JPH0540314A - Mounting method and supporting method for lens sheet - Google Patents

Abstract

PURPOSE:To provide the inexpensive device for spreading and supporting a lens sheet which allows simple mounting with a simple construction, prevents image display performance from degrading even at the time of expanding or contracting a screen by the change of surrounding cnvironment condition, is of a thin type, and allows a larger ratio of the optical effective area of the screen to be taken. CONSTITUTION:At least one edge side of the opposite edge sides of the lend sheet 1 are elastically engaged with supporting and engaging parts 11 which are folded back at a sharp angle at a prescribed width and leaf springs 3 which have an elastic engaging part 31 on one edge side, has a fixing part 32 on the other edge side, and consists of a polycarbonate resin, etc., to simultaneously act the elastic force in a spreading direction and a pressing direction on the lens sheet at the time of the elastic engagement. In addition, the fixing parts of the leaf springs are mounted to a rigid member 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device and a supporting method for a lens sheet, and more particularly to a mounting device and a supporting method suitable for mounting a thin projection screen having a relatively low rigidity in a flat state. INDUSTRIAL APPLICABILITY The present invention is effectively used particularly for mounting a transmissive or reflective screen for a display screen such as a projection television or an overhead projector.

[0002]

2. Description of the Related Art Recent projection screens have used lenticular lenses or Fresnel lenses as rigid elements in order to obtain desired image display performance. In recent years, especially 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 thin. Since such a thin screen has low rigidity, a means for supporting the outer periphery so as to maintain a predetermined planar shape is required.

Conventionally, as the means for maintaining the planar shape,
For example, a method of arranging a frame having rigidity and connecting the four corners of the frame and the four corners of the sheet-like screen with tension springs (Japanese Utility Model Laid-Open No. 59-121646) or the frame. 2 and / or 4 sides of the sheet-shaped screen and the opposite 2 sides and / or 4 sides of the sheet-like screen are connected by a spring or the like having a tensile force (Japanese Utility Model Publication No. 60-154940, Japanese Utility Model Publication No. 61-112329). Publication No. SHO 61-11233
No. 0, No. 61-12331, No. 1
No. -69229, Japanese Utility Model Laid-Open No. 1-93885, and Japanese Utility Model Laid-Open No. 1-117634) are proposed. Further, for example, a frame having rigidity is arranged around the frame, 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 pressed from a direction perpendicular to the sheet surface by a pressing member. Method of applying pressing force
No. 302,338) is also proposed.

[0004]

However, in the method of pulling the four corners of the screen, the side portions of the screen are easily deformed in a bow shape due to the local pulling forces at the four corners, and the image display performance in the vicinity of the outer periphery is deteriorated. Cheap. Further, in the method of pulling the side portion of the screen, when the screen expands and contracts due to changes 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, which causes distortion in the screen. However, the image display performance tends to deteriorate. Even when the pressing member elastically applies a pressing force from a direction perpendicular to the sheet surface, when the screen expands or contracts due to changes in ambient environmental conditions, the position of the pressing member is fixed and the contact position with the screen is also fixed. As a result, the screen is likely to be distorted and the image display performance is likely to be deteriorated. Further, when the pressing force is elastically applied from the direction perpendicular to the sheet surface, there is a drawback that the thickness of the device becomes large. Further, in the conventional method as described above, the width of the frame-shaped structure portion provided around the optically effective surface of the screen is wide, and there is a design restriction.

In view of the above-mentioned problems of the prior art, the present invention has a simple structure and is easy to install, and does not deteriorate the image display performance even when the screen expands or contracts due to changes in ambient environment conditions. It is an object of the present invention to provide a lens sheet mounting device that can take a large ratio of effective surfaces and a rational supporting method thereof.

[0006]

[MEANS FOR SOLVING THE PROBLEMS] By engaging a folded-back bearing engaging portion on the edge of a lens sheet with an elastic engaging portion of a leaf spring, the lens sheet and the leaf spring are slidable in the lateral direction and the lens The basic principle of the present invention is to apply the elastic force of the leaf spring in the sheet extending direction.

That is, the present invention is a device for expanding and supporting a thin lens sheet while maintaining its flatness, wherein at least one of the opposite edges of the lens sheet is folded back by a predetermined width at an acute angle, and a bearing engaging portion is provided. While having an elastic engaging portion that engages with the bearing engaging portion of the lens sheet on one edge,
And a leaf spring made of an elastic plate material that has a fixing portion on the other edge and applies elastic forces to the lens sheet in the stretching direction and the pressing direction at the same time, and the fixing portion of the leaf spring is attached to a rigid member. In addition, a method of spreading and supporting a thin lens sheet by closely adhering to another plane plate while maintaining flatness, including a vector component in a direction in which the edge of the lens sheet is pressed against the plane plate,
Moreover, the elastic force in the expansion direction is applied to the edge of the lens sheet without applying a rotational force orthogonal to the sheet surface to a part of the lens sheet.

As a result of comparative examination of various products available as the material for the leaf spring, it was found that the polycarbonate resin sheet is the best as the leaf spring material made of the plastic material in the following points. Can be cold-folded and does not whiten. There is a wide range where spring force can be exerted by elastic deformation.

[0009]

3 to 5 are comparison and examination views relating to the support structure between the lens sheet and the leaf spring, which were made prior to carrying out the present invention. FIG. 3 shows an example of a bearing structure compatible with the present invention, and FIGS. 4 and 5 show an example of a bearing structure not applicable to the present invention.

3 (a) to 3 (d), the elastic force of the leaf spring 3 acting on the bearing engaging portion of the lens sheet 1 has both the extension tension and the pressing force of the lens sheet 1 at the same time. In addition, it absorbs the expansion and contraction of the lens sheet due to changes in the surrounding environment and also adheres well to the front plate such as the lenticular lens sheet or the transparent plate that is installed in superposition on the lens sheet 1, which may deteriorate the image display performance. Absent.
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, when the spring force of the leaf spring 3 has a component force in the direction of pulling the lens sheet 1 as shown in FIGS. 4 (a) and 4 (b), the component force in the extension direction acts. Even if the expansion and contraction of the lens sheet 1 due to changes in the surrounding environment is absorbed, the lens sheet 1 may be peeled off from the front plate, and a space may be created between the two to reduce the image display performance.

Further, when the edge of the lens sheet 1 is bent as shown in FIG. 5 and the portion is used as the leaf spring 3, the leaf spring portion is indicated by an arrow in FIGS. When a 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 undulated to maintain a planar shape, and the front plate is arranged. Causes a partial gap between the two, further lowering the image display performance.

[0013]

EXAMPLES The apparatus and method of the present invention will be specifically described below based on representative examples.

1 and 2 show a first embodiment of the present invention, FIG. 1 is an exploded perspective view of the constituent members of the present invention, and FIG. 2 is a partially enlarged view of the engaged state of each member. FIG. The embodiment is an example in which a thin Fresnel lens sheet 1 and a lenticular lens sheet 2 are used in an overlapping manner, and can be applied to a large projection screen having the simplest attachment structure. In the figure, reference numeral 3 indicates a leaf spring which is a main component of the present invention.

The Fresnel lens sheet 1 is a film-like rectangular sheet made of PET (polyethylene terephthalate), has cutouts at its four corners, and the four edges are set by folding the same in the same direction into two acute angles. It
This folded portion forms the support engagement portion 11 in the present invention.
The lenticular lens sheet 2 is made of the same material as the Fresnel lens sheet 1, and the Fresnel lens sheet 1
It is a rectangular rigid sheet with slightly larger dimensions and thickness. The leaf spring 3 is formed by folding a strip-shaped plate material made of a polycarbonate resin into two pieces in the lengthwise direction thereof, and at the same time, slightly folding back the free end edge in a direction with a predetermined dimension so as to form two engaging portions. Of these, the engaging portion that elastically engages the support engaging portion 11 of the Fresnel lens sheet 1 is the elastic engaging portion 31 of the present invention, and the other engaging portion is the fixing portion 32 of the present invention. I am doing it. Each of the leaf springs 3 may be formed of a single plate member having the same length as each edge of the Fresnel lens sheet 1, but the plate springs 3 may be divided and used.

In this embodiment, a thin Fresnel lens sheet 1 (FL) and a lenticular lens sheet 2 (L) are used.
The specifications of T) and the leaf spring 3 are as follows. [FL Specifications] For the four corner cutouts of a film-like Fresnel lens sheet having an average wall thickness of 100 microns formed by the 2P method on one side of a 125-micron-thick PET film, a Fresnel lens pitch of 100 microns, and a focal length of 1 m. Each of them was folded back and set with a width of 5 mm, and the external dimensions were as follows. External dimensions: Horizontal width W ₁ = 920 mm Vertical width H ₁ = 680 mm [LT specifications] A single-sided lenticular lens sheet having external dimensions formed by hot-pressing a methacrylic resin plate with a thickness of 3 mm containing an organic light diffuser. Obtained. External dimensions: Width W ₂ = 940 mm Height H ₂ = 700 mm [Specifications of leaf spring] 0.3 mm thick, 64 mm wide polycarbonate resin sheet with lengths of 880 mm and 640 m
Two sheets each of m were prepared, each of which was folded in two in the length direction at the center of the width, and the overlapping free end edge was bent inward at an acute angle of 7 mm and cold-fixed. Further, a stapler needle 4 was attached in the vicinity of the same edge along the two-fold edge.

When these members were assembled as shown in FIG. 2, the thin Fresnel lens sheet 1 was kept in a flat plane and was well adhered to the lenticular lens sheet 2. This is 60 ℃ × 2H, -20 ℃ × 2H
No abnormality was found when 10 heat cycles were repeated for 10 cycles.

FIG. 6 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 type projection TV. In this embodiment, the lens sheet extension support structure of the present invention is applied to the frame body 5. Is applied to support the Fresnel lens sheet 1, and the lens sheet 1 is attached to the lenticular lens sheet 2 as the front plate.
It is a close contact. As shown in FIG. 7, the 45-inch type projection TV has a lenticular lens sheet 2 made of PET as a front plate, which is fitted and fixed to the frame body 5 on the front surface. A screw stopper 51 is formed on the inner surface of the frame 5 at a predetermined interval, and an opening edge 52 of the screw stopper 51 protrudes inward to form a frame-shaped space 53 between the screw stopper 51 and the screw stopper 51. ing.

The lenticular lens sheet 2 in this embodiment is manufactured with the same specifications as in the first embodiment,
The surface of the upper edge is 3 mm thick and has a width of 10 m and a length of 200.
Three 3 mm holding members 21 for hanging are adhered. The lenticular lens sheet 2 is an upper space 5 of the frame body 5.
In the state where the suspension holding member 21 is fitted into the screw 3, the seat plate member 7 attached to the screw fixing portion 51 by the screw 6 and the opening edge 52 are sandwiched and fixed.

The Fresnel lens sheet 1 and the leaf spring 3 are manufactured with the same specifications as in the first embodiment, and the upper bearing engaging portion 11 of the Fresnel lens sheet 1 and the elastic engaging portion 31 of the leaf spring 3 are engaged with each other. At the same time, the fixing portion 32 of the leaf spring 3 is hooked and fixed on the upper edge of the seat plate member 7. Further, the lower bearing engaging portion 11 of the Fresnel lens sheet 1 is
Separately manufactured by being fitted to the lower edge of the lenticular lens sheet 2, the entire cross section is approximately U-shaped, and the thickness is 0.2 mm.
The one end of the engaging member 8 made of the aluminum plate is engaged by fitting. The right and left edges of the Fresnel lens sheet 1 are attached in the same manner, but the engagement and attachment with the leaf springs 3 may be performed on all the top, bottom, left and right edges.
Alternatively, one of the upper, lower, left and right edges may be attached via the leaf spring 3.

In the 45-inch projection TV screen thus assembled, the flat surface of the thin Fresnel lens sheet 1 was kept clean and was well adhered to the lenticular 2. This is the same as the first embodiment, 60 ℃ ×
When the heat cycle of 2H and -20 ° C x 2H was set as one cycle and 10 cycles were repeated, there was no abnormality.

FIG. 8 shows another embodiment of the lens sheet mounting structure of the present invention, in which a material having a large spring force is used as the leaf spring 3, and only one edge in the lengthwise direction of the rectangular plate material is folded back so that the elastic member is elastic. The mating portion 31 is used, and the other opposite edge is fixed to the fixing portion 3.
2, the fixing portion 32 is fixed to the inner wall surface of the frame body 5 with a screw 6, and the elastic engagement portion 31 is elastically engaged with and supported by the support engagement portion 11 of the Fresnel lens sheet 1. is there. Also in this embodiment, the Fresnel lens sheet 1 is maintained in a planar shape and is well adhered to and supported by the lenticular lens sheet 2 in the same manner as in each of the above-described embodiments, and this state can sufficiently withstand the heat cycle test. It was

FIG. 9 shows still another embodiment of the lens sheet mounting structure of the present invention, in which the rectangular leaf spring 3 is used.
The fixing portion 32 and the elastic engaging portion 31 are bent in a bellows shape, and also in this embodiment, the flat shape of the Fresnel lens sheet and the adhesion to the front plate can be closely followed according to changes in the surrounding environment. Maintained and securely supported the lens sheet.

FIG. 10 shows a modification of the bearing engaging portion of the lens sheet. This is an example of a structure effective when the lens sheet is made of an extremely thin PET resin.
When 1 is easily deformed, an engagement reinforcing member 9 made of a metal such as a polycarbonate resin or aluminum formed so as to surround the engagement portion 11 may be attached to the support engagement portion 11.

[0025]

According to the present invention, as described in detail in the text, the leaf spring having a simple structure and easy mounting, and having a unique shape, exerts a gradual force in the spreading direction on the entire surface of the thin lens sheet. Will be applied, so
Even if the lens sheet expands and contracts due to changes in temperature and humidity, the lens sheet is always stretched in a flat shape. Further, since the present invention can be carried out by simply processing an inexpensive material, the economical and practical effects are high.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing a mounting state of the embodiment.

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

FIG. 6 is a partially omitted cross-sectional view showing another embodiment of the present invention.

FIG. 7 is a partial exploded perspective view of a 45-inch projection TV in which the device of the embodiment is incorporated.

FIG. 8 is a cross-sectional view showing a modified example of the leaf spring and an example of its mounting structure with a part omitted.

FIG. 9 is a sectional view with a part omitted showing another modified example of the leaf spring and an example of its mounting structure.

FIG. 10 is a partial perspective view showing a modified example of the bearing engagement portion of the lens sheet that is a component of the present invention.

[Explanation of symbols]

 1 (Fresnel) lens sheet 2 Lenticular lens sheet 3 Leaf spring 4 Stapler needle 5 Frame body 6 Screw 7 Seat plate material 8 Engagement member 9 Engagement reinforcement member 11 (Folded) bearing engagement part 21 Suspension holding member 31 Elastic engagement Part 32 Fixed part 51 Screw stop part 52 Opening edge 53 Space

Claims (6)

[Claims] 1. A device for expanding and supporting a thin lens sheet while maintaining its flatness, wherein at least one of opposite edges of the lens sheet has a support engagement portion folded back at an acute angle for a predetermined width, A plate made of an elastic plate material that has an elastic engaging portion that engages with the bearing engaging portion of the lens sheet, has a fixing portion on the other edge, and applies elastic forces in the stretching direction and the pressing direction to the lens sheet at the same time. A lens sheet attachment device, comprising: a spring, wherein the fixing portion of the leaf spring is attached to a rigid member. 2. The leaf spring having a thickness of 0.1 mm or more and 1 mm
The lens sheet mounting device according to claim 1, wherein the lens sheet mounting device comprises the following polycarbonate resin sheet. 3. The lens sheet mounting device according to claim 1, wherein the support engagement portion of the lens sheet is formed of at least a polycarbonate resin sheet. 4. The lens according to claim 1, wherein the leaf spring is formed by folding a strip-shaped body made of an elastic plate material in two in the width direction and fixing the vicinity thereof in a dot shape along the folding portion. Seat mounting device. 5. The elastic engaging portion of the leaf spring is formed to have a sharp tip cross section, and the tip of the elastic engaging portion is used to support the portion of the bearing engaging portion closest to the surface of the lens sheet body. 5. The lens sheet mounting device according to claim 1, wherein the rotational force is minimized. 6. A method of adhering a thin lens sheet to another flat plate while keeping the flatness thereof while keeping the flatness, and including a vector component in a direction in which an edge of the lens sheet is pressed against the flat plate. A method for supporting a lens sheet, which comprises applying an elastic force in a stretching direction to an edge of the lens sheet without applying a rotational force orthogonal to the sheet surface to a part of the sheet.