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, the point light source and the shaping lens are located in the lens cone and located at the opposite ends of the lens cone respectively, the face, facing the point light source, of the shaping lens is marked as a light inlet face, and the face, deviating from the point light source, of the shaping lens is marked as a light outlet face. The curvature radiuses of the light incident surface and the light emergent surface are designed so that the effective focal length of the shaping lens is located between the light emergent surface and the end surface of the lens barrel, and the spot brightness of the light spot shaped by the shaping lens is increased. Wherein the laser generated by the point light source is incident through the light incident surface, and the light emitted by the light emergent surface is parallel to the extension direction of the lens cone. The shaping lens satisfies enough long focal length, shortens the back focal length, maintains the long focal length to facilitate reduction of far-field light spots, realizes the short back focal length to facilitate reduction of leakage in the light propagation process, and improves the light utilization rate.

Description

Technical Field

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

[0002] Vertical cavity surface emitting lasers are widely used in sweeping robots and other distance measurement equipment. It is mainly used to draw spatial maps, reconstruct point clouds or measure spatial distances in real time. It is increasingly widely used in consumer robots, humanoid robots or robot dogs.

[0003] However, the vertical cavity surface emitting laser in the related art has low energy of emitted light after packaging and low light utilization rate. 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 and low light utilization of the vertical cavity surface emitting laser after packaging in the related technology.

[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 and a lens barrel;

[0006] The point light source and the shaping lens are located in the lens barrel and at opposite ends of the lens barrel respectively;

[0007] The surface of the shaping lens facing the point light source is recorded as the light incident surface, and the surface away from the point light source is recorded as the light exit surface;

[0008] The curvature radii of the light incident surface and the light exit surface are designed so that the focal length of the shaping lens is located between the light exit surface and the end surface of the lens barrel, and the point brightness of the light spot shaped by the shaping lens is increased;

[0009] The laser light generated by the point light source is incident through the light incident surface, and the light emitted from the light emitting surface is parallel to the extension direction of the lens barrel.

[0010] In one embodiment, the ratio of the curvature radius R1 of the light incident surface at the optical axis to the curvature radius R2 of the light emitting surface at the optical axis satisfies:

[0011] ;

[0012] Wherein, EFL represents the focal length of the shaping lens, BFL represents the back focal length of the shaping lens, d represents the thickness of the shaping lens along the extension direction of the optical axis, and n represents the refractive index of the material of the shaping lens.

[0013] In one embodiment, the ratio of the curvature radius R1 to the curvature radius R2 is designed to satisfy: 0.8≤R1 / R2≤1.21, so that the focal length of the shaping lens is located between the light emitting surface and the end surface of the lens barrel.

[0014] In one embodiment, the focal length EFL of the shaping lens satisfies the following formula:

[0015] ;

[0016] 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.

[0017] In one embodiment, the ratio of the back focal length BFL of the shaping lens to the focal length EFL of the shaping lens satisfies: 0.46≤BFL / EFL≤0.80.

[0018] In one embodiment, the focal length EFL of the shaping lens satisfies: 10mm≤EFL≤15mm.

[0019] 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 point 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.

[0020] In one of the embodiments, the radius r of the light emitting aperture of the point light source is ≥7.5 um, and the divergence angle a of the point light source is ≥14°.

[0021] In one embodiment, along the extension direction of the optical axis, the thickness g of the shaping lens satisfies: 1.8 mm ≤ g ≤ 2.4 mm.

[0022] According to another aspect of the present application, a smart mobile device is provided, comprising the point laser module in any one of the above embodiments.

[0023] The above-mentioned point laser module uses a shaping lens to shape the light emitted by the point light source, so that the laser generated by the point light source is incident through the light incident surface, and the light emitted from the light exiting surface is parallel to the extension direction of the lens barrel. By designing the curvature radius of the light incident surface and the light exiting surface of the shaping lens, the effective focal length or focal length of the shaping lens is located outside the shaping lens to increase the point brightness of the light spot shaped by the shaping lens. And the focal length of the shaping lens is located outside the shaping lens, which is conducive to shortening the back focus of the shaping lens. While making the shaping lens have a long focal length, shortening its back focal length is conducive to reducing leakage during light propagation, improving light utilization, and thus obtaining a better quality far-field light spot. At the same time, the light incident surface of the shaping lens can be set to a concave surface, so as to be able to utilize the deflection effect of the concave surface on the light, thereby shortening the distance between the point light source and the shaping lens, and utilizing the design of the concave-convex surface of the shaping lens to shorten the back focal length while meeting a sufficiently long focal length. Maintaining a long focal length is conducive to reducing the far-field light spot, and achieving a short back focal length is conducive to reducing the leakage during the light propagation process and improving the light utilization rate. It can be understood that part of the light will leak from the peripheral side between the point light source and the shaping lens during the propagation process, and the concave surface setting of the light incident surface of the shaping lens shortens the back focal length of the shaping lens, shortens the distance between the point light source and the shaping lens, and can reduce the light leaking from the point light source and the shaping lens, thereby helping to reduce the leakage during the light propagation process and improve the light utilization rate. And the peripheral side of the light incident surface of the concave shape extends toward the direction of the point light source, and can receive more light leaking from between the point light source and the shaping lens through the peripheral side part, reducing the risk of light leakage, which is conducive to improving the light utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the laser module of this application.

[0025] Figure 2 It is a schematic diagram of the structure of using a common plano-convex lens in the related technology for collimation.

[0026] Figure 3 for Figure 1 The embodiments shown and Figure 2 Optical path comparison diagram.

[0027] Figure 4 This is a schematic diagram of the structure of the point light source and the shaping lens of the present application being arranged relative to each other.

[0028] Description of Figure Numbers:

[0029] 10. Point laser module;

[0030] 1. Point light source; 11. Laser chip; 12. Packaging unit;

[0031] 2. Lens tube;

[0032] 3. Plastic lens; 31. Light incident surface; 32. Light exit surface. 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 with 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] See also Figure 1 As shown, Figure 1 Schematic diagram of the structure of the 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 3, wherein the point light source 1 and the shaping lens 3 are located in the lens barrel 2 and are respectively located at opposite ends of the lens barrel 2. The surface of the shaping lens 3 facing the point light source 1 is recorded as the light incident surface 31, and the surface away from the point light source 1 is recorded as the light exit surface 32. The curvature radius of the light incident surface and the light exit surface 32 is designed so that the focal length of the shaping lens 3 is located between the light exit surface 32 and the end face of the lens barrel 2, and the point brightness of the light spot shaped by the shaping lens 3 is increased, thereby obtaining a light spot with better quality. Among them, the laser generated by the point light source 1 is incident through the light incident surface 31, and the light after the light exit surface 32 is emitted is parallel to the extension direction of the lens barrel 2. The effective focal length EFL of the shaping lens 3 is located outside the shaping lens 3, which is conducive to shortening the back focus of the shaping lens 3. While making the shaping lens 3 have a long focal length EFL, shortening its back focal length BFL is conducive to reducing leakage during light propagation and improving light utilization.

[0045] In order to ensure that the focal length EFL is located in front of the lens after the light generated by the point light source 1 is incident on the shaping lens 3, the light-entering surface 31 and the light-emitting surface 32 of the shaping lens 3 in the embodiment of the present application are designed to have opposite optical focal powers, for example, the light-entering surface 31 has a positive optical focal power, and the light-emitting surface 32 has a negative optical focal power; or, the light-entering surface 31 has a negative optical focal power, and the light-emitting surface 32 has a positive optical focal power. In this way, the laser generated by the point light source 1 is incident on the light-entering surface 31, and the light emitted from the light-emitting surface 32 is parallel to the extension direction of the lens barrel 2, so that the laser generated by the point light source 1 is collimated to obtain a high-quality light spot.

[0046] The point laser module 10 of the present application designs the curvature radius of the light entrance surface 31 and the light exit surface 32 of the shaping lens 3 so that the effective focal length or focal length of the shaping lens 3 is located outside the shaping lens 3, so as to increase the point brightness of the light spot shaped by the shaping lens 3. And the focal length of the shaping lens 3 is located outside the shaping lens 3, which is conducive to shortening the back focus of the shaping lens 3. While making the shaping lens 3 have a long focal length, shortening its back focus is conducive to reducing leakage during the propagation of light, improving light utilization, and thus obtaining a better quality far-field light spot.

[0047] In some embodiments, the light incident surface 31 of the shaping lens 3 facing the point light source 1 can be designed as a concave surface, and the light exit surface 32 on the side away from the point light source 1 can be designed as a convex surface. Among them, both the concave surface and the convex surface are convex outward or concave inward relative to the lens itself. The light incident surface 31 of the shaping lens 3 is set as a concave surface, so as to be able to utilize the deflection effect of the concave surface on the light, thereby shortening the distance between the point light source 1 and the shaping lens 3. The design of the concave and convex surface of the shaping lens 3 is utilized to shorten the back focal length BFL while satisfying a sufficiently long focal length EFL. Maintaining a long focal length EFL is conducive to reducing the far-field light spot, and achieving a short back focal length BFL is conducive to reducing leakage during light propagation and improving light utilization.

[0048] The present application uses a shaping lens 3 to shape the light emitted by a point light source 1, so that the laser generated by the point light source 1 is incident through the light incident surface 31, and the light emitted from the light exit surface 32 is parallel to the extension direction of the lens barrel 2. By designing the curvature radius of the light incident surface 31 and the light exit surface 32 of the shaping lens 3, the effective focal length EFL of the shaping lens 3 is located outside the shaping lens 3, so that the light spot parameters after shaping by the shaping lens 3 meet the preset requirements. And the effective focal length EFL of the shaping lens 3 is located outside the shaping lens 3, which is conducive to shortening the back focus of the shaping lens 3. While making the shaping lens 3 have a long focal length EFL, shortening its back focal length BFL is conducive to reducing leakage during light propagation and improving light utilization. At the same time, by utilizing the deflection effect of the concave light incident surface 31 of the shaping lens 3 on the light and the shape characteristics of the concave light incident surface 31 or the concave surface itself, the back focal length BFL of the shaping lens 3 can be shortened, that is, by utilizing the concave-convex surface design of the shaping lens 3 while satisfying a sufficiently long focal length EFL, the back focal length BFL can be shortened. Maintaining the long focal length EFL is conducive to reducing the far-field light spot and achieving a short back focus, thereby facilitating shortening the distance between the point light source 1 and the shaping lens 3, reducing leakage during light propagation, and further facilitating improving the receiving effect of the shaping lens 3 on the light emitted by the point light source 1, so that more light emitted by the point light source 1 enters the shaping lens 3, thereby improving the light utilization rate. In sweeping robots and other distance measuring equipment, reducing the far-field light spot is conducive to improving the distance measurement accuracy.

[0049] 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 3 during the propagation process, and by shortening the distance between the point light source 1 and the shaping lens 3, the light leaking from between the point light source 1 and the shaping lens 3 can be reduced, thereby helping to reduce light leakage and improve light utilization. Moreover, the peripheral side of the concave light incident surface 31 extends toward the point light source 1, and more light leaking from between the point light source 1 and the shaping lens 3 can be received through the peripheral side portion, reducing the risk of light leakage, which is conducive to improving light utilization.

[0050] In some embodiments, the focal length EFL and the back focal length BFL of the shaping lens 3 satisfy, or in other words, the ratio of the curvature radius R1 of the light incident surface 31 at the optical axis to the curvature radius R2 of the light exit surface 32 at the optical axis satisfies:

[0051] ;

[0052] Wherein, d represents the thickness of the shaping lens 3 along the extension direction of the optical axis, n represents the material refractive index of the shaping lens 3 , R1 represents the curvature radius of the light incident surface 31 of the shaping lens 3 , and R2 represents the curvature radius of the light exit surface 32 of the shaping lens 3 .

[0053] In this way, the thickness, material, light entrance surface 31 and light exit surface 32 of the shaping lens 3 are designed by the above formula, so that the focal length EFL of the shaping lens 3 has a smaller back focal length BFL while satisfying the focal length EFL required by the optical system of the point laser module 10, thereby reducing the light leaking from between the shaping lens 3 and the point light source 1, which is beneficial to improve the utilization rate of the light emitted by the point light source 1 and obtain the required high-quality light spot.

[0054] In some embodiments, the ratio of the curvature radius R1 of the light incident surface 31 of the shaping lens 3 at the optical axis to the curvature radius R2 of the light emitting surface 32 at the optical axis can be designed to satisfy: 0.8≤R1 / R2≤1.21, so that the focal length EFL of the shaping lens 3 is located between the light emitting surface 32 and the end surface of the lens barrel 2. And the shaping lens 3 has a better curvature radius, corresponding to a better range of focal length EFL, which can satisfy a sufficiently long focal length EFL, which is beneficial to improve the collimation of the light emitted by the point light source 1 and to reduce the far-field light spot. At the same time, satisfying the above range is conducive to improving the convenience of preparing the shaping lens 3. Therefore, if Figure 3 As shown, Figure 3 for Figure 1 The embodiments shown and Figure 2When the newly designed shaping lens 3 of the present application is applied to the point laser module 10, while ensuring that the focal length EFL before and after replacement is the same, the back focal length BFL of the newly designed shaping lens 3 is greatly reduced, and the point brightness G of the light spot is greatly improved accordingly. Since the value of EFL has basically not changed, according to the formula of EFL, when the radius r of the light hole of the point light source 1 and the image distance L are constant, the spot radius R basically does not change, and accordingly the spot area A before and after replacement is effectively guaranteed.

[0055] In some embodiments, the focal length EFL of the shaping lens 3 satisfies: , where 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 3. For ease of description, r is referred to as the OA aperture and R is referred to as the light spot radius.

[0056] It can be seen that after the light passes through the light incident surface 31 and the light exiting surface 32, the spot area A of the far-field spot formed has an opposite trend to the point brightness G of the 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 by the radius R of the far-field spot formed by the light passing through the shaping lens 3. Point brightness refers to the light flux 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).

[0057] It can be seen that when the OA aperture r of the laser chip 11 is constant, the focal length EFL of the shaping lens 3 determines the size of the far-field light spot. The larger the focal length EFL, 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 3 is too large, usually the farther the shaping lens 3 is from the laser chip 11, the less light can enter the shaping lens 3, which will cause the brightness of the far-field light spot to decrease.

[0058] Moreover, when the focal length EFL of the shaping lens 3 is constant, the smaller the OA aperture 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 OA aperture 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 3, which affects the point brightness G of the far-field light spot. Therefore, the OA aperture of the laser chip 11, the divergence angle of the laser chip 11 and the focal length EFL of the shaping lens 3 are balanced with each other to obtain a far-field light spot with better size and brightness.

[0059] In some embodiments, the point light source 1 includes a laser chip 11, and the laser chip 11 includes the above-mentioned light-emitting aperture. Along the direction perpendicular to the optical axis, the radius r of the light-emitting aperture of the laser chip 11 satisfies: r≥7.5um, and the diameter h of the light-emitting aperture of the laser chip 11 satisfies: h≥15um. In some embodiments, the divergence angle a of the light emitted by the laser chip 11 satisfies: a≥14°. And the packaging form of the present application can be applied to the packaging of laser chips 11 of most sizes, especially laser chips 11 with larger light-emitting apertures (OA apertures), which conform to the settings of chips of most sizes and have wide applicability. 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 3, so as to obtain a far-field light spot with better size and brightness. The present application has a better shaping effect for laser chips with OA aperture and emission angle within the above-defined range. When a laser chip 11 with a larger OA aperture and a larger emission angle is used, it can still have a far-field light spot with better spot area and brightness. It can be understood that the present application can also achieve a better shaping effect for laser chips with OA aperture and emission angle not within the above-defined range.

[0060] In some embodiments, the diameter of the OA aperture of the laser chip 11 can be 15um, and the corresponding divergence angle of the emitted light can be 14°, that is, the focal length EFL of the shaping lens 3 can be selected to be 15mm, and a more suitable far-field light spot that meets the standard can be obtained.

[0061] In some embodiments, the back focal length BFL of the shaping lens 3 satisfies: 2.1≤BFL≤3.16, and the ratio of the back focal length BFL of the shaping lens 3 to the focal length EFL of the shaping lens 3 satisfies: 0.46≤BFL / EFL≤0.80. The shaping lens 3 of the present application has a smaller back focal length BFL while satisfying a sufficiently long focal length EFL, so as to meet the collimation requirements, reduce the far-field light spot, shorten the distance between the point light source 1 and the shaping lens 3, reduce the leakage during the light propagation process, improve the light utilization rate, and thus obtain a better quality far-field light spot.

[0062] In some embodiments, the focal length EFL of the shaping lens 3 satisfies: 10mm≤EFL≤15mm. The shaping lens 3 is designed to meet the focal length EFL required by the optical system, achieve straight emission of light, and maintain a long focal length EFL, which is conducive to reducing the far-field spot of the point laser module 10.

[0063] In some embodiments, the value range of the spot area A can be: 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 can be: C≥0.84, and the value range of the point brightness G can be: G≥185 grayscale values. Meeting the above requirements, a spot with a better spot area A, a higher point brightness G, and a better point roundness C can be obtained. The 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.

[0064] In some embodiments, continue to refer to Figure 1 As shown, 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 and a tube cap arranged on the tube seat, the tube seat and the tube cap define a housing cavity, the laser chip 11 is arranged in the housing cavity, and a light exit window is opened on the tube cap, the light exit window faces the shaping lens 3 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, so that the laser chip 11 faces the lens barrel 2 and emits light along the extension direction of the lens barrel 2. In some embodiments, packaging glass is installed at the light exit window, so that light can be transmitted and a seal can be formed by the packaging glass. 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.

[0065] Combined with reference Figure 2 , Figure 3 As shown in Table 1 below, Figure 2 It is a schematic diagram of the structure of using a common plano-convex lens in the related technology for collimation. Figure 3 for Figure 1 The embodiments shown and Figure 2 The following table 1 shows the parameters of the optical system after the ordinary plano-convex lens replaces the plastic lens 3. The thickness in the following table 1 refers to the distance between two adjacent optical surfaces. For example, in this embodiment, the distance between the light incident surface 31 of the ordinary plano-convex lens and the point light source 1 is 12 mm, and the distance between the light emitting surface 32 and the light incident surface 31 is 2.10 mm, that is, the thickness of the ordinary plano-convex lens in this embodiment is 2.10 mm.

[0066] Table 1 (Unit: mm)

[0067]

[0068] 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 3 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 large distance makes it easy for light to leak between the ordinary plano-convex lens and the point light source 1.

[0069] Refer to Table 2, which shows the various parameters of the plastic lens 3 of an embodiment of the present application. In this embodiment, the effective focal length EFL of the plastic lens 3 is 15 mm. Among them, the thickness refers to the distance between two adjacent optical surfaces. The thickness of 8.70 mm corresponding to the light incident surface 31 indicates that the distance between the light incident surface 31 and the point light source 1 is 8.70 mm. It can be seen that, under the premise that both the ordinary plano-convex lens and the plastic lens 3 of the present application meet the focal length EFL required by the entire optical system, the plastic lens 3 of the present application is smaller than the point light source 1, or the plastic lens 3 of the present application has a smaller back focal length BFL, which can reduce the light leaking from between the plastic lens 3 and the point light source 1, which is beneficial to improve the utilization rate of the light emitted by the point light source 1.

[0070] Table 2 (Unit: mm)

[0071]

[0072] At the same time, in combination with Table 1 and Table 2, the present application adopts a plastic lens 3, which can increase the utilization rate of the light emitted by the point light source 1 from 39.7% in the related art to 44.9%, 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.

[0073] In some embodiments, the light incident surface 31 and the light emitting surface 32 of the shaping lens 3 may both be aspherical surfaces. Figure 4 As shown, Figure 4 The schematic diagram of the structure of the point light source 1 and the shaping lens 3 of the present application are arranged relative to each other. By designing the aspherical surface of the light incident surface 31 and the light exit surface 32, the shaping lens 3 can meet the focal length EFL of the optical system while being spaced closer to the point light source 1, or in other words, the shaping lens 3 has a smaller back focal length BFL, which is beneficial to reduce the light leaking from the shaping lens 3 and the point light source 1.

[0074] In some embodiments, the surface shape function z1(r) of the light incident surface 31 and the surface shape function z2(s) of the light emitting surface 32 respectively satisfy:

[0075] ;

[0076] ;

[0077] Wherein, z1 (r) is the surface vector height of a point on the light incident surface 31 parallel to the optical axis, c is the curvature of the light incident surface 31, r is the radial distance between the light incident surface 31 and the optical axis, k is the cone constant, a2 represents the 4th-order coefficient of the surface shape function of the light incident surface 31; a3 represents the 6th-order coefficient of the surface shape function of the light incident surface 31; a4 represents the 8th-order coefficient of the surface shape function of the light incident surface 31; a5 represents the 10th-order coefficient of the surface shape function of the light incident surface 31, a6 represents the 12th-order coefficient of the surface shape function of the light incident surface 31, a7 represents the 14th-order coefficient of the surface shape function of the light incident surface 31, and a8 represents the 16th-order coefficient of the surface shape function of the light incident surface 31;

[0078] z2 (s) is the surface vector height of a point on the light emitting surface 32 parallel to the optical axis, q is the curvature of the light emitting surface 32, s is the radial distance between the light emitting surface 32 and the optical axis, p is the cone constant, b2 represents the 4th-order coefficient of the surface shape function of the light emitting surface 32; b3 represents the 6th-order coefficient of the surface shape function of the light emitting surface 32; b4 represents the 8th-order coefficient of the surface shape function of the light emitting surface 32; b5 represents the 10th-order coefficient of the surface shape function of the light emitting surface 32, b6 represents the 12th-order coefficient of the surface shape function of the light emitting surface 32, b7 represents the 14th-order coefficient of the surface shape function of the light emitting surface 32, and b8 represents the 16th-order coefficient of the surface shape function of the light emitting surface 32.

[0079] The light incident surface 31 and the light exit surface 32 satisfy the above-mentioned aspheric surface formula. Through the aspheric surface design, the shaping lens 3 has a smaller back focal length BFL, which is beneficial to improving the light utilization rate of the point laser module 10.

[0080] In some embodiments, referring to Table 2, it can be seen from Table 2 that both the light incident surface 31 and the light emitting surface 32 can be set to be aspherical surfaces, the curvature radius of the light incident surface 31 is 2.63 mm, and the curvature radius of the light emitting surface 32 is 2.60 mm. Then, along the optical axis, the distance between the light incident surface 31 and the point light source 1 is 8.7 mm, the distance between the light emitting surface 32 and the light incident surface 31 is 2.1 mm, the cone constant of the light incident surface 31 is 0, and the cone constant of the light emitting surface 32 is -0.371. The material of the plastic lens 3 can be selected from D-ZK2, which is an optical glass material with good refractive index and transmittance, as well as low dispersion, good temperature stability, high mechanical strength and other advantages.

[0081] And the 4th order coefficient a2 of the surface shape function of the light incident surface 31 is -2.54E-03, the 6th order coefficient a3 of the surface shape function of the light incident surface 31 is 2.74E-04, and the 8th order coefficient a4 of the surface shape function of the light incident surface 31 is 5.59E-06. The 4th order coefficient b2 of the surface shape function of the light exit surface 32 is -7.22E-04, the 6th order coefficient b3 of the surface shape function of the light exit surface 32 is 3.54E-06, and the 8th order coefficient b4 of the surface shape function of the light exit surface 32 is 1.59E-06. Through the design of the light incident surface 31 and the light exit surface 32 of the plastic lens 3 in Table 2, the focal length EFL of the plastic lens 3 is 15 mm, which meets the focal length EFL requirement of the optical system of the point laser module 10, and makes the back focal length BFL of the plastic lens 3 smaller, which is beneficial to improve the light utilization rate of the point laser module 10.

[0082] In some embodiments, along the extension direction of the optical axis, the thickness g of the shaping lens 3 satisfies: 1.8mm≤g≤2.4mm, so that the shaping lens 3 has better light transmission and collimation effects, which is beneficial to improving the far-field light spot quality and is also beneficial to the miniaturized 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, which facilitates 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 3 , and the adhesive layer is used to install the shaping lens 3 in the lens barrel 2 , so that the shaping lens 3 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 a point laser module as described in any of the above embodiments, and the point laser module may be arranged on 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 smart mobile device of the present application use a shaping lens 3 to shape the light emitted by the point light source 1. By designing the curvature radius of the light entrance surface 31 and the light exit surface 32 of the shaping lens 3, the effective focal length EFL of the shaping lens 3 is located outside the shaping lens 3, so that the light spot parameters after shaping by the shaping lens 3 meet the preset requirements. And the effective focal length EFL of the shaping lens 3 is located outside the shaping lens 3, which is conducive to shortening the back focus of the shaping lens 3, thereby obtaining a better quality far-field light spot. And the light entrance surface 31 of the shaping lens 3 is set to a concave surface, so that the deflection effect of the concave surface on the light can be utilized, thereby shortening the distance between the point light source 1 and the shaping lens 3. The light incident surface 31 and the light exit surface 32 of the shaping lens 3 are designed so that the focal length EFL satisfies the focal length EFL of the optical system of the point laser module 10, and the back focal length BFL of the shaping lens 3 is shortened as much as possible. Maintaining the long focal length EFL is conducive to reducing the far-field light spot, and achieving a short back focal length BFL is conducive to reducing the leakage of light during the propagation process and improving the utilization rate of light. Setting the light incident surface 31 of the shaping lens 3 as a concave surface can further shorten the distance between the point light source 1 and the shaping lens 3, thereby reducing the light leaking from the point light source 1 and the shaping lens 3, thereby reducing the light leakage, improving the utilization rate of light, and obtaining 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 and a lens barrel; The point light source and the shaping lens are located in the lens barrel and at opposite ends of the lens barrel respectively; The surface of the shaping lens facing the point light source is recorded as the light incident surface, and the surface away from the point light source is recorded as the light exit surface; the light incident surface of the shaping lens is designed to be a concave surface, and the light exit surface is designed to be a convex surface; The curvature radii of the light incident surface and the light emitting surface are respectively denoted as R1 and R2, and the ratio of R1 to R2 is designed to satisfy: 0.8≤R1 / R2≤1.21, so that the focal length of the shaping lens is located between the light emitting surface and the end surface of the lens barrel, and the point brightness of the light spot shaped by the shaping lens is increased; The laser light generated by the point light source is incident through the light incident surface, and the light emitted from the light emitting surface is parallel to the extension direction of the lens barrel.

2. The point laser module according to claim 1, characterized in that: The ratio of the curvature radius R1 of the light incident surface at the optical axis to the curvature radius R2 of the light exit surface at the optical axis satisfies: ； Wherein, EFL represents the focal length of the shaping lens, BFL represents the back focal length of the shaping lens, d represents the thickness of the shaping lens along the extension direction of the optical axis, and n represents the refractive index of the material of the shaping lens.

3. The point laser module according to claim 2, characterized in that: The back focal length BFL of the shaping lens satisfies: 2.1≤BFL≤3.

16.

4. The point laser module according to claim 2, characterized in that: The focal length EFL of the shaping lens 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.

5. The point laser module according to claim 4, characterized in that: The ratio of the back focal length BFL of the shaping lens to the focal length EFL of the shaping lens satisfies: 0.46≤BFL / EFL≤0.

80.

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

7. The point laser module according to claim 4, 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 point 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 claim 4, characterized in that: The radius r of the light emitting aperture of the point light source is ≥7.5 um, and the divergence angle a of the point light source is ≥14°.

9. The point laser module according to any one of claims 1 to 8, characterized in that: Along the extension direction of the optical axis, the thickness g of the shaping lens satisfies: 1.8 mm ≤ g ≤ 2.4 mm.

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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