Image following method when screen of projection device is raised or lowered and projection device

Abstract

The present application provides an image following method and a projection device when the screen of a projection device is raised or lowered, and the moving height of the screen during movement is monitored by a monitoring component. The screen is a screen that can be rolled up and raised. After receiving the moving height of the screen, the controller calculates the projection height according to the moving height using a preset rule. The preset rule specifies the mapping relationship between the moving height and the projection height. Finally, according to the projection height, the projection component is controlled to project an image of corresponding height onto the screen. The embodiment of the present application can calculate the height of the image to be projected according to the moving height of the screen during the movement of the screen, so as to achieve the effect of the image rising and falling synchronously with the screen, thereby improving the user viewing experience.

Description

Technical Field

[0001] The present application relates to the technical field of projection equipment, and in particular to an image following method when a screen of a projection equipment is raised or lowered, and a projection equipment. Background Art

[0002] Television technology has gone through three technological iterations: black and white television, color television, and digital television represented by LCD TV, PDP, OLED, etc. Currently, the fourth generation of television display technology, laser TV technology, has emerged, which is a combination of laser projection equipment and screens. Currently, laser TVs mainly include laser projection equipment and screens. Due to the large screen size, a rollable screen has emerged to reduce the product size.

[0003] At present, the development of laser TV technology has shown a variety of new forms, and the integration of TV and liftable screen is one of them. This new form of laser TV cannot ensure that the projected image will rise and fall with the screen when the TV is turned on and off, resulting in a poor viewing experience for users. Therefore, for this new form of laser TV, a mechanism is urgently needed to ensure that the image can rise and fall synchronously during the screen lifting process. Summary of the invention

[0004] The present application provides a method for image following when the screen of a projection device is raised or lowered and a projection device, which are used to solve the problem that a new form of laser TV cannot ensure that the projected image follows the screen when the TV is turned on or off, resulting in a poor viewing experience for users.

[0005] In a first aspect, this embodiment provides a projection device, including:

[0006] A projection assembly, configured to project an image onto a screen, wherein the screen is a liftable screen;

[0007] A monitoring component is configured to monitor the moving height of the screen during the movement of the screen and feed back the moving height to the controller;

[0008] The controller is configured as:

[0009] Calculating a projection height according to the moving height using a preset rule, wherein the preset rule specifies a mapping relationship between the moving height and the projection height;

[0010] According to the projection height, the projection component is controlled to project an image of corresponding height onto the screen.

[0011] In a second aspect, this embodiment provides an image following method when a screen of a projection device is raised or lowered, the projection device comprising:

[0012] The projection component is configured to project an image onto a screen, and the screen is a liftable screen; the monitoring component is configured to monitor the moving height of the screen during the movement of the screen, and feed back the moving height to a controller, and the method includes:

[0013] Calculating a projection height according to the moving height using a preset rule, wherein the preset rule specifies a mapping relationship between the moving height and the projection height;

[0014] According to the projection height, the projection component is controlled to project an image of corresponding height onto the screen.

[0015] The image following method and projection device provided in the embodiment of the present application monitor the moving height of the screen during the movement of the screen through a monitoring component. The screen is a screen that can be rolled up and raised. After receiving the moving height of the screen, the controller calculates the projection height according to the moving height using a preset rule. The preset rule specifies the mapping relationship between the moving height and the projection height. Finally, according to the projection height, the projection component is controlled to project an image of the corresponding height onto the screen. The embodiment of the present application can calculate the height of the image to be projected according to the moving height of the screen during the movement of the screen, so as to achieve the effect of the image rising and falling synchronously with the screen, thereby improving the user viewing experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0017] Figure 1 Schematic diagram of an operation scenario between a laser TV and a control device according to an embodiment is exemplarily shown in FIG.

[0018] Figure 2 exemplarily shows a configuration block diagram of a control device 100 according to an exemplary embodiment;

[0019] Figure 3 Schematic diagram of the hardware structure of the laser TV 200 according to an exemplary embodiment is shown in FIG.

[0020] Figure 4 exemplarily shows a hardware structure diagram of another laser TV 200 according to an exemplary embodiment;

[0021] Figure 5 The structure diagram of the laser projection device provided in the embodiment of the present application is exemplarily shown in FIG.

[0022] Figure 6 The schematic diagram of the state switching mechanism framework provided by the embodiment of the present application is exemplarily shown in FIG.

[0023] Figure 7 Schematic diagram of screen rising curve provided by an embodiment of the present application is exemplarily shown in FIG.

[0024] Figure 8 exemplarily shows a schematic diagram of a screen image captured by the image capture device provided in an embodiment of the present application;

[0025] Fig. 9 A schematic diagram of a screen image captured by another image capture device provided in an embodiment of the present application is exemplarily shown in FIG.

[0026] Fig.10 A signaling diagram of a state switching implementation method provided by an embodiment of the present application is exemplarily shown in FIG.

[0027] Fig.11 A signaling diagram of another state switching implementation method provided in an embodiment of the present application is exemplarily shown in FIG.

[0028] Fig.12 A signaling diagram of another state switching implementation method provided in an embodiment of the present application is exemplarily shown in FIG.

[0029] Fig.13 exemplarily shows a signaling schematic diagram of a method for switching a screen lifting state of a projection device according to an embodiment of the present application;

[0030] Fig.14 Schematic diagram of projection when the screen of the projection device according to the embodiment of the present application is in an ascending state is shown in the figure;

[0031] Fig.15 exemplarily shows a projection schematic diagram when the screen of the projection device according to an embodiment of the present application is at the highest point;

[0032] Fig.16 exemplarily shows a projection schematic diagram of a projection device in an embodiment of the present application when the screen output is in a descending state;

[0033] Fig.17 A signaling diagram of an image following method when the screen of a projection device is raised or lowered provided by an embodiment of the present invention.

[0034] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0035] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0036] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0037] The terms "including" and "having" and any variations thereof are intended to cover but not exclude inclusion, for example, a product or device comprising a series of components is not necessarily limited to those components explicitly listed, but may include other components not explicitly listed or inherent to these products or devices. The term "module" or "component" as used in this application refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic or combination of hardware and / or software code that can perform the functions associated with the element.

[0038] The term "remote control" used in the embodiments of the present application refers to a component of an electronic device (such as the display device disclosed in the present application), which can usually wirelessly control the electronic device within a relatively short distance. The component can generally be connected to the electronic device using infrared and / or radio frequency (RF) signals and / or Bluetooth, and may also include functional modules such as WiFi, wireless USB, Bluetooth, motion sensors, etc. For example: a handheld touch remote control replaces most of the physical built-in hardware in a general remote control device with a user interface in a touch screen.

[0039] Figure 1 FIG. 2 is a schematic diagram showing an operation scenario between a laser TV and a control device according to an embodiment. Figure 1 As shown, the user can operate the laser TV 200 through the control device 100.

[0040] The control device 100 may be a remote controller 100A, which may communicate with the laser TV 200 via infrared protocol communication, Bluetooth protocol communication, ZigBee protocol communication or other short-distance communication methods, and is used to control the laser TV 200 wirelessly or in other wired ways. The user may input user commands through buttons on the remote controller 100A, voice input, control panel input, etc. to control the laser TV 200. For example, the user may input corresponding control commands through the screen 201 up / down keys, volume up / down keys, channel control keys, up / down / left / right movement keys, voice input keys, menu keys, power on / off keys, etc. on the remote controller 100A to realize the function of controlling the laser TV 200.

[0041] The control device 100 may also be a smart device, such as a mobile terminal 100B, a tablet computer, a computer, a laptop computer, etc., which can communicate with the laser TV 200 through a local area network (LAN), a wide area network (WAN), a wireless local area network (WLAN) or other networks, and control the laser TV 200 through an application corresponding to the laser TV 200. For example, the laser TV 200 is controlled using an application running on a smart device. The application can provide the user with various controls through an intuitive user interface (UI) on a screen 201 associated with the smart device.

[0042] For example, both the mobile terminal 100B and the laser TV 200 can be installed with software applications, so that the connection and communication between the two can be realized through the network communication protocol, thereby achieving the purpose of one-to-one control operation and data communication. For example, the mobile terminal 100B can establish a control command protocol with the laser TV 200, synchronize the remote control keyboard to the mobile terminal 100B, and realize the function of controlling the laser TV 200 by controlling the user interface on the mobile terminal 100B; the audio and video content displayed on the mobile terminal 100B can also be transmitted to the laser TV 200 to realize the synchronous display function.

[0043] like Figure 1 As shown, the laser TV 200 can also communicate data with the server 300 through various communication methods. In various embodiments of the present application, the laser TV 200 can be connected to the server 300 by wired communication or wireless communication through a local area network, a wireless local area network or other network. The server 300 can provide various content and interactions to the laser TV 200.

[0044] For example, the laser TV 200 receives software program updates or accesses a remotely stored digital media library by sending and receiving information and interacting with an electronic program guide (EPG). The server 300 can be one group or multiple groups, and can be one or more types of servers. Other network service content such as video on demand and advertising services are provided through the server 300.

[0045] The laser TV 200 includes a screen 201 and a laser projection device 202. The laser projection device 202 obtains the content to be displayed, and projects the content to be displayed to the screen 201 by optical projection imaging, so that the screen 201 displays the content to be displayed. The specific type, size, and resolution of the laser TV are not limited. It can be understood by those skilled in the art that the laser TV 200 can make some changes in performance and configuration as needed.

[0046] In addition to providing the broadcast receiving TV function, the laser TV 200 may also provide an intelligent network TV function that provides computer support functions. Examples include network TV, smart TV, Internet Protocol TV (IPTV), etc. In some embodiments, the laser TV may not have the broadcast receiving TV function.

[0047] In other examples, more functions may be added or the above functions may be reduced. This application does not specifically limit the functions of the laser TV.

[0048] Figure 2 FIG. 2 exemplarily shows a block diagram of a configuration of a control device 100 according to an exemplary embodiment. Figure 2 As shown, the control device 100 includes a controller 110 , a communicator 130 , a user input / output interface 140 , a memory 190 , and a power supply 180 .

[0049] The control device 100 is configured to control the laser TV 200, receive the user's input operation instructions, and convert the operation instructions into instructions that the laser TV 200 can recognize and respond to, playing the role of an interactive intermediary between the user and the laser TV 200. For example: the user operates the channel plus and minus keys on the control device 100, and the laser TV 200 responds to the channel plus and minus operations. For another example: the user operates the screen 201 up and down keys on the control device 100, and the laser TV 200 responds to control the screen 201 to rise or fall. It should be noted that the "rise" or "fall" mentioned in this application is relative to the installation position of the screen 201. It can be understood that based on the different installation positions of the screen 201, the direction of "rise" or "fall" is different. For example, for the screen 201 installed on the ceiling, its "rise" and "fall" refer to the change of the screen 201 in the height direction, while for the screen 201 installed on the vertical side wall, the direction of "rise" and "fall" mentioned here is the change in the horizontal direction.

[0050] In some embodiments, the control device 100 may be a smart device. For example, the control device 100 may be installed with various applications for controlling the laser TV 200 according to user needs.

[0051] In some embodiments, Figure 1 As shown, the mobile terminal 100 or other smart electronic device can play a similar function to the control device 100 after installing the application for controlling the laser TV 200. For example, the user can install the application to realize the function of the physical button of the control device 100 through various function keys or virtual buttons of the graphical user interface provided on the mobile terminal 100B or other smart electronic device.

[0052] The controller 110 includes a processor, RAM and ROM, a communication interface and a communication bus. The controller 110 is used to control the operation and operation of the control device 100, as well as the communication and cooperation between the internal components and the external and internal data processing functions.

[0053] Under the control of the controller 110, the communicator 130 realizes the communication of control signals and data signals with the laser TV 200. For example, the received user input signal is sent to the laser TV 200. The communicator 130 may include at least one of a WIFI module, a Bluetooth module, an NFC module, and other communication modules.

[0054] The user input / output interface 140 includes at least one of a microphone, a touch panel, a sensor, a button, a camera, etc. For example, the user can input a user command through voice, touch, gesture, pressing, etc. The input interface converts the received analog signal into a digital signal, and the digital signal into a corresponding command signal, and sends it to the laser TV 200.

[0055] The output interface includes an interface for sending received user commands to the laser TV 200. In some embodiments, it can be an infrared interface or a radio frequency interface. For example, in the case of an infrared signal interface, the user input command needs to be converted into an infrared control signal according to the infrared control protocol, and then sent to the laser TV 200 via the infrared sending module. Another example: in the case of a radio frequency signal interface, the user input command needs to be converted into a digital signal, and then modulated according to the radio frequency control signal modulation protocol, and then sent to the laser TV 200 by the radio frequency sending terminal.

[0056] In some embodiments, the control device 100 includes at least one of a communicator 130 and an output interface. The control device 100 is configured with a communicator 130, such as a WIFI, Bluetooth, NFC or other module, which can encode the user input command through the WIFI protocol, Bluetooth protocol, or NFC protocol and send it to the laser TV 200.

[0057] Figure 3 FIG. 2 is a schematic diagram showing a hardware structure of a laser TV 200 according to an exemplary embodiment. For ease of explanation, Figure 3 The laser TV 200 is illustrated by taking the laser projection device 202 and the screen 201 as being separately arranged.

[0058] Figure 3 As shown, the laser TV 200 includes: a laser projection device 202 and a screen 201. The laser projection device 202 is used to obtain the video to be played. Specifically, the laser projection device 202 can parse the video signal to be played into an image signal and project it onto the screen 201 to form an image. The screen 201 is used to present the picture to the user.

[0059] In this application, in addition to the separate arrangement of the laser projection device 202 and the screen 201, in order to reduce the occupied space, in another arrangement, the laser projection device 202 and the screen 201 are made into one piece. As an example, Figure 4 As shown, the laser TV 200 of this solution integrates the laser projection device 202 and the screen 201 in the TV cabinet, and a sliding cover and a flip cover are provided on the TV cabinet, which are respectively used to shield the laser projection device 202 and the screen 201 when the laser TV 200 is not working. When the laser TV 200 is in working state, the sliding cover and the flip cover are opened, and the screen 201 is unfolded or retracted by the operation of the screen 201 transmission assembly.

[0060] In the embodiment where the laser projection device 202 is integrated with the screen 201, when the laser projection device 202 is turned on and off, it is impossible to ensure that the screen 201 rises and falls synchronously. In order to solve this problem, an embodiment of the present invention provides a laser projection device 202, which can ensure that when the laser projection device 202 is turned on and off, the screen 201 rises and falls synchronously.

[0061] Figure 5 The structure diagram of the laser projection device 202 provided in the first embodiment of the present application is exemplarily shown in FIG. Figure 5 As shown, the laser projection device 202 includes: a controller 11 provided with a communication terminal, a projection display component 12, a power board 13 provided with a power supply terminal, and an audio output component 14; wherein the power supply terminal is used to receive an external power signal, and the power board 13 is connected to the controller 11, the projection display component 12 and the audio output component 14; the controller 11 is connected to the projection display component 12 and the audio output component 14; the communication terminal is used for an external screen 201.

[0062] Take the working scenario of the laser TV as an example: when the power supply terminal is connected to an external power signal, the power board 13 converts the external power signal into a power supply signal, and under the control of the controller 11, supplies power to the projection display component 12 and the audio output component 14; when the communication terminal is connected to the screen 201, the controller 11 parses the image signal and the audio signal according to the video signal to be played, and instructs the projection display component 12 to project and display the corresponding image to the projection area, and controls the audio output component 14 to output the corresponding audio; wherein the controller 11 also obtains the position information of the screen 201 in real time, and controls the projection area of ​​the projection display component 12 to be consistent with the position of the screen 201.

[0063] Among them, the controller 11 is mainly responsible for controlling the power board 13, the projection display component 12, and the related components in the screen 201. For example, the controller 11 controls the power board 13 to supply power to which component at which time, so as to optimize the power supply control strategy, realize effective control and save power. For another example, the controller 11 controls the projection display component 12 to project an image at which time and to turn off the backlight at which time. For another example, the controller 11 controls the screen 201 to start raising and lowering the screen 201 at which time, and adjusts the projection area of ​​the projection display component 12 according to the rising height, rising time, descending height, and descending time fed back by the screen 201, so as to realize the synchronization of the projection area and the screen 201.

[0064] Specifically, the functions supported by the controller 11 include but are not limited to audio and video encoding and decoding functions, video signal processing functions, and signal output functions (for example, supporting the output of VB1 signals or LVDS signals). In order to facilitate communication with other components, the controller 11 can also support some data transmission interfaces and their corresponding software communication protocols, such as RS2332 (the corresponding communication protocol adopts serial communication mode), RJ45 (the corresponding communication protocol adopts Modbus communication mode), USB (the corresponding communication protocol adopts USB communication mode), High Definition Multimedia Interface (HDMI for short), etc. In the figure, the communication interaction mode of I2C and general-purpose input / output (GPIO for short) is used as an example between the controller 11 and the projection display component. In actual applications, the controller 11 can be integrated on the mainboard chip of the laser projection device 202, or a multimedia function chip with the above functions can be specially set to achieve it.

[0065] In this embodiment, the controller 11 can establish a connection with the screen 201 through a communication terminal. The connection here includes but is not limited to: wired communication connection, wireless communication connection, etc. Among them, in the wired connection mode, the communication terminal is a hardware socket, and accordingly, the screen 201 is provided with a corresponding hardware socket, and these two hardware sockets can establish the wired communication connection by connecting a data line. The main communication commands include but are not limited to: power on, power off, rise, pause, fall, accelerate, decelerate, abnormal, zero point state, etc.

[0066] In this embodiment, the laser projection device 202 also includes a monitoring component 15, which is mainly responsible for monitoring the current state of the screen 201. In this embodiment, the state of the screen 201 monitored by the monitoring component does not refer to the position state of the screen 201, but the state preset in the state switching mechanism. The state here is the state information stored in the screen 201 after the last state switching. For example, after the last state switching, the state is the top state, and the state information stored in the screen 201 is the top state information. An identifier can be set for each state, for example, the identifier of the top state is T. Before the next switching, the monitoring component reads the state identifier from the storage device of the screen 201, and determines the current state of the screen 201 by the state identifier. And the state switching mechanism is a preset mechanism. After the controller 11 receives the current state of the screen 201 monitored by the monitoring component, it switches the current state of the screen 201 according to the state switching mechanism. Further, the controller 11 controls the screen 201 to perform a corresponding operation according to the current state of the screen 201 after switching. The operation corresponding to the state performed by the screen is a moving operation, such as rising, falling, and keeping still.

[0067] For example, if the current state of the screen 201 is the first state, and in the state switching mechanism, the next state of the first state is the second state, then according to the state switching mechanism, the screen 201 is controlled to switch from the first state to the second state. At the same time, the screen 201 is controlled to perform the corresponding operation of the second state. That is to say, in this embodiment, the sequence relationship of multiple states of the screen 201 is preset in advance, and according to the preset sequence relationship, the current state of the screen 201 is switched, and the screen 201 is controlled to perform the corresponding operation. In this way, the lifting and lowering of the screen 201 is directly controlled by the state switching, so as to ensure that when the laser projection device 202 is turned on and off, the screen 201 follows the lifting and lowering synchronously, and finally improves the user's viewing experience.

[0068] The screen involved in this embodiment can carry the media resources projected by the projection component and display the media resources to the user. In some feasible embodiments, the screen can be a diffuse reflection screen or a regression screen. It is worth noting that this embodiment only shows two types of screens by way of example. In actual application, the screen can be but is not limited to the above two displays. Any screen that can be used to carry the media resources projected by the projection component and can complete the rolling or extending action can be applied to the solution shown in this embodiment.

[0069] The scheme of the embodiment of the present invention will be described in detail below in conjunction with specific embodiments. Figure 6 exemplarily shows a schematic diagram of the screen 201 state switching mechanism framework provided in an embodiment of the present application. Figure 6 The states shown in the figure can be used as the first state or the second state. The second state is always the next state of the first state. For example, when the bottom state is the first state, the zero state is the second state, and the bottom state is switched to the zero state when the state is switched. When the zero state is the first state, the ready-to-rise state is the second state. When the state is switched, the zero state is switched to the ready-to-rise state. Figure 6 The arrows shown are used to switch the sequence.

[0070] It should be noted that there is a two-way arrow between the rising state and the obstacle detected state. That is to say, when the rising state is the first state, if an obstacle is detected blocking the movement of the screen, the obstacle detected state is the second state. If the obstacle is detected to be removed, the obstacle detected state is the first state, and the rising state is the second state. If the rising state is the first state, and no obstacle is detected blocking the movement of the screen, the top state is the second state. Similarly, when the descending state is the first state, if an obstacle is detected blocking the movement of the screen, the obstacle detected state is the second state. If the obstacle is detected to be removed, the obstacle detected state is the first state, and the descending state is the second state. If the descending state is the first state, and no obstacle is detected blocking the movement of the screen, the bottom state is the second state.

[0071] like Figure 6 As shown, in the state switching mechanism, if the current state of the screen 201 is the bottom state, the laser projection device 202 is in the off state. The corresponding position of the bottom state is the lowest position that the screen 201 can move, that is, when the current state of the screen 201 is the bottom state, the screen 201 is at the lowest point.

[0072] like Figure 7 As shown in the screen rise curve, the screen rise process is divided into the reset stage, acceleration stage, uniform speed stage and deceleration stage. The reset stage is the process of the screen rising from the absolute zero point of the screen to the reference zero point. The rising speed of the screen in the reset stage is the acceleration process. The acceleration stage is the process of the screen starting to rise from the reference zero point, and the rising speed increases from a lower value to a higher value. When the rising speed of the screen increases to the preset uniform speed, it enters the uniform speed stage. The screen continues to rise at the preset uniform speed and maintains a uniform rise. When the height reaches the second highest point (the starting position of the deceleration stage), the screen rising speed begins to decrease, and the screen rising process enters the deceleration stage until the screen rises to the highest point.

[0073] based on Figure 7 As shown in the screen rising curve diagram, when the state of the screen is the bottom state, the screen is located at the lowest point position of the screen that can be moved (i.e. Figure 7 When the screen is in the zero point state, the screen is located at the preset reference position of the screen (i.e. Figure 7 ); when the state of the screen is the ready-to-rise state, the screen is located at the preset reference position of the screen; when the state of the screen is the rising state, the moving direction of the screen is from the lowest point to the highest point; when the state of the screen is the top state, the screen is located at the highest point position of the movable screen (i.e. Figure 7when the state of the screen is a state of preparing to descend, the screen is located at the lowest point where the screen can move; when the state of the screen is a descending state, the moving direction of the screen is from the highest point to the lowest point; when the state of the screen is a state of detecting an obstacle, the screen pauses the ascending action or pauses the descending state.

[0074] In this embodiment, only the normal power on and off of the laser projection device 202 is considered, that is, when the laser projection device 202 is turned off, the screen 201 is always at the lowest point, and the abnormal power on and off situation (for example, the screen 201 has not yet dropped to the lowest point, and the laser projection device 202 is turned off) is not considered. That is, when the screen is at the bottom state, the screen is at the absolute zero point position, and when the screen is at the zero point state, the screen is at the reference zero point position.

[0075] While the current state of the screen 201 is the bottom state, a power-on command input by the user is received. According to the state sequence relationship in the state switching mechanism, the next state of the bottom state is the zero state, indicating that the bottom state is the first state and the zero state is the second state, then the control screen 201 is switched from the bottom state to the zero state. At the same time, the control screen 201 moves from the corresponding position of the bottom state to the corresponding position of the zero state. Among them, the corresponding position of the zero state is a preset reference position. In other words, while the control screen 201 switches from the bottom state to the zero state, the control screen 201 moves from the lowest point to the reference point. In this way, it can be ensured that when the laser projection device 202 is turned on, the screen 201 can be ensured to rise synchronously.

[0076] In some embodiments, after the screen 201 switches from the bottom state to the zero state, according to Figure 6 The state switching mechanism of the zero state is the ready-to-rise state, indicating that the zero state is the first state, and the ready-to-rise state is the second state. The control screen 201 switches from the zero state to the ready-to-rise state, and generates a start rising instruction. It should be noted that after the rising instruction is generated, the rising instruction is temporarily stored in the storage element, and the screen 201 is not controlled to make corresponding actions according to the rising instruction. In other words, when the screen 201 is in the ready-to-rise state, it is preparing for the rise. For example, in the ready-to-rise state, the power-on video is ready, and the follow-up animation is ready. At this time, the controller 11 controls the screen 201 to remain in the preset reference position, that is, the screen 201 remains at the reference point position. In this way, the screen 201 can directly enter the rising ready state from the zero state, ensuring that the screen 201 continues to move further, and then ensuring that the screen 201 synchronously follows the rise.

[0077] After the screen 201 successfully switches to the ready-to-rise state, it means that the screen 201 is ready to rise. Figure 6According to the state switching mechanism, the next state of the ready-to-rise state is the rising state, which means that the ready-to-rise state is the first state, and the rising state is the second state, and the control screen 201 is further switched from the ready-to-rise state to the rising state. At the same time, according to the rising instruction stored in the storage element, the control screen 201 starts to rise, and the control screen 201 keeps the rising action until the screen 201 moves from the reference point to the corresponding position of the top state. Here, the corresponding position of the top state can be the highest position that the screen 201 can move. In this way, the screen 201 can directly enter the rising state from the ready-to-rise state, ensuring that the screen 201 moves upward, and then ensuring that the screen 201 synchronously follows the rise.

[0078] In some embodiments, during the process of the screen 201 rising, if an obstacle is detected, Figure 6 The state switching mechanism is that the rising state is the first state, and the obstacle detection state is the second state, and the screen 201 is controlled to switch from the rising state to the obstacle detection state, and the screen 201 is controlled to pause the rising action. In this way, during the rising process of the screen 201, if an obstacle is detected, the screen 201 can be directly controlled to pause the rising. If it is detected that the obstacle is removed, according to Figure 6 The state switching mechanism is used to detect the obstacle state as the first state, the rising state as the second state, and control the screen 201 to switch from the obstacle detection state to the rising state, and control the screen 201 to continue the rising action. In this way, after clearing the obstacle, the screen 201 can continue to rise directly.

[0079] In some embodiments, obstacles can be detected by using distance sensors, photoelectric sensors and other technical means, or by installing an image collector to collect images, which can be a camera. The controller obtains the screen image captured from the camera to determine whether there is an obstacle that hinders the movement of the screen. An image of the screen can be captured at a preset interval, and the images captured before and after the adjacent time are compared, and whether there is an obstacle is determined based on the comparison result.

[0080] The number of cameras may be one or more, wherein at least one camera has a camera area for the lifting screen area, and the camera is used to take photos of the screen and the displayed image during the lifting process. When the number of cameras is two, the two cameras are respectively arranged on both sides of the projection assembly. In some embodiments, the camera can rotate in the horizontal plane, and when it is necessary to take photos of the screen and the displayed image, the camera lens is rotated to the screen direction; when it is necessary to take photos of the user, the camera lens is rotated to the user.

[0081] For example, Figure 8The two screen images a and b are shown. The two screen images a and b are images taken at adjacent times. The shooting time of b is later than that of a. The image b has more Figure 8 The shaded area of ​​the dotted line area is shown. It can be determined that there is an obstacle that hinders the movement of the screen. In addition, a blower can be set near the screen to remove light obstacles around the screen. For example, the blower can easily remove paper scraps. The blower does not need to be set to normally open, and the blower can be turned on when an obstacle is detected.

[0082] For example, image b now has an additional Figure 8 The shadow of the dotted area is shown. The camera sends the obstacle detection signal to the controller, and the controller controls the blowing device to turn on. After the blowing device is turned on for a preset time, the screen image b1 is photographed again. If the shadow of the dotted area of ​​screen image b1 is eliminated relative to screen image a, it means that the obstacle has been removed and may be lighter in weight, and will no longer hinder the movement of the screen. If the dotted area of ​​screen image b1 is not eliminated relative to screen image a, it means that the obstacle is heavier in weight and is not easy to remove, and will still hinder the movement of the screen. Fig. 9 As shown, if the dotted area in the screen image b1 moves relative to the dotted area in the screen image b, it can also indicate that the obstacle is light and no longer hinders the movement of the screen. The above-mentioned method of taking images can not only determine whether there are obstacles around the screen, but also obtain the exact location of the obstacles, so that the user can easily remove the obstacles.

[0083] In some embodiments, when an obstacle that hinders the movement of the screen is detected, the speaker can also be controlled to issue a voice reminder to remove the obstacle, so that the user can be informed that there are obstacles around the screen, which may cause the screen to be unable to move normally, and thus ensure that the screen can be raised and lowered normally by removing the obstacle.

[0084] In some embodiments, such as Figure 6 As shown, in the state switching mechanism, if the current state of the screen 201 is the top state, the laser projection device 202 is in the power-on state. Similarly, this embodiment only considers the normal power-on and power-off scenario, that is, when the current state of the screen 201 is the top state, the laser projection device 202 can only be in the power-on state, and does not consider the abnormal power-off situation (for example, when the current state of the screen 201 is the top state, the laser projection device 202 is powered off, causing the screen 201 to be unable to descend).

[0085] While the current state of the screen 201 is the top state, a shutdown command input by the user is received. According to the state sequence relationship in the state switching mechanism, the next state of the top state is the ready-to-descend state, which means that the top state is the first state and the ready-to-descend state is the second state, then the screen 201 is controlled to switch from the top state to the ready-to-descend state, and a start-to-descend command is generated. It should be noted that after the descent command is generated, the descent command is temporarily stored in the storage element, and at this time the screen 201 is not controlled to perform a corresponding action according to the descent command. At this time, the controller 11 controls the screen 201 to remain at the preset reference position, that is, the screen 201 remains at the reference point position. In this way, the screen 201 can directly enter the ready-to-descend state from the top state, ensuring that the screen 201 continues to move further, thereby ensuring that the screen 201 synchronously follows the descent.

[0086] After the screen 201 successfully switches to the ready-to-descend state, it means that the screen 201 is ready to descend. Figure 6 According to the state switching mechanism, the next state of the ready-to-descend state is the descending state, indicating that the ready-to-descend state is the first state, and the descending state is the second state, and the control screen 201 is further switched from the ready-to-descend state to the descending state. At the same time, according to the descending instruction stored in the storage element, the control screen 201 starts to descend, and the control screen 201 keeps descending until the screen 201 moves from the highest position to the corresponding position of the bottom state. Here, the corresponding position of the bottom state can be the lowest position where the screen 201 can move. In this way, the screen 201 can directly enter the descending state from the ready-to-descend state, ensuring that the screen 201 moves downward, and then ensuring that the screen 201 synchronously follows the descent.

[0087] In some embodiments, during the descent of the screen 201, if an obstacle is detected, Figure 6 The state switching mechanism is that the descending state is the first state, and the obstacle detection state is the second state, and the screen 201 is controlled to switch from the descending state to the obstacle detection state, and the screen 201 is controlled to pause the descending action. In this way, during the descending process of the screen 201, if an obstacle is detected, the screen 201 can be directly controlled to pause the descent. If it is detected that the obstacle is removed, according to Figure 5 The state switching mechanism detects the obstacle state as the first state, the descending state as the second state, controls the screen 201 to switch from the obstacle detection state to the descending state, and controls the screen 201 to continue the descending action. In this way, after the obstacle is cleared, the screen 201 can continue to descend directly.

[0088] In the state switching mechanism of the above embodiment, the specific description of each state in the lifting process and the conditions for state transition in and out can be expressed as shown in Table 1:

[0089]

[0090]

[0091] Table 1 Description of each state and conditions for transition in and out of the state switching mechanism

[0092] Among them, the MCU (Micro Controller Unit) in Table 1 is a microcontroller component, also known as a microcontroller.

[0093] The specific implementation process of the above embodiment can be as follows:

[0094] When booting, if Fig.10 The process shown in the state switching signaling diagram is shown. When the Android system starts home (application), Activitymanagerservice (the service responsible for managing all activities in the system) starts hisplayerservice (background service) first according to the scene judgment. After hisplayservice is started, a state switching module is created during initialization. The state switching module initializes communication with the MCU, reads the screen 201 status, and initializes the status to BOTTOM status (bottom status) when the power is on. hisplayservice sends a power-on command, and after the state switching module receives the power-on command, it performs subsequent state switching according to the state switching mechanism.

[0095] When shutting down, Fig.11 The process shown in the state switching signaling diagram is shown. Shutdownmanagerservice (shutdown management service) receives the shutdown button command and starts the hisplayservice background service. Hisplayservice creates a state initialization module during the onstart (event handler triggered when text starts to display) life cycle. The state switching module communicates with the MCU serial port to read the status of screen 201. In the case of normal shutdown, the status of screen 201 is TOP (top status). Hisplayservice sends a shutdown command. After receiving the command, the state switching module performs subsequent state switching according to the state switching mechanism.

[0096] When the screen 201 is raised or lowered, if an obstacle is detected, Fig.12The process is shown in the state switching signaling diagram shown. Obstacle detection thread: 1s polling to read GPIO (General Purpose Input Output, which refers to the chip pins in the embodiment of the present invention), then obtain the state of the obstacle, and notify the lifting UI processing thread of the reading result. UI processing thread: When an obstacle is detected during the ascent and descent process, it enters pending (obstacle detected state), notifies the MCU to pause the lifting of the screen 201, and stops the animation following. After the obstacle is removed, remove the pending state, notify the MCU to continue the movement of the screen 201, and the picture follows the movement synchronously. Receive the status message of the state machine and perform related operations. Lifting state machine: manages the switching of the various states of the lifting of the screen 201, the lifting and pausing of the screen 201, and interacts with the MCU through serial port communication, and sends corresponding instructions to control the lifting of the screen 201.

[0097] In some embodiments, after the controller controls the screen to switch state successfully, it can prompt the user that the state switch is successful through an indicator light or a screen flashing. For example, when the screen successfully switches from the bottom state to the zero state, and when the screen moves from the lowest point to the reference point, the screen flashes regularly for a predetermined time. In actual applications, it may also happen that the screen has not moved to the highest point, or has not moved to the lowest point, and the user mistakenly thinks that the screen has moved to the highest point or the lowest point. That is, the user mistakenly thinks that the state switch is successful, so the user can be reminded through a successful state switch indication. For example, when the screen rises, it does not rise to the highest point due to factors such as failures, but the user cannot judge whether it has risen to the highest point with the naked eye. Therefore, if the screen is set to successfully switch from the rising state to the top state, that is, the screen successfully rises to the highest point position, the screen flashes regularly. If the screen does not flash regularly, it means that the screen state switch is unsuccessful, thereby avoiding the above-mentioned situation where it is impossible to judge whether the state switch is successful.

[0098] In some embodiments, when the rising state is switched to the top state, since it takes a certain time to move from the reference point position to the top highest point position, in order to avoid abnormal situations in the middle due to too long time, an intermediate state can also be set during the rising process. For example, an rising intermediate state is set between the rising state and the top state. After the rising state is successfully switched to the rising intermediate state, it is switched from the rising intermediate state to the top state. Similarly, when the falling state is switched to the bottom state, since it takes a certain time to move from the top highest point position to the bottom lowest point position, in order to avoid abnormal situations in the middle due to too long time, an intermediate state can also be set during the falling process. For example, a falling intermediate state is set between the falling state and the bottom state. After the top state is successfully switched to the falling intermediate state, it is switched from the falling intermediate state to the bottom state. In this way, the rising stage and the falling stage with longer time are refined to reduce the occurrence of abnormal situations in these stage state switching.

[0099] In some embodiments, a custom state can also be set between the rising state and the top state. For example, the user does not want to raise the screen to the highest point, that is, to a position between the lowest point and the highest point. A custom button can be set on the control device. Specifically, when the screen is rising, the user inputs a custom instruction by pressing a custom button on the control device, and the controller receives the custom instruction, controls the screen to switch from the bottom state to the custom state according to the custom instruction, and controls the screen to move from the lowest point to the corresponding position of the custom state.

[0100] Here, the position corresponding to the custom state can be preset to one or multiple. When there are multiple positions corresponding to the custom state, after receiving the custom instruction, the controller can control the device voice prompt to select the number of the custom position. For example, prompt the user to select custom position 1 or custom position 2. Similarly, a custom state can also be set between the descending state and the bottom state. During the descent of the screen, the user inputs a custom instruction by pressing a custom button on the control device. The controller receives the custom instruction and controls the screen to switch from the top state to the custom state according to the custom instruction, and at the same time controls the screen to move from the highest point to the corresponding position of the custom state. In this way, using the custom state, the user can control the screen to move to the position he needs to use through the control device.

[0101] Fig.13 A signaling diagram of a method for switching the lifting state of a screen 201 of a laser projection device 202 provided in an embodiment of the present invention is applied to the laser projection device 202. The laser projection device 202 includes a monitoring component configured to monitor the current state of the screen 201. The screen 201 is a liftable screen 201. The state of the screen 201 is a state preset in a state switching mechanism. The state switching mechanism is a preset mechanism. The screen 201 switches the current state according to the state switching mechanism. The method is applied to the controller 11 of the laser projection device 202, and specifically includes the following steps:

[0102] Step 1: Obtain the current state of the screen 201 from the monitoring component;

[0103] Step 2: When the current state of the screen 201 is the first state, control the screen 201 to switch from the first state to the second state. It should be noted that the first state and the second state are both states specified in the state switching mechanism. In the state switching mechanism, the second state is the next state of the first state.

[0104] Step three: controlling the screen 201 to execute the operation corresponding to the second state.

[0105] In this way, the controller can use the preset state switching mechanism according to the current state of the screen 201 to determine the relationship between the current state of the screen 201 and other states in the state switching mechanism (a sequential relationship in this embodiment). Directly control the screen 201 to switch from the current state to the state indicated in the state switching mechanism. Then, according to the state after switching, control the screen 201 to perform the operation corresponding to the state after switching. This ensures that when the laser projection device 202 is turned on and off, the screen 201 can synchronously follow the rise and fall, thereby improving the user's viewing experience.

[0106] In some embodiments, during the lifting and lowering process of the screen of the new form of laser TV, the projected image cannot rise and fall synchronously with the screen. In order to solve the above problem, based on the projection device architecture in the above embodiment, an embodiment of the present invention also provides a projection device, including: a projection component, configured to project an image onto the screen, and the screen is a liftable screen; a monitoring component, configured to monitor the moving height of the screen during the movement of the screen, and feedback the moving height to the controller; the controller is configured to: calculate the projection height according to the moving height using a preset rule, and the preset rule stipulates the mapping relationship between the moving height and the projection height; according to the projection height, control the projection component to project the corresponding height image onto the screen. The preset rule can specifically be a corresponding table for setting the screen moving height and the projection height. For example, if the screen moving height is 10cm, the projection height is also 10cm, or a specific value is set according to the actual situation of the screen.

[0107] The image following method and projection device provided in this embodiment monitor the moving height of the screen during the movement of the screen through a monitoring component. The screen is a screen that can be rolled up and raised. After receiving the moving height of the screen, the controller calculates the projection height according to the moving height using a preset rule. The preset rule specifies the mapping relationship between the moving height and the projection height. Finally, according to the projection height, the projection component is controlled to project an image of the corresponding height onto the screen. The embodiment of the present application can calculate the height of the image to be projected according to the moving height of the screen during the movement of the screen, so as to achieve the effect of the image rising and falling synchronously with the screen, thereby improving the user viewing experience.

[0108] In some embodiments, if the screen is in the rising state, the rising height of the screen is obtained, and the rising height is determined as the moving height. When the screen is in the rising state, the moving direction of the screen is from the lowest point to the highest point; the percentage of the moving height to the full height is calculated, and the full height is the height from the screen rising to the highest point. When the screen rises to the highest point, the image projected by the projection component to the screen is a complete image. The projection component is controlled to project the corresponding height image to the screen according to the percentage. For example, Fig.14 The projection diagram of the rising state shown and Fig.15In the complete projection diagram shown, the current screen is in the rising state, that is, the moving direction is from the lowest point to the highest point. The rising height of the screen from the lowest point to the highest point is H, which means that the moving height of the screen is also H. The complete height is W. The percentage of the screen rising at this time is H / W. The image is projected onto the screen according to the same percentage, that is, the height of the projection area L = H / W*Z, where Z is the height of the image when the projection component projects the complete image onto the screen.

[0109] In some embodiments, when the state of the screen is an obstacle detected state, the projection component is controlled to stop projecting images to the screen, and when the state of the screen is an obstacle detected state, the screen stops moving.

[0110] In some embodiments, when the screen is in a descending state, the descending height of the screen is obtained, and the value of the complete height minus the descending height is determined as the moving height, the complete height is the height when the screen rises to the highest point, when the screen rises to the highest point, the image projected by the projection component onto the screen is a complete image, and when the screen is in a descending state, the moving direction of the screen is from the highest point to the lowest point; the percentage of the moving height to the complete height is calculated; and the projection component is controlled to project an image of corresponding height onto the screen according to the percentage.

[0111] For example, Fig.16 In the schematic diagram of the projection in the descending state shown in the figure, the current screen is in the descending state, that is, the moving direction is from the highest point to the lowest point. The descending height of the screen from the highest point to the highest point is M, which means that the moving height of the screen is also WM. The percentage of the screen rising at this time is WM / W. The image is projected onto the screen according to the same percentage, that is, the height of the projection area L = WM / W*Z.

[0112] In some embodiments, the projected image may be a video animation, which is implemented by TextureView (a UI control for displaying data streams) + MediaPlayer (media center software). Specifically, TextureView is used to control the height of the screen, and MediaPlayer is used to control the playback of the screen. The specific implementation mechanism of the screen rise embodiment is:

[0113] When starting to rise, set the Y-axis value of TextureView (that is, the height value of the rising animation) to the initial state, call the start interface of MediaPlayer to start playing the video animation, and notify the MCU to start the screen rising through serial communication.

[0114] When the screen is in the rising state (in the rising process), the monitoring component (lifting state machine) communicates with the MCU through the serial port and polls the percentage of the screen's rising height (that is, the percentage of the moving height to the full height). The height percentage is then notified to the UI processing thread, which converts the height percentage into the Y-axis value of TextureView. According to the Y-axis value of TextureView, the projection component is controlled to project the corresponding area of ​​the video screen (that is, the screen with the corresponding Y value height) onto the screen. The above mechanism is used to achieve the following of video animation and screen.

[0115] If the obstacle thread detects an obstacle, it enters the pause state (obstacle detected state) through the lifting state machine. The lifting state machine notifies the MCU to pause the screen lifting action through serial communication, and notifies the UI processing thread to process the animation related logic. Specifically, after the UI processing thread receives the obstacle detection message, it calls the pause method to pause the video animation and stops updating the Y axis value of TextureView.

[0116] If the obstacle thread detects that the obstacle disappears, it notifies the lifting state machine of the disappearance of the obstacle, and the lifting state machine returns to the rising state. The lifting state machine notifies the MCU through serial communication to continue to raise the screen, and notifies the UI processing thread to continue processing animation-related logic. After receiving the message, the UI processing thread calls the Start method to continue playing the video animation. The lifting state machine communicates with the MCU through serial communication and continues to poll to obtain the percentage of the screen rising height. And notify the UI processing thread of the obtained screen rising height percentage. The UI processing thread converts the rising height percentage into the Y-axis value of TextureView, and then continues to adjust the Y-axis value of TextureView to achieve the synchronous follow-up of the video animation and screen lifting.

[0117] Fig.17 A signaling schematic diagram of an image following method when the screen of a projection device is raised or lowered provided in an embodiment of the present invention is applied to a projection device, wherein the projection device includes a projection component configured to project an image onto a screen, wherein the screen is a liftable screen; and a monitoring component configured to monitor the moving height of the screen during the movement of the screen, and to feed back the moving height to a controller, specifically including the following steps:

[0118] Step 1: Calculate the projection height according to the moving height using a preset rule, wherein the preset rule specifies a mapping relationship between the moving height and the projection height;

[0119] Step 2: According to the projection height, control the projection component to project an image of corresponding height onto the screen.

[0120] Those skilled in the art will appreciate that the various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, the various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "controllers", "engines", "units", "components" or "systems". In addition, the various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0121] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0122] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

Claims

1. A projection device, characterized in that: include: A projection assembly, configured to project an image onto a screen, wherein the screen is a liftable screen; A monitoring component is configured to monitor the current state of the screen, and, during the movement of the screen, monitor the moving height of the screen and feed back the moving height to the controller; the state of the screen refers to a preset state currently corresponding to the screen, wherein the preset state refers to a pre-set motion state of the screen; The controller is configured to: In response to a first instruction, obtaining a current state of the screen through the monitoring component; Switching the state of the screen according to a state switching mechanism, wherein the state switching mechanism includes a sequential relationship of switching of the screen between the preset states; Controlling the screen to perform an operation corresponding to the state after switching; When the operation corresponding to the switched state includes moving a position, acquiring the moving height through the monitoring component; Calculating the percentage of the moving height to the complete height, the complete height being the height of the screen when it rises to the highest point, and when the screen rises to the highest point, the image projected by the projection component onto the screen is a complete image; Calculating a projection height according to the percentage and the height of the complete image; According to the projection height, the projection component is controlled to project an image of corresponding height onto the screen.

2. The projection device according to claim 1, characterized in that: The controller is specifically configured as follows: When the state of the screen is an obstacle detected state, the projection component is controlled to stop projecting images to the screen; when the state of the screen is an obstacle detected state, the screen stops moving.

3. The projection device according to claim 1, characterized in that: The controller is specifically configured as follows: When the state of the screen is in a descending state, the descending height of the screen is obtained, and a value obtained by subtracting the descending height from the full height is determined as the moving height, wherein the full height is the height of the screen when it rises to the highest point, and when the screen rises to the highest point, the image projected by the projection component to the screen is a complete image, and when the state of the screen is in a descending state, the moving direction of the screen is from the highest point to the lowest point; Calculate the percentage of the moving height to the complete height; The projection component is controlled to project an image of corresponding height onto the screen according to the percentage.

4. The projection device according to claim 1, characterized in that: The state of the screen includes a first state and a second state preset according to a state switching mechanism, and the controller is further configured to: Get the current state of the screen; When the current state of the screen is the first state, the screen is controlled to switch from the first state to the second state, and the screen is controlled to perform an operation corresponding to the second state, wherein in the state switching mechanism, the second state is the next state of the first state.

5. The projection device according to claim 4, characterized in that: The controller is further configured to: If the first instruction is a power-on instruction, when the first state is the bottom state, and the second state is the zero state, the screen is controlled to move from a position corresponding to the bottom state to a position corresponding to the zero state, when the state of the screen is the bottom state, the screen is located at the lowest point position that the screen can move, and when the state of the screen is the zero state, the screen is located at a preset reference position; When the first state is the zero state, the second state is the ready-to-rise state, the switching state simultaneously generates a start-to-rise instruction, and at the same time controls the screen to remain in the preset reference position. When the state of the screen is the ready-to-rise state, the screen is located at the preset reference position.

6. The projection device according to claim 5, characterized in that: The controller is further configured to: When the first state is a state of preparing to rise, the second state is a state of rising, and the state is switched simultaneously according to the start rising instruction, controlling the screen to start rising and maintain the rising action until the screen moves to a position corresponding to the top state, wherein when the state of the screen is a rising state, the moving direction of the screen is from the lowest point to the highest point, and when the state of the screen is a top state, the screen is located at the highest point where the screen can move.

7. The projection device according to claim 4, characterized in that: The controller is further configured to: If the first instruction is a shutdown instruction, in response to the shutdown instruction, when the first state is the top state, the second state is the ready-to-descend state, and the state is switched while generating a start-to-descend instruction, while controlling the screen to remain at the position corresponding to the top state. When the screen is in the top state and the ready-to-descend state, the screen is located at the highest point where the screen can move.

8. The projection device according to claim 7, characterized in that: The controller is further configured to: When the first state is a state of preparing to descend, the second state is a state of descending, and the state is switched simultaneously to control the screen to start descending and maintain the descending action according to the start descending instruction until the screen moves to a position corresponding to the bottom state. When the state of the screen is the bottom state, the screen is located at the lowest point where the screen can move.

9. A method for following images when the screen of a projection device is raised or lowered, characterized in that: The projection device comprises a projection component configured to project an image onto a screen, wherein the screen is a liftable screen; A monitoring component is configured to monitor the current state of the screen, and, during the movement of the screen, monitor the moving height of the screen and feed back the moving height to the controller, wherein the state of the screen refers to a preset state currently corresponding to the screen, wherein the preset state refers to a pre-set motion state of the screen; the method comprises: In response to a first instruction, obtaining a current state of the screen through the monitoring component; Switching the state of the screen according to a state switching mechanism, wherein the state switching mechanism includes a sequential relationship of switching of the screen between the preset states; Controlling the screen to perform an operation corresponding to the state after switching; When the operation corresponding to the switched state includes moving a position, acquiring the moving height through the monitoring component; Calculating the percentage of the moving height to the complete height, the complete height being the height of the screen when it rises to the highest point, and when the screen rises to the highest point, the image projected by the projection component onto the screen is a complete image; Calculating a projection height according to the percentage and the height of the complete image; According to the projection height, the projection component is controlled to project an image of corresponding height onto the screen.

Images