expression 21, CA_Min represents the minimum effective diameter among the object-side and sensor-side surfaces of the lenses, and CA_Aver represents the average of the effective diameters of the object-side and sensor-side surfaces of the lenses. When mathematical expression 21 is satisfied, the optical system can be configured as a slim and compact optical system while maintaining optical performance. In the present embodiment, mathematical expression 21 can preferably satisfy 0.4 < CA_Min / CA_Aver < 0.7.

[0214]

[0215] [Equation 22]

[0216] 3 < CA_Max / ImgH < 5

[0217] Mathematical expression 22 can be set by the maximum effective diameter (CA_Max) and the maximum diagonal length (ImgH) of the image sensor (300). When mathematical expression 22 is satisfied, the optical system can maintain good optical performance and can be configured as a slim and compact optical system. In the present embodiment, mathematical expression 22 preferably satisfies 3.5 < CA_Max / ImgH < 4.5.

[0218]

[0219] [Equation 23]

[0220] 50 < TTL < 60

[0221] In mathematical expression 23, TTL (Total track length) means the distance (mm) on the optical axis (OA) from the center of the first surface (S1) of the first lens (101) to the upper surface of the image sensor (300). When mathematical expression 23 is satisfied, a suitable vehicle optical system can be provided. In the present embodiment, mathematical expression 23 can preferably satisfy 50 < TTL < 55.

[0222]

[0223] [Equation 24]

[0224] 6 < ImgH < 7

[0225] Mathematical expression 24 can set the maximum diagonal size (ImgH) of the image sensor (300) and provide an optical system having a vehicle sensor size. Mathematical expression 24 can preferably satisfy 6.1 < ImgH < 6.5 in the present embodiment.

[0226]

[0227] [Equation 25]

[0228] 1 < BFL < 3

[0229] In mathematical expression 25, BFL is the optical axis distance from the image sensor (300) to the center of the sensor side of the last lens. When mathematical expression 25 is satisfied, the installation space of the filter (400) and the cover glass can be secured, the assembling of the components can be improved through the gap between the image sensor (300) and the last lens, and the joining reliability can be improved. When the BFL is less than the range of mathematical expression 25, some of the light going to the image sensor may not be transmitted to the image sensor, which may cause a decrease in resolution. When the BFL exceeds the range of mathematical expression 25, stray light may be introduced, which may deteriorate the aberration characteristics of the optical system. In the present embodiment, mathematical expression 25 may preferably satisfy 1.5 < BFL < 2.5.

[0230]

[0231] [Equation 26]

[0232] 8 < F < 12

[0233] Mathematical expression 26 can set the overall focal length (F) to suit the vehicle optical system. Mathematical expression 26 can preferably satisfy 9 < F < 11 in the present embodiment.

[0234]

[0235] [Equation 27]

[0236] 10 < FOV < 20

[0237] In mathematical expression 27, FOV (Field of view) refers to the angle of view (Degree) of the optical system (100), and a narrow-angle optical system for a vehicle having an angle of view (F0V) of less than 20 degrees can be provided. In the present embodiment, FOV can preferably satisfy 15 < FOV < 18.

[0238]

[0239] [Equation 28]

[0240] 1.5 < TTL / CA_Max < 2.5

[0241] In mathematical expression 28, CA_max means the largest effective diameter (mm) among the object-side and light-source-side surfaces of a plurality of lenses, and TTL (Total track length) means the distance (mm) from the vertex of the first surface (S1) of the first lens (101) to the upper surface of the image sensor (300) on the optical axis (OA). Mathematical expression 28 sets the relationship between the total optical axis length of the optical system and the maximum effective diameter, thereby providing an improved vehicle optical system. Mathematical expression 28 can preferably satisfy 1.8 < TTL / CA_Max < 2.2 in the present embodiment.

[0242]

[0243] [Equation 29]

[0244] 0.1 < BFL / ImgH < 0.5

[0245] Mathematical expression 29 can set the optical axis distance (BFL) between the image sensor (300) and the last lens and the maximum diagonal length (ImgH) of the image sensor (300). When Mathematical expression 29 is satisfied, the optical system (100) can secure the BFL (Back focal length) for applying the size of the vehicle image sensor (300), can set the distance between the last lens and the image sensor (300), and can have good optical characteristics in the field of view (FOV). Mathematical expression 29 can preferably satisfy 0.2 < BFL / ImgH < 0.4 in the present embodiment.

[0246]

[0247] [Equation 30]

[0248] 22 < TTL / BFL < 27

[0249] Mathematical expression 30 can set the total optical axis length (TTL) of the optical system and the optical axis spacing (BFL) between the image sensor (300) and the last lens. When mathematical expression 30 is satisfied, the optical system (100) can secure BFL. In the present embodiment, mathematical expression 30 can preferably satisfy 24 < TTL / BFL < 26.

[0250]

[0251] [Equation 31]

[0252] 4 < F / BFL < 6

[0253] Mathematical expression 31 can set the overall focal length (F) of the optical system (100) and the optical axis distance (BFL) between the image sensor (300) and the last lens. When Mathematical expression 31 is satisfied, the optical system (100) can have a set angle of view and an appropriate focal length, and an optical system for a vehicle can be provided. In addition, the optical system (100) can minimize the distance between the last lens and the image sensor (300), and thus can have good optical characteristics in the angle of view (FOV). Mathematical expression 31 can preferably satisfy 5 < F / BFL < 5.5 in the present embodiment.

[0254]

[0255] [Equation 32]

[0256] 1 < F / ImgH < 2

[0257] Mathematical expression 32 can set the total focal length (F, mm) of the optical system (100) and the maximum diagonal length (ImgH) of the image sensor (300). When mathematical expression 32 is satisfied, the vehicle image sensor (300) can have improved aberration characteristics in terms of size. In the present embodiment, mathematical expression 32 can preferably satisfy 1.5 < F / ImgH < 1.8.

[0258]

[0259] [Equation 33]

[0260] 0.5 < Fno < 1

[0261] Mathematical expression 33 can establish the relationship between the angle of view and Fno (F number) of the optical system (100). Mathematical expression 33 can preferably satisfy 0.7 < Fno < 0.9 in the present embodiment. Here, Fno is provided to be 1 or less, so as to provide a bright image.

[0262]

[0263] [Equation 34]

[0264]

[0265] In mathematical expression 34, Z can represent Sag, which is the distance from any position on the aspherical surface to the vertex of the aspherical surface in the direction of the optical axis. Y can represent the distance from any position on the aspherical surface to the optical axis in the direction perpendicular to the optical axis. c can represent the curvature of the lens, and K can represent the conic constant. In addition, A, B, C, D, E, and F can represent aspheric constants.

[0266]

[0267] The optical system (100) according to the present embodiment can satisfy at least one or two or more mathematical equations from mathematical equations 1 to 34. In this case, the optical system (100) can have improved optical characteristics. Specifically, when the optical system (100) satisfies at least one of mathematical equations 1 to 34, the optical system (100) can have improved resolution and improve aberration and distortion characteristics. In addition, the optical system (100) can compensate for the deterioration of optical characteristics due to temperature change, and can minimize the gap between the last lens and the light source (300), thereby having good optical performance within the field of view (FOV).

[0268]

[0269] FIG. 5 shows the result values ​​for the mathematical expressions 1 to 33 described above in the optical system (100) according to the present embodiment. Referring to FIG. 5, it can be seen that the optical system (100) satisfies at least one, two or more, or three or more of the mathematical expressions 1 to 33. In detail, it can be seen that the optical system (100) according to the present embodiment satisfies all of the mathematical expressions 1 to 33. Accordingly, the optical system (100) can have good optical performance within the field of view (FOV) and can have excellent optical characteristics.

[0270]

[0271] Fig. 7 is a block diagram of a sensor system having a receiving optical system according to the present embodiment. Referring to Fig. 7, the sensor device includes a control unit (10), a light source driving unit (20), a receiving optical system (30), the receiving optical system (50) disclosed above, and a signal processing unit (60).

[0272] The control unit (10) controls the transmission and reception of signals, and can be linked to devices related to communication services such as autonomous driving modules, artificial intelligence modules, drones, robots, augmented reality devices, virtual phenomenon devices, and 5G and 6G based on the transmitted / received signals.

[0273] The light source driving unit (20) supplies power to and drives the light source included in the receiving optical system (30). The light source generates laser light in the form of a line light source or a point light source. The light source driving unit (20) can adjust or vary the driving current supplied to the light source according to driving environment information. The driving environment information may include terrain information of the driving section, traffic congestion information, weather, etc.

[0274] The wavelength of the laser light generated from the light source may be in the range of 890 nm to 960 nm or 940 nm ±10 nm. The laser light source may be implemented as an InGaAs / GaAs-based semiconductor diode laser and may emit high-power laser light. The light source may include a single emitter and / or multiple emitters.

[0275] The receiving optical system (30) transmits laser light generated from a light source to an object (40), and the light reflected from the object (40) is received by the receiving optical system (50). The receiving optical system (50) may be composed of a plurality of light sensors, and the light sensors convert the received light into an electrical signal using a photodiode. That is, the image sensors are arranged in a matrix type to convert the light received from an object scanned in each of the horizontal and vertical directions into an electric current.

[0276] The signal processing unit (60) converts the output of the receiving optical system (50) into a voltage, amplifies it, and then converts the amplified signal into a digital signal using an analog-to-digital converter. The signal processing unit (60) analyzes the digital data using a TOF (Time of Flight) algorithm or a phase-shift algorithm to detect the distance to the object (40) and the shape of the object.

[0277] The control unit (10) can receive vehicle speed information and road condition information through a control unit (ECU) or a network. The control unit (10) can receive driving environment information through a network. The driving environment information can include terrain information of the driving section, traffic congestion information, weather, etc. The control unit (10) can adjust the gain based on one or more of the vehicle speed, the road surface condition of the road on which the vehicle is driving, and the driving environment information, and can provide sensor data including the distance to an object and shape information of the object to the free driving device.

[0278]

[0279] FIG. 8 is a cross-sectional view showing a transmission optical system according to one embodiment of the sensor system of FIG. 9, and it can be confirmed that it has a shape symmetrical to the transmission optical system according to the present embodiment of FIG. 1.

[0280] Referring to FIG. 8, the optical system (200) may include a seventh lens (201) to a twelfth lens (206). The seventh to twelfth lenses (201 to 206) may be sequentially arranged along the optical axis (OA) of the optical system (200). Light corresponding to object information may pass through the seventh lens (201) to the ninth lens (203), the filter (211), the tenth lens (204) to the twelfth lens (206), and the cover glass (212) and be incident on the light source (400). An aperture (ST) may be arranged around the periphery of the light source-side surface of the seventh lens (201).

[0281] The seventh lens (201) may have positive (+) or negative (-) refractive power on the optical axis (OA). The seventh lens (201) may have negative (-) refractive power. The seventh lens (201) may include a plastic material or a glass material, and may be, for example, a glass material. The seventh lens (201) made of a glass material can reduce changes in the center position and radius of curvature due to temperature changes in the surrounding environment, and can protect the incident surface of the optical system (200). The seventh lens (201) is made of a glass material that is not injection molded.

[0282] The 13th surface (S21) on the object side of the seventh lens (201) with respect to the optical axis may be concave, and the 14th surface (S22) on the light source side may be concave. The seventh lens (201) may have a shape in which both sides are concave. The 13th surface (S21) and the 14th surface (S22) may have spherical surfaces. The 13th surface (S21) and the 14th surface (S22) of the seventh lens (201) may be provided without a critical point from the optical axis (OA) to the end of the effective area, i.e., the edge.

[0283] When the refractive index of the seventh lens (201) is n7, the conditions of 1.8 < n7 or 1.75 < n7 < 2.1 can be satisfied. Since the refractive index (n7) of the seventh lens (201) is higher than that of other lenses, the radius of curvature of the 13th surface (S21) of the seventh lens (201) can be increased, and lens manufacturing can be facilitated. When the refractive index (n7) of the seventh lens (201) is smaller than the condition, the lens surface must be formed to be sharply concave or convex in order to increase the refractive power of the first and second lenses (101, 102). In this case, lens manufacturing is not easy, the lens defect rate increases, and this may cause a decrease in yield.

[0284] The stop (STOP) may be arranged around the 14th surface (S22) on the light source side of the seventh lens (201). The stop (STOP) can control the amount of light emitted from the optical system (200). The stop (STOP) can reduce the TTL within the field of view range, and the optical system can be miniaturized. Accordingly, a decrease in the yield by weight of the optical system can be prevented, and production efficiency can be improved. In addition, the optical system can be miniaturized by reducing the TTL within the field of view range of 10 to 30 degrees.

[0285]

[0286] The eighth lens (202) may be positioned between the seventh lens (201) and the ninth lens (203). The eighth lens (202) may have positive (+) or negative (-) refractive power on the optical axis (OA). The eighth lens (202) may have positive (+) refractive power. The eighth lens (202) may include a plastic or glass material, and may be provided as a glass material, for example. The eighth lens (202) is a glass material that is not injection molded. The fifteenth surface (S23) and the sixteenth surface (S24) of the eighth lens (202) may be spherical.

[0287] The object-side 15th surface (S23) of the eighth lens (202) with respect to the optical axis (OA) may be convex, and the light source-side 16th surface (S24) may be convex. The eighth lens (202) may have a convex shape on both sides. The 15th surface (S23) and the 16th surface (S24) may be provided without a critical point from the optical axis (OA) to the end of the effective area. When the refractive index of the eighth lens (202) is n8, the condition of 1.7 < n8 or 1.75 < n8 < 2.1 may be satisfied.

[0288]

[0289] The ninth lens (203) may be arranged between the eighth lens (202) and the tenth lens (204). The ninth lens (203) may have positive (+) or negative (-) refractive power on the optical axis (OA). The ninth lens (203) may have positive (+) refractive power. The ninth lens (203) may include a plastic or glass material, and may be provided as a glass material, for example. The ninth lens (203) is a glass material that is not injection molded. The seventeenth surface (S25) and the eighteenth surface (S26) of the ninth lens (203) may be spherical.

[0290] The object-side 17th surface (S25) of the ninth lens (203) with respect to the optical axis (OA) may be convex, and the light source-side 18th surface (S26) may be convex. The ninth lens (203) may have a convex shape on both sides. The 17th surface (S25) and the 18th surface (S26) may be provided without a critical point from the optical axis (OA) to the end of the effective area. When the refractive index of the ninth lens (203) is n9, the condition of 1.6 < n9 or 1.7 < n9 < 2.1 may be satisfied.

[0291] A filter (211) may be placed between the ninth lens (203) and the tenth lens (204). The filter (211) may be a band pass filter that passes a laser beam in the range of 890 nm to 960 nm or 940 nm ±10 nm. The optical filter may pass light having a wavelength corresponding to the laser beam transmitted from the transmission optical system of the lidar device and block light corresponding to the remaining ambient light.

[0292]

[0293] The tenth lens (204) may be arranged between the ninth lens (203) and the eleventh lens (205). The tenth lens (204) may have positive (+) or negative (-) refractive power on the optical axis (OA). The tenth lens (204) may have positive (+) refractive power. The tenth lens (204) may include a plastic or glass material, and may be provided as a glass material, for example. The tenth lens (204) is a glass material that is not injection molded. The nineteenth surface (S27) and the twentieth surface (S28) of the tenth lens (204) may be spherical.

[0294] The object-side 19th surface (S27) of the 10th lens (204) with respect to the optical axis (OA) may be convex, and the light-source-side 20th surface (S28) may be concave. The object-side 19th surface (S27) of the 10th lens (204) with respect to the optical axis may be convex, and the light-source-side 20th surface (S28) may be concave. The 10th lens (204) may have a meniscus shape with a concave light-source side. The 10th lens (204) may have a meniscus shape with a convex object side. The 19th surface (S27) and the 20th surface (S28) may be provided without critical points from the optical axis (OA) to the ends of the effective areas. When the refractive index of the 10th lens (204) is n10, the conditions of 1.4 < n10 or 1.5 < n10 < 1.8 may be satisfied.

[0295]

[0296] The eleventh lens (205) may be arranged between the tenth lens (204) and the twelfth lens (206). The eleventh lens (205) may have positive (+) or negative (-) refractive power on the optical axis (OA). The eleventh lens (205) may have positive (+) refractive power. The eleventh lens (205) may include a plastic or glass material, and may be provided as a glass material, for example. The eleventh lens (205) is a glass material that is not injection molded. The twenty-first surface (S29) and the twenty-second surface (S30) of the eleventh lens (205) may be spherical.

[0297] The object-side 21st surface (S29) of the 11th lens (205) may be convex with respect to the optical axis (OA), and the light-source-side 22nd surface (S30) may be concave. The object-side 21st surface (S29) of the 11th lens (205) may be convex with respect to the optical axis, and the light-source-side 22nd surface (S30) may be concave. The 11th lens (205) may have a concave meniscus shape on the light-source side. The 11th lens (205) may have a convex meniscus shape on the object side. The 21st surface (S29) and the 22nd surface (S30) may be provided without critical points from the optical axis (OA) to the ends of the effective areas. When the refractive index of the 11th lens (205) is n11, the conditions of 1.7 < n11 or 1.8 < n11 < 2.1 may be satisfied.

[0298]

[0299] The twelfth lens (206) may be arranged furthest from the object side. The twelfth lens (206) may be arranged closest to the light source side. The twelfth lens (206) may have positive (+) or negative (-) refractive power on the optical axis (OA). The twelfth lens (206) may have positive (+) refractive power. The ninth lens (203) may include a plastic or glass material, and may be, for example, a glass material. The ninth lens (203) may be a glass mold lens having an aspherical surface and made of a glass material. The glass mold lens may be manufactured by placing an optical glass ingot inside a mold having an aspherical shape and through a heating and compression process. The twenty-third surface (S31) and the twenty-fourth surface (S32) of the twelfth lens (206) may be aspherical surfaces.

[0300] The object-side 23rd surface (S31) of the 12th lens (206) may be convex with respect to the optical axis (OA), and the light-source-side 24th surface (S32) may be concave. The object-side 23rd surface (S31) of the 12th lens (206) may be convex with respect to the optical axis, and the light-source-side 24th surface (S32) may be concave. The 12th lens (206) may have a meniscus shape in which the light-source side is concave. The 12th lens (206) may have a meniscus shape in which the object side is convex. The 23rd surface (S31) and the 24th surface (S32) may be provided without critical points from the optical axis (OA) to the ends of the effective areas. When the refractive index of the 12th lens (206) is n12, the conditions of 1.6 < n12 or 1.7 < n12 < 2.1 may be satisfied.

[0301] A cover glass (212) may be placed between the light source (400) and the sixth lens (106) that is positioned closest to the light source (400). The cover glass (212) protects the upper portion of the light source (400) and may prevent a decrease in the reliability of the light source (400). The cover glass (212) may be a protective glass.

[0302] The optical system (200) or sensor system may include a light source (400). The light source (400) generates laser light with a wavelength ranging from 890 nm to 960 nm or 940 nm ±10 nm. The light source (400) may be implemented with an InGaAs / GaAs-based semiconductor diode laser and may emit high-power laser light. The light source (400) may include a single emitter and / or multiple emitters. The light source (400) generates laser light in the form of a line light source or a point light source. Here, the length (LsH) of the light source (400) is a maximum diagonal length, and the effective diameters of the seventh to twelfth lenses (201 to 206) may be greater than the length (LsH) of the light source (400).

[0303] The shape of each lens surface of the first to sixth lenses (101 to 106) may be symmetrical to the shape of each lens surface of the seventh to twelfth lenses (201 to 206). Accordingly, the reception efficiency of the laser light emitted from the transmitting optical system (200) after being reflected by an object may be increased by the receiving optical system (100).

[0304]

[0305] FIG. 9 is a drawing showing an example of measuring an object in a vehicle having a sensor system of the invention, and FIG. 10 is a drawing showing an example of surrounding surveillance in a vehicle having a sensor system of the invention.

[0306] Referring to FIGS. 9 and 10, a vehicle (502) having a sensor system includes a receiving optical system that projects laser light (501) generated by a light source toward a target scene, and a receiving optical system that receives light (503) reflected from the target or subject (510). The sensor system also includes a lidar system, which typically includes a controller that calculates distance information to the subject (506) from the reflected light, and an element that can scan or provide a specific pattern of light, which may be a static pattern, within a desired range and field of view (FOV). The transceiver optical system is used to convert the received signal light into measurements representing a point-by-point three-dimensional map of the surrounding environment within the range and FOV of the lidar system.

[0307] The receiving optics and signal processing for the LIDAR calculate range information based on measurements of the time of flight of the light pulses emitted from the light source. Furthermore, the scene is illuminated at a target plane associated with a specific range, and known information about the light beam profile based on the specific design of the source and projector system is used to determine positional information about the reflecting surfaces, thereby generating a complete x, y, z, or 3D picture of the scene. In other words, the point-by-point 3D map of the surrounding environment represents a collection of measurement data representing positional information from all surfaces reflecting the light from the source to the receiver within the LIDAR system's field of view. In this way, a 3D representation of the object in the LIDAR system's field of view is obtained.

[0308] Also shown is a schematic diagram illustrating the two-dimensional field of view and range requirements of a typical surround view LIDAR system (500) for a vehicle (502). For example, adaptive cruise control may require a field of view and range (504) with a narrower field of view compared to the side view "surround view" field of view and range (506), but with a long range requirement. Typically, the sensor functions of a vehicle may be enabled by a combination of LIDAR, radar, cameras, and ultrasonic sensors. The combination of these sensor data to generate information about the surrounding environment is often referred to as "sensor fusion."

[0309] While the present invention describes a LIDAR system in the context of an automobile, where LIDAR is widely used for autonomous, self-driving, or driver-assisted vehicles, it should be understood that the embodiments can be applied to any vehicle. Other types of vehicles include robots, tractors, trucks, airplanes, drones, boats, and ships.

[0310]

[0311] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as falling within the scope of the present invention.

[0312] In addition, although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

Claims

1. Includes first to sixth lenses sequentially arranged from the object side to the sensor side along the optical axis, The above first lens has a negative (-) refractive power, At least one of the second to sixth lenses has positive (+) refractive power, A receiving optical system in which the distance between the centers of the second lens and the second lens is the greatest among the distances between adjacent lenses on the optical axis.

2. In paragraph 1, In the above optical axis, the first lens has a concave shape on both sides, A receiving optical system in which the second lens has a convex shape on both sides of the optical axis.

3. In paragraph 1, In the above optical axis, the fourth lens has a meniscus shape with a convex object side, A receiving optical system in which the fifth lens on the optical axis has a meniscus shape with a convex object side.

4. In paragraph 1, The second to sixth lenses have positive (+) refractive power, A receiving optical system in which a filter is placed between the third lens and the fourth lens.

5. In paragraph 1, Among the first to sixth lenses, the effective diameter of the fourth lens is the largest, A receiving optical system in which the effective diameter of the sixth lens among the first to sixth lenses is the smallest.

6. In paragraph 1, A receiving optical system in which the center spacing between the second lens and the third lens on the optical axis is greater than the center thickness of the fourth lens.

7. In paragraph 1, A receiving optical system in which the effective diameters of the first to sixth lenses are larger than the maximum diagonal length of the image sensor.

8. In paragraph 1, A receiving optical system including a filter positioned adjacent to a lens having the largest effective diameter among the first to sixth lenses.

9. In any one of paragraphs 1 to 8, A receiving optical system that satisfies the following conditions. <Conditional expression> 0.1 < F / TTL < 0.5 (In the above conditional expression, F is the total focal length of the receiving optical system, and TTL is the total optical axis length of the receiving optical system.) 10. In any one of paragraphs 1 to 8, A receiving optical system that satisfies the following conditions. <Conditional expression> 1 < ┃F1┃ / F < 3 (In the above conditional expression, F1 is the focal length of the first lens, and F is the overall focal length of the receiving optical system.)

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