JP2006171563A - Projection screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively attain a projection screen easily stored and having excellent operability by simple constitution. <P>SOLUTION: The projection screen is provided with: a magnet sheet; a reflection layer formed on the surface of optical image projecting side of the magnet sheet and capable of reflecting the optical image; a shaft fixed to one side of the magnet sheet; and a winding/fixing part formed, in the other side opposing to the one side of the magnet sheet to which the shaft is fixed, on the same face as the reflection layer, and when winding the magnet sheet around the shaft so that the reflection layer becomes inside thereof, the winding/fixing part is allowed to be attracted to the outside of the magnet sheet already wound around the shaft by magnetic force to fix the magnet sheet in a state of being wound around the shaft. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projection screen. In particular, the present invention relates to a flexible projection screen that is attached to a wall surface by magnetic force.

2. Description of the Related Art Conventionally, a projection screen that is attached to a wall surface by magnetic force is known. As an example of such a projection screen, a columnar frame is provided on each of two opposite sides of the screen, and when storing, the screen is wound around one frame as an axis, and a notch provided in the other frame is used. The structure which hold | maintains the shape after winding is disclosed by hooking the fastener pulled out from the edge part of the flame | frame used as a shaft (for example, refer patent document 1 and patent document 2).
JP 2002-3084 A (paragraph 0021, FIG. 2, FIG. 4) JP 2002-284552 A (paragraph 0037, FIG. 8, FIG. 14)

  However, the above conventional technique has a problem that a complicated structure including an elastic member such as a coil spring is required in order to realize a projection screen that can be easily stored and deployed.

  In order to solve the above-mentioned problem, a first aspect of the present invention is a flexible projection screen that is attached to a wall surface by magnetic force, and includes a magnet sheet and an optical image projection side of the magnet sheet. A reflection layer that is formed on the surface and reflects an optical image; a shaft that is attached to one side of the magnet sheet; and a shaft that is provided on the same surface as the reflection layer on the other side opposite to one side of the magnet sheet to which the shaft is attached; When the magnetic sheet is wound with the reflective layer inside, the magnetic sheet is wound around the shaft by being attracted by the magnetic force to the outside of the magnetic sheet already wound around the shaft. A projection screen including a winding fixing part to be fixed is realized. Thereby, a projection screen excellent in ease of storage and handleability can be realized with a simple configuration at low cost.

  In the above projection screen, both sides of the magnet sheet are magnetized, and the winding fixing part is provided so as to extend outward from the reflection layer on the other side facing one side of the magnet sheet to which the shaft is attached. It may be composed of a surface exposed to the reflective layer side. Thereby, since a member for exclusive use is not used for a winding fixing part, cost reduction of a projection screen is realizable.

  In the above projection screen, the winding fixing portion may be a magnet that is provided separately from the magnet sheet and has a surface magnetic flux density higher than the surface magnetic flux density of the magnet sheet. Thereby, the stability of fixation in the state which wound up the projection screen improves. Further, the area of the winding fixing portion can be smaller than when a part of the magnet sheet is exposed to form the winding fixing portion. Accordingly, it is possible to increase the ratio of the reflection sheet to the projection screen.

  The projection screen may further include a flange that is provided at both ends of the shaft and regulates the position of the end of the projection screen when the projection screen is wound up. Thereby, when winding up the projection screen, both ends of the projection screen can be easily aligned.

  In the above projection screen, the shaft and the flange may be formed as separate parts and may be configured in combination with each other. As a result, the production process is simplified compared to the case where the shaft and the flange are integrally formed, and the production cost is reduced as a whole.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  1 and 2 show a configuration of a projection screen 100 according to a first example of the present embodiment. 1 is a plan view when the projection screen 100 is developed, and FIG. 2 is a side view of the projection screen 100 of FIG. FIG. 3 is a view showing a state in which the projection screen 100 of this embodiment is wound around the winding shaft 30. The projection screen 100 of the present embodiment is a flexible projection screen that is attracted and held by a magnetic force on a wall surface made of a ferromagnetic material such as iron. The projection screen 100 can be stored compactly by being wound around the winding shaft 30. Hereinafter, in a state where the projection screen 100 is unfolded as shown in FIG. 1, the surface on which the optical image is projected is referred to as a projection surface of the projection screen 100, and the surface opposite to the projection surface is referred to as the rear surface of the projection screen 100. .

  The projection screen 100 forms a rectangle such as a rectangle in the unfolded state. The projection screen 100 includes a single-sided magnet sheet 20, a reflection sheet 10, a winding shaft 30, a flange 60, a drawer side frame 50, and a hard magnet 40. The single-sided magnet sheet 20 is a flexible sheet-like magnet in which magnet powder such as a ferrite magnet is mixed with rubber or resin, and is provided on the rear surface of the projection screen 100. The single-sided magnet sheet 20 has N poles and S poles alternately and repeatedly on one side attached to the wall surface. That is, the magnetization pattern of the single-sided magnet sheet 20 is single-sided multipolar magnetization in which the wall surface is magnetized. The single-sided magnet sheet 20 is provided so as to extend more than the reflection sheet 10 on both sides in the longitudinal direction.

  The reflection sheet 10 is provided on the projection surface side of the single-sided magnet sheet 20. The reflection sheet 10 is an example of a reflection layer, and constitutes a projection surface that projects an optical image from an optical engine such as a liquid crystal projector. The reflection sheet 10 is, for example, a white resin film that is matted so as to diffusely reflect a projected optical image. Alternatively, the reflection sheet 10 is a reflection having a large number of fine serrated irregularities extending in the horizontal direction so as to efficiently reflect an optical image projected from the lower front or upper front of the projection screen 100 toward the front of the projection screen 100. It may be a sheet. The reflective sheet 10 is attached to the single-sided magnet sheet 20 with an adhesive sheet or an adhesive. Alternatively, the reflective layer may be formed by applying a white resin on the projection surface side of the single-sided magnet sheet 20 instead of the reflective sheet 10.

  The winding shaft 30 is attached to one side of the single-sided magnet sheet 20 extended from the reflection sheet 10. The winding shaft 30 is an example of the shaft of the present invention. As shown in FIG. 3, the projection screen 100 can be accommodated in a compact manner by winding the reflection sheet 10 and the single-sided magnet sheet 20 around the winding shaft 30. In this case, the winding shaft 30 is wound with the reflective sheet 10 facing inward and the single-sided magnet sheet 20 facing outward.

  When the single-sided magnet sheet 20 is wound around the winding shaft 30, the drawing-out side frame 50 and the hard magnet 40 are on the same surface as the reflective sheet 10 on the side that is finally wound, that is, the side facing the winding shaft 30. Is provided. For example, it is attached to the same surface as the reflection sheet 10 at the edge portion of the single-sided magnet sheet 20 provided to extend from the reflection sheet 10 on the side facing the winding shaft 30. The drawer side frame 50 is a resin or metal columnar member, and is fixed to the short side of the single-sided magnet sheet 20 on the side opposite to the winding shaft 30. The drawer-side frame 50 maintains the shape of the end of the single-sided magnet sheet 20 in a straight line, thereby improving the handleability of the projection screen 100 when the projection screen 100 is installed on the wall surface and stored. The reflection sheet 10 may be provided up to the side surface of the drawer side frame 50.

  A hard magnet 40 is provided on the upper surface of the drawer side frame 50, that is, the surface opposite to the single-sided magnet sheet 20. The hard magnet 40 of this embodiment is provided at a plurality of locations on the drawer side frame 50. The drawer side frame 50 may have a recess that is substantially the same as the outer shape of the hard magnet 40, and the hard magnet 40 may be held in the recess. In this case, it is desirable to provide the upper surface of the drawer side frame 50 and the upper surface of the hard magnet 40 substantially flush with each other. When the projection screen 100 is accommodated, the upper surface of the hard magnet 40 is wound around the projection screen 100 by being magnetically attracted to the back surface of the single-sided magnet sheet 20 wound around the winding shaft 30 and facing outward. It fixes in the state wound up by the axis | shaft 30. FIG. The hard magnet 40 is an example of a winding fixing part of the present invention. According to the present embodiment, the projection screen 100 that is easy to store and easy to handle can be realized with a simple configuration.

  When the projection screen 100 is wound around the take-up shaft 30, the magnetic force of the hard magnet 40 resists the repulsive force that the reflecting sheet 10 and the single-sided magnet sheet 20 try to return to the flat state, and causes the end of the single-sided magnet sheet 20 to move. It has a magnetic force that can be surely attracted to the outside of the single-sided magnet sheet 20 that has already been wound around the winding shaft 30. As the hard magnet 40, for example, a magnet having an attractive force for fixing the projection screen 100 in a state of being wound around the winding shaft 30 from a ferrite magnet, an alnico magnet, a rare earth magnet, or the like is used.

  The hard magnet 40 of the present embodiment is provided separately from the single-sided magnet sheet 20 and has a surface magnetic flux density higher than the surface magnetic flux density of the single-sided magnet sheet 20. Thereby, when winding up the projection screen 100, the hard magnet 40 can stably fix the end of the single-sided magnet sheet 20 with a narrower width. Therefore, the ratio of the area of the reflective sheet 10 on the projection surface side of the single-sided magnet sheet 20 can be increased. In the above example, the single-sided magnet sheet 20 is provided so as to extend more than the reflective sheet 10 on both sides in the longitudinal direction. However, the single-sided magnet sheet 20 and the reflection sheet 10 may be formed with the same dimension in the longitudinal direction. In this case, the single-sided magnet sheet 20, the reflection sheet 10, the drawer-side frame 50, and the hard magnet 40 are stacked in this order from the back side of the projection screen 100 on the side facing the winding shaft 30. The means for fixing each layer is an adhesive or an adhesive sheet.

  The flange 60 regulates the positions of both ends of the projection screen 100 when the reflecting sheet 10 and the single-sided magnet sheet 20 are wound around the winding shaft 30. Thereby, when accommodating the projection screen 100, both ends of the reflective sheet 10 and the single-sided magnet sheet 20 can be easily aligned. The flange 60 has a diameter that is slightly larger than the outer periphery of the wound single-sided magnet sheet 20 in a state where the reflecting sheet 10 and the single-sided magnetic sheet 20 are completely wound around the winding shaft 30. Thereby, both ends of the projection screen 100 can be reliably aligned.

  4 and 5 are views showing a state in which the winding shaft 30 is removed from the projection screen 100. FIG. The winding shaft 30 can be detached from the end of the single-sided magnet sheet 20 when the projection screen 100 is used. A shaft-side frame 52 is provided at the end of the single-sided magnet sheet 20 that is attached to the winding shaft 30. The shaft side frame 52 is a columnar member made of resin or metal, and is attached to the entire one side of the single-side magnet sheet 20 attached to the winding shaft 30. The shaft side frame 52 improves the handleability of the projection screen 100 in a state where the winding shaft 30 is removed by holding the shape of the end of the single-sided magnet sheet 20 in a straight line.

  On the side surface of the winding shaft 30, a slit 70 having a size capable of inserting the single-sided magnet sheet 20 to which the shaft-side frame 52 is attached is formed. When attaching the winding shaft 30 to the projection screen 100, the shaft-side frame 52 is inserted into the slit 70. Note that the projection screen 100 can be used by being attracted to a wall surface made of a ferromagnetic material even when the take-up shaft 30 is attached.

  FIG. 6 is a cross-sectional view showing another embodiment of the winding fixing portion. The position of the cross section corresponds to the left end in the cross sectional view of the projection screen 100 shown in FIG. The winding fixing part of the present embodiment is formed by laminating the single-sided magnet sheet 20, the reflection sheet 10, and the magnetic body 24 in this order from the back side of the projection screen 100. The single-sided magnet sheet 20, the reflection sheet 10, and the magnetic body 24 are bonded to each other by an adhesive layer 80. As another example, an adhesive sheet may be used instead of the adhesive layer 80. The magnetic body 24 is magnetized on the projection screen side of the projection screen 100, that is, the upper side in the direction of the drawing, and when the single-sided magnet sheet 20 and the reflection sheet 10 are wound around the winding shaft 30, the winding shaft 30 has already been wound. The projection screen 100 is fixed in a state where it is wound around the winding shaft 30 by being attracted to the back surface of the single-sided magnet sheet 20 that is wound around. As another example, the magnetic body 24 may be a ferromagnetic body that is not magnetized in advance. For example, a steel plate that is not magnetized in advance may be used as the magnetic body 24. Even in this case, when the single-sided magnet sheet 20 and the reflection sheet 10 are wound around the winding shaft 30, the magnetic body 24 is attracted to the back surface of the single-sided magnet sheet 20 that has already been wound around the winding shaft 30. By doing so, the projection screen 100 is fixed in a state of being wound around the winding shaft 30.

  The reflective sheet 10 may have a base material 12 and a plurality of prisms 14. The plurality of prisms 14 are a plurality of sawtooth reflecting surfaces formed on the projection surface side of the substrate 12. In the present embodiment, the plurality of prisms 14 are arranged without gaps with the ridge lines thereof facing in the horizontal direction when the projection screen 100 is in use. The prism 14 efficiently reflects an optical image projected from the lower front or upper front of the projection screen 100 toward the front of the projection screen 100. The height of the upper surface of the magnetic body 24 is preferably equal to or higher than the height of the upper surface of the prism 14. Thereby, when winding the single-sided magnet sheet 20 and the reflection sheet 10 around the winding shaft 30, the upper surface of the magnetic body 24 is reliably attracted to the backside of the single-sided magnet sheet 20. Further, the tip of the prism 14 is prevented from being crushed by the attractive force between the magnetic body 24 and the single-sided magnet sheet 20. For example, the thickness of each layer is about 300 μm for the single-sided magnet sheet 20 and the magnetic body 24, about 125 μm for the substrate 12, about 325 μm for the prism 14, and about 25 μm for the adhesive layer 80. In the example of such a thickness, the upper surfaces of the magnetic body 24 and the prism 14 have the same height.

  7 and 8 are diagrams showing a configuration of the projection screen 102 according to the second example of the present embodiment. FIG. 7 shows a plan view of the projection screen 102. FIG. 8 shows a state where the projection screen 102 is wound around the winding shaft 30. The projection screen 102 includes a double-sided magnet sheet 22 instead of the single-sided magnet sheet 20 of the projection screen 100. The double-sided magnet sheet 22 is magnetized on both sides. For example, the magnetization pattern of the double-sided magnet sheet 22 is double-sided multipole magnetization in which N-poles and S-poles are alternately repeated on both sides of the double-sided magnet sheet 22. Alternatively, the double-sided magnet sheet 22 may be configured by laminating the magnetized surfaces of the two single-sided magnet sheets 20 toward each other. The winding fixing part of the present invention is constituted by the hard magnet 40 and the drawer side frame 50 in the projection screen 100 of the first embodiment. On the other hand, the winding fixing part of the present embodiment extends outward from the reflection sheet 10 on the other side facing the one side to which the winding shaft 30 of the double-sided magnet sheet 22 is attached, and is exposed to the projection surface side. The double-sided magnet sheet 22 is configured. Other configurations are the same as those of the projection screen 100 of the first embodiment, and thus description thereof is omitted.

  When the reflective sheet 10 and the double-sided magnet sheet 22 are wound around the winding shaft 30 with the reflective sheet 10 inside, the projection surface of the stretched portion of the double-sided magnet sheet 22 is wound around the winding shaft 30 and faces outward. The projection screen 102 is fixed in a state of being wound around the winding shaft 30 by being attracted to the back surface of the double-sided magnet sheet 22 by magnetic force. The area of the stretched portion of the double-sided magnet sheet 22 is outside the double-sided magnet sheet 22 that has already been wound around the winding shaft 30 against the repulsive force that the reflective sheet 10 and the double-sided magnet sheet 22 try to return flat. It has an area that can reliably adsorb. According to the present embodiment, since a dedicated member is not used for the winding fixing portion, the projection screen 102 that is easier to assemble than the projection screen 100 of the first embodiment can be realized.

  FIG. 9 is an enlarged cross-sectional view of the winding shaft 30 and the flange 60. As shown in this figure, the winding shaft 30 and the flange 60 are formed and assembled as separate parts. The winding shaft 30 is, for example, a cylindrical member. The flange 60 has a fitting portion 62 and a flange portion 64. The fitting part 62 is fitted and fixed to the end part of the cylindrical winding shaft 30. The fitting part 62 may be fixed to the end of the winding shaft 30 by press fitting, or may be fixed by adhesion or welding. The collar portion 64 protrudes from the fitting portion 62 to both ends of the winding shaft 30 and is formed so as to protrude from the winding shaft 30 in the radial direction of the winding shaft 30. As described above, when the winding shaft 30 and the flange 60 are configured as separate parts, it is not necessary to manufacture a large mold for integrally molding the winding shaft 30 and the flange 60. Further, the cylindrical winding shaft 30 can be produced at low cost by resin extrusion molding or the like. In this case, the slit 70 is formed by cutting. The flange 60 can be formed at a low cost by using a mold that is significantly smaller than a mold that integrally forms the winding shaft 30 and the flange 60. Therefore, the cost of production can be reduced by configuring the winding shaft 30 and the flange 60 as separate parts.

  As is apparent from the above description, according to the present embodiment, the projection screen 100 that is easy to store and easy to handle can be realized with a simple configuration at low cost.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

A plan view of the projection screen 100 is shown. 2 is a side view of the projection screen 100. FIG. FIG. 3 is a diagram showing a state in which the projection screen 100 is being wound around the winding shaft 30. FIG. 3 is a view showing a state where a winding shaft 30 is removed from the projection screen 100. It is a figure which shows the winding shaft 30 removed from the projection screen. It is sectional drawing which shows the other Example of a winding fixing | fixed part. A plan view of the projection screen 102 is shown. FIG. 3 is a view showing a state in which the projection screen 102 is wound around the winding shaft 30. 3 is an enlarged cross-sectional view of a winding shaft 30 and a flange 60. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reflective sheet, 12 Base material, 14 Prism, 20 Single-sided magnet sheet, 22 Double-sided magnet sheet, 24 Magnetic body, 30 Winding shaft, 40 Hard magnet, 50 Drawer side frame, 52 Shaft side frame, 60 Flange, 62 Fitting part 64 collars, 70 slits, 80 adhesive layers, 100, 102 projection screen

Claims (5)

A flexible projection screen that is attached to a wall surface by magnetic force,
A magnet sheet,
A reflective layer that is formed on a surface of the magnet sheet on which an optical image is projected and reflects the optical image;
A shaft attached to one side of the magnet sheet;
When the magnet sheet is wound on the same surface as the reflective layer on the other side facing the one side of the magnet sheet to which the shaft is mounted, with the reflective layer as the center and the shaft as the center And a take-up fixing part that fixes the magnet sheet in a state of being wound around the shaft by being attracted by a magnetic force to the outside of the magnet sheet already wound around the shaft. The magnet sheet is magnetized on both sides,
The winding fixing portion is exposed to the reflective layer side of the magnet sheet provided to extend outside the reflective layer on the other side facing the one side of the magnet sheet to which the shaft is attached. The projection screen according to claim 1, comprising a plane.   The projection screen according to claim 1, wherein the winding fixing portion is a magnet that is provided separately from the magnet sheet and has a surface magnetic flux density higher than a surface magnetic flux density of the magnet sheet.   2. The projection screen according to claim 1, further comprising flanges provided at both ends of the shaft for regulating a position of an end portion of the projection screen when the projection screen is wound up.   The projection screen according to claim 4, wherein the shaft and the flange are formed as separate parts and configured in combination with each other.

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