Point laser module and intelligent mobile device

Abstract

The invention relates to a point laser module and intelligent mobile equipment. The point laser module comprises a point light source, a lens cone and a shaping lens group, the point light source and the shaping lens group are located in the lens cone and are arranged at intervals in the extending direction of the lens cone, the shaping lens group comprises a first lens and a second lens, and the first lens and the second lens are arranged at intervals in the extending direction of the lens cone. The curvature radiuses of the first lens and the second lens are designed to be capable of increasing the point brightness of the light spots shaped by the shaping lens group, laser generated by the point light source forms a virtual light source after passing through the first lens, and light emitted by the virtual light source is collimated after passing through the second lens. Through the shaping lens group, the spot brightness of the formed light spot can be increased, a long focal length and a short back focal length can be achieved, the long focal length is maintained, the light spot brightness is improved under the condition that the light spot area is not changed, the short back focal length is achieved, the light utilization rate is improved, and therefore the spot brightness of the light spot and the light utilization efficiency are both improved.

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 can directly convert electrical energy into laser light. Laser diodes are widely used in sweeping robots and other distance measurement equipment, mainly used to draw spatial maps, reconstruct point clouds or measure spatial distances in real time. They are increasingly used in consumer robots and humanoid robots or robot 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, the point laser module comprising: a point light source, a shaping lens group and a lens barrel;

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

[0007] The shaping lens group includes a first lens and a second lens, and the first lens and the second lens are arranged at a distance from each other along the extension direction of the lens barrel, and the curvature radii of the first lens and the second lens are designed to increase the point brightness of the light spot shaped by the shaping lens group;

[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 emitting 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 emitting surface is a convex surface, and the second lens includes a second light incident surface facing the first lens, and a second light emitting surface away from the first lens, and the second light emitting 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 of the embodiments, the spot area A of the light spot is in the 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 is in the range of C≥0.84; the point brightness G is in the 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 component group, the packaging component group includes a tube seat and a tube cap disposed on the tube seat, the tube seat and the tube cap define an accommodating cavity, and the laser chip is disposed in the accommodating cavity;

[0018] The tube cap is provided with a light exit window, and the light exit window faces the shaping lens assembly;

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

[0020] In one of the embodiments, 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 light emitted by the laser generated by the point light source after passing through the first lens and the second lens is parallel to the extension direction of the lens barrel. Compared with the collimation of light by a single lens in the related art, 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 shaping 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, and by shortening the distance between the point light source and the shaping lens group, the light leaked from between the point light source and the shaping lens group can be reduced, thereby helping to reduce light leakage, or reduce the divergence during the light propagation process, and improve 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 light utilization. That is, the present application can achieve the effect of both increasing the point brightness of the light spot and improving light utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic diagram of the structure of the laser module of the present application.

[0024] FIG. 2 is a schematic diagram of a structure in which a common plano-convex lens in the related art is used for collimation.

[0025] FIG. 3 is a comparison diagram of the optical paths of the embodiments shown in FIG. 1 and FIG. 2 .

[0026] Description of Figure Numbers:

[0027] 10. Point laser module;

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

[0029] 2. Lens tube;

[0030] 3. first lens; 31. first light incident surface; 32. first light exiting surface;

[0031] 4. second lens; 41. second light incident surface; 42. second light exiting surface;

[0032] 5. Virtual light source. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0034] In the description of the present 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 the present 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 the present application.

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

[0036] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0037] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it 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. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in 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 a central 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 a central element at the same time. 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 implementation method.

[0039] Vertical Cavity Surface Emitting Laser (VCSEL) is a special type of semiconductor laser, whose laser is emitted vertically from the top of the chip, rather than from the side like the traditional edge emitting laser (EEL). This structure of VCSEL brings many unique advantages, such as low power consumption, high-speed modulation, easy integration, high beam quality, good temperature stability and low-cost manufacturing. These characteristics of VCSEL make them widely used in optical communications, 3D sensing, LiDAR, biometric security, Internet of Things (IoT) and augmented reality / virtual reality (AR / VR). For example, in sweeping robots and other ranging equipment, it is mainly used to draw spatial maps, reconstruct point clouds or measure spatial distances in real time.

[0040] TO package (Transistor Outline) is a packaging form of electronic components, which is widely used in various electronic components. It forms an airtight package to protect the sensitive components inside from environmental humidity and dust. TO package can provide a stable packaging effect for VCSEL chips, enabling them to perform well in various applications.

[0041] However, the ordinary use of TO packaging to package vertical cavity surface emitting lasers (VCSELs) also has certain defects. For example, in the application of VCSEL in sweeping robots and other distance measurement equipment, the size of its far-field light spot is often required to be small enough. In other words, its collimation angle needs to be very small, and its far-field light spot energy needs to be large enough. However, it is difficult to take into account the above two requirements in the related technology, and it is difficult to have a better far-field light spot. In other words, the energy utilization rate of the VCSEL packaged in the related technology is low. When the size of the far-field light spot is small enough, it is difficult to make it have the characteristics of sufficiently large far-field light spot energy.

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

[0043] Please refer to FIG. 1 , which is a schematic structural diagram of a laser module 10 of the present application.

[0044] The point laser module 10 provided in the present application includes a point light source 1, a lens barrel 2 and a shaping lens group (not shown in the figure), the point light source 1 and the shaping lens group are located in the lens barrel 2 and are arranged at intervals along the extension direction of the lens barrel 2. The shaping lens group includes a first lens 3 and a second lens 4, and the first lens 3 and the second lens 4 are arranged at intervals along the extension direction of the lens barrel 2, wherein the laser 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, so that the laser generated by the point light source 1 can be collimated by the shaping lens group 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 point brightness of the light spot after being shaped by the shaping lens group, so that the parameters of the light spot after being shaped by the first lens 3 and the second lens 4 in sequence meet the preset requirements, thereby obtaining a light spot with better quality, so that the light spot formed by the shaping lens group meets the requirements. Among them, the laser generated by the point light source 1 forms a virtual light source 5 after passing through the first lens 3, and 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 double lens is conducive to improving the deflection effect of the light passing through the first lens 3 and the second lens 4, making the light transition smoothly, and improving the quality of the light spot. At the same time, the first lens 3 in the shaping lens group 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 group. Shortening the distance between the point light source 1 and the shaping lens group can reduce the light leaking from the point light source 1 and the shaping lens group, thereby improving the light utilization rate.

[0046] Compared with the collimation of light by a single lens in the related art, 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 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. And by using the shaping lens group, while making the light spot parameters formed by the shaping lens group meet the preset requirements, 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 present application uses two lenses, relative to a plano-convex lens, which can maintain a longer focal length and is also conducive to shortening the back focal length, thereby taking into account both long focal length and short back focal length. Maintaining a long focal length is conducive to increasing the point brightness of the light spot while keeping the light spot area unchanged, and achieving a short back focal length is conducive to improving the light utilization rate. 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 between 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 obtaining a better quality far-field light spot. Thereby, the present application can 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 condensation of the far-field light spot by maintaining a long focal length. In sweeping robots and other ranging equipment, increasing the condensation of the far-field light spot is conducive to improving ranging accuracy.

[0047] In some embodiments, as shown in FIG1 , the first lens 3 includes a first light incident surface 31 and a first light emitting 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 plane, and the first light emitting 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 a positive optical power, and the second lens 4 has a negative optical power.

[0048] In some embodiments, as shown in FIG1 , the second lens 4 includes a second light incident surface 41 facing the first lens 3, and a second light emitting surface 42 facing away from the first lens 3, the second light emitting surface 42 is a convex surface, and 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. By collimating the light emitted by the point light source 1 through the cooperation of the first lens 3 and the second lens 4, on the one hand, it is helpful to shorten the back focal length of the shaping lens group or the distance between the first lens 3 and the point light source 1, and to reduce the divergence in the process of light propagation, and improve the utilization rate of light. On the other hand, it is helpful to improve the output power and stability of the laser and improve the quality of light.

[0049] In some embodiments, the second light incident surface 41 can be a plane or a concave surface. When the second light incident surface 41 is a plane, the second lens 4 is a plano-convex lens, which is easy to manufacture and has low cost. When the second light incident surface 41 is a concave surface, the design of the light incident surface being a concave surface is further beneficial to the light collection of the second light incident surface 41, and further helps to reduce the divergence of light during the propagation process, thereby improving the light utilization rate.

[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: 0.065≤R1 / R2≤0.15. In this way, the laser 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 is 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 a better curvature radius, so that the first lens 3 and the second lens 4 can cooperate with each other, while being able to maintain a longer focal length, having a shorter back focal length, thereby taking into account the effect 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] Among them, r is the radius of the light aperture of the point light source 1 or the OA aperture, R is the radius of the light spot or the far-field light spot, and L is the image distance of the shaping lens group. For the convenience 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 spot area A of the far-field light spot formed has an opposite trend to the point brightness G of the light spot. The spot area refers to the projection area of ​​the laser generated by the point light source 1 on a certain cross section, which can be obtained from the radius R of the far-field light spot formed by the light passing through the shaping lens group. Point brightness refers to the light flow emitted by the unit light source area in the normal direction and within the unit solid angle, also known as the light intensity of the 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 group 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, and the easier it is to meet the requirements. When the focal length EFL of the shaping lens group is too large, the farther the shaping lens group is from the laser chip 11, the less light can enter the shaping lens group, which will cause the brightness of the far-field light spot to decrease.

[0056] Moreover, when the focal length EFL of the shaping lens group is constant, the smaller the size of the laser chip 11, the smaller the size of the corresponding far-field light spot, and the smaller the far-field light spot area A, the easier it is to meet the requirements. However, the smaller the size of the laser chip 11, the larger the corresponding divergence angle of the laser chip 11, and the smaller the energy that can be incident on the shaping lens group, which affects the brightness G of the far-field light spot. Therefore, the size of the laser chip 11, the divergence angle of the laser chip 11 and the focal length EFL of the shaping lens group are balanced with each other to obtain a far-field light spot with better size and brightness.

[0057] In some embodiments, the focal length EFL of the shaping lens group of the present application satisfies: 10mm≤EFL≤15mm. Through the design of the shaping lens group, the focal length EFL required by the optical system is met, the straight emission of light is achieved, and the long focal length EFL is maintained, which is conducive to improving the point brightness of the far-field light spot of the point laser module 10 while the area of ​​the far-field light spot remains unchanged.

[0058] In some embodiments, the ratio of the back focal length BFL of the shaping lens group to the focal length EFL of the shaping lens group satisfies: 0.09≤BFL / EFL≤0.15. The shaping lens group of the present application has a smaller back focal length BFL while satisfying a sufficiently long focal length EFL, so as to facilitate meeting the collimation requirements, and to facilitate improving the point brightness of the far-field light spot while shortening the distance between the point light source 1 and the shaping lens group while keeping the area of ​​the far-field light spot of the point laser module 10 unchanged, so as to reduce leakage during light propagation, improve light utilization, and thereby obtain a better 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 shown in FIG1 , the 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 seat 121 and a tube cap 122 provided on the tube seat 121, and the tube seat 121 and the tube cap 122 define a housing cavity, and the laser chip 11 is provided in the housing cavity. A light exit window is provided on the tube cap 122, and 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 then collimated by the shaping lens group. Through the above packaging, the laser chip 11 of the present application has better packaging stability, which is conducive 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 packaging form.

[0061] In some embodiments, referring to FIG. 1 , the first lens 3 is disposed 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 light transmission. The first lens 3 is disposed 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, so that by maintaining the long focal length, it is beneficial to improve 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, and achieving short back focal length is beneficial 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 small light spot area A and a large point brightness G.

[0062] In some embodiments, the first lens 3 is disposed 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 leaked from the point light source 1 and the shaping lens group, so that maintaining a long focal length is conducive to improving the point brightness of the light spot while keeping the light spot area unchanged, and achieving a short back focal length is conducive to reducing light leakage, or reducing the divergence during the light propagation process, and improving the light utilization rate.

[0063] Referring to Figures 2, 3 and Table 1, Figure 2 is a schematic diagram of the structure of collimation using an ordinary plano-convex lens in the related art. Figure 3 is a comparison diagram of the optical paths of the embodiments shown in Figures 1 and 2. The EFL in Figure 3 represents the effective focal length of the shaping lens group of the present application, the BFL represents the back focal length of the shaping lens group of the present application, and the BFL1 represents the back focal length in the related art. Table 1 shows the various parameters of the optical system after the ordinary plano-convex lens replaces the shaping lens group. 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 of the ordinary plano-convex lens and the point light source 1 is 12 mm, and the distance between the light emitting 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 relatively large, and light leakage between the ordinary plano-convex lens and the point light source 1 is easy.

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

[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 group in another embodiment of the present application. In this embodiment, the effective focal length EFL of the shaping lens group is 10mm. 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 1.8mm, that is, the first lens 3 is 11.8mm away from the point light source. The distance between the first light emitting surface 32 and the first light incident surface 31 is 0.5mm, that is, the thickness of the first lens 3 is 0.5mm. The distance between the second light incident surface 41 and the first light emitting surface 32 is 5.00mm, that is, the distance between the second lens 4 and the first lens 3 is 5.00mm. The distance between the second light emitting surface 42 and the second light incident surface 41 is 2.00mm, that is, the thickness of the second lens 4 is 2.00mm.

[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, under 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, and 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, in combination with reference 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%, which greatly improves the utilization rate of the light emitted by the point light source 1 and is beneficial to improving the far-field 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 designed as aspherical surfaces, and the aspherical surface shapes need to satisfy the surface shape function:

[0076] ;

[0077] Wherein z (r) is the surface vector height 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. The first light incident surface 31 and the second light incident surface 41 are both planes, and their cone constants are both 0, and the high-order coefficients of the surface functions of the two are also 0. The cone constant of the first light emitting surface 32 is -0.913, and the cone 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 improve the point brightness of the light spot while the area of ​​the light spot remains 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 the light propagation process, improving the light utilization rate, 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, which is an optical glass material with high transmittance, which can effectively transmit light in the visible light range and reduce the scattering and absorption of light, which is conducive to further improving the utilization rate of light. BK7 also has a high Abbe number, so it has a low dispersion type and good color correction performance. It can reduce the chromatic aberration caused by light passing through the glass surface and improve the imaging quality of the optical system. In addition, BK7 also has the advantages of high uniformity of refractive index, few bubbles, low impurity content, low thermal expansion coefficient, good chemical corrosion resistance, wide transmission range, can meet the needs of different optical systems, and high cost performance.

[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≥14° of the point light source 1. 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 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, so as to obtain 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 the laser chip 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 15um, and the divergence angle of the corresponding outgoing light is 14°. The focal length EFL of the shaping lens group can be selected to be 15mm, and 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: 0.4mm≤g≤1.0mm, and the thickness q of the second lens 4 satisfies: 1.2mm≤q≤1.8mm. Thus, both the first lens 3 and the second lens 4 have better light transmission and collimation effects, which is conducive to maintaining a long focal length, improving the quality of the far-field light spot, and facilitating the miniaturization design of the point laser module 10.

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

[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 an intelligent mobile device, which may include a device body and the point laser module 10 described in any of the above embodiments, and the point laser module 10 may be arranged on the device body or inside the device body for detection. Specifically, the intelligent mobile device of the present application includes but is not limited to a sweeping robot, an AGV, and a mechanical dog.

[0086] The point laser module 10 and the intelligent 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, and can increase the point brightness of the light spot after shaping 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, and improving the light utilization rate. It can maintain a longer focal length to improve the point brightness of the light spot while keeping the area of ​​the light spot unchanged, and shorten the back focal length to improve 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-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A point laser module, characterized in that: The point laser module comprises: 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 arranged at intervals along the extension direction of the lens barrel; The shaping lens group includes a first lens and a second lens, and the first lens and the second lens are arranged at a distance from each other along the extension direction of the lens barrel, and the curvature radii of the first lens and the second lens are designed to increase the point brightness of the light spot shaped by the shaping lens group; 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.

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 emitting 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 emitting surface is a convex surface, the second lens includes a second light incident surface facing the first lens, and a second light emitting surface away from the first lens, and the second light emitting surface is a convex surface.

3. The point laser module according to claim 2, characterized in that: 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.

4. The point laser module according to claim 1, characterized in that: The focal length EFL of the shaping lens assembly satisfies the following formula: ； 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.

5. The point laser module according to claim 4, characterized in that: 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.

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

7. The point laser module according to claim 5, characterized in that: The value range of the spot area A of the light spot is: 300PPI≤A≤700PPI, and the spot area A is related to the radius R of the light spot; the value range of the roundness C of the light spot 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.

8. The point laser module according to any one of claims 1 to 7, characterized in that: The point light source comprises a laser chip and a packaging component group, the packaging component group comprises a tube seat and a tube cap arranged on the tube seat, the tube seat and the tube cap define an accommodating cavity, and the laser chip is arranged in the accommodating cavity; The tube cap is provided with a light exit window, and the light exit window faces the shaping lens assembly; The first lens is arranged at the light exit window.

9. The point laser module according to claim 8, 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°.

10. A smart mobile device, characterized in that: It comprises a device body and a point laser module as described in any one of claims 1-9.

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