JPH095740A - Frame body for holding light guide plate - Google Patents

Abstract

PURPOSE: To reduce the increase of luminance and the luminance irregularity of the light outgoing surface of a light guide plate. CONSTITUTION: A frame body 4 is constituted of a white system member and also black processing 44 is performed on the rear of a frame part 41 covering the external peripheral part of the light outgoing surface 31 of the light guide plate 3. Thus, the light outgoing from the side surface of the plate 3 is reflected by the body 4, so that the luminance of the light outgoing surface can be increased; and also the light on the part 41 on the peripheral part of the light outgoing surface is absorbed by a black part, so that the increase of the luminance occurring on the peripheral part of the light outgoing surface is restrained and the luminance irregularity on the light outgoing surface can be reduced.

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 holding frame for holding a light guide plate used for surface illumination or the like.

[0002]

2. Description of the Related Art In a flat panel display device represented by a liquid crystal display or the like, a surface illumination device is generally used as its light source. In this surface lighting device, a light guide plate such as an acrylic plate is used to spread the light of the linear light source in a plane, and a frame body is used to position and hold the light guide plate and the components attached thereto. To be And, this frame is generally made of a black resin.

[0003]

However, when the frame body is made of black resin, unnecessary light leakage can be prevented, but usable light emitted from the light source is also absorbed. It has been found that this causes a decrease in brightness. Therefore, it is an object of the present invention to simultaneously increase the brightness of the light emitting surface and reduce the uneven brightness of the light emitting surface.

[0004]

The present invention is characterized in that the frame body is made of a white member, and the back surface of the frame portion which covers the outer periphery of the light emitting surface of the light guide plate is subjected to black treatment.

[0005]

According to the present invention, since the frame body is made of the white member, the light emitted from the side surface of the light guide plate is reflected by the frame body to increase the brightness of the light emitting surface.
Since the back surface of the frame part that covers the outer periphery of the light exit surface of the light guide plate is black-treated, the light that hits the frame part around the light exit surface is absorbed by the black part, and the increase in brightness that occurs around the light exit surface is suppressed. As a result, it is possible to reduce uneven brightness on the light exit surface.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to a case where it is applied to a surface illuminating device 2 used for a flat panel display such as a liquid crystal display 1 as shown in FIG. The liquid crystal display 1 is of a light transmissive type, and the surface lighting device 2 is arranged so as to be superposed on the back side thereof. The surface lighting device 2 is mainly configured by a light guide plate 3 having a rectangular shape in a plane, a linear light source (not shown) arranged so as to face a predetermined side surface of the light guide plate 3, and a frame body 4 for positioning and holding these. are doing.

The light guide plate 3 is mainly composed of an acrylic plate or the like having a high light-transmitting property, and the light emitting surface 31 thereof is provided as necessary.
The light diffusing treatment or the light diffusing member may be laminated on the upper surface, and the light reflecting member may be laminated on the back surface to enhance the light reflectivity.

The frame 4 is integrally formed of, for example, a white resin having good light reflectivity, and has a planar shape of a square shape so that the light emitting surface 31 is exposed at the center thereof. . The frame portion 41 forming the four sides of the frame body 4 is
A frame upper portion 42 facing the outer peripheral portion of the light emitting surface 31 of the light guide plate 3.
And a frame side portion 43 facing the side surface of the light guide plate 3. On the back surface of the frame upper portion 42, in order to absorb the light emitted from the light guide plate 3 and suppress the reflection, a black treatment for fixing the black member 44 by painting, printing, adhering or the like is performed as shown by the diagonal lines in FIG. I am giving it. This black treatment is best performed on the four frame upper portions 42 as shown in FIG. 1, but at least on the frame upper portion 42 on the side where the linear light sources are arranged,
If necessary, it may be applied to the frame upper portion 42 on the side facing the side on which the linear light source is arranged. The light guide plate 3 may be fixed to the frame body 4 via a bottom frame 5 provided separately.
It may be performed by a locking piece (not shown) provided on the.

In the above structure, the light emitted from the linear light source and guided to the light guide plate 3 is reflected by the bottom surface of the light guide plate 3 and emitted from the light emitting surface 31. Since the side surface of the light guide plate 3 is surrounded by the frame side portion 43 of the white frame 4, the light emitted from the side surface of the light guide plate 3 can be effectively reflected by the frame side portion 43, and the light emission surface It is possible to increase the brightness of 31. On the other hand, since the frame body 4 is made of a white member, if the back surface of the frame upper portion 42 that covers the outer peripheral portion of the light emitting surface 31 of the light guide plate 3 is left white, the frame upper portion 4
2 causes unnecessary reflection of the light emitted from the light emitting surface 31, and the brightness around the light emitting surface 31 is partially increased under the influence of this reflection, which hinders uniform illumination. Since the black member 44 is arranged on the back surface of the upper portion 42 to perform the black treatment, the light reflection by the frame body 4 is blocked by the black portion 44, and the uneven brightness of the light emitting surface 31 is effectively prevented. You can In addition, if the black processing is also applied to the side surface portions 45 facing each other with the light emitting surface 31 of the frame upper portion 42 interposed therebetween, the light reflection by the frame 4 can be further reduced, and the uneven brightness of the light emitting surface 31 can be further reduced. It can be reduced.

[0010]

As described above, according to the present invention, since the frame is made of the white member, the light emitted from the side surface of the light guide plate is reflected by the frame to increase the brightness of the light emitting surface. Since the back surface of the frame part that covers the outer periphery of the light exit surface of the light guide plate is black-treated, the light that hits the frame part around the light exit surface is absorbed by the black part, and the increase in brightness that occurs around the light exit surface is suppressed. As a result, it is possible to reduce uneven brightness on the light emitting surface and improve the illumination quality in the surface illumination device.

[Brief description of drawings]

FIG. 1 is a bottom view of a frame body according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the frame body according to the embodiment.

FIG. 3 is a cross-sectional view of a display device including a frame body according to an exemplary embodiment of the present invention.

[Explanation of symbols]

 3 Light guide plate 31 Light emitting surface 4 Frame 41 Frame part 42 Frame upper part 43 Frame side part 44 Black member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Taniguchi 3-201 Minamiyoshikata, Tottori City, Tottori Santo Electric Co., Ltd. (72) Toshiya Nishio 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Sanyo Denki Incorporated (72) Inventor Seiichi Nishimura 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A frame body for holding a light guide plate with its light emitting surface exposed, the frame body being made of a white member, and the back surface of a frame portion covering the outer periphery of the light emitting surface of the light guide plate. A frame for holding a light guide plate, characterized in that a black treatment is applied to the.