Laser projection equipment, focusing method and storage medium

Abstract

The embodiment of the invention provides laser projection equipment, a focusing method and a storage medium, and relates to the technical field of projection. The laser projection equipment comprises a projection lens and a control device. The projection lens comprises a lens barrel and a lens located in the lens barrel. The control device is configured to obtain a first distance in response to a focusing instruction, and the first distance is the distance between the projection lens and the projection medium at the current moment; determining a focusing adjustment parameter of the lens based on the first distance, wherein the focusing adjustment parameter indicates the position of the lens when the image projected by the laser projection equipment is clearest; and driving the lens barrel to rotate based on the focusing adjustment parameter so as to drive the lens to move to a position indicated by the focusing adjustment parameter. Therefore, according to the first distance, the position of the lens when the image projected by the laser projection equipment is clearest can be directly determined, and then focusing is performed based on the position, so that the focusing efficiency is improved.

Description

Laser projection equipment, focusing method and storage medium

[0001] This application claims priority to Chinese patent application No. 202311154289.8 filed on September 7, 2023, entitled “Laser Projection Equipment and Autofocus Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of projection technology, and in particular to a laser projection device, a focusing method and a storage medium. Background Art

[0003] Laser projection equipment projects laser light through the optical lens assembly within the projection lens onto a projection medium (such as a screen or curtain) to form an image. During the projection process, to ensure image clarity, a certain distance must be maintained between the projection lens and the projection medium to accommodate the focal length requirements of the optical lens assembly. This requires adjusting the focal length of the optical lens assembly, known as focusing.

[0004] In the related art, the optical lens assembly includes a lens. When the laser projection device is focusing, the stepper motor drives the barrel of the projection lens to rotate to move the lens and determine the clarity of the projected image. If the currently projected image is not the clearest, the stepper motor continues to drive the barrel to rotate. In order to find the clearest focus position (that is, the projected image is the clearest), it is necessary to control the barrel to rotate back and forth multiple times. Moreover, after finding the clearest focus position, the barrel will continue to be driven to rotate a short distance (called overshoot), and then rotate in the opposite direction to return to the clearest focus position to ensure the accuracy of focus. When the barrel stabilizes at the clearest focus position, the focusing process is completed, and at this time, the projected image will achieve the best clarity.

[0005] However, due to the return distance difference of the stepper motor itself, the above focusing process needs to be adjusted repeatedly many times, which is time-consuming and has low focusing efficiency.

[0006] Summary of the Invention

[0007] This application provides a laser projection device, a focusing method, and a storage medium, which can improve the focusing efficiency of the laser projection device. The technical solutions provided in this application are as follows:

[0008] In a first aspect, a laser projection device is provided, comprising: a projection lens and a control device, wherein the projection lens comprises a lens barrel and a lens located within the lens barrel; and the control device is configured to:

[0009] In response to a focus instruction, obtaining a first distance; wherein the first distance is the distance between the projection lens and the projection medium at a current moment;

[0010] Determining a focus adjustment parameter of the lens based on the first distance; wherein the focus adjustment parameter indicates a position of the lens when the image projected by the laser projection device is clearest;

[0011] Based on the focus adjustment parameter, the lens barrel is driven to rotate, so as to drive the lens to move to a position indicated by the focus adjustment parameter.

[0012] In a second aspect, a focusing method is provided, which is applied to a laser projection device, wherein the laser projection device includes: a projection lens and a control device; the projection lens includes a lens barrel and a lens located in the lens barrel; the method includes:

[0013] In response to a focus instruction, acquiring a first distance; the first distance being the distance between the projection lens and the projection medium at a current moment;

[0014] Determining a focus adjustment parameter of the lens based on the first distance; wherein the focus adjustment parameter indicates a position of the lens when the image projected by the laser projection device is clearest;

[0015] Based on the focus adjustment parameter, the lens barrel is driven to rotate, so as to drive the lens to move to a position indicated by the focus adjustment parameter.

[0016] In a third aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a control device, the focusing method as shown in the second aspect is implemented.

[0017] In a fourth aspect, a computer program product is provided. When the computer program product is run on a control device, the control device implements the focusing method shown in the second aspect above.

[0018] The beneficial effects of the technical solution provided by this application include at least:

[0019] Upon receiving a focus instruction, the control device in the laser projection device can directly determine the focus adjustment parameters of the lens based on the first distance between the projection lens and the projection medium. Since the focus adjustment parameters indicate the position of the lens when the image projected by the laser projection device is clearest, that is, based on the first distance, the present application can directly determine the position of the lens when the image projected by the laser projection device is clearest, and then move the lens to that position to complete the focus. Compared with the method of repeatedly taking pictures and analyzing the clarity in the related art, the present application greatly reduces the time consumed in the focusing process and improves the focusing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] FIG1 is a schematic diagram of a projection scene provided in an embodiment of the present application;

[0022] FIG2 is a schematic structural diagram of a laser projection device provided in an embodiment of the present application;

[0023] FIG3 is a circuit diagram of a light emitting component provided in an embodiment of the present application;

[0024] FIG4 is a schematic diagram of a projection light path provided in an embodiment of the present application;

[0025] FIG5 is a schematic diagram of the software architecture of a display control system of a laser projection device provided in an embodiment of the present application;

[0026] FIG6 is a schematic diagram of an implementation environment of a focusing method provided in an embodiment of the present application;

[0027] FIG7 is a schematic diagram of a method for measuring the distance between a projection lens and a projection medium provided by an embodiment of the present application;

[0028] FIG8 is a schematic flow chart of a focusing method provided in an embodiment of the present application;

[0029] FIG9 is a schematic diagram of the structure of a projection lens provided in an embodiment of the present application;

[0030] FIG10 is a schematic diagram of a protective area of ​​a reflective film provided in an embodiment of the present application;

[0031] FIG11 is a schematic structural diagram of a control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of this application more clear, the following will clearly and completely describe the implementation methods of the technical solutions provided by this application in conjunction with the accompanying drawings in the exemplary embodiments. Obviously, the exemplary embodiments described are only part of the embodiments of this application, not all of them.

[0033] Before explaining the focusing method provided in the embodiment of the present application, the structure and projection characteristics of the laser sensor are first introduced.

[0034] A projection device is a device that can project media data onto a projection medium. It can be connected to computers, broadcasting networks, the Internet, VCDs (Video Compact Discs), DVDs (Digital Versatile Disc Recordables), game consoles, DVs, and other devices through different interfaces to receive the media data to be projected. It then uses optical principles to amplify the media data signal and project it onto the projection medium to present a clear and bright image on the projection medium.

[0035] The media data to be projected includes, but is not limited to, any one or a combination of images, videos, and texts; and the projection medium includes, but is not limited to, walls, curtains, screens, etc. This embodiment of the application does not impose any restrictions on this.

[0036] It should be noted that the focusing method provided in the embodiments of the present application can be applied to various types of projection equipment, including but not limited to laser projection equipment. The embodiments of the present application only use laser projection equipment as an example to illustrate the focusing method provided in the embodiments of the present application, and do not constitute a limitation on the equipment to which the focusing method can be applied.

[0037] Please refer to Figure 1, which is a schematic diagram of an exemplary projection scenario provided by an embodiment of the present application. The projection scenario includes a projection medium 1 and a laser projection device 2. During projection, the projection medium 1 can be fixed in a first position, and the laser projection device 2 can be placed in a second position. The relative positional relationship between the first and second positions is then adjusted, i.e., the position of the laser projection device 2 relative to the projection medium 1 is adjusted, so that the image projected by the laser projection device 2 coincides with the projection surface of the projection medium 1.

[0038] Please refer to Figure 2, which is a schematic diagram of the structure of a laser projection device provided in an embodiment of the present application. The laser projection device may include: a laser light source 210, an optical engine 220, and a lens assembly 230. Among them, the laser light source 210 is used to generate a laser beam to provide illumination for the optical engine; the optical engine 220 is used to modulate the laser beam emitted by the laser light source 210, and convert it into an image signal suitable for projection, and output it to the lens assembly 230; the lens assembly 230 is used to image the image signal through the magnification and focusing effect of the lens to form a clear image, and project the image onto the projection medium. Finally, the projected image is presented by the projection medium for the user to watch.

[0039] In some embodiments, the laser light source 210 includes a laser assembly and an optical lens assembly. The laser beam emitted by the laser assembly can pass through the optical lens assembly, thereby providing illumination for the optical engine 220. The laser assembly may include at least one laser and an optical lens assembly. The laser is used to generate the laser beam, and the optical lens assembly is used to control and optimize the direction, size, shape, and focus of the laser beam. In addition, in some cases, the optical lens assembly also protects the internal components of the laser from contaminants such as dust and dirt. Therefore, regular cleaning and maintenance of the optical lens is also one of the important measures to maintain the stability and reliability of the laser light source.

[0040] In some embodiments, the optical engine 220 modulates and converts the laser beam. This engine incorporates a complex series of optical components, such as lenses, reflectors, and fluorescent materials. When the laser beam enters the optical engine 220, it is precisely processed and regulated by these optical components, converting it into an image signal suitable for projection.

[0041] In addition, the optical engine 200 also has functions such as color correction and brightness adjustment to ensure that the color of the projected image is accurate and the brightness is uniform.

[0042] As an example, the optical machine 200 may include a light source part and an optical system. The light source part specifically includes a blue light machine, a green light machine, and a red light machine, which correspond to the three primary color light sources in laser projection, respectively. They each generate high-brightness, high-purity blue, green, and red laser beams, which are precisely controlled and modulated inside the optical machine to form the desired projection image. Of course, the optical machine can also use LED (Light Emitting Diode) as a light source, and the embodiment of the present application is not limited to this. The optical system may include lenses, reflectors, etc., which are used to focus, expand, reflect, and modulate the light beam emitted by the light source part to ensure that the light beam can be projected onto the projection medium according to a predetermined path and shape.

[0043] In some embodiments, the optical engine 220 also includes a heat dissipation system and a circuit control system. The heat dissipation system typically includes components such as fans and heat sinks, which are used to dissipate heat from the laser projection device to prevent overheating and damage. The circuit control system, serving as the "brain" of the optical engine, is responsible for controlling the light source on and off, adjusting parameters such as the brightness, color, and shape of the light beam, and processing external image signals to convert them into optically projected images. The circuit control system typically includes key components such as a microprocessor, driver circuits, and signal processing circuits.

[0044] In some embodiments, the laser projection device further includes a mainboard, which includes at least one of a CPU (Central Processing Unit), a video processor, an audio processor, a GPU (Graphics Processing Unit), RAM (Random Access Memory), ROM (Read-Only Memory), first to nth interfaces for input / output, and a communication bus. The mainboard is connected to hardware related to the laser projection device, such as a display control circuit, a brightness sensor, a distance sensor, and an image acquisition device, and is used to control the laser projection device's functions such as projection, focusing, calibration, obstruction detection, obstruction prompts, and screen power status adjustment.

[0045] In some embodiments, the laser projection device may be provided with several types of interfaces, such as a power interface, a USB interface, an HDMI (High Definition Multimedia Interface), a network cable interface, a VGA (Video Graphics Array) interface, a DVI (Digital Visual Interface), etc., to connect a signal source for transmitting media data.

[0046] In some embodiments, upon startup, the laser projection device can directly access the display interface of the last selected signal source or the signal source selection interface. The signal source can be a pre-installed video-on-demand program, or a signal source such as an HDMI interface, a USB interface, or a live TV interface. After the user selects a target signal source, the laser projection device can acquire media data from the target signal source and project the media data onto the projection medium for display.

[0047] In some embodiments, the laser projection device may be configured with a camera for coordinated operation with the laser projection device to achieve regulation and control of the projection process. For example, the camera configured with the laser projection device may be specifically implemented as a 3D camera or a binocular camera. When the camera is implemented as a binocular camera, it may include a left camera and a right camera. The binocular camera can capture the image and playback content presented by the screen corresponding to the laser projection device, that is, the projection surface. This image or playback content is projected by the laser projection device's built-in optical engine.

[0048] When the laser projection device moves, its projection angle and distance to the projection surface change, causing the projected image to deform. The projected image will appear as a trapezoidal image or other deformed image. The laser projection device controller can achieve automatic trapezoidal correction based on the image captured by the camera by coupling the angle between the optical projection surfaces and the correct display of the projected image.

[0049] In addition, with respect to the laser projection device shown in FIG. 2 above, in some embodiments, since the laser light source 210, the optical machine 220, and the lens assembly 230 work together to project an image, the laser light source 100, the optical machine 200, and the lens assembly 230 may also be collectively referred to as a light output assembly.

[0050] Please refer to Figure 3, which is a circuit diagram of a light output component provided in an embodiment of the present application. The laser projection device may include: a display control circuit 310, at least one laser driving component 320, a laser light source 330, and at least one brightness sensor 340. The laser light source 330 may include at least one laser corresponding to the at least one laser driving component 320. The at least one refers to one or more, and the plurality refers to two or more.

[0051] The laser light source 330 may include a blue laser, a red laser, and a green laser. It should be understood that the laser light source 330 plays the same role as the laser light source 210 shown in FIG. 2 in the projection process, and both are used to generate laser beams.

[0052] In some embodiments, based on the light-emitting component shown in FIG3 , the laser projection device can also achieve adaptive adjustment of the brightness of the light source. That is, a brightness sensor is provided in the light-emitting path of the laser light source to detect the first brightness value of the laser light source, and the first brightness value is sent to the display control circuit. The display control circuit can obtain the second brightness value corresponding to the driving current of each laser, and when it is determined that the difference between the second brightness value of the laser and the first brightness value of the laser is greater than the difference threshold, it is determined that the laser has a COD (Catastrophic optical damage) failure. At this time, the display control circuit can adjust the current control signal of the laser drive component corresponding to the laser until the aforementioned difference is less than or equal to the difference threshold, thereby eliminating the COD failure of the laser. In this way, the laser projection device can eliminate the COD failure of the laser in a timely manner, reduce the damage rate of the laser, and improve the image display effect of the laser projection device.

[0053] Based on the laser light sources shown in Figures 2 and 3 above, please refer to Figure 4, which is a schematic diagram of a projection optical path provided in an embodiment of the present application. Among them, the laser light source may include independently arranged blue laser 211, red laser 212, and green laser 213. In the case where the laser light source includes a three-color light source, the corresponding laser projection device may also be referred to as a three-color laser projection device. In a specific implementation, the above-mentioned blue laser 211, red laser 212, and green laser 213 are all lasers packaged in MCL (Mirai Console Loader, module lightweight), which are small in size and conducive to the compact arrangement of the optical path.

[0054] Please refer to Figure 5, which is a schematic diagram of the software architecture of a display control system for a laser projection device provided in an embodiment of the present application. The laser projection device has the characteristics of a micro-projector with a long focal length, and the control device therein can control the display of the projected image through a preset algorithm program, etc., to achieve automatic keystone correction, automatic screen entry, automatic obstacle avoidance, automatic focus adjustment, and anti-glare protection for the projected image.

[0055] In some embodiments, the image acquisition device (e.g., camera) in the laser projection device collects image data and sends it to the camera service, which then sends the image data to the process communication framework and / or the correction service of the laser projection device. After the correction service receives the image data sent by the camera service, it calls the corresponding control algorithm in the algorithm library for the different functions that need to be implemented. Furthermore, through the process communication framework and data interaction with the application service, the process communication framework feeds back the calculation results to the correction service, which sends the calculation results to the operating system of the laser projection device to generate control signaling, and sends the control signaling to the optical machine control driver to control the optical machine working conditions, thereby achieving automatic correction of the projected image.

[0056] In some embodiments, the laser projection device is equipped with a gyroscope sensor; when the laser projection device moves, the gyroscope sensor can sense the position movement and actively collect movement data; the collected movement data is then sent to the application service layer through the system framework layer to support data calls during user interface interaction and application interaction.

[0057] After introducing the structure and projection characteristics of the laser projection device in conjunction with Figures 1-5, the application background involved in the embodiments of the present application will be introduced next.

[0058] As previously mentioned, laser projection equipment projects laser light through the optical lens assembly within a projection lens onto a projection medium to form an image. However, to ensure image clarity, a certain distance must be maintained between the projection lens and the projection medium to accommodate the focal length requirements of the optical lens assembly, which includes the lens elements. This means that the focal length of the optical lens assembly, known as focusing, must be adjusted during projection.

[0059] In the related art, when a laser projection device is focusing, the projection lens is driven by a stepper motor to rotate left and right (or up and down) according to the current position of the projection lens. After each rotation, the clarity of the image projected by the laser projection device is judged. Based on the judgment result of the clarity, the next movement direction of the projection lens is determined. If the image projected at the current position is not the clearest, the projection lens will continue to be driven by the stepper motor to rotate in a certain direction. In order to find the clearest focus position (that is, the projected image is the clearest), it is necessary to control the projection lens to perform multiple reciprocating movements, and re-evaluate the clarity of the projected image after each new position is reached. After a certain position is determined to be the clearest focus position, the projection lens will continue to be driven forward for a short distance (called overshoot), and then move in the opposite direction to return to the clearest point to ensure the accuracy of focus. When the projection lens stabilizes at the clearest point, the focusing process is completed, and at this time, the projected image will achieve the best clarity.

[0060] During the reciprocating motion of the projection lens, due to the mechanical characteristics of the stepper motor and gears, each time the lens moves from the same position in the opposite direction, the actual position reached may deviate due to factors such as friction and clearance. This deviation is called "backlash." Due to the inherent backlash of the stepper motor, the focus algorithm may not accurately identify the true sharpest focus position. To more accurately find the sharpest focus position, the focus algorithm needs to continuously evaluate the clarity of the projected image and adjust the position of the lens barrel based on the evaluation results. This may require multiple evaluations to determine the sharpest focus position.

[0061] As can be seen from this, the return distance difference of the stepper motor makes it difficult for the focus algorithm to determine the focus position. As the number of focus algorithm operations increases, the entire focus process takes longer and the focus efficiency decreases. In addition, frequent operations also increase the energy consumption and heat generation of the laser projection equipment itself.

[0062] Based on this, an embodiment of the present application provides a focusing method that, in response to a focus instruction, directly determines the focus adjustment parameter of the lens based on the first distance between the projection lens and the projection medium. Because the focus adjustment parameter indicates the position of the lens when the image projected by the laser projection device is clearest, the embodiment of the present application can directly determine the position of the lens when the image projected by the laser projection device is clearest based on the first distance, and then directly move the lens to that position to complete focusing. Compared to the method of repeatedly taking pictures and analyzing clarity in the related art, the embodiment of the present application greatly reduces the time consumed in the focusing process and improves focusing efficiency.

[0063] Next, the implementation environment of the focusing method provided in the embodiment of the present application is introduced.

[0064] Referring to Figure 6 , the laser projection device may include a projection lens 65 and a control device (not shown). The projection lens 65 includes a lens barrel and a lens located within the lens barrel. The control device is configured to execute the focusing method provided in the embodiments of the present application to adjust the position of the lens so that the image projected by the laser projection device meets the required clarity.

[0065] In some embodiments, as shown in FIG6 , the laser projection device further includes: a main board 61 , a display panel 62 , a light valve 63 , a laser light source 64 , a distance sensor 66 , and a lens adjustment assembly 67 .

[0066] In a possible implementation, the control device may be included in the above-mentioned main board 61 to participate in executing the focusing method provided in the embodiment of the present application.

[0067] Among them, the main board 61 is connected to the display panel 62 and is configured to: send the image signal to the display panel 62; the display panel 62 is connected to the light valve 63 and is configured to: generate a light valve control signal according to the image signal, and control the flipping of the light valve 63 according to the light valve control signal to transmit the laser light beam emitted by the laser light source 64 to the projection lens 65; the projection lens 65 is configured to: project the laser beam into an image.

[0068] In some embodiments, the lens adjustment assembly 67 is connected to the mainboard 61 and the projection lens 65, and is configured to drive the lens in the projection lens to move. For example, the lens adjustment assembly 67 can drive the projection lens 65 to move according to an adjustment instruction sent by the mainboard 61.

[0069] As an example, the lens adjustment assembly 67 may further include a driving device such as a DC motor to drive the projection lens to rotate, thereby driving the lens therein to move. This embodiment of the present application does not impose any limitation on this.

[0070] In some embodiments, the lens adjustment assembly 67 can be deployed independently or integrated into the projection lens 65, and this embodiment of the present application does not limit this.

[0071] In some embodiments, the mainboard 61 and the display panel 62 may be connected via an IIC (Inter-Integrated Circuit, also known as an I2C bus), and the mainboard 61 may send a video image signal to the display panel 62 via the I2C.

[0072] The mainboard 61 and the display panel 62 can transmit signals via the I / O port. For example, the display panel 62 can notify the mainboard 10 via the I / O port whether it has entered standby mode. The display panel 62 is also connected to a light valve 63. The display panel 62 is configured to generate a light valve control signal based on the video image signal and control the flipping of the light valve 63 based on the light valve control signal. The laser light source 64 emits a laser beam that illuminates the light receiving surface of the light valve 63. The light valve 63 is controlled to transmit the beam emitted by the laser light source 64 to the projection lens 65, which magnifies the image and projects it onto the projection medium.

[0073] In some embodiments, the display panel 62 can generate a light valve control signal based on the pixel value of the pixel in the video image signal, and control the light valve 63 to flip according to the light valve control signal. The flipped light valve 63 can transmit the laser beam irradiated onto its surface by the laser light source 64 to the projection lens 65. The projection lens 65 is used to project the laser beam onto the projection medium, thereby displaying an image on the projection medium.

[0074] In some embodiments, the motherboard 61 may be a SoC (System on Chip) unit. A SoC is a dedicated integrated circuit that contains a complete system and all embedded software. The SoC may be an Android SoC, which may host multiple applications.

[0075] It should be noted that when the mainboard 61 executes the focusing method provided in the embodiments of the present application, in addition to basic audio and video codec functions, the mainboard 61 also processes and converts the reflected signal from the photoelectric switch, outputs a control signal, and precisely controls the lens position. In other words, during projection by the laser projection device, the mainboard 61 can run the computer program corresponding to the focusing method and call the relevant components to perform the corresponding operations to achieve focusing.

[0076] In some embodiments, the display panel 62, the light valve 63 and the laser light source 64 can be a DLPC (Digital Light Processing Chip, based on a digital light processing chip), and specifically DMD (Digital Micromirror Devices) can be used as the main key processing element to implement the digital optical processing process.

[0077] In some embodiments, the distance sensor 66 may be a Time-of-Flight (TOF) distance sensor, such as a TOF camera. The TOF distance sensor measures distance by continuously sending light pulses to a target object and receiving the light returning from the object with a sensor. The distance between the sensor and the target object is determined by detecting the round-trip (flight) time of the light pulses.

[0078] As an example, a TOF camera is typically composed of an illumination unit, an optical lens, an imaging sensor, a control unit, and a computing unit.

[0079] Among them, the irradiation unit is used to pulse-modulate the light source before emitting it, and the frequency of the modulated light pulse can be as high as 100MHz. Therefore, during the image capture process, the light source will be turned on and off thousands of times. Each light pulse is only a few nanoseconds long. The exposure time parameter of the TOF camera determines the number of pulses for each imaging. It should be noted that in order to achieve accurate measurement, the light pulses must be precisely controlled to have exactly the same duration, rise time, and fall time. Because even a small deviation of only one nanosecond (ns) can produce a distance measurement error of up to 15cm. Such a high modulation frequency and accuracy can only be achieved by using sophisticated LEDs or laser diodes. Generally, the irradiation light source uses an infrared light source that is invisible to the human eye.

[0080] Optical lenses focus reflected light and form an image on an optical sensor. However, unlike conventional optical lenses, a bandpass filter is added to ensure that only light with the same wavelength as the illumination source is allowed to enter. This is done to suppress incoherent light sources, reduce noise, and prevent overexposure of the sensor due to external light interference.

[0081] The imaging sensor, the core of a TOF camera, has a similar structure to a typical image sensor, but incorporates two or more shutters for sampling reflected light at different times. Therefore, the pixels of a TOF camera are much larger than those of a typical image sensor, typically around 100 μm. The control unit precisely synchronizes the light pulse sequence with the opening and closing of the chip's electronic shutter, reads out and converts the imaging sensor's charges, and directs them to the computation unit.

[0082] The computation unit is used to record an accurate depth map, which is typically a grayscale image where the value of each pixel represents the distance between the light-reflecting surface and the camera. To achieve better results, the grayscale image is usually calibrated first.

[0083] In the focusing method provided in the embodiment of the present application, the distance sensor 66 can collect the distance between the projection lens and the projection medium in real time before or during focusing.

[0084] As an example, referring to Figure 7, a distance sensor in a laser projection device 71 sends a light pulse to a projection medium 72. After receiving the light pulse, the projection medium 72 reflects the light pulse back toward the distance sensor. During this process, the distance sensor detects and records the round-trip time of the light pulse to determine the distance (denoted as L) between the projection lens and the projection medium.

[0085] After introducing the application background and implementation environment of the embodiment of the present application, the focusing method provided by the embodiment of the present application is explained in detail.

[0086] FIG8 is a flow chart of a focusing method provided in an embodiment of the present application. This method can be applied to a control device of a laser projection device, wherein the laser projection device includes a projection lens and a control device. The projection lens includes a lens barrel and a lens located within the lens barrel. As an example, the control device can be included in the mainboard shown in FIG6 above. As shown in FIG8 , the focusing method includes the following steps:

[0087] S801: In response to a focus instruction, obtain a first distance; wherein the first distance is the distance between the projection lens and the projection medium at a current moment.

[0088] That is, after the laser projection device receives the focus instruction, the control device can control the distance sensor to measure the distance and read the first distance from the distance sensor, that is, the distance between the projection lens and the projection medium of the laser projection device in the current position.

[0089] As an example, the way in which the laser projection device measures and obtains the first distance can refer to the distance measurement principle of FIG7 above, which will not be described in detail here.

[0090] In one possible embodiment, the focus instruction is automatically generated when a change in the position of the laser projection device is detected.

[0091] As an example, a gyroscope sensor in a laser projector can detect the position of the laser projector. For example, as the laser projector moves, the gyroscope sensor can sense changes in the laser projector's position in real time and transmit this information to a control device. This allows the control device to instantly generate a focus command upon determining a change in the laser projector's position.

[0092] In another possible embodiment, the focus command is issued by the user through a preset control method based on actual needs. For example, the user can issue a focus command to the laser projection device through a remote control connected to the laser projection device, or the user can directly issue a focus command to the laser projection device by waking up a voice assistant. The embodiment of the present application does not limit the implementation method of the user issuing the focus command.

[0093] S802. Determine a focus adjustment parameter of the lens based on the first distance; wherein the focus adjustment parameter indicates a position of the lens when the image projected by the laser projection device is clearest.

[0094] In an embodiment of the present application, the focus adjustment parameters determined based on the first distance include multiple situations, and when the content of the focus adjustment parameters is different, the implementation process of determining the focus adjustment parameters based on the first distance is also slightly different. Next, the various implementation methods of determining the focus adjustment parameters are introduced respectively.

[0095] In a first case, the focus adjustment parameter includes a target lens position, wherein when the lens is at the target lens position, the image projected by the laser projection device at the first distance is clearest.

[0096] Based on this, the implementation process of the above step S802 may be: based on the first distance, obtaining the target lens position from the first mapping relationship. The first mapping relationship is a mapping relationship between the projection distance and the lens position, and the projection distance refers to the distance between the projection lens and the projection medium.

[0097] In the second case, the outer wall of the lens barrel has a reflective film, and the reflectivity of different reflective positions on the reflective film varies. In this case, the focus adjustment parameter includes a target reflectivity. When the lens barrel is positioned at the position corresponding to the target reflectivity, the laser projection device projects the clearest image at the first distance.

[0098] In other words, the reflective film has a gradient reflectivity, meaning that different locations on the film reflect different intensities of light. When light strikes the reflective film, the intensity of the reflected light changes monotonically as the location on the film changes.

[0099] Based on this, the implementation process of the above step S802 may be: based on the first distance, obtaining the target reflectivity from the second mapping relationship, wherein the second mapping relationship is a mapping relationship between projection distance and reflectivity, and the projection distance refers to the distance between the projection lens and the projection medium.

[0100] In a third scenario, the outer wall of the lens barrel has a reflective film, and different reflective positions on the reflective film have different reflectivities. These different reflectivities correspond to different quantized values ​​of the electrical signal. In this case, the focus adjustment parameter includes the target quantized value of the electrical signal. When the lens barrel is positioned at the position corresponding to the target quantized value of the electrical signal, the laser projection device projects the clearest image at the first distance.

[0101] The quantized value of the target electrical signal may be a voltage value or a current value, which is not limited in the embodiment of the present application.

[0102] That is, the third case can also be understood as converting the reflectivity into a quantized value of an electrical signal on the basis of the second case to construct a third mapping relationship.

[0103] Based on this, the implementation process of the above step S802 may be: based on the first distance, obtaining the target electrical signal quantization value from the third mapping relationship. The third mapping relationship is a mapping relationship between the projection distance and the electrical signal quantization value, and the projection distance refers to the distance between the projection lens and the projection medium.

[0104] It should be noted that for the second and third cases mentioned above, the structure of the laser projection equipment needs to be improved, that is, a reflective film is attached to the lens barrel so as to monitor the reflectivity of different positions on the reflective film during the focusing process to determine the position of the lens barrel and thus determine the position of the lens.

[0105] For the above three situations, before the laser projection equipment leaves the factory, it needs to undergo multiple tests in advance, and the distance of the laser projection equipment relative to the projection medium needs to be continuously adjusted. Based on different projection distances, the position of the lens in the projection lens when the image projected by the laser projection equipment is clearest at each projection distance is determined, thereby constructing the above-mentioned first mapping relationship, second mapping relationship and third mapping relationship.

[0106] In other words, the first mapping relationship, the second mapping relationship and the third mapping relationship are pre-generated and stored in the laser projection device, so that the control device can call these mapping relationships to determine the focus adjustment parameters corresponding to the first distance when performing the focusing operation.

[0107] In some embodiments, to ensure the clearest projected image when the projection distance changes, the lens position needs to be adjusted, specifically to a target lens position that maximizes the image clarity. As the lens position changes, the target reflectivity and target electrical signal quantization value corresponding to that lens position also change. Therefore, when constructing a mapping relationship, a direct mapping relationship between the multiple parameters of "projection distance - lens position - reflectivity of the reflective film - electrical signal quantization value" can be generated, although this is not a limitation in the present embodiments.

[0108] S803 : Based on the focus adjustment parameter, drive the lens barrel to rotate, so as to move the lens to the position indicated by the focus adjustment parameter.

[0109] It should be understood that when the content of the focus adjustment parameters is different, the implementation method of adjusting the lens position is also different. Next, combining the three focus adjustment parameters shown in step S802 above, the implementation methods of adjusting the lens position in step S803 are introduced respectively.

[0110] In the first lens position adjustment scheme, the focus adjustment parameters include the target lens position. Accordingly, the implementation process of step S803 can be: obtaining the actual position of the lens at the current moment to obtain the actual lens position; driving the lens barrel to rotate based on the target lens position and the actual lens position to drive the lens to move from the actual lens position to the target lens position.

[0111] The actual lens position can be determined based on the first distance and the position of the lens after the last focus adjustment, which is not limited in this embodiment of the present application.

[0112] While driving the lens barrel to rotate, the distance between the projection lens and the projection medium is continuously detected by the distance sensor to determine the change information of the lens position. When it is determined that the lens has moved to the target lens position, it is considered that the lens has reached the ideal focus position, and the lens barrel rotation is stopped at this time.

[0113] In the second lens position adjustment scheme, the focus adjustment parameters include the target reflectivity. Accordingly, the implementation process of step S803 can be: obtaining the actual reflectivity of the reflective film at the current moment; driving the lens barrel to rotate based on the target reflectivity and the actual reflectivity to adjust the reflectivity of the reflective film to the target reflectivity.

[0114] The reflectivity of the reflective film varies at different locations, meaning that the reflectivity of the film to light changes monotonically. In other words, as the lens barrel rotates, the lens inside and the reflective film on the outer wall of the barrel also rotate. As the barrel rotates to different positions, the reflectivity of the light reflected by the reflective film also varies.

[0115] That is, when the first distance between the projection lens and the projection medium in the laser projection device is known, the position of the lens of the laser projection device under the best focusing effect is fixed in the lens barrel, and it is the rotation of the lens barrel that drives the movement of the lens, so the position of the lens barrel is also relatively fixed. In the embodiment of the present application, a reflective film whose reflectivity changes monotonically with position is provided on the outer wall of the lens barrel. In this way, by detecting the change in the reflectivity of the reflective film on the lens barrel at a fixed point, the rotation of the lens barrel can be determined, thereby determining the change in the position of the lens in the lens barrel.

[0116] Based on this, once the target reflectivity is determined, the lens barrel is driven to rotate according to the change in reflectivity on the reflective film, so as to rotate the lens barrel to a position where the reflectivity of the reflective film reaches the target reflectivity. At this point, the position of the lens in the lens barrel reaches the ideal focus position. This ideal focus position can also be considered the target lens position in the first lens position adjustment scheme mentioned above.

[0117] In the third lens position adjustment scheme, the focus adjustment parameters include the target reflectivity. Accordingly, the implementation process of step S803 can be: obtaining the target electrical signal quantization value corresponding to the target reflectivity; wherein different reflectivities of the reflective film correspond to different electrical signal quantization values; obtaining the electrical signal quantization value corresponding to the actual position of the lens at the current moment to obtain the actual electrical signal quantization value; and driving the lens barrel to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target quantization value.

[0118] That is, the third lens position adjustment scheme is based on the second lens position adjustment scheme, converting the reflectivity of the reflective film into an electrical signal quantization value, and then judging whether the lens is in the target lens position based on the change of the electrical signal quantization value.

[0119] With respect to the second and third lens position adjustment schemes described above, the process of obtaining the actual reflectivity and the actual electrical signal quantization value based on the reflective film on the lens barrel will be explained below.

[0120] In one exemplary embodiment, as shown in Figure 9, the projection lens includes a lens 91, a lens barrel 92, a DC motor 93, a reflective film 94, and a photoelectric sensor 95. In this embodiment of the present application, the control device can respond to a focus adjustment command by obtaining a first distance from the distance sensor and then, based on the first distance and a second mapping relationship, obtaining a corresponding target reflectivity. Simultaneously, the control device can obtain the current actual reflectivity of the reflective film from the photoelectric sensor. Based on the actual reflectivity and the target reflectivity, the DC motor 93 can then drive the lens barrel 92 to rotate, thereby moving the lens 91 and adjusting the position of the lens 91.

[0121] In this implementation, the present embodiment uses a DC motor as the power source to drive the lens barrel. Compared to the related art solution of using a stepper motor to drive the lens barrel, this eliminates the existence of return path error and improves focusing efficiency. Moreover, compared with stepper motors, DC motors are smaller and less expensive.

[0122] The photoelectric sensor is fixed and perpendicular to the axis of the lens barrel. As the lens barrel rotates, the reflectivity of the reflective film changes. The photoelectric sensor can detect this change in real time to determine the actual reflectivity, or the quantized electrical signal corresponding to the actual reflectivity.

[0123] It should be understood that photoelectric sensors are key components for achieving photoelectric conversion, converting various optical signals (such as infrared, visible, and ultraviolet radiation) into electrical signals. Photoelectric sensors can detect non-electrical quantities that directly cause changes in light quantity, such as light intensity, illuminance, radiation temperature measurement, and gas composition analysis. In the embodiments of the present application, a photoelectric sensor can emit light of a fixed intensity to detect changes in light intensity when the reflective film is in different positions.

[0124] Continuing with Figure 9, the reflective film is located on the outer wall of the lens barrel. As the barrel rotates, the reflective film rotates with it. Since the photoelectric sensor is fixed, the light it emits is reflected only at point A. Therefore, as the barrel rotates, the reflectivity of the reflective film at point A changes, and the intensity of the reflected light changes accordingly. Based on this, the photoelectric sensor can measure the reflectivity of the reflective film at the current moment—that is, the actual reflectivity—by emitting light.

[0125] Thus, in the embodiment of the present application, a DC motor is used to rotate the lens barrel with the reflective film during focusing. By driving the lens barrel to rotate, the reflective film is driven to rotate, thereby adjusting the actual reflectivity of the reflective film. Simultaneously, as the lens barrel rotates, the lens also moves within the lens barrel. Therefore, when the reflectivity of the reflective film changes, the position of the lens within the lens barrel also changes. Once the target reflectivity is determined, the lens barrel can be driven to rotate by the DC motor, and changes in the reflectivity of the reflective film can be monitored during rotation. When the reflectivity on the reflective film reaches the target reflectivity, the position of the lens within the lens barrel has reached the ideal focus position. The ideal focus position here can also be considered the target lens position in the first lens position adjustment scheme described above.

[0126] Furthermore, the photoelectric sensor may also directly convert the reflectivity into a quantized value of an electrical signal, thereby adjusting the lens to a target lens position based on changes in the quantized value of the electrical signal.

[0127] The quantized value of the electrical signal may be a voltage value or a current value, which is not limited in the present embodiment. For ease of understanding, the following description uses the quantized value of the electrical signal as an example, i.e., the target quantized value of the electrical signal is a target voltage value, and the actual quantized value of the electrical signal is an actual voltage value.

[0128] In one possible implementation, when the photoelectric sensor receives a control instruction (e.g., a lens barrel position detection instruction) sent by a control device, the implementation process of measuring the actual electrical signal quantization value may be: in response to the control instruction, emitting a first light ray toward the lens barrel; receiving a second light ray reflected by the first light ray through a reflective film; based on the second light ray, determining the actual electrical signal quantization value, and feeding back the actual electrical signal quantization value to the control device.

[0129] In some embodiments, a photosensor typically consists of a transmitter, a receiver, and a detection circuit. The transmitter can be a light-emitting diode (LED) that emits light of a fixed intensity, i.e., the first light beam. The receiver can be an NPN transistor, whose emitter receives light reflected from an emitter film, i.e., the second light beam. The intensity of the second light beam is measured, and a corresponding current is obtained based on the intensity of the second light beam. This current is then calculated with the resistance value in the detection circuit to obtain an actual voltage value (i.e., the actual quantized value of the electrical signal).

[0130] In some embodiments, the actual voltage value can be read by an ADC (Analog-to-Digital Converter). The ADC can be integrated into the control device or the photoelectric sensor, which is not limited in the present embodiment.

[0131] Thus, in the embodiment of the present application, a DC motor is used to rotate the lens barrel with the reflective film during focusing. By driving the lens barrel to rotate, the reflective film is driven to rotate, thereby adjusting the actual voltage value. Simultaneously, as the lens barrel rotates, the lens also moves within the lens barrel. Therefore, when the reflectivity of the reflective film changes, the calculated actual voltage value also changes, and the position of the lens within the lens barrel also changes. Once the target voltage value is determined, the lens barrel can be driven to rotate by the DC motor, and changes in the reflectivity of the reflective film can be monitored during rotation. These changes in reflectivity are converted into changes in voltage. When the actual voltage value determined based on the reflective film reaches the target voltage value, the position of the lens within the lens barrel has reached the ideal focus position. The ideal focus position herein can also be considered the target lens position in the first lens position adjustment scheme described above.

[0132] In the fourth lens position adjustment scheme, the focus adjustment parameters include the target electrical signal quantization value. Accordingly, the implementation process of step S803 can be: obtaining the electrical signal quantization value corresponding to the actual position of the lens at the current moment to obtain the actual electrical signal quantization value; driving the lens barrel to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target electrical signal quantization value.

[0133] Among them, the light signal obtained by reflecting light of fixed light intensity with different reflectivities can be measured by any measuring instrument, and the light signal can be converted into an electrical signal quantization value to obtain the electrical signal quantization value corresponding to the different reflectivities. Based on the target electrical signal quantization value, the lens barrel is driven to rotate to move the lens to the ideal focusing position.

[0134] It should be noted that the method for obtaining the quantized value of the electrical signal corresponding to the actual position of the lens at the current moment can refer to the third lens position adjustment solution described above, that is, determining the actual quantized value of the electrical signal based on the reflectivity of the reflective film on the lens barrel at the actual position of the lens at the current moment. Of course, other methods can also be used to obtain the actual quantized value of the electrical signal, and this embodiment of the present application is not limited thereto.

[0135] Based on the four lens position adjustment schemes described above, after determining the focus adjustment parameters—namely, the target lens position, target reflectivity, and target electrical signal quantization value—the lens barrel can be driven to rotate based on these adjustment targets. Regardless of the focus adjustment parameters, the logic behind the control device driving the lens barrel to rotate and adjust the lens position remains similar. Next, using the focus adjustment parameter as the target electrical signal quantization value as an example, the implementation process of driving the lens barrel to rotate based on the actual and target electrical signal quantization values ​​will be explained.

[0136] In some embodiments, adjusting the actual electrical signal quantization value to the target electrical signal quantization value, that is, adjusting the electrical signal quantization value at the reflectivity corresponding to the current lens position to the target electrical signal quantization value, so as to move the lens to the target lens position, may include the following three cases:

[0137] (1) If the actual quantization value of the electric signal is less than the target quantization value of the electric signal, the lens barrel is driven to rotate in a first direction, wherein the first direction is a direction in which the quantization value of the electric signal increases.

[0138] It should be noted that when the lens barrel rotates in a first direction, the current quantized value of the electrical signal is increased, and when the lens barrel rotates in a second direction, the current quantized value of the electrical signal is decreased. Therefore, after obtaining the actual quantized value of the electrical signal and the target quantized value of the electrical signal at the reflectivity corresponding to the current lens barrel position, the target quantized value of the electrical signal can be subtracted from the actual quantized value of the electrical signal to determine the direction of lens barrel rotation. At this point, the control device can issue a control signal based on the determined rotation direction to drive the lens barrel to rotate in the corresponding direction, thereby directly adjusting the actual quantized value of the electrical signal to the target quantized value of the electrical signal.

[0139] In some embodiments, during the lens barrel rotation process, the lens barrel rotation angle can be controlled based on the difference between the actual quantized value of the electrical signal and the target quantized value of the electrical signal. For example, if the difference is large, the lens barrel rotation angle can be larger; if the difference is small, the lens barrel rotation angle can be smaller. This embodiment of the present application is not limited to this.

[0140] That is, if the actual electrical signal quantization value is smaller than the target electrical signal quantization value, it indicates that the electrical signal quantization value under the reflectivity corresponding to the current lens barrel position is smaller than the target electrical signal quantization value. The lens barrel needs to be rotated to increase the electrical signal quantization value to reach the target electrical signal quantization value in order to drive the lens to the ideal focusing position. At this time, the lens barrel is driven to rotate in the first direction until the electrical signal quantization value at the lens barrel position is equal to the target electrical signal quantization value, and focusing can be completed.

[0141] (2) If the actual quantized value of the electrical signal is equal to the target quantized value of the electrical signal, the position of the lens barrel is kept stationary, that is, there is no need to rotate the lens barrel.

[0142] That is, if the actual electrical signal quantization value is equal to the target electrical signal quantization value, it indicates that the electrical signal quantization value under the reflectivity corresponding to the current lens barrel position is equal to the target electrical signal quantization value. At this time, the lens is already in the ideal focusing position, that is, the target lens position mentioned above, so there is no need to adjust the electrical signal quantization value at the current moment, and there is no need to rotate the lens barrel.

[0143] (3) If the actual quantized value of the electric signal is greater than the target quantized value of the electric signal, the lens barrel is driven to rotate in a second direction, wherein the second direction is a direction in which the quantized value of the electric signal decreases.

[0144] It should be noted that the first direction and the second direction are relative directions, that is, the opposite direction of the first direction is the second direction, and the opposite direction of the second direction is the first direction.

[0145] That is, if the actual electrical signal quantization value is greater than the target electrical signal quantization value, it indicates that the electrical signal quantization value under the reflectivity corresponding to the current barrel position is greater than the target electrical signal quantization value. The current electrical signal quantization value needs to be reduced to reach the size of the target electrical signal quantization value in order to drive the lens to the ideal focusing position. At this time, the barrel is driven to rotate in the second direction until the electrical signal quantization value at the barrel position is equal to the target electrical signal quantization value, and focusing can be completed.

[0146] In some embodiments, when the outer wall of the lens barrel has a reflective film, in order to prevent the projection lens from being damaged by excessive rotation during the process of driving the lens barrel to rotate, the embodiment of the present application can set a corresponding protective area on the reflective film.

[0147] Based on this, when the lens barrel rotates along the target direction, if the quantized value of the electrical signal corresponding to the actual position of the lens reaches the quantized threshold, a protection instruction is generated; in response to the protection instruction, the lens barrel is driven to rotate in the opposite direction of the target direction.

[0148] The target direction includes the first direction or the second direction, and the quantization threshold is the quantization value of the electrical signal corresponding to the protection area of ​​the reflective film.

[0149] As an example, when the quantized value of the electrical signal is a voltage value, the quantization threshold can be specifically a voltage threshold. The voltage threshold can be flexibly set according to actual conditions. For example, if the voltage threshold is set to 0, when the actual voltage value corresponding to the actual position of the lens is 0, a protection instruction is immediately generated, and the lens barrel is driven to rotate in the opposite direction.

[0150] In some embodiments, in response to the protection instruction, the control device may also stop driving the lens barrel to rotate and wait for the user's next instruction. This embodiment of the present application does not limit this.

[0151] In a possible implementation, the length direction of the reflective film is distributed along the circumference of the outer wall of the lens barrel, and both ends of the reflective film include a protective area. That is, the reflective film has two protective areas.

[0152] As an example, as shown in Figure 10, the area 110 on the reflective film 11 is the protection area. Combined with Figure 9, when the reflective film rotates with the lens barrel, if point A falls on the protection area on the reflective film, the voltage value obtained by the photoelectric sensor after detection is the voltage threshold. At this time, when the control device determines that the current actual voltage value reaches the voltage threshold, it will immediately generate a protection instruction and stop the rotation of the lens barrel, or control the lens barrel to rotate in the opposite direction of the target direction.

[0153] In summary, in the embodiment of the present application, upon receiving a focus instruction, the control device can directly determine the focus adjustment parameter of the lens based on the first distance between the projection lens and the projection medium. Since the focus adjustment parameter indicates the position of the lens when the image projected by the laser projection device is clearest, that is, the embodiment of the present application can directly determine the position of the lens when the image projected by the laser projection device is clearest based on the first distance, and then directly move the lens to that position to complete the focus. Compared to the method of repeatedly taking pictures and analyzing the clarity in the related art, the embodiment of the present application greatly reduces the time consumed in the focusing process and improves focusing efficiency.

[0154] FIG11 is a schematic diagram of the structure of a control device provided in an embodiment of the present application. As previously described, a laser projection device includes a projection lens and a control device. The projection lens includes a lens barrel and a lens located within the lens barrel. The control device can be implemented as a component of the laser projection device using software, hardware, or a combination of both. For example, the control device can be included in the mainboard of the laser projection device. Referring to FIG11 , the control device includes:

[0155] The distance acquisition module 1101 is configured to acquire a first distance in response to a focus instruction, wherein the first distance is the distance between the projection lens and the projection medium at a current moment;

[0156] A parameter determination module 1102 is configured to determine a focus adjustment parameter of the lens based on the first distance; wherein the focus adjustment parameter indicates a position of the lens when the image projected by the laser projection device is clearest;

[0157] The position adjustment module 1103 is configured to drive the lens barrel to rotate based on the focus adjustment parameter, so as to move the lens to the position indicated by the focus adjustment parameter.

[0158] In one possible implementation, the focus adjustment parameter includes a target lens position; and the position adjustment module 1103 includes:

[0159] A position acquisition unit is used to acquire the actual position of the lens at the current moment to obtain the actual lens position;

[0160] The first adjustment unit is used to drive the lens barrel to rotate based on the target lens position and the actual lens position, so as to drive the lens to move from the actual lens position to the target lens position.

[0161] In a possible implementation, the first adjustment unit is further configured to:

[0162] Based on the first distance, the target lens position is obtained from a first mapping relationship; wherein the first mapping relationship is a mapping relationship between the projection distance and the lens position, and the projection distance refers to the distance between the projection lens and the projection medium.

[0163] In one possible implementation, the outer wall of the lens barrel has a reflective film, and different reflective positions on the reflective film have different reflectivities, and the focus adjustment parameter includes the target reflectivity; the position adjustment module 1103 includes:

[0164] A reflectivity acquisition unit, used to acquire the actual reflectivity of the reflective film at the current moment;

[0165] The second adjustment unit is used to drive the lens barrel to rotate based on the target reflectivity and the actual reflectivity, so as to adjust the reflectivity of the reflective film to the target reflectivity.

[0166] In one possible implementation, the outer wall of the lens barrel has a reflective film, and different reflective positions on the reflective film have different reflectivities, and the focus adjustment parameter includes the target reflectivity; the position adjustment module 1103 includes:

[0167] A first quantization value acquisition unit is used to acquire a target electrical signal quantization value corresponding to a target reflectivity; wherein different reflectivities of the reflective film correspond to different electrical signal quantization values;

[0168] The first quantized value obtaining unit is further configured to obtain the quantized value of the electrical signal corresponding to the actual position of the lens at the current moment, thereby obtaining the actual quantized value of the electrical signal;

[0169] The third adjustment unit is used to drive the lens barrel to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value, so as to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target quantization value.

[0170] In a possible implementation, the second adjustment unit is specifically configured to:

[0171] Based on the first distance, the target reflectivity is obtained from a second mapping relationship; wherein the second mapping relationship is a mapping relationship between projection distance and reflectivity, and the projection distance refers to the distance between the projection lens and the projection medium.

[0172] In one possible implementation, the outer wall of the lens barrel has a reflective film, and different reflective positions on the reflective film have different reflectivities. Different reflectivities of the reflective film correspond to different quantized values ​​of the electrical signal. The focus adjustment parameter includes the quantized value of the target electrical signal. The position adjustment module 1103 includes:

[0173] The second quantization value obtaining unit is used to obtain the quantization value of the electric signal corresponding to the actual position of the lens at the current moment, and obtain the actual quantization value of the electric signal;

[0174] The fourth adjustment unit is used to drive the lens barrel to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value, so as to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target electrical signal quantization value.

[0175] In a possible implementation, the fourth adjustment unit is specifically configured to:

[0176] Based on the first distance, a target electrical signal quantization value is obtained from a third mapping relationship; wherein the third mapping relationship is a mapping relationship between the projection distance and the electrical signal quantization value, and the projection distance refers to the distance between the projection lens and the projection medium.

[0177] In a possible implementation, the projection lens further includes a photoelectric sensor; the photoelectric sensor is configured to:

[0178] In response to a control instruction sent by the control device, emitting a first light toward the lens barrel;

[0179] receiving a second light beam reflected by the first light beam through the reflective film;

[0180] Based on the second light, an actual quantized value of the electric signal is determined, and the actual quantized value of the electric signal is sent to the control device.

[0181] In a possible implementation, the position adjustment module 1103 is further configured to:

[0182] If the actual quantized value of the electrical signal is less than the target quantized value of the electrical signal, the lens barrel is driven to rotate along a first direction, where the first direction is a direction in which the quantized value of the electrical signal increases;

[0183] If the actual electrical signal quantization value is equal to the target electrical signal quantization value, the position of the lens barrel is kept unchanged;

[0184] When the actual quantized value of the electric signal is greater than the target quantized value of the electric signal, the lens barrel is driven to rotate along a second direction, where the second direction is a direction in which the quantized value of the electric signal decreases.

[0185] In a possible implementation, the reflective film includes a protective area; and the position adjustment module 1103 is further configured to:

[0186] During the process of the lens barrel rotating in the target direction, if the quantized value of the electrical signal corresponding to the actual position of the lens reaches a quantized threshold, a protection instruction is generated; wherein the quantized threshold is the quantized value of the electrical signal corresponding to the protection area of ​​the reflective film;

[0187] In response to the protection instruction, the lens barrel is driven to rotate in a direction opposite to the target direction.

[0188] In a possible implementation, the length direction of the reflective film is distributed along the circumference of the outer wall of the lens barrel, and both ends of the reflective film include protection areas, and the target direction includes the first direction or the second direction.

[0189] In a possible implementation, the quantized value of the electrical signal is a voltage value or a current value.

[0190] In a possible implementation, the projection lens further includes a DC motor, and the DC motor is connected to the lens barrel; the DC motor is configured as follows:

[0191] In response to the control instruction sent by the control device, the lens barrel is driven to rotate to drive the lens to move.

[0192] In a possible implementation, the control device further includes:

[0193] The instruction acquisition module is used to generate a focus instruction when a change in the position of the laser projection device is detected; or to receive a focus instruction issued by a user.

[0194] In summary, in the embodiment of the present application, upon receiving a focus instruction, the control device can directly determine the focus adjustment parameters of the lens based on the first distance between the projection lens and the projection medium. Since the focus adjustment parameters indicate the position of the lens when the image projected by the laser projection device is clearest, in other words, the embodiment of the present application can directly determine the position of the lens when the image projected by the laser projection device is clearest based on the first distance, and then move the lens to that position to complete the focus. Compared to the method of repeatedly taking pictures and analyzing the clarity in the related art, the embodiment of the present application greatly reduces the time consumed in the focusing process and improves focusing efficiency.

[0195] It should be noted that the control device for the laser projection device provided in the above embodiment only uses the division of the above functional modules as an example to illustrate when controlling the laser projection device for focusing. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the control device for the laser projection device provided in the above embodiment and the focusing method embodiment shown in Figure 8 above are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0196] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the processor implements the focusing method described in the embodiment of the present application. The specific implementation method and technical effect are similar and will not be repeated here.

[0197] The computer-readable storage medium may include a USB flash drive, a mobile hard drive, a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. The computer-readable storage medium may also be a non-volatile storage medium, in other words, a non-transient storage medium.

[0198] It should be understood that all or part of the steps for implementing the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the steps may be implemented in the form of a computer program product. The computer program product may include one or more computer instructions, which may be stored in the computer-readable storage medium described above.

[0199] That is, the embodiment of the present application also provides a computer program product. When the computer program product runs on a computer, the computer executes the focusing method described in the embodiment of the present application. The specific implementation method and technical effect are similar and will not be repeated here.

[0200] It should be understood that the "at least one" mentioned herein refers to one or more, and "a plurality of" refers to two or more. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0201] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.) and signals involved in the embodiments of this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with the relevant laws, regulations and standards of relevant countries and regions.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, a person skilled in the art can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0203] The above description is an embodiment provided for this application and is not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A laser projection device, characterized in that: The laser projection device comprises: a projection lens and a control device, wherein the projection lens comprises a lens barrel and a lens located in the lens barrel; and the control device is configured to: In response to the focus instruction, a first distance is acquired; wherein the first distance is the distance between the projection lens and the projection medium at the current moment; Based on the first distance, determining a focus adjustment parameter of the lens; wherein the focus adjustment parameter indicates the position of the lens when the image projected by the laser projection device is clearest; Based on the focus adjustment parameter, the lens barrel is driven to rotate so as to drive the lens to move to a position indicated by the focus adjustment parameter.

2. The laser projection device according to claim 1, characterized in that: The focus adjustment parameters include the target lens position; the control device is specifically configured as follows: Obtaining the actual position of the lens at the current moment to obtain the actual lens position; The lens barrel is driven to rotate based on the target lens position and the actual lens position, so as to drive the lens to move from the actual lens position to the target lens position.

3. The laser projection device according to claim 2, characterized in that: The control device is specifically configured as follows: Based on the first distance, the target lens position is acquired from a first mapping relationship; wherein the first mapping relationship is a mapping relationship between a projection distance and a lens position, and the projection distance refers to a distance between the projection lens and the projection medium.

4. The laser projection device according to claim 1, characterized in that: The outer wall of the lens barrel has a reflective film, and the reflective rates of different reflective positions on the reflective film are different, and the focus adjustment parameter includes a target reflective rate; the control device is specifically configured as follows: Obtaining the actual reflectivity of the reflective film at the current moment; The lens barrel is driven to rotate based on the target reflectivity and the actual reflectivity to adjust the reflectivity of the reflective film to the target reflectivity.

5. The laser projection device according to claim 1, characterized in that: The outer wall of the lens barrel has a reflective film, and the reflective rates of different reflective positions on the reflective film are different, and the focus adjustment parameter includes a target reflective rate; the control device is specifically configured as follows: Obtaining a target electrical signal quantization value corresponding to the target reflectivity; wherein different reflectivities of the reflective film correspond to different electrical signal quantization values; Obtain the quantized value of the electrical signal corresponding to the actual position of the lens at the current moment, and obtain the actual electrical Signal quantization value; The lens barrel is driven to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value, so as to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target quantization value.

6. The laser projection device according to claim 4 or 5, characterized in that: The control device is specifically configured as follows: Based on the first distance, the target reflectivity is acquired from a second mapping relationship; wherein the second mapping relationship is a mapping relationship between projection distance and reflectivity, and the projection distance refers to the distance between the projection lens and the projection medium.

7. The laser projection device according to claim 1, characterized in that: The outer wall of the lens barrel has a reflective film, and the reflective film has different reflective rates at different reflective positions. Different reflective rates of the reflective film correspond to different quantized values ​​of the electrical signal. The focus adjustment parameter includes the quantized value of the target electrical signal. The control device is specifically configured as follows: Obtaining the quantized value of the electrical signal corresponding to the actual position of the lens at the current moment, to obtain the actual quantized value of the electrical signal; The lens barrel is driven to rotate based on the target electrical signal quantization value and the actual electrical signal quantization value, so as to adjust the electrical signal quantization value corresponding to the actual position of the lens to the target electrical signal quantization value.

8. The laser projection device according to claim 7, characterized in that: The control device is specifically configured as follows: Based on the first distance, the target electrical signal quantization value is obtained from a third mapping relationship; wherein the third mapping relationship is a mapping relationship between a projection distance and an electrical signal quantization value, and the projection distance refers to a distance between the projection lens and the projection medium.

9. The laser projection device according to claim 5 or 7, characterized in that: The projection lens further includes a photoelectric sensor; the photoelectric sensor is configured as follows: emitting a first light beam toward the lens barrel; receiving a second light beam reflected by the first light beam through the reflective film; Based on the second light, the actual quantized value of the electrical signal is determined.

10. The laser projection device according to claim 5 or 7, characterized in that: The control device is specifically configured as follows: If the actual quantized value of the electrical signal is less than the target quantized value of the electrical signal, driving the lens barrel to rotate along a first direction, where the first direction is a direction in which the quantized value of the electrical signal increases; If the actual quantized value of the electrical signal is equal to the target quantized value of the electrical signal, the position of the lens barrel is kept unchanged; If the actual electrical signal quantization value is greater than the target electrical signal quantization value, the lens barrel is driven to move along The electric signal rotates in a second direction, where the second direction is a direction in which the quantized value of the electric signal decreases.

11. The laser projection device according to claim 10, characterized in that: The reflective film includes a protective area; the control device is further configured to: During the rotation of the lens barrel along the target direction, if the quantized value of the electrical signal corresponding to the actual position of the lens reaches a quantized threshold, a protection instruction is generated; wherein the quantized threshold is the quantized value of the electrical signal corresponding to the protection area of ​​the reflective film; In response to the protection instruction, the lens barrel is driven to rotate in a direction opposite to the target direction.

12. The laser projection device according to claim 11, characterized in that: The length direction of the reflective film is distributed along the circumferential direction of the outer wall of the lens barrel, and both ends of the reflective film include the protection area, and the target direction includes the first direction or the second direction.

13. The laser projection device according to any one of claims 5, 7 to 11, characterized in that: The quantized value of the electrical signal is a voltage value or a current value.

14. The laser projection device according to claim 1, characterized in that: The projection lens further includes a DC motor, and the DC motor is connected to the lens barrel; the DC motor is configured as follows: The lens barrel is driven to rotate to drive the lens to move.

15. The laser projection device according to claim 1, characterized in that: The control device is further configured to: When a change in the position of the laser projection device is detected, generating the focus instruction; Alternatively, the focus instruction sent by the user is received.

16. A focusing method, characterized in that: Applied to a laser projection device, the laser projection device comprises: a projection lens and a control device, the projection lens comprises a lens barrel and a lens located in the lens barrel; the method comprises: In response to the focus instruction, a first distance is acquired; wherein the first distance is the distance between the projection lens and the projection medium at the current moment; Based on the first distance, determining a focus adjustment parameter of the lens; wherein the focus adjustment parameter indicates the position of the lens when the image projected by the laser projection device is clearest; Based on the focus adjustment parameter, the lens barrel is driven to rotate so as to drive the lens to move to a position indicated by the focus adjustment parameter.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to claim 16 is implemented.

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