JP2022128611A - Imaging device and method for preventing discontinuous change in projected brightness - Google Patents

Abstract

The present invention provides a video device and method for eliminating discontinuous changes in brightness at a portion of a screen with a magnetic sheet bonded to the back side that overlaps with a joint of a holding plate. [Solution] A video device includes a projector 1, a screen 2, and a holder 3 for installing the screen 2, in which the screen 2 has a magnet sheet 6 bonded to the back surface, and the holder 3 has a The dividing plate 4 is arranged and joined through the joint 5, and the dividing plate 4 has a means for attaching to the magnetic sheet 6, and furthermore, the image device is configured such that the dividing plate 4 has a means for attaching to the magnetic sheet 6. The magnetic sheet 6 is provided with a screen flattening means for flattening the unevenness of the magnetic sheet 6. [Selection diagram] Figure 1

Description

The present invention relates to a video device and a method for preventing a discontinuous change in the brightness projected on the video device, more specifically, a video device having a screen with a magnetic sheet bonded to the back surface and a screen on the screen surface of the video device. It relates to a method for preventing discontinuous changes in projected brightness.

A reflective screen has been developed so that an image projected by a projector can be viewed from the same direction as the projector. Demand for high-definition, large-screen video viewing via 5G smartphones is increasing, and 4K ultra-short-throw projectors that can be wirelessly connected to smartphones are already on the market. Against this background, there is a growing demand for a 60 to 120-inch large, high-brightness, high-resolution, and high-contrast reflective screen that can be used with ultra-short-throw projectors. For large reflective screens for ultra-short-throw 4K projectors, it is important to ensure flatness when viewed and to roll them up for transportation. (See Patent Documents 1 and 2).

Patent Document 1 discloses a reflective screen in which a flexible magnetic layer is laminated on the opposite side of the reflective screen sheet to the reflective surface. It is said that a sheet formed by dispersing ferromagnetic powder in a plastic resin is preferable.

Patent Document 2 describes a reflective screen (hereinafter also referred to as a spatial imaging iris surface system/reflective screen) used for a display of a spatial imaging iris surface system suitable for power saving. Alternatively, it is disclosed that a magnetic sheet is attached to the back surface of a reflective screen that can be applied to a larger display.

JP-A-11-72847 Japanese Patent No. 5971742

In the case of using a screen with a magnetic sheet pasted on the back surface, the magnetic sheet is attached to a holding body with a magnet. Since the screen has flexibility, there is an advantage that even a large screen can be rolled up and transported easily. On the other hand, the holding body can be easily transported by dividing it into a plurality of plates and joining them together at a viewing location. In this case, the holding body has the joint, and the screen has an overlapping portion with the joint. Further, even if the holder is an existing wall, if the wall material made of metal such as steel attached to the magnet is not integrated, the wall material can be joined together to form a joint. The screen will have an overlapping portion with the joint.

However, under the condition that the holding body formed by arranging a plurality of the dividing plates has the seam and the screen has a portion overlapping with the seam, the brightness is insufficient in the portion of the screen that overlaps the seam. It may appear to change continuously. There has been a problem of simply solving the phenomenon of discontinuous changes in brightness within the screen plane.

The present invention solves the above-mentioned problems and easily eliminates discontinuous changes in brightness at a portion of a screen having a magnetic sheet adhered to the back surface, which overlaps a joint of a holding body, and the image. It is an object of the present invention to provide a method for preventing discontinuous changes in brightness projected onto the screen surface of the device.

In order to solve the above problems, the present inventors have studied the causes and countermeasures for the discontinuous change in brightness, and as a result, have obtained the following knowledge.
(a) If there is a step at the joint of the holder, the step will affect the screen surface through the magnet sheet. Where the planarity of the holder is impaired by the step occurring in the cross-sectional direction of the holder, that is, when there is an edge that is a misaligned portion of the plane of the holder, the change in brightness projected on the screen occurs on both sides of the edge. A discontinuous phenomenon occurs.
(a) A discontinuous change in the brightness projected on the screen due to the step at the seam can be eliminated by aligning both sides of the seam of the holding body in close contact with each other.
(c) If there is a gap between the joints of the holding body, a magnetic force acts to pull the magnet sheet into the gap, and as a result, the screen surface is depressed in the gap, and both edges of the depression are aligned with the edge. This causes discontinuous changes in brightness projected on the screen.
(d) A discontinuous change in the brightness projected on the screen due to the gap at the joint can be eliminated by demagnetizing the area of the magnet sheet that overlaps the gap at the joint and the portions on both sides thereof.

The present invention has been made based on the above-described knowledge and further studies, and has the following gist and configuration.
[1] A video device comprising a projector, a screen, and a holder for installing the screen,
The screen has a magnet sheet attached to the back surface,
The holding body is formed by arranging and joining a plurality of partition plates via joints,
The partition plate has means for adhering to the magnet sheet,
The imaging apparatus further comprises screen flattening means for flattening unevenness of the magnetic sheet caused by steps and/or gaps at joints of the partition plates.
[2] The video device according to [1], wherein the partition plate is a composite plate having a structure in which thin plates attached to the magnetic sheet are arranged on both sides of a core material.
[3] The holding body has a frame framework, and the plurality of partition plates are arranged and joined to the frame framework on the flat surface of the frame of the frame framework so that the joints of the adjacent partition plates are in close contact with each other. The video device according to [1] or [2], characterized by:
[4] The screen flattening means has fasteners on the rear surfaces of the partition plates at the joints, and the fasteners consist of a high tensile strength adhesive tape or non-adhesive tape to be hung on the frame, and the adhesive The imaging device according to [3], characterized in that the tape or the non-adhesive tape is made of strong magnets or mechanical clamps for magnetically fixing both ends of the tape or non-adhesive tape to each partition plate.
[5] The partition plate is a wall material unit,
the holding body is a wall formed by arranging and joining a plurality of the wall material units via joints,
Any one of [1] to [4], wherein the screen flattening means has an area where the magnetic sheet is demagnetized in a range of 5 to 15 mm on both sides of the joint of the wall material unit. The video device according to any one of the above.
[6] A method for preventing discontinuous changes in the brightness projected on the screen on the surface of the screen using a video device comprising a projector, a screen, and a holder for installing the screen, comprising:
A magnet sheet is attached to the back surface of the screen,
a step of arranging and joining a plurality of division plates to the holding body via joints, and attaching the magnetic sheet to the division plates;
Further, a screen flattening step of flattening unevenness of the magnet sheet caused by steps and/or gaps at joints of the partition plates;
A method for preventing a discontinuous change in projected brightness on a screen surface, comprising:
[7] The division plate is a composite plate in which thin plates attached to the magnetic sheet are arranged on both sides of a core material. How to prevent continuous change.
[8] The holding body has a frame framework, and the plurality of partition plates are arranged and joined to the frame framework on the flat surface of the frame of the frame framework so that the joints of the adjacent partition plates are in close contact with each other. A method for preventing discontinuous changes in brightness projected on the screen on the screen surface according to [6] or [7].
[9] In the screen flattening step, the rear surface of the partition plate is fixed to the joint portion by a fixture, and the fixture consists of a high tensile strength adhesive tape or non-adhesive tape that is hung on the frame, and the adhesive The brightness projected on the screen on the screen surface according to [8], characterized by a strong magnet that magnetically fixes both ends of the tape or non-adhesive tape to each partition plate, or a mechanical clamp. How to prevent discontinuous changes.
[10] The dividing plate is a wall material unit, and the holding body is a wall body formed by arranging and joining a plurality of the wall material units via joints,
Any one of [6] to [9], wherein the screen flattening step demagnetizes a region of the magnetic sheet within a range of 5 to 15 mm on both sides of the joint of the wall material unit. 3. A method for preventing discontinuous changes in projected brightness on a screen surface according to claim 1.

Note that any one of the above [1] to [10] is more effective when the screen is a spatial imaging iris surface type/reflection screen in which the diffusion of the screen is smaller than that of a conventional screen. be.

Further, in any one of [1] to [10] above, it is more effective if the screen is a large screen with a diagonal of 60 inches or more.

According to the present invention, the unevenness of the screen surface caused by the joints of the screen that is attached to the holder having the joints by magnetic force can be eliminated by flattening the steps of the joints of the holders and/or demagnetizing the magnets near the joints. This can be solved by a simple method such as the above, and has an excellent effect of improving the workability and work efficiency of installing and adjusting a large screen.

1 is a schematic diagram showing an example of a video device according to the present invention; FIG. FIG. 4 is a cross-sectional view showing the structure of a partition plate; FIG. 4 is a schematic diagram showing an example of a holder; FIG. 4 is a schematic diagram showing a form of a fixture in the example of FIG. 3; FIG. 4 is a schematic diagram showing another example of a holder; FIG. 6 is a schematic diagram showing the form of a fixture in the example of FIG. 5; FIG. 4 is a schematic diagram showing an example in which the holder is an indoor wall. FIG. 4 is a schematic diagram showing an example of a demagnetized area; 1 is a schematic diagram showing an example of a spatial imaging iris plane type imaging apparatus according to the present invention; FIG. 1 is a cross-sectional view showing an example of a spatial imaging iris surface type/reflective screen according to the present invention; FIG. FIG. 4 is a schematic diagram showing unevenness of a magnet sheet caused by a step at a seam; FIG. 4 is a schematic diagram showing unevenness of a magnet sheet caused by gaps at joints;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. Further, in each drawing, the same or corresponding elements are denoted by the same reference numerals as appropriate, and overlapping descriptions are omitted as appropriate. Furthermore, it should be noted that the drawings are schematic, and the relative relationship of dimensions of each element may differ from the actual one. The mutual relationship between drawings may also include portions with different relative dimensional relationships and ratios.
[Video device]
The imaging apparatus of the present invention comprises, for example, a projector 1, a screen 2, and a holder 3 for installing the screen 2, as shown in FIG. 1 ([1] of the present invention). The projector 1 is means for projecting image light of a still image or a moving image onto the screen 2, and the configuration is not particularly limited as long as it is.

[screen]
The screen 2 receives the image light, diffuses the display image, reflects the image light toward the projector 1 side, and makes the display image visible on the projector 1 side.
In order to facilitate installation of the screen 2 on the holder 3, the screen 2 has a magnet sheet 6 bonded to the back surface ([1] of the present invention). It should be noted that the screen 2 is preferably a general rectangular planar body in accordance with the shape of the displayed image. In addition, the screen 2 is preferably a flexible sheet-like body that can be rolled into a cylindrical shape with the magnetic sheet 6 stuck together, from the viewpoint of portability in the case of a large-sized screen. The screen 2 to which the magnet sheet 6 is bonded is hereinafter also referred to as a magnet screen. The thickness of the magnetic screen is preferably about 1 mm. If the thickness is less than about 1 mm, the magnetic force is weak, and deformation such as wrinkles is likely to occur when it is attached to the holder, and there is a possibility that it will peel off from the holder. If it is thicker than about 1 mm, the screen 2 becomes heavy and impairs portability. Also, it is difficult to roll.

It should be noted that the screen 2 is preferably a spatial imaging iris surface type reflective screen (for example, see Patent Document 2) in that the image has high brightness, high resolution, and high contrast even in a bright room. In the spatial imaging iris surface method, as shown in FIG. 9, the distance a from the projector 1 to the reflective surface of the screen 2 with the focal length f and the distance b from the reflective surface to the eyes of the viewer are 1/a+1/b=1/f (where a and b each have an allowable range of ±10%) so that the viewer's eye position is positioned on the spatial imaging iris plane 30. It is a method of As shown in FIG. 10, for example, the screen used in this system comprises a flat substrate 35 and a layer covering the front side of the substrate 35, and the surface shape of the layer allows diffusion in the horizontal and vertical directions within the plane. A surface shape dependent anisotropic diffusion layer 39 with different angles and a layer covering the back side of the substrate 35 are formed, and the back side of the layer has a lens surface 36a and a non-lens surface 36b and is convex toward the back side of the layer. A lens layer 36 with a focal length f, a lens surface 36a of the lens layer 36, or , a layer covering the lens surface 36a and the non-lens surface 36b, the layer covering the reflective layer 37 made of a metal with a high reflectance (reflectance of 70% or more), and the back side of the reflective layer 37, It has a protective layer 38 that protects the layer 37 and a magnetic sheet 6 bonded to the back side of the protective layer 38 . The magnet sheet 6 is attached to the rear surface of the screen 2 with a double-sided adhesive tape (not shown).
It is more effective if the screen 2 is a large screen with a diagonal size of 60 inches or more. This is because if the diagonal size is less than 60 inches, even if the holding body 3 is a one-piece body without joints 5, it is easy to carry.

[Holder and division plate]
On the other hand, the holding body 3 is formed by arranging and joining a plurality of partition plates 4 via joints 5 in terms of portability in the case of a large screen. The partition plate 4 has a means for adhering to the magnet sheet 6 ([1] of the present invention) so that it can be easily spread out and fixed. Here, "adheres to the magnet sheet 6" means to adhere to the magnet sheet 6 by a magnetic force generated by being magnetized by the magnetism of the magnet sheet 6. FIG.

The partition plate 4 is made of a composite plate 9 having a structure in which thin plates 7 attached to a magnetic sheet 6 are arranged on both sides of a core material 8, for example, as shown in FIG. ]). A material for the thin plate 7 includes a metal material such as steel. The thickness of the thin plate 7 is preferably 1 mm or less. As a material of the core material 8, a polymeric material such as foamed polyethylene can be used. The thickness of the core material 8 is preferably 1 to 2 mm.

As the holding body 3, the dividing plate 4 is used as a wall material unit made of metal such as steel, and a plurality of such wall material units are arranged and joined via joints 5 to form a flat surface of an existing wall or the like. A shaped structure may be used ([5] of the present invention).

Further, in the present invention, one of the "means for adhering to the magnet sheet" of the partition plate 4 and the "magnet sheet" on the rear surface of the screen 2 may be replaced with the other. This also allows the screen 2 to be easily fixed to the holder 3 . However, in the form after replacement, the "means for adhering to the magnet sheet" on the back surface of the screen 2 is highly flexible due to the ease of rounding the screen 2, and the "magnet sheet" of the partition plate 4 is the holder. Due to the difficulty of deformation of 3, poor flexibility is preferable.

[Screen Flattening Means]
Further, the imaging apparatus of the present invention includes screen flattening means (hereinafter simply referred to as flattening means) for flattening unevenness of the magnetic sheet 6 caused by steps and/or gaps of the joints 5 of the partition plates 4. ([1] of the present invention).
Without the flattening means, when a plurality of partition plates 4 are arranged and joined through joints 5 to form a holder 3, as schematically shown in FIG. may occur. If there is a step 40 , the magnetic force 50 generated between the holding member 3 and the magnet sheet 6 causes the magnetic sheet 6 to closely adhere to the holding member 3 following the step 40 . are generated, and the surface of the screen 2 is also uneven following this. This unevenness causes a discontinuous change in brightness projected on the screen as described above.

In addition, in a state without the flattening means, when a plurality of partition plates 4 are arranged and joined via joints 5 to form a holder 3, as schematically shown in FIG. 42 may occur. If the gap 42 exists, the magnetic force 50 generated between the holder 3 and the magnet sheet 6 causes the magnet sheet 6 to come into close contact with the partition plate 4, and the upper part of the gap 42 is drawn into the gap 42 and collapses. As a result, the screen 2 also collapses, and the irregularities caused by this collapse cause discontinuous changes in the brightness projected on the screen. The value of this step (dimension in the direction parallel to the plate thickness direction of the partition plate) is also related to the diffusion characteristics of the screen 2, but in the screen of the spatial imaging iris surface system, even if it is as small as several 100 microns, A discontinuous change in the projected brightness occurs.

As one embodiment, the flattening means includes the frame framework and the fixture (hereinafter referred to as the first flattening means), which are means for arranging, joining and fixing the partition plate 4 so as not to create a step 40 and a gap 42 at the joint 5 . (also referred to as a reforming means), and is provided in the holding body 3 .

In addition, in a situation where an existing planar structure such as a wall made of metal such as steel is used as the holder 3, if there is a gap between the joints of the wall, the person carrying the screen may dismantle the wall. It is difficult to reconstruct and eliminate seam gaps. In such a case, the flattening means, as another embodiment, does not form unevenness that causes a discontinuous change in the brightness projected on the screen at the gap 42 on the surface of the screen 2 on the magnet sheet 6. Thus, the magnet sheet 6 is provided with the gap 42 of the magnet sheet 6 and its periphery as a demagnetized area (hereinafter also referred to as second flattening means).

It should be noted that there is also a state in which the gap is generated at the joint regardless of whether the holder 3 having the first flattening means is used. In such a case, the peripheral portion of the joint 5 of the magnet sheet 6 may be demagnetized as the second flattening means.
[First flattening means (including the frame framework)]
As the first flattening means, the holding body 3 is provided with a frame 10, for example, as shown in FIG. Moreover, it is preferable that the partition plates 4 are arranged and joined so that the joints 5 of the adjacent partition plates 4 are in close contact with each other ([3] of the present invention). Here, "the joints 5 of the adjacent partition plates 4 are brought into close contact with the flat surface of the frame 10A of the frame framework 10" means that the ends of the joints 5 of the adjacent partition plates 4 are brought into close contact with each other and The close joint 5 means a state in which the rear surfaces of the partition plates 4 on both sides are in close contact with the flat surface of the frame 10A of the frame framework 10 .
This makes it possible to easily suppress the generation of steps and gaps at the joints 5 of the holders 3 .

FIG. 3 shows an example of a state in which "joints 5 of the adjacent partition plates 4 are in close contact with the flat surface of the frame 10A of the frame framework 10". Although the longitudinal direction of the flat surface is parallel to the extending direction of the joint 5, as another example, as shown in FIG. The longitudinal direction of the joint 5 may be perpendicular to the extending direction.
The frame 10A, which is a unit member of the frame framework 10, must have a flat surface that is in close contact with the rear surface of the partition plate 4 on both sides of the joint 5, and must be a long object that is lightweight, has appropriate rigidity, and is easy to assemble. are preferred, and examples thereof include wooden squares and aluminum or plastic square pipes.

[First flattening means (including the fixture)]
As shown in FIGS. 3 to 6, for example, the first flattening means preferably has a fixture 12 on the back surface of the partition plate 4 at the joint 5 ([4] of the present invention). As a result, the holder 3 can be easily held in a state without steps and gaps. As the fixture 12, a high tensile strength adhesive tape 14 (see FIG. 4(a)) or a non-adhesive tape 18 (see FIG. 6(a)) to be hung on the frame 10A, and the adhesive tape 14 or the non-adhesive tape 18 A strong magnet 20 (see FIG. 4(a) and FIG. 6(a)) having both ends magnetically fixed to each partition plate 4 is preferable from the viewpoint of ease of attachment. Here, "high tensile strength" means that the tensile stress is strong, so that it is difficult to stretch even if it is strongly pulled from both ends. Tape (commonly referred to as adhesive tape and non-adhesive tape) is a tape whose base material is polyester fiber or film having excellent tensile strength. A fiber tape based on polyester fiber, which is commercially available for packaging, can also be used as the fixture 12 . Further, the term "strong magnet" means that the stronger the magnetic force, the better. However, if the strength of the magnet is too strong, it will be difficult to peel off the tape after it has been adhered. The fixture 12 may be a mechanical clamp 16 (see FIGS. 4(b) and 6(b)).

[Second flattening means (the demagnetized region)]
In the screen flattening means, for example, as shown in FIGS. 7 and 8, the partition plate 4 (composite plate 9 consisting of a core material 8 and thin plates 7 attached to the magnetic sheets 6 on both sides thereof) is made of steel or the like. and the holder 3 is a wall WB formed by arranging and joining a plurality of wall material units WU via joints 5, the second flattening means is , and a demagnetized area 22 in a range of 5 to 15 mm on both sides of the joint 5, 5 of the wall material unit WU ([5] of the present invention). This is because the area portion 22 is a combined area of the gap 42 of the seams 5 and 5 and the ranges S1 and S2 on both sides thereof, and the ranges S1 and S2 (specifically, the length of the ranges S1 and S2 in the direction perpendicular to the seam 5). depth) are both 5 to 15 mm. As a result, the magnetic force 50 that draws the magnet sheet 6 into the gap 42 is lost in the region 22, and the screen 2 immediately above the gap 42 is flattened. If the ranges S1 and S2 are less than 5 mm, the influence of the magnetic force on the ends of the gap 42 cannot be eliminated, and if it exceeds 15 mm, the S1 and S2 become too wide, which may hinder the flattening of the screen. It is from. As a degaussing method, there is a method of scanning a degaussing target portion (region 22) with a degaussing head (not shown) consisting of an electromagnet for applying an AC magnetic field.
In addition, the present invention uses a video device (see FIG. 1) having a projector 1, a screen 2, and a holder 3 for installing the screen 2 to reduce the discontinuity of brightness projected on the screen 2 surface. A method (hereinafter, also referred to as a method of the present invention) for preventing such a change, wherein a magnetic sheet 6 is attached to the back surface of the screen 2, and the holding body 3 holds a plurality of partition plates 4 through joints 5. A step of arranging and joining and attaching the magnet sheet 6 to the partition plate 4, and further, unevenness of the magnet sheet 6 caused by a step 40 and/or a gap 42 at the joint 5 of the partition plate 4 (see FIGS. 11 and 12). ) ([6] of the present invention).

In the method of the present invention, the dividing plate 4 is preferably a composite plate 9 in which thin plates 7 attached to the magnetic sheet 6 are arranged on both sides of a core material 8 (see FIG. 2, [7] of the present invention). .

Further, in the method of the present invention, the holding body 3 is provided with a frame 10, the plurality of partition plates 4 are attached to the frame 10 on the flat surface of the frame 10A of the frame 10, and the adjacent partition plates 4 are attached to the flat surface of the frame 10A. It is preferable to arrange and join the ends so that they are closely attached at the joint 5 (see FIGS. 3 and 5, [8] of the present invention).

Further, in the method of the present invention, the screen flattening step includes fixing the rear surface of the partition plate 4 to the location of the joint 5 with a fixture 12. The fixture 12 has a high tensile strength to be hung on the frame 10A. It consists of an adhesive tape 14 or a non-adhesive tape 18 and a strong magnet 20 for magnetically fixing both ends of the adhesive tape 14 or non-adhesive tape 18 to each partition plate 4, or a mechanical clamp 16 (Fig. 4, See 6. [9]) of the present invention is preferred.

Further, in the method of the present invention, the dividing plate 4 is a wall material unit WU made of metal such as steel, and the holding body 3 is arranged by arranging a plurality of wall material units WU via joints 5. The wall WB is formed by joining, and the screen flattening process demagnetizes the region 22 of the magnet sheet 6 in the range of 5 to 15 mm on both sides of the joint 5, 5 of the unit WU of the wall (Fig. See 7 and 8. [10]) of the present invention is preferred.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.
[Example 1]
An imaging device having the form shown in FIG. 1 was manufactured. A general-purpose ultra short focus 4K projector was used as the projector 1 . The screen 2 is the spatial imaging iris surface type reflective screen (100 inches 16:9, thickness 0.5 mm) shown in FIG. It was made into a magnet screen. The imaging device has a configuration in which a spatial imaging iris surface 30 is formed as shown in FIG.

As shown in FIG. 1, the holder 3 was designed to be a rectangular body with vertical and horizontal margins on the outside of the overlapping portion with the screen 2, but it was made the same size as the screen so that there would be no vertical and horizontal margins on the outside. good too. A raw plate having the same shape as the rectangular body is horizontally divided into three (substantially divided into three) to form three rectangular division plates 4, and the three division plates 4 are extended in the vertical direction. A holder 3 was formed by arranging and joining them via joints 5 (horizontal end surfaces of the partition plates 4). The partition plate 4 had the configuration shown in FIG. 2, and was formed by arranging steel thin plates 7 (0.5 mm thick) to which magnetic sheets 6 were attached on both sides of a core material 8 (2 mm thick) made of expanded polystyrene.

When arranging and joining the partition plates 4 , as shown in FIG. 3 , the ends of the adjacent partition plates 4 are arranged so as to be in close contact with each other at the joints 5 , and the frame framework 10 is brought into close contact with the rear surface of the partition plates 4 . The frame framework 10 is made by assembling square pipes made of aluminum (the cross-sectional outer periphery is 30 mm square), and is brought into close contact with the four sides of the holding body 3, and the screen flattening means (the first flattening means in this example) As a result, the frame 10A was brought into close contact with both side portions along the joint 5 of the partition plate 6, and these close contact portions were joined. Next, the back surface of the partition plate 4 was fixed to the joint 5 with the fixture 12 to obtain Example (1) of the present invention.

Here, as shown in FIG. 4(a), the fixture 12 consists of an adhesive tape 14 made of a general-purpose polyester fiber base material with high tensile strength that is hung over the frame 10A, and both ends of the adhesive tape 14 are attached to the respective partition plates 4 by magnetic force. A general-purpose bar-shaped neodymium magnet was used as the strong magnet 20 to be fixed.

As a result, in the example (1) of the present invention, it is possible to prevent the generation of steps and gaps at the joints 5 in the holding body 3, and the surface of the screen 2 placed on the holding body 3 is flattened, so that when viewing an image, the above-mentioned No discontinuous change in brightness projected on the screen was observed.

On the other hand, as a comparative example (1), a form (not shown) in which the screen flattening means is eliminated from the above-described inventive example (1). More specifically, in FIG. 3, the fixture 12 is removed and the frame 10A is moved to a position where it does not overlap the joint 5. As shown in FIG.

As a result, in the comparative example (1), as shown in FIG. The surface of the installed screen 2 overlapped with the step was uneven, and when an image was viewed, the brightness projected on the screen changed discontinuously.
[Example 2]
A magnetic screen similar to that of Example 1 was installed with a wall WB as shown in FIG. The magnetic screen installation portion of the wall WB is formed by arranging and joining three wall material units WU as partition plates 4 (similar to the first embodiment) with joints 5 between adjacent wall material units WU. A gap 42 (about 10 mm wide and about 5 mm deep) was present between the joints 5 and 5 . Here, the width is the dimension in the direction orthogonal to the joint 5, and the depth is the dimension in the direction parallel to the thickness direction of the partition plate 4. As shown in FIG.

Therefore, before installing the magnetic screen on the wall WB surface, as shown in FIG. And the area of the magnet sheet 6 overlapping the area 22 in the range of S1 and S2 on both sides (in this example, both S1 and S2 have a width of 5 to 15 mm) is scanned from the surface of the magnet sheet 6 with a general-purpose rod-shaped neodymium magnet to demagnetize. As a result, the demagnetized region 22 is obtained as the present invention example (2).

As a result, in Example (2) of the present invention, the surface of the screen 2 was maintained in a flat state without irregularities due to gaps, and no discontinuous change in the brightness projected on the screen occurred when an image was viewed. .

On the other hand, as a comparative example (2), in the present invention example (2), the demagnetization is not performed and the demagnetized region portion 22 is not provided.

As a result, in the comparative example (2), as shown in FIG. 12, the portion of the magnet sheet 6 that overlaps the gap 42 sinks into the gap 42, causing irregularities on the surface of the screen 2, and when viewing an image, A discontinuous change in brightness projected on the screen appeared.

1 Projector 2 Screen 3 Holder 4 Division plate 5 Joint 6 Magnet sheet 7 Thin plate attached to magnet sheet 8 Core material 9 Composite board 10 Frame framework 10A Frame 12 Fixture 14 Adhesive tape 16 Mechanical clamp 18 Non-adhesive tape 20 Strong magnet 22 area part 30 spatial imaging iris surface 35 substrate 36 lens layer 36a lens surface 36b non-lens surface 37 reflective layer 38 protective layer 40 step 42 gap 50 magnetic force WU wall material unit WB wall body

Claims (10)

A video device comprising a projector, a screen, and a holder for installing the screen,
The screen has a magnet sheet attached to the back surface,
The holding body is formed by arranging and joining a plurality of partition plates via joints,
The partition plate has means for adhering to the magnet sheet,
The imaging apparatus further comprises screen flattening means for flattening unevenness of the magnetic sheet caused by steps and/or gaps at joints of the partition plates. 2. The imaging device according to claim 1, wherein the partition plate is composed of a composite plate having a structure in which thin plates attached to the magnetic sheet are arranged on both sides of a core material. The holding body has a frame framework, and the plurality of partition plates are arranged and joined to the frame framework on the flat surface of the frame of the frame framework so that the joints of the adjacent partition plates are in close contact with each other. 3. The video device according to claim 1 or 2. The screen flattening means has fasteners on the rear surfaces of the partition plates at the joints, and the fasteners are high tensile strength adhesive tape or non-adhesive tape to be hung on the frame and the adhesive tape or non-adhesive tape. 4. The imaging device according to claim 3, wherein the adhesive tape is made of strong magnets or mechanical clamps for magnetically fixing both ends of the adhesive tape to the respective partition plates. The partition plate is a wall material unit,
the holding body is a wall formed by arranging and joining a plurality of the wall material units via joints,
5. The screen flattening means has a region where the magnet sheet is demagnetized in a range of 5 to 15 mm on both sides of the joint of the wall material unit. 3. The imaging device according to the paragraph. A method for preventing discontinuous changes in brightness projected on a screen surface using a video device comprising a projector, a screen, and a holder for installing the screen, comprising:
A magnet sheet is attached to the back surface of the screen,
a step of arranging and joining a plurality of division plates to the holding body via joints, and attaching the magnetic sheet to the division plates;
Further, a screen flattening step of flattening unevenness of the magnet sheet caused by steps and/or gaps at joints of the partition plates;
A method for preventing a discontinuous change in projected brightness on a screen surface, comprising: 7. The discontinuous change in the brightness projected on the screen on the screen surface according to claim 6, wherein the dividing plate is a composite plate in which thin plates attached to the magnetic sheet are arranged on both sides of a core material. how to prevent The holding body has a frame framework, and the plurality of partition plates are arranged and joined to the frame framework on a flat surface of the frame of the frame framework so that the joints of the adjacent partition plates are in close contact with each other. 8. A method for preventing discontinuous changes in projected brightness on a screen surface according to claim 6 or 7. In the screen flattening step, the back surface of the partition plate is fixed to the joint by a fixture, and the fixture is a high tensile strength adhesive tape or non-adhesive tape that is hung on the frame, and the adhesive tape or non-adhesive tape. 9. The discontinuity of the brightness projected on the screen on the screen surface according to claim 8, characterized in that it consists of strong magnets or mechanical clamps that magnetically fix both ends of the adhesive tape to each partition plate. How to prevent change. The partition plate is a wall material unit, and the holding body is a wall body formed by arranging and joining a plurality of the wall material units via joints,
10. The screen flattening step demagnetizes a region of the magnetic sheet within a range of 5 to 15 mm on both sides of the joint of the wall material unit. A method for preventing discontinuous changes in the brightness projected on the screen on the surface of the screen.

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