JPH0950704A - Method of joining light source and light guide plate - Google Patents

Abstract

(57) [Abstract] [Purpose] When joining a light source and a light guide plate, a method of joining the light source and the light guide plate that can obtain sufficient light introduction efficiency even if there is some unevenness on each joining surface. I will provide a. [Structure] A light source composed of a support body 3 on which an LED lamp 2 is mounted and an end surface 5 of a light guide plate 1 are joined via a transparent elastic body 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining an LED light source and a light guide plate, and more particularly to a method for joining a light source used for a backlight and a light guide plate.

[0002]

2. Description of the Related Art LED lamps have attracted attention as a surface light source for backlights of thin display devices that do not emit light such as liquid crystal displays. A light source using an LED lamp is a surface light source in which light from the LED lamp is introduced from an end surface corresponding to the thickness direction of the light guide plate and totally reflected in the surface direction. The thickness of the light guide plate is usually as thin as about 2 to 5 mm, and light is introduced into the light guide plate by embedding the LED lamp in the end face of the thin light guide plate or by closely attaching it via a support or the like.

FIG. 4 is a sectional view showing a state of a surface light source in which an LED lamp light source is joined to an end surface of a light guide plate 11 by a conventional method. Support 1 with LED lamp 12 mounted
By joining 3 and the end surface of the light guide plate 11, the flat surface of the light guide plate 11 serves as a surface light source. In addition, the support 13 may be provided with a recess for inserting the end surface of the light guide plate 11. The support 13 is used when fixing the LED lamp 12 and bringing the LED lamp 12 into close contact with the end surface of the light guide plate 11 to introduce light, and is joined to the end surface of the light guide plate 11. Conventionally, in order to join the light source and the end surface of the light guide plate 11, a method of butting and a method of filling and bonding with an adhesive have been generally used. FIG. 4 shows a state in which the light source and the light guide plate 11 are joined together by a method of butting. The end face of the light guide plate 11 is inserted into the recess provided in the support body 13 on which the LED lamp 12 is mounted. The light source and the light guide plate 11 are joined together. The method of filling and bonding with an adhesive is to insert the end face of the light guide plate 11 into the recess provided in the support 13 on which the LED lamp 12 is mounted, as in the method of butting shown in FIG. However, the concave portion of the support 13 and the end surface of the light guide plate 11 are joined together with a transparent adhesive.

[0004]

To join the LED light source and the end face of the light guide plate, there are the method of butting and the method of interposing an adhesive as described above. However, in the method of butting, which is closely fixed without using an adhesive or the like, when the bonding surface between the light source and the light guide plate is not a smooth mirror surface, a gap is created in the bonding surface and an air layer is formed between the light source and the end surface of the light guide plate. However, there is a problem in that the efficiency of introducing light becomes poor. Further, in the method of joining the light source and the light guide plate through the adhesive, the light introduction efficiency is good because, for example, an epoxy resin or the like is used as the adhesive. However, such an adhesive has a low workability due to its low viscosity, and it has to be held under the curing conditions until it is cured, and there is a problem that an adhesive error such as an outflow of the adhesive is likely to occur. Further, the adhesive is difficult to adhere unless it has a smooth mirror surface, and bubbles may be mixed in at the time of curing.

Therefore, the present invention has been made in view of such circumstances, and an object thereof is to join the light source and the light guide plate even if there are some irregularities on the respective joining surfaces. An object of the present invention is to provide a method of joining a light source and a light guide plate, which can obtain sufficient light introduction efficiency.

[0006]

A method of joining a light source and a light guide plate according to the present invention is a method of joining a light source in which an LED lamp 2 is mounted on a support 3 and an end face 5 of the light guide plate 1. Then, the support 3 and the end surface 5 of the light guide plate 1 are joined to each other through the transparent elastic body 4.

FIGS. 1 (a) and 2 (a) are views showing a method of the present invention, in which a light source in which an LED lamp 2 is mounted on a support 3 and an end surface 5 of a light guide plate 1 are joined together. Thus, the flat surface of the light guide plate 1 serves as a surface light source. The support 3 and the end surface 5 of the light guide plate 1 are joined via a transparent elastic body 4.

The method of joining the light source and the light guide plate of the present invention is a method of joining the recess 6 of the light source in which the LED lamp 2 is mounted on the support 3'and the end surface 5 of the light guide plate 1. The concave portion 6 provided in the light source and the end surface 5 of the light guide plate 1 are fitted and inserted through the transparent elastic body 4.

As shown in FIGS. 1 (b) and 2 (b),
A recess 6 is formed on the support 3 ′ of the light source so as to fit with the end surface 5 of the light guide plate 1. The end surface 5 and the recess 6 are joined via a transparent elastic body 4. As described above, it is possible to join the support as it is without providing the recess, but since the displacement of the bonding position occurs, the method of forming the recess in the support and inserting the end face of the light guide plate to join Is preferred.

The elastic body 4 is not particularly limited as long as it has elasticity, but is not limited to LE.
A resin or rubber that transmits the light emitted from the D lamp 2 is used, and preferably, one of silicone resin, silicone rubber, acrylic foam, and an adhesive having elasticity is used. As the adhesive having elasticity, for example, a double-sided tape in which an adhesive is applied to both surfaces of an elastic substrate, a transparent adhesive having elasticity even after adhesion, or the like is used. Further, as the light guide plate 1, for example, acrylic, polycarbonate or the like can be used.

[0011]

In the joining method of the present invention, as shown in FIGS. 1 and 2, the end face 5 of the light guide plate 1 and the support 3 or 3'on which the LED lamp 2 is mounted are attached to the transparent elastic body 4. Join through. Therefore, an adhesive error such as an outflow of the adhesive, which has been a problem when the adhesive is bonded via the adhesive, does not occur, and there is no possibility that air bubbles are mixed.

Furthermore, in the conventional method of butt and filling adhesion, when the joint surface of the light source or the light guide plate is not a smooth mirror surface but has irregularities, a gap is created in the joint surface and an air layer is formed between the light source and the light guide plate. However, in the present invention, such a problem is eliminated because the bonding is performed via the elastic body 4. This is because the elastic body 4 acts as a cushion to fill the gap formed between the light source and the light guide plate 1.

Further, FIG. 3 is a sectional view showing a state in which the light source and the light guide plate are joined by the method of the present invention as in FIG. The LED lamp 2 is mounted on the support 3'to serve as a light source. At this time, the bonding surface A of the support 3'and the LED lamp 2
If the LED lamp 2 is not mounted such that the ends of the LED lamp 2 are flush with each other, a step will be formed between the joint surface A of the support 3'and the tip of the LED lamp 2. That is, the tip of the LED lamp 2 projects from the joint surface A of the support body 3'as shown in FIG. 3A, or the joint surface A of the support body 3 as shown in FIG. 3B.
Even if a work error such as a depression occurs, the elastic body 4 is provided between the joint surface A of the support body 3 ′ and the tip of the LED lamp 2 by using the joining method of the present invention, as described above. Since the created step is filled, the light introduction efficiency does not decrease.

By the way, when silicone resin, silicone rubber, acrylic foam or the like is used as the elastic body, there is an advantage over the conventional method in that the workability is good and the light introduction efficiency is not reduced as described above. In order to bond the light source and the light guide plate using the elastic body, it is necessary to apply a certain amount of pressure at the time of bonding and continue to hold them. However, when the light source and the light guide plate are joined using an elastic adhesive, it has adhesiveness unlike silicon resin or acrylic foam, so it is possible to maintain that state by simply applying pressure instantaneously. The sexuality becomes even better.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples show one example of the present invention, and do not limit the present invention to the following.

FIG. 1 is a perspective view for explaining the method of the present invention, and FIG. 2 is a cross-sectional view showing a joined state of a light source and a light guide plate according to one embodiment of the method of the present invention. Is a light guide plate, 2 is an LED lamp, 3 and 3'are supports, 4 is a transparent elastic body, 5 is an end face of the light guide plate 1, and 6 is a recess formed in the light source support 3 '. .

[Embodiment 1] The size is 126 × 96 × 3t.
A light guide plate 1 is screen-printed with a diffusion pattern on the back surface of the acrylic plate. Subsequently, the emission wavelength is 480n
m, high-intensity blue LED lamp 2 having a light emission output of 2 mW
Are prepared and fixed to the support 3 made of white polycarbonate at equal intervals to produce a bar light source.

Next, the end face 5 of the above light guide plate 1 is shown in FIG.
As shown in (a), the transparent elastic body 4 is bonded to the light source through the silicone resin. FIG. 2A shows the light guide plate 1 at this time.
It is sectional drawing which shows the joined state of a light source.

[Embodiment 2] A light guide plate 1 and a light source are manufactured in the same manner as in Embodiment 1. Next, the light source and the light guide plate 1 are attached to a transparent double-sided tape (thickness: 0.125 mmt, manufactured by 3M F-946).
9pc) to join. This double-sided tape is used in place of the elastic body 4 such as the silicone resin used in Example 1, and is made of a transparent adhesive having elasticity even after the bonding.

[Embodiment 3] A light guide plate 1 is manufactured in the same manner as in Embodiment 1. Then, the high-intensity blue LED lamp 2
A bar light source is manufactured by fixing the support 3'of white polycarbonate at equal intervals. At this time, a recess 6 that fits into the end surface 5 of the light guide plate 1 is formed in the support 3'of white polycarbonate as shown in FIG.

Next, the end face 5 of the light guide plate 1 is attached to a transparent double-sided tape (made by 3M # 948) having a thickness of 0.120 mmt.
Insert into the recess 6 of the light source via 3). This double-sided tape is also used in place of the elastic body 4 such as a silicone resin as in the second embodiment, and is made of a transparent adhesive that has elasticity even after being bonded. FIG. 2B is a cross-sectional view showing the joined state of the light guide plate 1 and the light source at this time.

[Fourth Embodiment] A light guide plate and a light source are manufactured in the same manner as in the third embodiment. Subsequently, the concave portion 6 of the light source is inserted through a transparent double-sided tape (Y-4910J manufactured by 3M) having a thickness of 1 mmt, in which an adhesive is applied to both sides of an acrylic foam which is an elastic body.
And the end surface 5 of the light guide plate are joined.

The emission luminance and the introduction of light measured respectively for the surface light source in which the light source and the light guide plate are bonded by the method of Examples 1 to 4 of the present invention and the surface light source in which the light source and the light guide plate are bonded by the butt method as a conventional example, respectively. The efficiency is shown in Table 1. However, in Examples 1 to 4 and the conventional example, the material and size of the light guide plate used, the light emission output and the number of LED lamps, etc.
All measurement conditions are the same, and only the joining method is different. As can be seen from this table, the surface light source obtained by the conventional method showed an emission luminance of 116.9 nits, whereas the surface light source obtained by the method of the present invention showed a maximum emission luminance of 146.7 nits. . Regarding the light introduction efficiency, when the surface light source obtained by the conventional method was set to 100%, the surface light source obtained by the method of the present invention was improved up to 125.5%.

By joining the light guide plate 1 and the light source using the method of the present invention as described above, it is possible to improve the emission brightness and the light introduction efficiency as compared with the conventional joining by butting.

[0025]

[Table 1]

In this embodiment, a high-intensity blue LED lamp is used as the LED lamp 2, but it is not particularly limited. White polycarbonate was used as the support for the light source, but other acrylic, liquid crystal polymer, PBC, A
Any material with good reflection efficiency such as BS may be used. Further, although screen printing is used as the light diffusion method, any other method such as blasting or molding that can obtain uniform surface emission may be used.

[0027]

As described above, according to the method of the present invention, since the light source and the light guide plate are joined through the transparent elastic body, the light source and the light guide plate can be formed even if there are some irregularities on their joining surfaces. Since there is no air layer between them, it is possible to further improve the light introduction efficiency as compared with the conventional butt-matching method. Further, in the conventional method of joining via an adhesive, an adhesion error such as outflow is likely to occur, but the method of the present invention has an advantage that the adhesion error hardly occurs and the workability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a light source is joined to a light guide plate by the method of the present invention.

FIG. 3 is a cross-sectional view showing a state in which a light source is joined to a light guide plate by the method of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a light source is joined to a light guide plate by a conventional method.

[Explanation of symbols]

 1, 11 ... Light guide plate 2, 12 ... LED lamp 3, 3'13 ... Support 4 ... Transparent elastic body 5 ... End face of light guide plate 6 ...・ Recess

Claims (3)

[Claims] 1. A method for joining a light source in which an LED lamp 2 is mounted on a support 3 and an end surface 5 of a light guide plate 1, wherein the support 3 and the end surface 5 of the light guide plate 1 are transparent. A method of joining a light source and a light guide plate, characterized by joining via an elastic body 4. 2. A method of joining a concave portion 6 of a light source in which an LED lamp 2 is mounted on a support body 3 ′ and an end surface 5 of a light guide plate 1, the concave portion 6 being provided on the support body 3 ′. A method of joining a light source and a light guide plate, wherein the light guide plate 1 and the end surface 5 of the light guide plate 1 are fitted and inserted through a transparent elastic body 4. 3. The light source and the light guide plate according to claim 1, wherein the elastic body 4 is made of silicone resin, silicone rubber, acrylic foam, or an adhesive having elasticity. How to join with.