A rollable lift projection screen

Abstract

The application discloses a coiled lifting projection screen and belongs to the field of projection display. The coiled lifting projection screen comprises a projection curtain, a winding drum assembly and a plurality of reinforcing ribs. The projection curtain is provided with a transition area connected with a first edge, and the thickness of the reinforcing ribs in the transition area is positively correlated with the first distance in the direction perpendicular to the back surface of the projection curtain. In this way, when the projection curtain is coiled and wound on the winding drum assembly, the reinforcing ribs with gradually increasing thickness in the transition area can be used to support the projection curtain on the side of the reinforcing ribs in the transition area away from the winding drum assembly, so that the distance between the projection curtain and the winding drum assembly can gradually increase when the projection curtain is wound on the side of the transition area of the projection curtain away from the winding drum assembly, and the projection curtain can smoothly transition at the position of the first edge, thereby avoiding creases or wrinkles of the projection curtain after winding, and improving the flatness of the projection curtain.

Description

Technical Field

[0001] This application relates to the field of projection display, and in particular to a rollable and height-adjustable projection screen. Background Technology

[0002] With the continuous development of technology, laser projection systems are increasingly being used in people's work and daily lives. Currently, laser projection systems mainly consist of a laser projection device and a projection screen. The laser projection device emits a laser beam towards the projection screen, which receives the beam to display an image.

[0003] A projection screen typically includes a projection screen, a roll-up assembly, and a lifting mechanism. One side of the projection screen is connected to the roll-up assembly, and the other side is connected to the lifting mechanism. The roll-up assembly allows the screen to be retracted, and the lifting mechanism allows the screen to be extended.

[0004] However, because the projection screen has thickness, when the projection screen is rolled up, it is easily squeezed by the edge of the lower projection screen, resulting in creases or wrinkles, which leads to poor display effect. Summary of the Invention

[0005] This application provides a rollable and height-adjustable projection screen. The technical solution is as follows: According to one aspect of this application, a rollable and height-adjustable projection screen is provided, the rollable and height-adjustable projection screen comprising: Projection screen, roll assembly, and multiple reinforcing ribs; The first side of the projection screen is connected to the roll assembly; At least a portion of the projection screen is capable of being rolled up and wound around the roll assembly, and the front side of the projection screen is used to display the projected image. The plurality of reinforcing ribs are located on the back of the projection screen and are connected to the projection screen. The plurality of reinforcing ribs are arranged along the curling direction of the projection screen. The projection screen has a transition area connected to the first edge. The thickness of a plurality of reinforcing ribs located in the transition area in a direction perpendicular to the back of the projection screen is positively correlated with a first distance, which is the shortest distance between the reinforcing ribs and the first edge.

[0006] Optionally, the projection screen can be wound into multiple layers on the roll assembly; The transition zone is located in the first projection screen that is closest to the first edge among the multiple projection screens, and the ratio of the area of ​​the transition zone to the area of ​​the first projection screen is greater than two-fifths.

[0007] Optionally, among the plurality of reinforcing ribs, except for the reinforcing rib located in the transition zone, the other reinforcing ribs have the same thickness in the direction perpendicular to the back of the projection screen.

[0008] Optionally, the reinforcing rib includes a strip-shaped wrapping structure and a strip-shaped supporting structure; The length direction of the wrapping structure is parallel to the length direction of the support structure, and the wrapping structure wraps the support structure. The wrapping structure is fixedly connected to the back of the projection screen. The hardness of the supporting structure is greater than the hardness of the wrapping structure; Alternatively, the rigidity of the support structure is greater than the rigidity of the projection screen, and the rigidity of the projection screen is greater than the rigidity of the wrapping structure.

[0009] Optionally, the reinforcing rib includes a reinforcing rib body and a plurality of strip-shaped cores; The length direction of the reinforcing rib body is parallel to the length direction of the core body, and the plurality of core bodies are distributed inside the reinforcing rib body along a length direction perpendicular to the length direction of the reinforcing rib body; The hardness of the core is greater than the hardness of the reinforcing rib body; Alternatively, the hardness of the core is greater than the hardness of the projection screen, and the hardness of the projection screen is greater than the hardness of the reinforcing rib body.

[0010] Optionally, the reinforcing rib has a first end face and a second end face opposite each other along the length direction of the reinforcing rib, and a plurality of side faces connecting the first end face and the second end face, wherein the connection position of two adjacent side faces has a rounded corner structure.

[0011] Optionally, the first projection screen further includes a regular area, which is connected to the transition area in the first projection screen; In the multi-layered projection screen, all layers of the projection screen except the first layer also have transition zones and regular zones; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projection of the transition area in the other layers of the projection screen onto the roll assembly overlaps with the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly. The orthographic projection of the regular area in the other layers of the projection screen onto the roll assembly is offset from the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly. Circumferential distance between the first reinforcing rib and the second reinforcing rib d i ’ Satisfy the following formula: ; Wherein, the first reinforcing rib is the first i The last of a plurality of reinforcing ribs arranged along the curling direction of the projection screen, the second reinforcing rib being the first... i The first of a plurality of reinforcing ribs arranged along the curling direction of the projection screen on the +1 layer of projection screen. d i Let be the circumferential distance between two adjacent reinforcing ribs in the conventional area of ​​the i-th layer of the projection screen. h i The difference between the shortest distance between the second reinforcing rib and the shortest distance between the first reinforcing rib and the roll assembly. R i For the first i The radius of the regular area in the layered projection screen.

[0012] Optionally, all other projection screens in the multi-layer projection screen, except for the first projection screen, also have transition zones; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projection of the transition area in the other layers of the projection screen onto the roll assembly and the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly have an overlapping area. The thickness of the multiple reinforcing ribs in the transition area of ​​the other layers of the projection screen in the direction perpendicular to the back of the projection screen is positively correlated with the second distance, which is the shortest distance between the reinforcing rib and the second edge, which is the edge of the other layers of the projection screen close to the first edge when the projection screen is unfolded.

[0013] Optionally, the plurality of reinforcing ribs includes a plurality of target reinforcing ribs, the plurality of target reinforcing ribs being located in a plurality of transition zones in the multiple layers of the projection screen; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projections of two adjacent target reinforcing ribs on the roll assembly overlap. The thickness of the plurality of target reinforcing ribs in the direction perpendicular to the back of the projection screen is positively correlated with the third distance, which is the shortest distance between the target reinforcing ribs and the roll assembly.

[0014] Optionally, the rollable and height-adjustable projection screen further includes a connecting portion located between the projection screen and the reinforcing ribs, the connecting portion being fixedly connected to the back of the projection screen and the plurality of reinforcing ribs respectively; In a direction perpendicular to the back of the projection screen, the thickness of the connecting portion is less than the thickness of the projection screen and less than the thickness of the reinforcing rib.

[0015] The beneficial effects of the technical solutions provided in this application include at least the following: A rollable and height-adjustable projection screen is provided, comprising a projection screen, a roll-up assembly, and multiple reinforcing ribs. The projection screen has a transition zone connected to a first edge, and the thickness of the multiple reinforcing ribs in the transition zone, in a direction perpendicular to the back of the projection screen, is positively correlated with a first distance. Thus, when the projection screen is rolled up and wound onto the roll-up assembly, the multiple reinforcing ribs in the transition zone, with their gradually increasing thickness, can support the projection screen on the side of the transition zone away from the roll-up assembly. This allows the distance between the projection screen and the roll-up assembly to gradually increase as the screen is wound onto the transition zone away from the roll-up assembly, enabling a smooth transition at the first edge. This avoids creases or wrinkles caused by edge compression of the rolled-up projection screen, improving its flatness and solving the problem of poor display quality in related technologies, thereby enhancing the overall display effect of the projection screen. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a rollable, liftable projection screen in its retracted state. Figure 2 yes Figure 1 The diagram shows the structure of the rollable and liftable projection screen in its unfolded state. Figure 3 It is looking in a direction perpendicular to the front of the projection screen. Figure 2 The diagram shows the structure of the rollable and liftable projection screen. Figure 4 This is a schematic diagram of a rollable and height-adjustable projection screen in a stowed state, provided in an embodiment of this application. Figure 5 yes Figure 4 The diagram shows the structure of the rollable and liftable projection screen in its unfolded state. Figure 6 It is looking in a direction perpendicular to the front of the projection screen. Figure 4 The diagram shows the structure of the rollable and liftable projection screen. Figure 7 It is looking in a direction perpendicular to the back of the projection screen. Figure 4 The diagram shows the structure of the rollable and liftable projection screen. Figure 8 This is a schematic diagram of a rollable and liftable projection screen in related technologies; Figure 9 This is a schematic diagram of a reinforcing rib provided in an embodiment of this application; Figure 10 yes Figure 9 A schematic diagram of a cross-sectional structure showing the reinforcing ribs along the A1-A2 position; Figure 11 yes Figure 9 A schematic diagram of a cross-sectional structure showing the reinforcing ribs along the B1-B2 position; Figure 12 yes Figure 9 A schematic diagram of another cross-sectional structure of the reinforcing ribs along the A1-A2 position; Figure 13 yes Figure 9 A schematic diagram of another cross-sectional structure of the reinforcing rib along the B1-B2 position is shown; Figure 14 This is a schematic diagram of another rollable and liftable projection screen provided in an embodiment of this application; Figure 15 This is a schematic diagram of another rollable and liftable projection screen provided in an embodiment of this application; Figure 16 This is a schematic diagram of another rollable and liftable projection screen provided in an embodiment of this application; Figure 17 yes Figure 16 The diagram shows the structure of the first and second projection screens in the unfolded state of the rollable and liftable projection screen. Figure 18 This is a schematic diagram of another rollable and liftable projection screen provided in an embodiment of this application; Figure 19 This is a schematic diagram of the structure of a laser projection system provided in an embodiment of this application.

[0018] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of a rollable and height-adjustable projection screen 10 in its retracted state. Figure 2 Yes Figure 1 The diagram shown illustrates the structure of the rollable and retractable projection screen 10 in its unfolded state. Figure 3 It is looking in a direction perpendicular to the front of the projection screen 11. Figure 2 Please refer to the structural schematic diagram of the rollable and height-adjustable projection screen 10 shown below. Figure 1 , Figure 2 and Figure 3 A rollable and height-adjustable projection screen 10 is a device used to receive images projected by a projector. To improve the ease of use of the rollable and height-adjustable projection screen 10, a current rollable and height-adjustable projection screen 10 may include a projection screen 11 and a roll assembly 12, wherein when the projection screen 11 is retracted, the projection screen 11 can be rolled up on the roll assembly 12.

[0021] like Figure 1 As shown, the material of the projection screen 11 may include polyethylene terephthalate (PET). When the projection screen 11 is rolled onto the roll assembly 12, the projection screen 11 is wound into multiple layers on the roll assembly 12. Because the PET material is relatively hard and has a certain thickness, the edges of the projection screen 11 have thickness. When the second layer of the projection screen 11 is rolled up, a fulcrum will be formed at the contact point between the edge of the second layer of the projection screen 11 and the edge of the first layer of the projection screen 11, resulting in a suspended area on the side of the second layer of the projection screen 11 near the edge of the first layer of the projection screen 11. The shape and stress of the second layer of the projection screen 11 are different on both sides of the first layer of the projection screen 11. The edge of the first layer of the projection screen 11 will squeeze the second layer of the projection screen 11, causing the projection screen 11 and other layers of the projection screen 11 to deform.

[0022] This can result in irreversible creases and wrinkles on the projection screen 11, such as... Figure 2 and 3 As shown, after the projection screen 11 is unfolded, creases z1 and wrinkles will be left on the projection screen 11. Under conditions of drastic changes in temperature and humidity, the problems of creases z1 and wrinkles may be aggravated. This seriously affects the display effect of the rollable and height-adjustable projection screen 10, and may even cause the projection screen 11 to break, resulting in a shorter lifespan for the rollable and height-adjustable projection screen 10.

[0023] This application provides a rollable and height-adjustable projection screen, which can solve the problems existing in related technologies.

[0024] Figure 4 This is a schematic diagram of the structure of a rollable and height-adjustable projection screen 20 in a retracted state, according to an embodiment of this application. Figure 5 yes Figure 4 The diagram shown illustrates the structure of the rollable and retractable projection screen 20 in its unfolded state. Figure 6It is looking in a direction perpendicular to the front of the projection screen 21. Figure 4 The diagram shown illustrates the structure of the rollable and height-adjustable projection screen 20. Figure 7 It is looking along the direction perpendicular to the back of the projection screen 21. Figure 4 Please refer to the structural schematic diagram of the rollable and height-adjustable projection screen 20 shown below. Figure 4 , Figure 5 , Figure 6 and Figure 7 The rollable and height-adjustable projection screen 20 may include: a projection screen 21, a roll assembly 22, and multiple reinforcing ribs 23.

[0025] The first side b1 of the projection screen 21 can be connected to the roll assembly 22, at least a portion of the projection screen 21 can be rolled up and wound onto the roll assembly 22, and the front side of the projection screen 21 can be used to display the projected image.

[0026] Multiple reinforcing ribs 23 can be located on the back of the projection screen 21 and connected to it. These reinforcing ribs 23 can be arranged along the rolling direction f2 of the projection screen 21. When the projection screen 21 is unfolded, the multiple reinforcing ribs 23 are arranged on the back of the projection screen 21 in a direction f1 away from the roll assembly 22. When the projection screen 21 is in the retracted state, the front of the projection screen 21 can be in contact with the surface of the roll assembly 22.

[0027] The projection screen 21 may have a transition area q1 connected to the first side b1. The first transition area q1 may be located at the connection position between the projection screen 21 and the roll assembly 22. That is, when the projection screen 21 is rolled up on the roll assembly 22, the transition area q1 may be located at the starting position of the roll.

[0028] The thickness of the multiple reinforcing ribs 23 located in the transition zone q1 in the direction perpendicular to the back of the projection screen 21 is positively correlated with the first distance, which is the shortest distance between the reinforcing rib 23 and the first edge b1. As the distance between the reinforcing rib 23 and the first edge b1 gradually increases, the thickness of the reinforcing rib 23 in the direction perpendicular to the back of the projection screen 21 also gradually increases. Thus, during the retraction of the projection screen 21, when the projection screen 21 is wound to the side of the transition zone q1 away from the roll assembly 22, the multiple reinforcing ribs 23 with gradually increasing thickness in the transition zone q1 can support the projection screen 21 located on the side of the transition zone q1 away from the roll assembly 22. This allows the distance between the projection screen 21 and the roll assembly 22 to gradually increase as the projection screen 21 is wound to the side of the transition zone q1 away from the roll assembly 22, and allows for a smooth transition when the projection screen 21 is wound to the position of its first edge b1. This results in a more uniform force distribution on the projection screen 21 when it is wound to the side of the transition zone q1 away from the roll assembly 22. This avoids creases or wrinkles caused by the compression of the first edge b1 of the projection screen 21 after winding.

[0029] For example, such as Figure 1 and Figure 4 As shown, when the projection screen 21 can be wound into multiple layers on the roll assembly 22, in related technologies, the second layer projection screen 212 located at the edge of the first layer projection screen 211 contacts the edge of the first layer projection screen 211 and is squeezed by the edge of the first layer projection screen 211, resulting in the cross-sectional shape of the second layer projection screen 212 being a zigzag line. In this embodiment, the cross-sectional shape of the second layer projection screen 212 located at the edge of the first layer projection screen 211 (i.e., at the location of the first side b1 of the projection screen 21) and on the side of the transition zone q1 away from the roll assembly 22 can be a smooth curve, and the second layer projection screen 212 can avoid contact with the edge of the first layer projection screen 211. This results in better flatness of the projection screen 21 in this embodiment.

[0030] In addition, since the rollable and lifting projection screen 20 provided in this application embodiment is in the stored state, the other layers of projection screen 21 located on the first side b1 of the projection screen 21 that are away from the roll assembly 22 will not be affected by the first side b1, thereby reducing the risk of damage to the projection screen 21 and improving the lifespan of the rollable and lifting projection screen 20.

[0031] In summary, this application provides a rollable and height-adjustable projection screen including a projection screen, a roll-up assembly, and multiple reinforcing ribs. The projection screen has a transition area connected to a first edge, and the thickness of the multiple reinforcing ribs located in the transition area in the direction perpendicular to the back of the projection screen is positively correlated with a first distance. Thus, when the projection screen is rolled up and wound onto the roll-up assembly, the multiple reinforcing ribs in the transition area, with their gradually increasing thickness, can support the projection screen on the side of the transition area away from the roll-up assembly. This allows the distance between the projection screen and the roll-up assembly to gradually increase as the projection screen is wound onto the side of the transition area away from the roll-up assembly, and the projection screen can smoothly transition at the location of the first edge. This avoids creases or wrinkles caused by the edge of the projection screen being squeezed after winding, improving the flatness of the projection screen and solving the problem of poor display effect in related technologies for rollable and height-adjustable projection screens, thereby improving the display effect of the projection screen.

[0032] It should be noted that the rollable and height-adjustable projection screen 20 provided in this application embodiment can include an unfolded state and a retracted state. The unfolded state refers to the state where the projection screen 21 is not rolled up and wrapped around the roll assembly 22, and is unfolded outside the roll assembly 22. The retracted state refers to the state where the projection screen 21 is rolled up and wrapped around the roll assembly 22. Of course, the projection screen 21 can also be partially rolled up and wrapped around the roll assembly 22, and this application embodiment does not limit this. In the length direction of the roll assembly, the length of the reinforcing rib can be greater than or equal to the length of the projection screen, so that the reinforcing rib can play a role in supporting the projection screen, which can further improve the flatness of the projection screen.

[0033] Please refer to Figure 4 and Figure 7 In one optional embodiment, the projection screen 21 can be wound into multiple layers on the roll assembly 22. A transition zone q1 can be located in the first layer of the multi-layer projection screen 21 that is closest to the first edge b1, and the ratio of the area of ​​the transition zone q1 to the area of ​​the first layer of the projection screen 211 is greater than two-fifths. Thus, a transition zone q1 can be provided in a portion of the first layer of the projection screen 211 near the first edge b1, allowing the distance between the other layers of the roll-up projection screen 20 and the roll assembly 22 to gradually increase as the first layer of the roll-up projection screen 20 is wound to the side opposite to the roll assembly 22. This allows the other layers of the roll-up projection screen 20 to smoothly transition at the location of the first edge b1, preventing creases or wrinkles caused by pressure on the edges of the rolled projection screen 21, and improving the flatness of the projection screen 21.

[0034] For example, the number of reinforcing ribs 23 on the first projection screen 211 is 10, and the number of reinforcing ribs 23 in the transition area q1 of the first projection screen 211 can be 4.

[0035] Figure 8 This is a schematic diagram of a rollable and height-adjustable projection screen 10 in related technologies. Please refer to it. Figure 8 The rollable and height-adjustable projection screen 10 in the related technology includes a projection screen 11, multiple reinforcing ribs 13, and a roll assembly 12. One end of the projection screen 11 is connected to the roll assembly 12 to facilitate winding and storage within the roll assembly 12. The multiple reinforcing ribs 13 have the same thickness in the direction perpendicular to the back of the projection screen 11. Although the reinforcing ribs 13 of the same thickness can support the rollable and height-adjustable projection screen 10 to prevent the second layer of projection screen 11 from being squeezed by the first side of the projection screen 11, the projection screen 11 located on the side of the reinforcing ribs 13 away from the roll assembly 12 will be squeezed by the reinforcing ribs 13, resulting in new creases and wrinkles on the projection screen 11.

[0036] Therefore, in this embodiment of the application, by providing multiple reinforcing ribs 23 with gradually increasing thickness, the reinforcing ribs 23 can be prevented from squeezing and bending the roll-up projection screen 20. In an exemplary embodiment, the thickness of the multiple reinforcing ribs 23 in the direction perpendicular to the back of the projection screen 21 is greater than the thickness of the projection screen 21 in the direction perpendicular to the back of the projection screen 21.

[0037] like Figure 4 As shown, in one exemplary embodiment, among the multiple reinforcing ribs 23 in the rollable and height-adjustable projection screen 20, the thickness of the other multiple reinforcing ribs 23, excluding the reinforcing rib 23 located in the transition zone q1, can be the same in the direction perpendicular to the back surface of the projection screen 21. The thickness of these other multiple reinforcing ribs 23 can be greater than or equal to the thickness of the reinforcing rib 23 with the largest thickness among the multiple reinforcing ribs 23 located in the transition zone q1. In this way, the manufacturing difficulty of the projection screen 21 can be reduced.

[0038] When the projection screen 21 is wound into multiple layers on the roll assembly 22, at least two reinforcing ribs 23 located on different layers of adjacent projection screens 21 have overlapping orthographic projections on the roll assembly 22. For example, the first layer of the multi-layer projection screen 21 has a third reinforcing rib 233, and the second layer of the projection screen 212 has at least a fourth reinforcing rib 234. The orthographic projections of the third reinforcing rib 233 and the fourth reinforcing rib 234 on the first layer of the projection screen 211 have an overlapping area.

[0039] Thus, when the rollable and height-adjustable projection screen 20 is in its retracted state, the reinforcing ribs 23 of different layers can support each other when compressing the projection screen 21, avoiding the problem of the reinforcing ribs 23 on different layers of the projection screen 21 shearing the projection screen 21, reducing the risk of creases or wrinkles on the projection screen 21, and protecting the projection screen 21. In addition, since the reinforcing ribs 23 of different layers of the rollable and height-adjustable projection screen 20 provided in this embodiment can support each other when in its retracted state, the problem of the reinforcing ribs 23 on different layers of the projection screen 21 shearing the projection screen 21 will not occur, thereby also reducing the risk of damage to the projection screen 21 and improving the lifespan of the rollable and height-adjustable projection screen 20.

[0040] Figure 9 This is a schematic diagram of the structure of a reinforcing rib 23 provided in an embodiment of this application. Figure 10 yes Figure 9 The diagram shows a cross-sectional structure of the reinforcing rib 23 along the A1-A2 position. Figure 11 yes Figure 9 The diagram shown is a cross-sectional structural schematic of the reinforcing rib 23 along the B1-B2 position. Please refer to it. Figure 9 , Figure 10 and Figure 11 In one optional embodiment, the reinforcing rib 23 may include a strip-shaped wrapping structure 23a and a strip-shaped supporting structure 23b. The length direction of the wrapping structure 23a may be parallel to the length direction of the supporting structure 23b, and the wrapping structure 23a may wrap around the supporting structure 23b. The wrapping structure 23a may be fixedly connected to the back of the projection screen 21. The rigidity of the supporting structure 23b may be greater than that of the wrapping structure 23a.

[0041] The length of the wrapping structure 23a can be the same as the length of the supporting structure 23b, or the length of the wrapping structure 23a can be slightly greater than the length of the supporting structure 23b, so as to also wrap both ends of the supporting structure 23b. The support structure with higher rigidity can be used to increase the strength of the reinforcing rib 23, so that the reinforcing rib 23 can support the projection screen 21, thereby improving the flatness of the screen and thus improving the display effect of the rollable and height-adjustable projection screen 20. The wrapping structure 23a with lower rigidity can be located on the surface of the supporting structure 23b to prevent the higher rigidity support structure from directly contacting the projection screen 21 and damaging it. In other words, the supporting structure 23b can be used to implement the supporting function of the reinforcing rib 23, while the wrapping structure 23a serves to protect the projection screen 21.

[0042] For example, the material of the supporting structure 23b may include at least one of metal, composite carbon fiber material and glass fiber reinforced composite material, and the material of the wrapping structure 23a may include at least one of rubber and silicone rubber.

[0043] Alternatively, in one exemplary embodiment, the rigidity of the support structure 23b can be greater than the rigidity of the projection screen 21, and the rigidity of the projection screen 21 can be greater than the rigidity of the wrapping structure 23a. This further prevents the reinforcing rib 23 from damaging the rollable and height-adjustable projection screen 20.

[0044] Figure 12 yes Figure 9 The diagram shows another cross-sectional structure of the reinforcing rib 23 along the A1-A2 position. Figure 13 yes Figure 9 Please refer to the schematic diagram of another cross-sectional structure of the reinforcing rib 23 along the B1-B2 position. Figure 12 and Figure 13 Optionally, the reinforcing rib 23 may include a reinforcing rib body 23c and a plurality of strip-shaped cores 23d. The length direction of the reinforcing rib body 23c may be parallel to the length direction of the cores 23d, and the plurality of cores 23d may be distributed inside the reinforcing rib body 23c along a length direction perpendicular to the length direction of the reinforcing rib body 23c. The hardness of the cores 23d is greater than the hardness of the reinforcing rib body 23c. The plurality of cores 23d may be uniformly distributed inside the reinforcing rib body 23c.

[0045] The core 23d, which has higher rigidity, can be used to increase the strength of the reinforcing rib 23, so that the reinforcing rib 23 can support the projection screen 21, thereby improving the flatness of the screen and thus enhancing the display effect of the rollable and height-adjustable projection screen 20. The body 23c of the reinforcing rib 23, which has lower rigidity, can be located on the surface of the support structure 23b to prevent the core 23d, which has higher rigidity, from directly contacting the projection screen 21 and damaging it.

[0046] For example, the material of the core 23d may include at least one of metal, composite carbon fiber material and glass fiber reinforced composite material, and the material of the reinforcing rib 23 body 23c may include at least one of rubber and silicone rubber.

[0047] Alternatively, in one exemplary embodiment, the hardness of the core 23d is greater than the hardness of the projection screen 21, and the hardness of the projection screen 21 is greater than the hardness of the reinforcing rib 23 body 23c. This further prevents the reinforcing rib 23 from damaging the rollable and height-adjustable projection screen 20.

[0048] Please refer to Figure 12In one optional embodiment, the reinforcing rib 23 has a first end face and a second end face opposite each other along the length direction of the reinforcing rib 23, and a plurality of side faces 23e connecting the first end face and the second end face. The connection position of two adjacent side faces 23e has a rounded corner structure 23r. When the rollable and height-adjustable projection screen 20 is in the storage state, the reinforcing rib 23 and the projection screen 21 will be in a stacked state. By setting the connection position of the side faces 23e of the reinforcing rib 23 as a rounded corner structure 23r, stress concentration at the contact position between the reinforcing rib 23 and the projection screen 21 stacked on the reinforcing rib 23 can be avoided, and damage to the projection screen 21 by the right-angled edge of the reinforcing rib 23 can also be prevented.

[0049] In the rollable and liftable projection screen 20 provided in the above embodiments, the reinforcing ribs 23 can be set on the back of the projection screen 21 in a variety of ways. For example, the reinforcing ribs 23 can be bonded to the projection screen 21; or, the support component also includes multiple fixing structures located on the projection screen 21 (the fixing structures can be nets, hooks or buckles, etc.), and the reinforcing ribs 23 are located on the fixing structures; or, the rollable and liftable projection screen 20 also includes a covering layer, and multiple reinforcing ribs 23 are located between the covering layer and the projection screen 21. The covering layer can be attached to the area on the back of the projection screen 21 that is not covered by the reinforcing ribs 23, so as to fix the reinforcing ribs 23 to the back of the projection screen 21.

[0050] Figure 14 This is a schematic diagram of another rollable and height-adjustable projection screen 20 provided in this application embodiment. Please refer to it. Figure 14 In one exemplary embodiment, the rollable and height-adjustable projection screen 20 may further include a connecting portion 24 located between the projection screen 21 and the reinforcing ribs 23. The connecting portion 24 may be fixedly connected to the back surface of the projection screen 21 and the plurality of reinforcing ribs 23 respectively. In the direction perpendicular to the back surface of the projection screen 21, the thickness of the connecting portion 24 may be less than the thickness of the projection screen 21 and may be less than the thickness of the reinforcing ribs 23.

[0051] Thus, by providing a connecting part 24 between the projection screen 21 and the reinforcing ribs 23, multiple reinforcing ribs 23 can be fixed to the back of the projection screen 21. The projection screen 21 and the reinforcing ribs 23 can be manufactured separately and then assembled together by a connecting process, so that the organizational state and performance of the projection screen 21 and the reinforcing ribs 23 remain unchanged.

[0052] In addition, the thickness of the connecting part 24 is less than the thickness of the projection screen 21 and less than the thickness of the reinforcing rib 23. When the projection screen 21, the connecting part 24 and the reinforcing rib 23 are in a high-temperature environment, even if the connecting part 24 expands due to heat, the impact on the projection screen 21 is small, which can improve the flatness of the projection screen 21.

[0053] The connecting part 24 may include multiple connecting strips, each corresponding to a plurality of reinforcing ribs 23 located on the back of the projection screen 21. The orthographic projection of each connecting strip on the back of the projection screen 21 may lie within the orthographic projection of the corresponding reinforcing rib 23 on the back of the projection screen 21. In this case, by setting multiple connecting strips to connect one-to-one with multiple reinforcing ribs 23, the assembly flexibility of each reinforcing rib 23 to the back of the projection screen 21 is ensured, and the overall weight of the connecting part 24 is reduced, resulting in a smaller overall weight of the rollable and height-adjustable projection screen 20.

[0054] Figure 15 This is a schematic diagram of another rollable and height-adjustable projection screen 20 provided in this application embodiment. Please refer to it. Figure 15 , Figure 15 The structure of the projection screen 21 has been simplified to more clearly show its rolled shape. In an optional embodiment, the first projection screen 211 may further include a regular area q2, which is connected to the transition area q1 in the first projection screen 211. The plurality of reinforcing ribs 23 located in the regular area q2 have the same thickness in a direction perpendicular to the back surface of the projection screen 21.

[0055] Since the front of the first-layer projection screen 211 can be fitted with the roll-up assembly 22 when the roll-up projection screen 20 is in the retracted state, the multiple reinforcing ribs 23 on the back of the first-layer projection screen 211 will not affect the first-layer projection screen 211. Therefore, the circumferential spacing between any two adjacent reinforcing ribs 23 on the first-layer projection screen 211 can be equal.

[0056] In the multi-layer projection screen 21, all layers of projection screen 21 except the first layer 211 also have a transition area q1 and a regular area q2. When the projection screen 21 is wound into multiple layers on the roll assembly 22, the orthographic projection of the transition area q1 in the other layers of projection screen 21 onto the roll assembly 22 overlaps with the orthographic projection of the transition area q1 in the first layer 211 onto the roll assembly 22. The orthographic projection of the regular area q2 in the other layers of projection screen 21 onto the roll assembly 22 is offset from the orthographic projection of the transition area q1 in the first layer 211 onto the roll assembly 22. For other layers of projection screen 21, when they are wound onto the roll assembly 22, they are affected by the lower layer of projection screen 21 and the reinforcing ribs 23. Furthermore, since the transition zone q1 of the other layers of projection screen 21 is located on the side of the transition zone q1 of the first layer of projection screen 211 away from the roll assembly 22, the circumferential spacing between any two adjacent reinforcing ribs 23 in the transition zone q1 of the other layers of projection screen 21 will be affected by the multiple gradually increasing thickness reinforcing ribs 23 in the transition zone q1 of the first layer of projection screen 211, resulting in unequal circumferential spacing between any two adjacent reinforcing ribs 23 in the transition zone q1 of the other layers of projection screen 21. The circumferential spacing between any two adjacent reinforcing ribs 23 in the regular zone q2 of the other layers of projection screen 21 can be equal.

[0057] For example, the distance between two adjacent reinforcing ribs 23 in the regular area q2 of a multi-layer projection screen 21 can be calculated as follows, assuming the roll radius is R and the screen thickness is δ (not shown in the figure). The width of the reinforcing rib 23 in the direction parallel to the back surface of the projection screen 21 is w, the thickness is h in the direction perpendicular to the back surface of the projection screen 21, and the radius of the i-th ring is R. i The following formula (i≥1) can be satisfied:

[0058] The number of reinforcing ribs 23 on each layer of projection screen 21 is m, and the spacing between adjacent reinforcing ribs 23 in the regular area q2 of the i-th layer of projection screen 21 is d. i Let the width w and spacing d of the reinforcing ribs be 23d. i Each element can form a basic unit, which corresponds to a central angle θ0. The geometric relationship between the arc length and the central angle of a circle satisfies the following formula:

[0059] Thus, after setting the number m of reinforcing ribs 23, the width w of the reinforcing ribs 23, and the thickness of the reinforcing ribs 23 on each layer of projection screen 21 as known parameters, the spacing d between two adjacent reinforcing ribs 23 in the conventional area q2 of the multi-layer projection screen 21 can be calculated according to the above formula. iIt should be noted that the basic unit size is the same in the regular area q2 of the same projection screen 21, but the basic unit size is different in the regular area q2 of different projection screens 21 because the radii are different.

[0060] Figure 16 This is a schematic diagram of another rollable and height-adjustable projection screen 20 provided in an embodiment of this application. Figure 17 yes Figure 16 The diagram shown illustrates the structure of the first projection screen 211 and the second projection screen 212 in the unfolded state of the rollable and liftable projection screen 20. Please refer to [the diagram]. Figure 16 and Figure 17 , Figure 16 The structure of the projection screen 21 has been simplified to more clearly illustrate its rolled shape. The distance between two adjacent reinforcing ribs 23 in the transition zone q1 of the multi-layer projection screen 21, and the distance between the first reinforcing rib 231 and the second reinforcing rib 232, can be calculated as follows: the first reinforcing rib 231 is the last reinforcing rib 23 among the multiple reinforcing ribs 23 arranged along the rolling direction f2 of the i-th layer of the projection screen 21; the second reinforcing rib 232 is the first reinforcing rib 23 among the multiple reinforcing ribs 23 arranged along the rolling direction f2 of the (i+1)-th layer of the projection screen 21. The rolling direction f2 refers to the direction from the i-th layer of the multi-layer projection screen 21 towards the (i+1)-th layer.

[0061] For example, the cross-sectional shape of the projection screen 21 between the first reinforcing rib 231 and the second reinforcing rib 232 can be an Archimedean spiral, so that the projection screen 21 can smoothly transition when wound to the side of the transition zone q1 away from the roll assembly 22. The Archimedean spiral equation is expressed in polar coordinates as r = α + βθ. Where (r, θ) are the polar radius r and polar angle θ, α and β are unknown undetermined coefficients, and O is the pole.

[0062] like Figure 16 and 17 As shown, assuming the coordinate of the starting point P of the distance between the first reinforcing rib 231 and the second reinforcing rib 232 is (R... i ,0), the endpoint Q coordinate is (R i +h i Substituting the Archimedes' spiral equation into the coordinates of points P and Q and solving the system of equations, we can obtain α = R. i β = R i h i / d i Therefore, the Archimedes spiral equation can be expressed as the following formula:

[0063] By calculating the circumferential distance between the first reinforcing rib 231 and the second reinforcing rib 232 using the integral formula of the arc length of the curve in polar coordinates, the circumferential distance between the first reinforcing rib 231 and the second reinforcing rib 232 can be obtained. d i ’ Satisfy the following formula:

[0064] in, d i For the first i The circumferential distance between two adjacent reinforcing ribs 23 in the regular area q2 of the layered projection screen 21. h i The difference between the shortest distance between the second reinforcing rib 232 and the drum assembly 22 and the shortest distance between the first reinforcing rib 231 and the drum assembly 22. R i For the first i The radius of the regular area q2 in the layered projection screen 21.

[0065] For example, the distance between the first reinforcing rib 231 on the first projection screen 211 and the second reinforcing rib 232 on the second projection screen 212 can be calculated as follows, wherein the radius of the roll assembly 22 is 45mm, the width of the reinforcing rib 23 is 5mm, and the thickness of the reinforcing rib 23 in the regular area q2 is 2.5mm (this thickness may include the thickness of the connecting strip). The thicknesses of the four reinforcing ribs 23 in the transition area q1 on the first projection screen 211 can gradually increase in an arithmetic progression. For example, the tolerance of the arithmetic progression can be 0.7, and the thicknesses of the four reinforcing ribs 23 can be 0.5mm, 1.2mm, 1.9mm, and 2.6mm, respectively. Alternatively, the tolerance of the arithmetic progression can be 0.8, and the thicknesses of the four reinforcing ribs 23 can be 0.5mm, 1.3mm, 2.1mm, and 2.9mm, respectively.

[0066] Thus, the difference between the shortest distance between the second reinforcing rib 232 and the shortest distance between the first reinforcing rib 231 and the roll assembly 22 is 0.5 mm, and the number of reinforcing ribs 23 on each layer of projection screen 21 is 10. Based on the above, it can be calculated that the distance between two adjacent reinforcing ribs 23 on the first layer of projection screen 211 can be 23.6 mm, and the distance between the first reinforcing rib 231 and the second reinforcing rib 232 can be 23.7 mm.

[0067] In one exemplary implementation, please refer to Figure 16 and Figure 17The roll-up shape of the projection screen 21 between the first reinforcing rib 231 on the first layer of projection screen 211 and the fifth reinforcing rib 235 on the second layer of projection screen 212 can also be an Archimedean spiral, so that the projection screen 21 can smoothly transition when it is rolled up to the side of the transition zone q1 away from the roll assembly 22. The fifth reinforcing rib 235 refers to a reinforcing rib 23 located on the side of the second reinforcing rib 232 away from the first reinforcing rib 231 and adjacent to the second reinforcing rib 232. At this time, di can be the circumferential distance between the two reinforcing ribs 23 that are furthest apart among the three reinforcing ribs 23 arranged sequentially in the regular area q2 of the i-th layer of projection screen 21.

[0068] Similarly, the distance between the reinforcing ribs 23 in the transition zone q1 of the multi-layer projection screen 21, as well as the distance between the first reinforcing rib 231 and the second reinforcing rib 232, can be calculated according to the calculation method in the above embodiments, and will not be elaborated further in this application embodiment. In this way, the spacing between multiple reinforcing ribs 23 on the projection screen 21 can be reasonably designed according to the size, number and other parameters of the reinforcing ribs 23, so that the upper and lower layers of the projection screen 21 overlap after being rolled up, and the transition zone q1 of the projection screen 21 can smoothly transition during the rolling process, avoiding indentations on the projection screen 21.

[0069] Please refer to Figure 16 Optionally, the circumferential spacing between two adjacent reinforcing ribs 23 on the i-th layer of projection screen 21 can be smaller than the circumferential spacing between two adjacent reinforcing ribs 23 on the (i+1)-th layer of projection screen 21. That is, when the projection screen 21 is rolled and wound onto the roll assembly 22, the spacing between the reinforcing ribs 23 on the projection screen 21 is positively correlated with the number of layers of the projection screen 21. Furthermore, the spacing between the reinforcing ribs 23 on the outermost layers of the projection screen 21 is larger. This ensures that when the projection screen 21 is wound into multiple layers on the roll assembly 22, at least two reinforcing ribs 23 located on different layers of adjacent projection screens 21 have overlapping orthographic projections on the roll assembly 22.

[0070] Figure 18 This is a schematic diagram of another rollable and height-adjustable projection screen 20 provided in this application embodiment. Please refer to it. Figure 18In an optional embodiment, all layers of the multi-layer projection screen 21, except for the first layer 211, can also have a transition zone q1. When the projection screen 21 is wound into multiple layers on the roll assembly 22, the orthographic projection of the transition zone q1 in the other layers of the projection screen 21 onto the roll assembly 22 overlaps with the orthographic projection of the transition zone q1 in the first layer 211 onto the roll assembly 22. The thickness of the plurality of reinforcing ribs 23 located in the transition zone q1 of the other layers of the projection screen 21 in the direction perpendicular to the back surface of the projection screen 21 is positively correlated with a second distance, which is the shortest distance between the reinforcing rib 23 and the second edge, which is the edge of the other layers of the projection screen 21 closest to the first edge b1 when the projection screen 21 is unfolded. That is, the thickness of the plurality of reinforcing ribs 23 can also gradually increase in the transition zone q1 of the other layers of the projection screen 21, except for the first layer 211. This ensures a smooth transition in the transition zone q1 of the multi-layer projection screen 21 during the winding process, resulting in more uniform stress on the projection screen 21. It also prevents creases or wrinkles from being caused by pressure from the first edge b1 or reinforcing rib 23 on the wound projection screen 21.

[0071] In an optional embodiment, the plurality of reinforcing ribs 23 may include a plurality of target reinforcing ribs 236, which may be located in a plurality of transition zones q1 in the multi-layer projection screen 21. When the projection screen 21 is wound into multiple layers on the roll assembly 22, the orthographic projections of two adjacent target reinforcing ribs 236 on the roll assembly 22 may overlap. Furthermore, the thickness of the plurality of target reinforcing ribs 236 in the direction perpendicular to the back surface of the projection screen 21 may be positively correlated with a third distance, which may be the shortest distance between the target reinforcing rib 236 and the roll assembly 22. The target reinforcing rib 236 may be the first reinforcing rib 23 among the plurality of reinforcing ribs 23 arranged along the rolling direction f2 of the projection screen 21 in the i-th layer of the multi-layer projection screen 21. That is, the thickness of the plurality of stacked target reinforcing ribs 236 may gradually increase along the direction away from the roll assembly 22. This ensures a smooth transition in the transition zone q1 of the multi-layer projection screen 21 during the winding process, resulting in more uniform stress on the projection screen 21. It also prevents creases or wrinkles from being caused by pressure from the first edge b1 or reinforcing rib 23 on the wound projection screen 21.

[0072] In summary, this application provides a rollable and height-adjustable projection screen including a projection screen, a roll-up assembly, and multiple reinforcing ribs. The projection screen has a transition area connected to a first edge, and the thickness of the multiple reinforcing ribs located in the transition area in the direction perpendicular to the back of the projection screen is positively correlated with a first distance. Thus, when the projection screen is rolled up and wound onto the roll-up assembly, the multiple reinforcing ribs in the transition area, with their gradually increasing thickness, can support the projection screen on the side of the transition area away from the roll-up assembly. This allows the distance between the projection screen and the roll-up assembly to gradually increase as the projection screen is wound onto the side of the transition area away from the roll-up assembly, and the projection screen can smoothly transition at the location of the first edge. This avoids creases or wrinkles caused by the edge of the projection screen being squeezed after winding, improving the flatness of the projection screen and solving the problem of poor display effect in related technologies for rollable and height-adjustable projection screens, thereby improving the display effect of the projection screen.

[0073] Figure 19 This is a schematic diagram of the structure of a laser projection system 30 provided in an embodiment of this application. Please refer to it. Figure 19 The laser projection system 30 may include a rollable and liftable projection screen 20 and a laser projection device 40. The rollable and liftable projection screen 20 may be the rollable and liftable projection screen 20 in any of the above embodiments, and the front side of the rollable and liftable projection screen 20 may be a Fresnel structure.

[0074] The laser projection device 40 may include a storage unit 41 and a projector (not shown). The storage unit 41 is used to store the projector and the rollable projection screen 20. The storage unit 41 may have a light-transmitting area 411 and an opening 412. The light beam emitted from the projector can pass through the light-transmitting area 411, and the projection screen 21 passes through the opening 412 and unfolds. In this way, when the projection device is not in use, the projector and the rollable projection screen 20 are stored in the storage unit 41, which saves space. When the projection device is in use, the projection screen 21 unfolds, and the projector projects a light beam onto the projection screen 21 so that the projection screen 21 displays the projected image.

[0075] The vertical distance from the center point of the light-transmitting area 411 to the plane where the unfolded projection screen 21 is located is equal to the product of the projection ratio of the projector and the width of the display area on the screen. The width of the display area refers to the dimension of the display area along the horizontal direction. This ensures that the light beam emitted by the projector can be accurately projected onto the display area of ​​the projection screen 21, thereby ensuring the clarity of the projected image on the projection screen 21.

[0076] Since the throw ratio is a performance parameter of the projector itself, it is related to the selected projector. Different projectors result in different throw ratios, and consequently, different vertical distances from the center point of the light-transmitting area 411 to the plane of the unfolded projection screen 21. Therefore, in actual setup, the vertical distance from the center point of the light-transmitting area 411 to the plane of the unfolded projection screen 21 is calculated using the projector's throw ratio and the width of the display area. This ensures that the beam emitted by the projector can be completely projected onto the display area of ​​the projection screen 21.

[0077] In one exemplary embodiment, the rollable and lifting projection screen provided in this application may further include a crossbeam, which may be located at the other end of the rollable and lifting projection screen opposite to the roll assembly, and may be used to support that end of the rollable and lifting projection screen.

[0078] Furthermore, the rollable and liftable projection screen provided in this application embodiment can be a pull-down type or an pull-up type. When the rollable and liftable projection screen is a pull-down type, after it is set in a preset position, the user can pull the projection screen out from the roll assembly from top to bottom. When the rollable and liftable projection screen is a pull-up type, after it is set in a preset position, the user can pull the projection screen out from the roll assembly from bottom to top. In this case, the pulled-out projection screen can be fixed in a preset position (such as a hook on the wall, or by fixing the projection screen and supporting structure layer with a bracket).

[0079] Optionally, the projector can be an ultra-short-throw projector, which can be a DLP (Digital Light Processing) projector. This shortens the distance between the projector and the plane of the rollable projection screen 20, enabling a miniaturized design of the entire projection device. The projector may include a light source, an optical engine, and a lens (not shown in the figure). The light source emits a light beam to the optical engine.

[0080] In this application, the term "at least one of A and B" merely describes the relationship between related objects, indicating that three relationships can exist. For example, "at least one of A and B" can represent: A existing alone, A and B existing simultaneously, and B existing alone. Similarly, "at least one of A, B, and C" indicates that seven relationships can exist, representing: A existing alone, B existing alone, C existing alone, A and B existing simultaneously, A and C existing simultaneously, C and B existing simultaneously, and A, B, and C existing simultaneously. Likewise, "at least one of A, B, C, and D" indicates that fifteen relationships can exist, representing: A existing alone, B existing alone, C existing alone, D existing alone, A and B existing simultaneously, A and C existing simultaneously, A and D existing simultaneously, C and B existing simultaneously, D and B existing simultaneously, C and D existing simultaneously, A, B, and C existing simultaneously, A, B, and D existing simultaneously, A, C, and D existing simultaneously, and A, B, C, and D existing simultaneously.

[0081] In this application, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" means two or more, unless otherwise expressly defined.

[0082] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rollable and height-adjustable projection screen, characterized in that, include: Projection screen, roll assembly, and multiple reinforcing ribs; The first side of the projection screen is connected to the roll assembly; At least a portion of the projection screen is capable of being rolled up and wound around the roll assembly, and the front side of the projection screen is used to display the projected image. The plurality of reinforcing ribs are located on the back of the projection screen and are connected to the projection screen. The plurality of reinforcing ribs are arranged along the curling direction of the projection screen. The projection screen has a transition area connected to the first edge. The thickness of a plurality of reinforcing ribs located in the transition area in the direction perpendicular to the back of the projection screen is positively correlated with a first distance, which is the shortest distance between the reinforcing rib and the first edge. The projection screen can be wound into multiple layers on the roll assembly; the transition zone is located in the first layer of the projection screen that is closest to the first edge among the multiple layers of the projection screen, and the ratio of the area of ​​the transition zone to the area of ​​the first layer of the projection screen is greater than two-fifths. Along the length of the roll assembly, the length of the reinforcing rib is greater than or equal to the length of the projection screen.

2. The rollable and height-adjustable projection screen according to claim 1, characterized in that, Of the plurality of reinforcing ribs, except for the reinforcing rib located in the transition zone, the other reinforcing ribs have the same thickness in the direction perpendicular to the back of the projection screen.

3. The rollable and height-adjustable projection screen according to claim 1, characterized in that, The reinforcing rib includes a strip-shaped wrapping structure and a strip-shaped supporting structure; The length direction of the wrapping structure is parallel to the length direction of the support structure, and the wrapping structure wraps the support structure. The wrapping structure is fixedly connected to the back of the projection screen. The hardness of the supporting structure is greater than the hardness of the wrapping structure; Alternatively, the rigidity of the support structure is greater than the rigidity of the projection screen, and the rigidity of the projection screen is greater than the rigidity of the wrapping structure.

4. The rollable and height-adjustable projection screen according to claim 1, characterized in that, The reinforcing rib includes a reinforcing rib body and multiple strip-shaped cores; The length direction of the reinforcing rib body is parallel to the length direction of the core body, and a plurality of the core bodies are distributed inside the reinforcing rib body along a length direction perpendicular to the length direction of the reinforcing rib body; The hardness of the core is greater than the hardness of the reinforcing rib body; Alternatively, the hardness of the core is greater than the hardness of the projection screen, and the hardness of the projection screen is greater than the hardness of the reinforcing rib body.

5. The rollable and height-adjustable projection screen according to claim 1, characterized in that, The reinforcing rib has a first end face and a second end face opposite each other along the length direction of the reinforcing rib, and a plurality of side faces connecting the first end face and the second end face, wherein the connection position of two adjacent side faces has a rounded corner structure.

6. The rollable and height-adjustable projection screen according to claim 1, characterized in that, The first projection screen also includes a regular area, which is connected to the transition area in the first projection screen; In the multi-layered projection screen, all layers of the projection screen except the first layer also have transition zones and regular zones; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projection of the transition area in the other layers of the projection screen onto the roll assembly overlaps with the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly. The orthographic projection of the regular area in the other layers of the projection screen onto the roll assembly is offset from the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly. Circumferential distance between the first reinforcing rib and the second reinforcing rib d i ’ Satisfy the following formula: ; Wherein, the first reinforcing rib is the first i The last of a plurality of reinforcing ribs arranged along the curling direction of the projection screen, the second reinforcing rib being the first... i The first of a plurality of reinforcing ribs arranged along the curling direction of the projection screen on the +1 layer of projection screen. d i For the first i The circumferential distance between two adjacent reinforcing ribs in the conventional area of ​​a layered projection screen. h i The difference between the shortest distance between the second reinforcing rib and the shortest distance between the first reinforcing rib and the roll assembly. R i For the first i The radius of the regular area in the layered projection screen.

7. The rollable and height-adjustable projection screen according to claim 1, characterized in that, In the multi-layered projection screen, all layers of projection screen except the first layer also have transition zones; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projection of the transition area in the other layers of the projection screen onto the roll assembly and the orthographic projection of the transition area in the first layer of the projection screen onto the roll assembly have an overlapping area. The thickness of the multiple reinforcing ribs in the transition area of ​​the other layers of the projection screen in the direction perpendicular to the back of the projection screen is positively correlated with the second distance, which is the shortest distance between the reinforcing rib and the second edge, which is the edge of the other layers of the projection screen close to the first edge when the projection screen is unfolded.

8. The rollable and height-adjustable projection screen according to claim 7, characterized in that, The plurality of reinforcing ribs includes a plurality of target reinforcing ribs, which are respectively located in a plurality of transition zones in the multiple layers of the projection screen; When the projection screen is wound into multiple layers on the roll assembly, the orthographic projections of two adjacent target reinforcing ribs on the roll assembly overlap. The thickness of the plurality of target reinforcing ribs in the direction perpendicular to the back of the projection screen is positively correlated with the third distance, which is the shortest distance between the target reinforcing ribs and the roll assembly.

9. The rollable and height-adjustable projection screen according to claim 1, characterized in that, The rollable and height-adjustable projection screen also includes a connecting part located between the projection screen and the reinforcing ribs, the connecting part being fixedly connected to the back of the projection screen and the plurality of reinforcing ribs respectively; In a direction perpendicular to the back of the projection screen, the thickness of the connecting portion is less than the thickness of the projection screen and less than the thickness of the reinforcing rib.

Images