Point laser module and smart mobile device

Abstract

The present application relates to a point laser module and a smart mobile device. The point laser module includes a point light source, a lens barrel, and a shaping lens group. The point light source and the shaping lens group are located in the lens barrel and are spaced apart along the extension direction of the lens barrel. The shaping lens group includes a first lens and a second lens. The first lens and the second lens are spaced apart from each other along the extension direction of the lens barrel. The curvature radius of the first lens and the second lens is designed to increase the point brightness of the light spot after being shaped by the shaping lens group. The laser generated by the point light source forms a virtual light source after passing through the first lens, and the light emitted by the virtual light source is collimated after passing through the second lens. The present application can increase the point brightness of the formed light spot through the shaping lens group, and can have a longer focal length and a shorter back focal length. Maintaining a long focal length is conducive to improving the brightness of the light spot while keeping the light spot area unchanged. Achieving a short back focal length is conducive to improving the light utilization rate, thereby taking into account both improving the point brightness of the light spot and improving the light utilization efficiency.

Description

Technical Field

[0001] The present application relates to the field of laser diode packaging technology, and in particular to a point laser module and a smart mobile device. Background Art

[0002] Laser diodes are semiconductor devices that convert electrical energy directly into laser light. They are widely used in robotic vacuum cleaners and other distance-measuring devices, primarily for mapping spaces, reconstructing point clouds, and measuring distances in real time. They are increasingly used in consumer robots, as well as humanoid robots and robotic dogs.

[0003] However, the energy of the emitted light from the laser diode after packaging in the related art is low, and the light utilization rate is low. Summary of the Invention

[0004] Based on this, it is necessary to provide a point laser module and a smart mobile device to address the problems of low energy of emitted light and low light utilization after laser diode packaging in related technologies.

[0005] According to one aspect of the present application, a point laser module is provided, comprising: a point light source, a shaping lens assembly, and a lens barrel;

[0006] The point light source and the shaping lens group are located in the lens barrel and are spaced apart along the extension direction of the lens barrel;

[0007] The shaping lens assembly includes a first lens and a second lens. The first lens and the second lens are spaced apart from each other along the extension direction of the lens barrel. The curvature radii of the first lens and the second lens are designed to increase the brightness of the light spot shaped by the shaping lens assembly.

[0008] The laser light generated by the point light source forms a virtual light source after passing through the first lens, and the light emitted by the virtual light source is collimated after passing through the second lens.

[0009] In one embodiment, the first lens includes a first light incident surface and a first light exit surface opposite to each other along the extension direction of the lens barrel, the first light incident surface faces the point light source, the first light incident surface is a plane, and the first light exit surface is a convex surface, and the second lens includes a second light incident surface facing the first lens, and a second light exit surface away from the first lens, and the second light exit surface is a convex surface.

[0010] In one embodiment, the ratio of the curvature radius R1 of the first light-emitting surface of the first lens to the curvature radius R2 of the second light-emitting surface of the second lens satisfies: 0.065≤R1 / R2≤0.15, so that the laser generated by the point light source forms the virtual light source after passing through the first lens, and the light emitted by the virtual light source is collimated after passing through the second lens.

[0011] In one embodiment, the focal length EFL of the shaping lens assembly satisfies the following formula:

[0012] ;

[0013] Wherein, r is the radius of the light-emitting aperture of the point light source, R is the radius of the light spot, and L is the image distance of the shaping lens assembly.

[0014] In one embodiment, the ratio of the back focal length BFL of the shaping lens assembly to the focal length EFL of the shaping lens assembly satisfies: 0.09≤BFL / EFL≤0.15.

[0015] In one embodiment, the focal length EFL of the shaping lens assembly satisfies: 10 mm ≤ EFL ≤ 15 mm.

[0016] In one embodiment, the spot area A of the light spot has a value range of: 300PPI≤A≤700PPI, and the spot area A is related to the radius R of the light spot; the roundness C of the light spot has a value range of: C≥0.84; the point brightness G has a value range of: G≥185 grayscale values, and the point brightness G is related to the back focal length BFL.

[0017] In one embodiment, the point light source includes a laser chip and a packaging assembly, the packaging assembly includes a tube base and a tube cap disposed on the tube base, the tube base and the tube cap define an accommodating cavity, and the laser chip is disposed in the accommodating cavity;

[0018] A light exit window is provided on the tube cap, and the light exit window faces the shaping lens assembly;

[0019] The first lens is arranged at the light exit window.

[0020] In one embodiment, the radius h of the light emitting aperture of the point light source satisfies: 6um≤h≤7.5um, and the divergence angle a of the point light source is ≥14°.

[0021] According to another aspect of the present application, a smart mobile device is provided, comprising the point laser module described in any one of the above embodiments.

[0022] The above-mentioned point laser module is provided with a shaping lens group on the light-emitting side of the point light source, which is used to shape the light emitted by the point light source so that the laser light generated by the point light source is emitted after passing through the first lens and the second lens and is parallel to the extension direction of the lens barrel. Compared with the related art of collimating the light by a single lens, the present application adopts a shaping lens group. On the one hand, by designing the curvature radius of the first lens and the second lens, the point brightness of the light spot after being shaped by the shaping lens group can be increased. On the other hand, the shaping lens group can be designed so that the first lens in the shaping lens group is closer to the point light source, which is equivalent to shortening the distance between the point light source and the shaping lens group. It can be understood that part of the light will leak out from the peripheral side between the point light source and the shaping lens group during the propagation process. By shortening the distance between the point light source and the shaping lens group, the light leaking from between the point light source and the shaping lens group can be reduced, thereby helping to reduce light leakage, or reducing the divergence during the light propagation process and improving the light utilization rate. Compared with a plano-convex lens, the use of two lenses can maintain a longer focal length while also shortening the back focal length, thereby taking into account both long focal length and short back focal length. Maintaining a long focal length is beneficial to increasing the point brightness of the light spot while keeping the light spot area unchanged, and achieving a short back focal length is beneficial to improving the utilization rate of light. That is, the present application can achieve the effect of both increasing the point brightness of the light spot and improving the efficiency of light utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the laser module of this application.

[0024] Figure 2 This is a schematic diagram of the structure of using an ordinary plano-convex lens in the related art for collimation.

[0025] Figure 3 for Figure 1 and Figure 2 A comparison diagram of the optical paths of the illustrated embodiments.

[0026] Description of Figure Numbers:

[0027] 10. Point laser module;

[0028] 1. Point light source; 11. Laser chip; 12. Packaging assembly; 121. Tube base; 122. Tube cap;

[0029] 2. Lens barrel;

[0030] 3. First lens; 31. First light incident surface; 32. First light exit surface;

[0031] 4. Second lens; 41. Second light incident surface; 42. Second light exit surface;

[0032] 5. Virtual light source. DETAILED DESCRIPTION

[0033] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0034] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0035] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0036] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0037] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0038] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0039] A vertical-cavity surface-emitting laser (VCSEL) is a special type of semiconductor laser that emits laser light vertically from the top of the chip, rather than from the side like a traditional edge-emitting laser (EEL). This VCSEL structure offers many unique advantages, such as low power consumption, high-speed modulation, ease of integration, high beam quality, good temperature stability, and low-cost manufacturing. These characteristics have led to its widespread application in optical communications, 3D sensing, LiDAR, biometric security, the Internet of Things (IoT), and augmented reality / virtual reality (AR / VR). For example, in robot vacuums and other distance-measuring devices, VCSELs are primarily used to create spatial maps, reconstruct point clouds, or measure spatial distances in real time.

[0040] The TO package (Transistor Outline) is a widely used electronic component packaging method. It forms an airtight package, protecting sensitive components from environmental influences such as humidity and dust. The TO package provides a stable packaging effect for VCSEL chips, enabling them to perform well in various applications.

[0041] However, the conventional TO package for vertical-cavity surface-emitting lasers (VCSELs) also has certain drawbacks. For example, in the application of VCSELs in sweeping robots and other ranging equipment, the far-field spot size must be sufficiently small. In other words, the collimation angle must be very small, and the far-field spot energy must be sufficiently large. However, it is difficult to balance these two requirements in the related art, making it difficult to achieve a good far-field spot. In other words, the energy utilization rate of the VCSELs after packaging in the related art is low. While the far-field spot size is sufficiently small, it is difficult to achieve the characteristic of sufficiently large far-field spot energy.

[0042] Based on this, the present application provides a point laser module and a smart mobile device with stable and reliable packaging, and at the same time, better light utilization, so that the size of the far-field light spot is small enough and the far-field light spot energy is large enough.

[0043] See Figure 1 As shown, Figure 1 This is a structural diagram of the laser module 10 of this application.

[0044] The point laser module 10 provided in this application includes a point light source 1, a lens barrel 2, and a shaping lens assembly (not shown). The point light source 1 and the shaping lens assembly are located in the lens barrel 2 and are spaced apart along the extension direction of the lens barrel 2. The shaping lens assembly includes a first lens 3 and a second lens 4. The first lens 3 and the second lens 4 are spaced apart along the extension direction of the lens barrel 2. The laser light generated by the point light source 1 is emitted after passing through the first lens 3 and the second lens 4, and is parallel to the extension direction of the lens barrel 2. Therefore, the shaping lens assembly can collimate the laser light generated by the point light source 1 to obtain a high-quality light spot. The curvature radius of the first lens 3 and the second lens 4 is designed to increase the brightness of the light spot after being shaped by the shaping lens assembly, so that the parameters of the light spot after being shaped by the first lens 3 and the second lens 4 meet the preset requirements, thereby obtaining a high-quality light spot and ensuring that the light spot formed by the shaping lens assembly meets the requirements. The laser light generated by the point light source 1 forms a virtual light source 5 after passing through the first lens 3. The light emitted by the virtual light source 5 is collimated after passing through the second lens 4.

[0045] It can be understood that the design of the curvature radius of the dual lenses improves the deflection effect of light passing through the first lens 3 and the second lens 4, resulting in a smoother light transition and improved spot quality. Furthermore, the first lens 3 in the shaping lens assembly can be designed to be closer to the point light source 1, which is equivalent to shortening the spacing between the point light source 1 and the shaping lens assembly. This shortening of the distance between the point light source 1 and the shaping lens assembly can reduce light leakage between the point light source 1 and the shaping lens assembly, thereby improving light utilization.

[0046] Compared to the related art that uses a single lens to collimate light, the present application provides a shaping lens group on the light-emitting side of the point light source 1, which is used to shape the light emitted by the point light source 1 so that the laser light generated by the point light source 1, after passing through the first lens 3 and the second lens 4, is parallel to the extension direction of the lens barrel 2. In addition, the use of the shaping lens group can ensure that the parameters of the light spot formed by the shaping lens group meet the preset requirements. At the same time, the shaping lens group can be designed to make the first lens 3 in the shaping lens group closer to the point light source 1, which is equivalent to shortening the distance between the point light source 1 and the shaping lens group. That is, the use of two lenses in the present application can maintain a longer focal length compared to a plano-convex lens, while also facilitating a shorter back focus, thereby taking into account both long focal length and short back focus. Maintaining a long focal length is conducive to increasing the brightness of the light spot while keeping the light spot area unchanged, and achieving a short back focus is conducive to improving light utilization. It can be understood that part of the light will leak out from the peripheral side between the point light source 1 and the shaping lens group during the propagation process. By shortening the distance between the point light source 1 and the shaping lens group, the light leaking from the point light source 1 and the shaping lens group can be reduced, thereby helping to reduce light leakage, or reducing the divergence of light during propagation, improving light utilization, and thus obtaining a better quality far-field light spot. This allows the present application to achieve the effect of both improving the point brightness of the light spot and improving the light utilization efficiency, while also being able to achieve the effect of improving the degree of cohesion of the far-field light spot by maintaining a long focal length. In sweeping robots and other ranging equipment, improving the degree of cohesion of the far-field light spot is conducive to improving ranging accuracy.

[0047] In some embodiments, as Figure 1 As shown, the first lens 3 includes a first light incident surface 31 and a first light exit surface 32 that are opposite to each other along the extension direction of the lens barrel 2. The first light incident surface 31 faces the point light source 1. The first light incident surface 31 is a flat surface, and the first light exit surface 32 is a convex surface, which converges the light emitted by the point light source 1. In some embodiments, the first lens 3 has positive optical power, and the second lens 4 has negative optical power.

[0048] In some embodiments, as Figure 1 As shown, the second lens 4 includes a second light-entry surface 41 facing the first lens 3 and a second light-exit surface 42 facing away from the first lens 3. The second light-exit surface 42 is convex. The second lens 4 receives the light emitted by the first lens 3 and emits the received light in a direction parallel to the optical axis. The first lens 3 and the second lens 4 cooperate to collimate the light emitted by the point light source 1. On the one hand, this helps to shorten the back focal length of the shaping lens assembly, or the distance between the first lens 3 and the point light source 1, and helps to reduce the divergence of the light during propagation, thereby improving the light utilization rate. On the other hand, it helps to increase the output power and stability of the laser and improve the light quality.

[0049] In some embodiments, the second light-entering surface 41 can be a flat surface or a concave surface. When the second light-entering surface 41 is flat, the second lens 4 is a plano-convex lens, which is simple to manufacture and has low cost. When the second light-entering surface 41 is concave, the concave design further facilitates light collection by the second light-entering surface 41, further helps reduce divergence during light propagation, and improves light utilization.

[0050] In some embodiments, the ratio of the curvature radius R1 of the first light-emitting surface 32 of the first lens 3 to the curvature radius R2 of the second light-emitting surface 42 of the second lens 4 satisfies the following: 0.065≤R1 / R2≤0.15. In this way, the laser light generated by the point light source 1 can form a virtual light source 5 after passing through the first lens 3, and the light emitted by the virtual light source 5 can be collimated after passing through the second lens 4. In addition, the light-emitting surfaces of the first lens 3 and the second lens 4 both have an optimal curvature radius, so that the first lens 3 and the second lens 4 can cooperate with each other, while maintaining a longer focal length and having a shorter back focal length, thereby taking into account the effects of improving the point brightness of the light spot and improving the efficiency of light utilization.

[0051] In some embodiments, the focal length EFL of the plastic surgery lens assembly of the present application satisfies:

[0052] ;

[0053] Here, r is the radius of the luminous aperture of point light source 1, also known as the OA aperture, R is the radius of the light spot, or far-field spot, and L is the image distance of the shaping lens assembly. For ease of description, r is referred to as the OA aperture, and R is referred to as the light spot radius.

[0054] It can be seen that after the light passes through the first lens 3 and the second lens 4, the far-field spot area A and the spot brightness G change in opposite directions. The spot area refers to the projected area of the laser light generated by the point light source 1 on a specific cross section. It can be derived from the radius R of the far-field spot formed by the light passing through the shaping lens assembly. The spot brightness refers to the luminous flux emitted per unit solid angle in the normal direction per unit light source area, also known as the luminous intensity per unit area of the luminous surface (candela / square meter).

[0055] It can be seen that when the radius r of the laser chip 11 is constant, the focal length EFL of the shaping lens assembly determines the size of the far-field light spot. The larger the focal length, the smaller the area A of the far-field light spot, making it easier to meet the requirements. However, when the focal length EFL of the shaping lens assembly is too large, the farther the shaping lens assembly is from the laser chip 11, the less light can enter the shaping lens assembly, resulting in reduced brightness of the far-field light spot.

[0056] Furthermore, when the focal length (EFL) of the shaping lens assembly is constant, the smaller the laser chip 11, the smaller the corresponding far-field spot size and the smaller the far-field spot area (A), making it easier to meet the requirements. However, the smaller the laser chip 11, the larger the corresponding divergence angle, and the less energy can be incident on the shaping lens assembly, affecting the brightness (G) of the far-field spot. Therefore, a balance between the size of the laser chip 11, the divergence angle of the laser chip 11, and the focal length (EFL) of the shaping lens assembly is required to achieve a far-field spot with optimal size and brightness.

[0057] In some embodiments, the focal length (EFL) of the shaping lens assembly of the present application satisfies the following conditions: 10 mm ≤ EFL ≤ 15 mm. By designing the shaping lens assembly to meet the required focal length (EFL) of the optical system, the light is emitted straightly while maintaining a long focal length (EFL). This helps improve the brightness of the far-field spot of the point laser module 10 while maintaining the same area.

[0058] In some embodiments, the ratio of the back focal length BFL of the shaping lens assembly to the focal length EFL of the shaping lens assembly satisfies the following: 0.09 ≤ BFL / EFL ≤ 0.15. The shaping lens assembly of the present application, while maintaining a sufficiently long focal length EFL, has a relatively short back focal length BFL, thereby facilitating alignment requirements. This improves the brightness of the far-field light spot while maintaining the same area of the far-field light spot of the point laser module 10, while also shortening the distance between the point light source 1 and the shaping lens assembly. This reduces light leakage during propagation, improves light utilization, and ultimately achieves a higher-quality far-field light spot.

[0059] In some embodiments, the value range of the spot area A is: 300PPI≤A≤700PPI, where PPI is the number of pixels per inch, that is, the spot area A is between 300 PPI and 700 PPI. The value range of the point roundness C is: C≥0.84, the value range of the point brightness G is: G≥185 grayscale values, and the point brightness G is related to the back focal length BFL. Meeting the above requirements, a light spot with a better spot area A, a higher point brightness G, and a better point roundness C can be obtained. Point roundness refers to the degree to which the cross section of the workpiece is close to the theoretical circle. It is used to quantify the error of the circle, that is, the distance from the center of the circle. For example, when used in sweeping robots and other ranging equipment, it can provide more accurate spatial mapping effects and measure more accurate spatial distances, which greatly improves the actual application effect of the product.

[0060] In some embodiments, as Figure 1The point light source 1 includes a laser chip 11 and a packaging group 12, and the laser chip 11 is packaged on the packaging group 12. The packaging group 12 includes a tube base 121 and a tube cap 122 provided on the tube base 121. The tube base 121 and the tube cap 122 define an accommodating cavity. The laser chip 11 is arranged in the accommodating cavity. A light exit window is opened on the tube cap 122. The light exit window faces the shaping lens group in the lens barrel 2, and the light exit direction of the light exit window is parallel to the extension direction of the lens barrel 2. The light emitted by the laser chip 11 is emitted through the light exit window and enters the interior of the lens barrel 2, and is then collimated by the shaping lens group. Through the above-mentioned packaging, the laser chip 11 of the present application has better packaging stability, which is beneficial to protecting the laser chip 11. In some embodiments, the laser chip 11 of the present application adopts a vertical cavity surface emitting laser (VCSEL), and the packaging group 12 adopts a TO package.

[0061] In some embodiments, continue to refer to Figure 1 As shown, the first lens 3 is arranged at the light exit window. It can be understood that the light exit window is a window such as a hole opened on the tube cap 122 for transmitting light. The first lens 3 is arranged at the light exit window, which is equivalent to replacing the original window flat glass with the first lens 3. In this way, the light can be transmitted and the first lens 3 and the second lens 4 can be used to collimate the light. The first lens 3 can cooperate with the second lens 4 to achieve the effect of taking into account both long focal length and short back focal length. Maintaining the long focal length is conducive to improving the point brightness of the far-field light spot of the point laser module 10 while keeping the area of the far-field light spot unchanged. Achieving a short back focal length is conducive to improving the light utilization rate, that is, taking into account the effect of improving the point brightness of the light spot and improving the light utilization efficiency, which is conducive to obtaining a high-quality far-field light spot with a smaller light spot area A and a larger point brightness G.

[0062] In some embodiments, the first lens 3 is provided on the tube cap 122, and the first lens 3 is sealed at the light exit window, and the laser chip 11 in the packaging group 12 is sealed by the packaging glass. It can be understood that the first lens 3 is sealed at the light exit window, and the first lens 3 and the second lens 4 are designed to cooperate with each other, so that the collimation effect is achieved and the long focal length is maintained. At the same time, the first lens 3 is closer to the point light source 1, and a short back focal length is achieved, which shortens the distance between the point light source 1 and the shaping lens group, and can reduce the light leaking from the point light source 1 and the shaping lens group. Therefore, by maintaining the long focal length, it is beneficial to improve the brightness of the light spot while keeping the light spot area unchanged, and achieving a short back focal length is beneficial to reducing light leakage, or reducing the divergence during the light propagation process, thereby improving the light utilization rate.

[0063] See also Figure 2 、 Figure 3 As shown in Table 1, Figure 2 This is a schematic diagram of the structure of using an ordinary plano-convex lens in the related art for collimation. Figure 3 for Figure 1 and Figure 2 The optical path comparison diagram of the embodiment shown, Figure 3 EFL represents the effective focal length of the shaping lens assembly of the present application, BFL represents the back focal length of the shaping lens assembly of the present application, and BFL1 represents the back focal length in the related art. Table 1 shows the parameters of the optical system after replacing the shaping lens assembly with an ordinary plano-convex lens. The thickness in Table 1 refers to the distance between two adjacent optical surfaces. For example, in this embodiment, the distance between the light incident surface and point light source 1 of the ordinary plano-convex lens is 12 mm, and the distance between the light exit surface and the light incident surface is 2.10 mm, that is, the thickness of the ordinary plano-convex lens in this embodiment is 2.10 mm.

[0064] Table 1 (Unit: mm)

[0065]

[0066] It can be seen that when an ordinary plano-convex lens is used for collimation, under the premise that both the ordinary plano-convex lens and the shaping lens assembly of the present application meet the focal length required by the entire optical system, the distance between the ordinary plano-convex lens and the point light source 1 needs to be 12 mm. The distance is large, and light is easily leaked between the ordinary plano-convex lens and the point light source 1.

[0067] With reference to Table 2, Table 2 lists the main design parameters of the shaping lens group in one embodiment of the present application. In this embodiment, the effective focal length EFL of the shaping lens group is 15 mm. The thickness in Table 2 refers to the distance between two adjacent optical surfaces. For example, in this embodiment, the distance between the first light incident surface 31 and the point light source 1 is 1.8 mm, that is, the first lens 3 is 11.8 mm away from the point light source. The distance between the first light exiting surface 32 and the first light incident surface 31 is 0.5 mm, that is, the thickness of the first lens 3 is 0.5 mm. The distance between the second light incident surface 41 and the first light exiting surface 32 is 10.1 mm, that is, the distance between the second lens 4 and the first lens 3 is 10.1 mm. The distance between the second light exiting surface 42 and the second light incident surface 41 is 1.5 mm, that is, the thickness of the second lens 4 is 1.5 mm.

[0068] Table 2 (Unit: mm)

[0069]

[0070] Table 3 (Unit: mm)

[0071]

[0072] With reference to Table 3, Table 3 lists the main design parameters of the shaping lens assembly in another embodiment of the present application. In this embodiment, the effective focal length EFL of the shaping lens assembly is 10 mm. Similarly, the thickness in Table 3 refers to the distance between two adjacent optical surfaces. For example, in this embodiment, the distance between the first light incident surface 31 and the point light source 1 is 1.8 mm, that is, the first lens 3 is 11.8 mm away from the point light source. The distance between the first light exiting surface 32 and the first light incident surface 31 is 0.5 mm, that is, the thickness of the first lens 3 is 0.5 mm. The distance between the second light incident surface 41 and the first light exiting surface 32 is 5.00 mm, that is, the distance between the second lens 4 and the first lens 3 is 5.00 mm. The distance between the second light exiting surface 42 and the second light incident surface 41 is 2.00 mm, that is, the thickness of the second lens 4 is 2.00 mm.

[0073] It can be seen that no matter whether the effective focal length EFL of the shaping lens group in the embodiment of Table 2 is 15 mm or the effective focal length of the embodiment of Table 3 is 10 mm, on the premise that the ordinary plano-convex lens and the shaping lens group of the present application both meet the focal length required by the entire optical system, the distance between the first lens 3 of the present application and the point light source 1 can be 11.8 mm. The distance between the first lens 3 of the present application and the point light source 1 is smaller, or in other words, the shaping lens group of the present application has a smaller back focal length, which can reduce the light leaking from between the collimating lens and the point light source 1, which is beneficial to improve the utilization rate of the light emitted by the point light source 1.

[0074] At the same time, referring to Tables 1, 2 and 3, the present application adopts a shaping lens group. When the effective focal length EFL of the shaping lens group is 15 mm, the utilization rate of the light emitted by the light source can be increased from 39.7% in the related art to 51%. When the effective focal length EFL of the shaping lens group is 10 mm, the utilization rate of the light emitted by the point light source 1 can be increased from 39.7% in the related art to 77%. Both greatly improve the utilization rate of the light emitted by the point light source 1, which is beneficial to improving the far-field light spot energy.

[0075] Continuing to refer to Table 2 above, the first light-emitting surface 32 and the second light-emitting surface 42 can both be aspherical surfaces, and the aspherical surface shapes must satisfy the surface shape function:

[0076] ;

[0077] Wherein, z (r) is the surface sag of a point on the corresponding surface parallel to the optical axis, c is the curvature of the corresponding surface, r is the radial distance between the corresponding surface and the optical axis, k is the cone constant, a2 represents the 4th-order coefficient of the surface function of the corresponding surface; a3 represents the 6th-order coefficient of the surface function of the corresponding surface; a4 represents the 8th-order coefficient of the surface function of the corresponding surface; a5 represents the 10th-order coefficient of the surface function of the corresponding surface, a6 represents the 12th-order coefficient of the surface function of the corresponding surface, a7 represents the 14th-order coefficient of the surface function of the corresponding surface, and a8 represents the 16th-order coefficient of the surface function of the corresponding surface.

[0078] In this embodiment, as shown in Table 2, the radius of curvature of the first light-emitting surface 32 can be set to 0.46 mm, and the radius of curvature of the second light-emitting surface 42 can be set to 5.65 mm. Both the first light-incident surface 31 and the second light-incident surface 41 are planes, and their conic constants are both 0. The coefficients of the higher-order terms of their surface shape functions are also 0. The conic constant of the first light-emitting surface 32 is -0.913, and the conic constant of the second light-emitting surface 42 is 0.481. The 4th order coefficient of the surface function of the first light-emitting surface 32 is -4.74E-01, the 6th order coefficient is 5.19E-01, the 8th order coefficient is -5.68E-01, and the 10th order coefficient is 0. The 4th order coefficient of the surface function of the second light-emitting surface 42 is -7.28E-04, the 6th order coefficient is -2.21E-05, the 8th order coefficient is -6.86E-07, and the 10th order coefficient is -2.97E-08. In this way, the light can be collimated by the first lens 3 and the second lens 4, and a longer focal length can be maintained, which is beneficial to improving the brightness of the light spot while keeping the spot area unchanged. The shaping lens group can have a shorter back focal length while meeting the focal length required by the entire optical system, which is beneficial to shortening the distance between the shaping lens group and the point light source 1, reducing the divergence during light propagation, improving light utilization, and obtaining a better far-field light spot.

[0079] In some embodiments, as shown in Table 2, the material of the first lens 3 and the second lens 4 can be BK7. BK7 is an optical glass material with high transmittance, capable of effectively transmitting light within the visible light range and reducing light scattering and absorption, thereby further improving light utilization. BK7 also has a high Abbe number, resulting in low dispersion and excellent color correction performance. It can reduce chromatic aberration caused by light passing through the glass surface, thereby improving the imaging quality of the optical system. In addition, BK7 also has advantages such as high refractive index uniformity, low bubble content, low impurity content, low thermal expansion coefficient, good chemical resistance, and a wide transmission range, which can meet the needs of different optical systems and is cost-effective.

[0080] In some embodiments, the radius h of the light-emitting aperture of the point light source 1 satisfies: 6um≤h≤7.5um, and the divergence angle a of the point light source 1 is ≥14°. Therefore, the packaging form of the present application can be applied to the packaging of laser chips 11 of most sizes, conforms to the setting of chips of most sizes, and has a wide applicability. And the laser chip 11 can have a suitable light-emitting angle through the appropriate OA aperture of the laser chip 11, and cooperate with the focal length EFL of the above-mentioned shaping lens group, thereby obtaining a far-field light spot with better size and brightness. It can be understood that the present application can also achieve a better shaping effect for laser chips 11 whose OA aperture and light-emitting angle are not within the above range.

[0081] In some embodiments, the diameter of the OA aperture of the laser chip 11 is 15 μm, corresponding to a divergence angle of the emitted light of 14°. The focal length EFL of the shaping lens group can be selected to be 15 mm, so that a more suitable far-field light spot that meets the standard can be obtained.

[0082] In some embodiments, along the extension direction of the lens barrel 2, the thickness g of the first lens 3 satisfies the following conditions: 0.4 mm ≤ g ≤ 1.0 mm, and the thickness q of the second lens 4 satisfies the following conditions: 1.2 mm ≤ q ≤ 1.8 mm. This ensures that both the first lens 3 and the second lens 4 have excellent light transmission and collimation effects, helps maintain a long focal length, improves far-field spot quality, and facilitates the miniaturization of the point laser module 10.

[0083] In some embodiments, the radial dimension L of the lens barrel 2 along the extension direction perpendicular to the lens barrel 2 satisfies: 4 mm ≤ L ≤ 6 mm. This can facilitate the miniaturization design of the point laser module 10 while meeting the collimation requirements.

[0084] In some embodiments, an adhesive layer is provided between the lens barrel 2 and the shaping lens assembly, and the adhesive layer is used to install the shaping lens assembly in the lens barrel 2 so that the shaping lens assembly can be stably installed in the lens barrel 2 .

[0085] Based on the same inventive concept, the present application also provides a smart mobile device, which may include a device body and the point laser module 10 described in any of the aforementioned embodiments. The point laser module 10 may be disposed on or within the device body for detection. Specifically, the smart mobile device of the present application includes, but is not limited to, a sweeping robot, an AGV, and a robotic dog.

[0086] The point laser module 10 and smart mobile device of the present application collimate the light emitted by the point light source 1 through the shaping lens group, and design the curvature radius of the first lens 3 and the second lens 4 so that the focal length of the shaping lens group meets the focal length of the optical system of the point laser module 10. This can increase the point brightness of the light spot after being shaped by the shaping lens group, and at the same time, make the distance between the shaping lens group and the point light source 1 shorter, thereby reducing the light leaking from the point light source 1 and the shaping lens group, or reducing the divergence during the light propagation process, thereby improving the light utilization rate. It can maintain a longer focal length, which is beneficial to improving the point brightness of the light spot while keeping the light spot area unchanged, and also shorten the back focal length, which is beneficial to improving the light utilization rate. That is, the present application can achieve the effect of both improving the point brightness of the light spot and improving the light utilization efficiency. Placing the first lens 3 at the light exit window can further shorten the distance between the point light source 1 and the shaping lens group, thereby reducing the light leaking from between the point light source 1 and the shaping lens group, thereby helping to reduce light leakage, improve light utilization, and obtain a better quality far-field light spot.

[0087] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A point laser module, characterized in that: The point laser module includes: a point light source, a shaping lens group and a lens barrel; The point light source and the shaping lens group are located in the lens barrel and are spaced apart along the extension direction of the lens barrel; The shaping lens assembly includes a first lens and a second lens. The first lens and the second lens are spaced apart from each other along the extension direction of the lens barrel. The curvature radii of the first lens and the second lens are designed to increase the brightness of the light spot shaped by the shaping lens assembly. The ratio of the back focal length BFL of the shaping lens assembly to the focal length EFL of the shaping lens assembly satisfies the following formula: 0.09≤BFL / EFL≤0.

15. The focal length EFL of the shaping lens assembly satisfies the following formula: ； Wherein, r is the radius of the light aperture of the point light source, R is the radius of the light spot, and L is the image distance of the shaping lens assembly; the spot area A of the light spot has a value range of: 300 PPI ≤ A ≤ 700 PPI, and the spot area A is related to the radius R of the light spot; the roundness C of the light spot has a value range of: C ≥ 0.84; the point brightness G has a value range of: G ≥ 185 grayscale values, and the point brightness G is related to the back focal length BFL; In which, the ratio of the curvature radius R1 of the first light-emitting surface of the first lens to the curvature radius R2 of the second light-emitting surface of the second lens satisfies: 0.065≤R1 / R2≤0.15, the laser generated by the point light source forms a virtual light source after passing through the first lens, and the light emitted by the virtual light source is collimated after passing through the second lens.

2. The point laser module according to claim 1, characterized in that: The first lens includes a first light incident surface and a first light exit surface opposite to each other along the extension direction of the lens barrel, the first light incident surface faces the point light source, the first light incident surface is a plane, and the first light exit surface is a convex surface, the second lens includes a second light incident surface facing the first lens, and a second light exit surface away from the first lens, and the second light exit surface is a convex surface.

3. The point laser module according to claim 2, characterized in that: The second light incident surface is a flat surface or a concave surface.

4. The point laser module according to claim 1, characterized in that: Along the extending direction of the lens barrel, a thickness g of the first lens satisfies: 0.4 mm ≤ g ≤ 1.0 mm, and a thickness q of the second lens satisfies: 1.2 mm ≤ q ≤ 1.8 mm.

5. The point laser module according to claim 1, characterized in that: The focal length EFL of the shaping lens assembly satisfies: 10 mm ≤ EFL ≤ 15 mm.

6. The point laser module according to any one of claims 1 to 5, characterized in that: The point light source includes a laser chip and a packaging component group, the packaging component group includes a tube base and a tube cap provided on the tube base, the tube base and the tube cap define an accommodating cavity, and the laser chip is provided in the accommodating cavity; A light exit window is provided on the tube cap, and the light exit window faces the shaping lens assembly; The first lens is arranged at the light exit window.

7. The point laser module according to claim 6, characterized in that: The radius h of the light emitting aperture of the point light source satisfies: 6um≤h≤7.5um, and the divergence angle a of the point light source is ≥14°.

8. A smart mobile device, characterized in that: The device comprises a device body and a point laser module as described in any one of claims 1 to 7.

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