Projection system

Abstract

The utility model discloses a projection system, which comprises projection equipment, a transmission mechanism, a first sensor and a controller, the transmission mechanism is installed on the projection equipment, and the transmission mechanism drives at least part of the structure of the projection equipment to move; the first sensor is installed on the projection equipment and detects displacement generated by at least part of the structure of the projection equipment. The controller is located in the projection device and connected with the first sensor. The first sensor can detect the displacement generated by at least part of the structure of the projection equipment in real time, and the controller determines the displacement which the transmission mechanism needs to move according to the displacement information, so that the transmission mechanism is driven to move. A closed-loop feedback loop is formed among the first sensor, the controller and the transmission mechanism, so that the moving precision of the transmission mechanism can be improved, and human intervention is not needed.

Description

Technical Field

[0001] This utility model relates to the field of projection technology, and in particular to a projection system. Background Technology

[0002] A laser TV is a display device that uses a laser light source as its display light source and combines it with projection display technology to create an image. To improve picture quality, laser TVs are usually equipped with a dedicated projection screen and can receive broadcast television programs or internet television programs.

[0003] The current transmission mechanisms used in laser TVs employ limit switches, which can only restrict approximate positions and cannot provide precise control, requiring manual intervention. After the motor-driven structure completes its movement, manual adjustments are still necessary, and the adjustment steps must be updated in the software, making the process quite cumbersome. Utility Model Content

[0004] This utility model provides a projection system that can improve displacement detection accuracy without manual intervention.

[0005] The projection system provided in this embodiment of the utility model includes:

[0006] Projection equipment;

[0007] A transmission mechanism is installed on the projection device; the transmission mechanism drives at least a portion of the structure of the projection device to move.

[0008] A first sensor is mounted on the projection device; the first sensor detects displacements generated by at least a portion of the structure of the projection device.

[0009] A controller, located inside the projection device and connected to the first sensor, drives the transmission mechanism based on the detected displacement to move at least a portion of the projection device to the target position.

[0010] In some embodiments of this utility model, the projection system further includes:

[0011] The second sensor detects the resistance experienced by the transmission mechanism.

[0012] The controller adjusts the transmission speed of the transmission mechanism based on the detected resistance.

[0013] In some embodiments of this utility model, the projection device includes a housing with an opening and a sliding cover at the opening. The transmission mechanism is connected to the sliding cover to drive the sliding cover to slide at the opening.

[0014] The first sensor includes: an identification unit and a sensing unit; the identification unit and the sensing unit are respectively disposed on the edge of the opening and on the sliding cover; the sensing unit is connected to the controller;

[0015] The second sensor is mounted on the transmission mechanism or the sliding cover.

[0016] In some embodiments of this utility model, the controller controls the sliding cover to close;

[0017] The first sensor detects the displacement of the sliding cover;

[0018] The second sensor detects the resistance experienced by the sliding cover;

[0019] The controller determines the current position of the sliding cover based on the displacement of the sliding cover, compares the current position of the sliding cover with the target position, and when the current position of the sliding cover is inconsistent with the target position, calculates the displacement that the sliding cover needs to move, and controls the sliding cover to move according to the calculated displacement until the sliding cover moves to the target position.

[0020] The controller adjusts the sliding cover's moving speed based on the resistance it experiences and a pre-stored correspondence between resistance and speed; when the resistance experienced by the sliding cover exceeds a preset threshold, the controller stops the sliding cover from moving and issues an alarm.

[0021] In some embodiments of this utility model, the projection device includes a housing and a lens, the housing has an opening, and the lens is located inside the housing; the transmission mechanism is connected to the lens to drive the lens to extend out or retract from the opening;

[0022] The first sensor includes an identification unit and a sensing unit; the identification unit is disposed on the housing, the sensing unit is disposed on the lens or the transmission mechanism, and the sensing unit is connected to the controller.

[0023] In some embodiments of this utility model, the projection system further includes: a screen; the projection device is mounted on a pan-tilt unit, and the transmission mechanism is connected to the pan-tilt unit to drive the pan-tilt unit to move to a fixed position relative to the screen;

[0024] The first sensor includes: an identification unit and a sensing unit; the identification unit is disposed on the screen or near the screen; the sensing unit is disposed on the gimbal and is connected to the controller;

[0025] The second sensor is mounted on the transmission mechanism or the pan-tilt unit.

[0026] In some embodiments of this utility model, the projection system further includes: a screen; the transmission mechanism is connected to the screen to drive the screen to retract or unfold;

[0027] The second sensor is mounted on the transmission mechanism or the screen.

[0028] In some embodiments of this invention, the first sensor and the second sensor are fixed by embedding or locking.

[0029] In some embodiments of this invention, the first sensor is a displacement sensor; the second sensor is a pressure sensor.

[0030] In some embodiments of this utility model, the projection system further includes:

[0031] Signal conversion circuit, connected to the sensor;

[0032] An operational amplifier circuit is connected to the signal conversion circuit.

[0033] A filter output circuit is connected to the operational amplifier circuit.

[0034] The filter output circuit is connected to the controller.

[0035] The projection system provided in this embodiment includes: a projection device, a transmission mechanism, a first sensor, and a controller. The transmission mechanism is installed on the projection device and drives at least a portion of the projection device's structure to move. The first sensor is installed on the projection device and detects the displacement generated by at least a portion of the projection device's structure. The controller is located inside the projection device and connected to the first sensor. The first sensor can detect the displacement generated by at least a portion of the projection device's structure in real time, and the controller determines the remaining displacement of the transmission mechanism based on this displacement information, thereby driving the transmission mechanism to move. A closed-loop feedback circuit is formed between the first sensor, the controller, and the transmission mechanism, thereby improving the movement accuracy of the transmission mechanism without requiring human intervention. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 One of the schematic diagrams of the projection system provided in the embodiment of this utility model;

[0038] Figure 2A schematic diagram of the functional architecture of the projection system provided in this embodiment of the utility model;

[0039] Figure 3 One of the schematic diagrams of the projection system provided in the embodiment of this utility model;

[0040] Figure 4 A flowchart for position detection provided in this embodiment of the utility model;

[0041] Figure 5 A second schematic diagram of the architecture of the projection system provided in this embodiment of the utility model;

[0042] Figure 6 A flowchart for pressure detection provided in this embodiment of the utility model;

[0043] Figure 7 The third schematic diagram of the projection system provided in this embodiment of the utility model;

[0044] Figure 8 A schematic diagram of the principle of the first sensor provided in an embodiment of this utility model;

[0045] Figure 9 A schematic diagram of the structure of the projection device provided in the embodiment of this utility model;

[0046] Figure 10 This is a partially enlarged schematic diagram of the projection device provided in an embodiment of the present utility model;

[0047] Figure 11 A flowchart for sliding cover detection provided in this embodiment of the utility model;

[0048] Figure 12 A second schematic diagram of the projection system provided in this embodiment of the present utility model;

[0049] Figure 13 A schematic diagram of the screen structure provided for an embodiment of this utility model. Detailed Implementation

[0050] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the utility model more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in this utility model are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this utility model. The accompanying drawings of this utility model are for illustrating relative positional relationships only and do not represent actual proportions.

[0051] With the increasing popularity of laser display products, the market for laser TVs, as a large-screen alternative to LCD and OLED TVs, is rapidly expanding. To achieve better brightness and display effects, projection devices are generally used in conjunction with projection screens.

[0052] like Figure 1 As shown, the projection system includes a projection device 11 and a screen 22.

[0053] Screen 22 is located on the light-emitting side of projection device 11, and the viewer faces screen 22. Projection device 11 emits projection light, which enters screen 22, passes through screen 22, and exits towards the viewer, thus allowing the viewer to see the projected image.

[0054] When the projector 11 and the viewer are located on the same side of the screen 22, this projection system is called a front projection system. When the projector 11 and the viewer are located on opposite sides of the screen 22, this projection system is called a rear projection system. In a front projection system, the projector 11 emits projection light onto the screen 22, and the screen 22 reflects the projection light back to the viewer, allowing the viewer to see the projected image. In a rear projection system, the projector 11 emits projection light onto the screen 22, and the projection light passes through the screen 22 and is emitted back to the viewer, allowing the viewer to see the projected image.

[0055] The functional architecture of the projection system can be referenced. Figure 2 ,like Figure 2 As shown, the projection system includes a multimedia unit, an image processing unit, and a power supply module. The power supply module provides power to the multimedia unit, image processing unit, and other functional modules. The power supply module also has a voltage conversion function, allowing it to output the appropriate power voltage according to the needs of each functional module. For example, the power supply module can provide 12V to the multimedia unit and image processing unit, and 24V to the light source driving module.

[0056] The multimedia unit includes a main chip and a control system. The main chip, as the core component of the projection system, is responsible for receiving and processing signals from different modules. The main chip is connected to a storage module to store system settings, user preferences, and processed data.

[0057] The multimedia unit may also include functional modules such as an infrared receiver module and a wireless voice module, the latter of which can connect to a speaker. The infrared receiver module and wireless voice module are used for user interaction. Users can control the projection system using devices such as remote controls. The infrared receiver module receives control signals from the remote control and uses these signals to instruct the projection system to perform corresponding operations. The wireless voice module converts information from the projection system into speech, which is then played through the speaker, improving the convenience of user interaction and making operation more intuitive and faster.

[0058] Both the infrared receiving module and the wireless voice module are connected to the main chip through the control system. The control system collects and receives information and sends it to the main chip for processing. The main chip then sends control signals to the control system, which processes the control signals accordingly to trigger the corresponding modules to perform their respective functions.

[0059] The multimedia unit and the image processing unit communicate via a dedicated interface. The multimedia unit can transmit image data to the image processing unit, and control signals can be transmitted between the image processing unit and the multimedia unit.

[0060] The image processing unit mainly includes: a Digital Light Processing (DLP) driver control module, an MCU control module, and a storage module. The MCU control module is connected to the DLP driver control module. The DLP driver control module is also connected to the image display module and the light source driver module, and the light source driver module is connected to the light source module.

[0061] The projection system provided in this embodiment can be a laser television, employing a DLP architecture for image display. The image display module in the DLP system can utilize a Digital Micromirror Device (DMD). A DMD is an optical device based on Micro-Electro-Mechanical Systems (MEMS) technology. The DMD includes an array of miniature mirrors. A light source illuminates the array of miniature mirrors, and the tilt direction of the mirrors determines the direction of light reflection. By precisely controlling the tilt state of each miniature mirror, the DMD can achieve spatial and temporal modulation of light, thereby generating the desired image.

[0062] The DLP drive control module receives image data transmitted from the multimedia unit, processes the image data into image drive data to drive the image display module, and sends it to the image display module. Simultaneously, it needs to coordinate with the control of the light source. Therefore, it can generate light source drive data based on the image data and send it to the light source drive module. The light source drive data can include: an enable control signal (L_EN), duty cycle signals for the three primary colors (R_DUTY, G_DUTY, B_DUTY), and pulse width modulation signals (R_PWM, G_PWM, B_PWM).

[0063] The MCU control module can handle more complex image processing tasks, such as keystone correction and dynamic contrast adjustment. The collaborative work of these modules ensures the sharpness and color accuracy of the projected image, meeting users' demands for a high-quality visual experience.

[0064] In addition, the MCU control module can be connected to an ambient temperature sensor to detect the surrounding temperature. The light source module can also be equipped with a temperature sensor to detect its own temperature. The MCU control module's monitoring of both the light source module and ambient temperature ensures the projection system operates within a safe temperature range. Based on the detected temperature, the MCU control module can adjust the fan speed or issue a warning.

[0065] like Figure 2 As shown, projection systems require transmission mechanisms in many locations to achieve automatic control. These transmission mechanisms need to be connected to sensors to detect their status; however, the sensors currently used in projection systems are typically limit switches, which are photoelectric sensors.

[0066] A photoelectric limit switch is a device that controls the operation of mechanical or electrical equipment by detecting the position of an object. A photoelectric limit switch consists of a transmitter and a receiver. The transmitter emits an infrared beam, and the receiver receives the beam. When an object blocks the beam, the receiver cannot receive it, thus controlling the switch's output state.

[0067] In photoelectric limit switches, the transmitter typically uses an infrared light source. When current flows through the transmitter, it emits an invisible infrared beam. This beam travels in a straight line through the air. After traveling a certain distance, the beam encounters the object being measured. When the object enters the beam's range, it blocks the beam, preventing the receiver from receiving it. The receiver is positioned opposite the transmitter, receiving the infrared beam at a fixed angle. When the beam is blocked, the receiver cannot receive the infrared light, and the receiver in the circuit becomes either on or off. The photoelectric limit switch changes its output signal based on whether the receiver receives the beam. When the object blocks the beam, the output state changes, allowing the output signal to be connected to other devices for control of mechanical or electrical equipment.

[0068] Photoelectric limit switches change the output state by using objects to block light, so the size of the detection contact will affect the detection accuracy. Secondly, structural errors in the transmission mechanism will cause the end position of the stroke to be inconsistent with the expectation. After the transmission mechanism has moved according to the set program, it is necessary to manually adjust it and update the adjustment steps in the software, which is a rather cumbersome process.

[0069] In view of this, the present invention provides a projection system that can improve the movement accuracy of the transmission mechanism without the need for manual intervention.

[0070] like Figure 3 As shown, the projection system provided in this embodiment of the present invention includes: a projection device 11, a transmission mechanism 12, a first sensor 13, and a controller 14.

[0071] The projection system provided in this embodiment can be a laser TV, and various application scenarios of laser TVs all require the use of a transmission mechanism.

[0072] In some embodiments, the projection device may include a housing, within which the light source, processing elements, and imaging elements of the projection system are all housed. The housing is a sealed structure that protects the internal components from damage. When the projection system is powered on, a sliding cover at the opening of the housing automatically opens, allowing the imaging elements, such as the lens, to extend from the housing to a designated position for imaging. When the projection system is powered off, the lens retracts back into the housing, the sliding cover closes, and the housing remains sealed.

[0073] In some embodiments, the screen 22 can be housed within a housing, with the housing opening and the screen rising to a designated position when the projection system is powered on. When the projection system is powered off, the screen 22 retracts back into the housing.

[0074] In some embodiments, the screen 22 can also be stored in a fixed wall or hung high up. The top of the screen 22 can be connected to a scroll, which can roll up the screen 22 for storage or unfold it for projection.

[0075] In all the aforementioned mobile application scenarios, a transmission mechanism is required. In this embodiment of the invention, the transmission mechanism can be a motor, which also needs to be connected to a motor drive circuit. The transmission mechanism 12 is mounted on the projection device 11, and the transmission mechanism 12 can drive at least a portion of the structure of the projection device 11 to move.

[0076] Meanwhile, a first sensor 13 is also provided near the transmission mechanism. The first sensor 13 can be installed on the projection device 11. The first sensor 13 can detect the displacement of at least part of the structure of the projection device under the drive of the transmission mechanism.

[0077] The first sensor 13 is connected to the controller 14. The controller 14 can be located inside the projection device 11. The controller 14 can be the main chip in the multimedia unit, or a separate processing chip can be set as the controller 14 and then connected to the main chip.

[0078] The first sensor 13 can send the detected displacement information to the controller 14 in real time. The controller 14 determines the remaining displacement of the transmission mechanism based on the displacement information, thereby driving the transmission mechanism to move. A closed-loop feedback circuit is formed between the first sensor 13, the controller 14, and the transmission mechanism 12, thus improving the movement accuracy of the transmission mechanism without the need for human intervention.

[0079] Specifically, such as Figure 4 As shown, when the transmission mechanism moves the projection device, the controller executes the following steps:

[0080] S101, The controller drives the transmission mechanism to move the projection device;

[0081] S102, The first sensor detects the displacement generated by the transmission mechanism driving the projection device;

[0082] S103. The controller determines the drive data of the transmission mechanism based on the detected displacement.

[0083] S104. The controller drives the transmission mechanism according to the determined drive data.

[0084] In practical implementation, the aforementioned transmission mechanism can be a motor. The drive data determined by the controller can be a PWM signal, used to drive the motor to rotate a set number of steps. The transmission mechanism can move at least part of the projection device's structure or the entire projection device. Based on the detected displacement, the controller can determine the displacement that the projection device needs to move relative to the target position, and then use an algorithm embedded within the controller to determine the drive data for the transmission mechanism. The entire process requires no manual intervention.

[0085] The transmission mechanism may be obstructed during movement; in such cases, continued movement could lead to damage. To address this issue, such as... Figure 5 As shown, the projection system may further include a second sensor 15; the second sensor 15 is connected to the controller 14 and is used to detect the resistance experienced by the transmission mechanism 12. The controller 15 can also adjust the transmission speed of the transmission mechanism 12 according to the detected resistance to avoid damage.

[0086] Specifically, such as Figure 6 As shown, when the transmission mechanism moves the projection device, the controller can also perform the following steps:

[0087] S201, The controller drives the transmission mechanism to move the projection equipment.

[0088] S202, The second sensor detects the resistance experienced by the transmission mechanism;

[0089] S203. The controller adjusts the transmission speed of the transmission mechanism based on the detected resistance.

[0090] In practical implementation, the controller can pre-store the correspondence between resistance and transmission speed. This way, when the transmission mechanism drives the projection device to move, the resistance encountered by the transmission mechanism can be detected in real time, thereby adjusting the transmission speed of the transmission mechanism. When the resistance exceeds the set threshold, the transmission mechanism can be controlled to stop moving in time.

[0091] In this embodiment of the invention, the first sensor 13 can be a displacement sensor; the second sensor 15 can be a pressure sensor. Figure 7 As shown, regardless of the type of sensor used, a signal conversion circuit, an operational amplifier circuit, and a filter output circuit need to be connected to the sensor before it can be connected to the controller. The signal conversion circuit converts the AC voltage signal output by the sensor into a DC voltage signal; the operational amplifier circuit and the filter output circuit amplify and filter the converted signal, enabling the controller to receive and process it more effectively.

[0092] For displacement sensors, inductive sensors can be used. For example... Figure 8 As shown, the inductive sensor can be composed of three parts: a coil, an iron core, and an armature. The coil is wound around the iron core and generates inductance when energized. There is an air gap with a thickness of δ between the iron core (132) and the armature (131). When the armature moves, the thickness of the air gap changes by ±Δδ, which causes a change in the inductance of the coil. By measuring the change in inductance, the magnitude and direction of the armature displacement can be determined.

[0093] Specifically, according to and We can obtain:

[0094] L=N 2 / R m

[0095]

[0096] It can be approximated as:

[0097]

[0098] Therefore, we can conclude that:

[0099]

[0100] Where N represents the number of coil turns, and I represents the current. R represents the magnetic flux of the magnetic circuit. m The total magnetic reluctance of the magnetic circuit is represented by A0, the effective cross-sectional area of ​​the air gap is represented by A1, the cross-sectional area of ​​the iron core is represented by A2, the cross-sectional area of ​​the armature is represented by μ0, the permeability of air is represented by μ1, the permeability of the iron core is represented by μ2, the permeability of the armature is represented by δ, the thickness of the air gap is represented by l1, the length of the iron core is represented by l2, and the length of the armature is represented by l2.

[0101] Inductive sensors can determine the amount of displacement by detecting changes in inductance, and they have high detection accuracy, making them suitable for use in projection systems.

[0102] Pressure sensors come in various types, including strain gauge pressure sensors, piezoelectric pressure sensors, capacitive pressure sensors, piezoresistive pressure sensors, and Hall effect pressure sensors. The principles of each type will not be elaborated here. When applied to projection systems, a suitable pressure sensor can be selected based on the specific structure; no limitations are set here.

[0103] This embodiment of the invention uses an inductive sensor as an example to illustrate different application scenarios in a projection system. In different application scenarios, the first sensor and the second sensor described above can be used simultaneously, or only one of the two sensors can be used.

[0104] As described above, the displacement detected by the inductive sensor is the relative displacement between the iron core and the armature. Therefore, the inductive sensor can be divided into two parts: an identification unit 131 and a sensing unit 132. The identification unit 131 is the armature, which is usually made of metal. The sensing unit 132 is an iron core with a coil wound around it, which is connected to the controller 14. The distance between the identification unit 131 and the sensing unit 132 can be determined based on the detected inductance.

[0105] In some embodiments, such as Figure 9 As shown, the projection device includes a housing 111, which has an opening k. A sliding cover 112 is provided at the opening k. A transmission mechanism (located inside the housing, not shown in the figure) is connected to the sliding cover 112 to drive the sliding cover 112 to slide at the opening k.

[0106] The identification unit 131 and sensing unit 132 of the first sensor can be respectively disposed on the edge of the opening k and on the sliding cover 112. The distance between the identification unit 131 and sensing unit 132 changes when the sliding cover slides. The second sensor can be mounted on the transmission mechanism or the sliding cover to detect the resistance experienced by the transmission mechanism or the sliding cover.

[0107] Both the first and second sensors can be fixed by embedding or locking. Figure 10 This is a partially enlarged schematic diagram of the opening location of the projection device's housing, as shown below. Figure 10As shown, the identification unit 131a can be fixed by screw fastening; or, the identification unit 131b can be fixed by slot embedding. Similarly, the sensing unit 132a can be fixed by screw fastening; or, the sensing unit 132a can be fixed by slot embedding. For example, the sensing unit 132a can be fixed vertically with screws, or the sensing unit 132b can be fixed horizontally by slot embedding.

[0108] When the projection device is powered on, the controller opens the sliding cover, allowing internal components to protrude from the opening for projection. When the projection device is powered off, the controller closes the sliding cover. If the cover cannot close completely, light leakage can occur. Using a first sensor can prevent this problem. Meanwhile, if the sliding cover is subjected to external force by the user or an obstacle, the transmission mechanism or the cover itself can easily be damaged. Therefore, a second sensor is installed on the transmission mechanism or the cover to prevent damage.

[0109] The sliding cover closing process is as follows Figure 11 As shown, it includes the following steps:

[0110] S301, Control the sliding cover to close;

[0111] S302, The first sensor detects the displacement of the sliding cover;

[0112] S303. Determine the current position of the sliding cover based on the displacement;

[0113] S304. Compare the current position of the slider with the target position; if the current position of the slider is inconsistent with the target position, execute S305; if the current position of the slider is consistent with the target position, execute S307.

[0114] S305. Calculate the displacement that the sliding cover needs to move;

[0115] S306. Control the sliding cover to move according to the calculated displacement; and return to S302;

[0116] S307, Control the sliding cover to stop moving;

[0117] S308, The second sensor detects the resistance encountered by the sliding cover;

[0118] S309. Determine whether the resistance experienced by the sliding cover exceeds a preset threshold; if it does not exceed the preset threshold, execute S310; if it exceeds the preset threshold, execute S312.

[0119] S310. Determine the moving speed of the sliding cover based on the resistance it experiences and the relationship between resistance and speed.

[0120] S311. Control the sliding cover to move according to the determined moving speed, and return to S308;

[0121] S312, Control the sliding cover to stop moving and issue an alarm.

[0122] The first and second sensors operate simultaneously when the sliding cover moves, and can send detection data to the controller in real time. The controller compares the current position of the sliding cover with the target position in real time or periodically, thereby continuously modifying the data driving the sliding cover to move until the sliding cover reaches the target position. At the same time, the controller can also detect whether the sliding cover is subjected to external forces in real time or periodically, and adjust the sliding cover's moving speed according to the external forces. When the external forces are large, the sliding cover's moving speed is reduced; when the external forces are small, the sliding cover's moving speed is increased; when the external forces are too large, exceeding a preset threshold, the sliding cover needs to be stopped and an alarm needs to be issued. Once the external forces are removed, the sliding cover can be controlled to continue moving. Two closed-loop control circuits can be formed between the first sensor, the second sensor, the transmission mechanism, and the controller, which improves the control accuracy of the sliding cover and prevents damage to the sliding cover or the transmission mechanism.

[0123] In some embodiments, such as Figure 9 As shown, the projection device also includes a lens 113, which is located inside the housing 111. At this time, the transmission mechanism is connected to the lens 113 to drive the lens to extend or retract from the opening.

[0124] The identification unit 131 of the first sensor can be disposed on the housing 111, and the sensing unit 132 can be disposed on the lens 113 or the transmission mechanism.

[0125] Typically, the lens is located inside the housing and moves primarily within the housing. Therefore, when designing the lens's motion trajectory, there are no other structures obstructing the lens. Thus, in this application scenario, only the first sensor needs to be set up.

[0126] When the projection device is powered on, the lens 113 can be controlled to protrude from the opening in the housing 111, and the lens 113 needs to be moved to a fixed position to ensure clear imaging. Therefore, the relative position of the sensing unit 132 with respect to the recognition unit 131 can be detected in real time while the lens is moving, thereby controlling the movement of the lens 113 more precisely.

[0127] In some embodiments, such as Figure 12 As shown, the projection device 11 and the screen 22 can be separate structures. The projection device 11 can be mounted on the pan-tilt unit 33, and the transmission mechanism is connected to the pan-tilt unit 33 to move the pan-tilt unit 33 to a fixed position relative to the screen 22.

[0128] The identification unit 131 of the first sensor can be set on or near the screen 22, and the sensing unit 132 is set on the gimbal 33 or the projection device 11. The second sensor (not shown in the figure) is installed on the transmission mechanism or the gimbal 33 to detect the resistance experienced by the transmission mechanism or the gimbal.

[0129] When the projection device 11 and screen 22 adopt a separate structure, the projection device 11 needs to be moved to a fixed position relative to the screen 22 to ensure the clarity of the projection during projection. Therefore, when the projection device is turned on, the controller can control the pan-tilt unit to move, detect the position of the pan-tilt unit during movement, and control its movement to improve the accuracy of the pan-tilt unit's movement. At the same time, if the pan-tilt unit is subjected to external force, it can easily cause damage to the transmission mechanism. Therefore, a second sensor is installed on the transmission mechanism or the pan-tilt unit to adjust the pan-tilt unit's movement speed according to the magnitude of the external force, and to issue an alarm in time when the pan-tilt unit encounters significant resistance to prevent damage.

[0130] In some embodiments, such as Figure 13 As shown, the screen 22 can be rolled up and stored after the projection system is turned off. The top of the screen 22 can be connected to a hinge, which is connected to a transmission mechanism. The transmission mechanism can drive the screen to roll up or unfold. For this application scenario, the rolling up or unfolding of the screen 22 does not require very precise control, but if it is subjected to external force, it may be damaged. Therefore, only the second sensor 15 can be set and installed on the transmission mechanism or the hinge of the screen.

[0131] When the control screen is retracted or unfolded, the resistance encountered by the screen's hinge or transmission mechanism is detected in real time, and the rotation speed of the transmission mechanism is adjusted according to the resistance encountered to avoid damage to the transmission mechanism or hinge.

[0132] The above application scenarios are for illustrative purposes only. In practical applications, the first sensor and / or the second sensor can also be set at other locations in the projection system as needed. Both the first sensor and the second sensor can form a closed-loop control with the transmission mechanism and the controller, thereby improving the detection accuracy and avoiding damage to the transmission mechanism.

[0133] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0134] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A projection system, characterized in that, include: Projection equipment; A transmission mechanism is installed on the projection device; the transmission mechanism drives at least a portion of the structure of the projection device to move. A first sensor is mounted on the projection device; the first sensor detects displacements generated by at least a portion of the structure of the projection device. A controller, located inside the projection device and connected to the first sensor, drives the transmission mechanism based on the detected displacement to move at least a portion of the projection device to the target position.

2. The projection system as described in claim 1, characterized in that, The projection system also includes: The second sensor detects the resistance experienced by the transmission mechanism. The controller adjusts the transmission speed of the transmission mechanism based on the detected resistance.

3. The projection system as described in claim 2, characterized in that, The projection device includes a housing with an opening and a sliding cover at the opening. The transmission mechanism is connected to the sliding cover to drive the sliding cover to slide at the opening. The first sensor includes: an identification unit and a sensing unit; the identification unit and the sensing unit are respectively disposed on the edge of the opening and on the sliding cover; the sensing unit is connected to the controller; The second sensor is mounted on the transmission mechanism or the sliding cover.

4. The projection system as described in claim 3, characterized in that, The controller controls the sliding cover to close; The first sensor detects the displacement of the sliding cover; The second sensor detects the resistance experienced by the sliding cover; The controller determines the current position of the sliding cover based on the displacement of the sliding cover, compares the current position of the sliding cover with the target position, and when the current position of the sliding cover is inconsistent with the target position, calculates the displacement that the sliding cover needs to move, and controls the sliding cover to move according to the calculated displacement until the sliding cover moves to the target position. The controller adjusts the sliding cover's moving speed based on the resistance it experiences and a pre-stored correspondence between resistance and speed; when the resistance experienced by the sliding cover exceeds a preset threshold, the controller stops the sliding cover from moving and issues an alarm.

5. The projection system as described in claim 1, characterized in that, The projection device includes a housing and a lens, the housing having an opening and the lens located inside the housing; The transmission mechanism is connected to the lens to drive the lens to extend out or retract from the opening; The first sensor includes an identification unit and a sensing unit; the identification unit is disposed on the housing, the sensing unit is disposed on the lens or the transmission mechanism, and the sensing unit is connected to the controller.

6. The projection system as described in claim 2, characterized in that, The projection system further includes: a screen; the projection device is mounted on a pan-tilt unit, and the transmission mechanism is connected to the pan-tilt unit to move the pan-tilt unit to a fixed position relative to the screen; The first sensor includes: an identification unit and a sensing unit; the identification unit is disposed on the screen or near the screen; the sensing unit is disposed on the gimbal and is connected to the controller; The second sensor is mounted on the transmission mechanism or the pan-tilt unit.

7. The projection system as described in claim 2, characterized in that, The projection system further includes: a screen; the transmission mechanism is connected to the screen to drive the screen to retract or unfold; The second sensor is mounted on the transmission mechanism or the screen.

8. The projection system as described in any one of claims 3 to 7, characterized in that, The first sensor and the second sensor are fixed by embedding or locking.

9. The projection system as described in any one of claims 3 to 7, characterized in that, The first sensor is a displacement sensor; the second sensor is a pressure sensor.

10. The projection system as claimed in claim 9, characterized in that, The projection system also includes: Signal conversion circuit, connected to the sensor; An operational amplifier circuit is connected to the signal conversion circuit. A filter output circuit is connected to the operational amplifier circuit. The filter output circuit is connected to the controller.

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