CN115704987A - Projection screen - Google Patents

Abstract

The embodiment of the application discloses a projection screen, and belongs to the technical field of projection. The projection screen includes: the device comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet; the curling mechanism and the lifting mechanism are limited on the base; the first side edge of the curtain sheet is fixedly connected with the curling mechanism, the second side edge of the curtain sheet is fixedly connected with the lifting mechanism, and the first side edge is opposite to the second side edge; the elevating system is formed with first clamping part and second clamping part after the curtain piece expandes, and the part that the curtain piece is close to the third side is spacing at first clamping part, and the part that the curtain piece is close to the fourth side is spacing at the second clamping part. In the embodiment of the application, after the curtain piece is unfolded, the first clamping part and the second clamping part formed by the lifting mechanism respectively clamp the part, close to the fourth side, of the curtain piece close to the third side, and the part, close to the fourth side, of the curtain piece, so that the restraint on the left side and the right side of the curtain piece can be realized, the problem that the curtain piece is folded and curled edges is caused is avoided, and the display effect of a display picture on the curtain piece is improved.

Description

Projection screen

Technical Field

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

Background

With the continuous development of science and technology, projection equipment is more and more applied to people's work and life. At present, a projection device includes a projection host and a projection screen, where a light outlet of the projection host faces the projection screen to emit a projection light beam to the projection screen, and the projection screen is configured to receive the projection light beam to implement display of a picture. Wherein the projection screen is in an expanded state upon receiving the projection beam.

When the projection screen is in an expanded state, the screen included in the projection screen deforms in a direction perpendicular to the left and right sides due to factors such as internal stress and thermal expansion coefficient of the screen, for example, the screen has wrinkles, curled edges, and the like, thereby causing deformation of a display picture projected on the screen.

Disclosure of Invention

The embodiment of the application provides a projection screen, can avoid the curtain piece that projection screen includes to take place fold and turn-up, improves the display effect that shows the picture on the curtain piece. The technical scheme is as follows:

a projection screen, comprising: the device comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet;

the curling mechanism and the lifting mechanism are limited on the base;

the first side edge of the curtain sheet is fixedly connected with the curling mechanism, the second side edge of the curtain sheet is fixedly connected with the lifting mechanism, and the first side edge is opposite to the second side edge;

after the curtain piece expandes elevating system is formed with first clamping part and second clamping part, the part that the curtain piece is close to the third side is spacing to be in first clamping part, the part that the curtain piece is close to the fourth side is spacing to be in the second clamping part, the third side with the fourth side is relative.

The technical scheme provided by the embodiment of the application has the beneficial effects that at least:

in the embodiment of the application, the first clamping part and the second clamping part which are formed by the lifting mechanism after the curtain sheet is unfolded respectively clamp the part of the curtain sheet close to the third side edge and the part of the curtain sheet close to the fourth side edge, so that the restraint of the left side edge and the right side edge of the curtain sheet can be realized, the problem that the curtain sheet is folded and curled is solved, the problem that a display picture is deformed on the curtain sheet is solved, and the display effect is improved.

Drawings

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

Fig. 1 is a schematic expanded structural view of a projection screen provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a curtain provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a curtain provided in an embodiment of the present application;

FIG. 4 is a schematic view of a projection screen according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a retraction of a projection screen according to an embodiment of the present application;

FIG. 6 is a schematic view of an expanded structure of a projection screen according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a retraction of a projection screen according to an embodiment of the present application;

FIG. 8 is a schematic view of an expanded projection screen according to an embodiment of the present disclosure;

FIG. 9 is a schematic view of an expanded projection screen according to an embodiment of the present disclosure;

FIG. 10 is a schematic view of an expanded projection screen according to an embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of an unfolded projection screen according to an embodiment of the present application.

Reference numerals are as follows:

1: a base; 2: a crimping mechanism; 3: a lifting mechanism; 4: a screen sheet; 5: a hold-down mechanism;

11: a protrusion; 12: a guide rail;

31: a first clamping portion; 32: a second clamping portion; 33: a first lifting frame; 34: a second lifting frame; 35: a cross beam; 36: a first curling element; 37: a second crimping member;

331: a first folding bar; 332: a second folding bar; 333: a first support bar; 334: a second support bar;

341: a third folding bar; 342: a fourth folding bar;

41: an optical film; 42: a flexible carrier;

51: a slider; 52: adjusting the screw rod; 53: and a compression roller.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present application more clear, the embodiments of the present application will be further described in detail with reference to the accompanying drawings.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The use of "first," "second," "third," and the like in the description and in the claims of the present application does not denote any order, quantity, or importance, but rather the terms "first," "second," and "third" are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprising" or "comprises" and its equivalents, and does not exclude other elements or items.

Fig. 1 illustrates a schematic structural diagram of a projection screen according to an embodiment of the present application. As shown in fig. 1, the projection screen includes: the device comprises a base 1, a curling mechanism 2, a lifting mechanism 3 and a curtain sheet 4.

Wherein, the base 1 is used for providing a positioning base for the curling mechanism 2 and the lifting mechanism 3 so as to fix the curtain sheet 4 on the curling mechanism 2 and the lifting mechanism 3.

Optionally, as shown in fig. 1, the curling mechanism 2 and the lifting mechanism 3 are both limited on the base 1; the first side of curtain 4 and 2 fixed connection of curling mechanism, the second side and the 3 fixed connection of elevating system of curtain 4, first side and second side are relative.

Wherein, base 1 includes base and holding portion, and the base is located the holding portion, and crimping mechanism 2 and elevating system 3 are all spacing on the base to realize sheltering from crimping mechanism 2 and elevating system 3 through the holding portion, improve projection screen's aesthetic property. In addition, when the screen 4 is stored, the screen is accommodated in the accommodating part, so that the phenomenon of dust falling on the screen 4 is avoided, and meanwhile, the damage of the screen 4 caused by collision of foreign objects and the like is avoided.

The specific structures of the curling mechanism 2 and the lifting mechanism 3 can refer to the related art, which is not limited in the embodiments of the present application. Illustratively, the winding mechanism 2 has a rotatable drum, and a first side of the screen 4 is fixedly connected to the drum. As shown in fig. 1, the lifting mechanism 3 comprises a first lifting frame 33 and a cross beam 35, the first lifting frame 33 is limited on the base 1, the first lifting frame 33 is connected with the cross beam 35, and the second side edge of the curtain sheet 4 is fixedly connected with the cross beam 35. Thus, the curtain sheet 4 can be folded or unfolded by the lifting of the first lifting frame 33 in cooperation with the rotation of the winding drum of the winding mechanism 2. Wherein, the first crane 33 is a scissor-fork type crane, a folding type crane or a telescopic type crane.

When first crane 33 is for cutting fork crane or foldable crane, first crane 33 passes through the rotatable spacing of articulated shaft on base 1, and when first crane 33 was the lift formula crane that contracts, first crane 33 passed through set screw etc. and fixes the spacing on base 1.

In this application embodiment, curtain 4 is the rectangle structure, and the first side and the second side of curtain 4 are the lower side and the last side of curtain 4 promptly, and the display screen on the curtain 4 also can adjust to the rectangle structure to the display area who covers curtain 4 is paved, thereby improves the display effect of display screen on the curtain 4.

In some embodiments, as shown in fig. 2, the curtain sheet 4 includes an optical film 41, and a first side and a second side of the optical film 41 are fixedly connected to the curling mechanism 2 and the lifting mechanism 3, respectively. The optical film 41 is a white plastic screen, a gray plastic screen, a black grid screen, or a flexible PET (Polyethylene Terephthalate) composite film designed with a fresnel structure.

In order to connect the optical film 41 to the curling mechanism 2 and the lifting mechanism 3, the optical film 41 is large in size, which increases the cost. On the other hand, when the optical film 41 is used, the screen is displayed only in the irradiation area corresponding to the projection beam, and thus, in order to reduce the cost of the screen 4, the screen can be displayed by using the optical film 41 having a size as large as the irradiation area corresponding to the projection beam. Illustratively, the optical diaphragm 41 has a size of 1661 mm by 934 mm.

In order to connect the curtain sheet 4 to the curling mechanism 2 and the lifting mechanism 3 and support the optical film 41, in another embodiment, as shown in fig. 3, the curtain sheet 4 includes the optical film 41 and a flexible carrier 42, a back surface of the optical film 41 is fixed on the flexible carrier 42, and a first side and a second side of the flexible carrier 42, which are opposite to each other, are fixedly connected to the curling mechanism 2 and the lifting mechanism 3, respectively.

The flexible carrier 42 is made of a material that is not easily deformed and has a high tensile strength, so as to ensure the curling of the flexible carrier 42 and avoid the deformation of the flexible carrier 42 under the action of an external force. Illustratively, the flexible carrier 42 is a synthetic fabric made of non-deformable polyester yarn with high tensile strength.

Here, the dimension of the optical film 41 in the length direction of the curling mechanism 2 is smaller than the dimension of the flexible carrier 42 in the length direction of the curling mechanism 2, that is, the width of the optical film 41 is smaller than the width of the flexible carrier 42. In this way, when the optical film 41 is bonded to the flexible carrier 42, the edge of the optical film 41 can be prevented from protruding from the flexible carrier 42, and the efficiency of fixing the optical film 41 can be improved.

Of course, as shown in fig. 3, the dimension of the optical film 41 along the length direction of the curling mechanism 2 may also be equal to the dimension of the flexible carrier 42 along the length direction of the curling mechanism 2, that is, the width of the optical film 41 is equal to the width of the flexible carrier 42. This facilitates alignment of the optical film 41 with the edges of the flexible carrier 42 when securing the optical film 41, thereby reducing the size of the curtain 4.

In the embodiment of the present application, when the lifting mechanism 3 cooperates with the curling mechanism 2 to cause the curtain sheet 4 to be unfolded, the left and right sides of the curtain sheet 4 are not constrained, and at this time, the curtain sheet 4 is prone to wrinkle and curl along the direction perpendicular to the left side due to its own factors, so that the display frame on the curtain sheet 4 is deformed, and the display effect is poor. Therefore, as shown in fig. 1, after the curtain sheet 4 is unfolded, the lifting mechanism 3 is formed with a first clamping portion 31 and a second clamping portion 32, a portion of the curtain sheet 4 close to the third side edge is limited at the first clamping portion 31, a portion of the curtain sheet 4 close to the fourth side edge is limited at the second clamping portion 32, and the third side edge is opposite to the fourth side edge.

Wherein, the third side and the fourth side of the curtain sheet 4 are the left side and the right side of the curtain sheet 4. Like this, after curtain 4 expandes, through the spacing of the part that elevating system 3 is close to the third side to curtain 4 and the part that is close to the fourth side, can realize the restraint to the left and right sides limit of curtain 4 to avoid curtain 4 to take place the problem of fold and turn-up, and then avoided on the curtain 4 problem that the display screen warp, improved display effect.

The principle of the first and second clamping portions 31 and 32 clamping the curtain sheet 4 is as follows: the curtain sheet 4 has a certain stiffness, so that, based on the deformation of the curtain sheet 4, such as wrinkles, curls, etc., of the portion close to the third side edge, the portion close to the fourth side edge, after the first clamping portion 31 and the second clamping portion 32 clamp the curtain sheet 4, the deformation region is squeezed, so that an interaction force exists between the portion close to the third side edge of the curtain sheet 4 and the first clamping portion 31 along the thickness direction of the curtain sheet 4, and an interaction force exists between the portion close to the third side edge of the curtain sheet 4 and the first clamping portion 31 along the thickness direction of the curtain sheet 4. When the curtain sheet 4 contracts based on the stress of the curtain sheet 4, a friction force is formed between the part of the curtain sheet 4 close to the third side and the first clamping portion 31, and a friction force is formed between the part of the curtain sheet 4 close to the fourth side and the second clamping portion 32, so that the third side and the fourth side of the curtain sheet 4 are restrained.

In order to further ensure the clamping effect of the first clamping portion 31 and the second clamping portion 32 on the curtain sheet 4, the thickness of the portion of the curtain sheet 4 close to the third side and the thickness of the portion close to the fourth side are both greater than the thickness of the display area of the curtain sheet 4, so as to increase the friction between the portion of the curtain sheet 4 close to the third side and the first clamping portion 31, and increase the friction between the portion of the curtain sheet 4 close to the fourth side and the second clamping portion 32.

Further, after the first clamping portion 31 and the second clamping portion 32 respectively clamp and limit the part of the curtain sheet 4 close to the third side and the part of the curtain sheet 4 close to the fourth side, in order to ensure the stability of clamping the curtain sheet 4, the first clamping portion 31 and the part of the curtain sheet 4 close to the third side can be fixed while clamping, and the second clamping portion 32 and the part of the curtain sheet 4 close to the fourth side can be fixed.

By fixing the first clamping portion 31 and the portion of the curtain sheet 4 close to the third side edge as an example, the first clamping portion 31 and the portion of the curtain sheet 4 close to the third side edge can be fixed by magnetic attraction, or can be fixed by adhesion, and the fixing manner is determined according to the specific structure of the first clamping portion 31.

When the fixing is realized by a magnetic attraction mode, a magnetic coating can be sprayed, adhered and printed on the part, close to the third side, of the curtain sheet 4, or magnetic powder and the like are doped in the manufacturing process of the curtain sheet 4, and meanwhile, the first clamping part 31 is selected as the lifting mechanism 3 of the metal piece, or a metal coating is arranged on the surface, attached to the curtain sheet 4, of the first clamping part 31, so that the fixing is realized through the adsorption between the magnetic powder and the metal piece; metal powder can be sprayed, adhered and printed on the part of the curtain sheet 4 close to the third side edge, or the metal powder is doped in the manufacturing process of the curtain sheet 4, and meanwhile, the first clamping part 31 is selected as the lifting mechanism 3 of the magnetic piece, or a magnetic coating is arranged on the surface of the first clamping part 31 attached to the curtain sheet 4, so that the fixation is realized through the adsorption between the metal powder and the magnetic piece; certainly, a magnetic coating may be sprayed, adhered, and printed on a portion of the curtain sheet 4 near the third side, or magnetic powder is doped in the manufacturing process of the curtain sheet 4, and the first clamping portion 31 is selected as the lifting mechanism 3 of the magnetic member, or the magnetic coating is disposed on the surface of the first clamping portion 31 attached to the curtain sheet 4, so as to achieve fixation through adsorption between the magnetic member and the magnetic member.

Next, the holding and limiting of the curtain sheet 4 will be explained in detail with reference to the specific structure of the lifting mechanism 3.

In the first situation, as shown in fig. 4, the lifting mechanism 3 comprises a first lifting frame 33 and a second lifting frame 34, the second lifting frame 34 is limited on the base 1, the second lifting frame 34 is connected with the cross beam 35, and the first lifting frame 33 and the second lifting frame 34 are respectively positioned at the front side and the rear side of the curtain sheet 4; the part of the curtain sheet 4 which is close to the third side edge and the part which is close to the fourth side edge are clamped between the first lifting frame 33 and the second lifting frame 34 after being unfolded. Therefore, the first lifting frame 33 and the second lifting frame 34 can clamp the part of the curtain sheet 4 close to the third side and the part of the curtain sheet close to the fourth side, namely, the restriction on the left side and the right side of the curtain sheet 4 is realized.

Wherein, first crane 33 and second crane 34 are foldable crane to after first crane 33 and second crane 34 rise, first crane 33 is towards one side of curtain 4, and one side that second crane 34 orientation curtain 4 is the plane, in order to guarantee the centre gripping effect to curtain 4.

Illustratively, as shown in fig. 4, the first crane 33 includes a first folding bar 331, a second folding bar 332 (not shown), a first support bar 333 and a second support bar 334 (not shown), wherein both ends of the first folding bar 331 are rotatably connected to the base 1 and the cross beam 35, respectively, and both ends of the second folding bar 332 are rotatably connected to the base 1 and the cross beam 35, respectively; the base 1 has a guide rail 12, and a first slider 51 and a second slider 51 sliding along the guide rail 12, both ends of a first support rod 333 are respectively rotatably connected with the first folding rod 331 and the first slider 51, and both ends of a second support rod 334 are respectively rotatably connected with the second folding rod 332 and the second slider 51. As described above, when the first slider 51 and the second slider 51 are relatively separated from each other, the first support bar 333 and the second support bar 334 support the first folding bar 331 and the second folding bar 332, respectively, such that the first folding bar 331 and the second folding bar 332 are supported in a linear configuration. As shown in fig. 4, the second crane 34 includes a third folding bar 341 and a fourth folding bar 342, both ends of the third folding bar 341 are rotatably connected to the base 1 and the cross beam 35, respectively, and both ends of the fourth folding bar 342 are rotatably connected to the base 1 and the cross beam 35, respectively. Thus, when the first crane 33 is lifted, the third folding rod 341 and the fourth folding rod 342 can be driven by the cross beam 35 to be supported in a linear structure.

However, the first clamping portion 31 is formed by the first folding bar 331 and the third folding bar 341 having a linear shape, and the second clamping portion 32 is formed by the second folding bar 332 and the fourth folding bar 342 having a linear shape, in such a manner that the first folding bar 331 and the third folding bar 341 having a linear shape overlap each other in the projection of the first folding bar 331 and the third folding bar 341 having a linear shape in the thickness direction of the screen 4, and the fourth folding bar 342 having a linear shape overlap each other in the projection of the second folding bar 332 and the fourth folding bar 342 in the thickness direction of the screen 4.

In a second case, as shown in any one of fig. 5 to 8, the lifting mechanism 3 includes, in addition to the first lifting frame 33, a second lifting frame 34 (not shown) and a first curling element 36; the second lifting frame 34 is limited on the base 1, the second lifting frame 34 is connected with the cross beam 35, and the first lifting frame 33 and the second lifting frame 34 are respectively positioned at the front side and the rear side of the curtain sheet 4; the two ends of the first curling piece 36 are respectively fixedly connected with the curling mechanism 2 and the cross beam 35, the first curling piece 36 is positioned between the first lifting frame 33 and the curtain piece 4 after the curtain piece 4 is unfolded, and the part of the curtain piece 4 close to the third side edge and the part close to the fourth side edge are all clamped between the first curling piece 36 and the second lifting frame 34. Thus, the second crane 34 and the first winding element 36 can clamp the part of the curtain sheet 4 close to the third side and the part close to the fourth side, that is, the left and right sides of the curtain sheet 4 can be restrained.

The structure of the second crane 34 can refer to the above description, and details of the embodiment of the present application are not repeated herein. The first curling piece 36 can be made of metal materials such as stainless steel and aluminum alloy, and can also be made of non-metal materials such as PET, polyimide, cloth and rubber, as long as the flatness of the manufactured curling piece is superior to that of the curtain sheet 4.

One side of the first curling element 36, which faces the curtain sheet 4 after being unfolded, is a plane, so as to ensure the clamping effect of the second lifting frame 34 and the first curling element 36 on the curtain sheet 4. Since the first curling element 36 is attached to the back of the curtain sheet 4 and does not block the image display area on the curtain sheet 4, as shown in fig. 5 or 6, the first curling element 36 is a sheet-like structure, and the first curling element 36 is attached to the entire back of the curtain sheet 4; alternatively, as shown in fig. 7 or fig. 8, the first curling element 36 is a strip structure, and the first curling element 36 is disposed on at least a portion of the back surface of the curtain sheet 4 near the third side edge and a portion near the fourth side edge.

Taking the first curler 36 as an example, the third straight folding bar 341 and the corresponding first curler 36 included in the second crane 34 overlap each other in the projection in the thickness direction of the screen sheet 4, and the fourth straight folding bar 342 and the corresponding first curler 36 included in the second crane 34 overlap each other in the projection in the thickness direction of the screen sheet 4, so that the first clamping portion 31 is formed by the third straight folding bar 341 and the corresponding first curler 36, and the second clamping portion 32 is formed by the fourth straight folding bar 342 and the corresponding first curler 36.

It should be noted that the first curling element 36 and the curtain sheet 4 may be fixed on the same roll, that is, the curling mechanism 2 includes a roll; of course, the first winding member 36 and the curtain sheet 4 can be fixed on different reels, that is, the winding mechanism 2 includes a plurality of reels.

In a third case, as shown in fig. 9, the lifting mechanism 3 includes, in addition to the first crane 33, a plurality of second curling elements 37; two ends of the second curling pieces 37 are fixedly connected with the curling mechanism 2 and the cross beam 35 respectively; the second curly piece 37 and the first crane 33 are located the front and back both sides of curtain 4 respectively after curtain 4 expandes, and the part that curtain 4 is close to the third side, the part centre gripping that is close to the fourth side are between first crane 33 and second curly piece 37. Thus, the first lifting frame 33 and the plurality of second curling pieces 37 can clamp the part of the curtain sheet 4 close to the third side and the part of the curtain sheet close to the fourth side, namely, the restraint of the left side and the right side of the curtain sheet 4 is realized.

The structure of the first lifting frame 33 can refer to the above description, and the material of the second curling element 37 can refer to the material of the first curling element 36 described above, which is not described herein again in this embodiment of the application.

The side of the second curling element 37 which faces the curtain sheet 4 after being unfolded is a plane, so as to ensure the clamping effect of the first lifting frame 33 and the second curling element 37 on the curtain sheet 4. Since the second curling elements 37 are attached to the front surface of the curtain sheet 4, in order to avoid the second curling elements 37 from blocking the picture display area on the curtain sheet 4, as shown in fig. 9, the second curling elements 37 are in a strip shape, the number of the second curling elements 37 is two, and the two second curling elements 37 are respectively attached to the portion of the front surface of the curtain sheet 4 close to the third side edge and the portion of the front surface of the curtain sheet 4 close to the fourth side edge, that is, the second curling elements 37 are disposed on the portion of the front surface of the curtain sheet 4 close to the third side edge and the portion of the front surface of the curtain sheet 4 close to the fourth side edge.

The first folding bar 331 and the corresponding second curling element 37 of the first crane 33 are overlapped in the projection in the thickness direction of the screen 4, and the second folding bar 332 and the corresponding second curling element 37 of the first crane 33 are overlapped in the projection in the thickness direction of the screen 4, so that the first clamping portion 31 is formed by the first folding bar 331 and the corresponding second curling element 37, and the second clamping portion 32 is formed by the second folding bar 332 and the corresponding second curling element 37.

In a fourth case, as shown in fig. 10, the lifting mechanism 3 includes, in addition to the first crane 33, a first curling element 36 and a plurality of second curling elements 37; two ends of the first curling piece 36 are respectively fixedly connected with the curling mechanism 2 and the cross beam 35, and two ends of the second curling pieces 37 are respectively fixedly connected with the curling mechanism 2 and the cross beam 35; after the curtain sheet 4 is unfolded, the first curling piece 36 and the second curling piece 37 are respectively positioned at the front side and the rear side of the curtain sheet 4, and the part of the curtain sheet 4 close to the third side edge and the part close to the fourth side edge are clamped between the first curling piece 36 and the second curling piece 37.

The materials and structures of the first curling element 36 and the second curling element 37 can refer to the first curling element 36 and the second curling element 37 described above, which are not described herein again in this embodiment of the application.

For the above-described first lifting frame 33 and/or the second lifting frame 34 to clamp the part of the curtain sheet 4 close to the third side and the part close to the fourth side, both the first lifting frame 33 and the second lifting frame 34 are folding lifting frames, and for example, the first lifting frame 33 needs to be attached to the back of the curtain sheet 4 after the first folding rod 331 and the second folding rod 332 included in the first lifting frame 33 are lifted, so that the first lifting frame will continuously contact with the back of the curtain sheet 4 when the first folding rod 331 and the second folding rod 332 are lifted, so as to smooth the curtain sheet 4 from the center to the sides when the first lifting frame 33 and/or the second lifting frame 332 are lifted, thereby further ensuring the flatness of the curtain sheet 4 after being lifted.

In the embodiment of the present application, for several clamping structures for the curtain sheet 4 described in the above embodiments, in order to ensure the stability of clamping the curtain sheet 4, as shown in fig. 11, the projection screen further includes a pressing mechanism 5, the pressing mechanism 5 is limited on the base 1, the pressing mechanism 5 contacts with the plurality of second curling elements 37 on the side of the second curling element 37 away from the curtain sheet 4, and the position of the pressing mechanism 5 in the length direction perpendicular to the curling mechanism 2 is adjustable.

Thus, taking the portion of the curtain sheet 4 close to the third side and the portion close to the fourth side clamped between the first lifting frame 33 and the second curling element 37 as an example, the pressing force of the pressing mechanism 5 on the second curling element 37 can be adjusted by adjusting the position of the pressing mechanism 5 in the length direction perpendicular to the curling mechanism 2, so as to reduce the gap between the first lifting frame 33 and the second curling element 37, that is, the gap between the first folding rod 331 and the corresponding second curling element 37, and the gap between the second folding rod 332 and the corresponding second curling element 37, thereby increasing the clamping force on the portion of the curtain sheet 4 close to the third side and the portion close to the fourth side.

Alternatively, as shown in fig. 11, the pressing mechanism 5 includes a slider 51, an adjusting screw 52, and a pressing roller 53; the base 1 is provided with a protrusion 11 and a guide rail 12, a sliding block 51 is slidably limited on the guide rail 12, an adjusting screw 52 is respectively connected with the protrusion 11 and the sliding block 51, the adjusting screw 52 is used for adjusting the distance between the protrusion 11 and the sliding block 51, the end part of a pressure roller 53 is fixedly connected with the sliding block 51, and the pressure roller 53 is in contact with a plurality of second curling pieces 37.

Thus, when the pressing force of the pressing roller 53 on the second curling element 37 needs to be adjusted, only the adjusting screw 52 needs to be rotated to cause the sliding block 51 to slide along the guide rail 12, and then the pressing roller 53 is driven to move along the guide rail 12. The length direction of the guide rail 12 is perpendicular to the plane where the first lifting frame 33 is located when lifted, that is, the included angle between the length direction of the guide rail 12 and the plane where the first lifting frame 33 is located when lifted is 90 degrees. Of course, the included angle between the length direction of the guide rail 12 and the plane where the first lifting and lowering operation is performed may also be 88 degrees, 92 degrees, and the like, which is not limited in the embodiment of the present application.

It should be noted that, when the curtain sheet 4 is clamped by using the first curling member 36, the pressing mechanism 5 may be disposed on a side of the first curling member 36 away from the curtain sheet 4, so that the pressing force applied to the first curling member 36 is adjusted by the pressing mechanism 5 to increase the pressing force applied to the curtain sheet 4 by the first curling member 36 and the second lifting frame 34, or the first curling member 36 and the second curling member 37.

In the embodiment of the application, the first clamping part that forms through elevating system after the curtain piece expandes, the second clamping part is close to the part of third side respectively to the curtain piece, it is spacing to carry out the centre gripping near the part of fourth side, can also realize simultaneously that first clamping part is close to the fixed of the part of third side with the curtain piece through modes such as adsorbing, realize that second clamping part is close to the fixed of the part of fourth side with the curtain piece, in order to realize the restraint to the left and right sides limit of curtain piece, thereby avoid the curtain piece to take place the problem of fold and turn-up, and then avoided the problem that the display screen warp on the curtain piece, and the display effect is improved.

The above description is only illustrative of the embodiments of the present application and is not intended to limit the embodiments of the present application, and any modification, equivalent replacement, or improvement made within the spirit and principle of the embodiments of the present application should be included in the scope of the embodiments of the present application.

Claims (11)

1. A projection screen, comprising: the device comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet;

the curling mechanism and the lifting mechanism are limited on the base;

the first side edge of the curtain sheet is fixedly connected with the curling mechanism, the second side edge of the curtain sheet is fixedly connected with the lifting mechanism, and the first side edge is opposite to the second side edge;

after the curtain piece expandes elevating system is formed with first clamping part and second clamping part, the part that the curtain piece is close to the third side is spacing first clamping part, the part that the curtain piece is close to the fourth side is spacing second clamping part, the third side with the fourth side is relative.

2. The projection screen of claim 1 wherein the lift mechanism comprises a first lift, a second lift, and a cross beam;

the first lifting frame and the second lifting frame are limited on the base, the first lifting frame and the second lifting frame are connected with the cross beam, the second side edge of the curtain sheet is fixedly connected with the cross beam, and the first lifting frame and the second lifting frame are respectively positioned on the front side and the rear side of the curtain sheet;

the part of the curtain piece close to the third side edge and the part of the curtain piece close to the fourth side edge are clamped between the first lifting frame and the second lifting frame after the curtain piece is unfolded.

3. The projection screen of claim 1 wherein the lift mechanism comprises a first lift, a second lift, a first curl, and a cross beam;

the first lifting frame and the second lifting frame are limited on the base, the first lifting frame and the second lifting frame are connected with the cross beam, the second side edge of the curtain sheet is fixedly connected with the cross beam, and the first lifting frame and the second lifting frame are respectively positioned on the front side and the rear side of the curtain sheet;

the two ends of the first curling piece are fixedly connected with the curling mechanism and the cross beam respectively, the first curling piece is located between the first lifting frame and the curtain piece after the curtain piece is unfolded, and the part of the curtain piece close to the third side edge and the part of the curtain piece close to the fourth side edge are clamped between the first curling piece and the second lifting frame.

4. A projection screen according to claim 3 wherein the first curling element is in the form of a sheet.

5. A projection screen as recited in claim 3, wherein the first curling element is in the form of a strip, and wherein the first curling element is disposed on the back of the sheet at least proximate the third side and proximate the fourth side.

6. The projection screen of claim 1 wherein the elevator mechanism comprises a first elevator, a plurality of second curlers, and a cross beam;

the first lifting frame is limited on the base and is connected with the cross beam, the second side edge of the curtain sheet is fixedly connected with the cross beam, and two ends of the second curling pieces are respectively fixedly connected with the curling mechanism and the cross beam;

after the curtain piece is unfolded, the second curling piece and the first lifting frame are respectively positioned at the front side and the rear side of the curtain piece, and the part of the curtain piece close to the third side edge and the part of the curtain piece close to the fourth side edge are clamped between the first lifting frame and the second curling piece.

7. The projection screen of claim 6 wherein the second curling element is in the form of a strip and is disposed on a portion of the front surface of the sheet adjacent the third side and a portion adjacent the fourth side.

8. The projection screen of claim 1 wherein the lift mechanism comprises a first lift frame, a first curl, a plurality of second curls, and a cross-beam;

the first lifting frame is limited on the base, the first lifting frame is connected with the cross beam, and the second side edge of the curtain sheet is fixedly connected with the cross beam;

two ends of the first curling piece are respectively and fixedly connected with the curling mechanism and the cross beam, and two ends of the second curling pieces are respectively and fixedly connected with the curling mechanism and the cross beam;

after the curtain sheet is unfolded, the first curling piece and the second curling piece are respectively positioned at the front side and the rear side of the curtain sheet, and the part of the curtain sheet close to the third side edge and the part of the curtain sheet close to the fourth side edge are clamped between the first curling piece and the second curling piece.

9. A projection screen according to any one of claims 6-8 wherein the projection screen further comprises a hold-down mechanism;

the pressing mechanism is limited on the base, the pressing mechanism is in contact with the second curling pieces on one side, far away from the curtain piece, of the second curling pieces, and the position of the pressing mechanism in the length direction perpendicular to the curling mechanism is adjustable.

10. The projection screen of claim 9 wherein the hold-down mechanism comprises a slider, an adjustment screw, and a hold-down roller;

the base is provided with a protrusion and a guide rail, the sliding block is limited on the guide rail in a sliding mode, the adjusting screw is connected with the protrusion and the sliding block respectively, the adjusting screw is used for adjusting the distance between the protrusion and the sliding block, the end portion of the compression roller is fixedly connected with the sliding block, and the compression roller is in contact with the second curling pieces.

11. The projection screen of claim 10 wherein the length of the rail is perpendicular to the plane in which the first crane is raised.

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