WO2019218701A1

WO2019218701A1 - Projection screen and projection system comprising projection screen

Info

Publication number: WO2019218701A1
Application number: PCT/CN2019/070525
Authority: WO
Inventors: 黄旻; 李屹
Original assignee: 深圳光峰科技股份有限公司
Priority date: 2018-05-18
Filing date: 2019-01-05
Publication date: 2019-11-21
Also published as: CN110501869A

Abstract

Provided are a projection screen (1) and a projection system comprising the projection screen (1). The projection screen (1) comprises: a screen surface (10), wherein a hanging nail (14) is provided on a rear surface of the screen surface (10) at each side of each of four corners of the screen surface (10); a basic frame (20), the basic frame (20) having a frame shape corresponding to an outer contour of the screen surface (10), and a protrusion (24) being formed in a protruding manner on a front surface, facing the rear surface of the screen surface (10), of the basic frame (20) at the top point of each of the corners of the basic frame (20); and tensioning elements (13), a tensioning element (13) being hung at each of the corners of the screen surface (10) and between each hanging nail (14) and each protrusion (24) so as to tension the screen surface (10) on the basic frame (20). This invention can effectively reduce the requirements for the precision of a manufacturing process and components and the requirements for an assembly process, and can also meet product requirements.

Description

Projection screen and projection system including projection screen

Technical field

The present invention relates to a fixed structure for a screen of a projection screen. More specifically, the present invention relates to projection screens and projection systems including projection screens.

Background technique

Currently, projection screens have become commonplace. During the manufacturing process, an adhesive is used to attach the screen to the substrate, or a plurality of tensioning elements are used to tension the screen surface to the basic frame. This manufacturing process is complicated and has many problems.

Specifically, the Fresnel optical screen is usually bonded to a substrate (usually a honeycomb aluminum plate) with an adhesive, and then the outer frame is covered on the outside. The black grid optical screen is typically secured to the base frame using a plurality of tensioning elements at the periphery.

However, for the Fresnel optical screen, if the substrate processing accuracy is not high, especially if the substrate flatness deviation is too large, it is easy to cause the screen surface to be uneven, or the partial bulging caused by the temperature change in the case of partial air trapping. The phenomenon that produces the product is not good. For the black-gate optical screen, during the assembly process, due to the excessive number of tensioning elements, the screen is prone to skew and multiple assembly is required.

In addition, in the manufacturing process of the basic frame, the frame is usually directly formed into a connecting shape, and the frame end is processed according to a sharp angle of 45° to meet the requirement of a 90° corner after the frame is spliced. The precision of the processing of such a frame is high, and the assembly corner requires special calibration.

Summary of the invention

In view of the above problems, it is an object of the present invention to provide a projection screen capable of effectively reducing the precision requirements and assembly process requirements of the fabricated process and components while at the same time meeting the requirements of the product and a projection system including the projection screen.

According to a first aspect of the present invention, there is provided a projection screen comprising: a screen surface on a rear surface of the screen surface, each of the four corners of the screen surface Each side edge is provided with a peg; a basic frame having a frame shape corresponding to an outer contour of the curtain surface, and a front surface of the rear surface of the basic frame facing the curtain surface Above, a protrusion is protrudedly formed at an apex of each corner of the basic frame; and a tensioning element, at each corner of the curtain, each of the pegs and the protrusions The tensioning elements are interposed therebetween to thereby tension the screen to the basic frame.

In addition, the projection screen may further include: an outer base and an inner base, wherein the outer base and the inner base are respectively fixed at the front of the screen at each corner of the screen Side and back side. Each of the pegs may be disposed in the outer base, the screen surface, and the inner base.

In addition, the basic frame may include: an inner bezel disposed on each side of the basic frame; a corner portion disposed between ends of each two adjacent the bezel; and a connecting plate, The connecting plate is used to connect the inner frame and the corner portion at each corner of the basic frame.

In addition, the protrusion may be formed on the corner portion.

In addition, the inner bezel may be manufactured by using a straight cut process.

In addition, one of the connecting plate and the corner portion may be provided with a positioning protrusion, and the other may be provided with a positioning hole for inserting the positioning protrusion.

In addition, a screw hole may be formed in the positioning protrusion to connect the connecting plate and the corner portion by screws.

In addition, the positioning protrusion may be connected to the connecting plate and the corner portion by riveting.

Additionally, the basic frame may also include a locating pin. The positioning pin may position the inner frame on the connecting plate by a positioning hole inserted at a corresponding position of the connecting plate and the inner frame.

Additionally, the face may be rectangular.

Additionally, the outer base may be "L" shaped, and the corner portion of the outer base may coincide with the corner of the face.

Additionally, the inner base may be triangular, and a right angle portion of the inner base may coincide with a corner of the screen.

In addition, the projection screen may further include a fastener, the fastener may be respectively screwed into the screw holes of the inner base, the curtain surface and the outer base to respectively respectively the outer base The seat and the inner base are fixed to the front side and the rear side of the screen.

In addition, the pegs may respectively fix the outer base and the inner base to the screen by screwing into the screw holes of the inner base, the curtain surface and the outer base The front side and the back side of the face.

In addition, the projection screen may further include an outer frame on each side, and the outer frame may be fixed on the basic frame to cover a peripheral edge of the basic frame.

In addition, the peg may be formed with a limiting portion spaced apart from the peg head by a first predetermined distance to form a clamping element between the limiting portion and the peg head for abutting Clearance.

According to another aspect of the present invention, a projection system including a projection screen according to each of the above examples is provided.

According to the present invention, since the tensioning elements are respectively tensioned in the two corner directions of the screen surface in the Y-axis direction and the Z-axis direction, the curtain surface can be firmly fixed to the frame. . Therefore, the processing or assembly requirements can be reduced, resulting in an increase in the yield of the product.

Further, according to the present invention, since the tensioning member is disposed only in the region of the inner base located inside the corner portion of the face, and thus the basic frame has a frame shape corresponding to the face, the basic of the projection screen can be effectively reduced. Frame size. Accordingly, the outer frame can be made small, and the size of the outer frame can be reduced.

Further, according to the present invention, since the corner portion is provided, the end portion of the inner frame can be manufactured by straight cutting. Therefore, compared with the prior art, the processing precision requirements of the frame are reduced, and no additional corner alignment is required for assembly, thereby reducing manufacturing expenditure and ensuring the quality reliability of the basic frame of the screen. In addition, the connecting plate is provided with a positioning pin, which can reduce the processing or assembly requirements of the basic frame, so that the yield of the product rises.

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below, and the drawings in the following description are only some embodiments of the present invention. Other embodiments and their drawings may be derived from the embodiments shown in the drawings without departing from the scope of the invention.

Figure 1 shows a front view of a projection screen in accordance with the present invention.

Figure 2 shows a rear view of a projection screen in accordance with the present invention.

3 and 4 respectively show a rear oblique upper view and a front oblique upper view of the screen assembly at the upper right corner of the projection screen according to the present invention.

FIG. 5 shows a disassembly diagram corresponding to FIG.

Fig. 6 shows a front side view of the overall structure of the basic frame.

Fig. 7 is a disassembled view showing the upper left corner of the basic frame of Fig. 6.

Figure 8 shows an assembled view of the upper left corner of the basic frame of Figure 6.

Figure 9 shows a view for securing a screen assembly to a base frame by means of a tensioning element.

Figure 10 shows the ends of the bezel and the outer bezel of the basic frame in accordance with the present invention.

Detailed ways

The technical solutions of the various embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Note that the drawings are schematic and are not drawn based on actual scales. The relative dimensions and proportions of the components illustrated in the figures are exaggerated or reduced in size, and any dimensions are merely exemplary and not limiting. The same structures, elements or components in the drawings are denoted by the same reference numerals. In addition, all the connection/fixation relationships mentioned herein are not directly connected to the components, but rather may constitute a better connection/fixation structure by adding or reducing auxiliary parts according to specific implementations.

Projection screen overall structure

1 and 2 illustrate a projection screen 1 in accordance with an embodiment of the present invention. Specifically, FIG. 1 shows a front view of the screen 1, and FIG. 2 shows a rear view of the projection screen 1. Here, the front side direction of the screen 1 (ie, the direction facing the viewer) is defined as the X-axis direction, the right side direction of the screen 1 is defined as the Y-axis direction, and the upper side direction of the screen 1 is defined as the Z-axis direction. direction.

As shown in FIGS. 1 and 2, the screen 1 includes a screen 10, a base frame 20, and an outer frame 30. As will be described in detail below, in the screen 1, the screen 10 is fixed to the base frame 20, and the outer frame 30 is attached to the base frame 20.

Note that in the front view of Figure 1, the base frame 20 is occluded and invisible to the viewer.

Screen component

3 and 4 illustrate screen components of one corner of the screen 1 (i.e., the upper right corner of the screen 1 in Fig. 1) in accordance with an embodiment of the present invention. 3 is a partial view obtained by observing the screen obliquely from the rear side, and FIG. 4 is a view obtained by observing the screen obliquely from the front side. In addition, FIG. 5 shows a disassembly diagram corresponding to FIG.

The screen assembly of the projection screen 1 includes a screen 10, an inner base 11, an outer base 12, tensioning elements 13 (not shown in Figures 3-5), pegs 14 and fasteners 15, and the like.

In this example, the face 10 is generally rectangular in shape.

On the front side of the face 10 (i.e., the side facing the viewer), the outer base 12 is disposed at each corner of the face 10. The outer base 12 can have a variety of shapes. In the present example, in order to prevent the observer from observing the screen 10 as much as possible, the outer base 12 may have an "L" shape, and the corner portions coincide with the corners of the screen surface 10.

On the rear side of the face 10, the inner base 11 is disposed at each corner of the face 10. The inner base 11 can also be of various shapes. In the present example, the inner base 11 is a right-angled triangle, and the right-angled portion coincides with the corner of the screen surface 10.

Moreover, as shown in FIGS. 3 and 4, as an example, the amount of extension of the outer base 12 on each side of the corner of the face 10 (i.e., the amount of extension in the Y-axis direction and the Z-axis direction) may be It is approximately equal to the corresponding extension of the inner base 11.

The inner base 11 and the outer base 12 are fastened to the rear side and the front side of the screen 10 by fasteners 15, respectively, such that the respective corners of the screen 10 are sandwiched between the inner base 11 and the outer base 12. . Specifically, for example, the screen surface 10 may form a screw hole on each side of the corner portion, and a screw hole may be formed at a corresponding position of the inner base 11 and the outer base 12. Therefore, the face 10, the inner base 11 and the outer base 12 are fastened together by screwing the respective fasteners 15, for example, into the screw holes of the face 10, the inner base 11, and the outer base 12. For example, the form of fastening includes, but is not limited to, a form of a detachable connection or a non-detachable connection such as a screw, a bolt, a rivet, or the like.

The pegs 14 can be secured to the inner base 11 from the rear side of the face 10. In the present example, in order to achieve a better fixing structure, the pegs 14 are sequentially inserted into the screw holes of the inner base 11, the curtain surface 10 and the outer base 12 from the rear side of the screen surface 10, and are screwed into the screw. In the hole. As shown in FIGS. 3 to 5, a peg 14 is provided on each side of the corner of the face 10, and the position of the pegs 14 is spaced apart from the corners of the corners of the face 10.

As shown in FIG. 5, the pegs 14 are provided with a limiting portion 16 spaced apart from the peg head 17 by a first predetermined distance, thereby forming a hooking tension between the limiting portion 16 and the peg head portion 17. The gap of the element 13 to define the abutment position of the corresponding tensioning element 13. Alternatively, instead of providing the limiting portion 16, a recess for abutting the tensioning element 13 may be provided at a position of the screw of the peg 14 corresponding to the gap. In this case as well, the same effect as the stopper can be achieved.

Therefore, according to the present invention, one end of the tensioning member 13 can be accurately attached to the peg 14 by providing the pegs 14 of the limited portion. During the assembly of the projection screen, it is not necessary to additionally adjust the abutment position of the tensioning element, thereby facilitating mass production.

Of course, the anchoring of the tensioning element can also be achieved in other known ways.

Here, the tensioning element 13 can be an elastic element such as a spring.

As an example, the pegs 14 may also have the function of being able to fasten the face 10, the inner base 11 and the outer base 12 together. In this case, some or all of the fasteners 15 may be omitted.

Note that the screen components of the screen 1 at the four corners are the same, and thus the detailed description of the screen components at one particular corner above also applies to the screen components at the other three corners.

Basic framework

The basic frame 20 according to an embodiment of the present invention will be described in detail below with reference to FIGS. 6, 7, and 8. FIG. 6 shows a front side view of the overall structure of the basic frame 20. FIG. 7 shows a disassembled view of the upper left corner of the basic frame 20 of FIG. 6. FIG. 8 shows an assembled view of the upper left corner of the basic frame 20 of FIG. 6.

As shown in FIGS. 6 to 8, the basic frame 20 has a frame shape corresponding to the outer contour of the screen surface 10, and includes an inner bezel 21, a corner portion 22, and a connecting plate 23. Note that FIG. 6 shows the corner portion 22 only at the upper right corner of the basic frame 20, and in fact, each corner portion of the basic frame 20 is provided with the corner portion 22.

An inner bezel 21 is disposed on each side of the basic frame 20, and at each corner of the basic frame 20, a corner portion 22 is disposed between the ends of two adjacent inner bezels 21. The connecting plate 23 connects and fixes the inner bezel 21 and the corner portion 22 together by screwing, riveting or the like to form a frame shape. In this example, as shown, the above fixing is achieved by screws.

Note that the length of the inner bezel 21 on the vertical side of the basic frame 20 and the inner bezel 21 on the horizontal side may not be the same. For example, in the case where the face 10 is rectangular, the length of the inner frame 21 on the vertical side may be different from the length of the inner frame 21 on the horizontal side. Nevertheless, in the present application, since the inner bezel 21 on the vertical side and the inner bezel 21 on the horizontal side differ only in length, both are collectively referred to as an inner bezel.

The connecting plate 23 may have an "L" shape with a symmetrical design. In the present example, the connecting plate 23 is coupled to each of the inner bezel 21 and the corner portion 22. In order to make the connecting plate 23 invisible in the assembled state, the connecting plate 23 may connect the respective inner bezel 21 and the corner portion 22 on the front side of the basic frame 20.

As shown in FIG. 7, for example, in order to connect the connecting plate 23 to each of the corner portions 22, positioning projections 25 for positioning the connecting plates 23 are formed on the front surface of the corner portion 22, and at corresponding positions of the connecting plates 23. A positioning hole 27 is formed. Thereby, by fitting the positioning projection 25 into the positioning hole 27 in a cooperative manner, the connecting plate 23 can be accurately connected and positioned on the corner portion 22.

Further, as shown in FIG. 7, a screw hole may be formed in the positioning projection 25. For example, the screw 26 or the like is screwed into the screw hole in the positioning hole 27 and the positioning projection 25, thereby further improving the connection between the connecting plate and the corner portion.

As an alternative example, the positioning projections 25 can also be connected and positioned on the corner portion 22 by riveting. In this case, the screw holes, the screws 26, and the like can be omitted. At this time, in addition to the positioning function, the positioning projection 25 also acts on the riveted stud.

Of course, as an alternative, a positioning hole may be formed in the corner portion 22, and a positioning protrusion may be formed on the connecting plate 23.

Meanwhile, as shown in FIG. 7, for example, in order to connect the respective inner frames 21 through the connecting plate 23, positioning holes are formed at respective positions of each of the connecting plate 23 and the inner bezel 21, by inserting the positioning pins 28 into these positions. In the hole, the relative position between the inner bezel 21 and the connecting plate 23 can be accurately positioned. In this way, even if the end of the inner bezel 21 is manufactured by straight cutting, that is, without the inner bezel 21 being machined to have a 45° sharp angle, no additional corner alignment is required for assembly. , thereby reducing manufacturing expenses. Subsequently, the web 23 and the inner bezel 21 are fastened together by screws or other suitable means of attachment.

In addition, as shown in FIGS. 7 and 8, projections 24 are formed projectingly at the corner vertices on the front side surface of the corner portion 22 (corresponding to the corner apex of the screen surface 10) to allow the tensioning member 13 to be The other end opposite to the end to which the hanging nail 14 is attached is abutted on the corner portion 22.

According to the present invention, since the corner portion 22 is provided, the end portion of the inner bezel 21 can be manufactured by straight cutting processing without processing the inner bezel 21 to have a 45° sharp angle. That is, according to the present invention, the 90° rotation angle requirement of the frame stitching is achieved by providing the corner portion 22. Therefore, compared with the prior art, the processing precision requirements of the frame are reduced, and no additional corner alignment is required for assembly, thereby reducing manufacturing expenditure and ensuring the quality reliability of the basic frame of the screen. In addition, the connecting plate 23 is provided with a positioning pin 28 so that the inner bezel 21 can be accurately positioned. Further, the processing or assembly requirements of the basic frame can be reduced, resulting in an increase in the yield of the product.

In addition, since the basic frame is realized by connecting the inner frame and the corner portion through the connecting plate, the structure of the basic frame is simpler and easier to manufacture than the prior art, thereby improving the yield.

In the assembled state of the screen 1, the projection 24 is spaced apart from the peg 14 by a second predetermined distance so that when the tensioning element 13 is hooked on the peg 14 at one end and is hung on the projection 24 at the other end, tensioning Element 13 is in tension. That is, the second predetermined distance between the projection 24 and the peg 14 is greater than the free length of the tensioning element 13, i.e., the length of the tensioning element 13 in the unloaded state.

As another example, the inner bezel 21 and the corner portion 22 may also be integrally formed as the basic frame 20. At this time, the connecting plate 23 can be omitted.

FIG. 9 shows a view in the case where the screen assembly is fixed to the basic frame 20 by the tensioning member 13.

As shown in Figure 9, a tensioning element 13 is provided along each side of each corner of the screen 10. That is to say, two tensioning elements 13 are arranged for each corner of the screen 10, one of which is arranged in the Y-axis direction (left-right direction, horizontal direction) and the other tensioning element 13 is arranged In the Z-axis direction (up and down direction, vertical direction). The two tensioning elements 13 are commonly connected to the projections 24 at one end, and the other ends of the respective tensioning elements 23 are respectively connected to the respective pegs 14.

At this time, the tensioning member 23 is in a tension state, whereby the screen surface 10 is tensioned on the basic frame 20 in both the Y-axis direction and the Z-axis direction.

In addition, the screen 1 can also have an outer bezel 30 on each side. The outer frame 30 may be fixed to the base frame 20 and cover the peripheral edge of the base frame 20. In the present application, similarly, the inner frame is collectively referred to as an outer frame because the outer frame 30 on the vertical side and the outer frame 30 on the horizontal side differ only in length.

FIG. 10 shows one end of the inner bezel 21. Note that both ends of the inner bezel 21 are the same. The inner bezel 21 is an elongated plate material, and a portion of the inner bezel 21 on the outer peripheral edge of the basic frame 20 has a cross-sectional shape.

FIG. 10 also shows one end of the outer bezel 30. Note that both ends of the outer frame 30 are the same. For example, in order to realize the connection of the inner bezel 21 and the outer bezel 30, the cross section of the outer bezel 30 is formed in a substantially C-shape to be fitted with the lip-shaped portion of the inner bezel 21.

Assembly process

The assembly process of the screen 1 will be explained below.

First, assemble the screen components. The inner base 11 and the outer base 12 are respectively disposed on the rear side and the front side of the screen 10 by fasteners 15, and then the pegs 14 are connected from the rear side to the inner base 11, the curtain 10, and the outer base. Block 12 in. Here, a peg 14 is respectively disposed on the edges of both side edges of the corner vertices of the screen assembly. As described above, the inner base 11 and the outer base 12 can also be disposed on the rear side and the front side of the screen surface 10 directly by the pegs 14, respectively. Thereby, the assembly of the screen components is completed.

Next, the basic frame 20 is assembled. First, the positioning projection 25 is inserted into the positioning hole 27, thereby positioning the connecting plate 23 on the corner portion 22. Then, the respective connecting plates 23 and the corner portions 22 are joined by screwing a fastening screw or the like into the screw holes of the positioning projections 25 and the positioning holes 27. Next, the end portion of the inner bezel 21 is positioned on the connecting plate 23 by inserting the positioning pin 28, and then the connecting plate 23 and the inner bezel 21 are fastened by, for example, a screw. Thereby, the assembly of the basic frame 20 is completed.

Next, at each corner of the screen assembly, the screen assembly is tensioned in the Y-axis direction and the Z-axis direction by the respective tensioning members 13. Specifically, one end of each tensioning member 13 is abutted against the projection 24 of the corner portion 22, and the other end is abutted against the corresponding peg 14 so as to be in a tensioned state.

Finally, the outer frame 30 is assembled on the base frame 20 and covers the peripheral edge of the base frame 20, thereby obtaining the screen 1 as shown in FIGS. 1 and 2.

Note that the steps of assembling the screen component and the steps of assembling the basic frame are in no particular order and can also be performed simultaneously.

According to the present invention, since the tensioning elements are respectively tensioned in the two directions of the Y-axis direction and the Z-axis direction at the four corner positions of the screen surface, the curtain surface can be firmly fixed to the frame. . Accordingly, the processing or assembly requirements can be reduced, resulting in an increase in the yield of the product.

Modification

In the above embodiment, the shape of the face 10 is implemented as a rectangular shape, but the present invention is not limited to a specific shape, and may be any shape. For example, in the case where the face 10 is non-rectangular, the inner base 11 and the outer base 12 can be fixed at four predetermined corners of the face 10. For example, the four predetermined corners may be the inscribed rectangle of the face, especially the four corners of the inscribed rectangle of the largest area. At this time, the inner base 11 and the outer base 12 may be formed in such a shape that their outer edges coincide with the outer edges of the screen surface 10. Moreover, the basic frame 20 and the outer frame 30 are formed to have a frame shape corresponding to the outer contour of the screen surface 10.

In general, the probability of unevenness of the screen surface and/or local bulging occurring in the central portion of the screen surface is high. According to the present invention, even if the face 10 is of a non-rectangular shape, by stretching and fixing the face 10 on the base frame 20 at the four corners of the inscribed rectangle, it is possible to eliminate the occurrence of the inscribed rectangle. Uneven and/or partial bulging.

Further, in the above embodiment, the inner base 11 and the outer base 12 are provided at respective corners of the screen surface 10. The inner base 11 and the outer base 12 can improve the stability of the screen fixing structure and can protect the corners of the screen surface 10 from damage. However, in the case where the application environment is friendly or the screen 10 is formed of a material that is not easily damaged, the inner base and the outer base may not be provided. In this case, the pegs 14 are directly fixed to each side of each corner of the face 10.

Further, in the above embodiment, the tensioning member 13 is implemented as a tension spring, but may be implemented as another member capable of providing a pretensioning force, such as a tension band or the like.

Application example

The present invention also proposes a projection system using the projection screen proposed in the above embodiment. Such a projection system can include a projection screen 1 as well as a projector. The projector emits projection light and projects it onto the front side of the projection screen 1 (the side facing the viewer), whereby the viewer can view the content displayed on the projection screen 1, such as a video, an image, and the like.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto, and those skilled in the art will understand that the present invention may be practiced without departing from the spirit or scope of the appended claims. Make various changes, combinations, sub-combinations, and variants.

Claims

A projection screen comprising:

a curtain surface, on each of the four corners of the screen surface, a hanging nail is disposed on a rear surface of the screen surface;

a basic frame having a frame shape corresponding to an outer contour of the screen surface, and on a front surface of the rear surface of the base frame facing the screen surface, each corner of the basic frame a protrusion is prominently formed at an apex of the portion;

a tensioning element at each corner of the face, each of the pegs and the projection being hooked with the tensioning element to thereby tension the facet in the On the basic framework.
The projection screen of claim 1, wherein the projection screen further comprises:

An outer base and an inner base, the outer base and the inner base being respectively fixed at a front side and a rear side of the screen surface at each corner of the screen surface,

Wherein each of the pegs is disposed in the outer base, the curtain surface and the inner base.
The projection screen of claim 1 wherein said basic frame comprises:

An inner frame disposed on each side of the basic frame;

a corner portion disposed between ends of each two adjacent of the bezels;

a connecting plate for connecting the inner frame and the corner portion at each corner of the basic frame.
The projection screen of claim 3, wherein the protrusion is formed on the corner portion.
The projection screen of claim 3, wherein the inner bezel is manufactured by using a straight cut process.
The projection screen according to claim 3, wherein one of the connecting plate and the corner portion is provided with a positioning projection, and the other is provided with a positioning hole for inserting the positioning projection.
The projection screen according to claim 6, wherein a screw hole is formed in the positioning projection to connect the connecting plate and the corner portion by screws.
The projection screen according to claim 6, wherein the positioning projection connects the connecting plate and the corner portion by riveting.
The projection screen of claim 3, wherein the basic frame further comprises a positioning pin,

Wherein the positioning pin positions the inner frame on the connecting plate by a positioning hole inserted at a corresponding position of the connecting plate and the inner frame.
The projection screen of claim 2, wherein the screen is rectangular.
The projection screen of claim 10, wherein the outer base is "L" shaped, and a corner portion of the outer base coincides with a corner of the face.
The projection screen of claim 10, wherein the inner base is triangular, and a right angle portion of the inner base coincides with a corner of the face.
The projection screen of claim 2, wherein the projection screen further comprises a fastener, the fastener being screwed into the screw hole of the inner base, the screen surface, and the outer base The outer base and the inner base are respectively fixed to the front side and the rear side of the screen surface.
The projection screen of claim 2, wherein the pegs respectively connect the outer base and the screw in the screw holes of the inner base, the screen surface and the outer base The inner base is fixed to the front side and the rear side of the screen surface.
The projection screen of claim 1, wherein the projection screen further includes an outer frame on each side, the outer frame being fixed to the base frame to cover a peripheral edge of the base frame.
The projection screen according to claim 1, wherein the peg is formed with a stopper spaced apart from the peg head by a first predetermined distance to be between the stopper and the peg head A gap for abutting the tensioning element is formed.
A projection system comprising the projection screen of any one of claims 1 to 16.