Multi-beam light source module

Abstract

The application relates to the technical field of optical devices, in particular to a multi-beam light source module, which comprises a substrate, a plurality of sub-light sources and an optical element; the plurality of sub-light sources are arranged on the substrate respectively, and each sub-light source is used for emitting a light beam along the Z-axis direction; the optical element comprises a plurality of deflection units, the deflection units are arranged in one-to-one correspondence with the sub-light sources, each deflection unit is used for causing the light beam emitted by the corresponding sub-light source to be deflected on the X-Z plane and the Y-Z plane, and then causing the light beam emitted by each sub-light source to be emitted from the optical element at different exit angles. Through one-to-one correspondence between the sub-light sources and the deflection units, independent double-plane deflection regulation and control of each light beam are realized, the multi-beam light is accurately emitted at different angles, the demand of multi-directional light beam projection for eyeball tracking is met, and at the same time, cross talk between different light beams is avoided, and the accuracy of light beam emission is improved.

Description

Technical Field

[0001] This application relates to the field of optical device technology, and in particular to a multi-beam light source module. Background Technology

[0002] A multi-beam light source module is a light source module that can emit multiple beams of light at different angles. It is mainly used in AR, VR, smart glasses and other fields. Its working principle is to project beams of light at different angles onto the eyeball and identify the direction of eyeball movement by detecting the reflected light from the eyeball. It is the core device for realizing eye tracking function.

[0003] With the development of mobile smart device technology, AR, VR, and smart glasses are gradually evolving towards smaller size and lower power consumption. This requires the internal functional modules of these devices to simultaneously meet the design requirements of low power consumption, small size, and high precision. Currently, the mainstream method for tracking eye movements in the AR, VR, and smart glasses fields is real-time camera-based visual monitoring. This method has high algorithm requirements and requires microprocessors to calculate image information in real time. This not only results in a large computational load and high power consumption but also places high demands on the hardware's computing and storage capabilities, making it difficult to adapt to the miniaturization and low power consumption trends of smart wearable devices.

[0004] To address the aforementioned issues, there is an urgent need to design a low-power, small-size, and low-hardware-requirement multi-beam light source module to meet the eye-tracking application needs of AR / VR, smart glasses, and other devices. Summary of the Invention

[0005] This application provides a multi-beam light source module to solve the problems of high power consumption and high requirements for hardware and algorithms in existing eye-tracking technologies, and to achieve low power consumption, small size, and high precision beam emission and angle control, adapting to the design requirements of smart wearable devices such as AR / VR and smart glasses.

[0006] This application provides a multi-beam light source module, including a substrate, multiple sub-light sources, and optical elements; the multiple sub-light sources are respectively disposed on the substrate, and each sub-light source is used to emit a beam along the Z-axis direction; the optical elements include multiple deflection units, which are disposed one-to-one with the sub-light sources, and each deflection unit is used to deflect the beam emitted by the corresponding sub-light source in the XZ plane and YZ plane, thereby causing the beam emitted by each sub-light source to be emitted from the optical elements at different exit angles.

[0007] By establishing a one-to-one correspondence between sub-light sources and deflection units, independent dual-plane deflection control of each beam is achieved, ensuring that multiple beams are accurately emitted at different angles, meeting the needs of eye tracking for multi-directional beam projection, while avoiding crosstalk between different beams and improving the accuracy of beam emission.

[0008] Furthermore, a positive electrode pad and a negative electrode pad are provided on the substrate, and the sub-light source includes a light source chip. One side of the light source chip is a positive electrode and the other side is a negative electrode. The positive electrode of the light source chip is electrically connected to the positive electrode pad, and the negative electrode of the light source chip is electrically connected to the negative electrode pad.

[0009] Furthermore, the positive electrode of the light source chip is electrically connected to the positive electrode pad via wire bonding, and the negative electrode of the light source chip is electrically connected to the negative electrode pad via conductive adhesive.

[0010] The connection method combining wire bonding and conductive adhesive balances the stability of electrical conduction with the requirement of small module size. The conductive adhesive achieves integrated physical fixation and electrical conduction between the negative electrode of the light source chip and the pad, without occupying additional space. Wire bonding enables precise connection between the tiny pad and the positive electrode of the chip, which is suitable for the miniaturization of the light source chip. At the same time, this connection method has low power consumption, further reducing the overall power consumption of the module.

[0011] Furthermore, the sub-light source uses a laser light source chip or an LED light source chip.

[0012] Both types of light source chips are miniature semiconductor devices with extremely small dimensions, perfectly suited to the design goals of small-volume modules. Both also feature low power consumption, with low power consumption per chip, effectively controlling the overall power consumption of the module. The laser light source chip offers better directionality and monochromaticity, improving eye-tracking accuracy. The LED light source chip has a simpler structure and lower cost, allowing for flexible selection based on product precision requirements and cost budgets, thus enhancing the module's product adaptability.

[0013] Furthermore, the deflection unit can be a prism. The mirror surface on which the light beam emitted by the sub-source light source is refracted is the working surface of the prism. The working surface of the prism has a preset tilt angle in the XZ plane and the YZ plane, respectively.

[0014] The prism achieves simultaneous deflection of the light beam in two planes through a dual-dimensional tilted working surface. Based on the principle of light refraction, the light power loss during the deflection process is low, which can maximize the retention of the output power of the sub-source light source and ensure the effectiveness of the reflected light detection. Furthermore, the prism has a simple structure without complex microstructures, making it easy to process and assemble, and it has good mass production capabilities. In addition, the micro prism unit is small in size and will not increase the overall size of the module after integration, thus meeting the requirements of miniaturization.

[0015] Furthermore, the deflection unit can also be a grating. The grating has a periodic micro-optical structure. By adjusting the periodic spacing, depth, width and other parameters of the micro-optical structure as well as the arrangement direction, the beam can be accurately deflected in the XZ plane and YZ plane based on the principle of light diffraction.

[0016] The microstructure of the grating can be designed with ultra-precision through micro-nano fabrication. The control precision of the diffraction deflection angle is much higher than that of conventional optical elements, which greatly improves the accuracy of beam emission and meets the high precision requirements of eye tracking. The grating has a planar design with extremely thin unit thickness. The volume of the component after integrating multiple gratings is much smaller than that of prisms and lenses, further reducing the overall size of the module. The deflection angle and direction can be customized by simply adjusting the microstructure parameters and arrangement direction. The design is highly flexible and does not require changing the overall geometry, so it can adapt to different beam deflection requirements.

[0017] Furthermore, the deflection unit can also be a lens unit, which includes a first spherical surface and a second spherical surface. The first spherical surface and the second spherical surface are arranged along the Z-axis direction. The first spherical surface is used to adjust the angle of deflection of the beam in the XZ plane, and the second spherical surface is used to adjust the angle of deflection of the beam in the YZ plane.

[0018] By using two spherical surfaces to achieve independent deflection control of the beam in two planes, the deflection angles in the horizontal and vertical directions become two independent adjustable parameters. Designers can set the deflection angle in each direction individually and easily combine them to create any desired exit angle in three-dimensional space, significantly reducing the difficulty of optical design. The spherical structure of the lens has a certain collimating effect on the beam, which can improve the directionality of the emitted beam and make the beam projected onto the designated part of the eye more accurate. At the same time, the lens has a wider range of deflection angle adjustment, adapting to more diverse eye-tracking beam projection needs.

[0019] Furthermore, the curvature of the first sphere changes continuously in the X-axis direction and remains constant in the Y-axis direction; the curvature of the second sphere remains constant in the X-axis direction and changes continuously in the Y-axis direction.

[0020] The spherical design with unidirectional curvature variation ensures that each sphere deflects the beam only on a designated plane, avoiding mutual interference between the deflections of two planes and improving the control accuracy of the deflection angle in each direction; the design with continuously varying curvature enables smooth beam deflection, avoiding problems such as beam dispersion and distortion, and ensuring the quality of the emitted beam; the design with constant curvature in the direction of the beam ensures that there is no additional refraction in that direction, further ensuring the directionality and accuracy of beam deflection.

[0021] Furthermore, the substrate includes a ceramic substrate or an FR4 substrate.

[0022] Ceramic substrates possess excellent thermal conductivity, insulation, and structural stability, enabling rapid dissipation of heat generated by the light source chip during operation. This prevents excessive internal temperatures from affecting device performance and lifespan, making them suitable for high-power, high-precision applications. FR4 substrates are inexpensive, have mature processing technology, are lightweight, and possess good electrical connectivity, making them suitable for consumer smart wearable products where cost and weight are more critical. Both substrates have good load-bearing capacity, stably fixing components such as the light source chip and optical elements, ensuring the overall stability of the module structure.

[0023] Furthermore, this multi-beam light source module also includes a bracket, with a substrate mounted on one side of the bracket and optical elements disposed on the opposite side of the bracket.

[0024] The bracket provides stable mounting support and precise positioning reference for the substrate and optical components, ensuring that the sub-light source and the corresponding deflection unit are accurately aligned in space, avoiding beam incident deviation due to installation errors, and improving the accuracy of beam deflection.

[0025] The beneficial effects of this application are as follows: The multi-beam light source module of this application has each sub-light source as a laser light source chip or an LED light source chip. In order to meet the requirements of human eye safety, the output light power of a single chip is only a few milliwatts, and the power consumption is extremely low. In addition, the module does not require a microprocessor to calculate image information in real time, so the hardware computing requirements are low. The connection method of each component also has low power consumption loss, further reducing the overall power consumption and adapting to the low power consumption requirements of smart wearable devices.

[0026] The light source chip is a miniature semiconductor device. The substrate, optical elements, and bracket are all miniaturized, and the connection between the components is compact (such as wire bonding and conductive adhesive bonding). There is no extra redundant structure, which can minimize the size of the entire light source module and meet the small-volume layout requirements of AR / VR, smart glasses and other devices.

[0027] The deflection units of the optical elements correspond one-to-one with the sub-light sources. Each deflection unit can independently customize the beam deflection angle. Through different designs of prisms, gratings, and lens units, the beam can be accurately deflected in the XZ and YZ planes. The precise positioning of the bracket further ensures the accuracy of beam incident and deflection, enabling multiple beams of light to be accurately projected onto different parts of the eyeball at different angles, achieving high-precision eye tracking.

[0028] The module consists of only a substrate, sub-light source, optical elements, and bracket. It has few core components, and the connection and assembly methods between the components are all based on mature semiconductor and optical device technologies, which facilitates mass production and reduces maintenance costs. At the same time, the support of the bracket, the positioning of the solder pads, and the stable electrical connection all improve the overall structure and operational reliability of the module and extend its service life. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the multi-beam light source module provided in the embodiments of this application; Figure 2 A schematic diagram of the front side of the substrate of the multi-beam light source module provided in the embodiments of this application; Figure 3 This is a schematic diagram of the back side of the substrate of the multi-beam light source module provided in the embodiments of this application; Figure 4 A schematic diagram showing the connection between the substrate and the pads of the multi-beam light source module provided in an embodiment of this application; Figure 5 A schematic diagram of the bracket and optical components of the multi-beam light source module provided in the embodiments of this application; Figure 6 This is a schematic diagram of the deflection unit of the multi-beam light source module provided in Embodiment 1 of this application. Figure 7 This is a schematic diagram of the deflection unit of the multi-beam light source module provided in Embodiment 2 of this application. Figure 8 This is a schematic diagram of the deflection unit of the multi-beam light source module provided in Embodiment 3 of this application. Figure label: 1. Substrate; 11. Positive electrode pad; 12. Negative electrode pad; 2. Sub-light source; 21. Light source chip; 3. Optical element; 31. Prism; 32. Grating; 33. Lens assembly; 331. First spherical surface; 332. Second spherical surface; 4. Support. Detailed Implementation

[0031] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The following is combined Figures 1-8 This describes the multi-beam light source module provided in the embodiments of this application.

[0033] Example 1: The multi-beam light source module in this embodiment uses a prism as the deflection unit. (Refer to...) Figure 1-5 as well as Figure 6 As shown, the module includes a substrate 1, eight sub-light sources 2, optical elements 3, and a support 4. The substrate 1 is a ceramic substrate. The front side of the substrate 1 has independent positive and negative electrode pads 11 and 12. The positive and negative polarity of the pads are set according to the control logic of the sub-light sources 2. The negative electrode pad 12 is used to support the sub-light sources 2. The eight sub-light sources 2 are arranged in an array on the negative electrode pad 12 on the front side of the substrate 1. Each sub-light source 2 is a laser light source chip 21. The back side of the laser light source chip 21 is the negative electrode, which is physically fixed and electrically connected to the negative electrode pad 12 via conductive adhesive. The front side of the laser light source chip 21 is the positive electrode, which is electrically connected to the positive electrode pad 11 via wire bonding. Each laser light source chip 21 emits a laser beam along the Z-axis.

[0034] The support 4 is a rigid plastic support, with the substrate 1 mounted on its lower side. The optical element 3 is fixed to the upper side of the support 4 using adhesive. The optical element 3 includes eight deflection units, each corresponding to a sub-light source 2. Specifically, each deflection unit is a prism 31. Each prism 31 precisely corresponds to the light outlet of a laser light source chip 21. The working surface of the prism 31 is the core surface for beam refraction. The working surface is tilted 10° to the left in the XZ plane and 8° upward in the YZ plane. When the beam emitted by the laser light source chip 21 is incident along the Z-axis onto the working surface of the prism 31, it is deflected 10° to the left in the XZ plane and 8° upward in the YZ plane based on the principle of light refraction, finally exiting from the prism 31 at a preset spatial angle. In this way, by utilizing the double-dimensional tilted working surface of the prism, precise double-plane deflection of the beam is achieved, and the independent deflection of a single prism also avoids beam crosstalk.

[0035] In this embodiment, the working surfaces of the eight prisms 31 are designed with different XZ and YZ plane tilt angles, so that the beams emitted by the eight sub-light sources 2 are projected at different spatial exit angles, achieving beam coverage of different parts of the eyeball. Combined with reflected light detection, the direction of eyeball rotation can be identified. The different angles of the prism working surfaces enable differentiated and precise projection of multiple beams of light, which can comprehensively cover different detection parts of the eyeball, so that all directions of eyeball rotation can be accurately identified, improving the sensitivity and accuracy of eye tracking.

[0036] Example 2 In this embodiment, the multi-beam light source module uses a grating 32 as a deflection unit. The structure and connection method of the substrate 1, sub-light source 2, and support 4 are the same as in Embodiment 1, except that the deflection unit uses a grating 32. The optical element 3 includes eight gratings 32 corresponding one-to-one with the sub-light source 2. Each grating 32 has a periodic micro-groove structure. By adjusting the periodic spacing, depth, and arrangement direction of the micro-grooves of each grating 32, the beam emitted by the corresponding laser light source chip 21 is directionally deflected in the XZ and YZ planes based on the principle of light diffraction. The eight gratings 32 have different micro-optical structure parameters, enabling the eight beams to exit at different angles. Furthermore, the grating 32 is a planar micro-structure, further reducing the volume of the optical element 3 and making the entire module more compact. Thus, the ultra-precise microstructure of grating 32 achieves ultra-high precision in beam deflection. Combined with the high directionality of the laser light source chip, this enables higher levels of eye-tracking accuracy, meeting the application requirements of high-end AR / VR devices. The planar microstructure of grating 32 further reduces the module size, allowing the module to be adapted to smaller smart glasses products. The grating 32 design with different microstructure parameters enables precise and differentiated deflection of multiple beams of light, and the low optical power loss in the diffraction process ensures the effectiveness of reflected light detection.

[0037] Example 3 In this embodiment, the multi-beam light source module uses a lens unit as the deflection unit. (Refer to...) Figure 1-5 as well as Figure 7 As shown, the module includes a substrate 1, eight sub-light sources 2, optical elements 3, and a support 4. The substrate 1 is an FR4 substrate, with a positive electrode pad 11 and a negative electrode pad 12 on the front side. The eight sub-light sources 2 are arranged in a matrix on the negative electrode pad 12 of the substrate 1, and each sub-light source 2 is an LED light source chip 21. The back side of the LED light source chip 21 is electrically connected to the negative electrode pad 12 through conductive adhesive, and the front side is electrically connected to the positive electrode pad 11 through wire bonding. Each LED light source chip 21 emits an LED beam along the Z-axis.

[0038] Optical element 3 includes eight deflection units corresponding one-to-one with sub-light source 2. The deflection units are lens assemblies. Lens assembly 33 has a first spherical surface 331 and a second spherical surface 332 arranged sequentially along the Z-axis. The curvature of the first spherical surface 331 changes continuously in the X-axis direction and remains consistent in the Y-axis direction, and is used only to adjust the deflection angle of the beam in the XZ plane; the curvature of the second spherical surface 332 remains consistent in the X-axis direction and changes continuously in the Y-axis direction, and is used only to adjust the deflection angle of the beam in the YZ plane.

[0039] Thus, the dual-spherical independent deflection design of the lens unit allows the deflection angle of each plane to be adjusted individually. Designers can flexibly set the deflection parameters according to the actual needs of eye tracking. The continuous change of curvature ensures the smoothness of beam deflection, avoids beam distortion, and improves the quality of the emitted beam. The one-to-one lens unit design ensures that the deflection of each beam is accurate and interference-free.

[0040] The support 4 is a metal support, and the substrate 1 is fixed to the lower side of the support 4. The optical element 3 is integrally connected to the support 4. Each lens assembly 33 is precisely aligned with the corresponding LED light source chip 21. The light beam emitted by the LED light source chip 21 first passes through the first spherical surface 331 along the Z-axis, and is deflected at a preset angle in the XZ plane. Then it passes through the second spherical surface 332 and is deflected at a preset angle in the YZ plane, finally forming a customized spatial emission angle. The spherical curvature parameters of the eight lens assemblies 33 are different, so that the eight beams are emitted at different angles to achieve high-precision eye tracking.

[0041] The multi-beam light source module of this application realizes the electrical connection and support of each component through a substrate. The sub-light source emits beams along the Z-axis, and the deflection unit of the optical element corresponds one-to-one with the sub-light source to realize the precise deflection of the beam in the XZ and YZ planes, so that multiple beams of light are emitted at different angles. The module has a simple overall structure, small size, low power consumption, and flexible design. Different light source chips and deflection units can be selected according to actual needs, which effectively solves the defects of existing eye tracking technology. It can be widely used in AR / VR, smart glasses, optical modules and other fields, and has high practical value and mass production prospects.

[0042] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A multi-beam light source module, characterized in that, include: substrate; The sub-light source includes multiple sub-light sources, which are respectively disposed on the substrate, and each sub-light source is used to emit a light beam along the Z-axis direction; An optical element comprising a plurality of deflection units, each deflection unit being disposed on the substrate in a one-to-one correspondence with a sub-light source. Each deflection unit is used to deflect the light beam emitted by the corresponding sub-light source in the XZ plane and YZ plane, thereby causing the light beam emitted by each sub-light source to exit from the optical element at a different exit angle.

2. The multi-beam light source module according to claim 1, characterized in that, The substrate is provided with a positive electrode pad and a negative electrode pad. The sub-light source includes a light source chip, one side of which is a positive electrode and the other side is a negative electrode. The positive electrode of the light source chip is electrically connected to the positive electrode pad, and the negative electrode of the light source chip is electrically connected to the negative electrode pad.

3. The multi-beam light source module according to claim 2, characterized in that, The positive electrode of the light source chip is electrically connected to the positive electrode pad via wire bonding, and the negative electrode of the light source chip is electrically connected to the negative electrode pad via conductive adhesive.

4. The multi-beam light source module according to claim 1, characterized in that, The sub-light source uses a laser light source chip or an LED light source chip.

5. The multi-beam light source module according to claim 1, characterized in that, The deflection unit is a prism. The mirror surface on which the light beam emitted by the sub-light source is refracted is the working surface of the prism. The working surface of the prism has a preset tilt angle in the XZ plane and the YZ plane, respectively.

6. The multi-beam light source module according to claim 1, characterized in that, The deflection unit employs a grating, which uses a micro-optical structure to deflect the light beam in the XZ and YZ planes.

7. The deflection unit adopts a lens assembly, which includes a first spherical surface and a second spherical surface. The first spherical surface and the second spherical surface are arranged along the Z-axis direction. The first spherical surface is used to adjust the angle of deflection of the light beam in the XZ plane, and the second spherical surface is used to adjust the angle of deflection of the light beam in the YZ plane.

8. The multi-beam light source module according to claim 1, characterized in that, The curvature of the first sphere changes continuously in the X-axis direction and remains constant in the Y-axis direction; the curvature of the second sphere remains constant in the X-axis direction and changes continuously in the Y-axis direction.

9. The multi-beam light source module according to claim 8, characterized in that, The substrate includes a ceramic substrate or an FR4 substrate.

10. The multi-beam light source module according to claim 1, characterized in that, It also includes a bracket, with the substrate mounted on one side of the bracket and the optical element disposed on the opposite side of the bracket.

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