WO2007132597A1

WO2007132597A1 - Method of mounting sheet member and method of manufacturing frame with sheet member for surface light source

Info

Publication number: WO2007132597A1
Application number: PCT/JP2007/056765
Authority: WO
Inventors: Naoki Tsujiuchi; Osamu Watanabe
Original assignee: Toray Industries, Inc.
Priority date: 2006-05-12
Filing date: 2007-03-29
Publication date: 2007-11-22
Also published as: TW200801725A; JPWO2007132597A1

Abstract

A method of suitably mounting a sheet member onto a surface light source. This method is characterized in that at least one sheet member and a frame for a surface light source are pulled and joined together on at least one side of the frame by using elastic bodies, and then, the sheet member is stretched over the frame for the surface light source while being kept in a tensed state.

Description

Specification

TECHNICAL FIELD The present invention relates to a method for mounting a sheet member and a method for manufacturing a surface light source frame with a sheet member.

The present invention relates to a method for attaching a sheet member to a surface light source frame of a surface light source used for various illumination devices, display devices, and the like. In particular, the sheet member is preferably attached to the surface light source frame of the liquid crystal display device. Furthermore, a manufacturing method of a surface light source frame with a sheet member to which a sheet member is attached using this method, a surface light source using the surface light source frame with a sheet member obtained by this manufacturing method, and this surface light source are used. The present invention relates to a liquid crystal display device. Background art

[0002] Liquid crystal display devices are used in various applications such as notebook computers and mobile phone devices, televisions, monitors, car navigation systems, and the like. The liquid crystal display device has a surface light source (backlight unit) built in, and the display is performed by controlling the light of the surface light source power through the liquid crystal cell. The characteristic required for this surface light source is to make the entire screen shine brightly and uniformly, not just as a light source that emits light.

[0003] The structure of the surface light source can be roughly divided into two.

[0004] One is a method called a side light type surface light source. This is a method mainly used for, for example, notebook computers that are required to be thinner and smaller, and is characterized by using a light guide plate as a basic configuration. In the case of a sidelight type surface light source, a fluorescent tube is installed on the side surface of the light guide plate, the light is incident on the side force guide plate, and the light is propagated throughout the surface while totally reflecting inside the light guide plate. The surface of the light guide plate is made to function as a surface light source by detaching a part of the total reflection condition force and radiating the front light force of the light guide plate. In the case of a sidelight type surface light source, in addition to these components, a reflection film that has a function of reflecting and reusing light leaking from the back surface of the light guide plate, and making light emitted from the front surface of the light guide plate uniform Other types of optical films are used, such as diffusion sheets and prism sheets that improve frontal brightness.

[0005] Another method is called a direct-type surface light source. This is a system that is preferably used for TV applications that require large size and high brightness, and does not use a light guide plate. It features a hollow structure in which fluorescent tubes are arranged directly in the back of the screen. By arranging a plurality of linear or partially linear fluorescent tubes in the back of the screen, it is possible to handle a large screen and to ensure sufficient brightness.

[0006] With the help of a fluorescent tube installed at the back of the screen, which is also a feature, uneven brightness in the screen

(Brightness unevenness) occurs. In other words, the space between the adjacent bright fluorescent tubes becomes dark just above the multiple fluorescent tubes arranged side by side (tube unevenness). For this reason, in order to eliminate this tube unevenness in the direct type surface light source, a milky white plate having extremely strong light diffusibility is installed on the upper side of the fluorescent tube to make the screen uniform (Patent Document 1). The milky white plate is a light diffusing plate having an acrylic resin or a polycarbonate resin in which fine particles are dispersed. The milky white plate eliminates tube unevenness and makes the screen uniform. However, because it diffuses strongly, the total light transmittance is low and the light utilization efficiency deteriorates. As a result, the required frontal brightness is insufficient.

[0007] Therefore, on the milky white plate, a diffusion sheet that exhibits a light collecting effect in the front direction while diffusing light isotropically is installed (Patent Document 2). This diffusion sheet is a sheet in which a diffusion layer containing fine particles such as organic cross-linking particles is formed on a base sheet, and is an optical film that exhibits directivity in the front direction to some extent, unlike a milky white plate.

[0008] In addition to these, the direct type surface light source includes a reflection film that reflects light emitted backward from the fluorescent tube, a prism sheet for improving the light condensing property as necessary, and a liquid crystal cell. A polarization separation sheet that can improve the light utilization efficiency and improve the brightness by reflecting and reusing the polarized light component absorbed by the polarizing plate incorporated in is also incorporated.

[0009] FIG. 2 shows a general configuration of the direct type surface light source as described above. A fluorescent tube 3 is arranged in a hollow portion formed inside the housing 1, and a milky white plate 5 is installed above the fluorescent tube 3. The milky white plate 5 has a thickness of 2 to 3 mm and has rigidity. By placing it on the upper part of the housing 1, the milky white plate 5 is used as a support body for optical sheets such as a diffusion sheet 6 and a prism sheet 7 that are further stacked on top. It is functioning.

[0010] Thus, it is necessary for a direct-type surface light source to achieve both a uniform screen and high brightness, and in order to eliminate tube unevenness originating from the fluorescent tube at the back of the screen, A white board is used. However, the milk white plate used to eliminate tube unevenness has low total light transmittance and uses light. ineffective. In addition, a very inefficient configuration is adopted in which the light scattered too much by the milky white plate is condensed again using a diffusion sheet. Furthermore, as mentioned earlier, the milky white plate is 2 to 3 mm thick, which hinders thinning.

[0011] Therefore, in recent years, there has been a strong demand for the development of a function-integrated sheet that integrates the functions of a milky white plate while being a thin film.

[0012] However, if the milky white plate is removed except that it functions as a support for a plurality of optical sheets while the inner surface of the direct type surface light source is hollow, the optical sheets are placed in a predetermined place. It is not possible to hold it. Therefore, it is necessary to fix these optical sheets to a frame such as a casing or frame of a surface light source.

[0013] Although the optical sheet can be fixed to the frame of the surface light source with only an adhesive or a screw, this method causes thermal expansion and contraction of the optical sheet over time and stagnation due to its own weight. As a result, the uniformity of in-plane light as a surface light source deteriorates.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-29091

Patent Document 2: Japanese Patent Laid-Open No. 2001-324607

Disclosure of the invention

Problems to be solved by the invention

[0014] Therefore, in view of the background of the prior art that works, the present invention provides a method for suitably attaching a sheet member used for a surface light source to a surface light source frame, and further, a surface light source with a sheet member using the forceful mounting method. It is intended to provide a method for manufacturing a frame.

Means for solving the problem

[0015] The present invention employs one of the following configurations in order to solve the problem.

(1) The surface member is held in a tensioned state by pulling at least one sheet member and the surface light source frame with an elastic body on at least one side of the surface light source frame. A method for attaching a sheet member to be extended to a light source frame.

(2) The sheet member is provided with an opening A and the surface light source frame is provided with an opening a, and the elastic member is passed through the opening A to be fitted into the opening a to expand the sheet member. The sheet member mounting method according to 1). (3) The seat member attachment method according to (2), wherein the opening A has a dimension such that a gap is formed in a part between the opening A and the elastic body during expansion.

(4) The sheet member according to any one of (1) to (3), wherein the sheet member is held by fitting the sheet member to the surface light source frame at the opposite side of the side to be pulled using the elastic body. Mounting method.

(5) At the opposite side of the side to be pulled using the elastic body, the sheet member is provided with an opening B, a protrusion is provided on the surface light source frame, and the protrusion is passed through the opening B so that the sheet member is surfaced. The sheet member mounting method according to (4), wherein the sheet member is fitted to a light source frame.

(6) The seat member attachment method according to (5), wherein the opening B has a dimension such that a gap is formed in a part between the opening B and the protrusion during expansion.

(7) The seat member attachment method according to any one of (1) to (6), wherein the elastic body is a linear elastic body or a plate-like elastic body.

(8) The sheet member and the surface light source frame are provided with an elastic body on at least one pair of adjacent two sides of the surface light source frame, according to any one of (1) to (7). Sheet member mounting method.

(9) The surface light source frame according to any one of (1) to (8), wherein the surface light source frame is a surface light source frame for a liquid crystal display device, and the sheet member is an optical sheet for a liquid crystal display device. Seat member mounting method.

(10) A method for producing a surface light source frame with a sheet member, wherein the sheet member is attached to the surface light source frame by the method according to any one of (1) to (9).

(11) A surface light source using a surface light source frame with a sheet member obtained by the method according to (10).

(12) A liquid crystal display device using the surface light source according to (11).

The invention's effect

ADVANTAGE OF THE INVENTION According to this invention, even if a sheet | seat member does not have self-supporting property, the attachment method which extends a sheet | seat member on a surface light source frame of a surface light source without a crease can be provided. When this method is adopted as a method of attaching a surface light source used in a lighting fixture or a display device, particularly a liquid crystal display device, to a surface light source frame, the sheet member is stretched without stagnation, so that the uniformity of the surface light source is maintained. On the other hand, since the milky white plate as a support is not necessary, it is possible to reduce the thickness.

[0017] Further, according to a preferred aspect of the present invention, the sheet member can be expanded on the surface light source frame only by an elastic body without previously attaching a member such as a fixture to the sheet member. In addition to improving the performance, it is possible to save space for production equipment. Further, it is possible to provide a sheet member mounting method that does not cause bending or wrinkles in the sheet member even if the sheet member undergoes thermal expansion or contraction over time.

Brief Description of Drawings

FIG. 1 is a diagram schematically showing a configuration of a direct type surface light source to which a sheet member is attached using the method of the present invention.

FIG. 2 is a diagram schematically showing a configuration of a conventional direct type surface light source.

FIG. 3 is a view showing a frame of a surface light source that can be preferably used in the method of the present invention.

FIG. 4 is a diagram schematically showing an example of the sheet member attaching method of the present invention.

FIG. 5 is a diagram schematically showing the shape of an elastic body preferably used in the present invention.

FIG. 6 is a partially enlarged view of a surface light source frame with a sheet member using a linear elastic body.

FIG. 7 is a partially enlarged view of a surface light source frame with a sheet member using a plate-like elastic body 9b.

FIG. 8 is a partially enlarged view of a surface light source frame with a sheet member schematically showing a structure of a holding portion of a linear elastic body formed on the sheet member.

FIG. 9 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention.

FIG. 10 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention.

FIG. 11 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention.

FIG. 12 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention.

FIG. 13 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention. [14] FIG. 14 is a diagram schematically showing a state in which a sheet member is attached to a frame of a surface light source using the method of the present invention.

FIG. 15 is a diagram schematically showing a state in which the sheet member is supported on the side of the surface light source frame to which no elastic body is attached.

FIG. 16 is a view schematically showing a surface light source frame with a sheet member obtained in Example 1.

FIG. 17 is a diagram schematically showing a surface light source frame in Example 1.

FIG. 18 is a view schematically showing a sheet member in Example 1.

圆 19] FIG. 19 is a diagram schematically showing the shape of the holding part I in Example 1.

FIG. 20 is a diagram schematically showing the shape of a protrusion I in Example 1.

圆 21] A diagram schematically showing a surface light source frame with a sheet member obtained in Examples 2, 4, and 5.

FIG. 22 is a diagram schematically showing sheet members in Examples 2, 4, and 5.

FIG. 23 is a diagram schematically showing a surface light source frame in Examples 2, 4, and 5.

FIG. 24 is a diagram schematically showing a plate-like elastic body in Examples 2 and 3.

FIG. 25 is a view schematically showing a surface light source frame with a sheet member obtained in Example 3.

FIG. 26 is a diagram schematically showing a surface light source frame in Example 3.

FIG. 27 is a diagram schematically showing a surface light source frame in Example 6.

FIG. 28 is a view schematically showing a sheet member in Example 6.

FIG. 29] A diagram schematically showing the shape of a plate-like elastic body used in Example 6.

FIG. 30 is a diagram schematically showing a surface light source frame with a sheet member obtained in Example 6.

FIG. 31 is a view schematically showing the shape of a sheet member used in Example 3.

FIG. 32 is a diagram schematically showing the shape of a protrusion II in Example 3.

FIG. 33 is a diagram schematically showing a surface light source frame with a sheet member obtained by Examples 2, 4, and 5.

圆 34] A view schematically showing a surface light source frame with a sheet member obtained in Example 6. Ru

Explanation of symbols

1 Surface light source housing

Dual light source frame

3 Fluorescent tube

4 Reflective sheet

5 Milky white board

6 Diffusion sheet

7 Prism sheet

8 Polarized light separation sheet

9 Elastic body (9a: Linear elastic body, 9b: Plate elastic body)

10 Sheet material

11 Projections provided on the surface light source frame

12 Edge of frame of surface light source

13 Opening of area light source frame

14 Edge of casing of surface light source

15 Holding part for linear elastic body formed on surface light source frame

16 Holding part for linear elastic body formed on sheet member

17 Direction in which the linear elastic body pulls the sheet member (Tension applied to the sheet member)

18 Direction in which the linear elastic body pulls the surface light source frame

19 Direction in which the plate-like elastic body pulls the sheet member (Tension applied to the sheet member)

20 Direction in which the plate-like elastic body pulls the surface light source frame

21 Openings for protrusions formed on the sheet member

22 Opening for elastic plate-like body formed in the surface light source frame

23 Plate-like elastic body holding part formed on the surface light source frame

24 Openings for elastic plates formed in sheet members

25 Opening for plate-like elastic body formed in sheet member

BEST MODE FOR CARRYING OUT THE INVENTION [0020] The present invention has been developed by applying tension to the sheet member using an elastic body as a result of intensive studies on the above-described problem, that is, a method for attaching a sheet light source to a surface light source frame. As a result, it was clarified to solve all the powerful issues at once. That is, when the sheet member and the surface light source frame are pulled on each other by using an elastic body on at least one side of the sheet member, the sheet member is stretched on the surface light source frame while being held in tension. This has led to the completion of a sheet member mounting method that achieves the above problems.

[0021] In the sheet member mounting method of the present invention, at least one sheet member and the surface light source frame are stretched and attached to each other using at least one side of the surface light source frame using an elastic body. The sheet member is spread on the surface light source frame while being kept in a tension state. In other words, the sheet member is not always fixed to the surface light source frame with only an adhesive or a screw, but is always held in a state where tension is applied to the sheet member so as to follow the dimensional change of the sheet member. This is a mounting method that works. By adopting such a method, it is possible to absorb the change in the dimension of the sheet member over time and always stretch without stagnation.

[0022] As a specific aspect of the above-described method, for example, an opening A is provided in the sheet member, an opening a is provided in the surface light source frame, and an elastic body is inserted into the opening a through the opening A. Can be mentioned. At this time, the opening A is preferably dimensioned so that a gap is formed in a part between the opening A and the elastic body at the time of expansion.

Here, the surface light source frame is a member that forms a framework of the light source and surrounds the sheet member. For example, FIG. 1 shows a force that shows an example of the surface light source in the present invention. In the case of a surface light source, the case 1 or frame 2 is indicated.

[0024] Hereinafter, the sheet member mounting method of the present invention will be described with reference to Figs. In addition, a rectangular surface light source and a surface light source of a liquid crystal display device having only one light emitting surface will be described as an example. However, the shape of the surface light source is not limited to a square, and may be a polygon or a circle. It can be mounted in the same manner, and can be similarly applied to a lighting device such as two to four surfaces where the light emitting surfaces are not one surface. Among these, a substantially rectangular surface light source controls tension in either the vertical or horizontal direction or in two directions that intersect perpendicularly, making it easy to adjust the tension on the sheet member and spreading without wrinkles or itchiness. preferable. FIG. 3 shows a view of the surface light source frame used in the present invention when the light exit surface side force is seen. FIG. 3 (a) shows the upward force applied to the hollow housing in which the fluorescent tube 3 is accommodated. FIG. 3 (b) shows a hollow casing in which the fluorescent tube 3 is accommodated. In FIG. 3 (a), the edge 12 of the frame 2 is pulled with the sheet member, and the edge 14 of the housing is pulled with the sheet member in FIG. 3 (b). In the following description, the force for attaching the sheet member to the frame 2 provided separately from the case 1 is the same as the method for attaching the sheet member to the case 1 itself. For the sake of explanation, this is the method of mounting on the surface light source frame.

Next, FIG. 4 specifically shows how the sheet member 10 is extended to the frame 2. Figure 4 shows a schematic diagram of the surface light source frame 2 as seen from the light incident surface side (ie, back surface) force.

In the surface light source frame with sheet member shown in FIG. 4 (a), a linear elastic body is provided on the sheet member 10 and the frame 2 of the surface light source (surface light source frame) on at least one side of the frame 2. The holding portions (15, 16) are formed, and the linear elastic body 9a is held by the holding portions. As holding parts, there are a holding part 15 formed on the frame 2 and a holding part 16 formed on the sheet member 10, and linear elastic bodies are alternately held on them. Here, a linear elastic body 9a as shown in FIG. 5 (a) is used. Further, as will be described later, the sheet member 10 is held by being fitted to the frame 2 at a side opposite to the side where the linear elastic body 9a is held.

When the holding portions 15 and 16 are formed and the linear elastic body 9a is held by the holding portions 15 and 16, the linear elastic body 9a is bent as shown in FIG. 4 (a). Therefore, a force is applied to the frame 2 in the direction of the arrow 17 and a force is applied to the sheet member 10 in the direction of the arrow 18 by the bending restoring force of the linear elastic body 9a. The frame 2 is substantially a rigid body and does not deform even when a force is applied. As a result, the sheet member 10 is stretched by the force in the direction of the arrow 18.

On the other hand, a plate-like elastic body 9b is used in the surface light source frame with sheet member shown in FIG. 4 (b). In the case of this embodiment, as will be described later, both the sheet member 10 and the frame 2 are provided with openings (holes) for the plate-like elastic bodies 9b, and the plate-like elastic bodies are hooked on the openings, thereby the sheet member 10 Is drawn against frame 2. A force is applied to the frame 2 in the direction of the arrow 19, and a force is applied to the sheet member 10 in the direction of the arrow 20. Frame 2 is substantially rigid Since the sheet member 10 is not deformed even when tension is applied, the sheet member 10 is expanded by the force in the direction of the arrow 20 as a result.

[0030] Thus, in the embodiment shown in Fig. 4 (a), the linear elastic body 9a is alternately passed through and held by the holding portions formed on the frame and the sheet member, thereby expressing the bending restoring force. In the embodiment shown in FIG. 4 (b), the sheet member 10 is stretched, and the plate-like elastic body 9b is hooked on the opening formed in the frame 2 and the sheet member 10, thereby expressing an elastic force. The frame 2 and the sheet member 10 are pulled together, and the sheet member 10 is expanded.

[0031] In the present invention, as a method of generating tension by the elastic body 9, a method using a restoring force generated when bending is preferably used.

[0032] Examples of the material of the elastic body 9 include a wire, a metal wire, a grease rod, and the like. Among these, a piano wire is representative in terms of mechanical strength. Such metal wires are most preferred. Although there are no particular limitations on the plate-like material, such as metal and resin, stainless steel and aluminum are preferred as the metal, and polycarbonate resin and acrylonitrile 'butadiene' styrene (ABS) resin are preferred as the resin. Favored ,.

[0033] Examples of the shape include those shown in FIG. In other words, the line shape may be a long and narrow bar shape that does not need to be completely a straight line. In addition to a straight line shape (FIG. 5 (a)), a curved line shape (FIG. 5 (b)), a zigzag shape (FIGS. 5 (c) and (d)) and the like are also preferable. The plate shape is not particularly limited as long as it generates elasticity, but it is preferably a shape that generates elasticity by itself as shown in FIG. 5 (e), and more preferably in FIGS. 5 (f) and (g). In this way, a single elastic body has a plurality of elastic portions. (A) to (e) are all plan views of the elastic body, and (g) is a cross-sectional view of the elastic body taken along the line E-E shown in (f). The thickness of the plate-like elastic body 9b is not limited as long as it exhibits a bending restoring force, but is preferably 0.05 to LOmm, more preferably 0.5 to 5 mm.

Such an elastic body 9 is installed in either the casing 1 or the frame 2 in the surface light source, and stretches the sheet member 10.

[0035] The material of the sheet member 10 is not particularly limited, but polyester, polycarbonate, acrylic resin and the like are preferable. The thickness of the sheet member 10 is preferably 50 to: L000 μm, more preferably 100 to 500 μm. If it is 50 μm or less This is because wrinkles and creases that are poor in handling at the time occur, and if the length is 1000 m or more, it is difficult to carry out fine drilling.

[0036] When the surface light source frame is a surface light source frame for a liquid crystal display device, the sheet member is an optical sheet for a liquid crystal display device, and the optical sheet is light emitted from a fluorescent lamp. Is absorbed by a diffusion sheet that diffuses and isotropically diffuses, a reflection film that functions to reflect and reuse light, a prism sheet that collects diffused light, and a polarizing plate built into the liquid crystal cell. For example, a polarized light separating sheet that increases the efficiency of light utilization and improves the brightness by reflecting and reusing the polarized light component.

[0037] Next, the holding portion 15 formed in the frame 2 will be described. Fig. 6 is a partially enlarged view of a sheet light source frame with a sheet member using a linear elastic body 9a, where (a) is a plan view, and (b) to (f) are A-A arrows in (a). FIG. 6 is a cross-sectional view, and shows a variation of the shape of the holding part 15. (B) is a holding part that simply protrudes from the frame force, (c) and (e) are holding parts formed with barbs, and (d) and (f) are around the linear elastic body 9a. The holding part formed so as to be completely enclosed is shown. The holding unit 15 may be used by cutting out the force of the frame 2 itself, or may be added to the frame 2 by post-processing.

FIG. 8 is a partially enlarged view of the surface light source frame with a sheet member for explaining the holding portion 16 formed on the sheet member 10. (A) is a plan view, and (b) to (e) are cross-sectional views taken along the line CC of (a), showing the variation of the shape of the holding portion 16. (B) is a holding part that simply protrudes from the sheet member 10, (c) is a holding part in which a barb is formed, and (d) and (e) are so-called surroundings of the linear elastic body 9a. A loop-shaped holding part is shown. Similarly, the holding portion 16 may be formed by cutting out or processing the sheet member 10 itself, or may be added later.

[0039] Next, a method of fixing the frame 2 and the sheet member 10 in the surface light source frame with a sheet member using the plate-like elastic body 9b shown in Fig. 4 (b) will be described. FIG. 7 shows a partially enlarged view of a surface light source frame with a sheet member using the plate-like elastic body 9b. (A) is a plan view, and (b) to (e) are cross-sectional views taken along the line B-B of (a), showing a variation of the fixing method. (B) is a mode in which the opening 24 (opening A) is directly opened in the sheet member 10 and the plate-like elastic body 9b is passed through the opening 24 from the frame side. Opening 25 is formed and the opening 25 is a plate-like elastic body 9b, (d), (e) is a plate-like member that has an opening 24 (opening A) directly in the sheet member 10 and an opening 22 (opening a) in the frame 2. In this embodiment, the elastic body 9b is inserted into the opening 22 of the frame 2 through the opening 24 of the sheet member 10. The plate-like elastic body 9b may be welded to the frame body 12 as shown in FIGS. 7 (b) and 7 (c), and the opening 22 provided in the frame 2 as shown in FIGS. 7 (d) and (e). It may be inset. Further, as shown in FIG. 7 (e), the frame 2 may be provided with a holding portion 23 for holding the plate-like elastic body 9b.

[0040] As shown in FIG. 7 (d), the sheet member 10 is provided with an opening 24 and the frame 2 is also provided with an opening 22 while the plate-like elastic body 9b is passed through the opening 24 of the sheet member 10 When the sheet member is expanded by being fitted into the opening 22 of the frame 2, the sheet member is attached to the sheet member 10 by using only the elastic body without attaching a member such as a holder of the plate-like elastic body 9b to the sheet member 10 in advance. It can be extended to the frame body, and the elastic body can be attached from the side of the sheet member 10 instead of the side force of the frame 2, so that productivity can be improved and space for the production equipment can be saved. it can. At this time, the opening 24 of the sheet member 10 is dimensioned so that a gap is formed between the opening 24 and the elastic body at the time of expansion, so that the sheet member undergoes thermal expansion and contraction over time. However, it is possible to more reliably prevent the sheet member from being bent or wrinkled.

[0041] Next, the force for providing the elastic body 9 at which portion when the elastic member 9 is used to expand the sheet member 10 will be described. An example of the extension of the sheet member 10 using the linear elastic body 9a is shown in FIG. FIG. 4A shows an example in which the sheet member 10 is stretched by providing a linear elastic body 9 a only on one of the four sides of the frame 2. FIG. 9 is an example in which a linear elastic body 9a is provided on two adjacent sides for expansion, and FIG. 10 is an example in which a linear elastic body 9a is provided for extension on three sides. Further, FIG. 11 is an example in which the sheet member 10 is stretched while only the two corners of one side are held by the linear elastic body 9a. Similarly, an example of stretching the sheet member 10 using the plate-like elastic body 9b is shown in FIG. 4 (b) and FIGS. FIG. 4B shows an example in which the sheet member 10 is stretched by providing a plate-like elastic body 9 b on only one of the four sides of the frame 2. FIG. 12 is an example in which a plate-like elastic body 9b is provided and stretched on two adjacent sides, and FIG. 13 is an example in which a plate-like elastic body 9b is provided on three sides and extended. FIG. 14 shows an example in which only one corner of each side is held by the plate-like elastic body 9b and the sheet member 10 is extended.

[0042] When the sheet member 10 is stretched using the elastic body 9, one side of the frame 2 as shown in Figs. 4 (a) and 4 (b). It is more preferable to provide the elastic member 9 on at least two adjacent sides and hold the sheet member 10 as shown in FIGS. 9, 10, 12 and 13 than to provide the elastic member 9 alone and hold the sheet member 10. I like it. In order to spread the sheet member 10 more uniformly, it is necessary to apply tension in both the vertical and horizontal directions corresponding to the shape of the frame 2, that is, the quadrangle. For this purpose, at least one vertical and horizontal side of the frame 2 is an elastic body. The sheet member 10 is preferably held by 9. By holding the sheet member 10 with the elastic body 9 on at least two adjacent sides of the frame 2, tension is generated in both the vertical and horizontal directions, and the sheet member 10 can be stretched more uniformly.

[0043] Next, a sheet member holding method on the side opposite to the side on which the elastic body 9 is provided will be described. At this side, the sheet member 10 is held by being fitted to the frame 2, for example. Here, the state of the frame 2 and the sheet member 10 is shown in FIG. (A), (b) is a top view, (c), (d) is a side view. In the embodiment shown in these drawings, the sheet member 10 is not completely fixed to the frame 2, the opening 21 is formed in the sheet member 10, and the projection 11 is formed in the frame 2 so as to correspond to the opening 21. By passing the protrusion 11 of the frame 2 through the opening 21 of the sheet member 10, the sheet member 10 is fitted to the frame 2. Each of the opening 21 and the protrusion 11 may be provided with one size over one side of the sheet member 10 as shown in FIG. 15 (a), or in FIG. 15 (b). As described above, a plurality of sheets may be provided at substantially equal intervals with respect to one side of the sheet member 10. Further, the protrusion 11 may have a shape that protrudes vertically from the frame 2 as shown in FIG. 15 (c), or a shape in which a barb is formed as shown in FIG. 15 (d). There may be.

[0044] Note that the sheet member 10 can be held by providing the opening 21 and the protrusion 11 as described above on two opposite sides. However, in such a case, it is necessary to accurately match the formation position of the opening 21 with the formation position of the protrusion 11. That is, it is necessary to increase the dimensional accuracy when the opening 21 is formed in the sheet member 10. In addition, since it is necessary to perform the expansion while applying a strong tension to the sheet member 10 when attaching, workability may be deteriorated. Therefore, it is preferable that the opening 21 and the protrusion 11 as described above are provided on the side opposite to the side on which the stiffener 9 is provided to hold the sheet member 10. In this case, when the sheet member 10 is held and stretched by the opening 21 and the protrusion 11 on one side and by the elastic body 9 on the opposite side, the opening 21 provided on one side of the sheet member 10 is used. Since the sheet member 10 can be stretched by applying tension to the elastic body 9 after fitting the protrusion 11 to the protrusion 11, the sheet The workability is improved because it is not necessary to apply excessive tension to the member 10. Further, when the sheet member 10 is stretched by the elastic body 9, the sheet member 10 expands and contracts to some extent. Therefore, there is no problem even if the formation position of the opening 21 is slightly different from the formation position of the protrusion 11. That is, the dimensional accuracy in forming the opening 21 in the sheet member 10 may not be relatively high.

Furthermore, when the protrusion 11 is fitted into the opening 21, it is preferable that a gap is formed in a part between the opening 21 and the protrusion 11. That is, it is preferable that the opening 21 has such a dimension that a gap is formed in a part between the opening 21 and the protrusion 11 during expansion. When the sheet member 10 expands and contracts due to heat or the like, on the side of the side held by the elastic body 9, the elastic body 9 also expands and contracts following the expansion / contraction of the sheet member 10. On the other hand, on the side of the side fixed by the protrusion 11, the sheet member 11 cannot expand or contract unless there is a gap between the opening 21 and the protrusion 11. That is, since only the sheet member on the side held by the elastic body 9 expands and contracts, the sheet member 11 may be wrinkled. However, when the gap is provided as described above, the dimensional change of the sheet member 10 over time can be absorbed.

As described above, the sheet member is attached to the surface light source frame, and the surface light source frame with the sheet member is manufactured. If a surface light source frame with a sheet member is manufactured by a powerful method, a surface light source frame with a sheet member having various effects according to the above-described sheet member mounting method of the present invention can be obtained. It is preferable that the surface light source frame with a powerful sheet member is used as a surface light source for a force liquid crystal display device that can be used as a surface light source for various lighting fixtures and display devices. Of these, it is most effective to use a direct type surface light source in which the inside of the surface light source is hollow. These surface light sources can be combined with a liquid crystal cell to be used as a liquid crystal display device.

Example

[Example 1]

The holding part 1 (corresponding to the holding part 15) for holding the piano wire is formed on both of the long side and the short side of the frame I for the direct type surface light source (corresponding to the frame 2) as follows. did. In addition, protrusion I (corresponding to protrusion 11) was formed on both of the other long side and short side as follows. (See Figure 17).

[0048] (Frame I)

• Screen size: diagonal 32 inches (short side 420mm, long side 680mm) • Frame edge width: 25mm (short side), 20mm (long side)

(Holding part I)

• Position: Formed at the positions shown in FIG. 17 on the long side and the short side (dimensions indicate the length from the outer side of the frame to the center of the holding unit, the center of the holding unit to the center of the holding unit).

'Shape: The frame itself was cut out and processed into the shape shown in Fig. 19.

(Protrusion I)

• Position: Formed at the positions shown in Fig. 17 on the long and short sides (dimensions indicate the length from the outer edge of the frame to the center of protrusion and the center of protrusion to the center of protrusion) o

• Shape: The frame itself was cut out and processed into the shape shown in FIG.

[0049] Next, a diffusion sheet GM2 (manufactured by Kimoto Co., Ltd.) used as a surface light source for a liquid crystal display device as the sheet member 10 was formed into the shape shown in FIG. 18 (the dimensions are the outer edges of the sheet). The length of the opening center and the opening center to the opening center are shown.) O The holding portion 16 and the opening 21 are formed at the positions shown in FIG. As the holding portion 16, a loop-shaped structure as shown in FIG.

[0050] After that, when the diffusion sheet was held with respect to the frame I using two piano wires as shown in Fig. 16, it could be satisfactorily stretched without wrinkles and itchiness.

[0051] As for the piano wire, a piano wire having a diameter of lmm and a length of 700mm was used for the long side, and a piano wire having a diameter of lmm and a length of 440mm was used for the short side.

[0052] (Example 2)

As shown in Fig. 23, openings 22 (long side: 12mm, short side: 6mm, long side: each side of the frame) are inserted into four sides of the following frame II (corresponding to frame 2) for the direct type surface light source. (Dimensions indicate the length of the outer edge of the frame to the center of the opening, the center of the opening to the center of the opening). Furthermore, holding parts Π (corresponding to the holding part 23) for holding the plate-like elastic bodies on the four sides were formed as follows.

[0053] (Frame Π)

• Screen size: diagonal 32 inches (short side 420mm, long side 680mm)

• Frame edge width: 25mm (short side), 20mm (long side)

(Holding part Π)

• Position: Formed at a position corresponding to opening 22 (see Fig. 33 (b))

• Shape: The shape shown in Fig. 33 (b). Next, as shown in FIG. 22, openings 24 (long side 13 mm) are formed on the four sides of diffusion sheet GM2 (manufactured by Kimoto Co., Ltd.) used as a surface light source for liquid crystal display devices as sheet member 10. The short side is 5 mm and the long side is parallel to each side of the sheet) (the dimensions indicate the length from the outer side of the sheet to the center of the opening and from the center of the opening to the center of the opening).

[0055] After that, the stainless steel leaf spring shown in FIG. 24 was used to hold the diffusion sheet with respect to the frame II as shown in FIG. 21 and FIG. 33. I was able to. In FIG. 33, (a) is a plan view and (b) is a side view.

(Example 3)

As shown in Fig. 26, the opening 22 (long side 12mm, short side) that fits the plate-like elastic body on both the long side and short side of the following frame III (corresponding to frame 2) for direct type surface light 6mm, long side parallel to each side of the frame) (dimensions indicate the length of the outer side of the frame to the center of the opening and the center of the opening to the center of the opening). In addition, protrusion II (corresponding to protrusion 11) was formed on the other pair of long and short sides as follows.

[0056] (Frame III)

• Screen size: diagonal 32 inches (short side 420mm, long side 680mm)

• Frame edge width: 25mm (short side), 20mm (long side)

(Projection Π)

'Position: The short side and the long side were formed at the positions shown in FIG. 26 (the dimensions indicate the length from the inner side of the frame to the center of the protrusion and the center of the protrusion to the center of the protrusion).

• Shape: The frame itself was cut out and processed into the shape shown in Fig. 32.

Next, as shown in FIG. 31, openings 21 and 24 (each Each opening had a long side of 13 mm, a short side of 5 mm, and a long side parallel to each side of the sheet).

[0058] After that, as shown in FIG. 25, the diffusion sheet is pulled to the projection II formed on the frame III, and then, FIG.

When held using the plate-like elastic body made of stainless steel shown in Fig. 4, the diffusion sheet was able to spread well without wrinkles and stagnation.

[Example 4]

The same procedure as in Example 2 was performed except that polycarbonate resin was used as the material for the plate-like elastic body. As a result, it was possible to spread well without wrinkles and itchiness.

[0060] (Example 5)

When the same procedure as in Example 2 was performed except that ABS resin was used as the material for the plate-like elastic body, it was possible to stretch well without wrinkles and stagnation.

[Example 6]

As shown in FIG. 27, openings 22 for the plate-like elastic body were formed on all four sides of the frame 2 for the direct type surface light source. (A) is a plan view of the frame 2, and (b) shows details of the opening 22.

[0062] Next, as shown in FIG. 28, a diffusion sheet GM2 (manufactured by Kimoto Co., Ltd.) used as a surface light source for a liquid crystal display device as the sheet member 10 is used for a plate-like elastic body. Opening 24 was formed. Here, (a) is a plan view of the sheet member 10, and (b) shows details of the opening 24.

[0063] After that, when the sheet member 10 is held with respect to the frame 2 as shown in Fig. 34 and Fig. 30) by the polycarbonate leaf spring shown in Fig. 29, the sheet member 10 can be satisfactorily stretched without wrinkles and stagnation. I was able to. 29 (a) is a plan view of the leaf spring, (b) is a cross-sectional view taken along the line E-E of (a), and FIG. 34 uses the leaf spring shown in FIG. 29 (a). FIG. 5 is a plan view of a surface light source frame with a sheet member, and (b) is a cross-sectional view taken along line FF in (c).

Industrial applicability

[0064] By applying the sheet member mounting method of the present invention to various illumination devices, display devices, particularly direct type surface light sources of liquid crystal display devices, it is possible to develop a thin and high screen uniformity.

Claims

The scope of the claims

[I] By pulling at least one sheet member and the surface light source frame with an elastic body on at least one side of the surface light source frame, the surface light source is kept in a tensioned state. A method for attaching a sheet member to be extended to a frame.

[2] The sheet member is provided with an opening A, the surface light source frame body is provided with an opening a, and the elastic member is passed through the opening A to be fitted into the opening a to expand the sheet member. The sheet member attaching method according to 1.

[3] The sheet member mounting method according to claim 2, wherein the opening A has a size such that a gap is formed in a part between the opening A and the elastic body during expansion.

[4] The sheet member mounting method according to any one of claims 1 to 3, wherein the sheet member is held by being fitted to the surface light source frame at the opposite side of the side to be pulled using the elastic body.

[5] An opening is formed in the sheet member at the opposite side of the side to be pulled using the elastic body.

5. The sheet member mounting method according to claim 4, wherein B is provided, and a protrusion is provided on the surface light source frame, and the sheet member is fitted to the surface light source frame by passing the protrusion through the opening B.

6. The sheet member mounting method according to claim 5, wherein the opening B has a dimension such that a gap is formed in a part between the opening B and the protrusion during expansion.

7. The seat member mounting method according to claim 1, wherein the elastic body is a linear elastic body or a plate-like elastic body.

[8] The sheet member mounting according to any one of claims 1 to 7, wherein the sheet member and the surface light source frame are provided with elastic bodies on at least one pair of adjacent sides of the surface light source frame. Method.

9. The sheet member mounting method according to claim 1, wherein the surface light source frame is a surface light source frame for a liquid crystal display device, and the sheet member is an optical sheet for a liquid crystal display device. .

[10] A method for producing a surface light source frame with a sheet member, wherein the sheet member is attached to the surface light source frame by the method according to any one of claims 1 to 9.

[II] A surface light source using a surface light source frame with a sheet member obtained by the method according to claim 10. 12. A liquid crystal display device using the surface light source according to claim 11.