JP2872143B2 - Light guide plate device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate device, and more particularly to a light guide plate device suitable for a backlight in a liquid crystal display device.

[0002]

2. Description of the Related Art It is well known that a liquid crystal display device is frequently used in various electronic devices. In particular, liquid crystal display devices are frequently used in portable electronic devices, which have become remarkably popular in recent years. In general, such liquid crystal display devices are provided with a backlight in order to enhance visibility.

[0003] The light guide plate device constituting the above-mentioned backlight includes:
It is described in Japanese Utility Model Laid-Open No. 4-107201. FIG.
Is a diagram described in the above publication, in which a light guide plate device 1 is provided with light sources 3 and 3 and a light guide plate 4 in a casing 2. In this case, the surface of the light guide plate 4
A light emitting surface 4a to which a diffusive sheet is attached is provided.
Is a reflection surface 4b on which a reflective sheet is stuck and a pattern for forming irregular reflection is formed.

In the light guide plate device 1, the light sources 3, 3
From the light guide plate 4 is reflected toward the front surface side by the reflection surface 4b. The light reflected on the front side is the light emitting surface 4
Light is emitted from a as diffused light. The emitted light is provided to a backlight or the like of a liquid crystal display device (not shown).

[0005]

However, in the above-mentioned conventional light guide plate device 1, since light leaks from the side surfaces 5, 5 of the light guide plate 4, there is a problem that the luminance on the light emitting surface 4a is small.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light guide plate device capable of improving luminance in a light emitting area.

[0007]

In the light guide plate device according to the present invention, the light source, the light source is disposed along at least one side edge, the front surface is a light emitting surface, and the back surface is a reflective surface. is a plan view rectangular plate member, Ri light guide plate apparatus der comprising a light guide plate to emit light from the light emitting surface by reflecting light received from the light source by the reflection surface, the light guide
In the plate, the light guide plate is attached to the casing of the light guide plate device.
The illuminated body is attached to the mounting leg for
A holding portion for holding the light guide plate;
, The said light sources along the side edges that are not disposed, at a position separated from the side edge inwardly, a light guide plate apparatus slits are formed, located on the inner side of the slit
It is characterized in that a mirror surface is applied to the wall surface to be processed . In the light guide plate apparatus according to claim 2, wherein the light guide plate apparatus according to claim 1, the wall surface located on the inner side of the slit, instead of the mirror-finished, colored
It is characterized by being given . In the light guide plate device according to claim 3, in the light guide plate device according to claim 1 , instead of the mirror finishing, affixing or applying a reflective material is applied to the wall surface located inside the slit. Out
It is characterized by being.

According to the first aspect of the invention, the light incident on the light guide plate from the light source travels through the light guide plate while being emitted from the light emitting surface while being reflected on the reflection surface. This light travels toward the side edge of the light guide plate and reaches the slit. Since the refractive index of the slit is different from that of the light guide plate, the light reaching the slit is reflected toward the inside of the light guide plate. Therefore, dissipation of the light that has entered the light guide plate from the light source is prevented, and the luminance of the light emitting region is improved. At that time, inside the slit
The mirror surface has been applied to the wall located on the side
As a result, the light that reaches the slit is directed inward of the light guide plate.
Is reflected. In addition, the light guide plate includes a casing of the light guide plate device.
The light guide plate is
No additional members are required when attaching to
No. Also, it is easy to mount, and the light guide plate
It is composed of impact. Furthermore, the light guide plate has a light emitting surface side
A holding part for holding the illuminated body is formed in
In order to hold the illuminated object,
Absent. Also, it is easy to install, and the light guide plate device is
It is compact. According to the second aspect of the invention, since the wall surface located on the inner side of the slit is colored, the light reaching the slit is reflected toward the inner side of the light guide plate. According to the third aspect of the present invention, since the reflective material is applied or applied to the wall surface located on the inner side of the slit, the light reaching the slit is directed to the inner side of the light guide plate. Is reflected.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of the light guide plate device of the present invention. The light guide plate device 10 in the present embodiment is used, for example, as a backlight in a liquid crystal display device.

Referring to FIG. 1, a light guide plate device 10 includes a casing 11, a light source 12, a light guide plate 13, and the like.

The casing 11 houses the light source 12 and the light guide plate 13, and a liquid crystal display device (not shown) is mounted on the casing 11.

The light source 12 is connected to a power supply device (not shown) and is arranged along one side edge 13 a of the light guide plate 13.

The light guide plate 13 is formed of a transparent plastic such as acrylic resin, and is a rectangular plate in a plan view having a light emitting surface 14 on the front surface and a reflective surface 15 on the back surface. . Here, a diffusive sheet (not shown) can be attached to the light emitting surface 14, and a reflective sheet can be attached to the reflective surface 15 and a pattern for forming irregular reflection is formed. Can be.

The greatest feature of the present embodiment is that the slit 16 is formed in the light guide plate 13. The slit 16 has a thickness of the light guide plate 13 along a side edge 13b, 13c, 13d of the light guide plate 13 where the light source 12 is not arranged, and at a position inwardly separated from the side edges 13b, 13c, 13d. It is formed throughout. In this case, of the light emitting surface 14, the slit 16
The region located inward forms the light emitting region.

In this embodiment, the wall surface 16a located on the inner side of the slit 16 is mirror-finished.

Next, the operation of the light guide plate device 10 configured as described above will be described. Light source 12 to light guide plate 13
As shown in FIG. 3, the light incident inside the light guide plate 13 is emitted from the light emitting surface 14 while being reflected by the reflective surface 15.
Go inside. This light is applied to the side edges 13b, 13b of the light guide plate 13.
It proceeds toward c and 13d and reaches the slit 16. The light that has reached the slit 16 is reflected by the wall surface 16 a of the slit 16.
Is mirror-finished, the light is reflected toward the inside of the light guide plate 13 on the wall surface 16a. Therefore, dissipation of light that has entered the light guide plate 13 from the light source 12 is prevented. The light reflected inward of the light guide plate 13 is
Similarly, the light travels through the light guide plate 13 while being emitted from the light emitting surface 14 while being reflected by the reflection surface 15.

In the light guide plate device 10, the side edges 13
Since slits 16 are provided in the vicinity of b, 13c and 13d, the light enters the light guide plate 13 from the light source 12 and
The light traveling through the inside and reaching the slit 16 is transmitted to the light guide plate 13.
Can be effectively reflected inward. Therefore, it is possible to prevent the light that has entered the light guide plate 13 from the light source 12 from dissipating, and to improve the luminance in the light emitting region. Therefore, sufficient luminance can be ensured even with a small light source 12, and the size of the light guide plate device 10 can be reduced. In addition, the number of light sources 10 can be reduced, and effects such as reduction in power consumption can be obtained.

[Second Embodiment] FIG. 4 shows a light guide plate according to a second embodiment of the present invention. This embodiment is different from the first embodiment only in that the wall surface 16a located on the inner side of the slit 16 is colored instead of being mirror-finished. The other configuration is the same as that of the first embodiment, and a description thereof will be omitted.

In the light guide plate device 20 of the present embodiment,
The wall surface 16 a of the slit 16 is colored and provided with a colored coating film 21.

In the present embodiment, similarly to the first embodiment, the light that has reached the slit 16 is
1, the light can be effectively reflected toward the inside of the light guide plate 13. Therefore, it is possible to prevent the light that has entered the light guide plate 13 from the light source 12 from dissipating, and to improve the luminance in the light emitting region.

As a modification of this embodiment, instead of coloring, there is a method of attaching a reflective material (for example, a silver film), or applying a reflective paint (a paint containing metal powder). Similar effects can be obtained in these alternative methods.

Third Embodiment FIG. 5 shows a third embodiment of the light guide plate of the present invention. The present embodiment is different from the first embodiment in that the light guide plate 13 includes
The only difference is that the holding portion 32 is formed integrally with the light guide plate 13. The other configuration is the same as that of the first embodiment, and a description thereof will be omitted.

The mounting leg 31 connects the light guide plate 13 to the light guide plate device 3.
0 for attaching to the casing 11. The holding section 32 is for holding a liquid crystal display (illuminated body) 33 on the light emitting surface 14 side.

In this embodiment, the light guide plate 13 includes
Since the attachment leg 31 for the casing 11 of the light guide plate device 30 is formed, no additional member is required when attaching the light guide plate 13 to the casing 11.
And attachment can be performed easily. Therefore, the number of parts can be reduced, and the manufacturing can be easily performed.
Manufacturing costs can be reduced. Moreover, the light guide plate device 30 can be made compact.

Further, since the light guide plate 13 is provided with the holding portion 32 for holding the liquid crystal display 33 on the light emitting surface 14 side, a separate member is required for holding the liquid crystal display 33. And can be easily mounted. Moreover, the light guide plate device 30 can be made compact.

Note that the present invention is not limited to the above-described embodiment, but may be configured as follows. a) Instead of using the light guide plate devices 10, 20, and 30 as a backlight of a liquid crystal display device, the light guide plate device is used as a backlight of another electronic device, a backlight of a signboard, or an arbitrary lighting device. b) The light guide plate 13 is made of any other transparent material instead of being made of a transparent plastic such as an acrylic resin. Alternatively, composed of any other translucent material. c) In the second embodiment, a colored coating composed of an arbitrary pigment is used as the colored coating 21. d) In a modification of the second embodiment, an arbitrary material is used as a reflective material (for example, a silver film) to be attached. For example, other metal films, or films having a metal coating on a plastic substrate, and the like. e) In a modification of the second embodiment, an arbitrary reflective paint (paint containing metal powder) is used. f) Instead of changing the shape of the mounting leg 31 to the illustrated shape,
Any shape. g) Instead of changing the shape of the holding portion 32 to the illustrated shape,
Any shape. h) Instead of arranging the light source 12 on the side of the light guide plate 13, burying the light source 12 in the side of the light guide plate 13 i) Making the slit 16 continuously along the side edges 13b, 13c, 13d Provide intermittently instead of providing.

[0028]

According to the light guide plate device of the present invention, the following effects can be obtained. According to the light guide plate device of the first aspect, since the light guide plate is provided with the slit near the side edge, the light that enters the light guide plate from the light source, travels through the light guide plate, and reaches the slit is formed. The light can be reflected inward of the light guide plate. Therefore, it is possible to prevent the light incident from the light source into the light guide plate from being dissipated, and to improve the luminance in the light emitting region. Therefore, sufficient luminance can be ensured even with a small light source, and downsizing of the light guide plate device can be achieved. Moreover, the mirror surface is applied to the wall surface located on the inner side of the slit, so that the light reaching the slit can be effectively reflected toward the inner side of the light guide plate. In addition, the light guide plate has a cable for the light guide plate device.
Since the mounting legs for the sing are formed, the light guide plate
When attaching to the casing, additional members are required.
And mounting can be performed easily.
Therefore, the number of parts can be reduced and manufacturing can be performed easily.
The manufacturing cost can be reduced. I
The light guide plate device can be made compact.
You. Further, the light guide plate holds the illuminated body on the light emitting surface side.
Holding part for holding the illuminated body
Without the need for additional members.
In addition, mounting can be easily performed. Moreover, the light guide plate
The arrangement can be made compact. According to the light guide plate device of the second aspect, since the wall surface located on the inner side of the slit is colored, light reaching the slit can be effectively directed to the inner side of the light guide plate. Can be reflected. According to the light guide plate device of the third aspect , since the reflective material is attached or applied to the wall surface located on the inner side of the slit, the light reaching the slit is transmitted to the inside of the light guide plate. It can be effectively reflected to one side.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a light guide plate device of the present invention.

FIG. 2 is a cross-sectional view of the light guide plate device of FIG. 1 taken along the line AA in FIG.

FIG. 3 is an operation explanatory view of the light guide plate device shown in FIG. 1;

FIG. 4 is a sectional view showing a second embodiment of the light guide plate device of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the light guide plate device of the present invention.

FIG. 6 is a perspective view showing a conventional light guide plate device.

[Explanation of symbols]

 Reference Signs List 10 light guide plate device 11 casing 12 light source 13 light guide plate 13a one side edge 13b side edge 13c side edge 13d side edge 14 light emitting surface 15 reflection surface 16 slit 16a wall surface 20 light guide plate device 30 light guide plate device 31 mounting leg 32 holding portion 33 liquid crystal Display (illuminated object)

Claims (3)

(57) [Claims] 1. A light source, wherein the light source is arranged along at least one side edge, and has a rectangular plate in a plan view having a light emitting surface on a front surface and a reflective surface on a back surface, and receives the light from the light source. a light guide plate apparatus der comprising a light guide plate for by the light is reflected by the reflective surface is emitted from the light emitting surface is, the light guide
In the plate, the light guide plate is attached to the casing of the light guide plate device.
The illuminated body is attached to the mounting leg for
A holding portion for holding the light guide plate;
, The said light sources along the side edges that are not disposed, at a position separated from the side edge inwardly, a light guide plate apparatus slits are formed, located on the inner side of the slit
A light guide plate device , wherein a mirror surface is applied to a wall surface to be formed . 2. A light guide plate apparatus according to claim 1, the wall surface located on the inner side of the slit, the mirror
A light guide plate device characterized by coloring instead of surface processing . 3. The light guide plate device according to claim 1, wherein the wall surface located inside the slit is affixed or coated with a reflective material instead of the mirror finishing.
And a light guide plate and wherein the are.