JPH10246814A - Back light device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back light device having good assembling workability. SOLUTION: In this back light device 1 provided with a light transmitting plate 2, a linear light source 3 arranged on the side surface of the body 2, a flexible reflection sheet 4 bent to be U-shaped so as to hold one end of the plate 2 and the linear light source 3, and a frame body 5 supporting the plate 2 and the light source 3 so that the light outgoing surface 2a of the plate 2 faces down; the upper surface of the body 2 is connected with the frame body 5 through a connecting member 11, and also a position 13 where the plate 2 and the member 11 are fixed is kept away from a position where the sheet 4 and the member 11 are superposed. When the flexible reflection sheet provided with a conductive member is used, an insulating film 11 is arranged to cover the sheet 4 positioned on the upper surface side of the plate 2, and the plate 2 and the frame body 5 are connected through the film 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge light type backlight device suitable for illuminating a thin display device such as a liquid crystal display device.

[0002]

2. Description of the Related Art In an edge light type backlight device (Japanese Utility Model Laid-Open No. 3-37420), a linear light source is disposed on a side surface of a light guide, and a flexible reflective light is provided so as to surround the linear light source. The sheet is bent and arranged in a U-shape. These are arranged and fixed on a support frame and assembled.

[0003]

However, in the state where the light guide, the light source, and the like are arranged on the support frame, they are not fixed. Problems such as disassembly of the body and the light source coming off the frame body and the like, as well as damage of the light guide and the light source occur. In addition, when a flexible reflective sheet with a conductive member sandwiched between insulating transparent films by thinning a highly reflective metal such as aluminum as a reflective sheet is used, the metal portion from the end of the reflective sheet is used. Since there is a case where the electric circuit component is exposed, depending on the structure of the display device to be illuminated, a short circuit of the electric circuit component via the exposed metal may occur.

Accordingly, an object of the present invention is to provide a backlight device with good assembling workability. Another object is to prevent a short circuit of an electric component due to the conductive member when a flexible reflective sheet with a conductive member is used as the reflective sheet. Another object is to prevent the reflection function of the reflective sheet from being reduced when the insulating film is fixed to prevent a short circuit, and to keep the state of the light emitting surface favorable.

[0005]

SUMMARY OF THE INVENTION The present invention provides a light guide, a linear light source disposed on a side surface of the light guide, and a U-shape sandwiching one end of the light guide and the linear light source. In a backlight device comprising: a flexible reflective sheet bent into; and a frame supporting the light guide and the linear light source such that a light exit surface of the light guide faces downward. The upper surface of the light guide and the frame are connected via a connection member, and the fixing position of the light guide and the connection member is set to a position avoiding the position where the reflection sheet and the connection member overlap. And

Further, according to the present invention, a light guide, a linear light source disposed on a side surface of the light guide, and a U-shaped bend so as to sandwich one end of the light guide and the linear light source. In a backlight device comprising: a flexible reflective sheet with a conductive member; and a frame supporting the light guide and the linear light source such that a light emitting surface of the light guide faces downward. An insulating film is disposed so as to cover the reflection sheet located on the upper surface side of the light guide, and the light guide and the frame are connected via the insulating film.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a backlight device 1,
FIG. 2 is a sectional view taken along line AA of FIG.

The backlight device 1 includes a light guide 2, a linear light source 3 disposed on a side surface of the light guide 2, and the light guide 2.
And a flexible reflecting sheet 4 bent in a U-shape so as to sandwich the linear light source 3 and the light guide 2 so that the light exit surface 2a of the light guide 2 faces downward. And a frame 5 that supports the shape light source 3.

The light guide 2 can be constituted only by a transparent light guide plate 6 such as an acrylic plate, but in this example,
A reflecting plate 7 is arranged on the upper surface to be the light reflecting surface 2b, and a light diffusing sheet 8 and, if necessary, prism sheets 9 and 9 are laminated and arranged on the lower surface to be the light emitting surface 2a.

The flexible reflection sheet 4 has a structure in which a conductive member (metal) such as aluminum having good reflectivity is thinned and sandwiched between transparent films having high electrical insulation. However, a film having a structure in which a highly reflective insulating member layer is added to a transparent film may be used. The reflection sheet 4 has one end fixed to the light exit surface 2a side of the light guide 2 with an adhesive such as a double-sided adhesive, and the other end connected to the light reflection surface 2b of the light guide 2 with a double-sided adhesive. The light source 3 is fixed by an adhesive, and is maintained in a state of keeping a certain distance from the light source 3 so as to surround the light source 3 in an arc shape. Here, it is preferable to maintain a constant interval between the light source 3 and the reflection sheet 4 by using one to three ring-shaped interval members 10 attached to the light source 3 in order to increase the reflection efficiency.

The upper surface of the light guide 2 and the side surface of the frame 5 are fixed via a connecting member 11 made of an electrically insulating film. The connecting member 11 has a cover portion 11 a having a size large enough to cover the reflection sheet 4 located on the upper surface side of the light guide 2, and is bent to the side surface of the frame 5 and fixed to the frame 5. It has a substantially T-shape consisting of a mounting piece 11b. The connecting member 11 is first attached to the mounting piece 11b.
Is fixed to the side surface of the frame 5 with an adhesive 12 such as a double-sided adhesive, and then the cover portion 11a is bent so as to cover the reflection sheet 4 located on the upper surface side of the light guide 2, and the front end portion thereof is double-sided. It is fixed to the upper surface of the light guide 2 by an adhesive 13 such as an adhesive. Here, when the connection member 11 and the light guide 2 are fixed on the reflection sheet 4, the reflection sheet 4 may be wrinkled due to the force applied to the connection member 11 and the reflection function of the reflection sheet 4 may be reduced. In order to prevent this, the fixing position of the connecting member 11 and the light guide 2, that is, the mounting position of the adhesive 13 is set to a position avoiding the position where the reflective sheet 4 and the connecting member 11 overlap in a plane. . As a result, even if an extra force is applied to the connecting member 11, the force is not applied to the reflection sheet 4, so that the shape of the reflection sheet 4 can be kept in an initial state with good reflection efficiency.

As described above, since the light guide 2 and the frame 5 are connected by the connecting member 11, the connecting member 11 is displaced with respect to the frame 5 during the assembling work, or the light guide 2 is displaced. It functions to prevent the falling off.

In addition, as a result of using the above-described conductive member having a structure in which the conductive member is sandwiched between transparent films, the conductive member is exposed from a part of the reflective sheet 4. However, since the connecting member 11 is formed of an insulating film and the upper surface of the reflective sheet 4 is widely covered by the cover 11a, the electric circuit components can be appropriately arranged above the reflective sheet 4. That is,
Since the connecting member 11 has an electrical insulating function in addition to the connecting function, the area above the connecting member 11 can be effectively used as a space for arranging electric circuit components.

The backlight device 1 can be used by being incorporated in a display device such as a liquid crystal display device as surface illumination in such an assembled state. However, the light guide 2
In order to further strengthen the mounting state of the light guide 2, a separate frame (not shown) for pairing with the frame 5 and holding the light guide 2 is prepared, and the separate frame holding the light guide 2 is prepared. It is preferable that the backlight device 1 is configured by fixing the frame member 5 with screws or the like, and the backlight device 1 is incorporated in a display device.

[0015]

According to the present invention, a light guide, a linear light source disposed on a side surface of the light guide, and a U-shaped bend are formed so as to sandwich the one end of the light guide and the linear light source. A backlight device comprising: a flexible reflective sheet; and a frame supporting the light guide and the linear light source such that a light exit surface of the light guide faces downward. Since the upper surface and the frame are connected via the connecting member, the connecting member can prevent positional deviation of the light guide and the frame and can improve the assembling workability. And, since the fixing position of the light guide and the connecting member is set to a position avoiding the position where the reflecting sheet and the connecting member overlap, the reflecting sheet is prevented from being deformed due to the fixing of the connecting member, and the reflecting function of the reflecting sheet is improved. It can be kept in good condition.

Further, according to the present invention, there is provided a light guide, a linear light source disposed on a side surface of the light guide, and a U-shaped bent portion sandwiching one end of the light guide and the linear light source. A backlight device comprising: a flexible reflective sheet with a conductive member; and a frame supporting the light guide and the linear light source such that the light exit surface of the light guide faces downward. Since the insulating film is disposed so as to cover the reflection sheet located on the upper surface side of the light guide, the electric circuit components are disposed so as to overlap the reflection sheet, and the conductive member of the reflection sheet is partially exposed. Even so, the short circuit of the electric circuit component due to the exposed conductive member can be prevented by the insulating film. Since the light guide and the frame are connected via the insulating film, the light guide and the frame can be prevented from being displaced by the insulating film, and the assembling workability can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a backlight device according to the present invention.

FIG. 2 is an enlarged sectional view taken along line AA of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Back light apparatus 2 Light guide 3 Linear light source 4 Reflection sheet 5 Frame 11 Connecting member 12 Adhesive 13 Adhesive

Claims (2)

[Claims] 1. A light guide, a linear light source disposed on a side surface of the light guide, and a flexible U-shaped bent so as to sandwich one end of the light guide and the linear light source. A reflective sheet,
In a backlight device including a frame supporting the light guide and the linear light source such that a light emission surface of the light guide faces downward, a connection member connects an upper surface of the light guide and the frame. And a fixing position of the light guide and the connecting member is set to a position avoiding a position where the reflection sheet and the connecting member overlap with each other. 2. A light guide, a linear light source disposed on a side surface of the light guide, and a conductive member bent in a U shape so as to sandwich one end of the light guide and the linear light source. In a backlight device comprising: a flexible reflective sheet, and a frame supporting the light guide and the linear light source such that a light exit surface of the light guide faces downward. A backlight device, wherein the backlight device is arranged so as to cover the reflection sheet positioned on the upper surface side of the light guide, and the light guide and the frame are connected via the insulating film.