CN214751304U - Lifting projection screen - Google Patents

Abstract

The application provides a lifting projection screen, which comprises a casing, a winding mechanism, a lifting mechanism and a flexible screen, wherein the winding mechanism is arranged on the casing and comprises a first scroll and a second scroll which are mutually spaced; the lifting mechanism comprises a lifting support and a cross beam, the lifting support is arranged on the machine shell and is positioned between the first scroll and the second scroll, the cross beam is connected to the lifting support, and the lifting support is suitable for driving the cross beam to be far away from or close to the machine shell; the flexible screen comprises a first substrate and a second substrate, one ends of the first substrate and the second substrate are connected to the cross beam, the other ends of the first substrate and the second substrate are connected to the first reel and the second reel respectively, the lifting support is located between the first substrate and the second substrate, the first substrate is suitable for being wound on the first reel, and the second substrate is suitable for being wound on the second reel. The application provides a lift projection curtain can make lifting support's atress keep balance, avoids the unilateral atress to produce the slope, has guaranteed the projection effect of flexible screen.

Description

Lifting projection screen

Technical Field

The application relates to the technical field of projection screens, in particular to a lifting projection screen.

Background

The projection screen can improve the display effect of the projector, and is an indispensable part in the projection system. And along with the continuous expansion of projection screen size, lift projection screen receives more and more attention, and it can be with screen rolling to less size when not using to save space, conveniently carry and carry. However, the existing lifting projection screen has a simple structure, and the screen is easy to incline after being lifted, so that the projection display effect is not ideal.

SUMMERY OF THE UTILITY MODEL

An object of the present application is to provide a lifting projection screen to solve the above problems. The present application achieves the above object by the following technical solutions.

The embodiment of the application provides a lifting projection screen, which comprises a shell, a winding mechanism, a lifting mechanism and a flexible screen, wherein the winding mechanism is arranged on the shell and comprises a first scroll and a second scroll which are mutually spaced; the lifting mechanism comprises a lifting support and a cross beam, the lifting support is arranged on the machine shell and is positioned between the first scroll and the second scroll, the cross beam is connected to the lifting support, and the lifting support is suitable for driving the cross beam to be far away from or close to the machine shell; the flexible screen comprises a first substrate and a second substrate, one ends of the first substrate and the second substrate are connected to the cross beam, the other ends of the first substrate and the second substrate are connected to the first reel and the second reel respectively, the lifting support is located between the first substrate and the second substrate, the first substrate is suitable for being wound on the first reel, and the second substrate is suitable for being wound on the second reel.

Compared with the prior art, the lifting projection screen provided by the embodiment of the application comprises a winding mechanism, a lifting assembly and a flexible screen, wherein the lifting assembly comprises a lifting support and a cross beam, the winding mechanism comprises a first scroll and a second scroll, the flexible screen comprises a first substrate and a second substrate, the lifting support is arranged between the first scroll and the second scroll, the lifting support, the first substrate and the second substrate are all connected to the cross beam, and the lifting support is arranged between the first substrate and the second substrate, so that the stress of the lifting support is kept balanced under the action of the first substrate and the second substrate, the phenomenon that the stress on one side is inclined is avoided, and the projection effect of the flexible screen is ensured; simultaneously, first base plate and second base plate can shelter from lifting support, have improved the outward appearance uniformity of lift projection curtain.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a lifting projection screen in a storage state according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a lifting projection screen in an expanded state according to an embodiment of the present application.

Fig. 3 is an exploded view of the lifting projection screen provided in the embodiment of the present application.

Fig. 4 is a schematic structural diagram of a lifting mechanism and a winding mechanism in a lifting projection screen provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a flexible screen and a winding mechanism in a lifting projection screen provided in an embodiment of the present application.

Fig. 6 is a schematic structural diagram of a cross beam in the lifting projection screen provided in the embodiment of the present application.

Fig. 7 is a schematic structural diagram of a winding mechanism in a lifting projection screen provided in an embodiment of the present application.

Fig. 8 is a sectional view of the winding mechanism in fig. 7 in the direction a-a.

Fig. 9 is an exploded view of a winding mechanism in the lifting projection screen according to the embodiment of the present application.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

The existing lifting projection screen comprises a floor-pulling type projection screen, a wall-mounted projection screen and the like, but the tension provided by the projection screens is insufficient, so that the screen is easy to warp, wrinkle and the like, the display effect is unsatisfactory, especially for an ultra-short-focus projection screen, the ultra-short-focus projection screen has high requirements on the smoothness of the screen, and the existing projection screen cannot meet the requirement of ultra-short-focus projection.

In view of the above, after a great deal of research, the inventor proposes a lifting projection screen, which realizes automatic lifting of a flexible screen through a winding mechanism and a lifting mechanism, and solves the problem of uneven surface when an ultra-short focus projection screen is manufactured as a lifting screen by adopting a mode of high tension such as a pull wire and the like; meanwhile, the design of double reels consisting of the first reel and the second reel is adopted, so that the front and rear tension borne by the lifting bracket is kept balanced, and the problem of inclination of unilateral stretching is avoided; on the other hand, the first winding shaft is connected with the transmission shaft through the tension control mechanism, the problems of synchronous coordination and speed matching of the lifting mechanism and the winding mechanism are solved, and the display effect and the reliability of the lifting projection screen are improved.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1 to fig. 3, the lifting projection screen 100 of the present embodiment includes a housing 110, a winding mechanism 120, a lifting mechanism 130 and a flexible screen 140, wherein the winding mechanism 120 is disposed on the housing 110, the winding mechanism 120 includes a first winding shaft 121 and a second winding shaft 122, and the first winding shaft 121 and the second winding shaft 122 are spaced from each other; the lifting mechanism 130 includes a lifting bracket 131 and a beam 132, the lifting bracket 131 is disposed on the housing 110 and located between the first reel 121 and the second reel 122, the beam 132 is connected to the lifting bracket 131, and the lifting bracket 131 is adapted to drive the beam 132 to move away from or close to the housing 110; the flexible screen 140 includes a first substrate 141 and a second substrate 142, one end of each of the first substrate 141 and the second substrate 142 is connected to the beam 132, the other end of each of the first substrate 141 and the second substrate 142 is connected to the first reel 121 and the second reel 122, respectively, the lifting bracket 131 is located between the first substrate 141 and the second substrate 142, the first substrate 141 is adapted to be wound around the first reel 121, and the second substrate 142 is adapted to be wound around the second reel 122.

In the lifting projection screen 100 provided in this embodiment, the winding mechanism 120 includes the first reel 121 and the second reel 122, the lifting bracket 131 is disposed between the first reel 121 and the second reel 122, the lifting bracket 131, the first substrate 141 and the second substrate 142 are all connected to the cross beam 132, and the lifting bracket 131 is located between the first substrate 141 and the second substrate 142, so that the stress of the lifting bracket 131 is kept balanced under the action of the first substrate 141 and the second substrate 142, thereby preventing the lifting bracket 131 from tilting due to the stress on one side, and ensuring the display effect of the flexible screen 140; meanwhile, the first substrate 141 and the second substrate 142 can also shield the part of the lifting bracket 131 extending out of the casing 110, thereby improving the appearance consistency of the lifting projection screen 100.

In this embodiment, the first substrate 141 and the second substrate 142 may be connected at a local position to form an integrated structure. Of course, the first substrate 141 and the second substrate 142 may not be connected, as long as both the first substrate 141 and the second substrate 142 are connected to the beam 132.

The housing 110 may include a housing 111 and a frame 112, the housing 111 may be a rectangular housing 111, the housing 111 is provided with a mounting cavity 113 and a strip-shaped groove 114 communicated with the mounting cavity 113, the winding mechanism 120 is mounted in the mounting cavity 113, and the lifting bracket 131 and the flexible screen 140 may extend out of the housing 110 from the strip-shaped groove 114. The outline of the beam 132 can be adapted to the strip-shaped groove 114, and when the lifting bracket 131 is accommodated in the casing 110, the beam 132 can be embedded in the strip-shaped groove 114; alternatively, the outline of the cross beam 132 may be larger than the strip-shaped groove 114, and when the lifting bracket 131 is received in the casing 110, the cross beam 132 may abut against the outer surface of the casing 110. In one embodiment, the extending direction of the cross beam 132 and the axial directions of the first and second reels 121 and 122 are all consistent with the length direction of the housing 110.

The frame 112 is installed in the housing 111, the frame 112 may include a first supporting plate 115, a second supporting plate 116 and a bottom plate 117, the first supporting plate 115 and the second supporting plate 116 are oppositely disposed and are respectively located at two sides of the length direction of the casing 110; the base plate 117 is mounted to the bottom of the housing 111 and is connected between the first and second support plates 115 and 116.

The shaft diameters of the first and second reels 121 and 122 should be not less than the minimum rolling diameter of the flexible screen 140 (i.e., the minimum diameter at which the flexible screen 140 is not plastically deformed), and the shaft diameters of the first and second reels 121 and 122 should not be too large to occupy too much volume. The first and second reels 121 and 122 may be parallel to each other and arranged side by side, both ends of the first reel 121 may be rotatably connected to the first and second support plates 115 and 116, respectively, and both ends of the second reel 122 may be rotatably connected to the first and second support plates 115 and 116, respectively. The first reel 121 and the second reel 122 adopt the same or similar size design and rotation parameters, so that the front and back stress of the lifting bracket 131 is basically consistent, and the inclination caused by the stress on one side is avoided.

In some embodiments, the lifting mechanism 130 may further include a lifting driving base 133, the lifting driving base 133 is disposed in the housing 110, the lifting bracket 131 is connected between the lifting driving base 133 and the cross beam 132, and the lifting driving base 133 drives the lifting bracket 131 to be selectively received in the housing 110 or extend outward from the housing 110. The lifting driving base 133 is used for realizing electric lifting of the flexible screen 140, and when not in use, the lifting support 131 can be accommodated in the housing 110, so that the lifting projection screen 100 has a simpler appearance and is convenient to carry.

In this embodiment, the lifting driving base 133 is installed on the bottom plate 117 and located vertically below the first reel 121 and the second reel 122, the bottom end of the lifting bracket 131 is connected to the lifting driving base 133, and the other end of the lifting bracket penetrates through between the first reel 121 and the second reel 122.

In some embodiments, the first substrate 141 and the second substrate 142 are both elastic substrates, that is, the first substrate 141 and the second substrate 142 both have elasticity, so that the first substrate 141 and the second substrate 142 can be tensioned when being stretched, thereby ensuring a projection display effect and solving the problem that a conventional hard screen is difficult to stretch.

Illustratively, the first substrate 141 and the second substrate 142 are made of a non-shrinkable base material having an elastic modulus ranging from 1000MPa to 4000MPa, such as nylon cloth, polyester cloth, and the like. The thicknesses of the first substrate 141 and the second substrate 142 are both less than or equal to 0.5mm, and the widths of the first substrate 141 and the second substrate 142 are greater than or equal to 2mm, and practical tests show that when the thicknesses of the first substrate 141 and the second substrate 142 exceed 0.5mm, the overall rigidity is too high, abnormal phenomena such as wave warping and the like easily occur, and the stretching is difficult to flatten.

In some embodiments, the flexible screen 140 further includes a plurality of screen films 143, and the plurality of screen films 143 are disposed on a side of the first substrate 141 facing away from the second substrate 142. The side of the first substrate 141 facing away from the second substrate 142 may refer to a side of the first substrate 141 facing away from the second substrate 142 after the first substrate 141 and the second substrate 142 are unfolded. The flexible screen 140 is formed by splicing a plurality of screen films 143, which mainly considers that a single screen (e.g., a fresnel screen) is difficult to have a large size (e.g., 100 inches or more), and therefore, the plurality of screen films 143 need to be laid on the first substrate 141 meeting the requirement of the large size according to the requirement of the projection area, so that the finally formed flexible screen 140 can meet the requirement of the large size specification.

In this embodiment, the screen film 143 includes, but is not limited to, a fresnel screen, a wire grid screen, a white plastic screen, a glass fiber screen, and the like, and the connection manner of the screen film 143 and the first substrate 141 may include bonding, sewing, thermocompression bonding, and the like. Illustratively, the screen film 143 is adhesively connected to the first substrate 141 by an adhesive layer, and the thickness of the adhesive layer is not too thick, so as to prevent the screen film 143 from being separated from the first substrate 141 after a large number of winding times. It should be noted that the thinner the thickness of the flexible screen 140, the more suitable it is for winding. The first substrate 141 and the second substrate 142 may have the same or similar shape and size, and illustratively, the sum of the thicknesses of the screen film 143 and the first substrate 141 is less than or equal to 0.5mm, and when the sum of the thicknesses of the two exceeds 0.5mm, the winding radius is too large, the screen film is not easy to wind, and problems such as embossing are easily generated.

In other embodiments, a side of the second substrate 142 facing away from the first substrate 141 may also be provided with a screen film 143, so that both the first substrate 141 and the second substrate 142 can be used for projection display, and a person skilled in the art may choose to only lay the screen film 143 on the first substrate 141 or the second substrate 142, or lay the screen film 143 on the first substrate 141 and the second substrate 142 at the same time, according to actual needs.

Referring to fig. 3 and 4 together, in some embodiments, the lifting driving base 133 may include a screw mechanism 134 and a chassis 135, and the lifting bracket 131 includes a first bar 1311, a second bar 1312, a third bar 1313 and a fourth bar 1314, the first bar 1311 and the second bar 1312 are crossed and hinged with each other, and the third bar 1313 and the fourth bar 1314 are crossed and hinged with each other; the two ends of the first rod 1311 are hinged to the chassis 135 and the third rod 1313, respectively, and the third rod 1313 is hinged to the cross beam 132; two ends of the second rod 1312 are respectively hinged to the screw rod mechanism 134 and the fourth rod 1314, the screw rod mechanism 134 is suitable for driving the second rod 1312 to slide, and the fourth rod 1314 is hinged to the cross beam 132 and can slide relative to the cross beam 132. Therefore, one end of the second rod 1312 can be pushed to slide by the screw rod mechanism 134, and the horizontal sliding of the second rod 1312 can be converted into the lifting and lowering movement of the cross beam 132 in the vertical direction by the scissor structure formed by the first rod 1311, the second rod 1312, the third rod 1313 and the fourth rod 1314. Meanwhile, the scissor-type structure formed by the first rod 1311, the second rod 1312, the third rod 1313 and the fourth rod 1314 can realize a larger lifting height, and meets the requirement of a large-size screen.

In this embodiment, the screw mechanism 134 and the chassis 135 are both mounted on the bottom plate 117, the chassis 135 and the bottom plate 117 may be integrally formed, and the chassis 135 may be provided with a first hinge seat (not numbered), and the first rod 1311 is hinged to the first hinge seat, so as to realize the hinge of the first rod 1311 and the chassis 135. The lead screw mechanism 134 may include a lead screw 1341 and a lead screw nut 1342, an extending direction of the lead screw 1341 is identical to an extending direction of the cross beam 132, the lead screw nut 1342 is screwed to the lead screw 1341, and the lead screw nut 1342 may be provided with a second hinge seat (not numbered), and the second rod 1312 is hinged to the second hinge seat.

The lifting driving base 133 can further include a lifting driving motor 136, the lead screw 1341 is connected to the lifting driving motor 136 through a coupler, the lifting driving motor 136 is suitable for driving the lead screw 1341 to rotate, the lead screw 1341 drives the lead screw nut 1342 and a second rod 1312 above the lead screw nut 1342 to slide synchronously, and then the automatic lifting of the lifting support 131 can be realized.

In this embodiment, first bar 1311, second bar 1312, third bar 1313, and fourth bar 1314 are each generally an elongated plate-like structure. The lifting bracket 131 may further include a first reinforcement bar 1315 and a second reinforcement bar 1316, the first reinforcement bar 1315 and the second reinforcement bar 1316 intersecting and articulating with each other; the first reinforcing bar 1315 is hinged at both ends thereof to the first bar 1311 and the fourth bar 1314, respectively, and the second reinforcing bar 1316 is hinged at both ends thereof to the second bar 1312 and the third bar 1313, respectively, to play a role of reinforcing the lifting bracket 131.

In other embodiments, the lifting bracket 131 may include only the first bar 1311 and the second bar 1312; alternatively, the lifting bracket 131 may further include other rod members such as a fifth rod, a sixth rod, and the like, and those skilled in the art may select that the lifting bracket 131 is composed of one or more groups of X-shaped brackets according to the requirement of lifting height.

In some embodiments, second rod 1312 may include first plate 1317 and second plate 1318, first plate 1317 and second plate 1318 being disposed opposite and connected to each other, and first rod 1311 being hingedly coupled between first plate 1317 and second plate 1318. In the embodiment, the middle of the second rod 1312 is hollowed to form a first support plate 1317 and a second support plate 1318 which are arranged oppositely, the first support plate 1317 and the second support plate 1318 can be connected with each other through a sandwich connector, the first rod 1311 is arranged between the first support plate 1317 and the second support plate 1318 in a penetrating mode, the overall thickness (not more than 20mm) of the first rod 1311 and the second rod 1312 can be reduced, and the overall weight of the lifting bracket 131 is reduced; meanwhile, the first rod 1311 is only hollowed out, and the original thickness can be maintained, so that the bending rigidity can be ensured.

Likewise, third rod 1313 may include a third leg (not numbered) and a fourth leg (not numbered) disposed opposite and connected to each other, fourth rod 1314 may be hinged at a central location between the third and fourth legs, fourth rod 1314 may be hinged at an end between first and second legs 1317, 1318, and first rod 1311 may be hinged at an end between the third and fourth legs.

In some embodiments, the number of the lifting brackets 131 includes two, and the two lifting brackets 131 are respectively located at both ends of the extending direction of the cross beam 132 to support the cross beam 132 more smoothly, so as to prevent the cross beam 132 from being inclined.

In this embodiment, the number of the lifting driving bases 133 also includes two, so as to respectively drive the two lifting brackets 131 to lift. The two lifting brackets 131 may be symmetrical to each other about a center line of the cross beam 132, wherein the center line of the cross beam 132 is perpendicular to the extending direction of the cross beam 132. Further, the connection point of the second rod 1312 to the lift drive base 133 is located inside the lift drive base 133 with respect to the connection point of the first rod 1311 to the lift drive base 133, and the connection point of the fourth rod 1314 to the cross member 132 is located inside the cross member 132 with respect to the connection point of the third rod 1313 to the cross member 132, so as to provide sufficient sliding space for the second rod 1312 and the fourth rod 1314.

In other embodiments, the number of the lifting brackets 131 may be only one or more than two. When the number of the lifting brackets 131 is one, the lifting mechanism 130 may be disposed centrally with respect to the cross beam 132; when the number of the lifting brackets 131 is two or more, the lifting brackets may be arranged at intervals along the extending direction of the cross beam 132.

Referring to fig. 5, in some embodiments, the lifting mechanism 130 may further include a pulling wire 137, the pulling wire 137 is inserted into the first base plate 141, one end of the pulling wire 137 is connected to the cross beam 132, the other end of the pulling wire 137 is connected to the first reel 121, and the pulling wire 137 is always in a tensioned state to tension the first base plate 141.

Specifically, one end of the pulling wire 137 is connected to the first reel 121, and the other end of the pulling wire 137 penetrates into the first substrate 141 from a certain position, penetrates out after a certain distance is separated, penetrates into the first substrate 141 again after a certain distance is separated, and penetrates out again after a certain distance is separated, so that the pulling wire 137 can be connected to the beam 132 after the penetrating and penetrating out are repeated for multiple times. The pull wire 137 can be wound around the first reel 121 along with the first substrate 141, and the pull wire 137 is always in a tensioned state in the process of being wound around the first reel 121 and in the process of being extended from the first reel 121, so as to provide tension for the first substrate 141, and avoid abnormal phenomena such as vertical stripes and the like caused by the fact that the first substrate 141 is only subjected to vertical tension.

In this embodiment, the pulling wire 137 avoids using an elastic wire which is easy to deform, and the pulling wire 137 is preferably a high-strength and high-toughness wire material, and should have a large elastic modulus, and preferably does not deform significantly when stretched. Illustratively, pull string 137 may be a twine, fishing line, or steel wire, among others.

In this embodiment, when the screen film 143 (see fig. 3) is disposed on the first substrate 141, the screen film 143 may cover the pull string 137, and the color of the pull string 137 may be set optionally. Of course, the drawing wire 137 may be inserted into the screen film 143 while being inserted into the first substrate 141, and at this time, the color of the drawing wire 137 is the same as or similar to the color of the screen film 143.

In this embodiment, the second substrate 142 may also be inserted with a pulling wire 137, and one end of the pulling wire 137 is connected to the second winding shaft 122 and the other end is connected to the cross beam 132, so that the second substrate 142 may be tensioned.

In some embodiments, the pulling wire 137 may include a first wire body 1371 and a second wire body 1372, the first wire body 1371 and the second wire body 1372 are respectively inserted into two opposite sides of the first substrate 141, and the first wire body 1371 and the second wire body 1372 are respectively inserted into two opposite sides of the first substrate 141, so as to provide tension to the two sides of the first substrate 141, and further improve the tensioning effect of the first substrate 141.

In this embodiment, the first line body 1371 and the second line body 1372 are disposed as close to the edge of the first substrate 141 as possible, for example, the distances between the first line body 1371 and the second line body 1372 and the edge of the first substrate 141 are both less than 2 mm. The first and second wires 1371 and 1372 may be respectively formed by winding a plurality of wires to improve the strength of the first and second wires 1371 and 1372 and prevent a breakage during use.

In other embodiments, the pull wire 137 may further include a third wire body, a fourth wire body, and the like, and the first wire body 1371, the second wire body 1372, the third wire body, and the fourth wire body may be arranged at intervals along the extending direction of the cross beam 132, and a person skilled in the art may select the number of the wire bodies according to actual requirements, which is not described herein again.

In some embodiments, the elevating projection screen 100 may further include a roller (not shown), such as a nip roller, a tension roller, etc., disposed in the extending direction of the first substrate 141 and/or the second substrate 142 (see fig. 3 in detail) to better control the flattening effect of the first substrate 141 and/or the second substrate 142.

Referring to fig. 5 and 6, in some embodiments, the cross beam 132 may include a rod portion 1321, a first locking member 1322 and a second locking member (not shown), the first locking member 1322 and the second locking member are respectively disposed at two ends of the rod portion 1321 in the length direction and are both in threaded connection with the rod portion 1321, the first wire 1371 is connected to the first locking member 1322 and is adapted to be wound around the first locking member 1322, and the first locking member 1322 is used for adjusting the tension of the first wire 1371; the second wire 1372 is connected to the second locking member and adapted to be wound around the second locking member, and the second locking member is used to adjust the tension of the second wire 1372.

In this embodiment, the first locking member 1322 and the second locking member 1323 may be both hanging rings, one end of which is used for connecting the pulling wire 137, and the other end of which is screwed with the rod portion 1321. Taking the first locking member 1322 as an example, during use, the first locking member 1322 can be rotated in a forward direction, and the first wire body 1371 is continuously wound around the first locking member 1322, so that the tension of the first locking member 1322 can be increased; when the first locking member 1322 is rotated in the reverse direction, the first wire body 1371 gradually extends from the first locking member 1322, and the first wire body 1371 becomes slack, that is, the tension of the first wire body 1371 is reduced, so that the tension of the first wire body 1371 is adjustable.

The cross member 132 may further include a first end cap 1323 and a second end cap 1329, the first end cap 1323 and the second end cap 1329 are detachably covered on the axial ends of the body portion 1321, respectively, and the first locking member 1322 is received in the first end cap 1323 and the second locking member is received in the second end cap 1329 to conceal the first locking member 1322 and the second locking member.

The farther the fixing point of the wire 137 to the first reel 121 and the fixing point of the wire 137 to the cross member 132 are from the side edge of the first base plate 141, the greater the horizontal component force of the wire 137 toward the outside of the side edge of the first base plate 141, and the easier the tightening effect is achieved. For example, the distance between the fixing points of the first and second wires 1371 and 1372 and the cross beam 132 and the side edge of the first substrate 141, and the distance between the fixing points of the first and second wires 1371 and 1372 and the first reel 121 and the side edge of the first substrate 141 are greater than a set value, which may be 20 mm.

In some embodiments, the cross member 132 may further include a first mounting surface 1324 and a second mounting surface (not shown), the first mounting surface 1324 and the second mounting surface face away from each other, the first substrate 141 is fixed to the first mounting surface 1324, and the second substrate 1429 (see fig. 3 for details) is fixed to the second mounting surface, so that the acting force exerted on the cross member 132 by the first substrate 141 and the second substrate 142 can be kept balanced, and the first substrate 141, the second substrate 142 and the cross member 132 can be ensured to have sufficient contact areas through surface-to-surface contact connection, thereby improving connection stability.

In this embodiment, the first mounting surface 1324 and the second mounting surface are both located on the rod body portion 1321, the first mounting surface 1324 and the second mounting surface are both planar, and the first mounting surface 1324 and the second mounting surface are parallel to each other.

In some embodiments, the cross beam 132 may further include a third mounting surface 1325, the third mounting surface 1325 is connected between the first mounting surface 1324 and the second mounting surface, and the lifting bracket 131 (see fig. 4 in detail) is connected to the third mounting surface 1325, so that the lifting bracket 131 is located between the first substrate 141 and the second substrate 142 (see fig. 3 in detail), and the stress of the lifting bracket 131 is balanced by the first substrate 141 and the second substrate 142.

In this embodiment, the third mounting surface 1325 is located on the rod portion 1321, the third mounting surface 1325 is a plane, and the third mounting surface 1325 may be perpendicular to the first mounting surface 1324 and the second mounting surface.

Referring to fig. 4 and fig. 6, in the present embodiment, the cross beam 132 may further include a sliding rail 1326, a third hinge seat 1327 and a fourth hinge seat 1328, the sliding rail 1326 is fixedly installed on the rod body portion 1321 and is consistent with the extending direction of the rod body portion 1321, the fourth hinge seat 1328 is slidably installed on the sliding rail 1326, the fourth rod 1314 is hinged to the fourth hinge seat 1328, so as to realize the hinge connection between the fourth rod 1314 and the cross beam 132, and the fourth rod 1314 can slide relative to the cross beam 132. The third hinge seat 1327 is fixedly connected to the rod portion 1321, and the third rod 1313 is hinged to the third hinge seat 1327, so as to realize the hinged connection between the third rod 1313 and the cross beam 132.

Referring to fig. 3, 8 and 9, in some embodiments, the winding mechanism 120 may further include a winding driving assembly 123, the winding driving assembly 123 includes a transmission shaft 124 and a tension control mechanism 125, the first winding shaft 121 is connected to the transmission shaft 124 via the tension control mechanism 125, the first winding shaft 121 is rotatable relative to the tension control mechanism 125, and the tension control mechanism 125 is adapted to apply a friction force to the first winding shaft 121, which is adjustable, so as to solve the problem of synchronization and speed matching between the lifting mechanism 130 and the winding mechanism 120.

It should be noted that, the lifting mechanism 130 drives the reel to rotate through the flexible screen 140 during the lifting process, and the lifting mechanism 130 usually lifts at a non-constant speed, so that the unwinding speed of the flexible screen 140 is not constant, and the rotation speed of the winding mechanism 120 is generally constant, so that there is a rotation speed difference between the winding mechanism 120 and the reel, and it needs to be connected through the tension control mechanism 125. In the related art, the method for coordinating the rotating speeds of the winding mechanism 120 and the lifting mechanism 130 through software is complex, cannot avoid errors, and is easy to burn out a driving motor. The embodiment connects the first reel 121 to the transmission shaft 124 through the tension control mechanism 125, and the friction between the tension control mechanism 125 and the first reel 121 is adjustable, so that the tension control mechanism 125 and the first reel 121 are not rigidly connected, that is, the first reel 121 and the transmission shaft 124 are not rigidly connected, thereby allowing the situation that the rotating speeds of the first reel 121 and the transmission shaft 124 are not matched to occur, and being simple, stable, error-free and free from the risk of burning out the motor.

In this embodiment, the number of the winding driving assemblies 123 may include two sets, and the two sets of winding driving assemblies 123 are respectively disposed at two axial ends of the first reel 121 to provide sufficient driving force for the first reel 121, and to avoid torsion of the reel generated by single-side driving of the first reel 121, so as to solve the problem of inconsistent tension at two sides of the first substrate 141. Of course, in other embodiments, the first winding shaft 121 may also be driven by a single side, and only one side of the first winding shaft 121 is connected to the winding driving assembly 123.

The winding driving assembly 123 may further include a winding driving motor 126, and the winding driving motor 126 may be coupled to the driving shaft 124 through a coupling to drive the driving shaft 124 to rotate. The winding driving component 123 is provided with a winding driving motor 126, and can be conveniently controlled. In other embodiments, the transmission shaft 124 may also transmit power from an external mechanism through a gear, belt, or light transmission.

It should be noted that the second reel 122 is also connected to the winding driving assembly 123, and the second reel 122 may be connected to one or two winding driving assemblies 123, which may specifically refer to the first reel 121, and is not described herein again.

In some embodiments, the tension control mechanism 125 includes a connecting sleeve 1251 and a compression portion 1252, the connecting sleeve 1251 is connected to the transmission shaft 124 and is provided with a first contact surface 1253, the compression portion 1252 is sleeved on the outer periphery of the connecting sleeve 1251 and is provided with a second contact surface 1254, the compression portion 1252 is rotatable relative to the connecting sleeve 1251 to move the second contact surface 1254 closer to or away from the first contact surface 1253, and the first roller 121 is at least partially positioned between the first contact surface 1253 and the second contact surface 1254. When the second contact surface 1254 is close to the first contact surface 1253, the friction force between the tension control mechanism 125 and the first winding shaft 121 increases, and when the second contact surface 1254 is far away from the first contact surface 1253, the friction force between the tension control mechanism 125 and the first winding shaft 121 decreases, and may even be zero, so that the friction force is adjustable, and the tension control mechanism 125 does not need additional power input, and the structural design is ingenious.

In this embodiment, first contact surface 1253 and second contact surface 1254 may be selectively coated with layers of materials having different coefficients of friction. Taking the first winding shaft 121 as an example, when the first winding shaft 121 and the winding driving assembly 123 have a difference in rotation speed, the first winding shaft 121, the first contact surface 1253 and the second contact surface 1254 generate sliding friction, at this time, the friction force determines the torque of the first winding shaft 121, and the acting force of the lifting mechanism 130 is converted into the torque of the first winding shaft 121 through the tension of the first substrate 141, so that the effect of controlling the tension of the first substrate 141 through the friction force is achieved. The magnitude of the torque of the first reel 121 is related to only the friction coefficient of the contact surfaces and the pressing force between the first reel 121 and the first and second contact surfaces 1253 and 1254, and the pressing force between the first reel 121 and the first and second contact surfaces 1253 and 1254 can be adjusted by rotating the pressing portion 1252 regardless of the rotation speed of the first reel 121, thereby controlling the tension value of the first substrate 141 so that the first substrate 141 can be always kept in a tensioned state.

In some embodiments, the compression portion 1252 may include a compression ring 1255 and a compression nut 1256, the compression ring 1255 is disposed around the outer periphery of the connection sleeve 1251 and is slidable relative to the connection sleeve 1251, the compression ring 1255 is provided with a second contact surface 1254; the compression nut 1256 bears against the compression ring 1255 on the side facing away from the second contact surface 1254 and is screwed to the connecting sleeve 1251. Thus, the compression nut 1256 can be rotated in a forward direction to bring the second contact surface 1254 close to the first roller 121, and the entire operation can be facilitated by rotating the compression nut 1256 in a reverse direction to disengage the second contact surface 1254 from the first roller 121.

In this embodiment, the first winding shaft 121 may include a cylinder 1211, an end cap 1212, and a connection ring 1213, the connection ring 1213 is located between the end cap 1212 and the cylinder 1211, the connection ring 1213 is disposed around the cylinder 1211 and is fixedly connected to the cylinder 1211, the end cap 1212 is disposed at one end of the connection ring 1213 and is fixedly connected to the connection ring 1213, the first substrate 141 is connected to the cylinder 1211, and the connection ring 1213 may limit the first substrate 141 when the first substrate 141 is wound in the cylinder 1211, so as to ensure that the side surface of the first substrate 141 is flush. The end cap 1212 is disposed around the connecting sleeve 1251 and between the first contact surface 1253 and the second contact surface 1254.

Taking the first substrate 141 and the first reel 121 as an example, the control principle of the tension control mechanism 125 provided in this embodiment is as follows: when the first substrate 141 is lifted, the first reel 121 rotates along with the first substrate, the winding driving motor 126 is controlled to rotate at a rotation speed lower than that of the first reel 121 (including non-rotation or reverse rotation), at this time, there is a rotation speed difference between the two sides of the tension control mechanism 125, the first reel 121 can rotate only by overcoming a preset torque, and since the friction force applied by the tension control mechanism 125 is kept constant, and further the preset torque is constant, the tension force of the first substrate 141 in the unwinding process is stable and controllable. The position of the first reel 121 is fixed after the first substrate 141 is unfolded to the fixed position, and the first reel 121 can rotate unless an external force overcomes a predetermined torque, so that the first substrate 141 has a holding force in a static state without a vibration phenomenon. When the first substrate 141 needs to be wound, the winding driving motor 126 is controlled to wind the first substrate at a higher speed than the lifting driving motor 136 (see fig. 4 for details), and at this time, a speed difference exists between two sides of the tension control mechanism 125, so that the first substrate 141 is always wound with the same torque by the friction force applied by the tension control mechanism 125, the winding process is stable, and the first substrate 141 can be ensured to be wound on the first reel 121 all the time.

In other embodiments, the tension control mechanism 125 may be controlled by magnetic powder, electromagnetic force, etc., and the magnitude of the frictional force applied by the tension control mechanism 125 to the first winding shaft 121 may be adjusted in real time by adjusting the magnitude of the input current. For example, the transmission shaft 124 is sleeved on the outer circumference of the first winding shaft 121 and is in clearance fit with the outer circumference of the first winding shaft 121. The tension control mechanism 125 may include a coil mounted to the driving shaft 124 and magnetic powder filled in a gap between the driving shaft 124 and the first bobbin 121. When the coil is not electrified, the transmission shaft 124 and the first reel 121 are not connected and can idle; after the coil is electrified, the magnetic powder is arranged along the magnetic flux direction under the action of magnetic force to form a magnetic powder chain, the transmission shaft 124 and the first winding shaft 121 are connected together, the transmission shaft 124 and the first winding shaft 121 can rotate together, the maximum torque which can be transmitted by the transmission shaft 124 and the first winding shaft 121 can be changed by adjusting the connecting force of the magnetic powder chain by adjusting the current of the coil, and therefore tension control of the first substrate 141 is achieved.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (15)

1. An elevating projection screen, comprising:

a housing;

the winding mechanism is arranged on the shell and comprises a first reel and a second reel which are spaced from each other;

the lifting mechanism comprises a lifting support and a cross beam, the lifting support is arranged on the machine shell and is positioned between the first reel and the second reel, the cross beam is connected to the lifting support, and the lifting support is suitable for driving the cross beam to be far away from or close to the machine shell; and

the flexible screen comprises a first substrate and a second substrate, wherein one end of the first substrate and one end of the second substrate are connected to the cross beam, the other end of the first substrate and the other end of the second substrate are connected to the first reel and the second reel respectively, the lifting support is located between the first substrate and the second substrate, the first substrate is suitable for being wound on the first reel, and the second substrate is suitable for being wound on the second reel.

2. The elevating projection screen of claim 1, wherein the cross-beam includes a first mounting surface and a second mounting surface, the first mounting surface and the second mounting surface facing away from each other, the first base plate being secured to the first mounting surface, the second base plate being secured to the second mounting surface.

3. The elevating projection screen of claim 2, wherein the cross-beam further comprises a third mounting surface, the third mounting surface connected between the first mounting surface and the second mounting surface, the elevating bracket connected to the third mounting surface.

4. The elevating projection screen of claim 1, wherein the elevating mechanism further comprises an elevating drive base disposed within the housing, the elevating bracket connected between the elevating drive base and the beam, the elevating drive base driving the elevating bracket to be selectively received within the housing or to extend outward from the housing.

5. The elevating projection screen of claim 4, wherein the elevating drive base comprises a screw mechanism and a chassis, the elevating support comprises a first rod, a second rod, a third rod and a fourth rod, the first rod and the second rod are hinged to each other, and the third rod and the fourth rod are hinged to each other; two ends of the first rod are respectively hinged to the chassis and the third rod, and the third rod is hinged to the cross beam; two ends of the second rod are respectively hinged to the screw rod mechanism and the fourth rod, the screw rod mechanism is suitable for driving the second rod to slide, and the fourth rod is hinged to the cross beam and can slide relative to the cross beam.

6. The elevating projection screen of claim 5, wherein the second rod comprises a first plate and a second plate, the first plate and the second plate being disposed opposite one another and connected to one another, the first rod being hingedly connected between the first plate and the second plate.

7. The elevating projection screen of claim 1, wherein the elevating mechanism further comprises a pulling wire, the pulling wire is inserted into the first base plate, one end of the pulling wire is connected to the cross beam, the other end of the pulling wire is connected to the first reel, and the pulling wire is under tension.

8. The elevating projection screen of claim 7, wherein the pull wire comprises a first wire and a second wire, the first wire and the second wire being respectively inserted on opposite sides of the first base plate.

9. The elevating projection screen of claim 8, wherein the cross member comprises a body portion, a first locking member and a second locking member, the first locking member and the second locking member are respectively disposed at two ends of the body portion in a length direction and are both in threaded connection with the body portion, and the first wire is connected to the first locking member and is adapted to be wound around the first locking member; the second line body is connected to the second locking piece and is suitable for being wound on the second locking piece.

10. The elevating projection screen of claim 1, wherein the take-up mechanism further comprises a take-up drive assembly, the take-up drive assembly comprising a drive shaft and a tension control mechanism, the first spool being coupled to the drive shaft via the tension control mechanism, the first spool being rotatable relative to the tension control mechanism, the tension control mechanism being adapted to apply a frictional force to the first spool, the frictional force being adjustable.

11. The elevating projection screen of claim 10, wherein the tension control mechanism comprises a connecting sleeve and a pressing portion, the connecting sleeve is connected to the transmission shaft and has a first contact surface, the pressing portion is sleeved on the outer circumference of the connecting sleeve and has a second contact surface, the pressing portion is rotatable relative to the connecting sleeve to move the second contact surface closer to or away from the first contact surface, and the first roller is at least partially located between the first contact surface and the second contact surface.

12. The lifting projection screen of claim 11, wherein the compression part comprises a compression ring and a compression nut, the compression ring is sleeved on the periphery of the connecting shaft sleeve and is provided with the second contact surface; the compression nut is abutted against one side of the compression ring, which is far away from the second contact surface, and is in threaded connection with the connecting shaft sleeve.

13. The elevating projection screen of any one of claims 1-12, wherein the number of elevating brackets comprises two, and the two elevating brackets are respectively located at two ends of the beam in the extending direction.

14. The elevating projection screen of any one of claims 1-12, wherein the flexible screen further comprises a plurality of screen membranes, the plurality of screen membranes being disposed on a side of the first substrate facing away from the second substrate.

15. The elevating projection screen of any one of claims 1-12, wherein the first substrate and the second substrate are both flexible substrates.

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