JPH09211229A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily assemble a display device which has many optical fibers arranged between a display body, formed of a liquid crystal display panel, and a screen so as to enlarge an image. SOLUTION: A light guide block 5 which is arranged between the display body and screen is formed by using many optical fibers having their cores 12 coated with clads, and many cores 12 which are made wider or larger in diameter at their projection surface side end part than their incidence surface side end parts are put together and mutually joined together by a joining member 13a composed of a clad. Therefore, the light guide block 5 is only built in at the time of the assembly and the assembling operation can easily be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device such as a liquid crystal display device.

[0002]

2. Description of the Related Art In a display device, in order to enlarge an image, a large number of optical fibers are arranged between a display body such as a liquid crystal display panel and a screen, and the end portions of the optical fibers on the screen side are arranged. There is one in which the arrangement interval is made larger than the arrangement interval of the end portions of the optical fibers on the display body side (for example, refer to Japanese Patent Laid-Open No. 2-2944684). In this case, the screen has a structure in which a large number of through holes are formed in the screen plate and a diffusion layer is provided on the surface of the screen plate. Then, the output surface side end portions of many optical fibers are inserted from the back surface side into the through holes of the screen plate.

[0003]

However, in such a conventional display device, it is necessary to insert one end of each of a large number of optical fibers on the side of each emission surface into the corresponding through hole of the screen plate. However, there is a problem that the assembling work takes a lot of time and becomes expensive. Further, since the work of inserting the end portion of the optical fiber on the emission surface side into the through hole of the screen plate is manually performed, the length of the optical fiber has to be lengthened to some extent, which in turn enlarges the entire apparatus. There is a problem.
An object of the present invention is to easily perform an assembly operation,
In addition, the entire device can be downsized.

[0004]

According to the present invention, a large number of light guide paths, each having an exit surface side end portion wider or larger in diameter than an entrance surface side end portion, are closely packed and joined together by a joining material. The light guide block is arranged on the image display surface side of the display body.

According to the present invention, a large number of light guide paths whose end portions on the output surface side are wider or larger in diameter than the end portions on the incident surface side are densely packed and bonded to each other by a bonding material. Since the light guide block is formed, the light guide block can be assembled at the time of assembly, and therefore, the assembling work can be easily performed, and since the light guide block can be assembled, the length of the light guide path can be reduced. The overall size of the device can be reduced.

[0006]

1 is a perspective view of a main part of a display device according to an embodiment of the present invention. This display device includes a liquid crystal display panel (display body) 1.
A light guide 2 is arranged on the back surface side of the liquid crystal display panel 1, and a fluorescent tube 3 and a reflector 4 are arranged on the predetermined one end side of the light guide 2. Although not shown in detail, the light guide 2 has a structure in which a reflection layer is provided on the back surface of the light guide plate and a predetermined refraction plate is provided on the surface of the light guide plate. And
The light emitted from the fluorescent tube 3 and the light reflected by the reflector 4 are made incident on a predetermined one end surface of the light guide plate and converted into a surface light source by the surface light source conversion optical system including the light guide plate and the reflection layer.
The light, which has been converted into a surface light source, is made into parallel light which is perpendicular to the back surface of the liquid crystal display panel 1 by the refraction plate, and the back light of the liquid crystal display panel 1 is irradiated with this parallel light.
A light guide block 5 and a screen (diffusion plate) 6 are arranged on the front surface side (image display surface side) of the liquid crystal display panel 1.

The light guide block 5 is as shown in FIG. Next, the structure of the light guide block 5 will be described together with its manufacturing method with reference to FIGS. 3 and 4 in order. First, as shown in FIG. 3, a large number of optical fibers 11 having a predetermined length, a lower mold 21, and an upper mold (not shown) are prepared. The optical fiber 11 includes a core 12 made of an acrylic resin having a high refractive index and a clad 1 made of a fluororesin (a thermoplastic resin having a thermal expansion property) having a low refractive index.
It is coated with 3. The inside of the lower mold 21 has a rectangular parallelepiped shape.

Then, as shown in FIG. 3, a large number of optical fibers 11 are housed in a lower mold 21 while being closely packed in the vertical and horizontal directions. Next, when the inside of the lower mold 21 is sealed with the upper mold and then heated, the clad 13 melts and expands, filling the gaps between each of the plurality of cores 12, and thus the lower mold 2
1 and the upper mold are filled with a large number of cores 12 which are bonded to each other by a bonding material composed of a clad 13. Before the inside of the lower mold 21 is sealed with the upper mold, the same material (fluorine-based resin) as that of the clad 13 may be filled in the gaps between the plurality of optical fibers 11. This filling may be a different material than the clad 13. As a result, as shown in FIG. 4, a rectangular parallelepiped light guide block forming body 14 in which a large number of cores 12 are densely packed and joined to each other by the joining material 13 a made of the clad 13 is obtained.

Next, although not shown, the end of the light guide block forming body 14 on the side of the exit surface is clamped and fixed by a fixture, and the end of the light guide block forming body 14 on the side of the incident surface is formed. Hold it with a stretching tool and heat it while pulling to a high temperature. Then, the light guide block forming body 14 between the fixing tool and the stretching tool is stretched so as to become gradually thinner from the exit surface side toward the entrance surface side. Next, a predetermined portion in the vicinity of the portion of the light guide block forming body 14 held by the drawing tool is cut. Then, the light guide block 5 having the structure shown in FIG. 2 is obtained. In the light guide block 5 obtained in this manner, a large number of cores (light guide paths) 12 whose exit surface side ends are wider or larger in diameter than the entrance surface side ends are densely packed,
In addition, the entire structure is covered with the bonding material 13a made of the clad 13 and bonded to each other.

As described above, in this display device, the joining material 1 made of the clad 13 is formed by densely packing a large number of cores 12 whose ends on the emission surface side are wider or larger in diameter than the ends on the incident surface side.
The light guide block 5 is formed by joining the parts 3a to each other.
Since the light guide block 5 is formed, the light guide block 5 may be incorporated at the time of assembling, so that the assembling work can be easily performed. Further, since it is sufficient to incorporate the light guide block 5, the length of the optical fiber 11 can be shortened as much as possible, and the entire device can be miniaturized.

In the above embodiment, as shown in FIG. 1, one light guide block 5 is provided on the front surface side of the liquid crystal display panel 1.
However, the present invention is not limited to this. For example, as shown in FIG. 5, the first light guide block 5 is arranged on the front surface side of the liquid crystal display panel 1, and the second light guide block 15 is arranged on the emission surface side of the first light guide block 5. May be. In this case, the second light guide block 15 has the same basic structure as the first light guide block 5, but is slightly larger than the core 12 of the first light guide block 5 in order to enlarge the image more greatly. The structure is one size larger than the first light guide block 5 by using the core.

Although the plastic optical fiber is used in the above embodiment, a glass optical fiber in which a core made of glass having a high refractive index is covered with a clad made of glass having a low refractive index may be used. Further, instead of the step type optical fiber as described above, a graded type optical fiber may be used. Furthermore, although a liquid crystal display panel (LCD) is used as a display body in the above embodiment, an EL display, an LED display, a CRT display, a plasma display or the like may be used.

[0013]

As described above, according to the present invention, a large number of light guide paths, each having an exit surface side end portion which is wider or larger in diameter than an entrance surface side end portion, are densely packed together and bonded to each other. Since the light guide block is formed by joining, it is sufficient to incorporate this light guide block at the time of assembly.
Therefore, the assembling work can be easily performed, and since the light guide block may be incorporated, the length of the light guide path can be shortened as much as possible, and the entire device can be downsized.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a display device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a light guide block.

FIG. 3 is a partial perspective view showing a state in which a large number of optical fibers are housed in a lower mold when manufacturing a light guide block.

4 is a perspective view showing a rectangular parallelepiped light guide block forming body obtained by the manufacturing process shown in FIG.

FIG. 5 is a perspective view of a main part of a display device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel (display body) 5 Light guide block 11 Optical fiber 12 Core (light guide path) 13 Clad 13a Bonding material

Claims (6)

[Claims] 1. A light guide block of a display body, wherein a plurality of light guide paths, each of which has an exit surface side end portion wider or larger in diameter than an entrance surface side end portion, are densely packed and bonded to each other by a bonding material. A display device arranged on the image display surface side. 2. A display member having an image display surface, and a large number of light guide paths arranged on the image display surface side of the display member and having an emission surface side end portion wider or larger in diameter than the incidence surface side end portion. And a first light guide block, which is densely bonded to each other and is bonded to each other by a bonding material, and is disposed on the emission surface side of the first light guide block, and the emission surface side end is wider or larger than the incidence surface side end. A display device comprising: a second light guide block in which a large number of large light guide paths are closely packed and bonded to each other by a bonding material. 3. The method according to claim 1, wherein
The display device, wherein the bonding material is made of a thermoplastic resin having a thermal expansion property. 4. The invention according to claim 1 or 2,
The display device, wherein the bonding material is made of a material having a refractive index smaller than that of the light guide path. 5. The invention according to claim 1 or 2,
The display device is characterized in that the light guide path is made of an acrylic resin, and the bonding material is made of a fluorine resin. 6. The invention according to claim 1 or 2,
The display device is characterized in that the light guide path is made of glass having a high refractive index, and the bonding material is made of glass having a low refractive index.