screen

Abstract

To provide a technique of a display device in which a screen can be moved by slight force, as the display device for which a user can easily view in a dorsal position or a side lying position, the screen used for the display device should be light weight, however, conventional screens are configured so that, between four beams forming a screen frame and a screen membrane, a tension coil spring is attached for applying tensile force to the screen membrane, therefore for solving a practical use problem in distortion of the beam to the tensile force, the beams require constant mass, therefore light weight cannot be easily achieved.SOLUTION: On a rear surface of a screen membrane which has multiple spring engagement holes on a peripheral part of the screen membrane, a screen frame formed of crossed multiple beams are adhered, the screen membrane peripheral part is bent along the screen frame, and between the spring engagement holes and multiple spring engagement parts attached to the beams, tension coil springs are respectively provided in a screen. The material of the screen frame has a specific gravity of 0.075 or lower and a Young's modulus of 250 MPa or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technical field relating to a display device screen that is easy to view when lying on one's back or side. [Background technology]

[0002] As a display device that is easy to view when lying on one's back or side, a technology has been disclosed that allows the position of the screen to be moved with a slight force (see Patent Document 1). [Patent Document 1] In this device, the screen and projector are integrated by an arm or the like, and by appropriately selecting the positions of the screen, arm, projector, balancer, etc. and providing a rotation axis at approximately the center of gravity of the device, the device can be rotated with a light force and the screen can be easily brought into a position that is easy to view when lying on one's back or side.

[0003] As for the projector screen, a technology has been disclosed in which a screen frame surrounds the screen film from the outside and multiple tension coil springs are provided between the screen frame and the screen film to keep the screen film flat (see Patent Document 2). [Patent Document 2] JP Patent Publication No. 04-040439 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional techniques have the following problems. That is, in a display device with a structure such as that of Patent Document 1, the screen needs to be as lightweight as possible, but in the technology of Patent Document 2, tension coil springs are attached between the four beams that make up the screen frame and the screen film to apply tension to the screen film, and the beams need to have a geometric moment of inertia that is large enough to withstand this tension and ensure that the distortion of the beams does not cause practical problems, and there was a problem that the mass of the screen frame would increase in order to obtain the required geometric moment of inertia.

[0005] Furthermore, for a display device with a structure like that of Patent Document 1, the goal was to have a screen that was 751 mm wide and 424 mm long, with a mass of 80 grams or less. Several prototypes were made, but there was an issue that it was not clear whether this goal would be achieved because the screen frame was made of metal.

[0006] The present invention has been made in consideration of the problems with the conventional technology described above, and aims to realize a lightweight screen for use in a display device that can be moved with a light force whether lying on one's back or on either side. [Means for solving the problem]

[0007] In order to solve the problems of the prior art and achieve the above-mentioned object, the screen of the present invention described in claim 1 is characterized in that a screen frame made up of a plurality of intersecting beams is attached to the back surface of a screen membrane having a plurality of spring locking holes on the periphery of the screen membrane, the peripheral portion of the screen membrane is folded along the screen frame, and a tension coil spring is provided between each of the spring locking holes and a plurality of spring locking portions attached to the beams.

[0008] In order to solve the problems of the prior art and achieve the above-mentioned object, claim 2 of the present invention provides that the screen frame described in claim 1 is made of a material having a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more. Effect of the Invention

[0009] According to the invention described in the first claim, a screen frame composed of a plurality of intersecting beams is attached to the back surface of a screen membrane having a plurality of spring engagement holes around the periphery of the screen membrane, the peripheral portion of the screen membrane is bent along the screen frame, and a tension coil spring is provided between each of the spring engagement holes and the plurality of spring engagement parts attached to the beams. While tension is applied perpendicular to the beams in Patent Document 2, in this embodiment, tension is applied in the same direction as the beams, thereby reducing the burden on the beams and enabling the mass of the beams and the screen frame composed of the beams to be reduced.

[0010] According to the invention described in the second claim, the screen frame is made of a material having a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more, which is effective in reducing the mass of the screen frame. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram of a screen in the first and second embodiments; [Diagram 2] A development view of the screen film in the first embodiment. [Diagram 3] FIG. 1 is an explanatory diagram of a screen frame in the first and second embodiments; [Figure 4] Cross section AA of Figure 1 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First embodiment This embodiment is a first embodiment corresponding to the invention defined in claim 1, and Figs. 1, 2, 3 and 4 are diagrams for explaining the screen in this embodiment.

[0013] FIG. 1 is an explanatory diagram of a screen in a first embodiment, and is a diagram showing the back side of the screen of the present invention, that is, a view opposite to the surface onto which an image is projected.

[0014] FIG. 2 is a development view of the screen membrane before assembly in the first embodiment, showing the back surface 202 of the screen membrane and a plurality of spring locking holes 203 in the peripheral portion 205 of the screen membrane.

[0015] FIG. 3 is a rear view of the screen frame 102 in the first embodiment. This screen frame is composed of beams 101 that cross vertically and horizontally, and has multiple spring engagement portions 302 attached near the ends of the beams. Here, the screen frame holding part 103 is made of the same material as the other parts of the screen frame, but its thickness has been reduced to reduce the mass of the screen, and hook-and-loop fastener (registered trademark) is attached to this part and also to the arm side, making it easy to attach and detach the screen to the arm.

[0016] FIG. 1 shows the screen frame 102 of FIG. 3 placed on the back surface 202 of the screen membrane of FIG. 2, the peripheral portion 205 of the screen membrane folded twice along the screen frame, and a tension coil spring 301 attached between the spring engagement portion 302 on the back side of the screen frame and the spring engagement hole 203 on the peripheral portion of the screen membrane. The front surface 201 of the screen membrane that is exposed as a result of the screen membrane being folded is also shown.

[0017] FIG. 4 is a cross-sectional view of AA in FIG. 1, showing how the screen membrane is folded twice along the beam 101, and how a tension coil spring 301 is attached between the spring locking hole 203 of the screen membrane and the spring locking portion 302 that appears on the back side of the screen frame, thereby applying tension to the screen membrane. The spring locking hole is reinforced with a spring locking hole reinforcing part 204, which serves to distribute the tension of the spring to the screen membrane.

[0018] Advantages of the First Embodiment Whereas in Patent Document 2, tension is applied perpendicular to the beams, in the present embodiment, tension is applied in the same direction as the beams, thereby reducing the burden on the beams and having the effect of reducing the mass of the beams and the screen frame composed of the beams.

[0019] In order to clarify the effect of the mass reduction, the strain when a force is applied perpendicular to the beam and when a force is applied in the direction of the beam are compared.

[0020] When a beam of length L with a square cross section of a material with Young's modulus E and side length b1 is supported at both ends and a force W is applied perpendicular to the beam direction to the center of the beam, the strain of the beam δ1 is expressed by the following equation.

number

[0021] When a material with Young's modulus E is used and a force W is applied in the direction of a beam with length L and a square cross section with one side of length b2, the strain of the beam δ2 is expressed by the following equation.

number

[0022] If the strain amounts δ1 and δ2 are equal, that is, the strain caused by the force applied from the lateral direction is equal to the strain caused by the force applied from the beam direction, the relationship between the lengths b1 and b2 of the square cross section sides is expressed by the following formula.

number

[0023] Second embodiment This embodiment corresponds to the second embodiment of the invention as defined in claim 2, and Figs. 1, 3, and 4 are diagrams for explaining a screen frame 102 in this embodiment. The third embodiment is characterized in that the screen frame is made of a material having a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more.

[0024] An example of the material for the screen frame is the product name "Decopane A1 Base Board (B)" sold by Koyo Sangyo Co., Ltd. This product is commonly known as "styrene paper," and actual measurements showed that it had a specific gravity of 0.07 and a Young's modulus of 278 MPa.

[0025] A prototype of screen frame 102 with dimension C in Figure 4 of 20 mm, dimension B in Figure 3 of 5 mm, width of 751 mm, height of 424 mm, and thickness of screen frame holding part 102 of 5 mm was made by cutting the above-mentioned styrene paper to create 10 beams and 4 corners, which were bonded together with a polystyrene foam adhesive, and then 16 spring locking parts made from processed aluminum plate were bonded to the beams in the desired positions using a multi-purpose adhesive.

[0026] The screen membrane was cut out of construction paper 788 mm wide, 545 mm long, and weighing 23 grams, as shown in Figure 2, and 2 mm washers were used for the spring locking hole reinforcement parts 204. Sixteen of these were attached using multi-purpose adhesive in the positions shown in Figure 2, and then spring locking holes 203 were drilled in the construction paper to create a prototype.

[0027] A prototype screen frame was placed on the prototype screen membrane, and the peripheral part of the screen membrane was folded twice along the screen frame. Sixteen tension coil springs (product name: E501) made by Accurate Corporation were attached between the spring locking holes and spring locking parts to produce a prototype screen as shown in Figure 1. As a result, sufficient tension was obtained in the screen membrane, the flatness presented no practical problems, and the total mass of the screen was 70 grams.

[0028] A prototype was made using the above-mentioned styrene paper, but for mass production it is desirable to use raw materials and a molding method that will result in a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more after molding, as specified in the claims.

[0029] Advantages of the Second Embodiment In this embodiment, a lightweight, highly rigid material with a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more is used for the screen frame, which has the effect of making the screen frame significantly lighter than that of Patent Document 2, which uses a metal frame. [Explanation of symbols]

[0030] 101...beam 102···Screen frame 103 Screen frame holding part 201 Screen membrane front surface 202 Back side of screen membrane 203 Spring locking hole 204 Spring locking hole reinforcement part 205 Screen periphery 301...Tension coil spring 302 Spring locking portion

Claims

1. A screen frame made up of a plurality of intersecting beams is attached to the rear surface of the screen membrane having a plurality of spring locking holes on the periphery of the screen membrane, the peripheral portion of the screen membrane is bent along the screen frame, and a tension coil spring is provided between each of the spring locking holes and the plurality of spring locking parts attached to the beams.

2. 2. The screen frame according to claim 1, which is made of a material having a specific gravity of 0.075 or less and a Young's modulus of 250 MPa or more.

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