JP3063866B2 - Close contact mounting device for lens sheet and flat plate and supporting method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device for superimposing and simultaneously supporting a lens sheet and a flat plate and supporting the same, and more particularly, to a thin projection screen having relatively low rigidity, which is brought into close contact with the flat plate. TECHNICAL FIELD The present invention relates to a device suitable for flattening and mounting and a method of supporting the device. INDUSTRIAL APPLICABILITY The present invention is effectively used particularly for mounting a transmission type or reflection type screen for a display screen such as a projection television or an overhead projector.

[0002]

2. Description of the Related Art In recent years, a projection screen having a lenticular lens or a Fresnel lens as a rigid element has been used in order to obtain a desired image display performance. Recently, particularly for the purpose of improving the resolution, the pitch of the lenticular lens and the pitch of the Fresnel lens are gradually reduced, and the screen itself is required to be thinner. Since such a thin screen has low rigidity, it is necessary to provide a means for supporting the outer periphery so as to maintain a predetermined planar shape.

Conventionally, as means for maintaining this planar shape,
For example, a method in which a frame having rigidity is disposed around the frame and four corners of the frame and four corners of the sheet-like screen are connected by a tension spring (Japanese Utility Model Laid-Open No. 59-121646), (See Japanese Utility Model Laid-Open No. 60-154940 and Japanese Utility Model Laid-Open No. 61-112329) in which the opposite two sides and / or four sides of the sheet-like screen are connected to the opposite two sides and / or four sides of the sheet-like screen by a spring or the like having a tensile force. No., Japanese Utility Model Application Laid-Open No. 61-11233
No. 0, Japanese Utility Model Application Laid-Open No. 61-123331, Japanese Utility Model Application
-69229, Japanese Utility Model Laid-Open No. 1-93885, and Japanese Utility Model Laid-Open No. 1-117634). Also, for example, a frame having rigidity is arranged around the periphery, the outer periphery of the sheet-shaped screen is fixed to the frame, and the sheet surface near the outer periphery of the screen is elastically moved from a direction perpendicular to the sheet surface by a pressing member. Method of applying pressing force
Japanese Patent No. 302338) has been proposed.

[0004]

However, in the above-described method in which the four corners of the screen are pulled, the sides of the screen are easily deformed in a bow shape due to the local pulling force at the four corners, and the image display performance near the outer periphery is deteriorated. Cheap. In the method of pulling the side portion of the screen, when the screen expands and contracts due to a change in ambient environment conditions, the direction of the pulling force by the spring or the like changes due to the rigidity of the frame body, thereby causing distortion in the screen. And the image display performance tends to deteriorate. Also, even in a method in which the pressing member elastically applies a pressing force from a direction perpendicular to the sheet surface, when the screen expands and contracts due to a change in ambient environment conditions, the position of the pressing member is fixed, and the contact position with the screen is also fixed. As a result, distortion is generated on the screen, and the image display performance is liable to deteriorate. Further, when a pressing force is applied elastically from a direction perpendicular to the sheet surface, there is a disadvantage that the thickness of the apparatus increases. Further, in the above-mentioned conventional system, the width of the frame-shaped structure provided around the optically effective surface of the screen is wide, and there is a design limitation.

In view of the above-mentioned problems of the prior art, the present invention has a simple structure, is easy to mount, and does not reduce the image display performance even when the screen expands and contracts due to a change in ambient environment conditions. It is an object of the present invention to provide a device capable of increasing a ratio of a target effective surface, particularly a thin lens sheet, a transparent front plate, and a lenticular lens sheet, which are attached in close contact with expansion and a rational support method thereof. It is.

[0006]

The lens sheet and the flat sheet are elastically engaged with the folded support engagement portions on the respective edges and the opposite engagement portions of a single leaf spring, respectively. The basic principle of the present invention is to allow the elastic force of the leaf spring to simultaneously act between the flat plate and the leaf spring so as to be slidable in the side direction and to extend each of the lens sheet and the flat plate.

That is, the present invention is an apparatus for extending and supporting a thin lens sheet and another flat plate while maintaining flatness in a state where the thin lens sheet and another flat plate are superimposed on each other. It has a bearing engaging part whose edge is bent at a predetermined width at an acute angle, and has a resilient engaging part formed opposite to the bearing engaging part of the lens sheet and the flat plate, and a part thereof. A plate spring made of an elastic plate material for simultaneously applying elastic forces in the extending direction and the pressing direction to the lens sheets; attaching the fixed portion of the plate spring to a rigid member, and Are elastically engaged with the respective bearing engagement portions of the lens sheet and the flat plate . In here, as the material of the leaf spring, metallic steel or aluminum, etc., also available various plastic materials, both folding of the plate bending or profile extrusion, drawing or the like can be applied for this purpose.

As specific examples of the plastic material, various resin materials such as polycarbonate resin, hard vinyl chloride resin, polypropylene, polyethylene, polystyrene, ABS and AS can be used for this purpose.

[0009]

FIG. 3 to FIG. 5 are comparative study diagrams of a support structure between a lens sheet and a leaf spring, which were made prior to embodying the present invention. FIG. 3 shows an example of a support structure suitable for the present invention, and FIGS. 4 and 5 show examples of a support structure not suitable for the present invention. Although these figures compare the relationship between the lens sheet 1 and the leaf spring 3, the same can be said between the flat plate such as the lenticular lens sheet 2 and the leaf spring 3.

3 (a) to 3 (d) show that the elastic force of the leaf spring 3 acting on the bearing engagement portion of the lens sheet 1 simultaneously increases the extension tension of the lens sheet 1 and the pressing force against the flat plate. It absorbs expansion and contraction of the lens sheet based on environmental changes in the surroundings, and is in close contact with a front plate such as a lenticular lens sheet or a transparent plate that is placed on the lens sheet 1 so that image display performance is deteriorated. I will not let you. As shown in the figure, the tip shape of the leaf spring 3 does not necessarily have to have an acute cross section.

On the other hand, as shown in FIGS. 4 (a) and 4 (b), when the spring force of the leaf spring 3 has a component force in the direction of pulling the lens sheet 1, the component force in the extension direction acts. Then, even if the expansion and contraction of the lens sheet 1 due to a change in the surrounding environment is absorbed, the lens sheet 1 may be peeled off from the front plate, and a space may be formed between the two to lower the image display performance.

In the case where the edge of the lens sheet 1 is bent as shown in FIG. 5 and the portion is used as a leaf spring 3, as shown by arrows in FIGS. When the rotational force acts on the boundary between the lens sheet 1 and the lens sheet 1, the surface of the lens sheet 1 is partially curved and undulates, so that the planar shape cannot be maintained and the front plate is disposed. Causes a partial gap between the two, which further reduces the image display performance.

[0013]

EXAMPLES The following specifically described with reference to exemplary embodiments of the equipment of the present invention.

FIG. 1 shows an example in which the lens sheet extension mounting device of the present invention is applied to a support portion of a screen for a 45-inch projection TV. In this embodiment, the extension support structure of the lens sheet and the flat plate of the present invention is shown. This is applied to the frame body 5 and supports the Fresnel lens sheet 1 and the lenticular lens sheet 2 as a flat plate in close contact. The 45-inch projection TV has PE on the front.
A Fresnel lens sheet 1 made of T (polyethylene terephthalate) and a lenticular lens sheet 2 are tightly fitted and fixed to a frame 5. Opening edge 51 of frame 5
A fixing member 51 for supporting and fixing one side of the leaf spring 3 at a predetermined distance in the depth direction from the opening edge 51 at a portion to which the device of the present invention is applied.
Can be attached with screws 6. The portion to which the present invention is applied does not need to be the entire circumference of the frame 5,
Only two edges adjacent in both the vertical and horizontal directions are sufficient, and the corresponding edges of the lens sheet 1 and the flat plate may be directly or indirectly fixed to the remaining two edges.

This embodiment is an example in which a thin Fresnel lens sheet 1 and a lenticular lens sheet 2 are used in an overlapping manner. Of course, another simple flat plate is combined with the Fresnel lens sheet 1 or the lenticular lens sheet 2. It can also be applied to large projection screens with the simplest mounting structure. In the figure, reference numeral 3 denotes a leaf spring which is a main component of the present invention.

The Fresnel lens sheet 1 is a film-shaped rectangular sheet made of PET (polyethylene terephthalate) and has cutouts at four corners as shown in FIG. It is folded and set. This folded portion forms the bearing engaging portion 11 in the present invention. The lenticular lens sheet 2 is made of the same material as the Fresnel lens sheet 1 and is a rectangular rigid sheet having a slightly larger size and thickness than the Fresnel lens sheet 1, and as shown in FIG. Similarly, four corners are cut out, and the four edges are each folded and set at an acute angle in the same direction.

FIG. 8 shows a modification of the bearing engaging portions 11 and 21 of the lens sheets 1 and 2, and is a structural example effective when the lens sheets 1 and 2 are made of extremely thin PET resin. When the bearing engaging portions 11 and 21 are easily deformed, the engaging engaging members 9 made of polycarbonate resin or metal such as aluminum formed so as to surround the engaging portions 11 and 21 are attached to the bearing engaging portions 11. , 21.

The leaf spring 3 is formed by bending a central portion of a strip-shaped plate made of polycarbonate resin into a U-shape in a length direction at two places at a desired interval, and forming both edges thereof substantially in a Z-shape.
Then, it is bent inwardly and further bent inwardly at an acute angle with both edges facing each other to form a whole channel-like shape, and a pair of elastic engaging portions 31 facing each other is formed at the center of the inside. The central flat portion of the U-shaped bent portion is fixed to the frame 5 with screws or the like. In addition to using the above-described bending process of the band-shaped plate material, using the above-described various-shaped extruded products of plastics and metal materials is excellent in mass productivity and more rational. FIG. 9 shows an example of a cross-sectional shape of the extruded product.

The leaf spring 3 may be formed from a single plate material equal to the length of each edge of the Fresnel lens sheet 1 and the lenticular lens sheet 2, but these may be used separately. is there. In order for the Fresnel lens sheet 1 and the lenticular lens sheet 2 to be supported by the leaf spring 3, the two lens sheets 1, 2
The respective elastic engaging portions 31 of the leaf spring 3 are engaged with the supporting engaging portions 11 and 22 of the lens sheets 1 and 2 such that the supporting engaging portions 11 and 22 of the lens sheets 1 are back-to-back.

In this embodiment, a thin Fresnel lens sheet 1 (FL) and a lenticular lens sheet 2 (L
The specifications of T) and the leaf spring 3 are as follows.

[Specification of FL] PE having a thickness of 125 microns
The four corner cutouts of a film-shaped Fresnel lens sheet having an average thickness of 100 μm, a Fresnel lens pitch of 100 μm, and a focal length of 1 m formed on one surface of the T film by the 2P method are set by folding back with a width of 5 mm, respectively.
The external dimensions were as follows. External dimensions: Width W ₁ = 940 mm Height H ₁ = 700 mm [LT specifications] Four-side cutouts on a single-sided lenticular lens sheet formed by hot-plate press molding a 3 mm-thick methacrylic resin plate containing an organic light diffusing agent. 5 mm between each
It was set by folding back at the width of, and the external dimensions were as follows. External dimensions: Width W ₂ = 940 mm Height H ₂ = 700 mm [Specification of leaf spring] A polycarbonate resin sheet having a thickness of 0.3 mm and a width of 100 mm is 880 mm and 640 mm in length.
mm was prepared one by one, each was bent into the shape shown in the figure, and its free edges were bent inward at an acute angle of 7 mm each and fixed in a cold state.

Using these members and assembling them as shown in FIG. 1 in particular, a 45-inch projection T
In the screen for V, the thin Fresnel lens sheet 1 was also kept flat and the lenticular lens 2 adhered well. A frame 5 incorporating the two lens sheets 1 and 2 is
No abnormality was found in both of them even when the heat cycle of 60 ° C. × 2H and -20 ° C. × 2H was repeated 10 times.

In the above embodiment, the leaf spring 3 is formed by bending and setting one elastic plate material. However, two elastic plate materials are bent and set symmetrically, and the plate spring 3 shown in FIG. The center of the spring 3 cut in the length direction can be abutted and fixed to the frame 5, and in this case, the interval between the opposing elastic engaging portions 31 can be easily adjusted.

FIG. 7 shows another embodiment of the lens sheet mounting structure according to the present invention, in which two elastic plates are used as the plate springs 3 and one edge of each rectangular plate in the longitudinal direction is bent at an acute angle. An example in which the elastic engaging portions 31 are bent at approximately 90 ° in the length direction in the width direction of the two rectangular plate members in a state where the elastic engaging portions 31 face each other, and the entire cross section is configured to be substantially L-shaped. It is. In this example, the elastic engagement portions 31 are fixed to the entire inner surface of the frame 5 in a state where the elastic engagement portions 31 abut against each other, and the two elastic engagement portions 31 are attached to the respective support engagement portions 11 of the Fresnel lens sheet 1 and the lenticular lens sheet 2. The two lens sheets 1 and 2 are closely supported by elastically engaging.
In this embodiment as well, the Fresnel lens sheet 1 is maintained in a flat shape as well as in each of the above embodiments, and is well adhered and supported on the lenticular lens sheet 2, and in this state, it can withstand the heat cycle test sufficiently. Was.

[0025]

According to the present invention, as described in detail in the text, the mounting is easy with a simple structure, and furthermore, the flat spring having a unique shape allows a gentle expansion over the entire thin lens sheet and flat plate. The directional force is applied and the two are brought into close contact.Even if the lens sheet and the flat plate expand or contract due to changes in temperature, humidity, etc., each is absorbed by the elastic force of the leaf spring, and the lens sheet is always absorbed. Is kept closely spread while maintaining the planar shape. Further, the present invention can be implemented by simply processing an inexpensive material easily, so that the economical and practical effects are high.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a typical embodiment of the present invention.

FIG. 2 is a partially enlarged cross section of a mounting portion in the embodiment.

FIG. 3 is a partial cross-sectional view showing an example of an elastic engagement structure conforming to the present invention.

FIG. 4 is a partial cross-sectional view showing an example of an elastic engagement structure unsuitable for the present invention.

FIG. 5 is a partial sectional view showing another example of the inappropriate elastic engagement structure of the present invention.

FIG. 6 is a perspective view showing the overall configuration of a lens sheet and a flat plate, which are constituent members of the present invention.

FIG. 7 is a partially omitted cross-sectional view showing a modified example of the leaf spring and an example of a mounting structure thereof.

FIG. 8 is a partial perspective view showing a modified example of a bearing engaging portion in the lens sheet.

FIG. 9 is a sectional view showing another example of a sectional shape of the leaf spring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 (Fresnel) lens sheet 2 Lenticular lens sheet 3 Leaf spring 4 Stapler needle 5 Frame 6 Screw 9 Engagement reinforcing material 11, 21 (returned) support engagement part 31 Elastic engagement part 52 Opening edge

Claims (2)

(57) [Claims] An apparatus for extending and supporting a thin lens sheet and another flat plate while maintaining flatness in a state where the thin lens sheet and another flat plate are superimposed, wherein at least two adjacent edges of the four edges of the lens sheet and the flat plate are predetermined. It has a bearing engagement portion bent at an acute angle, has an elastic engagement portion formed opposite to engage the bearing engagement portion of the lens sheet and the flat plate, and partially has a fixed portion. A leaf spring made of an elastic plate material for simultaneously applying elastic forces in a stretching direction and a pressing direction to each of the lens sheets, wherein the fixed portion of the leaf spring is attached to a rigid member, and each of the elastic engaging portions is the lens. A device for closely attaching a lens sheet and a flat plate, wherein the lens sheet and the flat plate are elastically engaged with respective support engaging portions of the sheet and the flat plate. 2. A front end cross section of the elastic engaging portion of the leaf spring is formed at an acute angle, and a portion of the elastic engaging portion which is closest to the surface of the lens sheet body in the bearing engaging portion is supported by the tip end. 5. The contact mounting device according to claim 1, wherein the rotational force is minimized.