CN101571264B - LED backlight module - Google Patents

Abstract

The invention discloses an LED backlight module, which comprises: a light guide plate, the light guide plate has at least one light incident surface; at least one LED light source arranged opposite to the light incident surface of the light guide plate, and the LED light source has a Facing the light-emitting surface of the light-incident surface of the light guide plate, the LED light-emitting source is arranged at least on one side of the light-guide plate, and the light-emitting surface of the LED light-emitting source is set at an inclination angle greater than 0° and less than 90° relative to the light-incident surface of the light guide plate . Adopting the LED backlight module of the present invention can reduce the light mixing distance between adjacent LEDs in the existing LED backlight technology, reduce or even eliminate existing dark areas, save costs, and reduce device heat generation.

Description

LED backlight module

technical field

The invention relates to an LED backlight module, in particular to an LED backlight module for a liquid crystal display device.

Background technique

Liquid crystal display devices have the characteristics of light weight, thin thickness, low power consumption and low radiation. They have been widely used in information technology, multimedia technology and other fields, and have gradually become the mainstream of various display devices. Since the liquid crystal panel itself does not emit light, a backlight module is required to provide a light source for it. Because LEDs (light emitting diodes) have the characteristics of no pollution, long life, shock resistance, impact resistance and no pollution, LEDs have been widely used in backlight modules for mobile phones, mobile phones, PDAs, and display screens. In recent years, due to the advancement of technology, the brightness of LED has been greatly improved, and it has become the choice of backlight for medium and large-sized liquid crystal display devices. The demand for LED as a backlight source for liquid crystal display devices is increasing.

LEDs are used as the backlight source of liquid crystal display devices. In medium and large sizes, the arrangement method is to arrange a certain number of LEDs on one side or both sides of the backlight unit of the liquid crystal module, or in a direct type in large sizes.

FIG. 1 is a schematic diagram of a liquid crystal display structure of an edge-lit LED backlight module in the prior art. The device includes an LED light source 10, a light guide plate 30, a frame 40, a reflection device 50, a liquid crystal screen 100 and a set of optical films (not shown). The frame 40 accommodates the light guide plate 30 , the LED light source 10 , the reflection device 50 , the liquid crystal screen 100 and the optical film. The light guide plate 30 has a light incident surface, the reflective surface of the reflective device 50 is disposed opposite to the light incident surface of the light guide plate 30 , and the LED light source 10 is disposed between the light guide plate 30 and the reflective device 50 .

Because the LED light emitting source 10 is a point light source, and the LED light emitting surface has a certain light emitting angle a, a certain distance is set between two adjacent LED light emitting sources 10. When the light emitted by the LED light emitting source 10 leaves the light emitting surface of the LED light emitting source 10 for a certain distance, The light is mixed with the light emitted by adjacent LED light emitting sources 10 , and the light mixing distance is related to the distance between adjacent LED light emitting sources 10 . Before two adjacent LED light sources 10 mix light, there is a dark area 20 between two LED light sources 10 . Therefore, when meeting the requirements of grayscale specifications, if the spacing between LEDs is large, the light mixing distance between adjacent LEDs will increase, and the dark area will also increase. In order to solve the problem of large light mixing distance and dark area before light mixing, one method is to increase the number of LED light emitting sources 10 and reduce the distance between LED light emitting sources 10 . This not only increases the cost, but also increases the power consumption of the backlight module. At the same time, the more LED light sources 10, the greater the heat generated by the backlight module and the heavier the backlight module. Another method is to increase the light mixing distance so that the dark area is distributed outside the light guide plate 30, which will increase the size of the backlight module, resulting in an increase in weight and cost, and the variable range of the light mixing distance is limited by the maximum of the overall structure. Due to restrictions such as appearance specifications, the method of increasing the light mixing distance is also very limited.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defects of large light mixing distance and dark area between two adjacent LEDs in the prior art, and provide an LED that can effectively reduce the light mixing distance and eliminate the dark area existing between two light-emitting sources. Backlight module.

The present invention solves the above-mentioned technical problems through the following technical solutions: an LED backlight module, which includes a light guide plate and at least one LED light source, the light guide plate has at least one light incident surface, and the LED light source has a direction The light emitting surface of the light incident surface of the light guide plate, the LED light emitting source is arranged at least on one side of the light guide plate, and it is characterized in that the light emitting surface of the LED light emitting source is at an angle greater than 0° and less than 90° relative to the light incident surface of the light guide plate tilt angle setting.

Wherein, the LED light source also has a slope adjacent to the light-emitting surface, and the slope is provided with a reflective film or coating that reflects light.

Wherein, the light-incident surface of the light guide plate is provided with several grooves which fully or partially accommodate the LED light source.

Wherein, the shape of the groove is L-shape or V-shape.

Wherein, the light guide plate has a reflective surface connected to the light incident surface, and the reflective surface is provided with a reflective film or coating that reflects light.

Wherein, the appearance of the LED light emitting source has a light output surface obliquely facing the light incident surface of the light guide plate, and the cross section of the appearance of the LED light emitting source is trapezoidal or triangular.

Wherein, the LED light emitting source has a reflective surface connected to the light emitting surface of the LED light emitting source, and the reflective surface is provided with a reflective film or coating that can reflect light.

Wherein, the LED light source is arranged on two opposite sides or adjacent two sides of the light guide plate, or is arranged on four sides of the light guide plate.

Wherein, the LED light source is any one of white LED, green LED, red LED and blue LED or a combination of at least two or more.

The positive progress effect of the present invention is:

1. Effectively reduce the light mixing distance between adjacent LEDs in the existing LED backlight technology;

2. Eliminate the dark area between two adjacent LED light sources;

3. The number of LED light sources used can be reduced by adopting the present invention, thereby saving costs and reducing device heat generation.

Description of drawings

FIG. 1 is a top view of the structure of a liquid crystal display device of an LED backlight module in the prior art.

FIG. 2 is a top view of the structure of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram of an improved arrangement of LED light sources in FIG. 2 .

FIG. 4 is a schematic diagram of an improved structure of the light guide plate of the LED backlight module in FIG. 2 .

Fig. 5 is an enlarged view of the structure of part A in Fig. 4 .

FIG. 6 is a schematic diagram of another improved structure of the light guide plate of the LED backlight module in FIG. 4 .

Fig. 7 is an enlarged view of the structure of part B in Fig. 6 .

Fig. 8 is a structural top view of the second embodiment of the present invention.

FIG. 9 is a schematic diagram of an improved structure of the LED backlight module in FIG. 8 .

FIG. 10 is a schematic diagram of the structure of the LED backlight module in FIG. 2 when it is arranged on both sides of the light guide plate.

FIG. 11 is a schematic diagram of another structure in which the LED backlight modules are arranged on both sides of the light guide plate in FIG. 2 .

Detailed ways

The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings to describe the technical solution of the present invention in detail.

Embodiment one

2 is a top view of the structure of the first embodiment of the present invention. As shown in FIG. Diaphragm (not shown). The light guide plate 202 has a light incident surface 204 , and the reflection surface of the reflection device 205 is disposed opposite to the light incident surface 204 of the light guide plate 202 . The LED light source 201 is arranged between the reflection device 205 and the light incident surface 204 of the light guide plate 202, and the light output surface of the LED light source 201 is inclined towards the light incident surface 204 of the light guide plate 202 and arranged at a certain angle b, and the angle b is greater than 0 ° and less than 90°.

Fig. 3 is a schematic structural diagram of an improved arrangement of the LED light source 201 in Fig. 2, as shown in Fig. The inclined surface 220) is provided with a reflective film with a high reflection effect on light, and the reflective film can be glued on the inclined surface 220 of the LED light source 201 or on the light guide plate 202 corresponding to the LED light source 201. It is also possible to apply a layer of coating with a high reflective effect on light on the inclined surface 220 or on the light guide plate 202 corresponding to the inclined surface 220 . In this way, the light emitted by the adjacent LED light sources 201 enters the light guide plate 202 after being reflected by the slope 220 . This structure can reduce the light loss when all the light emitted by the LED light source 201 is not incident on the light incident surface 204 of the light guide plate 202 due to the large included angle b.

As shown in FIGS. 4 to 5 , on the light incident surface 226 of the light guide plate 222 corresponding to the LED light source 201 , there is a V-shaped groove that completely or partially accommodates the LED light source 201 , and the LED light source 201 completely or partially in the groove. The shape of the groove can also be other L-shaped or other geometric shapes that can completely or partially accommodate the LED light source 201 .

As shown in Figures 6 to 7, in order to save costs and reduce the light loss of adjacent LED light sources 201, after grooves are made on the light incident surface 226 of the light guide plate 222, it is formed to be connected to the light incident surface 225 as shown in Figure 6 The reflective surface 227 is pasted with a reflective film with high reflective effect on light or coated with a coating with high reflective effect on light, so that the reflective surface 227 has high reflective effect on light. In this way, the light loss of the adjacent LED light source 201 can be reduced through the reflection of the reflective surface 227 with a reflective film or reflective coating, and the reflective device 205 in Figure 4 can be omitted to save costs, forming 6 shows the backlight module without the reflection device 205.

Embodiment two

As shown in FIG. 8 , the backlight module of the present invention includes: at least one LED light source 310, the appearance of which LED light source 310 has a light output surface inclined towards the light incident surface 204 of the light guide plate 202; a reflection device 205, A light guide plate 202, a frame 203 and a set of optical films (not shown). The LED light source 310 is disposed between the reflection device 205 and the light incident surface 204 of the light guide plate 202 , and the light output surface of the LED light source 310 is inclined toward the light incident surface 204 of the light guide plate 202 . In this embodiment, the LED light source 310 has a trapezoidal shape in cross section.

FIG. 9 is a schematic diagram of another improved structure of the LED light emitting source 310 in FIG. 8. As shown in FIG. 9, the appearance of the LED light emitting source 320 of this structure has a light-emitting surface on an oblique side and a reflective surface 230 connected to the light-emitting surface. By adhering a reflective film with a high reflective effect on light on the reflective surface 230, or coating a pair of coatings with a high reflective effect on light on the reflective surface 230, the reflective surface 230 has a high light reflective effect. Reflex action. In this way, when the light emitted by the adjacent LED light source 320 is incident on the reflective surface 230 , it is reflected by the reflective surface 230 and then enters the light guide plate 202 , reducing the light loss of the adjacent LED light source 320 . In this embodiment, the exterior cross section of the LED light source 320 is triangular, and the exterior cross section of the LED light source 310 may also be other polyhedron shapes including a light exit surface obliquely facing the light incident surface 204 of the light guide plate 202 .

Figures 10 to 11 are schematic diagrams of two different inclination ways of arranging the LED light source 201 on opposite sides of the light guide plate 202. This kind of arrangement of the LED light source 201 can be adopted in the first embodiment or the second embodiment. .

In this embodiment, the LED light source may be any one of white LEDs, green LEDs, red LEDs, and blue LEDs or a combination of at least two or more.

In this embodiment, the appearance of the LED light source is not limited to the style and position shown in this figure. The LED light sources can also be arranged on opposite sides or adjacent two sides or four sides of the light guide plate.

In addition to being used in liquid crystal display devices, the above-mentioned LED backlight module can also be used as a light source in other applications, such as directly as a light source for lighting.

Although the specific implementations of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or changes can be made to these implementations without departing from the principle and essence of the present invention. Revise. Accordingly, the protection scope of the present invention is defined by the appended claims.

Claims (9)

1. An LED backlight module, comprising a light guide plate and at least one LED light source, the light guide plate has at least one light incident surface, the LED light source has a light exit surface towards the light incident surface of the light guide plate, the LED light The light source is arranged at least on one side of the light guide plate, and the light emitting surface of the LED light emitting source is set at an inclination angle greater than 0° and less than 90° relative to the light incident surface of the light guide plate. There are at least two LED light emitting sources, and the LED light emitting source The light source also has a slope adjacent to the light-emitting surface, which is characterized in that the light-emitting surfaces of two adjacent LED light-emitting sources are inclined in the same direction, and the slope connected to the light-emitting surface of the previous LED light-emitting source is connected to the next LED light-emitting source. The light-emitting surface of the LED light-emitting source is opposite, so that a part of the light emitted by the latter LED light-emitting source is irradiated on the slope connected to the light-emitting surface of the previous LED light-emitting source and opposite to the light-emitting surface of the latter LED light-emitting source. A reflective film or coating that reflects light is provided, and the light loss of adjacent LED light sources is reduced through the slope of the reflective film or reflective coating. 2 . The LED backlight module according to claim 1 , wherein the LED light sources are arranged on opposite sides or adjacent two sides of the light guide plate, or are arranged on four sides of the light guide plate. 3 . 3. The LED backlight module according to claim 2, wherein the LED light source is any one of white LEDs, green LEDs, red LEDs and blue LEDs or a combination of at least two or more. 4. An LED backlight module, comprising a light guide plate and at least one LED light source, the light guide plate has at least one light incident surface, the LED light source has a light exit surface facing the light incident surface of the light guide plate, the LED light The light source is arranged at least on one side of the light guide plate, and the light emitting surface of the LED light emitting source is set at an inclination angle greater than 0° and less than 90° relative to the light incident surface of the light guide plate, and there are at least two LED light emitting sources, which are characterized in that , the light-emitting surfaces of two adjacent LED light-emitting sources are inclined in the same direction, and there are several grooves that completely or partially accommodate the LED light-emitting sources on the light-incoming surface. The shape of the grooves is L-shaped or V-shaped. The light-incident surface on the groove opposite to the light-emitting surface of the LED light-emitting source, and the reflective surface connected to the light-incident surface on the groove opposite to the light-emitting surface of the LED light-emitting source, and the light-emitting surface of the previous LED light-emitting source The reflective surface connected to the opposite light-incident surface is opposite to the light-emitting surface of the latter LED light-emitting source, so that a part of the light emitted by the latter LED light-emitting source irradiates the light-emitting surface located on the groove and the light-emitting surface of the previous LED light-emitting source. The opposite light-incident surface is connected to the reflective surface opposite to the light-emitting surface of the latter LED light source. The reflective surface is provided with a reflective film or coating that reflects light. Or the reflective surface of the reflective coating, which reduces the light loss of the adjacent LED light source. 5 . The LED backlight module according to claim 4 , wherein the LED light sources are arranged on opposite sides or adjacent two sides of the light guide plate, or are arranged on four sides of the light guide plate. 6. The LED backlight module according to claim 5, wherein the LED light source is any one or a combination of at least two of white LEDs, green LEDs, red LEDs and blue LEDs. 7. An LED backlight module, comprising a light guide plate and at least one LED light source, the light guide plate has at least one light incident surface, the LED light source has a light exit surface facing the light incident surface of the light guide plate, the LED light The light source is arranged at least on one side of the light guide plate, and the light emitting surface of the LED light emitting source is set at an inclination angle greater than 0° and less than 90° relative to the light incident surface of the light guide plate. There are at least two LED light emitting sources, and the LED light emitting source The shape of the light source has a light-emitting surface inclined towards the light-incident surface of the light guide plate. It is characterized in that the light-emitting surfaces of two adjacent LED light-emitting sources are inclined in the same direction, and the cross-section of the shape of the LED light-emitting source is trapezoidal or Triangular, the LED light source has a reflective surface connected to the light emitting surface of the LED light source, the reflective surface of the previous LED light source is opposite to the light emitting surface of the latter LED light source, so that the light emitted by the latter LED light source Part of the light is irradiated onto the reflective surface connected to the light-emitting surface of the previous LED light-emitting source and opposite to the light-emitting surface of the latter LED light-emitting source. The reflective surface is provided with a reflective film or reflective film that reflects light. The coating reduces the light loss of the adjacent LED light source through the reflective surface attached with the reflective film or the reflective coating. 8 . The LED backlight module according to claim 7 , wherein the LED light sources are arranged on opposite sides or adjacent two sides of the light guide plate, or are arranged on four sides of the light guide plate. 9. The LED backlight module according to claim 8, wherein the LED light source is any one or a combination of at least two of white LEDs, green LEDs, red LEDs and blue LEDs.

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