Projection screen and projection equipment

Abstract

A projection screen and projection equipment belong to the technical field of projection. The projection screen comprises a projection curtain, a curtain rolling assembly and a simple rolling assembly. The roller shutter assembly is located on the back face of the projection curtain, and the first end of the projection curtain and the first end of the roller shutter assembly are both connected with the roller shutter assembly. The roller shutter assembly comprises a plurality of supporting strips, and the supporting strips are sequentially arranged in the rolling direction of the projection curtain. At least part of the supporting strips in the roller shutter assembly have thermal expansion characteristics, the ratio of the thermal expansion coefficient of the projection curtain to the thermal expansion coefficient of at least part of the supporting strips with the thermal expansion characteristics is smaller than or equal to a target threshold value, and the target threshold value is larger than or equal to 1. According to the projection screen, the probability of undesirable phenomena of edge curling or internal unevenness of the projection screen is effectively reduced.

Description

Projection screens and projection equipment

[0001] This application claims priority to Chinese patent application No. 202211339691.9 filed on October 28, 2022, with application name “Projection Screen”, and priority to Chinese patent application No. 202310094352.7 filed on January 31, 2023, with application name “Projection Screen and Projection Device”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of projection technology, and in particular to projection screens and projection equipment. Background Art

[0003] The laser projection system mainly includes: a projection screen and a projection device. The projection screen is a device used to receive the image projected by the projector. The projection device is used to project a projection beam to the projection screen to display the projection image on the projection screen.

[0004] A projection screen generally includes a projection screen and a rolling mechanism. One side of the projection screen is connected to the rolling mechanism, and the projection screen in an unfolded state can be retracted by controlling the rolling mechanism.

[0005] However, after being unfolded and folded multiple times, the projection screen is very likely to have curled edges or uneven interior, resulting in problems such as distortion of the projected image on the projection screen, resulting in poor display effect of the projected image on the projection screen.

[0006] Public content

[0007] On one hand, the present application provides a projection screen, the projection screen comprising: a projection screen, a rolling curtain assembly, and a roller assembly;

[0008] The rolling curtain assembly is located on the back of the projection screen, and the first end of the projection screen and the first end of the rolling curtain assembly are both connected to the roller assembly;

[0009] The rolling curtain assembly includes a plurality of support bars, and the plurality of support bars are arranged in sequence along the curling direction of the projection screen;

[0010] At least part of the support strips in the rolling curtain assembly have thermal expansion characteristics, and the ratio of the thermal expansion coefficient of the projection screen to the thermal expansion coefficient of at least part of the support strips having the thermal expansion characteristics is less than or equal to a target threshold, and the target threshold is greater than or equal to 1.

[0011] On the other hand, the present application provides a projection device, which includes a projector and any of the projection screens described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0013] FIG1 is an effect diagram of a linear cursor image presented when a projection screen shown in the related art is not expanded by heat;

[0014] FIG2 is a diagram showing the effect of a linear cursor image presented when a projection screen is heated and expanded as shown in the related art;

[0015] FIG3 is a rear view of a first exemplary projection screen provided in an embodiment of the present application;

[0016] FIG4 is a side view of the projection screen shown in FIG3;

[0017] FIG5 is an effect diagram of a linear cursor image presented when the projection screen shown in FIG3 is not expanded due to heat;

[0018] FIG6 is a rendering of a linear cursor image presented when the projection screen shown in FIG3 expands due to heat;

[0019] FIG7 is a side view of a second exemplary projection screen provided in an embodiment of the present application;

[0020] FIG8 is a side view of a third exemplary projection screen provided in an embodiment of the present application;

[0021] FIG9 is a side view of a fourth exemplary projection screen provided in an embodiment of the present application;

[0022] FIG10 is a side view of a fifth exemplary projection screen provided in an embodiment of the present application;

[0023] FIG11 is a side view of a sixth exemplary projection screen provided in an embodiment of the present application;

[0024] FIG12 is a schematic structural diagram of a seventh exemplary projection screen provided in an embodiment of the present application;

[0025] FIG13 is a schematic diagram of a connection between a tensioning rope and a support bar provided in an embodiment of the present application;

[0026] FIG14 is a schematic diagram of the connection between a support bar and a projection screen provided in an embodiment of the present application;

[0027] FIG15 is a dimensioned diagram of a projection screen in an unfolded state provided by an embodiment of the present application;

[0028] FIG16 is a side view of an eighth exemplary projection screen provided in an embodiment of the present application;

[0029] FIG17 is a side view of a ninth exemplary projection screen provided in an embodiment of the present application;

[0030] FIG18 is a side view of a ninth exemplary projection screen provided in an embodiment of the present application;

[0031] FIG19 is a schematic diagram of an enlarged structure of a partial area of ​​the projection screen shown in FIG18;

[0032] FIG20 is a schematic structural diagram of a first exemplary flexible support strip in a projection screen provided in an embodiment of the present application;

[0033] FIG21 is a schematic structural diagram of a second exemplary flexible support strip in a projection screen provided in an embodiment of the present application;

[0034] FIG22 is a side view of a tenth exemplary projection screen provided in an embodiment of the present application;

[0035] FIG23 is a schematic diagram of an enlarged structure of a partial area of ​​the projection screen shown in FIG22;

[0036] FIG24 is a side view of an eleventh exemplary projection screen provided in an embodiment of the present application;

[0037] FIG25 is a side view of a twelfth exemplary projection screen provided in an embodiment of the present application;

[0038] FIG26 is a schematic structural diagram of a thirteenth exemplary projection screen provided in an embodiment of the present application;

[0039] FIG27 is a schematic diagram of the left side structure of the support bar in the projection screen shown in FIG26;

[0040] FIG28 is a schematic structural diagram of a fourteenth exemplary projection screen provided in an embodiment of the present application;

[0041] FIG29 is a schematic structural diagram of a fifteenth exemplary projection screen provided in an embodiment of the present application;

[0042] FIG30 is a schematic structural diagram of a laser projection device provided in an embodiment of the present application;

[0043] FIG31 is a schematic structural diagram of another laser projection device provided in an embodiment of the present application.

[0044] The accompanying drawings respectively represent: 000, projection screen; 100, roller assembly; 101, first roller; 102, second roller; 103, third roller; 200, projection screen; 2000, screen body; 300, rolling curtain assembly; 30, support bar; 30a, soft-hard combination support bar; 30b, hard support bar; 301, support bar main structure; 302, connecting structure; 303, reinforcing rib; 3000, support bar body; 3001, limiting rope; 3002, tensioning wire; 3003, limiting hole; a11, first magnetic particle; a12, second magnetic particle; g, support bar group; 400, connecting part; 401, connecting sheet; 402, connecting bar; 400a, magnetic sheet; 4001, first magnetic structure; 4002, second magnetic structure; 4003, third magnetic structure; 500, base; 600, lifting mechanism; 601, beam; 001, projection host; 002, storage device; 0021, light-transmitting area; 0022, opening.

[0045] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in this application are all explained using the accompanying drawings as examples, but changes can be made as needed, and all changes are included in the scope of protection of this application. The drawings in this application are only used to illustrate relative position relationships and do not represent true proportions.

[0047] In the related art, referring to Figures 1 and 2 , to prevent the projection screen 10 from curling or becoming uneven at the edges after being repeatedly unfolded and retracted by the lifting and retracting mechanisms, multiple support bars 20 are installed on the back of the projection screen 10. However, the thermal / humidity expansion coefficient of the support bars 20 is much smaller than that of the projection screen 10. For example, when the support bars 20 are carbon fiber sheets, the thermal expansion coefficient of the carbon fiber sheets is typically 0.57 microstrain / degree, while the thermal expansion coefficient of the projection screen 10 is typically 60 microstrain / degree. Therefore, when the projection screen 10 is exposed to high temperatures, the thermal expansion of the projection screen 10 in the projection screen 10 is much greater than that of the carbon fiber sheets. When the projection screen 10 is connected to the carbon fiber sheets, the thermal expansion exerts pressure on the smaller carbon fiber sheets, causing them to buckle and deform, resulting in poor flatness on the front surface of the projection screen 10 connected to the carbon fiber sheets. The projected image displayed on the front of the projection screen 10 still suffers from distortion and other undesirable issues, resulting in poor display quality. However, to reduce deformation of the projection screen 10 and the carbon fiber sheets during thermal expansion, the distance between adjacent carbon fiber sheets is typically increased. However, this improves the flatness of only a small portion of the projection screen 10, limiting the effectiveness of the carbon fiber sheets in improving the overall strength of the projection screen 10.

[0048] For example, please refer to Figures 1 and 2. Figure 1 is a rendering of a linear cursor image presented by a projection screen shown in the related art when it is not thermally expanded, and Figure 2 is a rendering of a linear cursor image presented by a projection screen shown in the related art when it is thermally expanded. When the projection screen 00 is not thermally expanded, each support bar 20 is able to effectively support the projection screen 10, ensuring good flatness on the front of the projection screen 10, and the cursor image 30 presented on the projection screen 10 is not significantly distorted. When the projection screen 00 is thermally expanded, each support bar 20 will bend and deform due to the thermal expansion of the projection screen 10, resulting in poor flatness on the front of the projection screen 10 and significant distortion of the cursor image 30 presented on the projection screen 10.

[0049] Please refer to Figures 3 and 4. Figure 3 is a rear view of a projection screen provided in an embodiment of the present application, and Figure 4 is a side view of a projection screen provided in an embodiment of the present application. Both Figures 3 and 4 illustrate that the multiple support bars 30 in the rolling curtain assembly 300 all have thermal expansion characteristics (the support bars 30 may also be referred to as rolling curtain strips). The projection screen 000 includes a roller assembly 100, a projection screen 200, and a roller curtain assembly 300. The roller curtain assembly 300 is located on the back of the projection screen 200. The first end of the projection screen 200 and the first end of the roller curtain assembly 300 are both connected to the roller assembly 100.

[0050] The rolling screen assembly 300 includes a plurality of support bars 30, which are arranged sequentially along the curling direction of the projection screen 200. At least some of the support bars 30 in the rolling screen assembly 300 have thermal expansion characteristics. The support bars 30 with thermal expansion characteristics meet the following conditions: the ratio of the thermal expansion coefficient of the projection screen 200 to the thermal expansion coefficient of at least some of the support bars 30 with thermal expansion characteristics is less than or equal to a target threshold, where the target threshold is greater than or equal to 1.

[0051] At least a portion of the projection screen 200 in the projection screen 000 can be rolled up and wound around the roller assembly 100, and the front of the projection screen 200 can be used to display the projection image. The rolling curtain assembly 300 is located on the back of the projection screen 200, and the multiple support bars 30 in the rolling curtain assembly 300 can all be fixedly connected to the back of the projection screen 200.

[0052] In an embodiment of the present application, at least part of the support strips 30 in the roller blind assembly 300 has thermal expansion characteristics, and at least part of the support strips 30 with thermal expansion characteristics is made of a material with thermal expansion characteristics. For example, the support strip 30 with thermal expansion characteristics includes a first part and a second part, and one of the first part and the second part is made of a material with thermal expansion characteristics, or the entire support strip 30 with thermal expansion characteristics is made of a material with thermal expansion characteristics.

[0053] As an example, a ratio of a thermal expansion coefficient of the projection screen 200 to a thermal expansion coefficient of a portion of the support bar 30 having the thermal expansion feature is less than or equal to a target threshold.

[0054] In another example, the ratio of the thermal expansion coefficient of the projection screen 200 to the thermal expansion coefficient of the entire support bar 30 having thermal expansion characteristics is less than or equal to the target threshold.

[0055] In the embodiment of the present application, the target threshold is set to be greater than or equal to 1. That is, the thermal expansion coefficient of the projection screen 200 is greater than or equal to the thermal expansion coefficient of at least a portion of the support strips 30 with thermal expansion characteristics. In this way, it is ensured that even if the support strips 30 with thermal expansion characteristics expand due to heat, their degree of thermal expansion is always less than or equal to the degree of thermal expansion of the projection screen 200, so that the support strips 30 with thermal expansion characteristics always stably support the projection screen 200.

[0056] For example, when the ratio of the thermal expansion coefficient of the projection screen 200 to the thermal expansion coefficient of the support bar 30 having thermal expansion characteristics is less than or equal to the target threshold, the value of the target threshold may be 3.

[0057] For example, the ratio of the thermal expansion coefficient of the projection screen 200 to the thermal expansion coefficient of the support bar 30 having thermal expansion characteristics includes but is not limited to 3, 2.5, 2, 1.5, 1.4, 1.3, 1.2, 1.1, 1, etc.

[0058] It should be noted that, in actual applications, different target thresholds may be selected according to the size of the projection screen 200 and the diameter of the roller assembly 100 for rolling up the projection screen 200 , and the embodiment of the present application does not impose any specific limitation on this.

[0059] In the embodiment of the present application, a plurality of support bars 30 with thermal expansion characteristics that are fixedly connected to the back of the projection screen 200 are arranged along the curling direction of the projection screen 200, and the ratio of the thermal expansion coefficient of the projection screen 200 to the thermal expansion coefficient of at least a portion of the support bars 30 with thermal expansion characteristics is less than or equal to a target threshold value, so that the thermal expansion coefficient of the projection screen 200 is close to the thermal expansion coefficient of the support bars 30 with thermal expansion characteristics. In this way, when the projection screen 200 is in a high temperature environment, the degree of thermal expansion of the projection screen 200 is close to the degree of thermal expansion of the support bars 30 with thermal expansion characteristics. Therefore, after the projection screen 200 expands due to heat, the pressure exerted on the support bars 30 with thermal expansion characteristics is relatively small, so that the degree of buckling deformation of the support bars 30 with thermal expansion characteristics is relatively small, and the multiple support bars 30 with thermal expansion characteristics can effectively support the projection screen 200. In this way, after the projection screen 200 is unfolded and folded multiple times, the probability of the projection screen 200 having edge curling or internal unevenness is effectively reduced.

[0060] In some implementations, the structural strength and bending stiffness of the projection screen 200 are respectively less than the structural strength and bending stiffness of at least a portion of the support bar 30 with thermal expansion characteristics. For example, the structural strength and bending stiffness of a partial area of ​​the support bar 30 with thermal expansion characteristics are greater than the structural strength and bending stiffness of the projection screen 200, or the structural strength and bending stiffness of the entire area of ​​the support bar 30 with thermal expansion characteristics are greater than the structural strength and bending stiffness of the projection screen 200.

[0061] In one embodiment, the thickness of the support strip 30 with thermal expansion characteristics can be greater than the thickness of the projection screen 200 in a direction perpendicular to the back of the projection screen 200. The "thickness" herein refers to the direction perpendicular to the back of the projection screen 200. For example, when the support strip 30 is a rectangular strip structure, the above-described method can easily achieve a structural strength and bending stiffness of the support strip 30 with thermal expansion characteristics that is greater than that of the projection screen 200. This ensures that the support strip 30 can effectively support the projection screen 200, thereby ensuring a good flatness of the front of the projection screen 200 and effectively reducing the probability of distortion and other defects in the projected image presented on the front of the projection screen 200.

[0062] For example, please refer to Figures 5 and 6. Figure 5 is a rendering of a linear cursor image presented when the projection screen 200 shown in Figure 3 is not heated and expanded, and Figure 6 is a rendering of a linear cursor image presented when the projection screen 200 shown in Figure 3 is heated and expanded.

[0063] As shown in FIG5 , when the projection screen 200 is not thermally expanded, each support bar 30 with thermal expansion characteristics can effectively support the projection screen 200, ensuring good flatness on the front surface of the projection screen 200. A long cursor image A1 is projected onto the projection screen 200, extending along the curled direction of the projection screen 200, without significant distortion.

[0064] As shown in FIG6 , when the projection screen 200 and the thermally expandable support strips 30 expand due to heat / humidity, the degree of buckling and deformation of the projection screen 200 and the thermally expandable support strips 30 are similar, ensuring that the thermally expandable support strips 30 can effectively support the projection screen 200, thereby ensuring good flatness on the front surface of the projection screen 200. A long cursor image A2 is projected onto the projection screen 200, and this image also exhibits no noticeable distortion.

[0065] Because the thermal expansion coefficient of the projection screen 200 is close to that of the support strips 30 with thermal expansion characteristics, the spacing between each two adjacent support strips 30 with thermal expansion characteristics among the plurality of support strips 30 with thermal expansion characteristics can be set to ensure that the area corresponding to the plurality of support strips 301 with thermal expansion characteristics on the projection screen 200 remains flat. For example, the ratio of the spacing between two adjacent support strips 30 with thermal expansion characteristics to the width of the support strip 301 with thermal expansion characteristics is set to 1:(0.5-2), thereby reducing the spacing. In this way, the flatness of the corresponding area of ​​the projection screen 200 can be effectively improved.

[0066] In the embodiment of the present application, the materials of the projection screen 200 and the support strips 30 with thermal expansion characteristics can be the same or different, provided that the thermal expansion coefficient relationship between the projection screen 200 and the support strips 30 with thermal expansion characteristics is satisfied.

[0067] For example, the projection screen 200 and the support bar 30 with thermal expansion characteristics are made of the same material, which includes: the projection screen 200 and at least a portion of the support bar 30 with thermal expansion characteristics are made of polyethylene terephthalate (PET).

[0068] For example, the entire region of the support bar 30 having thermal expansion characteristics can be made of PET material, or at least a portion of the region of the support bar 30 having thermal expansion characteristics can be made of PET material. For example, as described below, the support bar main structure 301 of the support bar 30 is a hard structure made of PET material, thereby enabling the support bar main structure 301 to have thermal expansion characteristics. The connecting structure 302 of the support bar 30 is made of a flexible material other than PET.

[0069] In practical applications, the thickness and width of the support bars 30 with thermal expansion characteristics and the distance between two adjacent support bars 30 with thermal expansion characteristics can be set according to the size of the projection screen 200 and the winding diameter of the projection screen 200 .

[0070] In actual use, the portion of the projection screen 200 wound around the reel assembly 100 is prone to creep, while the portion not wound around the reel assembly 100 is less likely to creep. Therefore, the corresponding areas of the projection screen 200 not wound around the reel assembly 100 can be free of thermal expansion support bars 30 or the spacing between adjacent thermal expansion support bars 30 can be increased. This reduces the number of thermal expansion support bars 30 used, thereby reducing the overall weight of the projection screen 200.

[0071] In other possible implementations, the projection screen 200 and the support bar 30 with thermal expansion characteristics can also be made of other materials different from polyethylene terephthalate, as long as the thermal expansion coefficient of the projection screen 200 and the thermal expansion coefficient of the support bar 30 are similar. The embodiments of the present application do not make specific limitations on this.

[0072] FIG7 is a side view of another projection screen provided in an embodiment of the present application. As shown in FIG7 , the projection screen 200 and the support bars 30 with thermal expansion characteristics in projection screen 000 are integrally molded, i.e., the two are formed as one piece. For example, the projection screen 200 and the support bars 30 with thermal expansion characteristics can be simultaneously formed through a single injection molding process. This effectively simplifies the connection process between the projection screen 200 and the support bars 30 with thermal expansion characteristics in projection screen 000, and effectively ensures the connection accuracy between the projection screen 200 and the multiple support bars 30.

[0073] In some implementations, at least a portion of the support strips 30 in the rolling blind assembly 300 provided in the embodiment of the present application has a flexible feature, and at least a portion of the support strips 30 having the flexible feature is a flexible structure.

[0074] It can be understood that the flexible feature makes at least a portion of the support bar 30 a flexible structure, that is, a partial area of ​​the support bar 30 having the flexible feature is a flexible structure, or the entire area is a flexible structure.

[0075] One example is, referring to FIG. 20 , FIG. 21 or FIG. 23 , the support bar 30 with a flexible structure is a hard-soft combined support bar 30 a , and a partial area of ​​the hard-soft combined support bar 30 a is a flexible structure.

[0076] As another example, referring to FIG. 23 , at least a portion of the support bars 30 of the rolling blind assembly 300 is a hard support bar 30 b , and the entire area of ​​the hard support bar 30 b is a rigid structure.

[0077] By arranging a support bar 30 with flexible characteristics in the rolling curtain assembly 300, when the projection screen 200 is rolled up, the support bar 30 with flexible characteristics can reduce its wear and extrusion force on the projection screen 200, thereby solving the problem of easy damage to the projection screen in the related art and improving the protection effect of the projection screen 200.

[0078] In addition, since the support bar 30 has a flexible feature and reduces its squeezing force on the projection screen 200 , it can avoid the occurrence of indentations on the projection screen 200 and improve the display effect of the projection screen 200 .

[0079] In addition, the provision of the support strip 30 with flexible characteristics can also enhance the curling ability of the roller blind assembly 300, reduce the curling radius of the projection screen, and reduce the volume of the roller assembly 100, which is conducive to the miniaturization of the projection screen.

[0080] Based on the arrangement of the support bar 30 having the thermal expansion feature and the support bar 30 having the flexibility feature in the rolling blind assembly 300, the rolling blind assembly 300 can have various embodiments, as shown below:

[0081] In some examples (1), all support bars 30 in the roller blind assembly 300 have thermal expansion features.

[0082] These support bars 30 may or may not have flexible features. One example is that all the support bars 30 in the rolling shutter assembly 300 have thermal expansion features and do not have flexible features. Taking the projection screen shown in Figure 3 as an example, it illustrates that all the support bars 30 in the rolling shutter assembly 300 are support bars 30 with thermal expansion features, and these support bars 30 do not have flexible features, making them hard support bars.

[0083] In Example (1), multiple support bars 30 with thermal expansion characteristics are arranged at intervals from each other. The spacing between any two adjacent support bars 30 can be seen as described above and will not be repeated here. In addition, the support bars 30 with thermal expansion characteristics can be rectangular long strip structures, making them easy to form and prepare, and facilitating control of dimensions in all directions.

[0084] In some implementations, the roller blind assembly 300 includes a first support bar and a second support bar, wherein the first support bar has at least a thermal expansion feature, and the second support bar has a flexible feature and does not have a thermal expansion feature. This implementation may further include the following examples:

[0085] In some examples (2), the first portion of the support bar has a thermal expansion feature and no flexible feature, and the second portion of the support bar has a flexible feature and no thermal expansion feature.

[0086] The roller blind assembly 300 shown in Example (2) includes two types of support bars 30. The first type of support bar is a support bar 30 with a thermal expansion feature but no flexibility feature, and the second type of support bar is a support bar 30 with a flexibility feature but no thermal expansion feature.

[0087] The arrangement positions of different types of support bars on the projection screen 200 are determined based on the requirements of each area of ​​the projection screen 200 for buckling deformation caused by thermal expansion and wear resistance requirements such as indentation.

[0088] In example (2), the first type of support bars and the second type of support bars may be arranged independently in different regions, or the first type of support bars may be mixed with some or all of the second type of support bars. For example, one first type of support bar and one second type of support bar may be arranged alternately in sequence. Alternatively, two or more first type of support bars may be arranged at intervals in sequence to form a first support bar group, and the first support bar group and one second type of support bar or at least two second type of support bars may be arranged alternately in sequence. Alternatively, two or more second type of support bars may be arranged at intervals in sequence to form a second support bar group, and the second support bar group and one first type of support bar may be arranged alternately in sequence.

[0089] In some examples (3), a first portion of the support strip has a thermal expansion feature and a portion of the support strip 30 has a flexible feature, and a second portion of the support strip has a flexible feature and does not have a thermal expansion feature.

[0090] The roller blind assembly 300 shown in Example (3) includes three types of support strips 30. The first type of support strips are support strips 30 having thermal expansion characteristics but not flexible characteristics. The second type of support strips are support strips 30 having flexible characteristics but not thermal expansion characteristics. The third type of support strips are support strips 30 having both thermal expansion characteristics and flexible characteristics.

[0091] The arrangement positions of different types of support bars on the projection screen 200 are determined based on the requirements of each area of ​​the projection screen 200 for buckling deformation caused by thermal expansion and wear resistance requirements such as indentation.

[0092] In example (3), the first type of support bars, the second type of support bars, and the third type of support bars can be arranged independently in different regions, or any two or three of the first type of support bars, the second type of support bars, and the third type of support bars can be arranged in a mixed manner. For example, this includes that a first type of support bar, a second type of support bar, and a third type of support bar can be arranged alternately in any arrangement order. One or more first type of support bars are arranged in sequence to form a first support bar group, one or more second type of support bars are arranged in sequence to form a second support bar group, one or more third type of support bars are arranged in sequence to form a third support bar group, and any two or three of the first support bar group, the second support bar group, and the third support bar group are arranged in a mixed manner.

[0093] In some examples (4), a first portion of support bars has a thermal expansion feature and all support bars 30 also have a flexible feature, and a second portion of support bars has a flexible feature and does not have a thermal expansion feature.

[0094] The roller blind assembly 300 shown in Example (4) includes two types of support bars 30. The first type of support bar is a support bar 30 having both thermal expansion characteristics and flexible characteristics. The second type of support bar is a support bar 30 having flexible characteristics but no thermal expansion characteristics.

[0095] The arrangement positions of different types of support bars on the projection screen 200 are determined based on the requirements of each area of ​​the projection screen 200 for buckling deformation caused by thermal expansion and wear resistance requirements such as indentation.

[0096] In example (4), the first type of support bars and the second type of support bars may be arranged independently in different regions, or the first type of support bars may be mixed with some or all of the second type of support bars. For example, one first type of support bar and one second type of support bar may be arranged alternately in sequence. Alternatively, two or more first type of support bars may be arranged at intervals in sequence to form a first support bar group, and the first support bar group and one second type of support bar or at least two second type of support bars may be arranged alternately in sequence. Alternatively, two or more second type of support bars may be arranged at intervals in sequence to form a second support bar group, and the second support bar group and one first type of support bar may be arranged alternately in sequence.

[0097] In some implementations, all support bars 30 in the rolling blind assembly 300 have thermal expansion characteristics, and at least some support bars 30 in the rolling blind assembly 300 also have flexibility characteristics. This implementation may further include the following examples:

[0098] In some examples (5), all the support bars 30 in the rolling blind assembly 300 have thermal expansion characteristics, and some of the support bars 30 in the rolling blind assembly 300 also have flexibility characteristics.

[0099] The roller blind assembly 300 shown in Example (5) includes two types of support bars 30. The first type of support bar is a support bar 30 having both thermal expansion characteristics and flexibility characteristics, and the second type of support bar is a support bar 30 having thermal expansion characteristics but no flexibility characteristics.

[0100] The arrangement positions of different types of support bars on the projection screen 200 are determined based on the requirements of each area of ​​the projection screen 200 for buckling deformation caused by thermal expansion and wear resistance requirements such as indentation.

[0101] In example (5), the first type of support bars and the second type of support bars may be arranged independently in different regions, or the first type of support bars may be mixed with some or all of the second type of support bars. For example, one first type of support bar and one second type of support bar may be arranged alternately in sequence. Alternatively, two or more first type of support bars may be arranged at intervals in sequence to form a first support bar group, and the first support bar group and one second type of support bar or at least two second type of support bars may be arranged alternately in sequence. Alternatively, two or more second type of support bars may be arranged at intervals in sequence to form a second support bar group, and the second support bar group and one first type of support bar may be arranged alternately in sequence.

[0102] In some examples (6), all the support bars 30 in the rolling blind assembly 300 have a thermal expansion feature, and all the support bars 30 in the rolling blind assembly 300 also have a flexible feature.

[0103] The roller blind assembly 300 shown in Example (6) includes a type of support bar 30, which is a support bar 30 having both thermal expansion characteristics and flexibility characteristics.

[0104] In Example (6), multiple support bars 30 having thermal expansion characteristics and flexible characteristics are arranged at intervals. The spacing between any two adjacent support bars 30 can be referred to as described above and will not be repeated here. Alternatively, multiple support bars 30 having thermal expansion characteristics and flexible characteristics are arranged end-to-end fixedly connected to each other.

[0105] In the embodiment of the present application, the flexible structure involved in the support bar 30 with flexible characteristics can be obtained by using a flexible material, or by using an elastic structure, or by using a combination of a flexible material and an elastic structure.

[0106] A flexible material is a material that is inherently elastic, such as some rubber-like materials. Thus, by using a flexible material to create a flexible structure, flexibility can be imparted to the structure. An elastic structure is a structure designed to elastically deform along the curling direction of the projection screen 200, such as thin-walled arms, sheets, hollow rings, or hollow arcs. By using a target material to create a flexible structure and designing it as an elastic structure, flexibility can be imparted to the flexible structure. The target material can be either a hard material or a flexible material.

[0107] For example, using a target material with thermal expansion characteristics, the elastic structure can be fabricated using this material, ensuring that the ratio of the thermal expansion coefficient of the flexible structure to the thermal expansion coefficient of the projection screen 200 is greater than or equal to a target threshold. The "target threshold" here is consistent with the aforementioned description and will not be further elaborated. This solution is applicable to support bars 30 that exhibit both flexibility and thermal expansion characteristics.

[0108] The flexible support bars 30 can be spaced apart from adjacent support bars 30 or connected end-to-end. The flexible support bars 30 can be entirely flexible or partially flexible. The "adjacent support bars 30" referred to herein can include support bars 30 that are flexible but not thermally expandable, support bars 30 that are thermally expandable but not flexible, or support bars 30 that have both flexibility and thermal expansion characteristics.

[0109] In one example, the flexible support bars 30 are spaced apart from adjacent support bars 30 (see Figures 3-15). The flexible support bars 30 can be made of a flexible material. Alternatively, the flexible support bars 30 can be designed in a sheet or ring shape.

[0110] Another example is that the support bar 30 with flexible characteristics is movably connected to the adjacent support bar 30 at the end (see Figures 17-29). Then, the support bar 30 with flexible characteristics may include a connecting structure 302 for connecting with the adjacent support bar 30.

[0111] Another example is that in the roller blind assembly 300, there is a scheme in which the support bars 30 with flexible characteristics are spaced apart from the adjacent support bars 30, and there is also a scheme in which the support bars 30 with flexible characteristics are movably connected to the adjacent support bars 30 at their ends (see Figure 16).

[0112] In some implementations, as shown in FIG19 , the support bar 30 having flexible characteristics is a soft-hard combination support bar 30a, which includes: a support bar main body structure 301 and two connecting structures 302 respectively located at both ends of the support bar main body structure 301, at least one of the support bar main body structure 301 and the two connecting structures 302 is a flexible structure, and one structure is a hard structure; the hard structure is obtained by hard material and / or rigid structure.

[0113] The support bar with a flexible feature is connected to an adjacent support bar via a connecting structure 302. The "adjacent support bar 30" referred to herein may be a support bar 30 with a flexible feature but no thermal expansion feature, a support bar 30 with a thermal expansion feature but no flexible feature, or a support bar 30 with both a flexible feature and a thermal expansion feature.

[0114] A hard material refers to a material that is inherently rigid and not easily deformed. A rigid structure refers to a structure designed so that it cannot be elastically deformed along the curling direction of the projection screen 200, such as a thick-walled structure.

[0115] For example, using a target material with thermal expansion characteristics, a rigid structure can be fabricated using this material, ensuring that the ratio of the rigid structure's thermal expansion coefficient to that of the projection screen 200 is greater than or equal to a target threshold. The "target threshold" here is consistent with the aforementioned description and will not be further elaborated. This approach is applicable to support bars 30 that exhibit both flexibility and thermal expansion characteristics.

[0116] In some examples, the rolling curtain assembly included in the projection screen provided in the embodiments of the present application is a combined rigid and flexible rolling curtain assembly, that is, the rolling curtain assembly includes both a rigid structure and a flexible structure. This combined rigid and flexible rolling curtain assembly can, while ensuring support for the projection screen, reduce damage to the projection screen caused by the rolling curtain assembly and improve its bending performance, thereby facilitating miniaturization of the projection screen. This combined rigid and flexible rolling curtain assembly can have various structures, each of which is described below.

[0117] In one solution, part of the structure of the support strip in the rolling shutter assembly may be a flexible structure, and another part of the structure may be a hard structure. Please refer to Figure 18, which is a structural schematic diagram of a projection screen provided in an embodiment of the present application, and Figure 19 is an enlarged structural schematic diagram of a partial area of ​​the projection screen shown in Figure 18 (an enlarged structural schematic diagram of area q1 in Figure 18).

[0118] The support strips 30 in the roller blind assembly 300 shown in Figures 18 and 19 not only have flexibility, but also can have thermal expansion characteristics in at least a portion of the support strips 30. As shown in Example (6) mentioned above, all the support strips 30 have both thermal expansion characteristics and flexibility characteristics. This can be achieved by using a material having thermal expansion characteristics to prepare the entire or partial region of the support strip 30 having flexibility characteristics. The structure of the support strip 30 having flexibility characteristics is shown below.

[0119] Please refer to Figures 18 and 19, in which the support bar 30 with flexible characteristics includes: a support bar main structure 301 and two connecting structures 302 respectively located at both ends of the support bar main structure 301, at least one of the support bar main structure 301 and the two connecting structures 302 is a flexible structure, and one structure is a hard structure; the hard structure is obtained by hard material and / or rigid structure.

[0120] In this solution, the support bar 30 with flexible characteristics can be a support bar that combines soft and hard features. In this way, on the basis of improving the flexibility of the support bar 30 with flexible characteristics, the support effect of the support bar 30 with flexible characteristics on the projection screen 200 can be guaranteed, so that the projection screen 200 can maintain a high degree of flatness, especially the flatness of the edge area of ​​the projection screen.

[0121] In an exemplary embodiment, the flexible material includes at least one of silicone, thermoplastic elastomer (TPE), thermoplastic polyurethanes (TPU), polyvinyl chloride (PVC) modified soft rubber, and polyvinyl chloride modified rubber.

[0122] The hard material includes at least one of polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, carbon fiber, aluminum alloy, polycarbonate (PC) and polyvinyl chloride.

[0123] Of course, the above-mentioned flexible material and hard material may also include other materials in the art, and the embodiments of the present application are not limited thereto.

[0124] In some examples, the material of the hard structure in the support bar 30 with flexible characteristics is a material with thermal expansion characteristics, such as polyethylene terephthalate, or the material of both the hard structure and the flexible structure of the support bar 30 with flexible characteristics are materials with thermal expansion characteristics, such as polyethylene terephthalate, etc.

[0125] For example, if the material exhibiting thermal expansion characteristics is polyethylene terephthalate, the flexible structure in the flexible support bar 30 can be designed as polyethylene terephthalate to be elastically deformable along the curling direction of the projection screen 200, such as a thin-walled arm, sheet, hollow ring, or hollow arc. In this way, the flexible structure of the flexible support bar 30 also exhibits thermal expansion characteristics.

[0126] For example, if the material exhibiting thermal expansion characteristics is polyethylene terephthalate, the rigid structure of the flexible support bar 30 can be designed with thick-walled polyethylene terephthalate to maintain its inherent rigidity. In this way, the rigid structure of the flexible support bar 30 also exhibits thermal expansion characteristics.

[0127] A support bar 30 with flexible characteristics is a soft-hard combination support bar 30a, wherein the support bar main structure 301 is a hard structure, one of the two connecting structures 302 is a hard structure, and the other connecting structure 302 is a flexible structure.

[0128] For example, in the flexible support bar 30 shown in FIG19 , of the two connecting structures 302, one connecting structure 302 is a circular structure (the connecting structure 302 at the lower end of the flexible support bar 30 in FIG19 is a circular structure, which can specifically be a spherical head structure or a cylindrical structure), and the other connecting structure 302 is a C-shaped mouth structure (the connecting structure 302 at the upper end of the flexible support bar 30 in FIG19 is an arc-shaped groove structure). The circular structure can be a flexible structure, and the C-shaped mouth structure and the main support bar structure 301 are rigid structures. This structure makes one end of the flexible support bar 30 flexible, so that it can bend with the rolling curtain assembly when it bends, thereby improving the bending performance of the rolling curtain assembly, reducing the bending radius of the rolling curtain assembly, and facilitating the miniaturization of the projection screen.

[0129] Another flexible support bar 30 is a rigid-flexible support bar 30a, as shown in Figure 20. The main support bar structure 301 is rigid, while the two connecting structures 302 within the rigid-flexible support bar 30a are flexible. Specifically, the main support bar structure 301 in the middle of the rigid-flexible support bar 30a is rigid, while the connecting structures 302 at either end, used to connect to other support bars, are flexible.

[0130] Both ends of the support strip 30 with flexible features are flexible and can bend along with the rolling shutter assembly 300 when it bends, thereby improving the bending performance of the rolling shutter assembly 300 and reducing the bending radius of the rolling shutter assembly 300, which is beneficial to the miniaturization of the projection screen (this miniaturization may refer to the miniaturization of the projection screen in the storage state), and can reduce the pressure exerted by the rolling shutter assembly 300 on the projection screen 200 in the storage state, thereby reducing the risk of damage to the projection screen 200 and improving the service life of the projection screen 000.

[0131] In addition, since the friction of the flexible structure is large, this helps to improve the friction between the connecting structure 302 of the support bar 30 with flexible characteristics and the connecting structure 302 of the adjacent support bar 30 to which it is connected (the adjacent support bar 30 can be a support bar 30 with flexible characteristics or a hard support bar 30), thereby reducing the possibility of the two support bars 30 being offset in the horizontal direction (the horizontal direction can refer to the direction parallel to the axis of the reel assembly).

[0132] Another type of support bar 30 with flexible features is a combination of soft and hard support bar 30a, as shown in Figure 21. The support bar main structure 301 is a flexible structure, while the two connecting structures 302 in the flexible support bar 30 are rigid structures. That is, the connecting structures 302 at both ends of the flexible support bar 30 are rigid structures, while the middle support bar main structure 301 is a flexible structure. The middle support bar main structure 301 can bend with the rolling curtain assembly 300, improving the bending performance of the rolling curtain assembly 300 and reducing the bending radius of the rolling curtain assembly 300. This is conducive to the miniaturization of the projection screen, and can also reduce the pressure exerted by the rolling curtain assembly 300 on the projection screen 200 in the stored state, reducing the risk of damage to the projection screen 200 and increasing the service life of the projection screen.

[0133] When the rolling shutter assembly 300 of the projection screen provided in the embodiment of the present application includes a plurality of support strips 30 with flexible characteristics, the plurality of support strips 30 with flexible characteristics may include at least one of the plurality of support strips 30 with flexible characteristics mentioned above, that is, the structures of the plurality of support strips 30 with flexible characteristics in the rolling shutter assembly 300 may be the same, or the structures of the plurality of support strips 30 with flexible characteristics in the rolling shutter assembly 300 may not be completely the same.

[0134] In an exemplary embodiment, as shown in FIG17 , each support bar 30 in the rolling shutter assembly 300 can be the above-mentioned support bar 30 with flexible characteristics, and then each support bar 30 can be a soft-hard combination support bar 30a, which can improve the overall bending performance of the rolling shutter assembly 300 and reduce the possibility of each support bar 30 damaging the projection screen.

[0135] In another exemplary embodiment, as shown in FIG16 , in a roller blind assembly 300 provided in an embodiment of the present application, some support bars are flexible and rigid support bars 30a, while the remaining support bars 30 may be rigid support bars 30b made of a rigid material. FIG16 also shows that adjacent flexible and rigid support bars 30a are movably connected end to end, and that adjacent rigid support bars 30b are spaced apart at a predetermined distance.

[0136] In some implementations, as shown in Figures 22 and 23, the plurality of support bars 30 in the rolling blind assembly 300 includes a plurality of support bar groups g, each of which includes at least two connected support bars 30. Each support bar group g includes at least one flexible support bar 30 (e.g., a rigid-flexible support bar 30a) and at least one rigid support bar 30b. The rigid-flexible support bar 30a and the rigid support bar 30b are prepared as described above.

[0137] Among the multiple support strips 30 in the rolling shutter assembly 300, some support strips are support strips 30 with flexible characteristics (for example, soft and hard combined support strips 30a), and some support strips are hard support strips 30b, and the support strips 30 with flexible characteristics are distributed at multiple positions in the rolling shutter assembly 300, so that each position of the rolling shutter assembly 300 can be flexible, thereby improving the overall flexibility of the rolling shutter assembly 300.

[0138] In an exemplary embodiment, as shown in Figures 22 and 23, a support bar group g includes two connected support bars 30, and each support bar group g includes a soft-hard combination support bar 30a and a hard support bar 30b. In this embodiment, the soft-hard combination support bars 30a and the hard support bars 30b are alternately arranged in sequence in the rolling curtain assembly 300. This can improve the uniformity of the distribution of the flexible support bars 30 in the rolling curtain assembly 300, so that each area of ​​the rolling curtain assembly 300 has a certain degree of flexibility, further avoiding the possibility of the rolling curtain assembly 300 damaging the projection screen and improving the protective effect of the rolling curtain assembly 300 on the projection screen.

[0139] Of course, each support bar group g can also include a larger number of support bars 30. Correspondingly, the number of support bars 30 with flexible characteristics and hard support bars 30b in each support bar group g can also be other numbers. For example, as shown in Figure 24, Figure 24 is a structural schematic diagram of another projection screen provided in an embodiment of the present application, wherein each support bar group g can include 3 support bars 30, and each support bar group g includes two soft-hard combined support bars 30a and one hard support bar 30b.

[0140] As shown in FIG. 25 , each support bar group g may include four support bars, and each support bar group g includes two soft-hard combination support bars 30 a and two hard support bars 30 b .

[0141] In addition, although Figures 22 to 25 illustrate that two adjacent support bars 30 in each support bar group g, and two adjacent support bar groups g, are movably connected by the connecting structure 302, it is not excluded that two adjacent support bars 30 and at least one of two adjacent support bar groups g may also be arranged at a certain distance apart.

[0142] It can be seen that the embodiments of the present application provide multiple types of rolling shutter assemblies 300. For example, each support bar in the first type of rolling shutter assembly 300 is a support bar 30 with flexible characteristics (for example, a soft-hard combination support bar 30a), and the second type of rolling shutter assembly 300 may include a plurality of hard support bars 30b and a plurality of support bars 30 with flexible characteristics (for example, a soft-hard combination support bar 30a), and the hard support bars 30b and the support bars 30 with flexible characteristics are arranged alternately or at intervals.

[0143] That is, the embodiment of the present application further provides a projection screen 000, in which the rolling blind assembly 300 includes a plurality of support bars 30, the plurality of support bars 30 including a plurality of support bar groups g, each of which includes at least two connected support bars 30, and each support bar group g including at least one flexible support bar 30 (e.g., a combination of flexible and rigid support bars 30a) and at least one rigid support bar 30b. The structure of the flexible support bars 30 of the projection screen 000 provided in the embodiment of the present application can be referred to in the following example.

[0144] A flexible support bar 30 includes a main support bar structure 301 and two connecting structures 302 located at either end of the main support bar structure 301. At least one of the main support bar structure 301 and the two connecting structures 302 is a flexible structure, such as a flexible structure comprising a flexible material, and at least one of the structures is a rigid structure, such as a rigid structure comprising a rigid material. In this embodiment, the flexible support bar 30 is a combination of a soft and a rigid support bar 30a. This improves the flexibility of the flexible support bar 30 while ensuring its support for the projection screen, thereby maintaining a high degree of flatness, particularly at the edge of the projection screen.

[0145] Another flexible support bar 30 has a rigid main structure 301 and flexible connecting structures 302. Because the flexible structure has greater friction, this structure increases the friction between the connecting structure 302 of the flexible support bar 30 and the connecting structure 302 of the connected support bar, reducing the possibility of lateral deviation between the two support bars.

[0146] In another support bar 30 with flexible characteristics, the main structure 301 of the support bar is a flexible structure, and the two connecting structures 302 are hard structures.

[0147] The above descriptions respectively describe the arrangement of the plurality of support bars 30 in the rolling curtain assembly 300 and their effects. The following description will describe the combination of the rolling curtain assembly 300 and the projection screen 200 .

[0148] In some implementations, please refer to Figure 8, which is a side view of another projection screen provided in an embodiment of the present application. The projection screen 000 may further include a connecting portion 400 for connecting the projection screen 200 and the rolling curtain assembly 300. The connecting portion 400 is fixedly connected to the back surface of the projection screen 200 and the plurality of support bars 30 in the rolling curtain assembly 300. In a direction perpendicular to the back surface of the projection screen 200, the thickness of the connecting portion 400 is less than the thickness of the projection screen 200 and less than the thickness of the support bars 30.

[0149] In this case, a connecting portion 400 is provided between the projection screen 200 and the support bars 30 to secure the multiple support bars 30 to the back of the projection screen 200. This allows the projection screen 200 and the support bars 30 to be manufactured separately and then assembled together through a connecting process, without altering their respective textures and properties. Furthermore, the thickness of the connecting portion 400 is smaller than both the thickness of the projection screen 200 and the thickness of the support bars 30. This ensures that even if the connecting portion 400 expands due to heat when the projection screen 200, connecting portion 400, and support bars 30 are exposed to high temperatures, the impact on the projection screen 200 is minimal, thereby ensuring the smoothness of the projection screen 200.

[0150] As shown in FIG8 , the connecting portion 400 in the projection screen 000 may include: a whole layer of connecting pieces 401, and the orthographic projections of at least some of the multiple support bars 30 on the back of the projection screen 200 may all be located within the orthographic projections of the connecting piece 401 on the back of the projection screen 200.

[0151] And / or, as shown in FIG9 , the connecting portion 400 may include: a plurality of connecting bars 402, each of which may correspond one-to-one to at least some of the plurality of support bars 30. The orthographic projection of each connecting bar 402 on the back surface of the projection screen 200 may be located within the orthographic projection of the corresponding support bar 30 on the back surface of the projection screen 200.

[0152] As can be seen from the above, there are multiple optional implementations for the structural form of the connecting portion 400 that is respectively connected to the projection screen 200 and the multiple support bars 30. The embodiments of the present application are schematically described using the following three optional implementations as examples:

[0153] In a first alternative implementation, as shown in FIG8 , the connecting portion 400 may include a full-layer connecting sheet 401. The orthogonal projections of the multiple support bars 30 located on the back of the projection screen 200 onto the back of the projection screen 200 can all be located within the orthogonal projection of the connecting sheet 401 onto the back of the projection screen 200. In this case, the full-layer connecting sheet 401 secures the multiple support bars 30 to the back of the projection screen 200, increasing the contact area between the support bars 30 and the projection screen 200 and effectively increasing the structural strength and bending rigidity of the entire projection screen 200. Furthermore, after the projection screen 200 is unfolded, the probability of edge curling or internal unevenness is reduced, ensuring a better display quality for the projection image on the projection screen 200. Alternatively, the full-layer connecting sheet 401 can be directly connected to the back of the projection screen 200, and the multiple support bars 30 can be secured to the side of the full-layer connecting sheet 401 facing away from the projection screen 200. This simplifies the assembly process of the support bars 30 and the projection screen 200 and ensures the assembly accuracy of the multiple support bars 30 and the projection screen 200. It should be noted that the orthographic projection of the entire layer of connecting pieces 401 on the back of the projection screen 200 is located within the area where the back of the projection screen 200 is located.

[0154] For a second optional implementation, please refer to FIG9 , which is a side view of another projection screen provided in an embodiment of the present application. The connecting portion 400 may include: a plurality of connecting bars 402, which may correspond one-to-one to the plurality of support bars 30 located on the back of the projection screen 200. The positive projection of each connecting bar 402 on the back of the projection screen 200 may be located within the positive projection of the corresponding support bar 30 on the back of the projection screen 200. In this case, by providing a plurality of connecting bars 402 connected to a plurality of support bars 30 in a one-to-one correspondence, the assembly flexibility of each support bar 30 and the back of the projection screen 200 is ensured, and the overall weight of the connecting portion 400 is reduced, so that the overall weight of the projection screen 000 is smaller.

[0155] For a third optional implementation, please refer to FIG10 , which is a side view of a projection screen provided by another embodiment of the present application. The connecting portion 400 includes: a whole layer of connecting pieces 401 and a plurality of connecting bars 402. Among them, the positive projection of a portion of the plurality of support bars 30 located on the back side of the projection screen 200 on the back side of the projection screen 200 can be located within the positive projection of the connecting piece 401 on the back side of the projection screen 200. The plurality of connecting bars 402 correspond one-to-one to another portion of the plurality of support bars 30, and the positive projection of each connecting bar 402 on the back side of the projection screen 200 can be located within the positive projection of the corresponding support bar 30 on the back side of the projection screen 200.

[0156] For example, as shown in FIG10 , the back of the projection screen 200 includes a first area A3 and a second area A4 adjacent to each other along the winding direction of the projection screen 200. The entire layer of connecting pieces 401 in the connecting portion 400 can be located within the second area A4 of the back of the projection screen 200, and the plurality of connecting strips 402 can be located within the first area A3 of the back of the projection screen 200. When the projection screen 200 is retracted, a portion of the projection screen 200 is typically wound around the reel assembly 100, while another portion is not. The first area A3 can be the area of ​​the back of the projection screen 200 wound around the reel assembly 100, while the second area A4 can be the area of ​​the back of the projection screen 200 not wound around the reel assembly 100. In this way, when the projection screen 200 needs to be rolled up, the portion of the projection screen 200 corresponding to the multiple connecting strips 402 can be easily rolled up on the reel assembly 100, and the portion of the projection screen 200 corresponding to the entire layer of connecting pieces 401 has better overall structural strength and bending rigidity, ensuring that the flatness of this portion of the projection screen 200 is better.

[0157] In an embodiment of the present application, as shown in FIG9 , when the connecting portion 400 includes a plurality of connecting bars 402, the width of each connecting bar 402 can be smaller than the width of the corresponding support bar 30. Furthermore, the orthographic projection of each connecting bar 402 on the back of the projection screen 200 can be located within the central area of ​​the orthographic projection of the corresponding support bar 30 on the back of the projection screen 200. In this case, by setting the width of each connecting bar 402 smaller than the width of the corresponding support bar 30, while ensuring support for the projection screen 200 by the support bars 30, the contact area between each support bar 30 and the projection screen 200 is reduced, making it easier for the projection screen 200 to be wound onto the reel assembly 100 when folded.

[0158] Furthermore, by arranging the orthographic projection of each connecting bar 402 on the back of the projection screen 200 to be located within the central area of ​​the orthographic projection of the corresponding support bar 30 on the back of the projection screen 200, the supporting force exerted by the support bars 30 in the area connected to the back of the projection screen 200 is more evenly distributed, thereby ensuring the overall flatness of the projection screen 200. For example, as shown in FIG10 , the width of each connecting bar 402 of the multiple support bars 30 and multiple connecting bars 402 arranged in a first area A3 on the back of the projection screen 200 can be smaller than the width of the corresponding support bar 30. The first area A3 can be the area on the back of the projection screen 200 wound on the reel assembly 100, and the second area A4 can be the area on the back of the projection screen 200 not wound on the reel assembly 100.

[0159] In some implementations, the connecting portion 400 is a cohesive adhesive layer or a magnetic structure. For example, as shown in FIG11 , the magnetic structure is a magnetic sheet 400a. In this case, the plurality of support bars 30 can be fixed to the back of the projection screen 200 by bonding with the adhesive layer or by magnetically connecting the magnetic sheet 400a. For example, the adhesive layer can be any one of double-sided tape, liquid glue, or foam glue, which is not specifically limited in this embodiment of the present application.

[0160] As an example, the connecting part is a magnetic structure, as shown in Figure 28, the connecting part 400 includes a first magnetic structure 4001 and a second magnetic structure 4002, the first magnetic structure 4001 is located on the rolling shutter assembly 300, and the second magnetic structure 4002 is located on the surface of the projection screen 200 facing the rolling shutter assembly 300, and the first magnetic structure 4001 and the second magnetic structure 4002 are adsorbed on each other.

[0161] The first magnetic structure 4001 can have various structures and can be positioned in various locations. For example, in one projection screen, the first magnetic structure 4001 can be a magnetic layer that can be attached to the rolling curtain assembly 300, for example, to the side of the rolling curtain assembly 300 that is away from the projection screen 200. In this structure, the first magnetic structure 4001 can be prevented from directly contacting the second magnetic structure 4002 on the projection screen 200, thereby reducing the possibility of the first magnetic structure 4001 damaging the projection screen 31 and improving the protection of the projection screen 200. In this structure, the rolling curtain assembly can be made of a material that does not affect the mutual attraction between the first magnetic structure 4001 and the second magnetic structure 4002.

[0162] Of course, the first magnetic structure 4001 may also be attached to the surface of the rolling curtain assembly 300 facing the projection screen 200 , and this embodiment of the present application does not limit this.

[0163] In addition, the first magnetic structure 4001 may include a plurality of magnetic strips, which may be distributed on the rolling blind assembly 300 and arranged in sequence in a direction away from the roller assembly 100 .

[0164] In an exemplary embodiment, the first magnetic structure 4001 can also be incorporated into the rolling shutter assembly 300, that is, magnetic material can be doped into the support bar 30 of the rolling shutter assembly 300, or part of the structure of the support bar 30 is made of magnetic material.

[0165] As another example, the connecting portion 400 is a magnetic structure. As shown in FIG11 , the magnetic structure includes a third magnetic structure 4003 . For example, the third magnetic structure 4003 is located on the surface of the projection screen 200 facing the rolling curtain assembly 300 .

[0166] The support bar 30 includes: a support bar body 3000, and first magnetic particles a11 distributed in at least one of the interior and surface of the support bar body 3000, the first magnetic particles a11 include metal particles, and / or, the projection screen 200 includes a screen body 2000 and second magnetic particles a12 distributed in at least one of the interior and surface of the screen body 2000, the second magnetic particles a12 include metal particles.

[0167] In an embodiment of the present application, please refer to Figure 11. The third magnetic structure 4003 can be a magnetic sheet with magnetism, and the support bar 30 can include: a support bar body 3000, and metal particles (i.e., first magnetic particles a11) distributed within the support bar body 3000. In this case, by integrating metal particles within the first magnetic particles a11 of the support bar body, and using a magnetic sheet with magnetism as the connecting portion 400. In this way, the support bar 30 can be adsorbed on the back of the projection screen 200 through the magnetic sheet. The side of the magnetic sheet facing away from the support bar 30 can be bonded to the back of the projection screen 200, or particles such as magnetic powder (not shown in the figure) can be integrated into the projection screen 200 to adsorb the magnetic sheet on the back of the projection screen 200. This embodiment of the present application does not specifically limit this. Of course, it is also feasible that the projection screen 200 in Figure 11 does not contain the second magnetic particles a12.

[0168] For the solution in which the support bar 30 includes a support bar main structure 301 and two connecting structures 302, at least one of the support bar main structure 301 and the two connecting structures 302 is a flexible structure, and at least one structure is a hard structure, which can be a structure made of magnetic material. For example, the support bar main structure 301 can be a hard structure with magnetism, and the two connecting structures 302 can be flexible structures.

[0169] In some implementations, in order to prevent the multiple support bars 30 from being misplaced in a direction parallel to the projection screen 200, as shown in Figure 26, the roller shutter assembly 300 provided in the embodiment of the present application also includes at least one limiting rope 3001, which passes through the multiple support bars 30 in sequence along the curling direction of the projection screen 200; the limiting rope 3001 is configured to prevent the multiple support bars 30 from being misplaced in a direction parallel to the projection screen 200.

[0170] In an exemplary embodiment, as shown in FIG26 , the projection screen further includes at least one limiting cord 3001. The limiting cord 3001 includes a limiting cord 3001 and correspondingly connected limiting holes 3003 provided on each of the plurality of support bars 30. The limiting holes 3003 on the plurality of support bars 30 are arranged relative to each other, and the limiting cord 3001 passes through the limiting holes 3003 on the plurality of support bars 30. The limiting cord 3001 cooperates with the limiting holes 3003 to limit lateral relative displacement and misalignment of the plurality of support bars 30, thereby ensuring that the plurality of support bars 30 remain aligned during use of the rolling curtain assembly. Furthermore, the limiting cord 3001 does not increase the width of the edge of the rolling curtain assembly, thus minimizing its impact on the rolling curtain assembly. The limiting cord 3001 may be in the form of a strip, a filament, or a rope, which is not limited in this embodiment of the present application.

[0171] FIG27 is a left-side structural schematic diagram of the support bars in the projection screen shown in FIG26 . Referring to FIG26 and FIG27 , the connection structure 302 at one end of the support bar 30 includes a C-shaped opening c, and the connection structure 302 at the other end includes a columnar structure j. With this structure, multiple support bars 30 can be connected end to end to form a rolling screen assembly 300. However, in this connection structure 302, two adjacent support bars 30 are prone to offset and misalignment in the transverse direction (perpendicular to the paper in FIG27 , and the transverse direction in FIG26 is the horizontal direction). This may cause the rolling screen assembly to be unable to effectively support the projection screen, thereby reducing the flatness of the projection screen and causing curling of the edges of the projection screen. One solution is to add a limiting structure, such as a limiting screw or a limiting plate, to the edge of the support bar. However, this limiting structure increases the overall width of the rolling screen, affecting its appearance, and affects the smoothness of the rolling screen during curling and unfolding. It may also cause abnormal noise due to wear and tear, and there is also a risk of loosening.

[0172] In this embodiment of the present application, the positioning of the limiting ropes 3001 and the limiting holes 3003 located on the plurality of support bars 30 achieves positioning of the support bars 30, preventing misalignment of the support bars. This provides a simple, stable, and aesthetically pleasing structure without increasing the width of the rolling blind assembly, thereby enhancing the stability of the projection screen provided by this embodiment of the present application. The positioning of the limiting ropes 3001 is extremely advantageous for the rolling blind assembly 300, which is movably connected between adjacent support bars 30.

[0173] It is understandable that for those support bars 30 arranged at a certain interval, or for the embodiment in which the support bars 30 and the projection screen 200 are integrally formed, the limiting ropes 3001 may not be provided, thereby achieving the purpose of simplifying the structure of the projection screen.

[0174] In some implementations, as shown in Figures 12 and 13 , the projection screen 000 may further include a base 500 and a lifting mechanism 600. The reel assembly 100 and the lifting mechanism 600 in the projection screen 000 may both be fixed to the base 500. The lifting mechanism 600 may include a crossbeam 601 that may be fixedly connected to the second end of the projection screen 200. The lifting mechanism 600 may be configured to control the unfolding of the portion of the projection screen 200 wound around the reel assembly 100 via the crossbeam 601.

[0175] The first end of the projection screen 200 is also referred to as the first side, and the second end is also referred to as the second side. These two sides of the projection screen 200 are located opposite each other along the curling direction of the projection screen 200. The crossbeam 601 is fixedly connected to the second end of the projection screen 200 to support the second end of the projection screen 200. When the projection screen 200 needs to be unfolded, the lifting mechanism 600 controls the movement of the crossbeam 601, thereby driving the second side of the projection screen 200 to unfold.

[0176] In some implementations, the rolling curtain assembly 300 further includes at least one tensioning wire 3002, which passes through a plurality of support bars 30 in sequence along the curling direction of the projection screen 200; the tensioning wire 3002 is configured to allow the rolling curtain assembly 300 to be wound and arranged, and to keep the support bars 30 in the rolling curtain assembly 300 in the unfolded state taut.

[0177] Exemplarily, the tensioning wire 3002 includes, but is not limited to, carbon fiber, glass fiber, nylon fiber, and some polymer wires with relatively strong toughness, such as polyvinyl chloride, polypropylene, polypropylene, polystyrene, and the like.

[0178] The diameter of the tensioning wire 3002 can be adaptively designed according to the size of the support bar 30. For example, the embodiment of the present application uses a tensioning wire 3002 of millimeter level, for example, the diameter of the tensioning wire 3002 is 0.5mm-2mm.

[0179] By using tension wires 3002 that run through the multiple support bars 30 to enhance their strength, when the rolling screen assembly 300 is in a rolled-up state, the tension wires 3002 are correspondingly relaxed and no longer provide rigidity. At this point, the support bars 30 and the projection screen 200 are in partial contact, reducing bending strain. When the rolling screen assembly 300 is in an unfolded state, the tension wires 3002 are tightened, keeping the multiple support bars 30 taut, thereby increasing the strength of the projection screen 200.

[0180] In some examples, the tensioning wires 3002 in the projection screen 000 are sequentially fixedly connected to the plurality of support bars 30. The tensioning wires 3002 can be connected to the base 500 and the crossbeam 601 after the lifting mechanism 600 unfolds the projection screen 200. The tensioning wires 3002 can also be disconnected from at least one of the base 500 and the crossbeam 601 before the reel assembly 100 reels the projection screen 200.

[0181] When the projection screen 200 is unfolded, the two ends of the tensioning wire 3002, which is fixedly connected to the multiple support bars 30, can be fixedly connected to the crossbeam 601 and the base 500, respectively, placing the tensioning wire 3002 in a tensioned state. This tensioning wire 3002 acts to tension the projection screen 200, further ensuring the overall flatness of the projection screen 200. When the projection screen 200 needs to be retracted, the tensioning wire 3002 is first disconnected from at least one of the base 500 and the crossbeam 601, thereby relaxing the tensioning wire 3002 and preventing it from curling. For example, elongated holes (not shown) can be provided through each of the multiple support bars 30. The tensioning wire 3002 is then passed through the elongated holes and connected to the multiple support bars 30. This ensures a better appearance on the back of the projection screen 200.

[0182] In addition, the tensioning wire 3002 also serves as the limiting rope 3001. It can be seen that in some examples, the tensioning wire 3002 can be arranged alone without the need to arrange the limiting rope 3001 additionally, which can also serve the purpose of limiting the mutual positioning of multiple support bars 30.

[0183] Along the length direction of the support bars 30 (i.e., the direction parallel to the surface of the projection screen 200), one or more tensioning wires 3002 can be provided, for example, two, three, four, or five evenly arranged. The length direction of the tensioning wires 3002 is perpendicular to the length direction of the multiple support bars 300. For example, when there is one tensioning wire 3002, the tensioning wire 3002 can be provided in the middle of the back of the projection screen 200. The number of tensioning wires 3002 can also be three, with one tensioning wire 3002 provided at each of the two side edges of the back of the projection screen 200 and one tensioning wire 3002 provided in the middle of the back of the projection screen 200.

[0184] In some implementations, referring to FIG. 14 , at least a portion of the plurality of support bars 30 in the projection screen 000 may be solid structures, and / or at least a portion of the plurality of support bars 30 may be hollow structures. For example, the plurality of support bars 30 may all be hollow structures; or the plurality of support bars 30 may all be solid structures; or a portion of the plurality of support bars 30 may be hollow structures, while another portion may be solid structures. This embodiment of the present application does not impose any specific limitations on this.

[0185] As shown in FIG14 , when the support bar 30 is a hollow structure, a reinforcing rib 303 may be provided in the cavity of the support bar 30 to reinforce the support bar 30. For example, the reinforcing rib 303 may be in the shape of an elongated strip, a crescent shape, or other shapes, which are not specifically limited in the present embodiment.

[0186] During the use of the projection screen 200, the projection screen 200 needs to be unfolded and folded many times. In order to reduce the probability of the projection screen 200 having edge curling or unevenness, the present application uses a support bar 30 with thermal expansion characteristics to be arranged on the back of the projection screen 200 and fixedly connected to the back of the projection screen 200, thereby effectively solving the above technical problems.

[0187] When the projection screen 200 is rolled up, in order to prevent the projection screen 200 from being locally deformed, it is necessary to ensure that the projection screen 200 is well fitted with the roll assembly 100. This requires that the support bars 30 have a small thickness h, a small width w, and a large spacing d between two adjacent support bars 30. To this end, it is necessary to ensure that the maximum principal strain ε of the projection screen 200 is principal Less than the failure principal strain [ε] of the projection screen 200.

[0188] When the projection screen 200 is unfolded, it is necessary to ensure that the image projected by the projection host onto the projection screen 200 has a good quality. This requires that the support bars 30 have a large thickness h, the support bars 00 have a large width w, and the spacing d between adjacent support bars 30 is small. To achieve this, it is necessary to ensure that the maximum out-of-plane displacement (max u3) of the projection screen 200 under the combined effects of its own weight and wind pressure (the maximum displacement of the projection screen before and after deformation) is minimized.

[0189] This embodiment of the present application illustrates the influence of the width and thickness of support bars, as well as the distance between adjacent support bars, on the maximum out-of-plane deformation of a projection screen. Please refer to Figure 15, which is a schematic diagram of an unfolded projection screen, illustrating the rectangular cross-section of support bars 30. This illustration uses PET bars as an example.

[0190] The width w of the PET strip, the thickness h of the PET strip, and the distance d between two adjacent PET strips are used as design variables. The maximum out-of-plane displacement max u3 of the projection screen 200 in the unfolded state is minimized as the objective function. The maximum principal strain ε of the projection screen in the rolled state is principal The allowable failure principal strain [ε] less than 200 of the projection screen is the optimization constraint. The optimization problem can be formulated as: find para = [w, d, h] min (max u3) stε principai <[ε]

[0191] In the embodiment of the present application, the roll assembly 100 can be configured as a single roll or multiple rolls. As shown in FIG28 , the roll assembly 100 includes a first roll 101, to which one end of the projection screen 200 and one end of the rolling curtain assembly 300 are both connected. Thus, the projection screen 200 and the rolling curtain assembly 300 can both be rolled up and stored in the same first roll 101. This structure has advantages such as simplicity and compactness.

[0192] For a projection screen in which the projection screen 200 and the rolling curtain assembly 300 are separable, for example, in a solution in which the connecting portion 400 is a magnetic sheet, as shown in FIG29 , the roller assembly 300 includes a second roller 102 and a third roller 103 (the axis of the second roller 102 can be parallel to the axis of the third roller 103). One end of the projection screen 200 is connected to the second roller 102, and one end of the rolling curtain assembly 300 is connected to the third roller 103. In this way, the projection screen 200 and the rolling curtain assembly 300 can be rolled up and stored in two different rollers respectively. This structure can prevent the rolling curtain assembly 300 from damaging the projection screen 200 after the projection screen 200 is rolled up, thereby improving the protection of the projection screen 200.

[0193] On the other hand, an embodiment of the present application further provides a projection device, which includes any of the above-mentioned projection screens 000. The projection device provided by the embodiment of the present application has all the advantages of the above-mentioned projection screens 000.

[0194] The projection device provided in the embodiment of the present application also includes a projection host 001. As shown in FIG30 , the laser projection device includes: a projection screen 000 and a projection host 001.

[0195] Further referring to FIG. 31 , the projection device provided in this embodiment of the present application may further include a storage device 002 for storing the projection host 001 and the projection screen 000. The storage device 002 may have a light-transmitting area 0021 and an opening 0022. The light beam emitted by the projection host 001 can pass through the light-transmitting area 0021, and the lifting mechanism 600 can control the projection screen 200 to pass through the opening 0022 and unfold.

[0196] Thus, when the projection device is not in use, the projection host 001 and the projection screen 000 are stored in the storage device 002, thereby saving space. When the projection device is in use, the lifting mechanism 600 controls the projection screen 200 to unfold, and the projection host 001 projects a light beam onto the projection screen 200, so that the projection screen 200 displays the projection image.

[0197] When the above-described flexible and rigid support bars 30 are used to support the projection screen 200, the flatness of the projection screen 200 can be improved, particularly the flatness of the two transverse edges of the projection screen 200, thereby enhancing the display quality of the image carried by the projection screen 200. When the projection screen 000 is stored in the storage device 002, the flexible and rigid support bars 30 have good bending properties and do not exert significant pressure on the projection screen 200, thereby protecting the projection screen 200 from indentations, extending the service life of the projection screen 000, and reducing the cost of using the laser projection equipment.

[0198] The vertical distance from the center of the light-transmitting area 0021 to the plane of the unfolded projection screen 200 is equal to the product of the projection unit's throw ratio and the width of the display area on the projection screen. The width of the display area refers to the horizontal dimension of the display area. This ensures that the light beam emitted by the projection unit 001 is accurately projected onto the display area of ​​the projection screen 200, ensuring the clarity of the projected image on the projection screen 200.

[0199] Because the throw ratio is a performance parameter of the projection host 001 itself, the throw ratio of the projection host 001 is related to the selected projection host 001. That is, different projection hosts 001 will result in different throw ratios, and consequently, different vertical distances from the center point of the light-transmitting area 0021 to the plane where the unfolded projection screen 200 lies. Therefore, during the actual setup process, the vertical distance from the center point of the light-transmitting area 0021 to the plane where the unfolded projection screen 200 lies is calculated based on the throw ratio of the projection host 001 and the width of the display area. This ensures that the light beam emitted by the projection host 001 is fully projected onto the display area of ​​the projection screen 200.

[0200] For example, the projection host 001 can be an ultra-short-throw projection host. This can shorten the distance between the projector 40 and the projection screen 30, thereby facilitating miniaturization of the projection device. The ultra-short-throw projection host can be a DLP (Digital Light Processing) projection host. Thus, the distance between the projection host 001 and the plane where the projection screen 000 is located is set to a relatively short distance, thereby achieving a miniaturized design of the entire projection device.

[0201] Exemplarily, the projection host 001 may include: a light source, an optical engine, and a lens (not shown in the figure), wherein the light source is used to emit a light beam to the optical engine.

[0202] The optical engine may include a digital micromirror array (DMD) and a driver circuit board electrically connected to the DMD. The driver circuit board in the optical engine is used to provide a drive signal to the DMD. The DMD can then modulate the light beam emitted by the light source based on the drive signal and emit the modulated light beam to the lens. The lens then emits the light beam to the projection screen in the projection screen 000, allowing the projection screen 200 to present a projected image. For example, the lens included in the projection host 001 is an ultra-short-throw projection lens.

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

Claims

1. A projection screen, wherein: The projection screen comprises: a projection screen, a rolling curtain assembly and a roller assembly; The rolling curtain assembly is located on the back of the projection screen, and the first end of the projection screen and the first end of the rolling curtain assembly are both connected to the roller assembly; The rolling curtain assembly includes a plurality of support bars, and the plurality of support bars are arranged in sequence along the curling direction of the projection screen; At least part of the support strips in the rolling curtain assembly have thermal expansion characteristics, and the ratio between the thermal expansion coefficient of the projection screen and the thermal expansion coefficient of at least part of the support strips having the thermal expansion characteristics is less than or equal to a target threshold, and the target threshold is greater than or equal to 1.

2. The projection screen according to claim 1, wherein The projection screen and the support strips with the thermal expansion feature are made of the same material, which includes: the projection screen and at least a portion of the support strips with the thermal expansion feature are both made of polyethylene terephthalate.

3. The projection screen according to claim 1, wherein The projection screen and the support bars are an integrally formed structure.

4. The projection screen according to any one of claims 1 to 3, wherein: At least part of the support strips in the rolling blind assembly has a flexible feature, and at least part of the support strips having the flexible feature is a flexible structure.

5. The projection screen according to claim 4, wherein The flexible structure is obtained by a flexible material and / or an elastic structure.

6. The projection screen according to claim 4, wherein: The support bar having the flexible feature comprises: a support bar main structure and two connecting structures respectively located at both ends of the support bar main structure, at least one of the support bar main structure and the two connecting structures is a flexible structure, and at least one is a hard structure, wherein the hard structure is obtained by hard material and / or rigid structure; The support bar having the flexible feature is connected to the adjacent support bars through the connecting structure.

7. The projection screen according to claim 4, wherein: The plurality of support bars include a plurality of support bar groups, each of the support bar groups includes at least two connected support bars, and each of the support bar groups includes at least one support bar having the flexible feature and at least one rigid support bar; The flexible structure in the support strip having the said flexible characteristics is obtained by arranging flexible materials and / or elastic structures; The rigid support strip is obtained by a rigid material and / or a rigid structural arrangement.

8. The projection screen according to claim 6, wherein: The flexible material includes at least one of silicone, thermoplastic elastomer, thermoplastic polyurethane rubber, polyvinyl chloride modified soft rubber and polyvinyl chloride modified rubber; The hard material includes at least one of polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, carbon fiber, aluminum alloy, polycarbonate and polyvinyl chloride.

9. The projection screen according to claim 5 or 7, wherein: The elastic structure is made of a material having thermal expansion characteristics, so that the ratio of the thermal expansion coefficient of the flexible structure to the thermal expansion coefficient of the projection screen is greater than or equal to a target threshold; And / or, the rigid structure is made of a material having thermal expansion characteristics, so that the ratio of the thermal expansion coefficient of the rigid structure to the thermal expansion coefficient of the projection screen is greater than or equal to a target threshold.

10. The projection screen according to any one of claims 1 to 2, and 4 to 9, wherein: The projection screen further comprises: a connecting portion for connecting the projection screen and the rolling curtain assembly, the connecting portion being fixedly connected to the back surface of the projection screen and a plurality of support bars in the rolling curtain assembly respectively; In a direction perpendicular to the back surface of the projection screen, the thickness of the connecting portion is smaller than the thickness of the projection screen and smaller than the thickness of the supporting bar.

11. The projection screen according to claim 10, wherein: The connecting portion includes: a whole layer of connecting pieces, wherein the orthographic projections of at least some of the plurality of supporting strips on the back of the projection screen are all located within the orthographic projections of the connecting piece on the back of the projection screen; And / or, the connecting portion comprises: a plurality of connecting bars, the plurality of connecting bars supporting at least part of the plurality of supporting bars The strips correspond one to one, and the orthographic projection of each connecting strip on the back of the projection screen is located within the orthographic projection of the corresponding supporting strip on the back of the projection screen.

12. The projection screen of claim 11, wherein: When the connecting portion includes the plurality of connecting strips, the width of each connecting strip is smaller than the width of the corresponding supporting strip, and the orthographic projection of each connecting strip on the back surface of the projection screen is located within the central area of ​​the orthographic projection of the corresponding supporting strip on the back surface of the projection screen.

13. The projection screen according to any one of claims 10 to 12, wherein: The connecting portion is an adhesive layer having adhesive properties or a magnetic structure having magnetism.

14. The projection screen of claim 13, wherein: The connecting part is the magnetic structure, which includes a first magnetic structure and a second magnetic structure. The first magnetic structure is located on the rolling curtain assembly, and the second magnetic structure is located on the surface of the projection screen facing the rolling curtain assembly. The first magnetic structure and the second magnetic structure are attracted to each other.

15. The projection screen of claim 13, wherein: The connecting portion is the magnetic structure, and the magnetic structure includes a third magnetic structure; The support bar includes: a support bar body, and first magnetic particles distributed on at least one of the interior and surface of the support bar body, wherein the first magnetic particles include metal particles, and / or the projection screen includes a screen body and second magnetic particles distributed on at least one of the interior and surface of the screen body, wherein the second magnetic particles include metal particles.

16. The projection screen according to any one of claims 1 to 15, wherein: At least some of the plurality of support bars are solid structures, and / or at least some of the plurality of support bars are hollow structures.

17. The projection screen according to any one of claims 1 to 16, wherein: The rolling curtain assembly further includes at least one tensioning wire, which sequentially passes through the plurality of support bars along the curling direction of the projection screen; The tension wire body is configured to allow the rolling blind assembly to be rolled up and to keep the support bars in the rolling blind assembly in an unfolded state taut.

18. The projection screen according to any one of claims 1 to 17, wherein: The rolling curtain assembly further includes at least one limiting rope, which passes through the plurality of support bars in sequence along the curling direction of the projection screen; The limiting rope is configured to prevent the plurality of support bars from being misaligned in a direction parallel to the projection screen.

19. The projection screen according to any one of claims 1 to 18, wherein: The projection screen further comprises: a base and a lifting mechanism; The drum assembly and the lifting mechanism are both fixed on the base. The lifting mechanism includes a crossbeam fixedly connected to the second end of the projection screen. The lifting mechanism is configured to control the unfolding of the portion of the projection screen wound around the drum through the crossbeam.

20. A projection device, wherein: The projection device includes a projector and a projection screen according to any one of claims 1 to 19.

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