CN115598912A

CN115598912A - Projection screen

Info

Publication number: CN115598912A
Application number: CN202211339691.9A
Authority: CN
Inventors: 陈友才; 杨长明
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-10-28
Filing date: 2022-10-28
Publication date: 2023-01-13

Abstract

The application discloses projection screen belongs to the projection display field. The projection screen includes: the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips. The supporting strips fixedly connected with the back of the curtain sheet are arranged along the curling direction of the curtain sheet, and the ratio of the thermal expansion coefficient of the curtain sheet to the thermal expansion coefficient of the supporting strips is smaller than or equal to a target threshold value, namely the thermal expansion coefficient of the curtain sheet is close to that of the supporting strips. Thus, when the projection screen is in a high-temperature environment, the degree of thermal expansion of the screen sheet in the projection screen is close to that of the support strip. And after the curtain piece is connected with the support bar, the curtain piece is heated the inflation back, and is less to the pressure that a plurality of support bars were exerted, and it is less to make the support bar produce the degree of bucking deformation, and then makes a plurality of support bars can carry out effectual support to the curtain piece to reduced the curtain piece and after expanding many times and packing up, the probability of the bad phenomenon of edge curl or inside unevenness takes place for the curtain piece.

Description

Projection screen

Technical Field

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

Background

With the development of science and technology, laser projection systems are increasingly applied to the work and life of people. At present, laser projection systems mainly include: the projection device is used for projecting a projection beam to the projection screen so as to display a projection picture on the projection screen.

Projection screens generally include: the curtain comprises a curtain sheet, a curling mechanism and a lifting mechanism, wherein one side of the curtain sheet is connected with the curling mechanism, and the other side of the curtain sheet is connected with the lifting mechanism. The curtain sheet can be retracted through the control of the curling mechanism, and can be unfolded through the control of the lifting mechanism.

However, after the screen is expanded and retracted for many times, the screen is prone to have undesirable phenomena of edge curling or internal unevenness, which causes undesirable problems such as distortion of the projection picture presented on the screen, and further causes poor display effect of the projection picture on the screen.

Disclosure of Invention

The embodiment of the application provides a projection screen. The problem of the relatively poor display effect of the projection picture that shows on the projection screen of prior art can be solved, technical scheme is as follows:

in one aspect, a projection screen is provided, the projection screen comprising:

the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips;

the winding drum is fixedly connected with the first side edge of the curtain sheet;

at least part of the curtain sheet can be wound on the winding drum in a curling mode, and the front face of the curtain sheet is used for displaying a projection picture;

the support bars are fixedly connected with the back surface of the curtain sheet and are arranged along the curling direction of the curtain sheet;

wherein a ratio between a coefficient of thermal expansion of the curtain sheet and a coefficient of thermal expansion of the support strip is less than or equal to a target threshold.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

a projection screen, may comprise: the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips. The supporting strips fixedly connected with the back of the curtain sheet are arranged along the curling direction of the curtain sheet, and the ratio of the thermal expansion coefficient of the curtain sheet to the thermal expansion coefficient of the supporting strips is smaller than or equal to a target threshold value, namely the thermal expansion coefficient of the curtain sheet is close to that of the supporting strips. Thus, when the projection screen is in an environment with higher temperature, the thermal expansion degree of the curtain sheets in the projection screen is close to the thermal expansion degree of the supporting strips. And after the curtain piece is connected with the support strip, the pressure that the curtain piece was exerted after the thermal expansion is received to the curtain piece is less, makes the support strip produce the degree of bucking deformation less, and then makes a plurality of support strips can carry out effectual support to the curtain piece to reduce the curtain piece and expand many times and pack up the back, the probability that the curtain piece takes place the bad phenomenon of marginal turn-up or inside unevenness.

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 an effect diagram of a linear cursor image presented when a curtain shown in the related art is not thermally expanded;

fig. 2 is an effect diagram of a linear cursor image presented when a curtain sheet shown in the related art is expanded by heat;

FIG. 3 is a rear view of a projection screen provided in an embodiment of the present application;

FIG. 4 is a side view of a projection screen provided in an embodiment of the present application;

FIG. 5 is an effect diagram of a linear cursor image presented by the curtain shown in FIG. 3 when the curtain is not thermally expanded;

FIG. 6 is an effect diagram of a linear cursor image presented when the curtain shown in FIG. 3 expands due to heat;

FIG. 7 is a side view of another projection screen provided in embodiments of the present application;

FIG. 8 is a side view of yet another projection screen provided by an embodiment of the present application;

FIG. 9 is a side view of yet another projection screen provided in an embodiment of the present application;

FIG. 10 is a side view of a projection screen provided in accordance with another embodiment of the present application;

FIG. 11 is a side view of yet another projection screen provided in accordance with another embodiment of the present application;

fig. 12 is a schematic structural diagram of a projection screen provided in an embodiment of the present application;

FIG. 13 is a schematic view of a tension cord attached to a brace bar according to an embodiment of the present application;

FIG. 14 is a schematic view of a support strip and a curtain sheet according to an embodiment of the present disclosure;

FIG. 15 is a schematic view of the curtain as it is deployed;

fig. 16 is a schematic structural diagram of a laser projection apparatus provided in an embodiment of the present application;

fig. 17 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application.

Specific embodiments of the present application have been shown by way of example in the drawings and will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

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

In the related art, in order to prevent the curtain sheet 10 from being easily curled at the edge or uneven inside after the curtain sheet in the projection screen is unfolded and folded by the lifting mechanism and the curling mechanism for many times, a plurality of supporting strips 20 may be disposed on the back surface of the curtain sheet 10. However, the support strip 20 has a thermal/wet expansion coefficient much smaller than that of the curtain sheet 10, for example, when the support strip 20 is a carbon fiber sheet, the thermal expansion coefficient of the carbon fiber sheet is usually 0.57 microstrain/degree, and the thermal expansion coefficient of the curtain sheet 10 is usually 60 microstrain/degree. Thus, when the projection screen 00 is in a high temperature environment, the degree of thermal expansion of the curtain sheet 10 in the projection screen 00 is much larger than that of the carbon fiber sheet. When the curtain sheet 10 is connected to the carbon fiber sheets, the curtain sheet 10 expands due to heat and applies pressure to the plurality of carbon fiber sheets with smaller expansion degree, so that the carbon fiber sheets buckle and deform, resulting in poor flatness of the front surface of the curtain sheet 10 connected to the carbon fiber sheets. The projection image displayed on the front surface of the screen 10 still has the problem of distortion, etc., and the display effect of the projection image on the screen 10 is poor. However, in order to reduce the degree of deformation of the curtain sheet when the curtain sheet 10 and the carbon fiber sheet thermally expand, the distance between each two adjacent carbon fiber sheets is generally set to be large. However, this in turn results in the ability to improve the flatness of only a small portion of the sheet 10, i.e., limits the effect of the carbon fiber sheet on improving the overall strength of the sheet 10.

For example, referring to fig. 1 and fig. 2, fig. 1 is an effect diagram of a linear cursor image presented when a curtain shown in the related art is not thermally expanded, and fig. 2 is an effect diagram of a linear cursor image presented when a curtain shown in the related art is thermally expanded. When the projection screen 00 is not expanded by heat, each support strip 20 can effectively support the screen 10, so as to ensure that the front surface of the screen 10 has good flatness, and the cursor image 30 displayed on the screen 10 has no obvious distortion. When the projection screen 00 expands due to heat, each support strip 20 is driven by the thermal expansion of the screen 10 to form a buckling deformation, which results in poor flatness of the front surface of the screen 10 and significant distortion of the cursor image 30 displayed on the screen 10.

Referring to fig. 3 and 4, fig. 3 is a rear view of a projection screen provided in an embodiment of the present application, and fig. 4 is a side view of the projection screen provided in the embodiment of the present application. Projection screen 000 may include: a roll 100, a curtain sheet 200, and a plurality of support strips 300.

The roll 100 of the projection screen 000 can be fixedly connected to the first side of the curtain sheet 200.

At least a portion of the curtain sheet 200 in the projection screen 000 can be wound on the winding drum 100 in a winding manner, and the front surface of the curtain sheet 200 can be used for displaying a projection picture.

The plurality of supporting strips 300 in the projection screen 000 may be all fixedly connected with the back of the curtain sheet 200, and the plurality of supporting strips 300 may be arranged along the curling direction of the curtain sheet 200.

The ratio of the thermal expansion coefficient of the curtain sheet 200 in the projection screen 000 to the thermal expansion coefficient of the supporting bars 300 fixed on the back of the curtain sheet 200 may be less than or equal to a target threshold. For example, when the ratio between the thermal expansion coefficient of the curtain sheet 200 and the thermal expansion coefficient of the supporting strip 300 is smaller than or equal to the target threshold, the value of the target threshold may be 3. It should be noted that, in practical applications, different target thresholds may be selected according to the size of the curtain sheet 200 and the diameter of the roll 100 for rolling the curtain sheet 200, which is not specifically limited in the embodiments of the present application.

In the embodiment of the present application, the supporting bars 300 fixedly connected to the back surface of the curtain sheet 200 are arranged along the curling direction of the curtain sheet 200, and the ratio between the thermal expansion coefficient of the curtain sheet 200 and the thermal expansion coefficient of the supporting bars 300 is less than or equal to the target threshold, i.e. the thermal expansion coefficient of the curtain sheet 200 is close to the thermal expansion coefficient of the supporting bars 300. Thus, when the projection screen 000 is in a high temperature environment, the curtain sheet 200 in the projection screen 000 expands to a similar extent to the support bars 300. And after the curtain piece 200 is connected with the support strip 300, the pressure applied to the plurality of support strips 300 is smaller after the curtain piece 200 is heated and expanded, so that the buckling deformation degree of the support strips 300 is smaller, and further the plurality of support strips 300 can effectively support the curtain piece 200, thereby reducing the probability that the curtain piece 200 has edge curling or the bad phenomenon of internal unevenness after the curtain piece 200 is unfolded and folded for many times. In this application, the thickness of brace bar 300 may be greater than the thickness of curtain sheet 200 in a direction perpendicular to the back of curtain sheet 200. Thus, the structural strength and the bending rigidity of the support bar 300 are ensured to be greater than those of the curtain sheet 200, so that the support bar 300 can effectively support the curtain sheet 200. And then can guarantee that the positive roughness of curtain 200 is better, effectual the reduction curtain 200 appears on the positive projection picture the probability of bad problems such as distortion etc. appear.

For example, referring to fig. 5 and fig. 6, fig. 5 is an effect diagram of a linear cursor image displayed when the curtain sheet shown in fig. 3 is not thermally expanded, and fig. 6 is an effect diagram of a linear cursor image displayed when the curtain sheet shown in fig. 3 is thermally expanded. When the curtain sheet 200 is not expanded by heat, each support strip 300 can effectively support the curtain sheet 200, so as to ensure that the front surface of the curtain sheet 200 has good flatness. A long cursor image A1 is projected on the screen 200 in a direction perpendicular to the longitudinal direction of the stay strip 300, and the long cursor image A1 is not significantly distorted. When curtain 200 and support strip 300 are heated/wet inflation, the buckling deformation degree of curtain 200 and the buckling deformation degree of support strip 300 are close to each other to guarantee that support strip 300 can play effectual effect of supporting to curtain 200, and then can guarantee that the positive roughness of curtain 200 is better. A long cursor image A1 is projected on the screen 200 in a direction perpendicular to the longitudinal direction of the stay strip 300, and the long cursor image A1 is also not significantly distorted.

It should be noted that, as shown in fig. 3, the thermal expansion coefficient of the curtain sheet 200 is close to the thermal expansion coefficient of the supporting bars 300. Therefore, the interval between every two adjacent supporting bars 300 of the plurality of supporting bars 300 provided on the back surface of the curtain sheet 200 can be set smaller. Thus, the flatness of most of the area of the curtain sheet 200 can be effectively improved.

In summary, an embodiment of the present application provides a projection screen, which may include: the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips. The supporting strips fixedly connected with the back of the curtain sheet are arranged along the curling direction of the curtain sheet, and the ratio of the thermal expansion coefficient of the curtain sheet to the thermal expansion coefficient of the supporting strips is smaller than or equal to a target threshold value, namely the thermal expansion coefficient of the curtain sheet is close to that of the supporting strips. Thus, when the projection screen is in a high-temperature environment, the degree of thermal expansion of the screen sheet in the projection screen is close to that of the support strip. And after the curtain piece is connected with the support bar, the curtain piece is heated the inflation back, and is less to the pressure that a plurality of support bars were exerted, and it is less to make the support bar produce the degree of bucking deformation, and then makes a plurality of support bars can carry out effectual support to the curtain piece to reduced the curtain piece and after expanding many times and packing up, the probability of the bad phenomenon of edge curl or inside unevenness takes place for the curtain piece.

Optionally, please refer to fig. 7, and fig. 7 is a side view of another projection screen provided in the embodiment of the present application. The curtain sheet 200 and the supporting bars 300 in the projection screen 000 may be an integrally formed structure. In this case, the curtain sheet 200 and the support strip 300 may be simultaneously formed through one injection molding process. Thus, the connection process between the curtain sheet 200 and the support bars 300 in the projection screen 000 can be effectively simplified, and the connection precision between the curtain sheet 200 and the support bars 300 can be effectively ensured.

In the embodiment of the present application, please refer to fig. 8, and fig. 8 is a side view of another projection screen provided in the embodiment of the present application. Projection screen 000 may also include: and a connecting part 400 between the curtain sheet 200 and the support strip 300, wherein the connecting part 400 can be fixedly connected with the back of the curtain sheet 200 and the plurality of support strips 300 respectively. In a direction perpendicular to the back surface of the curtain sheet 200, the thickness of the connection portion 400 may be less than the thickness of the curtain sheet 200, and may be less than the thickness of the support bar 300. In this case, the plurality of support bars 300 are fixed to the rear surface of the curtain sheet 200 by providing the connection part 400 between the curtain sheet 200 and the support bars 300. Thus, the curtain sheet 200 and the support strip 300 can be assembled together through the connecting process after being separately manufactured, and the respective organization states, performances and the like of the curtain sheet 200 and the support strip 300 can not be changed. In addition, make the thickness of connecting portion 400 be less than the thickness of curtain piece 200, and be less than the thickness of support bar 300, guarantee that curtain piece 200, connecting portion 400 and support bar 300 three when being in the higher environment of temperature, even connecting portion 400 takes place thermal expansion, and the influence that produces curtain piece 200 is also less. Thereby ensuring the flatness of the curtain sheet 200.

Alternatively, the connection part 400 in the projection screen 000 may include: the connecting piece 401 of the whole layer, and the orthographic projection of at least part of the supporting strips 300 in the plurality of supporting strips 300 on the back surface of the curtain sheet 200 can be positioned in the orthographic projection of the connecting piece 401 on the back surface of the curtain sheet 200.

And/or, the connection part 400 may include: a plurality of connecting bars 402, the plurality of connecting bars 402 may correspond one-to-one with at least some support bars 300 of the plurality of support bars 300. The orthographic projection of each connecting strip 402 on the back side of the curtain sheet 200 may be within the orthographic projection of the corresponding supporting strip 300 on the back side of the curtain sheet 200.

As can be seen from the above, there are various alternative implementations of the structural form of the connecting portion 400 respectively connected to the curtain sheet 200 and the plurality of supporting bars 300, and the embodiment of the present application is schematically illustrated by taking the following three alternative implementations as examples:

in a first alternative implementation, as shown in fig. 8, the connection part 400 may include: the connecting sheet 401 disposed in the whole layer, and the orthographic projections of the plurality of supporting bars 300 on the back surface of the curtain sheet 200, which are located on the back surface of the curtain sheet 200, can be located in the orthographic projection of the connecting sheet 401 on the back surface of the curtain sheet 200. In this case, the support bars 300 are fixed on the back of the curtain sheet 200 through the connecting sheet 401 arranged in the whole layer, so that the contact area between the support bars 300 and the curtain sheet 200 is large, and the structural strength and the bending rigidity of the whole area in the curtain sheet 200 are effectively increased. Furthermore, after the screen sheet 200 is unfolded, the probability of the undesirable phenomenon that the edge of the screen sheet 200 is curled or the interior of the screen sheet 200 is uneven is low, and the good display effect of the projection picture on the screen sheet 200 is ensured. In addition, the connecting sheet 401 arranged in the whole layer is directly connected with the back surface of the curtain sheet 200, and then the supporting bars 300 are fixed on the side, away from the curtain sheet 200, of the connecting sheet 401 arranged in the whole layer. Thus, the assembly process of the support bars 300 and the curtain sheet 200 is simple, and the assembly accuracy of the plurality of support bars 300 and the curtain sheet 200 can be ensured. Note that the orthographic projection of the entire layer of connecting sheet 401 on the back surface of the curtain sheet 200 is located in the region of the back surface of the curtain sheet 200.

Referring to fig. 9, fig. 9 is a side view of another projection screen according to an embodiment of the present disclosure. The connection part 400 may include: a plurality of connecting strips 402, the plurality of connecting strips 402 may correspond one-to-one with the plurality of supporting strips 300 located in the back of the curtain sheet 200. The orthographic projection of each connecting strip 402 on the back side of the curtain sheet 200 may be within the orthographic projection of the corresponding support strip 300 on the back side of the curtain sheet 200. In this case, by providing the plurality of connection bars 402 to be connected to the plurality of support bars 300 in a one-to-one correspondence, the assembly flexibility of each support bar 300 to the rear surface of the curtain sheet 200 is ensured, and the overall weight of the connection portion 400 is reduced, so that the overall weight of the projection screen 000 is small.

Referring to fig. 10, fig. 10 is a side view of a projection screen according to another embodiment of the present application. The connection part 400 includes: a full layer of connecting tabs 401 and a plurality of connecting strips 402. Among them, the orthographic projection of a part of support bars 300 on the back of curtain sheet 200 in the plurality of support bars 300 on the back side of curtain sheet 200 may be located within the orthographic projection of connecting sheet 401 on the back of curtain sheet 200. The plurality of connecting bars 402 correspond to another portion of the plurality of support bars 300 one-to-one, and an orthographic projection of each connecting bar 402 on the back side of the curtain sheet 200 may be located within an orthographic projection of the corresponding support bar 300 on the back side of the curtain sheet 200. Illustratively, as shown in fig. 10, the back side of the curtain sheet 200 includes: a first area A2 and a second area A3 adjacently disposed along the curling direction of the curtain sheet 200, the entire layer of connection strips 401 in the connection portion 400 may be disposed in the second area A3 in the back surface of the curtain sheet 200, and the plurality of connection strips 402 are disposed in the first area A2 in the back surface of the curtain sheet 200. After the curtain sheet 200 is retracted, typically, a portion of the curtain sheet 200 is wound onto the roll 100 and another portion is unwound from the roll 100. The first area A2 may be an area where the back surface of the curtain sheet 200 wound on the roll 100 is located, and the second area A3 may be an area where the back surface of the curtain sheet 200 not wound on the roll 100 is located. Thus, when the curtain sheet 200 needs to be retracted, the portion corresponding to the curtain sheet 200 connected with the connecting strips 402 can be easily curled on the winding drum 100, and the overall structural strength and bending rigidity of the portion corresponding to the curtain sheet 200 connected with the connecting strip 401 in the whole layer are good, so that the flatness of the curtain sheet 200 in the portion is good.

In the embodiment of the present application, as shown in fig. 9, when the connection part 400 includes a plurality of connection bars 402, a width of each connection bar 402 may be smaller than a width of the corresponding support bar 300. And the orthographic projection of each connecting strip 402 on the back side of the curtain sheet 200 may be located within the central area of the orthographic projection of the corresponding support strip 300 on the back side of the curtain sheet 200. In this case, by setting the width of each connecting bar 402 to be smaller than the width of the corresponding supporting bar 300. In this way, while the support strip 300 is used to support the curtain sheet 200, the contact area between each support strip 300 and the curtain sheet 200 is small, so that the curtain sheet 200 can be easily wound on the winding drum 100 when being retracted. In addition, by arranging the orthographic projection of each connecting strip 402 on the back of the curtain sheet 200 to be positioned in the central area of the orthographic projection of the corresponding supporting strip 300 on the back of the curtain sheet 200, the supporting force exerted by the supporting strips 300 on the area, connected with the plurality of supporting strips 300, on the back of the curtain sheet 200 is distributed uniformly, and the integral flatness of the curtain sheet 200 is further ensured. For example, as shown in fig. 10, a plurality of supporting bars 300 and a plurality of connecting bars 402 are disposed in the first area A2 on the back surface of the curtain sheet 200, and the width of each connecting bar 402 may be smaller than the width of the corresponding supporting bar 300. The first area A2 may be an area where the back surface of the curtain sheet 200 wound on the winding drum 100 is located, and the second area A3 may be an area where the back surface of the curtain sheet 200 not wound on the winding drum 100 is located.

Alternatively, the connection portions 400 respectively connected to the back surface of the curtain sheet 200 and the supporting bar 300 may be an adhesive layer having adhesiveness or a magnetic sheet 400a having magnetism. In this case, the plurality of supporting bars 300 may be fixed in the rear surface of the curtain sheet 200 by being adhered using an adhesive layer, or may be fixed in the rear surface of the curtain sheet 200 by being magnetically coupled using the magnetic sheet 400a. For example, the adhesive layer may be any one of a double-sided tape, a liquid glue, or a foam adhesive, which is not specifically limited in this embodiment of the application.

In the embodiment of the present application, please refer to fig. 11, fig. 11 is a side view of another projection screen provided in another embodiment of the present application. When the connection part 400 may be a magnetic sheet 400a having magnetism, the support bar 300 may include: the support strip comprises a support strip body a1 and metal particles a2 distributed in the support strip body a 1. In this case, by integrating the metal particles a2 in the supporting bar body a1, and using the magnetic sheet 400a having magnetism as the connecting portion 400. Thus, the supporting bars 300 can be attached to the back surface of the curtain sheet 200 through the magnetic sheets 400a. The side of the magnetic sheet 400a departing from the support strip 300 can be bonded to the back of the curtain sheet 200, or particles such as magnetic powder (not shown in the figure) can be integrated into the curtain sheet 200, and the magnetic sheet 400a is adsorbed on the back of the curtain sheet 200.

Optionally, please refer to fig. 12 and 13, in which fig. 12 is a schematic structural diagram of a projection screen according to an embodiment of the present application, and fig. 13 is a schematic connection diagram of a tension rope and a support bar according to an embodiment of the present application. Projection screen 000 may also include: a base 500, a lift mechanism 600, and a tension cord 700. The winding drum 100 and the lifting mechanism 600 in the projection screen 000 may be both fixed on the base 500, the lifting mechanism 600 may include a beam 601, the beam 601 may be fixedly connected to the second side edge of the curtain sheet 200, and the lifting mechanism 600 may be configured to: the cross beam 601 controls the partial unwinding of the curtain sheet 200 wound on the winding drum 100. The first side and the second side of the curtain sheet 200 may be two sides of the curtain sheet 200 that are oppositely disposed along the curling direction of the curtain sheet 200. The tension ropes 700 in the projection screen 000 may be respectively fixedly connected to the plurality of supporting bars 300 in sequence, and the tension ropes 700 may be respectively connected to the base 500 and the cross member 601 after the lifting mechanism 600 unfolds the curtain sheet 200. The tensioning cord 700 can also be disconnected from at least one of the base 500 and the cross member 601 before the roll 100 curls the curtain 200. In this case, when the curtain sheet 200 needs to be unfolded, the lifting mechanism 600 can control the cross beam 601 to move, and then the cross beam 601 drives the second side edge of the curtain sheet 200 to move, so as to realize the unfolding of the curtain sheet 200.

In addition, after the curtain sheet 200 is unfolded, both end portions of the tension rope 700 fixedly connected to the plurality of stay bars 300 can be fixedly connected to the cross member 601 and the base 500, respectively, and the tension rope 700 is in a tensioned state. So that the tensioning rope 700 can tension the curtain sheet 200, and the overall flatness of the curtain sheet 200 is further ensured. When the curtain sheet 200 needs to be retracted, the tensioning cord 700 is first disconnected from at least one of the base 500 and the cross member 601 to place the tensioning cord 700 in a relaxed state without affecting the curling of the curtain sheet 200. For example, a plurality of support bars 300 may be provided with a plurality of elongated holes (not shown) through each support bar 300, and the tightening rope 700 may be connected to the plurality of support bars 300 after passing through the plurality of elongated holes. Thus, the back appearance effect of the curtain sheet 200 can be ensured to be better.

In the present application, the number of the tension ropes 700 may be one or more, and the length direction of the tension ropes 700 is perpendicular to the length direction of the plurality of supports 300. For example, when the number of the tension strings 700 is one, the tension strings 700 may be disposed at the middle of the rear surface of the curtain sheet 200. The number of the tension ropes 700 may also be three, two side edges of the back surface of the curtain sheet 200 are respectively provided with one tension rope 700, and the middle position of the back surface of the curtain sheet 200 is provided with one tension rope 700.

In the embodiment of the present application, the screen sheet 200 in the projection screen 000 may be a sheet structure made of Polyethylene Terephthalate (PET), and the supporting bars 300 in the projection screen 000 may be a bar structure made of PET. It should be noted that, in practical applications, the thickness and width of the supporting strips 300 and the distance between every two adjacent supporting strips 300 can be set according to the size of the curtain sheet 200 and the winding diameter of the curtain sheet 200.

In practical applications, the part of the curtain sheet 200 wound around the winding drum 100 is likely to creep, and the part not wound around the winding drum 200 has a low probability of creeping. For this reason, the support strips 300 may not be provided or the distance between two adjacent support strips 300 may be made larger in the area where the back surface of the curtain sheet 200 not wound on the roll 100 is located. Thus, the number of support bars 300 used can be reduced, thereby reducing the overall weight of projection screen 000.

It should be noted that, in other possible implementations, the curtain sheet 200 and the supporting bar 300 in the projection screen 000 may also be made of other materials, and may be made of the same material or different materials, so as to ensure that the coefficient of thermal expansion of the curtain sheet 200 is similar to the coefficient of thermal expansion of the supporting bar 300, which is not specifically limited in this embodiment of the present application.

Optionally, please refer to fig. 14, fig. 14 is a schematic connection diagram of a support strip and a curtain sheet provided in the embodiment of the present application. At least some of the plurality of support bars 300 in projection screen 000 may be of solid construction and/or at least some of the plurality of support bars 300 may be of hollow construction. For example, a plurality of support bars 300 may each be provided as a hollow structure; alternatively, the plurality of support bars 300 may be provided as a solid structure; or a part of the plurality of supporting bars 300 may be a hollow structure, and another part may be a solid structure, which is not specifically limited in the embodiments of the present application. In the present application, as shown in fig. 14, when supporting bar 300 is a hollow structure, reinforcing ribs 301 may be provided in the hollow cavity of supporting bar 300, and supporting bar 300 is reinforced by reinforcing ribs 301. For example, the shape of the reinforcing rib 301 may be an elongated shape, or a "crescent shape", or another shape, which is not specifically limited in the embodiments of the present application.

In order to reduce the probability of the curtain sheet 200 being curled at the edge or being uneven, the curtain sheet 200 needs to be unfolded and folded many times during the use of the curtain sheet 200, and in the present application, the support strip 300 having a thermal expansion coefficient close to that of the curtain sheet 200 is disposed on the back of the curtain sheet 200 and is fixedly connected to the back of the curtain sheet 200.

When the curtain sheet 200 is curled, in order to prevent the curtain sheet 200 from being locally deformed, it is necessary to ensure that the curtain sheet 200 is well attached to the winding drum 100, that is, the support strips 300 are required to have a smaller thickness h, a smaller width w and a larger distance d between two adjacent support strips 300. For this purpose, it is necessary to ensure the maximum principal strain ε of the curtain sheet 200 _principal Less than the failure principal strain [ epsilon ] of the curtain 200]。

When the screen 200 is expanded, it is necessary to ensure that the picture projected onto the screen 200 by the projector has a good effect. That is, a greater thickness h of the supporting bars 300, a greater width w of the supporting bar 00 and a smaller interval d between the supporting bars 300 of adjacent two are required. For this purpose, it is necessary to ensure the maximum value max u of the out-of-plane displacement deformation (the maximum displacement of the curtain before and after deformation) of the curtain 200 under the combined action of the self-gravity and the wind pressure ₃ I.e. maximum max u of out-of-plane displacement deformation ₃ To be minimal.

The embodiment of the application aims to illustrate the influence of the width and the thickness of the supporting strips and the distance between two adjacent supporting strips on the maximum value of the out-of-plane displacement deformation of the curtain sheet. Referring to fig. 15, fig. 15 is a schematic view of the curtain when being unfolded. The support strip is schematically illustrated as a PET strip. The width w of the PET strip and the thickness of the PET striph and the distance d between two adjacent PET strips are design variables, and the maximum out-of-plane displacement max u of the curtain sheet 200 in the unfolded state ₃ Minimum is an objective function, and maximum principal strain epsilon of the curtain sheet in a curling state _principal Less than the principal strain of allowable failure [ epsilon ] of the curtain sheet 200]To optimize the constraints. The optimization problem formula can be:

find para＝[w，d，h]

min(max u ₃ )

s.t.ε _principai ＜[ε]

in summary, the embodiment of the present application provides a projection screen, which may include: the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips. The supporting strips fixedly connected with the back of the curtain sheet are arranged along the curling direction of the curtain sheet, and the ratio of the thermal expansion coefficient of the curtain sheet to the thermal expansion coefficient of the supporting strips is smaller than or equal to a target threshold value, namely the thermal expansion coefficient of the curtain sheet is close to that of the supporting strips. Thus, when the projection screen is in a high-temperature environment, the degree of thermal expansion of the screen sheet in the projection screen is close to that of the support strip. And after the curtain piece is connected with the support bar, the curtain piece is heated the inflation back, and is less to the pressure that a plurality of support bars were exerted, and it is less to make the support bar produce the degree of bucking deformation, and then makes a plurality of support bars can carry out effectual support to the curtain piece to reduced the curtain piece and after expanding many times and packing up, the probability of the bad phenomenon of edge curl or inside unevenness takes place for the curtain piece.

Referring to fig. 16, fig. 16 is a schematic structural diagram of a laser projection apparatus according to an embodiment of the present disclosure. The laser projection apparatus may include: a projection screen 000 and a projection host 001. Projection screen 000 may be any of the projection screens shown above.

In the embodiment of the present application, please refer to fig. 17, and fig. 17 is a schematic structural diagram of another laser projection apparatus provided in the embodiment of the present application. The projection device may further include: the housing unit 002 houses the projection host 001 and the projection screen 000 therein. The receiving portion 002 may have a transparent region 0021 and an opening 0022, the light beam emitted from the host projector 001 can penetrate through the transparent region 0021, and the lifting mechanism 600 can control the screen sheet 200 to pass through the opening 0022 and be unfolded. Thus, when the projection apparatus is not used, the projection host 001 and the projection screen 000 are accommodated in the accommodating portion 002, which facilitates space saving. When the projection apparatus is in use, the lifting mechanism 600 controls the screen 200 to be unfolded, and the projection host 001 projects a light beam onto the screen 200, so that the screen 200 displays a projection picture.

The vertical distance from the center point of the light-transmitting region 0021 to the plane of the developed screen 200 is equal to the product of the projection ratio of the projection host and the width of the display region on the screen, and the width of the display region refers to the size of the display region along the horizontal direction. Therefore, the light beam emitted by the projection host 001 can be accurately projected to the display area of the screen 200, so that the definition of the projection picture on the screen 200 is ensured.

Since the throw ratio is a performance parameter of the projection host 001 itself, the throw ratio of the projection host 001 is related to the selected projection host 001, that is, the throw ratio is different when different projection hosts 001 are selected, and thus the vertical distance from the center point of the transparent region 0021 to the plane where the expanded screen 200 is located is different. Thus, in the actual setting process, the vertical distance from the central point of the light transmitting area 0021 to the plane where the developed curtain sheet 200 is located is calculated through the projection ratio of the projection host 001 and the width of the display area, so that the light beam emitted by the projection host 001 can be completely projected on the display area of the curtain sheet 200.

Alternatively, the projection host 001 may be an ultra-short focus projection host, and the ultra-short focus projection host may be a DLP (Digital Light processing) projection host. In this way, the distance between the projection host 001 and the plane of the projection screen 000 is set to be short, so as to realize the miniaturization design of the whole projection device. The projection host 001 may include: a light source, an optical engine and a lens (not shown). The light source is used for emitting light beams to the optical machine.

The light engine may include: the Digital Micromirror Device (DMD) comprises a Digital Micromirror array (DMD) and a drive circuit board electrically connected with the DMD, wherein the drive circuit board in the optical machine is used for providing a drive signal for the DMD. The DMD can modulate the light beam emitted from the light source based on the driving signal, emit the modulated light beam to the lens, and emit the light beam to the screen in the projection screen 000 through the lens, so that the screen 200 can present a projection picture. For example, the projection host 001 includes a lens that is an ultra-short focus projection lens.

In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless explicitly defined otherwise.

The above description is intended to be exemplary only, and not to limit the present application, and any modifications, equivalents, improvements, etc. made within the spirit and scope of the present application are intended to be included therein.

Claims

1. A projection screen, comprising: the curtain comprises a winding drum, a curtain sheet and a plurality of supporting strips;

2. The projection screen of claim 1 wherein the curtain sheet and support bars are an integrally formed structure.

3. The projection screen of claim 1, further comprising: be located the curtain piece with connecting portion between the support bar, connecting portion respectively with the back of curtain piece with a plurality of support bar fixed connection, at the perpendicular to in the direction at the back of curtain piece, the thickness of connecting portion is less than the thickness of curtain piece, and is less than the thickness of support bar.

4. The projection screen of claim 3, wherein the connection portion comprises: the front projection of at least part of the support bars on the back surface of the curtain sheet is positioned in the front projection of the connecting sheet on the back surface of the curtain sheet;

and/or, the connecting part comprises: the curtain piece comprises a plurality of connecting strips, wherein the connecting strips are in one-to-one correspondence with at least partial supporting strips in the supporting strips, and the orthographic projection of each connecting strip on the back face of the curtain piece is positioned in the orthographic projection of the corresponding supporting strip on the back face of the curtain piece.

5. The projection screen of claim 4 wherein when the connection comprises: during a plurality of connecting strips, every the width of connecting strip is less than the width of corresponding support bar, and every the connecting strip be in orthographic projection on the back of curtain piece is located corresponding support bar is in orthographic projection's central area on the back of curtain piece.

6. A projection screen according to any one of claims 3 to 5 wherein the connection is an adhesive layer having adhesive properties or a magnetic sheet having magnetic properties.

7. The projection screen of claim 6 wherein when the connecting portions are the magnetic pieces, the support bars comprise: the support strip comprises a support strip body and metal particles distributed in the support strip body.

8. The projection screen of any one of claims 1-5 wherein the projection screen further comprises: the lifting mechanism is arranged on the base;

the reel with elevating system all fixes on the base, elevating system includes the crossbeam, the crossbeam with the second side fixed connection of curtain piece, the second side with first side does two relative sides in the curtain piece, elevating system is configured to: controlling the part of the curtain sheet wound on the winding drum to be unwound through the cross beam;

the tensioning ropes are fixedly connected with the support bars in sequence respectively, the tensioning ropes can be connected with the base and the cross beam respectively after the curtain sheet is unfolded by the lifting mechanism, and the tensioning ropes can be disconnected with at least one of the base and the cross beam before the curtain sheet is curled by the winding drum.

9. The projection screen of any one of claims 1 to 5 wherein the curtain sheet is a sheet structure made of polyethylene terephthalate (PET) and the support strips are strip structures made of PET.

10. The projection screen of claim 9 wherein at least some of the plurality of support bars are solid structures and/or at least some of the plurality of support bars are hollow structures.