Projection device

Abstract

An embodiment of the present application discloses a projection device, belonging to the field of projection technology. The projection device includes: an optical engine for emitting a light beam; and a projection screen including a base, a control mechanism, a screen sheet, and a guide roller; the control mechanism is fixed on the base, the screen sheet is fixedly connected to the control mechanism, the control mechanism can be tightened to unfold the screen sheet, or curled to retract the screen sheet, the screen sheet is used for reflecting the light beam emitted by the optical engine to display an image; the guide roller is arranged on the base and can be pressed against the screen sheet and can rotate around its own axis along the length direction. In the embodiment of the present application, since the guide roller can be pressed against the screen sheet and limit the pitch angle of the screen sheet, the guide roller can limit the screen sheet to the correct position, thereby avoiding problems such as distortion, blurring and distortion of the image displayed on the screen sheet, and thus improving the display effect of the projection screen.

Description

[0001] This embodiment of the present application claims the priority of the Chinese patent application with the application number 202010340787.1 and the invention title "Projection Device" filed on April 26, 2020, the entire content of which is incorporated herein by reference. This application is a divisional application of the domestic application with the application number 202010647717.0, the application date of July 7, 2020, and the invention title "Projection Device". Technical Field

[0002] This embodiment of the present application relates to the field of projection technology, and particularly relates to a projection device. Background Art

[0003] With the continuous development of technology, projection devices are increasingly applied in people's work and life. Currently, projection devices mainly include an optical engine and a projection screen. Among them, the light exit side of the optical engine faces the projection screen to emit a light beam to the projection screen, and the projection screen is used to receive the light beam and display an image.

[0004] In the related art, as Figure 1 shown, the projection screen 1 includes a screen sheet 11, a curling assembly 12, a lifting assembly 13, and a base 14. The curling assembly 12 is fixed on the base 14, the screen sheet 11 is fixedly connected to the curling assembly 12, and at the same time, the screen sheet 11 is also fixedly connected to one end of the lifting assembly 13 away from the curling assembly 12. The lifting assembly 13 and the curling assembly 12 can control the unfolding and curling of the screen sheet 11. Among them, the lifting assembly 13 includes multiple sets of brackets, and each set of brackets includes a first support rod 131 and a second support rod 132. At the three movable joints between the first end of the first support rod 131 and the base 14, between the second end of the first support rod 131 and the first end of the second support rod 132, and between the second end of the second support rod 132 and the screen sheet 11, all are rotatably connected, and multiple sets of brackets can control the unfolding of the screen sheet 11.

[0005] However, since assembly gaps are reserved at all three movable joints, when the lifting assembly 13 is lifted to unfold the screen sheet 11, under the reverse acting force of the screen sheet 11, the lifting assembly 13 is likely to tilt due to the assembly gaps reserved at the three movable joints. In addition, wear is likely to occur at all three movable joints, thus further aggravating the tilting degree of the lifting assembly 13. In this way, after the lifting assembly tilts, the screen sheet 11 will also tilt, resulting in problems such as distortion, blurring, and distortion of the image displayed on the screen sheet 11, thereby affecting the display effect of the projection screen 1. Summary of the Invention

[0006] This embodiment of the present application provides a projection device and a projection screen, which can solve the problem that the screen sheet included in the projection device is prone to tilting. The technical solution is as follows:

[0007] A projection device, the projection device comprising:

[0008] An optical engine for emitting a light beam;

[0009] A projection screen, the projection screen comprising a base, a control mechanism, a screen sheet and guide rollers;

[0010] The control mechanism is fixed on the base, the screen sheet is fixedly connected to the control mechanism, the control mechanism can be tightened to unfold the screen sheet, or curled to retract the screen sheet, and the screen sheet is used for reflecting the light beam emitted by the optical engine to display an image;

[0011] The guide rollers are arranged on the base and can be pressed against the screen sheet to define the pitch angle of the screen sheet.

[0012] Optionally, the base has two first guide grooves with opposite positions, and both ends of the guide roller are respectively located in the two first guide grooves and can move in the first guide grooves.

[0013] Optionally, the length direction of the first guide groove is the horizontal direction.

[0014] Optionally, the control mechanism includes a curling component and a lifting component;

[0015] The curling component is fixed on the base, the first side edge of the screen sheet is fixedly connected to the curling component, and the curling component can control the screen sheet to be curled on the curling component;

[0016] The first end of the lifting component is fixedly connected to the base, the second end of the lifting component is fixedly connected to the second side edge of the screen sheet opposite to the first side edge, and the lifting component can control the screen sheet to be unfolded.

[0017] Optionally, in the horizontal direction, when the intersection line between the screen sheet and the curling component is located between the first end and the second end of the lifting component, the guide roller presses the screen sheet on the side close to the lifting component.

[0018] Optionally, in the horizontal direction, when the intersection line between the screen sheet and the curling component is located on the side close to the second end of the lifting component, the guide roller presses the screen sheet on the side away from the lifting component.

[0019] Optionally, the guide roller includes two guide rollers with a gap design, both ends of the two guide rollers are fixedly connected, and the screen sheet passes through the gap between the two guide rollers.

[0020] Optionally, a protective coating is provided on the guide roller.

[0021] Optionally, the guide roller is in a strip-shaped structure, and the length direction of the guide roller is parallel to the axial direction of the curling assembly.

[0022] Optionally, the projection screen further comprises a control component, wherein the control component is drivingly connected to the guide roller, and the control component is used to receive a control instruction to drive the guide roller to move in the first guide groove.

[0023] Optionally, the projection device further comprises a storage portion, wherein the storage portion is used to store the optical engine and the projection screen;

[0024] The storage portion has a light-transmitting area and an opening, the light beam emitted by the optical engine can pass through the light-transmitting area, and the control mechanism can control the screen piece to pass through the opening and unfold.

[0025] The beneficial effects of the technical solution provided by the embodiments of the present application may at least include:

[0026] When the projection device is not in use, the screen is rolled up by the control mechanism to reduce the space occupied by the projection screen. When the projection device is in use, the screen is stretched out by the control mechanism so that the screen reflects the light beam emitted by the optical engine and displays the image. When the screen is in the unfolded state, since the guide roller is pressed against the screen and limits the pitch angle of the screen, the screen can be limited to the correct position by the guide roller, thereby avoiding the distortion, blurring and distortion of the image displayed on the screen, thereby improving the display effect of the projection screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a partially enlarged structural schematic diagram of a projection screen provided by the related art;

[0029] Figure 2 It is a side view structural schematic diagram of a projection screen provided by the related art;

[0030] Figure 3 It is a side view structural schematic diagram of another projection screen provided by the related art;

[0031] Figure 4 is a structural schematic diagram of a projection device provided in an embodiment of the present application;

[0032] Figure 5 It is a schematic structural diagram of a transmission mechanism provided by an embodiment of the present application;

[0033] Figure 6 It is a schematic structural diagram of another transmission mechanism provided by an embodiment of the present application;

[0034] Figure 7 It is a schematic structural diagram of yet another transmission mechanism provided by an embodiment of the present application;

[0035] Figure 8 It is an exploded structural diagram of yet another transmission mechanism provided by an embodiment of the present application;

[0036] Figure 9 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0037] Figure 10 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0038] Figure 11 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0039] Figure 12 It is an exploded structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0040] Figure 13 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0041] Figure 14 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0042] Figure 15 It is a schematic structural diagram of still another transmission mechanism provided by an embodiment of the present application;

[0043] Figure 16 It is a schematic side view structure diagram of a projection screen provided by an embodiment of the present application;

[0044] Figure 17 It is a schematic side view structure diagram of a projection screen provided by an embodiment of the present application;

[0045] Figure 18 It is a schematic side view structure diagram of another projection screen provided by an embodiment of the present application;

[0046] Figure 19 It is a schematic structural diagram of another projection device provided by an embodiment of the present application.

[0047] Reference numerals:

[0048] Related technologies:

[0049] 1: Projection screen; 11: Screen sheet; 12: Coiling assembly; 13: Lifting assembly; 14: Base

[0050] 131: First support rod; 132: Second support rod; 133: Connecting shaft

[0051] Embodiments of the present application:

[0052] 1: Optical engine; 2: Projection screen; 3: Storage part

[0053] 21: Base; 22: Control mechanism; 23: Screen sheet; 24: Guide roller; 25: Transmission mechanism; 26: Driving motor; 27: Adjusting knob; 31: Translucent area; 32: Opening

[0054] 211: First guide groove; 221: Coiling assembly; 222: Lifting assembly; 251: Worm; 252: Worm gear; 253: First gear; 254: Second gear; 255: Lead screw; 256: Third gear; 257: Rack; 258: Nut; 259: Bushing

[0055] 2510: Guide shaft; 2511: Fourth gear; 2512: Fifth gear; 2221: Cross beam; 2222: First support rod; 2223: Second support rod Detailed implementation manners

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will explain the situations such as the screen sheet being skewed or distorted in combination with related technologies.

[0057] In related technologies, for multiple groups of brackets included in the lifting assembly 13, as Figure 1 shown, each group of brackets further includes a connecting shaft 133; a first connecting groove is provided at the second end of the first support rod 131, the first end of the second support rod 132 extends into the first connecting groove, and the second end of the first support rod 131 and the first end of the second support rod 132 are rotatably connected through the connecting shaft 133. Among them, connecting holes are provided on the two groove walls of the first connecting groove and the side wall of the first end of the second support rod 132, and the connecting shaft 133 passes through the connecting holes on the two groove walls and the connecting hole on the second support rod 132 to achieve the rotatable connection between the first support rod 131 and the second support rod 132.

[0058] Generally, there is an assembly gap between the hole wall of the connection hole on the groove wall and the connection shaft 133. Exemplarily, the gap between the hole wall of the connection hole on the groove wall and the connection shaft 133 is less than or equal to 0.2 mm. In this way, the second support rod 132 is prone to tilt under the action of an external force, resulting in a change in the relative positional relationship between the second end of the first support rod 131 and the first end of the second support rod 132, and at the same time causing an angle between the straight line passing through the centers of the two connection holes on the first connection groove and the axial direction of the connection shaft 133. Further, after the second support rod 132 tilts, it will cause the screen 11 to also tilt forward or backward.

[0059] Wherein, the tilting angle of the second support rod 132 is equal to the angle between the straight line passing through the centers of the two connection holes on the first connection groove and the axial direction of the connection shaft 133. The maximum angle between the straight line passing through the centers of the two connection holes on the first connection groove and the axial direction of the connection shaft 133 is calculated according to the following formula:

[0060] α = tan -1 D / B

[0061] Wherein, α is the maximum angle between the straight line passing through the centers of the two connection holes on the first connection groove and the axial direction of the connection shaft 133, D is the gap between the hole wall of the connection hole and the connection shaft 133, and B is the distance between the two groove walls of the first connection groove.

[0062] It should be noted that since the position of the curling assembly 12 is fixed, the position of the side of the screen 11 connected to the curling assembly 12 will not change. And as Figure 2 shown, the second support rods 132 included in multiple groups of brackets may all tilt away from the screen 11. In this way, the side of the screen 11 connected to the multiple groups of brackets will tilt backward, resulting in the screen 11 tilting backward; as Figure 3 shown, the second support rods 132 included in multiple groups of brackets may also all tilt towards the screen 11. In this way, the side of the screen 11 connected to the multiple groups of brackets will tilt forward, resulting in the screen 11 tilting forward.

[0063] It should also be noted that the contact parts between the first support rod 131 and the connection shaft 133, between the first support rod 131 and the second support rod 132, and between the second support rod 132 and the connection shaft 133 are all prone to wear, thus further aggravating the degree of forward or backward tilt of the screen 11.

[0064] Based on the above description, in the related art, the screen 11 included in the projection screen 1 is very likely to tilt forward or backward, resulting in the screen 11 being unable to normally receive the light beam emitted by the optical engine, and thus causing problems such as distortion, blurring, and distortion in the displayed image.

[0065] Next, the embodiments of the present application will be further described in detail with reference to the accompanying drawings.

[0066] Figure 4 The structural schematic diagram of a projection device according to an embodiment of the present application is exemplified. As Figure 4 shown, the projection device includes: an optical engine 1 and a projection screen 2. The optical engine 1 is used to emit a light beam; the projection screen 2 includes a base 21, a control mechanism 22, a screen 23, and a guide roller 24; the control mechanism 22 is fixed on the base 21, the screen 23 is fixedly connected to the control mechanism 22, the control mechanism 22 can be tightened to unfold the screen 23, or curled to retract the screen 23. The screen 23 is used to reflect the light beam emitted by the optical engine 1 to display an image; the guide roller 24 is arranged on the base 21 and can be pressed against the screen 23 to limit the pitch angle of the screen 23.

[0067] In the embodiment of the present application, when the projection device is not in use, the control mechanism 22 curls to retract the screen 23, thereby reducing the space occupied by the projection screen 2. When the projection device is in use, the control mechanism 22 is tightened to unfold the screen 23, so that the screen 23 can reflect the light beam emitted by the optical engine 1 and display an image. When the screen 23 is in the unfolded state, since the guide roller 24 is pressed against the screen 23 and limits the pitch angle of the screen 23, the screen 23 can be limited to the correct position by the guide roller 24, and thus problems such as distortion and blurring of the image displayed on the screen 23 can be avoided, thereby improving the display effect of the projection screen 2.

[0068] In some embodiments, the base 21 is fixedly connected to the installation surface to fix the projection screen 2. The installation surface is the support surface of a fixed bracket or the wall surface of a wall, etc., as long as the fixed support of the projection screen 2 is achieved. The pitch angle of the screen 23 is the angle between the plane where the screen 23 is located and the vertical line.

[0069] Optionally, the optical engine 1 is an ultra-short-focus optical engine. In this way, the distance from the optical engine 1 to the plane where the projection screen 2 is located is set to a short distance to achieve the miniaturized design of the entire laser projection device. The optical engine 1 includes a light source, an optical machine system, and a lens. The optical machine system includes a DMD (Digital Micromirror Device) board and a DMD. The light source is used to emit a light beam to the optical machine system. The DMD board included in the optical machine system is used to provide a driving signal to the DMD, so that the DMD can modulate the light beam emitted by the light source based on the driving signal, and emit the modulated light beam to the lens, and then emit the light beam through the lens to the projection screen 2 for display.

[0070] Optionally, in the embodiments of the present application, the projection device is a laser ultra-short throw projection device, the ultra-short throw optical engine is a DLP (Digital Light Procession) projection optical engine, and the lens included in the optical engine 1 is an ultra-short throw projection lens. Also, the screen sheet 23 of the projection screen 2 is an optical screen sheet 23, such as a rollable Fresnel optical screen, or it can also be a flexible black grid screen. Such an optical screen sheet 23 has a higher optical gain compared to a traditional screen, can restore the brightness and contrast of the light beam as much as possible, and can achieve a higher flatness through the control and stretching of the control mechanism 22, and is applicable to ultra-short throw projection imaging applications.

[0071] In some embodiments, a protective coating is provided on the back surface of the screen sheet 23, that is, the side of the screen sheet 23 facing the control mechanism 22. In this way, the protective coating can prevent the back surface of the screen sheet 23 from directly contacting the front surface of the screen sheet 23 when the screen sheet 23 is in a curled state, thereby avoiding the mutual friction between the back surface and the front surface of the screen sheet 23 and causing wear of the screen sheet 23, and thus extending the service life of the screen sheet 23. Among them, the protective coating is a coating composed of flexible particles or a colloidal coating, and the embodiments of the present application do not limit this. The protective coating is made of nanomaterials, and the nanomaterials have good toughness, impact resistance, and thermal stability. Therefore, after the protective coating contacts the screen sheet 23, it can improve the flatness, wind resistance, and stability of the screen sheet 23, and can extend the life of the screen sheet 23.

[0072] In some embodiments, as Figure 4 shown, the guide roller 24 has a long strip-shaped structure, so as to be pressed tightly on the screen sheet 23 along the length direction to limit the screen sheet 23 in a large range. Of course, the guide roller 24 can also have other shaped structures, as long as it can press the screen sheet 23 and limit the pitch angle of the screen sheet 23.

[0073] Among them, the cross-sectional shape of the guide roller 24 is circular or polygonal, and the embodiments of the present application do not limit this. The guide roller 24 with a circular cross-sectional shape is easy to process, and the surface of the guide roller 24 is relatively smooth and not likely to cause damage to the screen sheet 23. The guide roller 24 with a polygonal cross-sectional shape has stronger stability and is not likely to shake. When the cross-section of the guide roller 24 is polygonal, for example, the cross-sectional shape is square or hexagonal.

[0074] It should be noted that when the guiding roller 24 is pressed against the curtain sheet 23, it can remain stationary or rotate around its own axis along the length direction. When the guiding roller 24 can rotate, when the control mechanism 22 curls to retract the curtain sheet 23 or tightens to unfold the curtain sheet 23, the guiding roller 24 rotates, so as to reduce the friction between the guiding roller 24 and the curtain sheet 23 and prevent damage to the curtain sheet 23 caused by friction between the guiding roller 24 and the curtain sheet 23. Of course, when the control mechanism 22 curls to retract the curtain sheet 23 or tightens to unfold the curtain sheet 23, in order to prevent friction, the guiding roller 24 can be moved away from the curtain sheet 23 to avoid direct contact between the guiding roller 24 and the curtain sheet 23.

[0075] In some embodiments, during the process of the control mechanism 22 tightening to unfold the curtain sheet 23, the guiding roller 24 is controlled to move away from the curtain sheet 23. When the curtain sheet 23 is unfolded on the control mechanism 22, the guiding roller 24 is controlled to press against the curtain sheet 23 to define the pitching angle of the curtain sheet 23. During the process of the control mechanism 22 curling to retract the curtain sheet 23, the guiding roller 24 that was originally pressed against the curtain sheet 23 can be moved away to avoid friction caused by direct contact between the guiding roller 24 and the curtain sheet 23. Further, when the projection screen 2 is used next time, the guiding roller 24 is kept in its original position. When the curtain sheet 23 is unfolded on the control mechanism 22 again, the guiding roller 24 is continuously controlled to press against the curtain sheet 23.

[0076] It should also be noted that in order to enable the guiding roller 24 pressed against the curtain sheet 23 to rotate around its own axis along the length direction, the guiding roller 24 is a drum-type guiding roller 24. The drum-type guiding roller 24 includes a central shaft and a drum. Both ends of the central shaft are connected to the base 21, and the drum is rotatably sleeved on the central shaft. In this way, the drum rotates around the central shaft. Of course, the guiding roller 24 can also be other types of guiding rollers 24, and the embodiments of the present application do not limit this. Among them, the drum is a hollow cylindrical drum or a hollow prismatic drum.

[0077] In some embodiments, a protective coating is provided on the guiding roller 24. In this way, the protective coating can avoid direct contact between the guiding roller 24 and the curtain sheet 23, so that when relative movement occurs between the curtain sheet 23 and the guiding roller 24, the surface of the guiding roller 24 can be prevented from scratching the curtain sheet 23 due to reasons such as unevenness, thereby prolonging the service life of the curtain sheet 23. Among them, the protective coating is a coating composed of flexible particles or a colloidal coating.

[0078] In some embodiments, such as Figure 5As shown in the figure, the base 21 has two first guiding grooves 211 which are opposite in position. Both ends of the guiding roller 24 are respectively located in the two first guiding grooves 211 and can move within the first guiding grooves 211. In this way, after the guiding roller 24 contacts the screen 23 and continues to move within the first guiding grooves 211, the screen 23 can be pushed. Since one side of the screen 23 away from the guiding roller 24 is fixed, when the guiding roller 24 pushes the screen 23, the pitching angle of the screen 23 can be changed. Further, when the guiding roller 24 changes the pitching angle of the screen 23 to the target pitching angle, the movement of the guiding roller 24 is controlled to stop and the guiding roller 24 is fixed so that the guiding roller 24 presses tightly on the screen 23, thereby realizing the limitation of the pitching angle of the screen 23.

[0079] Among them, the target pitching angle of the screen 23 is the included angle between the plane where the screen 23 is located and the vertical line when the screen 23 does not have unnecessary inclination. By way of example, the target pitching angle of the screen 23 is 0 degrees, 5 degrees, etc.

[0080] Among them, the base 21 includes two support plates, and the two first guiding grooves 211 are respectively arranged on the two support plates. In this way, it is convenient for both ends of the guiding roller 24 to pass through the two first guiding grooves 211 respectively.

[0081] Further, a fixing nut can be respectively arranged at both ends of the guiding roller 24, and after each fixing nut is tightened, it presses tightly on the support plate close to the end of the guiding roller 24. Of course, two fixing nuts can also be respectively arranged at each end of the guiding roller 24, and the two fixing nuts at each end press tightly on both sides of the support plate close to the end.

[0082] It should be noted that when the guiding roller 24 is the drum-type guiding roller 24 in the above embodiment, after controlling the guiding roller 24 to stop moving, both ends of the central shaft included in the guiding roller 24 are fixed in the first guiding groove 211. In this way, it does not affect the rotation of the hollow columnar drum around the central shaft.

[0083] Among them, the shape of the first guiding groove 211 is a long strip or an ellipse, or other shapes, as long as it can realize the movement of the guiding roller 24 within the first guiding groove 211 and be fixed on the first guiding groove 211. The embodiment of the present application does not make a limitation in this regard. The width of the first guiding groove 211 is slightly larger than the diameter or side length of the cross-section of the guiding roller 24. In this way, the guiding roller 24 can move more flexibly within the first guiding groove 211. The length of the first guiding groove 211 is set according to the limit inclination amount of the screen 23 along the length direction of the first guiding groove 211. The length of the first guiding groove 211 is slightly larger than the limit inclination amount of the screen 23 along the length direction of the first guiding groove 211 to avoid interference with the guiding roller 24 when the guiding roller 24 limits the pitching angle of the screen 23.

[0084] In some embodiments, the length direction of the first guide groove 211 is a horizontal direction or a direction forming an acute angle with the horizontal direction. Exemplarily, when the guide roller 24 moves within the first guide groove 211, there can be a moving component in the horizontal direction, so that the screen sheet 23 can be pressed or pushed in the horizontal direction, and further, the angle between the screen sheet 23 and the vertical direction can be adjusted or eliminated. Thus, when the guide roller 24 is pressed against the screen sheet 23, the pitching angle of the screen sheet 23 can be limited.

[0085] It should be noted that the target pitching angle of the screen sheet 23 is set according to the angle of the light beam emitted by the optical engine 1 or other factors. Further, the angle of the first guide groove 211 can be set according to the target pitching angle of the screen sheet 23, as long as the guide roller 24 moving within the first guide groove 211 can limit the pitching angle of the screen sheet 23 to the target pitching angle. The embodiments of the present application do not make any limitations in this regard.

[0086] In some embodiments, a lubricating member that closely fits the inner wall of the first guide groove 211 is provided on the inner wall of each first guide groove 211. In this way, the friction between the guide roller 24 and the first guide groove 211 can be reduced, the smoothness of the movement of the guide roller 24 within the first guide groove 211 can be enhanced, and at the same time, the movement accuracy of the guide roller 24 can be easily improved.

[0087] In some embodiments, the projection screen 2 further includes a control component, which is in transmission connection with the guide roller 24. The control component is used to receive a control instruction to drive the guide roller 24 to move within the first guide groove 211. In the embodiments of the present application, the control component can be an electric control component. In this way, the automatic control of the movement of the guide roller 24 can be realized, and the movement amount and movement accuracy of the guide roller 24 can be ensured. Further, the accurate limitation of the pitching angle of the screen sheet 23 can be ensured. Of course, the control component can also be a manual control component, so that the movement amount of the guide roller 24 can be adjusted manually, as long as it is convenient to adjust the guide roller 24.

[0088] In a first aspect, as Figure 5 shown, the control component is an electric control component, and the control component includes a transmission mechanism 25 and a driving motor 26. The transmission mechanism 25 is rotatably limited on the base 21, the driving motor 26 is fixed on the base 21, the output shaft of the driving motor 26 is connected to the transmission mechanism 25, and the transmission mechanism 25 is further connected to the guide roller 24. The driving motor 26 can drive the guide roller 24 to move within the first guide groove 211 through the transmission mechanism 25, so as to press against the screen sheet 23 and limit the pitching angle of the screen sheet 23.

[0089] It should be noted that the projection screen 2 further includes a control system, and the control system is electrically connected to the driving motor 26. When it is necessary to correct the position of the screen 23, the control system sends a start command to the driving motor 26 to control the driving motor 26 to start running. Then, the driving motor 26 drives the guide roller 24 to move through the transmission mechanism 25 to adjust the pitching angle of the screen 23. When the pitching angle of the screen 23 is adjusted to the target pitching angle, the control system sends a stop command to the driving motor 26 to control the driving motor 26 to stop running, and then the transmission mechanism 25 stops moving.

[0090] In the embodiment of the present application, the transmission mechanism 25 is a transmission mechanism 25 including a worm wheel 252 and a worm 251, or a transmission mechanism 25 including a lead screw 255. Of course, it can also be other transmission mechanisms 25, as long as it can drive the guide roller 24 to move in the first guide groove 211. When the transmission mechanism 25 is a transmission mechanism 25 including a worm wheel 252 and a worm 251, the axial direction of the output shaft of the driving motor 26 and the length direction of the worm 251 can be collinear, parallel, perpendicular, or the included angle between the two is an acute angle, etc. Any situation; when the transmission mechanism 25 is a transmission mechanism 25 including a lead screw 255, the axial direction of the output shaft of the driving motor 26 and the length direction of the lead screw 255 can also be collinear, parallel, perpendicular, or the included angle between the two is an acute angle, etc. Any situation.

[0091] Next, a detailed introduction to the transmission mechanism 25 including a worm wheel 252 and a worm 251 will be given.

[0092] In some embodiments, as Figure 5 shown, the transmission mechanism 25 includes a worm 251 and a worm wheel 252; the length direction of the worm 251 is parallel to the length direction of the first guide groove 211, and the worm 251 is rotatably limited on the base 21. The worm 251 is connected to the output shaft of the driving motor 26, and the driving motor 26 can drive the worm 251 to rotate along its circumferential direction; the worm wheel 252 is axially limited at the first end of the guide roller 24, and the worm 251 meshes with the worm wheel.

[0093] In this way, after the driving motor 26 is started, it can drive the worm 251 to rotate, and then drive the worm wheel 252 meshing with it to roll along the length direction of the worm 251. Since the worm wheel 252 is axially limited at the first end of the guide roller 24, the worm wheel 252 can drive the guide roller 24 to generate a displacement along the length direction of the worm 251 when rolling. Further, since the length direction of the worm 251 is parallel to the length direction of the first guide groove 211, it can be ensured that the guide roller 24 simultaneously generates a displacement along the length direction of the first guide groove 211.

[0094] Optionally, two limit sleeves are fixed on the base 21. The two limit sleeves are respectively sleeved on both sides of the spiral teeth of the worm 251, and can rotate relative to the worm 251. In this way, the two limit sleeves can support the worm 251 and ensure that the worm 251 rotates along its circumferential direction. For example, lubricating oil is provided at the contact part between the worm 251 and the limit sleeve to ensure the flexibility of the worm 251 during rotation.

[0095] Optionally, the worm gear 252 is fixedly connected to the first end of the guide roller 24. In this way, when the worm gear 252 rolls, it can drive the guide roller 24 to roll together, and at the same time, the fixed connection between the worm gear 252 and the guide roller 24 can achieve a smooth transmission of force. Of course, in some other embodiments, the worm gear 252 is rotatably limited at the first end of the guide roller 24. In this way, since the worm gear 252 and the guide roller 24 are rotatably connected, when the worm gear 252 rolls along the length direction of the worm 251, the guide roller 24 can be kept in a translational state.

[0096] Next, in the case where the transmission mechanism 25 includes the worm 251 and the worm gear 252, the relative position of the axial direction of the output shaft of the drive motor 26 and the length direction of the worm 251 will be introduced.

[0097] In some embodiments, the axial direction of the output shaft of the drive motor 26 is collinear with the length direction of the worm 251, and the output shaft of the drive motor 26 is fixedly connected to the end of the worm 251. In this way, after the drive motor 26 is started, when the output shaft rotates, it can drive the worm 251 fixedly connected thereto to rotate together.

[0098] Optionally, the output shaft of the drive motor 26 is fixedly connected to the end of the worm 251 through a coupling. Of course, it can also be fixedly connected by other means.

[0099] In some other embodiments, such as Figure 5As shown, the axial direction of the output shaft of the drive motor 26 is parallel to the length direction of the worm 251. Optionally, the transmission mechanism 25 further includes a first gear 253 and a second gear 254. The first gear 253 is fixedly connected to the output shaft of the drive motor 26 along the axial direction, and the second gear 254 is fixedly connected to one end of the worm 251 along the axial direction. The first gear 253 meshes with the second gear 254. Among them, in this embodiment, both the first gear 253 and the second gear 254 are cylindrical gears. In this way, after the drive motor 26 starts, it drives the first gear 253 to rotate. The first gear 253 drives the second gear 254 meshing with it to rotate, and then the second gear 254 drives the worm 251 to rotate together. Further, since both the first gear 253 and the second gear 254 are cylindrical gears, the axial direction of the first gear 253 is parallel to the axial direction of the second gear 254, so as to adapt to the situation where the axial direction of the output shaft of the drive motor 26 is parallel to the length direction of the worm 251.

[0100] Optionally, both the first gear 253 and the second gear 254 are straight-tooth cylindrical gears. Straight-tooth cylindrical gears have strong load-bearing capacity and are convenient for processing and production. In some embodiments, both the first gear 253 and the second gear 254 are helical cylindrical gears. In this way, the gear meshing performance is good, the operation is relatively stable, and a more constant transmission ratio can be ensured.

[0101] In still other embodiments, the axial direction of the output shaft of the drive motor 26 is perpendicular to the length direction of the worm 251. Correspondingly, the transmission mechanism 25 includes the first gear 253 and the second gear 254 in the above embodiments, where both the first gear 253 and the second gear 254 are bevel gears. In this way, the bevel gears can realize the transmission between two mutually perpendicular shafts.

[0102] Optionally, both the first gear 253 and the second gear 254 are straight-tooth bevel gears, and their advantages are the same as or similar to those of the above straight-tooth cylindrical gears. In some embodiments, both the first gear 253 and the second gear 254 are helical bevel gears, and their advantages are the same as or similar to those of the above helical cylindrical gears. This application embodiment will not be elaborated herein.

[0103] In still other embodiments, the axial direction of the output shaft of the drive motor 26 and the length direction of the worm 251 form an arbitrary acute angle. Correspondingly, the transmission mechanism 25 includes the first gear 253 and the second gear 254 in the above embodiments, where both the first gear 253 and the second gear 254 are bevel gears. In this way, the parameters of the bevel gears are selected according to the actual situation to adapt to the included angle between the axial direction of the output shaft of the drive motor 26 and the length direction of the worm 251.

[0104] It should be noted that, due to the different spatial environments in which the projection screen 2 is located, the fixed position of the drive motor 26 and the axial direction of the output shaft of the drive motor 26 will be adaptively adjusted according to the spatial environment in which the projection screen 2 is located. Accordingly, the positional relationship between the axial direction of the output shaft of the drive motor 26 and the length direction of the worm 251 will be adaptively changed, and then the types of the first gear 253 and the second gear 254 can be selected from any of the above-mentioned embodiments.

[0105] Next, the transmission mechanism 25 including the lead screw 255 will be described in detail.

[0106] In some embodiments, Figure 6 As shown, the transmission mechanism 25 includes a lead screw 255; the length direction of the lead screw 255 is parallel to the length direction of the first guide groove 211, and the lead screw 255 is rotatably limited on the base 21, and the lead screw 255 is threadedly connected to the first end of the guide roller 24; the output shaft of the drive motor 26 is connected to the lead screw 255, and the drive motor 26 can drive the lead screw 255 to rotate.

[0107] In this way, after the driving motor 26 is started, it can drive the lead screw 255 to rotate, and then the lead screw 255 drives the guide roller 24 threadedly connected thereto to move along the length direction of the lead screw 255 when rotating. Since the length direction of the lead screw 255 is parallel to the length direction of the first guide groove 211, it is possible to ensure that the guide roller 24 moves along the length direction of the first guide groove 211 at the same time, and further the guide roller 24 can be moved toward the curtain piece 23 and pressed against the curtain piece 23.

[0108] In some embodiments, the first end of the guide roller 24 has a threaded hole, and one end of the lead screw 255 passes through the threaded hole and is threadedly connected to the guide roller 24. In this way, the guide roller 24 can be threadedly connected to the lead screw 255 based on the threaded hole it has.

[0109] Optionally, the transmission mechanism 25 further includes a guide shaft, which is limited on the base 21, and the length direction of the guide shaft is parallel to the length direction of the lead screw 255. Accordingly, the guide roller 24 has a guide hole, the guide shaft passes through the guide hole, and the length of the guide shaft is greater than the length of the guide hole. In this way, when the guide roller 24 moves along the length direction of the lead screw 255, the guide shaft can play a guiding and limiting role, so as to improve the moving accuracy of the guide roller 24 and prevent the guide roller 24 from shaking unnecessarily.

[0110] In other embodiments, Figure 6As shown, the transmission mechanism 25 further includes a nut 258, which is limited at the first end of the guide roller 24, and one end of the lead screw 255 is threadedly connected to the nut 258. In this way, the guide roller 24 can be threadedly connected to the lead screw 255 through the nut 258. In addition, for lead screws 255 of different specifications, corresponding nuts 258 of different specifications can be replaced, so that the guide roller 24 can be used in conjunction with lead screws 255 of different specifications.

[0111] Alternatively, if Figure 7 As shown, the transmission mechanism 25 further includes a sleeve 259, which is sleeved on the first end of the guide roller 24, and the nut 258 is fixedly connected to the sleeve 259. In this way, the slider can be connected to the guide roller 24 based on the sleeve 259. The sleeve 259 is fixedly connected to the first end of the guide roller 24 to achieve smooth transmission of the force between the sleeve 259 and the guide roller 24. Of course, the sleeve 259 can also be rotatably connected to the first end of the guide roller 24, which is not limited in the embodiment of the present application.

[0112] Alternatively, if Figure 8 As shown, when the transmission mechanism 25 includes a guide shaft 2510, the side wall of the nut 258 has a protrusion, the protrusion has a guide hole, the guide shaft 2510 passes through the guide hole, and the length of the guide shaft 2510 is greater than the length of the guide hole. In this way, when the nut 258 moves along the length direction of the lead screw 255, the guide shaft 2510 can play a guiding and limiting role to improve the moving accuracy of the nut 258 and prevent the nut 258 from shaking unnecessarily.

[0113] Optionally, the transmission mechanism 25 further includes balls, the nut 258 has a circuit connected to the internal thread, the balls are arranged in the spiral space and the circuit formed by the nut 258 and the lead screw 255, and the balls can circulate and roll in the spiral space and the circuit when the nut 258 moves along the length direction of the lead screw 255. In this way, the balls can reduce the friction between the lead screw 255 and the nut 258, thereby enhancing the flexibility of the nut 258 when moving relative to the lead screw 255.

[0114] Next, in the case where the transmission mechanism 25 includes the lead screw 255 , the relative position of the axial direction of the output shaft of the drive motor 26 and the length direction of the lead screw 255 will be described.

[0115] In some embodiments, the axial direction of the output shaft of the drive motor 26 is colinear with the length direction of the lead screw 255, and the output shaft of the drive motor 26 is fixedly connected to the end of the lead screw 255. The connection mode between the drive motor 26 and the lead screw 255 is the same or similar to the connection mode between the drive motor 26 and the worm 251, and this embodiment of the application will not be described in detail.

[0116] In other embodiments,Figure 6 As shown, the axial direction of the output shaft of the drive motor 26 is parallel to the length direction of the lead screw 255. Optionally, the transmission mechanism 25 further includes a fourth gear 2511 and a fifth gear 2512. The fourth gear 2511 is fixedly connected to the output shaft of the drive motor 26 along the axial direction, and the fifth gear 2512 is fixedly connected to one end of the lead screw 255 along the axial direction. The fourth gear 2511 meshes with the fifth gear 2512. Among them, in this embodiment, both the fourth gear 2511 and the fifth gear 2512 are cylindrical gears. In this way, after the drive motor 26 is started, it drives the fourth gear 2511 to rotate. The fourth gear 2511 drives the fifth gear 2512 meshing with it to rotate, and then the fifth gear 2512 drives the lead screw 255 to rotate together. Further, since both the fourth gear 2511 and the fifth gear 2512 are cylindrical gears, the axial direction of the fourth gear 2511 is parallel to the axial direction of the fifth gear 2512, so as to adapt to the situation where the axial direction of the output shaft of the drive motor 26 is parallel to the length direction of the lead screw 255.

[0117] In some other embodiments, the axial direction of the output shaft of the drive motor 26 is perpendicular to the length direction of the lead screw 255. Correspondingly, the transmission mechanism 25 includes the fourth gear 2511 and the fifth gear 2512 in the above embodiment, where both the fourth gear 2511 and the fifth gear 2512 are bevel gears. In this way, the bevel gears can realize the transmission between two mutually perpendicular shafts.

[0118] In some other embodiments, the axial direction of the output shaft of the drive motor 26 and the length direction of the lead screw 255 form an arbitrary acute angle. Correspondingly, the transmission mechanism 25 includes the fourth gear 2511 and the fifth gear 2512 in the above embodiment, where both the fourth gear 2511 and the fifth gear 2512 are bevel gears. In this way, the parameters of the bevel gears are selected according to the actual situation to adapt to the included angle between the axial direction of the output shaft of the drive motor 26 and the length direction of the worm 251.

[0119] In the embodiments of the present application, in order to ensure the smoothness when the guide roller 24 moves, in some embodiments, a transmission mechanism 25 is also provided at the second end of the guide roller 24. When the transmission mechanism 25 includes a worm 251 and a worm wheel 252, the worm wheel 252 is axially limited at the second end of the guide roller 24. When the transmission mechanism 25 includes a lead screw 255, the lead screw 255 is threadedly connected to the second end of the guide roller 24. In this way, transmission mechanisms 25 are provided at both ends of the guide roller 24, and thus the two ends of the guide roller 24 can be controlled to move synchronously to ensure the smoothness of the overall movement of the guide roller 24. Correspondingly, the control system is connected to two drive motors 26 respectively located at both ends of the guide roller 24. The control system controls the two drive motors 26 to operate synchronously, and then the two drive motors 26 can drive the guide roller 24 to move based on both ends of the guide roller 24.

[0120] It should be noted that the moving directions of the corresponding ends on the guiding roller 24 controlled by the above two driving motors 26 can be the same or different, that is, one end of the guiding roller 24 moves towards the curtain sheet 23, and the other end of the guiding roller 24 moves away from the curtain sheet 23, or both ends of the guiding roller 24 move towards or away from the curtain sheet 23; in addition, the moving amounts of the corresponding ends on the guiding roller 24 controlled by the above two driving motors 26 can be the same or different. In this way, when the curtain sheet 23 swings left and right, the swinging directions on the left and right sides of the curtain sheet 23 are different, and the swinging amounts will also be different. Therefore, the starting times and forward and reverse rotations of the two driving motors 26 can be respectively controlled based on the different swinging amounts and swinging directions on the left and right sides of the curtain sheet 23, so that the two corresponding ends on the guiding roller 24 have different moving amounts and moving directions to adapt to the correction of the left and right swinging conditions of the curtain sheet 23 in practice.

[0121] In some other embodiments, as Figure 9 shown, the transmission mechanism 25 further includes a third gear 256 and a rack 257. The third gear 256 is axially limited at the second end of the guiding roller 24, the rack 257 is fixed on the base 21, the length direction of the rack 257 is parallel to the length direction of the first guiding groove 211, and is engaged with the third gear 256.

[0122] In this way, when the driving motor 26 drives the guiding roller 24 to roll based on the first end of the guiding roller 24 through the worm gear 252, the third gear 256 is fixedly connected to the second end of the guiding roller 24. Thus, the guiding roller 24 will drive the third gear 256 fixed to its second end to roll together, and further, the third gear 256 can roll along the length direction of the rack 257 engaged therewith. Since the length direction of the rack 257 is parallel to the length direction of the first guiding groove 211, it can be ensured that while the third gear 256 rolls along the length direction of the rack 257, a displacement amount along the length direction of the first guiding groove 211 is generated. Further, the third gear 256 can play a guiding role on the guiding roller 24, so that the second end of the guiding roller 24 generates a displacement amount along the length direction of the first guiding groove 211 synchronous with the first end.

[0123] When the driving motor 26 drives the guiding roller 24 to move based on the first end of the guiding roller 24 through the lead screw 255, the third gear 256 is rotatably sleeved on the second end of the guiding roller 24. Since the third gear 256 is also engaged with the rack 257, when the guiding roller 24 moves, it will drive the third gear 256 sleeved on its second end to generate a moving amount together. At the same time, the rack 257 causes the third gear 256 to roll along the length direction of the rack 257, and further, the third gear 256 can roll along the length direction of the rack 257 engaged therewith. Similarly, the third gear 256 can make the second end of the guiding roller 24 generate a displacement amount along the length direction of the first guiding groove 211 synchronous with the first end.

[0124] In a second aspect, as Figure 10 shown, the control component is a manual control component. The control component includes a transmission mechanism 25 and an adjustment knob 27. The transmission mechanism 25 and the adjustment knob 27 are rotatably limited on the base 21. The adjustment knob 27 is connected to the transmission mechanism 25. The transmission mechanism 25 is also connected to the guide roller 24. The adjustment knob 27 can drive the guide roller 24 to move in the first guide groove 211 through the transmission mechanism 25 to press against the screen sheet 23 and limit the pitching angle of the screen sheet 23.

[0125] In the embodiment of the present application, the structure of the transmission mechanism 25 is the same as or similar to that of the transmission mechanism 25 in the above first aspect. The connection manner between the adjustment knob 27 and the transmission mechanism 25 is the same as or similar to the connection manner and the relative position relationship between the output shaft of the driving motor 26 and the transmission mechanism 25 in the above first aspect. The embodiment of the present application will not elaborate on this, and specific reference can be made to Figures 11 to 15 the structure shown.

[0126] In some embodiments, as Figure 16 shown, the control mechanism 22 includes a curling component 221 and a lifting component 222; the curling component 221 is fixed on the base 21. The first side edge of the optical film sheet 23 is fixedly connected to the curling component 221. The curling component 221 can control the optical film sheet 23 to curl on the curling component 221; the first end of the lifting component 222 is fixedly connected to the base 21, and the second end of the lifting component 222 is fixedly connected to the second side edge of the optical film sheet 23 opposite to the first side edge. The lifting component 222 can control the optical film sheet 23 to unfold. In this way, when using the projection device, the lifting component 222 unfolds the optical film sheet 23 on the curling component 221. When the projection device stops being used, the curling component 221 can control the optical film sheet 23 to curl on the curling component 221, thereby reducing the space occupied by the projection screen 2.

[0127] In some embodiments, when the guide roller 24 is in a strip structure, the length direction of the guide roller 24 is parallel to the axial direction of the curling component 221. In this way, the flatness of the screen sheet 23 can be ensured, and the phenomenon that the screen sheet 23 is distorted due to the presence of the guide roller 24 can be avoided.

[0128] In some embodiments, as Figure 16As shown, in the horizontal direction, when the intersection line between the screen 23 and the curling assembly 221 is located between the first end and the second end of the lifting assembly 222, the guide roller 24 presses the screen 23 on the side of the screen 23 close to the lifting assembly 222. In this way, when the intersection line between the screen 23 and the curling assembly 221 is located between the first end and the second end of the lifting assembly 222, since the first side edge of the screen 23 is fixedly connected to the curling assembly 221 and the second side edge of the screen 23 is fixedly connected to the second end of the lifting assembly 222, the intersection line between the screen 23 and the curling assembly 221 is close to the first side edge of the screen 23. In this way, relative to the vertical direction, the screen 23 is inclined towards the lifting assembly 222. Further, the guide roller 24 located on the side of the screen 23 close to the lifting assembly 222 presses and pushes the screen 23, so that the screen 23 moves away from the lifting assembly 222, thereby enabling the correction of the pitching angle of the screen 23.

[0129] Wherein, the intersection line between the screen 23 and the curling assembly 221 is a line along the length direction of the curling assembly 221 formed at the position where the screen 23 curled on the curling assembly 221 is about to leave the curling assembly 221, that is, a line along the length direction of the curling assembly 221 at the tangent point between the unfolded part of the screen 23 and the curling assembly 221.

[0130] It should be noted that the lifting assembly 222 includes a cross beam 2221 and multiple groups of brackets. Each group of brackets includes a first support rod 2222 and a second support rod 2223. The first end of the first support rod 2222 is connected to the base 21, the second end of the first support rod 2222 is connected to the first end of the second support rod 2223, and the second end of the second support rod 2223 is connected to a side edge along the length direction of the cross beam 2221. At the same time, the other side edge along the length direction of the cross beam 2221 is fixedly connected to the second side edge of the screen 23, and the length of the cross beam 2221 is equal to the length of the second side edge of the screen 23. In this way, the cross beam 2221 can perform a full limit on the screen 23 along the length direction, thereby ensuring the flatness of the screen 23. In this embodiment, the second end of the lifting assembly 222 is specifically a side edge on the cross beam 2221 fixedly connected to the screen 23.

[0131] It should also be noted that, as Figure 17 shown, compared with Figure 5 , the included angle between the cross beam 2221 and the horizontal plane will change due to the pulling force of the screen 23, that is, the relative positions of the two side edges along the length direction on the cross beam 2221 in the vertical direction will change due to the pulling force of the screen 23. Therefore, the positional relationship among the intersection line between the screen 23 and the curling assembly 221, the first end and the second end of the lifting assembly 222 will change due to the change of the cross beam 2221. Therefore, the cross beam 2221 will affect the setting of the guide roller 24 to a certain extent.

[0132] In some other embodiments, as Figure 18 shown, in the horizontal direction, when the intersection line between the screen 23 and the curling assembly 221 is located on the side close to the second end of the lifting assembly 222, the guide roller 24 presses the screen 23 on the side of the screen 23 away from the lifting assembly 222. In this way, when the intersection line between the screen 23 and the curling assembly 221 is located on the side of the lifting assembly 222 close to the second end, since the first side of the screen 23 is fixedly connected to the curling assembly 221 and the second side of the screen 23 is fixedly connected to the second end of the lifting assembly 222, the intersection line between the screen 23 and the curling assembly 221 is close to the first side of the screen 23. In this way, relative to the vertical direction, the screen 23 is inclined in the direction away from the lifting assembly 222. Further, the guide roller 24 located on the side of the screen 23 away from the lifting assembly 222 presses and pushes the screen 23, so that the screen 23 approaches the lifting assembly 222, thereby realizing the correction of the pitching angle of the screen 23.

[0133] It should be noted that in the above two embodiments, the inclination of the lifting assembly 222 is the inclination of the second end of the lifting assembly 222 towards the direction where the screen 23 is located. When the inclination of the lifting assembly 222 is the inclination of the second end of the lifting assembly 222 towards the direction away from the direction where the screen 23 is located, the intersection line between the screen 23 and the curling assembly 221 is located on the side close to the first end of the lifting assembly 222. At this time, the guide roller 24 presses the screen 23 on the side of the screen 23 away from the lifting assembly 222.

[0134] It should also be noted that in the above two embodiments, the guide roller 24 corrects the pitching angle of the screen 23 in the area between the guide roller 24 and the second end of the lifting assembly 222. Therefore, the guide roller 24 is arranged at a position close to the curling assembly 221 to ensure the large-area adjustment of the screen 23.

[0135] In some embodiments, the guide roller 24 includes two guide rollers. The two guide rollers are designed with a gap, and the two ends of the two guide rollers are fixedly connected. The screen 23 passes through the gap between the two guide rollers. In this way, in the horizontal direction, whether the intersection line between the screen 23 and the curling assembly 221 is located between the first end and the second end of the lifting assembly 222, or the intersection line between the screen 23 and the curling assembly 221 is located on the side close to the second end of the lifting assembly 222, any one of the two guide rollers can press and push the screen 23, thereby realizing the correction of the pitching angle of the screen 23.

[0136] It should be noted that when the lifting assembly 222 rises to unfold the curtain piece 23, the curling assembly 221 can rotate clockwise or counterclockwise. When the central axis position of the curling assembly 221 remains fixed, the intersection line between the clockwise rotating curling assembly 221 and the curtain piece 23 and the counterclockwise rotating curling assembly 221 and the curtain piece 23 will be at different positions, and thus the relationship between the intersection line between the curtain piece 23 and the curling assembly 221, the first end of the lifting assembly 222, and the second end of the lifting assembly 222 will be different.

[0137] In some embodiments, the curtain 23 includes an optical film and a rollable substrate, the optical film is bonded to the rollable substrate, and a plurality of reinforcing ribs are provided on the side of the rollable substrate away from the optical film, and the length direction of each reinforcing rib is not parallel to the longitudinal direction of the rollable substrate; the rollable substrate is fixedly connected to the control mechanism 22, and the control mechanism 22 can be tightened to unfold the rollable substrate, or curled to fold the rollable substrate, and the rollable substrate supports the optical film in a flat state when it is unfolded; the optical film is used to reflect the light beam emitted by the optical engine 1 to display the picture.

[0138] In this way, the multiple reinforcing ribs can enhance the strength of the rollable substrate, while facilitating the rollability of the rollable substrate, and when the rollable substrate is in a flat state, the rollable substrate is subjected to uniform force in the lateral direction, and is not prone to ripples and wrinkles. Since the optical film is bonded to the rollable substrate, the optical film is not prone to wrinkles and deformation, thereby improving the display effect of the optical film.

[0139] In some embodiments, the screen piece 23 includes an optical film and a flexible carrier; the optical film is bonded to the flexible carrier, and two opposite sides of the flexible carrier are fixedly connected to the control mechanism 22, and the control mechanism 22 can be based on the two sides of the flexible carrier to tighten to unfold the flexible carrier, or curl up to fold the flexible carrier. When the flexible carrier is unfolded, the optical film is supported in a flat state.

[0140] In this way, while the control mechanism 22 indirectly tightens the optical film through the flexible carrier, the flexible carrier bears a part of the tensioning force of the control mechanism 22, so that the optical film is not easily damaged, thereby ensuring the flatness of the optical film.

[0141] The flexible carrier is a carrier such as synthetic cloth or film that is easy to curl and has load-bearing strength. When the flexible carrier is synthetic cloth, the material of the flexible carrier is a synthetic material containing nylon. Since nylon material has high mechanical strength, good toughness, and high tensile and compressive strength, the flexible carrier is not easily deformed when tightened by the control mechanism 22, and the surface is flat, thereby improving the flatness of the optical film. Of course, the material of the flexible carrier can also be other materials.

[0142] Among them, the optical film is bonded to the flexible carrier through a double-sided tape, a film adhesive, or other means, or by other bonding methods. The embodiments of the present application do not limit this.

[0143] In some embodiments, the screen sheet 23 includes an optical film, a rollable substrate, and a flexible carrier at the same time. The optical film is bonded to the rollable substrate, and one side of the rollable substrate away from the optical film is bonded to the flexible carrier. Both opposite side edges of the flexible carrier are fixedly connected to the control mechanism 22, and the control mechanism 22 can tighten the flexible carrier based on the two side edges of the flexible carrier to unfold the flexible carrier, or curl it up to retract the flexible carrier. When the flexible carrier is unfolded, it supports the rollable substrate to be in a flat state.

[0144] In some embodiments, when the control mechanism 22 includes a curling assembly 221, the curling assembly 221 includes a curling controller, a curling motor, and a reel. The curling controller is electrically connected to the curling motor. The curling motor is fixed on the base 21, and the output shaft of the curling motor is fixedly connected to the end of the reel. The first side edge of the screen sheet 23 is fixedly connected to the reel. Among them, the curling controller can control the start and stop of the curling motor, and the curling motor can drive the reel to rotate after starting. In this way, when the curling controller controls the reel to rotate, the screen sheet 23 can be controlled to curl on the reel.

[0145] When realizing the fixation of the screen sheet 23 and the reel, in some embodiments, a card slot is axially provided on the outer wall of the reel, and a card strip matching the card slot is provided on the first side edge of the screen sheet 23. The card strip can be radially limited in the card slot along the reel, so as to realize the circumferential limitation of the first side edge of the screen sheet 23 along the reel.

[0146] In this way, when the reel rotates, through the limitation of the card strip, the synchronous curling of the first side edge of the screen sheet 23 and the reel is realized, so that the screen sheet 23 is curled on the reel. And due to the limitation of the card strip, the reel provides a certain pulling force on the first side edge of the screen sheet 23, and this pulling force cooperates with the action when the second side edge of the screen sheet 23 is unfolded, making the screen sheet 23 flatter, thereby improving the display effect of the screen sheet 23.

[0147] In some embodiments, as Figure 19 shown, the projection device further includes a storage part 3. The storage part 3 is used to store the optical engine 1 and the projection screen 2; the storage part 3 has a light-transmitting area 31 and an opening 32. The light beam emitted by the optical engine 1 can pass through the light-transmitting area 31, and the control mechanism 22 can control the screen sheet 23 to pass through the opening 32 to unfold. In this way, when the projection device is not in use, the optical engine 1 and the projection screen 2 are stored in the storage part 3, which is convenient for saving space. When the projection device is in use, the control mechanism 22 controls the screen sheet 23 to unfold, and at the same time the optical engine 1 projects a light beam onto the screen sheet 23 so that the screen sheet 23 displays an image.

[0148] Among them, the vertical distance from the center point of the light-transmitting area 31 to the plane where the unfolded screen 23 is located is equal to the product of the projection ratio of the optical engine 1 and the width of the display area on the screen 23. The width of the display area refers to the size of the display area in the horizontal direction. In this way, it can be ensured that the light beam emitted by the optical engine 1 can be accurately projected onto the display area of the screen 23 to ensure the clarity of the displayed image on the screen 23.

[0149] Since the projection ratio is a performance parameter of the optical engine 1 itself, the projection ratio of the optical engine 1 is related to the selected optical engine 1. That is, if different optical engines 1 are selected, the projection ratio is different, and thus the vertical distance from the center point of the light-transmitting area 31 to the plane where the unfolded screen 23 is located is also different. In this way, during the actual setting process, the vertical distance from the center point of the light-transmitting area 31 to the plane where the unfolded screen 23 is located is calculated through the projection ratio of the optical engine 1 and the width of the display area, so as to ensure that the light beam emitted by the optical engine 1 can be completely projected onto the display area of the screen 23.

[0150] Optionally, the guide roller 24 is located in the storage part 3. In this way, the guide roller 24 can be hidden in the storage part 3, thereby enhancing the aesthetics of the projection screen 2, and can press the screen 23 before the screen 23 extends out of the storage part 3. In some other embodiments, the guide roller 24 is located above the storage part 3, and the guide roller 24 is arranged at a position that does not interfere with the display of the projection image on the screen 23. Generally, the guide roller 24 is arranged close to the storage part 3 and below the lower edge of the projection image.

[0151] It should be noted that when the projection screen 2 includes the screen 23 and the flexible carrier, the size of the screen 23 is smaller than that of the flexible carrier, and the edge of the screen 23 close to the storage part 3 is spaced a certain distance from the storage part 3. In this way, the guide roller 24 is located below the screen 23 and presses on the flexible carrier, thereby avoiding blocking the projection image.

[0152] Next, the structure of the projection screen including the tensioning mechanism will be explained in detail.

[0153] In some embodiments, the projection screen further includes a tensioning mechanism; the tensioning mechanism is fixedly connected to the curling assembly, and the curling assembly can control the tensioning mechanism to curl on the curling assembly; the second end of the lifting assembly is fixedly connected to the tensioning mechanism, and the lifting assembly can control the synchronous unfolding of the screen and the tensioning mechanism. When the tensioning mechanism unfolds, it can limit the pitching angle of the screen; wherein the lifting assembly is located between the screen and the tensioning mechanism.

[0154] In this way, when the screen and the tensioning mechanism are in the deployed state, since the lifting assembly is located between the screen and the tensioning mechanism, the tension of the tensioning mechanism on the lifting assembly is balanced with the tension of the screen on the lifting assembly. In this way, the tensioning mechanism can limit the pitching angle of the screen and correct the pitching angle of the screen at the same time.

[0155] In some embodiments, when the lifting assembly includes a cross beam, the cross beam is a thin plate-shaped cross beam. The screen is fixedly connected to the first side edge along the length direction of the cross beam, the tensioning mechanism is connected to the second side edge along the length direction of the cross beam, and the screen and the tensioning mechanism are respectively located on both sides of the second support rod. In this way, the tensioning mechanism balances the tension of the screen on the cross beam by tensioning the cross beam, thereby limiting the pitching angle of the screen.

[0156] In some embodiments, the curling assembly includes a first sub-curling assembly and a second sub-curling assembly; both the first sub-curling assembly and the second sub-curling assembly are connected to the base, the first sub-curling assembly and the screen are on the same side of the lifting assembly, and the second sub-curling assembly and the tensioning mechanism are on the same side of the lifting assembly; the screen is fixedly connected to the first sub-curling assembly, and the first sub-curling assembly can control the screen to curl on the first sub-curling assembly; the tensioning mechanism is fixedly connected to the second sub-curling assembly, and the second sub-curling assembly can control the tensioning mechanism to curl on the second sub-curling assembly.

[0157] In this way, since it is described in the above embodiments that the lifting assembly is located between the screen and the tensioning mechanism, the first sub-curling assembly and the screen are on one side of the lifting assembly, and the second sub-curling assembly and the tensioning mechanism are on the other side of the lifting assembly. Further, since the second sub-curling assembly can control the tensioning mechanism to curl on the second sub-curling assembly, after the screen tilts forward, the second sub-curling assembly is adjusted slightly forward to realize further curling of the tensioning mechanism, so that the tension of the tensioning mechanism on the second end of the lifting assembly can be increased to adjust the pitching angle of the screen. After the screen tilts backward, the second sub-curling assembly is adjusted slightly backward to realize slight deployment of the tensioning mechanism, so that the tension of the tensioning mechanism on the second end of the lifting assembly can be reduced to adjust the pitching angle of the screen. Similarly, after the screen tilts forward or backward, the pitching angle of the screen is adjusted by slightly adjusting the first sub-curling assembly, or the pitching angle of the screen is adjusted by slightly adjusting the first sub-curling assembly and the second sub-curling assembly at the same time.

[0158] It should be noted that the first sub-curling assembly independently controls the screen, and the second sub-curling assembly independently controls the tensioning mechanism, which is convenient for separately adjusting the tension of the screen on the second end of the lifting assembly and separately adjusting the tension of the tensioning mechanism on the second end of the lifting assembly.

[0159] In some embodiments, the tensioning mechanism includes an auxiliary roller and a tensioning assembly; the first end of the tensioning assembly is fixedly connected to the second end of the lifting assembly, the second end of the tensioning assembly is fixedly connected to the curling assembly, and both ends of the auxiliary roller are limited on the base and pressed against the tensioning assembly.

[0160] In this way, since the first end of the tensioning assembly is fixedly connected to the second end of the lifting assembly and the second end of the tensioning assembly is fixedly connected to the curling assembly, the curling assembly can curl to retract the tensioning assembly; the lifting assembly can lift to deploy the tensioning assembly. The curling assembly can simultaneously control the curtain sheet and the tensioning assembly to curl on the curling assembly, thereby facilitating the synchronous curling and deployment of the curtain sheet and the tensioning assembly. In addition, since the auxiliary roller is pressed against the tensioning assembly, the tensioning force of the tensioning assembly on the second end of the lifting assembly can be controlled.

[0161] In some embodiments, the tensioning assembly is a first auxiliary cloth or multiple first tensioning ropes. In the case where the lifting assembly includes a thin plate-shaped cross beam, when the tensioning assembly is the first auxiliary cloth, one side edge of the first auxiliary cloth is fixedly connected to the second side edge along the length direction of the cross beam, and the other side edge of the first auxiliary cloth opposite to one side edge is fixedly connected to the curling assembly. In this way, the first auxiliary cloth can tension the lifting assembly based on the cross beam. When the tensioning assembly is multiple first tensioning ropes, each pair of the first tensioning ropes is parallel to each other, and one end of each first tensioning rope can be fixedly connected to the second side edge along the length direction of the cross beam, and the other end of each first tensioning rope is fixedly connected to the curling assembly. In this way, the multiple first tensioning ropes can tension the lifting assembly based on the cross beam.

[0162] Among them, the first auxiliary cloth is fixedly connected to the cross beam by screws or by other means. In addition, the length of the side edge of the first auxiliary cloth fixedly connected to the cross beam and the length of the side edge of the curtain sheet fixedly connected to the cross beam are both less than or equal to the length of the cross beam. In this way, under the condition that the forces on both sides of the lifting assembly are more balanced, the cross beam can limit the first auxiliary cloth and the curtain sheet more comprehensively.

[0163] Among them, when the tensioning assembly is multiple first tensioning ropes, multiple fixing holes corresponding to the multiple first tensioning ropes can be provided on the cross beam, and each tensioning rope can be bundled and connected to the cross beam based on a corresponding fixing hole. The distance between each pair of the first tensioning ropes is equal. In this way, the tensioning force of each first tensioning rope on the cross beam is equal, thereby ensuring the stability of the cross beam and preventing it from skewing or the like.

[0164] It should be noted that when the lifting component includes a cross beam and the curling component includes a first sub-curling component and a second sub-curling component, the tensioning mechanism is a second auxiliary cloth or a plurality of second tension ropes. When the lifting component includes a thin plate-shaped cross beam and the tensioning mechanism is a second auxiliary cloth, the connection method and connection position of the second auxiliary cloth to the cross beam are the same as or similar to those of the first auxiliary cloth to the cross beam. The difference is that the second auxiliary cloth is fixedly connected to the second sub-curling component. When the tensioning mechanism is a plurality of second tension ropes, the connection method and connection position of the plurality of second tension ropes to the cross beam are the same as or similar to those of the plurality of first tension ropes to the cross beam. The difference is that the plurality of second tension ropes are fixedly connected to the second sub-curling component. This will not be elaborated in the embodiments of the present application.

[0165] In some embodiments, the auxiliary roller has a strip structure, and the length direction of the auxiliary roller is parallel to the axial direction of the curling component. In this way, the strip-shaped auxiliary roller is convenient to press against the tensioning component along the length direction to limit the tensioning component in a large range. Further, since the length direction of the auxiliary roller is parallel to the axial direction of the curling component, the auxiliary roller can ensure the flatness of the tensioning component, avoid the phenomenon that the tensioning component is distorted due to the existence of the auxiliary roller, and further avoid the distortion of the lifting component.

[0166] Among them, the cross-sectional shape of the auxiliary roller is circular or polygonal. The auxiliary roller with a circular cross-sectional shape is convenient for processing, and the surface of the auxiliary roller is relatively smooth and not easy to damage the screen.

[0167] It should be noted that when the auxiliary roller presses against the tensioning component, it is in a fixed state or can rotate around its own axis along the length direction. In the case where the auxiliary roller can rotate, when the curling component curls to retract the tensioning component, or the lifting component controls the tensioning component to unfold, the auxiliary roller rotates, so as to reduce the friction between the auxiliary roller and the tensioning component and prevent damage to the tensioning component caused by friction between the auxiliary roller and the tensioning component. Of course, when the curling component curls to retract the tensioning component, or tensions to unfold the tensioning component, in order to prevent friction, the auxiliary roller is moved away from the tensioning component to avoid direct contact between the auxiliary roller and the tensioning component. After the tensioning component is unfolded, the auxiliary roller presses against the tensioning component to limit the pitching angle of the screen.

[0168] In some embodiments, the auxiliary roller includes a central shaft and a drum. Both ends of the central shaft are connected to the base, and the drum is rotatably sleeved on the central shaft. In this way, the auxiliary roller is pressed against the side of the tensioning assembly close to the screen sheet. Among them, since the drum can rotate around the central shaft, when the curling assembly retracts or deploys the tensioning assembly, relative movement will occur between the tensioning assembly and the drum, which can significantly reduce the friction between the drum and the tensioning assembly, thereby avoiding wear on the tensioning assembly and improving the flexibility of the curling assembly to retract and deploy the tensioning assembly at the same time.

[0169] In some embodiments, a lubricating coating is provided on the auxiliary roller. In this way, the lubricating coating can avoid direct contact between the auxiliary roller and the tensioning assembly and can achieve a lubricating effect between the auxiliary roller and the tensioning assembly. Thus, the relative movement between the auxiliary roller and the tensioning assembly can be smoother, and at the same time, it can avoid scratching the tensioning assembly due to reasons such as the surface of the auxiliary roller not being smooth, thereby extending the service life of the tensioning assembly. Among them, the lubricating coating is a coating composed of flexible particles or a colloidal coating.

[0170] In some embodiments, two second guiding grooves are provided on the base at opposite positions. Both ends of the auxiliary roller are respectively located in the two second guiding grooves and can move in the second guiding grooves under the action of an external force to adjust the pressing force on the tensioning assembly. In this way, after the auxiliary roller contacts the tensioning assembly and continues to move in the second guiding groove, it can push the tensioning assembly. Since the first end of the tensioning assembly is fixedly connected to the second end of the lifting assembly, the second end of the tensioning assembly is fixedly connected to the curling assembly, and both the lifting assembly and the curling assembly are in a stationary state, when the auxiliary roller pushes the tensioning assembly, the pressing force on the tensioning assembly can be increased, thereby tightening the tensioning assembly. In this way, the tension force of the tensioning assembly on the second end of the lifting assembly will increase to a certain extent. Similarly, when the auxiliary roller moves away from the tensioning assembly along the length direction of the second guiding groove, the pressing force of the auxiliary roller on the tensioning assembly decreases, and the tension force of the tensioning assembly on the second end of the lifting assembly decreases.

[0171] It should be noted that the projection screen further includes a control assembly for controlling the movement of the auxiliary roller in the second guiding groove. The control assembly includes an auxiliary drive motor and an auxiliary transmission mechanism. Among them, the structure of the auxiliary transmission mechanism is the same as or similar to that of the transmission mechanism in the embodiments of the present application, and the embodiments of the present application will not elaborate on this.

[0172] Furthermore, the auxiliary roller can change the pitching angle of the screen sheet based on the adjustment of the pressing force on the tensioning assembly. When the pitching angle of the screen sheet is changed to the target pitching angle, the auxiliary roller is controlled to stop moving and the auxiliary roller is fixed, thereby realizing the limitation of the pitching angle of the screen sheet.

[0173] Among them, since the number of the second guiding grooves is two, correspondingly, the base includes two support plates, and the two second guiding grooves are respectively arranged on the two support plates. In this way, it is convenient for both ends of the auxiliary roller to pass through the two second guiding grooves respectively.

[0174] Among them, the shape of the second guiding groove is strip-shaped, oval-shaped, or other shapes, as long as it can enable the auxiliary roller to move in the second guiding groove and be fixed on the second guiding groove. The embodiments of the present application do not limit this. The width of the second guiding groove is slightly larger than the diameter or side length of the cross-section of the auxiliary roller. In this way, the auxiliary roller can move more flexibly in the second guiding groove.

[0175] In some embodiments, the length direction of the second guiding groove is the horizontal direction or a direction with an acute angle to the horizontal direction. Exemplarily, when the auxiliary roller moves in the second guiding groove, it can have a moving component in the horizontal direction. Therefore, the position where the tensioning assembly contacts the auxiliary roller, the first end of the tensioning assembly, and the relative position relationship of the second end of the tensioning assembly in the horizontal direction can be adjusted, so as to adjust the pressing force of the auxiliary roller on the tensioning assembly.

[0176] In some embodiments, lubricating members that are closely attached to the inner wall of the second guiding groove are arranged on the inner wall of each second guiding groove. In this way, the friction between the auxiliary roller and the second guiding groove can be reduced, the smoothness of the movement of the auxiliary roller in the second guiding groove can be enhanced, and at the same time, it is convenient to improve the movement accuracy of the auxiliary roller.

[0177] Next, the structure of the projection screen including the adjustment screw will be explained in detail.

[0178] In some embodiments, when the lifting assembly includes multiple groups of brackets, and each group of brackets includes a first support rod and a second support rod, the first end of the first support rod and the base, the second end of the first support rod and the first end of the second support rod, and the second end of the second support rod and the screen are all rotatably connected. The multiple groups of brackets can control the unfolding of the screen; an adjustment screw is arranged on one of the first support rod and the second support rod, and one end of the adjustment screw abuts against the side wall of the other, and the adjustment screw is used to adjust the relative position of the second end of the first support rod and the first end of the second support rod to adjust the pitching angle of the screen.

[0179] In this way, when the screen is in the unfolded state, since one end of the adjustment screw arranged on one of the first support rod and the second support rod abuts against the side wall of the other, the relative position of the second end of the first support rod and the first end of the second support rod is adjusted by rotating the adjustment screw. Furthermore, the inclination angle of the second support rod can be adjusted. Since the second end of the second support rod is connected to the screen, the pitching angle of the screen can be adjusted.

[0180] In some embodiments, the number of sets of brackets is set to two. In this way, one set of brackets is respectively arranged at positions near both ends of the curling component, so that the two sets of brackets can unfold the curtain based on the two ends of one side edge close to the curtain sheet. Of course, the number of sets of brackets can also be set to three. In this way, one set of brackets is respectively arranged at positions near both ends of the curling component, and one set of brackets is arranged at a position near the middle of the curling component. In this way, the three sets of brackets unfold the curtain based on the two ends of one side edge close to the curtain sheet and the central position of the side edge close to the curtain sheet.

[0181] It should be noted that assembly gaps are provided at the rotatable connection positions between the first end of the first support rod included in each set of brackets and the base, between the second end of the first support rod and the first end of the second support rod, and between the second end of the second support rod and the curtain sheet, so as to facilitate the flexible extension and folding of the brackets.

[0182] In some embodiments, each set of brackets includes a first connecting shaft. A first connecting groove is provided at the second end of the first support rod, and the first end of the second support rod extends into the first connecting groove. The second end of the first support rod and the first end of the second support rod are rotatably connected through the first connecting shaft. One end of the adjusting screw is screwed into the first connecting groove based on the outer wall of the first support rod and abuts against the outer wall of the second support rod. In this way, the cooperation between the first connecting groove and the first end of the second support rod facilitates the adjusting screw arranged on the first support rod to abut against the side wall of the second support rod.

[0183] Among them, the shape of the bottom surface of the first connecting groove is set according to the shape of the first support rod. By way of example, when the cross-sectional shape of the first support rod is square, the shape of the bottom surface of the first connecting groove is also square; when the cross-sectional shape of the first support rod is circular, the shape of the bottom surface of the first connecting groove is also circular.

[0184] Among them, a fixing nut is respectively arranged at both ends of the first connecting shaft, and each fixing nut is tightened and pressed against the side wall of the first support rod respectively. In this way, the first connecting shaft is fixedly connected to the first support rod. Further, when the second support rod rotates around the first connecting shaft, the angle change between the second support rod and the first support rod can be realized, so that the extension and folding of the bracket can be realized.

[0185] In some embodiments, the first support rod includes a rod body and two first connecting plates; the first end of the rod body is rotatably connected to the base, the two first connecting plates are relatively arranged at the end of the second end of the rod body to form a first connecting groove, and at least one of the first connecting plates is provided with at least one adjusting screw. In this way, since the first end of the second support rod extends into the first connecting groove formed by the two first connecting plates, and at least one of the first connecting plates is provided with at least one adjusting screw, the adjusting screw provided on the first connecting plate is rotated to make the adjusting screw push the second support rod, thereby realizing the adjustment of the relative position of the second support rod and the first support rod.

[0186] The two first connecting plates are arranged opposite to each other and are fixedly connected to the side wall of the rod body to form a first connecting groove with a larger space. The two first connecting plates are respectively welded to the rod body, or are respectively formed integrally with the rod body, which is not limited in the embodiment of the present application.

[0187] Wherein, an adjustment screw is arranged on any one of the two first connection plates, and the adjustment screw is not located at the same height as the first connection shaft. Thus, when the adjustment screw is rotated, the first connection shaft is used as a fulcrum to abut the second support rod and push the second support rod, thereby adjusting the inclination angle of the second support rod, so as to adjust the relative position of the first end of the second support rod and the second end of the first support rod.

[0188] Of course, in some embodiments, two adjustment screws are provided on any one of the first connecting plates, and the straight line formed by the two adjustment screws is along the vertical direction, or forms an acute angle with the vertical direction. In actual use, the two adjustment screws are usually used in combination. Specifically, one of the adjustment screws relatively located above is fixed and kept in contact with the side wall of the second support rod, and the other adjustment screw is rotated so that the adjustment screw pushes the second support rod, so that the second support rod is controlled to swing in a direction perpendicular to the line connecting the two adjustment screws, so that the inclination angle of the second support rod can be adjusted to achieve the adjustment of the relative position of the first end of the second support rod and the second end of the first support rod.

[0189] Of course, in some embodiments, three adjustment screws are provided on any one of the first connecting plates, and the three adjustment screws are connected to form an equilateral triangle. In this way, the three adjustment screws can constrain the second support rod at three locations, and the ends of the three adjustment screws can form a plane, thereby effectively preventing the second support rod from shaking randomly toward the plane where the ends of the three adjustment screws are located, thereby making the motion state of the second support rod more stable.

[0190] It should be noted that one, two or three adjusting screws can be provided on each first connecting plate. Since the first end of the second support rod extends into the first connecting groove formed by the two first connecting plates, the pushing directions of the adjusting screws on the two first connecting plates against the second support rod are opposite, so that the reciprocating adjustment of the inclination angle of the second support rod can be realized, and further the adjustment of the relative positions of the first end of the second support rod and the second end of the first support rod can be realized.

[0191] In some embodiments, an adjusting screw is provided on one of the first support rod and the base, and one end of the adjusting screw abuts against the side wall of the other. The adjusting screw is used to adjust the relative position between the first end of the first support rod and the base. In this way, the relative position between the first support rod and the base can be adjusted by rotating the adjusting screw.

[0192] In some embodiments, each set of brackets further includes a second connecting shaft; a second connecting groove is provided on the base, the first end of the first support rod extends into the second connecting groove, and the first end of the first support rod and the base are rotatably connected through the second connecting shaft; one end of the adjusting screw can be screwed into the second connecting groove based on the outer wall of the base and abut against the outer wall of the first support rod. In this way, the cooperation between the second connecting groove and the first end of the first support rod facilitates the adjusting screw provided at the second connecting groove of the base to abut against the side wall of the first support rod.

[0193] It should be noted that the structure of the second connecting groove is the same as or similar to that of the first connecting groove, and the setting manner of the adjusting screw on the second connecting groove can be the same as or similar to the setting manner of the adjusting screw on the first connecting groove, which will not be elaborated in the embodiments of the present application.

[0194] In some embodiments, when the lifting assembly includes a cross beam; an adjusting screw is provided on one of the second support rod and the cross beam, and one end of the adjusting screw abuts against the side wall of the other. The adjusting screw is used to adjust the relative position between the second end of the second support rod and the cross beam. In this way, the relative position between the second support rod and the cross beam can be adjusted by rotating the adjusting screw.

[0195] In some embodiments, each set of brackets further includes a third connecting shaft; a third connecting groove is provided on the cross beam, the second end of the second support rod extends into the third connecting groove, and the second end of the second support rod and the cross beam are rotatably connected through the third connecting shaft; one end of the adjusting screw is screwed into the third connecting groove based on the outer wall of the cross beam and abuts against the outer wall of the second support rod. In this way, the cooperation between the third connecting groove and the second end of the second support rod facilitates the adjusting screw provided at the third connecting groove of the cross beam to abut against the side wall of the second support rod.

[0196] It should be noted that the structure of the third connection groove is the same as or similar to that of the first connection groove. The setting method of the adjustment screw on the third connection groove can be the same as or similar to the setting method of the adjustment screw on the first connection groove, and this will not be elaborated in the embodiments of the present application.

[0197] In some embodiments, the projection screen further includes an adjustment shim; the adjustment shim is located in the first connection groove and is slidably sleeved on the first connection shaft. The adjustment shim is clamped between one end of the adjustment screw and the side wall of the second support rod. In this way, the adjustment screw directly abuts against the adjustment shim, so that the adjustment shim can disperse the thrust applied by the end of the adjustment screw, thereby enabling the force on the second support rod to be more uniform and avoiding stress concentration and uneven force caused by the direct contact between the adjustment screw and the side wall of the second support rod.

[0198] Among them, the adjustment shim has a circular thin sheet structure, or a square, triangular or other shaped structure. It should be noted that when the first support rod includes a first connection plate, in order to enable the adjustment screws provided at any position of the first connection plate to abut against the adjustment shim, the shape of the adjustment shim can be set to be similar to the shape of the first connection plate.

[0199] Among them, the thickness of the adjustment shim is much smaller than the gap width between the second end of the first support rod and the first end of the second support rod along the length direction of the first connection shaft, so as to facilitate the adjustment screw to freely adjust the positional relationship between the first support rod and the second support rod. For example, the thickness of the adjustment shim is one-sixth of the width of the gap.

[0200] In some embodiments, each group of brackets includes a second connection shaft. When a second connection groove is provided on the base, an adjustment shim is provided in the second connection groove, and the adjustment shim is slidably sleeved on the second connection shaft. The adjustment shim is clamped between one end of the adjustment screw screwed into the second connection groove and the side wall of the first support rod. In addition, the function and shape of the adjustment shim are the same as or similar to those of the adjustment shim in the above embodiments, and this will not be elaborated in the embodiments of the present application.

[0201] In some embodiments, each group of brackets includes a third connection shaft; when a third connection groove is provided on the cross beam, an adjustment shim is also provided in the third connection groove, and the adjustment shim is slidably sleeved on the third connection shaft. The adjustment shim is clamped between one end of the adjustment screw screwed into the third connection groove and the side wall of the second support rod. Similarly, the function and shape of the adjustment shim are the same as or similar to those of the adjustment shim in the above embodiments, and this will not be elaborated in the embodiments of the present application.

[0202] In the embodiments of the present application, when the projection device is not in use, the control mechanism is curled to retract the screen, thereby reducing the space occupied by the projection screen. When the projection device is in use, the control mechanism is tightened to unfold the screen, so that the screen can reflect the light beam emitted by the optical engine and display the picture. When the screen is in the unfolded state, since the guide roller presses on the screen and limits the pitching angle of the screen, the screen can be limited to the correct position through the guide roller, thereby avoiding problems such as distortion, blurring and distortion of the picture displayed on the screen, and improving the display effect of the projection screen. When the projection screen includes a rollable substrate, the rollable substrate has high support strength and uniform stress, so the screen adhered to the rollable substrate is not likely to wrinkle and deform. When the projection screen includes a flexible carrier, the flexible carrier can bear part of the tension force of the control mechanism, making the screen not easily damaged, thereby ensuring the flatness of the screen. In addition, the storage part can store the optical engine and the projection screen, thereby reducing the space occupancy when the projection device is not in use.

[0203] The foregoing is only an illustrative embodiment of the embodiments of the present application and is not intended to limit the embodiments of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A projection device, characterized in that, The projection device includes: An optical engine for emitting a light beam; A projection screen including a base, a control mechanism, a screen sheet, and guide rollers; The control mechanism is fixed on the base. The screen sheet is fixedly connected to the control mechanism. The control mechanism can be tightened to unfold the screen sheet or curled to retract the screen sheet. The screen sheet is used for reflecting the light beam emitted by the optical engine to display an image; The guide rollers are arranged on the base, press against the screen sheet, and can rotate around their own axes along the length direction; The base has two first guide grooves with opposite positions. The two ends of the guide roller are respectively located in the two first guide grooves and can move in the first guide grooves; The length direction of the first guide groove is the horizontal direction.

2. The projection device according to claim 1, characterized in that The projection device further includes a control component. The control component is in transmission connection with the guide roller, and the control component is an electric control component.

3. The projection device according to claim 2, characterized in that, The control component includes a transmission mechanism and a driving motor. The transmission mechanism is rotatably limited on the base. The driving motor is fixed on the base. The output shaft of the driving motor is connected to the transmission mechanism, and the transmission mechanism is connected to the guide roller.

4. The projection device according to claim 3, characterized in that, The transmission mechanism includes a lead screw. The lead screw is rotatably limited on the base. The lead screw is connected to the first end of the guide roller, and the driving motor drives the lead screw to rotate.

5. The projection device according to claim 4, characterized in that, The transmission mechanism includes a nut. The guide roller is threadedly connected to the lead screw through the nut.

6. The projection device according to any one of claims 1-5, characterized in that, The control mechanism includes a curling component and a lifting component; The curling component is fixed on the base. The first side edge of the screen sheet is fixedly connected to the curling component. The curling component can control the screen sheet to be curled on the curling component; The first end of the lifting component is fixedly connected to the base. The second end of the lifting component is fixedly connected to the second side edge of the screen sheet opposite to the first side edge. The lifting component can control the screen sheet to unfold.

7. The projection device according to claim 6, characterized in that, The guide roller includes two guide rollers with a gap design. The two ends of the two guide rollers are fixedly connected, and the screen sheet passes through the gap between the two guide rollers.

8. The projection device according to claim 6, wherein, A protective coating is provided on the guide roller.

9. The projection device according to claim 6, wherein The guide roller has a strip structure, and the length direction of the guide roller is parallel to the axial direction of the curling component.

10. The projection device according to claim 6, characterized in that, The projection device further includes a storage part for storing the optical engine and the projection screen; The storage part has a light-transmitting area and an opening. The light beam emitted by the optical engine can pass through the light-transmitting area, and the control mechanism can control the screen sheet to pass through the opening and unfold.

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