Laser scanning device and electronic device

Abstract

The application discloses a laser scanning device and electronic equipment, which comprises a fiber actuator, a lens and a galvanometer assembly. The fiber actuator is connected with an optical fiber and drives the optical fiber to vibrate and scan on a first plane at a first working frequency under the drive of an external driving signal, and an external laser beam is emitted into the lens through the optical fiber. The galvanometer assembly is provided with a reflecting mirror, which has a first inclination angle and can rotate and vibrate around an axis parallel to the first plane at a second working frequency under the drive of an external driving signal, so as to project and reflect the light emitted from the lens to a preset area and form an image. Through the laser scanning device, the size of the laser scanning device can be reduced while the imaging quality is ensured.

Description

Technical Field

[0001] This application relates to the field of laser imaging, and more particularly to a laser scanning device and an electronic device including such a laser scanning device. Background Technology

[0002] Laser scanning technology is a technique that scans a target area by controlling the direction and path of a laser beam. It is widely used in fields such as displays, medicine, autonomous driving, and AR displays. In some scenarios, laser scanning technology can be implemented using components such as actuators, optical fibers, and galvanometers.

[0003] In laser scanning, actuators drive optical fibers or galvanometers to scan the laser beam. Common actuator types include piezoelectric actuators and microelectromechanical systems (MEMS) actuators. Piezoelectric actuators utilize the inverse piezoelectric effect of piezoelectric materials, applying voltage to electrodes to induce mechanical deformation, thereby causing the optical fiber or galvanometer to vibrate. MEMS actuators, on the other hand, control the vibration of the optical fiber or galvanometer based on MEMS technology. In laser scanning technology, optical fibers primarily serve as the light transmission medium, transmitting laser light from the source to the scanning area. The fiber optic scanner uses actuators to drive the vibration or oscillation of the optical fiber, thus achieving beam scanning. The galvanometer, as an optical scanning element, is driven by a high-speed motor or piezoelectric actuator. By changing the angle of the mirror, the direction of the laser beam is controlled, enabling various scanning modes such as linear scanning, sawtooth scanning, and helical scanning. These components each play a crucial role in laser scanning technology, meeting the needs of different application scenarios while simultaneously satisfying the requirements for overall module miniaturization and ensuring image quality. Summary of the Invention

[0004] In view of this, embodiments of this application provide a laser scanning device and an electronic device employing such a laser scanning device to at least partially solve the above-mentioned problems.

[0005] According to an embodiment of this application, a laser scanning device is provided, which includes an fiber optic actuator, a lens, and a galvanometer assembly.

[0006] The fiber actuator is connected to an optical fiber and, under the drive of an external driving signal, drives the optical fiber to vibrate and scan on a first plane at a first working frequency. An external laser beam forms a linear scanning trajectory after passing through the optical fiber and enters the lens.

[0007] The lens is located at a predetermined position between the fiber actuator and the galvanometer, with at least one light-incident surface facing the light-out end of the fiber and its light-out surface facing the reflective mirror.

[0008] The reflecting mirror of the galvanometer assembly has a first tilt angle and can rotate and vibrate at a second operating frequency around an axis parallel to the first plane under external drive, reflecting the light emitted from the lens to a preset area to form an image.

[0009] In one alternative embodiment, the positional relationship between the lens and the galvanometer in the laser scanning device is determined by the first tilt angle, the characteristic parameters of the lens, the optical fiber parameters, and the size of the reflecting mirror.

[0010] In one optional embodiment, the optical distance l between the entrance pupil position of the reflecting lens and the reflecting lens is less than or equal to 82 mm, and the position where the field rays of each field of view that form the trajectory after the fiber scanning intersect in space after passing through the lens is the entrance pupil position of the galvanometer.

[0011] In one alternative embodiment, the lens includes at least two sets of lenses, wherein the distance between the center point of the light-emitting surface of the last set of lenses and the center point of the reflecting lens is determined by the first tilt angle and the characteristic parameters of the lens and the size of the reflecting lens.

[0012] In one optional embodiment, the entrance pupil position of the reflecting lens is at an optical distance l from the reflecting lens, and the width W and height H of the reflecting lens are related to the lens parameters and the first tilt angle as follows:

[0013]

[0014] Where f is the focal length of the lens, NA is the object-side numerical aperture NA of the lens, h is the object-side dimension h of the lens, and θ is the first tilt angle θ of the reflecting mirror.

[0015] In one optional embodiment, the distance from the optical fiber oscillation initiation point to the optical fiber output end face is r, and the distance l' between the entrance pupil position of the reflecting mirror and the image-side principal plane of the lens is:

[0016]

[0017] In one optional embodiment, the distance L between the galvanometer reflecting lens and the image-side principal plane of the lens is the sum of the distance l' between the entrance pupil position of the reflecting lens and the image-side principal plane of the lens, and the optical distance l between the entrance pupil position of the reflecting lens and the reflecting lens. When the entrance pupil position is behind the galvanometer along the direction of light propagation, l is a negative value; when the entrance pupil position is in front of the galvanometer along the direction of light propagation, l is a positive value.

[0018] L=l+l′

[0019] The relationship between the distance L between the galvanometer reflecting mirror and the image-side principal plane of the lens, the lens parameters, α (lateral field of view), the size of the reflecting mirror, and the first tilt angle θ is as follows:

[0020]

[0021] In one optional embodiment, the distance L between the galvanometer reflecting lens and the image-side principal plane of the lens is equal to the distance l between the image-side principal plane of the lens and the last surface of the lens. H’ :

[0022]

[0023] Among them, the H of the galvanometer m Outer frame dimensions, H l β is the external dimensions of the reflecting mirror, and β is the longitudinal field of view.

[0024] In one alternative implementation, the area A of the reflecting mirror is less than 20 mm². 2 In an optional embodiment, the entrance pupil position of the reflecting lens and the optical distance l of the reflecting lens are obtained as follows:

[0025]

[0026] In one alternative embodiment, the reflective lens is a semi-reflective mirror that allows a portion of the light entering the reflective lens to pass through and enter a photoelectric sensor. The photoelectric sensor generates a feedback signal based on the change in the portion of the optical fiber to adjust the driving parameters of the optical fiber actuator.

[0027] This application also provides an electronic device, characterized in that it includes the laser scanning device described in any of the foregoing embodiments.

[0028] The laser scanning device provided in the above embodiments can achieve decoupling of fast-axis and slow-axis vibration. The fiber optic fast-axis drive can directly utilize the resonant frequency, eliminating the need for complex matching relationships between the fiber optic characteristic frequency, actuator characteristic frequency, and drive frequency, thus avoiding nonlinearity. Fast-axis scanning is achieved with extremely low drive voltage. This significantly increases the robustness of device parameters and greatly reduces manufacturing requirements. Furthermore, when the fiber optic actuator employs piezoelectric one-dimensional high-frequency scanning, the high-frequency vibrating component exhibits extremely low vibration inertia. Compared to MEMS high-frequency mirrors, this reduces processing requirements, lowers drive power consumption, and improves fatigue resistance. Attached Figure Description

[0029] The accompanying drawings are intended only to illustrate and explain this application and do not limit the scope of this application.

[0030] Figure 1 This is a schematic diagram illustrating the principle of laser scanning technology.

[0031] Figure 2 This is a schematic diagram of a laser scanning device provided in an embodiment of this application;

[0032] Figure 3 This is a side view of a laser scanning device provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the actuator installation in a laser scanning device provided in this application embodiment;

[0034] Figure 5 This is a reference schematic diagram of a magnet structure in a laser scanning device provided in an embodiment of this application;

[0035] Figure 6 This is a complete product drawing of a laser scanning device assembly provided in this application embodiment;

[0036] Figure 7 This is a schematic diagram of the optical imaging principle where the lens is placed behind the galvanometer assembly;

[0037] Figure 8 When the lens is positioned behind the galvanometer assembly, the overall object plane distribution in the lens design is shown in the following diagram:

[0038] Figure 9 This is a reference diagram for the optical field design when a lens is placed between the galvanometer assembly and the optical fiber output end face.

[0039] Figure 10 This is a reference diagram of the galvanometer optical path;

[0040] Figure 11 This is a schematic diagram illustrating the derivation of parameters for a preferred embodiment in this application.

[0041] Figure 12 This is a schematic block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0042] To provide a clearer understanding of the technical features, objectives, and effects of the embodiments of this application, the specific implementation methods of the embodiments of this application will now be described with reference to the accompanying drawings.

[0043] In this document, “illustrative” means “serving as an example, illustration or description”, and any illustration or implementation described herein as “illustrative” should not be construed as a more preferred or advantageous technical solution.

[0044] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, to make the drawings concise and easy to understand, in some drawings, components with the same structure or function are only schematically shown as one or more, or only one or more are labeled.

[0045] Please refer to Figure 1 It is a schematic diagram of the principle of laser scanning technology. Figure 1 As can be seen, laser scanning technology can include actuators, optical fibers, and galvanometers, and achieve high-speed spatial modulation and precise positioning of the laser beam through beam manipulation schemes.

[0046] Among them, actuators serve as the core drive for dynamic control, acting as the actuators for mechanical motion, or converting electrical signals into physical deflections of a galvanometer. Common types include electromagnetic (voice coil motors), piezoelectric (ceramic actuators), and electrostatic (MEMS micro-actuators). Piezoelectric actuators are suitable for high-frequency vibration scenarios, while MEMS electrostatic actuators drive miniature galvanometers through electrostatic force, enabling kHz-level scanning frequencies.

[0047] Optical fiber, used as a flexible transmission and mode-controlled laser transmission medium, typically employs a cantilever structure. One end of the fiber is fixed to an actuator, while the other end serves as the output end for scanning. The scanning mode can be achieved by controlling the actuator's vibration frequency and phase, such as Lissajous scanning or raster scanning.

[0048] As a key actuator for beam deflection, the galvanometer achieves two-dimensional spatial deflection of the laser beam by changing the angle of the reflecting mirror surface. It is divided into two categories: single-axis (line scanning) and dual-axis (plane scanning).

[0049] The laser scanning device 1 includes an optical fiber 11. The optical fiber 11 transmits the laser beam required for projection. An optical fiber actuator 12 drives the optical fiber 11 to scan within a first plane, projecting the laser beam transmitted by the optical fiber 11 onto a galvanometer 13 (which can also be called a scanning mirror). The galvanometer 13 can scan around a first axis and reflect the laser beam onto a predetermined area to form a projected image. That is, the scanning direction of the galvanometer 13 is perpendicular to the scanning direction of the optical fiber 11. Figure 1 In the process, the first plane scanned by the optical fiber 11 is the paper surface, the first axis of the reciprocating rotation of the galvanometer 13 is inside the paper surface, and the galvanometer 13 scans inside and outside the paper surface.

[0050] The fiber optic actuator 12 can be a piezoelectric actuator, which can be placed inside a base. Typically, the fiber optic cable 11 can be cantilevered and mounted on the surface of the fiber optic actuator 12, meaning that the light-emitting end 112 of the fiber optic cable 11 is suspended outside the actuator, while the light-receiving end 111 can be coupled to the laser emitter to receive the laser beam. The driving circuit of the actuator 12 provides the driving signal for the actuator 12, enabling the actuator to vibrate at a set operating frequency, further driving the fiber optic cable to vibrate and scan in a plane.

[0051] The galvanometer 13 can be a MEMS-driven galvanometer, which includes a reflector. Under external drive, the reflector can reciprocate around an axis at a set frequency. The reflector can be connected to the rotating shaft in different ways, such as being placed in a frame with a rotating shaft and rotatably fitted onto a rotating shaft. The galvanometer 13 and the fiber optic actuator 12 can share a unified external circuit. This external drive circuit provides different drive signals so that the two have different operating frequencies.

[0052] The laser beam projected by the optical fiber 11 can always be monochromatic, achieving a monochromatic projected image. Alternatively, time-division multiplexing can be used to change the intensity and color of the laser beam projected by the optical fiber 11 in time intervals according to the image information to be displayed, so that the laser beam projected by the optical fiber 11 matches the laser color and intensity at a specific projection point at a specific time. Another method for color projection is to use an RGB single-mode optical fiber, directly projecting the mixed beam at the RGB light source input section for each pixel. When the beam exits at the output end of the optical fiber 11, interference and divergence are inevitable, affecting the image quality. After the beam is reflected by the galvanometer 2, the optical path can be adjusted to form an image on the desired imaging surface.

[0053] When the light beam exits through the output end 112 of the optical fiber 11, it is inevitably subject to interference. Therefore, in order to improve the imaging quality, an optical component, such as a lens, can be set in the optical path so that the light beam emitted from the output end 112 of the optical fiber can be adjusted. At the same time, it is necessary to minimize the volume and size of the entire laser scanning device as much as possible without affecting the imaging quality, so as to meet the miniaturization requirements of the application products.

[0054] Please refer to Figure 2 This is a schematic diagram of a laser scanning device provided in an embodiment of this application. In this embodiment, the device includes an optical fiber actuator 22, a lens 23, and a galvanometer assembly 24: the optical fiber actuator 22 is connected to an optical fiber 21 and drives the optical fiber 21 to vibrate and scan on a first plane (fast axis plane) at a first working frequency under the drive of an external signal. An external laser beam passes through the optical fiber and enters the lens 23. The lens 23 is located at a set position between the galvanometer assembly 24 and the light-emitting end 212 of the optical fiber 21.

[0055] The galvanometer assembly 24 includes a reflecting mirror 241 with a first tilt angle. Under external drive, the reflecting mirror 241 can rotate and vibrate at a second operating frequency around the axis (slow axis) of the first plane or parallel to the axis of the first plane, projecting and reflecting the light emitted from the lens onto a preset area to form an image. The scanning trajectory of the fiber optic actuator and the scanning trajectory of the galvanometer assembly correspond to the rows and columns on the image.

[0056] The lens 23 is located between the fiber actuator 22 and the galvanometer assembly 24. At least one of its light-incident surfaces faces the light-out end 212 of the fiber 21, and its light-out surface faces the reflector 241. The positional relationship between the lens 23, the fiber 21, and the galvanometer assembly 24 is determined by the first tilt angle, the characteristic parameters of the lens 23, and the size of the reflector 241.

[0057] The positional relationship between the lens and the galvanometer assembly is determined by the first tilt angle, the characteristic parameters of the lens, the parameters of the optical fiber, and the size of the reflecting mirror.

[0058] The laser scanning device provided by the above embodiments can achieve decoupling of fast-axis and slow-axis vibration. The fiber optic fast-axis drive can be directly driven by the resonant frequency, eliminating the need to design complex matching relationships between the fiber characteristic frequency, actuator characteristic frequency, and drive frequency, thus avoiding nonlinearity. Fast-axis scanning is achieved with extremely low drive voltage. This greatly increases the robustness of device parameters and significantly reduces manufacturing requirements. Furthermore, when the fiber optic actuator uses piezoelectric one-dimensional high-frequency scanning, the high-frequency vibration component has extremely low vibration inertia. Compared with MEMS high-frequency galvanometers, this reduces processing requirements, lowers drive power consumption, and improves fatigue resistance. In an optional embodiment, the laser scanning device provided by this application may also include a microcircuit to provide the drive signal for the fiber optic actuator 22. It may also simultaneously provide the drive signal for the galvanometer assembly 24 via different adjustment units, making the operating frequency of the fiber optic actuator 22 much higher than the operating frequency of the galvanometer assembly 24 by an order of magnitude.

[0059] In an optional embodiment, the fiber optic actuator 22 in the laser scanning device provided in this application is a piezoelectric actuator, which can be composed of two crystal wafers. The vibration of the two crystal wafers provides the vibrational power to drive the connected optical fiber. This fiber optic actuator can be mounted on a base made of a heating material such as alumina ceramic. Figure 3 As shown, this allows for heating to compensate for temperature drift when the external ambient temperature changes.

[0060] In one embodiment, the optical fiber 21 can be cantilevered and fixed to the surface of the optical fiber actuator 22, with its light-emitting end 212 at a predetermined distance from the tail of the optical fiber actuator 22. This allows the part of the optical fiber 21 with its light-emitting end 212 to vibrate along the first plane, forming a directional light scan. The optical fiber can be cylindrical, and its light-emitting end 212 can be cylindrical or conical, without limitation.

[0061] Please also refer to Figure 2 and Figure 3 The galvanometer assembly 24 in this embodiment may include a coil, a magnet, a flexible hinge, and a reflective lens. The coil can receive external signals for driving. After being energized, it generates magnetic force, which in turn drives the magnet. The magnet drives the flexible hinge connected to it, which in turn drives the reflective lens connected to the hinge to periodically reciprocate around an axis. The magnet may be a permanent magnet, or a set of two sets of permanent magnets arranged side by side. When the magnet contains two sets of flat permanent magnets, a greater deflection force can be generated under the same magnetic field strength generated by the coil. In this case, the adjacent positions of the two sets of side by side permanent magnets have opposite polarities. Preferably, the first-order rotational vibration resonant frame rate of the galvanometer assembly 24 is >200Hz and <2000Hz to ensure image stability and keep the driving current at a low level.

[0062] In one embodiment, the reflective lens has a first tilt angle, enabling a 90-degree turn in the light output, thus better adapting to the flexible installation requirements of applications such as AR glasses. The reflective lens can be elongated (e.g., rectangular, elliptical), with a size slightly larger than the trajectory of the fast axis on the lens. Since the galvanometer assembly only needs to reflect the one-dimensional trajectory of the fast axis, the width of the reflective lens can be reduced to only slightly larger than the beam diameter, thereby reducing the lens width and lowering the product size compared to implementations that reflect a two-dimensional trajectory. Because the light irradiates the reflective lens in a linear scanning trajectory, the problems of high energy density and easy ablation associated with focused laser beams are solved.

[0063] In one possible implementation, the reflector 241 is a semi-reflective mirror. In this implementation, a portion of the light rays that enter the reflector 241 after being imaged by the lens can pass through the reflector 241. When a photoelectric sensor is provided behind the galvanometer assembly 241, the photoelectric sensor realizes closed-loop control of the fast axis vibration by sensing the light rays.

[0064] In the aforementioned embodiments, a lens 23 is provided at a predetermined position between the 21-degree light-emitting end 212 of the optical fiber and the galvanometer assembly 24. This lens has an incident surface and an exit surface. To ensure that the overall size of the product is reduced as much as possible without affecting imaging quality, in one embodiment of this application, the positional relationship between the lens, the optical fiber, and the galvanometer is determined by the first tilt angle, the characteristic parameters of the lens, and the size of the reflecting mirror.

[0065] like Figure 6 As shown, the final assembly drawing of the scanner is as follows: Figure 6 As shown, after the laser is coupled into the optical fiber, it is sent to the lens via one-dimensional vibration scanning of the fiber. The lens sends the imaged one-dimensional laser trajectory to the galvanometer, and after reflection by the galvanometer, the image can be emitted from the side window.

[0066] In this embodiment, the lens parameters include focal length f, object-side numerical aperture NA, object height h, and a first tilt angle θ for the reflecting mirror. In one embodiment, the positional relationship between the lens, the optical fiber, and the galvanometer includes the entrance pupil position of the reflecting mirror and the optical distance l between the reflecting mirror and the optical distance l between the entrance pupil position and the optical distance l between the reflecting mirror and the center point of the reflecting mirror. The entrance pupil position of the galvanometer assembly is the position where the field rays of the trajectory formed by the optical fiber after scanning intersect in space after passing through the lens.

[0067] The entrance pupil position of the reflecting mirror and the optical distance l of the reflecting mirror are obtained in the following manner:

[0068]

[0069] The lens parameters also include a lateral imaging field of view of α and a longitudinal imaging field of view of β, assuming that the optical distance between the entrance pupil position of the reflecting lens and the reflecting lens is l; the relationship between the width W and height H of the reflecting lens and the lens parameters and the first tilt angle θ is as follows:

[0070]

[0071] Furthermore, assuming the distance from the fiber oscillation initiation point to the fiber optic output end face is r, the distance l' between the entrance pupil position of the reflecting mirror and the image-side principal plane of the lens is:

[0072]

[0073] The distance L between the reflecting mirror 241 of the galvanometer assembly 24 and the image-side principal plane of the lens is the sum of the distance l' between the entrance pupil position of the reflecting mirror and the image-side principal plane of the lens, and the optical distance l between the entrance pupil position of the reflecting mirror and the reflecting mirror. When the entrance pupil position is behind the galvanometer along the direction of light propagation, l is a negative value; when the entrance pupil position is in front of the galvanometer along the direction of light propagation, l is a positive value.

[0074] L=l+l′

[0075] Furthermore, the relationship between the distance L of the galvanometer reflecting mirror from the image-side principal plane of the lens and the lens parameters, the size of the reflecting mirror, and the first tilt angle is as follows:

[0076]

[0077] Furthermore, such as Figure 10 As shown, assuming the distance L between the galvanometer reflecting lens 241 and the image-side principal plane of the lens is equal to the distance l between the image-side principal plane of the lens and the last light-emitting surface of the lens. H’ satisfy:

[0078]

[0079] Among them, H m H represents the outer frame dimensions of the galvanometer. l It refers to the external dimensions of the reflective lens.

[0080] The width of the galvanometer can be expressed as:

[0081]

[0082] Based on the design requirements for assembly size, power consumption, and reliability, the galvanometer area A is less than 20mm². 2 Then, the relationship between the entrance pupil position of the reflecting lens and the maximum optical distance l of the reflecting lens, the area A and height h of the reflecting lens, the first tilt angle θ and the lateral field of view α of the reflecting lens, is as follows: At this time, the entrance pupil position of the reflecting lens and the optical distance l of the reflecting lens are at their maximum values:

[0083]

[0084] In an optional embodiment of the present invention, the galvanometer assembly is subject to the following two constraints:

[0085] To ensure good imaging quality and efficient light energy utilization, the laser scanning device as a whole needs to have a reasonable structural layout, and it must meet the following requirements:

[0086] 1. The numerical aperture (NA) of optical fiber is typically greater than 0.16.

[0087] 2. If the lateral field of view α is less than 60 degrees and the object size h is generally greater than 0.6 mm, then the lens focal length f is generally greater than 0.52 mm.

[0088] 3. The first tilt angle θ is generally between 30 and 60 degrees;

[0089] At the minimum focal length and maximum tilt angle, the reflector size H is the smallest. Therefore, the corresponding reflector height H needs to be greater than 0.195mm, and the reflector width W needs to be less than 102.5mm. However, due to structural limitations, preferably, W is less than 15mm. Since the reflector width W is greater than H*sin(θ), the reflector width W is greater than 0.168mm.

[0090] Similarly, it can be deduced that the height H of the reflecting mirror is less than... When the first tilt angle θ equals 30 degrees, the maximum value of the reflector height H is 6.32 mm; when the first tilt angle θ equals 60 degrees, the maximum value of H is 4.805 mm. Based on the optical fiber's numerical aperture, it can be calculated that when the first tilt angle is 30 degrees, the maximum focal length f of the lens is 9.875 mm; when the first tilt angle θ equals 60 degrees, the maximum focal length f is 12.84 mm. At a tilt angle of 60 degrees, the minimum lateral field of view α is 3.57 degrees.

[0091] As can be seen from the previous equation, when the height H of the reflecting mirror is at its minimum and the lateral field of view α is small, the optical distance l between the entrance pupil position of the reflecting mirror and the reflecting mirror can reach its maximum value. According to the above analysis, since decreasing f can decrease H, but will increase α, for the same object size, the height H of the reflecting mirror and the lateral field of view α cannot reach their minimum simultaneously. The above equation can be transformed into a relationship between the object size h and the focal length f:

[0092]

[0093] like Figure 11 As shown, the following results can be obtained through calculation, showing that the optical distance between the entrance pupil position of the reflecting lens and the reflecting lens is l, and the maximum distance is 82mm.

[0094] In other words, in the preferred embodiment of this application, the optical distance l between the entrance pupil position of the reflecting lens and the reflecting lens is less than or equal to 82 mm. When this condition is met, the overall size of the laser scanning device can be kept to a minimum without affecting the imaging quality of the lens.

[0095] The following calculation, based on a set of parameters satisfying the above constraints, estimates the range of distances from the entrance pupil of the galvanometer in the above structure to the last surface of the lens.

[0096]

[0097]

[0098] Based on the calculation logic in the previous embodiment, it can be known from the above structure that the distance between the entrance pupil of the galvanometer and the last surface of the lens is in the range of [1.5-1.7869, 1.5+1.7869].

[0099] In another embodiment, the lens can also be positioned between the light-emitting direction of the reflecting mirror and the projection area. However, there are problems with placing the lens behind the galvanometer:

[0100] like Figure 7As shown, for a hybrid scanning system using fiber optics and a galvanometer, the overlap positions of the emitted light from each field of view in the x and y directions are inconsistent. The x-direction, which is the fiber scanning direction, approximately overlaps with the fiber optic starting point, while the y-direction overlaps with the galvanometer scanning direction. The entire system can be equivalently represented as the following optical imaging system:

[0101] If the lens is placed behind the optical fiber and galvanometer, the following problems arise.

[0102] In the lens design process, the choice of aperture stop is unconventional. If a single aperture stop is used, it will be an irregularly shaped aperture stop, which will inevitably have a very small F-number in a certain direction. However, for a single field of view, the output value of the aperture is the same in both directions, so the design result is difficult to accurately assess the actual situation. If a dual aperture stop is used, the difference between the design result and actual use can be resolved. However, in either case, the entire optical system is a non-rotationally symmetric system, which makes the design extremely difficult.

[0103] like Figure 8 As shown, the galvanometer reflection position and the fiber optic oscillation position are located on both sides of the object surface, resulting in an irregular object surface. Analyzing the light propagation direction of the entire system, we can conclude that the object surface distribution during lens design is as follows: It can be seen that the object surface in the x and y directions bends in two directions. Therefore, the optical system needs to have opposite field curvatures in the two directions for correction. This cannot be satisfied by global or aspherical lenses. Therefore, cylindrical, double R-surface, or other freeform surfaces need to be used for correction, which will greatly increase the design and assembly difficulty.

[0104] When applied to AR systems, the inconsistency between the entrance pupil positions in two directions leads to significant differences in the exit pupil positions. Since the entrance pupil positions in the two directions are some distance apart, and because the focal length of imaging lenses is generally small, the exit pupil positions in the two directions may deviate considerably. When coupled into a waveguide, the coupling region needs to be expanded in one direction. The increased coupling size has a significant impact on the light transmission path and light energy utilization of the waveguide.

[0105] In the preceding embodiments, if the lens is placed between the galvanometer assembly and the fiber optic output end face, the imaging lens only needs to consider imaging in the X direction. Therefore, the three issues mentioned above can be addressed: During lens design, only X-direction imaging needs to be considered, so its aperture stop can be circular, and the F-number can match the numerical aperture of the fiber optic output, resulting in a reliable design. Because only imaging of the object on the x-axis is required, it can be designed as a rotationally symmetric optical system. Treating it as a rotationally symmetric optical system requires that the field curvature correction of the optical system be consistent across all angles, greatly reducing design and assembly difficulty. Since the exit pupil in the Y direction is located at the galvanometer vibration position, the distance difference between the exit pupil position in the X direction and the galvanometer vibration position can be small through the optical system. Therefore, only a small extension in a certain direction is needed when coupling into the waveguide, such as... Figure 9 As shown.

[0106] This application also provides an electronic device that includes the preceding embodiments. The provided laser scanning device, in one embodiment, can be applied to augmented reality (AR) glasses. The laser projection device is disposed within the frame of the AR glasses, allowing the user to conveniently project images for viewing while wearing the glasses. Alternatively, in another embodiment, the laser scanning device can be disposed within the probe of an endoscope, using the endoscope to emit and collect optical signals into a confined space. Alternatively, the laser projection system can be a mobile phone, with the laser projection device embedded within it. Alternatively, the laser projection system can be a watch, with the laser projection device embedded within the watch face or strap.

[0107] The solutions in this application can be applied to electronic devices, including but not limited to electronic devices with data processing capabilities.

[0108] Reference Figure 12 The diagram shows a structural schematic of an electronic device according to another embodiment of the present application. The specific embodiments of the present application do not limit the specific implementation of the electronic device. The electronic device may be an endoscope, augmented reality glasses, an endoscope, a vehicle-mounted device, etc.

[0109] like Figure 12 As shown, the electronic device may include: a processor 402, a communications interface 404, a memory 406 storing a program 410, and a communications bus 408, and may also include any embodiment of the laser scanning device provided in the preceding embodiments of this application.

[0110] The processor, communication interface, and memory communicate with each other via a communication bus. The communication interface is used to communicate with other electronic devices or servers. The processor executes programs, specifically the steps described in the method embodiments above. Specifically, the program may include program code, which includes computer operation instructions.

[0111] The processor may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The one or more processors included in the smart device may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs.

[0112] Memory is used to store programs. Memory may include high-speed RAM, and may also include non-volatile memory, such as at least one disk drive.

[0113] The above descriptions are merely illustrative embodiments of this application and are not intended to limit the scope of the embodiments of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the embodiments of this application should fall within the protection scope of the embodiments of this application.

[0114] It should be understood that although this specification describes various embodiments, not every embodiment contains only one independent technical solution. This descriptive method is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0115] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0116] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0117] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0118] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0119] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, a network interface, and memory. Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0120] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0121] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0122] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0123] This application can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific transactions or implement specific abstract data types. This application can also be practiced in distributed computing environments where transactions are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

Claims

1. A laser scanning device, characterized in that, The device includes an optical fiber actuator, a lens, and a galvanometer assembly. The fiber actuator is connected to an optical fiber and, under the drive of an external driving signal, drives the optical fiber to vibrate and scan on a first plane at a first working frequency. An external laser beam forms a linear scanning trajectory after passing through the optical fiber and enters the lens. The lens is located at a predetermined position between the fiber actuator and the galvanometer assembly, with at least one light-incident surface facing the light-out end of the fiber and its light-out surface facing the reflective mirror included in the galvanometer assembly. The reflective lens has a first tilt angle and can rotate and vibrate at a second operating frequency around an axis parallel to the first plane under external drive, reflecting the light emitted from the lens to a preset area to form an image.

2. The laser scanning device as described in claim 1, characterized in that, The positional relationship between the lens and the galvanometer assembly is determined by the first tilt angle, the characteristic parameters of the lens, the parameters of the optical fiber, and the size of the reflecting mirror.

3. The laser scanning device as described in claim 1, characterized in that, The optical distance between the entrance pupil position of the reflecting lens and the reflecting lens is less than or equal to 82mm. The position where the field rays of each field of view that form the trajectory after the fiber scanning intersect in space after passing through the lens is the entrance pupil position of the galvanometer.

4. The laser scanning device as described in claim 1, characterized in that, The lens includes at least two sets of lenses, wherein the distance between the center point of the light-emitting surface of the last set of lenses and the center point of the reflecting lens is determined by the first tilt angle, the characteristic parameters of the lens, and the size of the reflecting lens.

5. The laser scanning device as described in claim 4, characterized in that, The relationship between the entrance pupil position of the reflecting lens and the optical distance l of the reflecting lens, and the relationship between the width W and height H of the reflecting lens and the lens parameters and the first tilt angle, is as follows: Where f is the focal length of the lens, NA is the object-side numerical aperture NA of the lens, h is the object-side dimension h of the lens, and θ is the first tilt angle of the reflecting mirror.

6. The scanning device as described in claim 5, characterized in that, The distance from the optical fiber's starting point to its output end face is r, and the distance ll' between the entrance pupil of the reflecting mirror and the image-side principal plane of the lens is:

7. The scanning device as claimed in claim 6, characterized in that, The distance L between the galvanometer reflecting lens and the image-side principal plane of the lens is the sum of the distance l' between the entrance pupil position of the reflecting lens and the image-side principal plane of the lens, and the optical distance l between the entrance pupil position of the reflecting lens and the reflecting lens. When the entrance pupil position is behind the galvanometer along the direction of light propagation, l is a negative value; when the entrance pupil position is in front of the galvanometer along the direction of light propagation, l is a positive value. L＝l+l′ The relationship between the distance L between the galvanometer reflecting mirror and the image-side principal plane of the lens, the lens parameters, α (lateral field of view), the size of the reflecting mirror, and the first tilt angle θ is as follows:

8. The apparatus as claimed in claim 7, characterized in that, The distance L between the galvanometer reflecting lens and the image principal plane of the lens is equal to the distance l between the image principal plane of the lens and the last surface of the lens. H’ : Among them, the H of the galvanometer m Outer frame dimensions, H l β is the external dimensions of the reflecting mirror, and β is the longitudinal field of view.

9. The laser scanning device as described in claim 8, characterized in that, The size of the reflecting mirror is less than 20mm². 2 .

10. The apparatus as claimed in claim 9, characterized in that, The entrance pupil position of the reflecting lens and the optical distance l of the reflecting lens are obtained in the following manner:

11. The laser scanning device as claimed in claim 1, characterized in that, The reflective lens is a semi-reflective mirror, which allows a portion of the light entering the reflective lens to pass through and enter a photoelectric sensor. The photoelectric sensor generates a feedback signal based on a portion of the optical fiber changes, which is used to adjust the driving parameters of the optical fiber actuator.

12. An electronic device, characterized in that, Includes the laser scanning device according to any one of claims 1-11.

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