JPH09281490A - Plane light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce a reflection sheet or a diffusion sheet for a plane light emitting device equipped with a light guide plate without requiring time or handling. SOLUTION: In this device, a light source 2 is disposed on at least one side of a light guide plate 1 having a reflection sheet 4 on the back surface so that the light emitted from the light source 2 is introduced through the light guide plate 1 to emit on the top surface of the light guide plate 1. In this method, the reflection sheet 4 consists of a reflection sheet main body 41 and a light absorbing member 42 which is formed like a belt with specified width near the light source side. This light absorbing member 42 has an adhesive area on at least one surface of the base body formed into like a belt having specified width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting device for emitting light emitted from a light source through a light guide plate.
For example, it is used for backside illumination of a liquid crystal display panel in a transmissive liquid crystal display device, a display panel for advertisements, and the like.

[0002]

2. Description of the Related Art Conventionally, in a surface emitting device in which a light source is arranged on at least one side of a light guide plate having a reflecting sheet on its back surface and light emitted from the light source is surface-emitted on the surface side of the light guide plate through the light guide plate. , A high-luminance part is formed in a strip shape on one side of the light guide plate on the light source side, and in order to prevent this, a strip-shaped part corresponding to the high-luminance part is formed on the one side part of the reflection sheet body on the light source side. The light absorbing member is disposed.

This light absorbing member is formed by laminating a pigment on one side of the reflection sheet main body by silk printing. If necessary, a double-sided tape is attached to the upper surface of the pigment formed as described above. The double-sided tape was attached to the back surface of the light guide plate.

[0004]

However, in the case where the pigment is silk-printed on one side of the reflection sheet body as in the above-mentioned conventional technique, various operations such as setting and printing of the reflection sheet body are required in the silk printing process. It was necessary, and there was a problem that it took time and effort. Further, as mentioned above, in the case of sticking the double-sided tape on the upper surface of the pigment,
There has been a problem that the above-mentioned silk printing process and the double-sided tape attaching process are required to be performed in two steps, which takes more labor and time.

[0005]

A surface emitting device according to claim 1 of the present invention has a light source arranged on at least one side of a light guide plate having a reflecting sheet on its back surface, and guides light emitted from the light source. In a surface emitting device that emits surface light on the front surface side of the light guide plate through a light plate, the reflection sheet includes a reflection sheet main body and a light absorbing member formed in a band shape with a predetermined width on one side of the reflection sheet main body that is a light source side. The light absorbing member is a member having an adhesive portion on at least one surface of the base material formed in the band shape having the predetermined width.

A surface emitting device according to claim 2 of the present invention is
A surface light emitting device in which a light source is disposed on at least one side of a light guide plate having a reflection sheet on the back surface and a diffusion sheet on the surface, and light emitted from the light source is surface-emitted through the light guide plate on the front surface side of the light guide plate. The diffusion sheet is composed of a diffusion sheet body and a light absorbing member formed in a band shape with a predetermined width on one side of the diffusion sheet body which is a light source side, and the light absorbing member has a band shape having the predetermined width. The formed base material has an adhesive portion on at least one surface.

The surface emitting device according to claim 3 of the present invention is
In a surface emitting device in which a light source covered with a light source reflection member is disposed on at least one side of a light guide plate, and light emitted from the light source is surface-emitted on the surface side of the light guide plate through the light guide plate. The member includes a light source reflection member main body and a light absorption member formed in a band shape with a predetermined width at a portion to be attached to the light guide plate which is an end edge of the light source reflection member main body. Is an adhesive having an adhesive portion on at least one surface of the base material formed in the band shape having the predetermined width.

[0008]

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

FIG. 1 shows the structure of a surface emitting device according to the present invention.

In the figure, reference numeral 1 is a light guide plate,
The light source 2 is disposed on one side of the. The periphery of the light source 2 is covered with a light source reflection member 3, and the light source 2
Light emitted from the light guide plate 1 is guided to the light guide plate 1 from a light incident surface 11 which is one side surface of the light guide plate 1.

A reflection sheet 4 is provided on the back surface of the light guide plate 1, and a diffusion sheet 5 is provided on the front surface side which is the visual field side, and is guided from the light source 2 to the light guide plate 1. Light is diffused evenly over the entire surface through the diffusion sheet 5,
Surface emission is performed with uniform brightness.

Reference numeral 6 in FIG. 1 is a lens sheet disposed on the diffusion sheet 5, and 7 is a double-sided tape to which each member is attached.

As shown in FIG. 2, the reflection sheet 4 has a reflection sheet main body 41 and a reflection sheet main body 41.
And a light absorbing member 42 formed on one side which is the light source side.

As shown in FIG. 3, the light absorbing member 42 is composed of a base material 42a and adhesive parts 42b and 42c formed on at least one surface (both surfaces in the drawing) of the base material 42a.

The base material 42a is of a gray type in consideration of the reflectance of light and the influence of heat.

The adhesive parts 42b and 42c are formed, for example, by attaching a transparent double-sided tape to both sides of the base material 42a.

The light absorbing member 42 thus constructed is
The base material 42a having double-sided tape adhered on both sides is prepared in advance to a certain size and cut into strips having a predetermined width, whereby a large amount and easy production is possible.

The light absorbing member 42 is attached to one side of the reflection sheet body 41 on the light source side by the adhesiveness of the adhesive portion 42b.

The reflection sheet 4 has the adhesive portion 42c.
It is directly attached to the light guide plate 1 due to its adhesiveness.

As a result, the conventional printing process becomes unnecessary, and the reflection sheet 4 can be easily manufactured by directly attaching the light absorbing member 42 to a predetermined position of the reflection sheet main body 41.

If the light absorbing member 42 of the reflection sheet 4 does not need to be attached to the light guide plate 1, the base material 42 is used.
The adhesive portion 42b may be formed only on one surface of a.

Further, the adhesive portion 42b may be formed by applying a transparent adhesive to one surface or both surfaces of the base material 42a.

Further, the light absorbing member 42 may be formed by adhering the one-sided or the both-sided tape with the adhesive having the same color as that of the above-mentioned base material.

FIG. 4 shows another structure of the surface emitting device of the present invention. The same members as those of the surface emitting device described above are designated by the same reference numerals, and the description thereof will be omitted.

In this surface emitting device, a light absorbing member 51 is attached to the diffusion sheet 5.

The light absorbing member 51 is the light absorbing member 4 described above.
The same effect as that of the light absorbing member 42 is obtained.

Although not shown, both the reflection sheet 4 and the diffusion sheet 5 provided with the light absorbing members 42 and 51 may be used.

Further, the order of the reflection sheet 4, the diffusion sheet 5, and the light source reflection member 3 arranged on the light guide plate 1 is not limited to the above-described example, and the light source reflection member 3 is arranged on the light guide plate 1 first. When the reflection sheet 4 is provided on the light source reflection member 3, or when the light source reflection member 3 is provided on the light guide plate 1, the diffusion sheet 5 is provided on the light source reflection member 3. In some cases, the light-absorbing member 3 may be used in the pasted portion which is the edge of the light-source reflecting member 3.

The surface emitting device having such a structure is used as a component of a transmissive liquid crystal display device by being arranged on the back surface of a liquid crystal display panel, for example.

[0030]

As described above, according to the present invention, a strip-shaped light absorbing member having a predetermined width is formed by a base material having an adhesive portion on at least one side of the base material, thereby providing a reflection sheet, a diffusion sheet, Alternatively, the production of the light source reflection member is only one step of attaching the light absorption member to each body, and can be easily produced without taking time and effort.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a surface emitting device of the present invention.

FIG. 2 is a perspective view showing a configuration of a reflection sheet.

FIG. 3 is a cross-sectional view showing a configuration of a light absorbing member.

FIG. 4 is a cross-sectional view showing another configuration of the surface emitting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light guide plate 2 Light source 3 Light source reflection member 4 Reflection sheet 41 Reflection sheet main body 42 Light absorption member 42a Base materials 42b, 42c Adhesive part 5 Diffusion sheet 51 Light absorption member

Claims (3)

[Claims] 1. A surface emitting device, wherein a light source is disposed on at least one side of a light guide plate having a reflection sheet on the back surface, and light emitted from the light source is surface-emitted through the light guide plate on the surface side of the light guide plate. The reflection sheet is composed of a reflection sheet main body and a light absorbing member formed in a band shape with a predetermined width on one side of the reflection sheet main body which is a light source side, and the light absorption member has a band shape with the predetermined width. A surface-emitting device having an adhesive portion on at least one surface of the formed base material. 2. A surface in which a light source is disposed on at least one side of a light guide plate having a reflection sheet on the back surface and a diffusion sheet on the surface, and light emitted from the light source is surface-emitted on the front surface side of the light guide plate through the light guide plate. In the light emitting device, the diffusion sheet is composed of a diffusion sheet main body and a light absorbing member formed in a band shape with a predetermined width on one side of the diffusion sheet main body which is a light source side. A surface emitting device comprising an adhesive portion on at least one surface of a base material formed in a band shape having a predetermined width. 3. A surface emitting device in which a light source covered with a light source reflection member is disposed on at least one side of a light guide plate, and light emitted from the light source is surface-emitted through the light guide plate on the surface side of the light guide plate. The light source reflection member includes a light source reflection member main body and a light absorption member formed in a band shape with a predetermined width in a portion to be attached to the light guide plate, which is an edge of the light source reflection member main body. The surface-emitting device is characterized in that the light absorbing member has an adhesive portion on at least one surface of the base material formed in a band shape having the predetermined width.